A Primer on Nuclear Safety: 1.4.3 Complexity and Three Mile Island

A Primer on Nuclear Safety:
1.4.3 Complexity and Three Mile Island
Supplemental View by Thomas H. Pigford

Introduction: As astonishing as it might seem Thomas Pigford was the only member of the Three Mile Island Commission who knew anything at all about nuclear safety. Pigford was Professor of Nuclear Engineering and Chairman of the Department of Nuclear Engineering at the University of California, Berkeley. He had also worked in reactor research at ORNL. Considering the availability of such luminaries as Edward Teller and Alvin Weinberg, both of whom had a long commitment to nuclear safety, as well as deep insight into the problems, the scientific and technical weakness of the Three Mile Island Commission and its staff is nothing short of astonishing. We ought to consider that the astonishing lack of nuclear safety knowledge on the Commission Staff and among the Commissioners to be proof of the incompetence of President Jimmy Carter as President of the United States. It is clear from some of Pigford's comments in his oral history. that some of the other Commissioners were nut cases. Russell Petersen wanted to eliminate Nuclear Power. Ted Taylor claimed to be doing research on solar heating of water, that he believed would make all commercial power plants obsolete. He expected to have his invention ready before the Commission's report was complete. Middletown, Pennsylvania Housewife Ann Trunk was sane, however.

Jimmy Carter appears to have paid little attention to the Commissions Report, did not ask any questions, and ignored their recommendations. Others, including reactor manufacturers, according to Pigford were much more responsive.

Pigford noted the amateurishness of the Commission staff:
"The staff report relies to a considerable extent upon excerpts from a book authored by E. Rolph without establishing the author's qualifications. Ms. Rolph did not testify in this investigation. The undue reliance upon this secondary source, without first establishing a primary source for its support and without establishing its reliability, is a further example of insufficient balance in this part of the investigation."

"In my view, the Rolph book does not express a comprehensive, accurate, and balanced knowledge of the NRC and of the nuclear industry."

Pigford in effect noted the extent to which Rolph unprofessional book, influenced not only the staff report, but also through the staff, the Commission's report.

In his oral history Pigford does state that he was able to request the placement of spacific individuals on his staffand indicated that he was satisfied with the staff he worked with.

Pigford correctly identifies that the the problem at Three Mile Island lay not with the the reactor system, but with the interplay between human judgement and what were relatively minor parts failures. Research on human judgement has demonstrated that the predictions of experts were less likely to correspond to outcomes, than predictions simply based on actuarial data. This research was based on situations in which people were not stressed by constant alarms, as the Three Mile Island operators were.

Pigford also noted that the accident tested a major nuclear safety concept, "defense in depth." Not only did the "Defense in Depth" work, but the overall outcome was better than previous speculative assessments of nuclear accidents (for example WASH-1400) had anticipated.

Supplemental View (to the Three Mile Island Commission Report) by Thomas H. Pigford

I generally concur with the conclusions and recommendations of the President's Commission on the Accident at Three Mile Island. However, some of the principal results of this investigation need clarification and discussion. Among these are some that warrant immediate, but necessarily limited, comment.

THE PERFORMANCE OF EQUIPMENT AND ENGINEERING SYSTEMS

The Commission has properly recognized that, with the very heavy emphasis upon equipment to attain reactor safety, there has been too little emphasis upon the adequacy of people to help achieve that safety. The lack of such people emphasis has been properly stressed in this report. However, that stress has now obscured the very important fact that, in spite of the very crucial errors of operators and supervisors at TMI-2, the safety equipment did indeed function. In spite of the open PORV, leaks in the vent gas system, and other equipment failures, the overall system of equipment was sufficiently good that, without the human errors, the accident at TMI-2 would have been only a minor accident.

The reactor containment and its auxiliary equipment did indeed function to protect the public. Except for the small fraction that escaped to the environment, the radioactivity was contained. The off-site radiation doses were small. We have found that the actual release of radioactivity to the atmosphere will have a negligible effect on the physical health of individuals. Equipment failures were not the proximate cause of the TMI-2 accident. The accident was, in fact, a demonstration that the equipment (?) effective.

Although there has been considerable speculation about how near TMI-2 came to a worse accident, our staff analyses show that even if all of the reactor fuel cladding had been oxidized to form hydrogen, or even if appreciable fuel melting or even a meltdown had occurred, the containment would still have survived and protected the public. The accident demonstrated that the "defense-in-depth" approach toward nuclear reactor safety has indeed yielded significant results.

The emphasis in this report upon equipment versus people obscures the fact that the equipment itself is only one product of the defense- in-depth or multiple-barrier design approach, which also encompasses the analysis of how equipment components must perform and how systems of equipment must operate. The accident demonstrated that this system of equipment performed better than expected. Earlier assumptions and studies by AEC/NRC (TID-14844 and WASH-1400) have suggested far greater core damage and greater releases of radioactivity from the fuel and into the containment under such degraded cooling conditions.

The accident also has demonstrated many areas wherein equipment modifications can result in further improvements in safety of existing and future reactors in this country.

These are important positive results from our investigation.

THE PEOPLE-RELATED PROBLEM

The nature of the people-related problems needs clarification. One such problem -- and a most serious one -- was the errors made by operators and operator-supervisors, whose training was insufficient in scope and understanding. Another was the failure of many individuals to respond adequately to the earlier experience from other reactors and to other advance information that might have alerted the operators and avoided the accident.

Another problem was the errors made by some NRC officials, who misinterpreted the release of radioactivity on March 30 and recommended evacuation, and who erroneously concluded on March 31 that the hydrogen bubble might explode. The public trauma from these mistakes resulted in severe but short-lived mental stress, which was evidently the only serious health effect of the accident.

Having identified the particular people problems involved, many of the necessary direct remedies are apparent. There seems to be some unwillingness to recognize that many of these remedies are already being implemented. The NRC and the nuclear industry have taken and are taking steps on a broad basis to analyze and rectify these problems, as evidenced by the post-TMI NRC bulletins and by the establishment of the utilities' Institute for Nuclear Power Operations (INPO) and the reinsurance program. After experiencing the shock and comprehending the cost of this accident, the nuclear industry clearly has set into motion programs to institute many of the remedies that this Commission seeks. The problem with "attitudes" emphasized in the Commission's report must refer largely to pre-TMI attitudes.

It is reasonable to expect that other such human-related problems, not uncovered by this investigation, may exist. That, and the need to instill and continue a strong emphasis upon reactor safety, suggest some of the broader institutional changes recommended in this study.

SCOPE AND LIMITS OF THE INVESTIGATION

The limits of this investigation and the effect thereof upon the Commission conclusions and recommendations need clarification.

This investigation was limited to the accident at TMI-2, and possible variations thereto, and, to a limited extent, similar transients at other places. The many other aspects of reactor safety were not investigated, although we do recommend that these be more systematically studied. The facts of the present investigation provide no basis for concluding that reactors are unsafe. They also show that, although more emphasis is needed on the analysis and planning for small-break accidents, the possibility of an accident of this type was known and had been analyzed and predicted prior to the TMI-2 accident. Therefore, any conclusions as to new fears of reactor safety do not arise from, and imply large extrapolations from, the facts of this investigation.

This investigation has not included a study of reactor siting. Consideration of the calculated "low population zone" occurred only in our consideration of its implication on the specification of radiation doses for evacuation decisions. Therefore, proposals made by some Commissioners to reverse existing site approvals in favor of more remote sites have no justification within the facts of this study.

We have recognized in this investigation that decisions as to whether or not safety improvements are to be implemented must be based, in part upon a weighing of the costs against the benefits. However, we did not evaluate the costs of possible safety modifications, nor did we evaluate the probabilities of some of the large hypothetical releases that have been postulated by some Commissioners. Such proposals, and claims as to risks therefrom, have no basis within the facts of this investigation.

We have not investigated the availability, cost, overall safety, and environmental effects of nuclear energy and of other energy alternatives. Nor have we investigated the effect of various energy alternatives upon the nation's economy and security. We have not examined the effect of a speed-up or delay of nuclear power upon the many energy problems that affect the nation. Therefore, proposals by some Commissioners to impose sanctions that afreet the availability of nuclear energy as an option are based upon their own personal extrapolations, which leap far beyond the facts of this investigation. The Commission, in its final consideration of the moratorium proposals, repudiated the issue by a vote of eight to four.

LACK OF INPUT FROM THOSE PARTS OF THE NUCLEAR INDUSTRY NOT INVOLVED DIRECTLY IN TMI-2

Through its investigation of the Nuclear Regulatory Commission, the Commission staff has uncovered problems and practices which have suggested extrapolations to those many parts of the nuclear industry not involved directly with the TMI-2 accident. However, little proof of the validity of these extrapolations has been established. Moreover, to my knowledge, no representatives of those other parts of the nuclear industry were interrogated or asked to present evidence on any of the relevant issues, except for one company interrogated within the narrow issue of the Beznau incident. This further limits the validity of the industry-wide extrapolations that are implied in many places in the report and that are implied in some of the moratorium recommendations still endorsed by some of the Commissioners.

ATTITUDES

The framing of the Commission's overall conclusion around the question of:

attitudes of the Nuclear Regulatory Commission and, to the extent that the institutions that we investigated are typical, of the nuclear industry . . .

requires comment and interpretation. "Attitudes," especially prior to TMI-2, were not directly examined, nor could they be. Valid conclusions can only be drawn on actions taken, i.e., problems addressed and not addressed, regulations issued and complied with, and the occurrence of events that reflect upon the adequacy of those processes. Even if attitudes could be assessed, it is not clear how they could be changed by any recommended rule, reorganization, or other mandated influence. It is more constructive to assume that attitudes are symptomatic of the forces at work in the systems, and it is those forces that must be addressed.

The actions already taken by the industry in setting up INPO, the Nuclear Safety Analysis Center, and the program of self-insurance against the cost of replacement power, with the self-policing actions thereby implied, signal a genuine, if somewhat belated, recognition of the need for greater effort to prevent nuclear accidents and to cope with their consequences. These actions show a significant change in industry attitude that can only be beneficial.

It becomes clear, as the theme of "attitudes" is developed in the Commission report, that what is of concern is an apparent failure of the system to incorporate an effective mechanism to assimilate lessons from plant experience and to incorporate the appropriate up-to-date technology, particularly as it applies to control room design, and to develop sufficiently trained and competent people to manage this technology. This is a more manageable and appropriate focus for the overall conclusion of this Commission.

I believe that such technology is being or will be used by the industry and that changes and improvements in design and operating procedure will be effected, not merely to satisfy critics nor to demonstrate attitudinal penitence, but on the basis of sound judgment resting on sound data.

COMMISSION JUDGMENTS ON OVERALL SAFETY

In its Overview, the Commission acknowledges that it has not examined "how safe is safe enough or the broader question of nuclear versus other forms of energy," recognizing the complexity of the issue and the limitations of staff. However, the Commission soon leaps this hurdle and speaks of the "risks that are inherently associated with nuclear power", and it holds that "equipment can and should be improved to add further safety." Even the conclusion that "accidents as serious as TMI should not be allowed to occur in the future" may imply that an assessment of risk and safety has been made. This conclusion is more understandable if interpreted in terms of what was really serious about this accident.

The only serious health effect was the mental stress resulting from the confusion and public misunderstanding concerning the March 30 release and the March 31 hydrogen bubble. The financial loss to the utility and ultimately to the rate payer is also serious.

Every technology imposes a finite degrees of risk upon society, both in its routine operation and in the occurrence of accidents. Over a long enough time period, even low probability accidents may occur. The essential question is the trade-off between the risks and the benefits. The Commission neither received any evidence nor reached any conclusions that the risks of nuclear power outweigh its benefits.

THE NRC "PROMOTIONAL PHILOSOPHY"

The NRC's assignment is indeed difficult, but not because of dichotomy of safety, on the one hand, and the industry's convenience, on the other. The problem is more complex. There is in each issue the element of how much cost, how many person years of expert analysis, and how much delay is justifiable to achieve an increment of safety. Seldom are these issues black and white, since the designers and engineers must recognize that absolute absence of risk in any project is unattainable, and that social costs accrue to both inaction and overreaction. Efforts to balance costs and benefits should not be considered evidence per se of a promotional philosophy.

It should be expected that industry will logically resist unwarranted changes proposed in the name of safety.

HYDROGEN FROM SMALL-BREAK LOCAS

Finding A.10 may be misinterpreted as suggesting that, because of the experience at TMI, the generation of large amounts of hydrogen gas is an inevitable consequence of small-break LOCAs. This misinterpretation leads to the erroneous conclusion that NRC overemphasis on large-break LOCAs, at the expense of small breaks, is what left the TMI operators unprepared for the hydrogen produced during the accident, since significant amounts of hydrogen are not predicted in the typical analyses of large breaks. Such inference is without basis. Large-break analysis or any-break analysis will predict the generation of large amounts of hydrogen whenever the cooling water added to the reactor core from the emergency systems is reduced to the extent that was done at TMI-2.

THE TWO-STEP LICENSING PROCESS

Finding G.6 implies that, in the two-step licensing process (construction permit and operating license), safety may be compromised due to the large financial commitment prior to the operating license stage, with the implication that insufficient information is known at the construction permit stage for an in-depth safety review. A review of actual license applications will reveal that major safety features are sufficiently described at the construction permit stage. The issuance of an operating license several years later facilitates consideration of appropriate technological developments and feedback from operating plants which may be factored into the design toward the end of the construction period. Safety review in licensing is not a discrete two step process. There is, and should be, continuing dialogue between the NRC staff and the applicant during this interim period.

SINGLE-FAILURE CRITERION Finding G.8.a that applicants "are not required to analyze what happens when two systems or components fail independently of each other" conveys some misunderstanding of the "single-failure" criterion. The requirement is that the applicant must show that applicable off-site radiation exposure limits will not be exceeded in the event of an accident initiated by:

a. any credible component failure, and in which

b. either all external or all internal power supply to the plant is lost, and

c. there is, in addition, failure of that single active component whose failure would most worsen the results of the accident.

Although confusingly called a "single-failure" criterion, it is clear that this criterion requires the assumption of at least three failures.

It is further required that if failure of one component causes failure of other components, the entire series of failures must be regarded as one failure. The single-failure criterion is applied on a system-by-system basis, which implies single-failure tolerance in each of the systems.

SAFETY-RELATED ITEMS

Finding G.5.b concerning NRC's handling of "safety-related" items needs clarification in several respects. First, the well-established practice of the NRC is to require that any component, system, or feature needed for the prevention or mitigation of a serious accident must meet documented requirements of quality, redundancy, testability, environmental qualifications, etc., and must be categorized as "safety-related." Although other components, systems, or features are classed as non-"safety related," they must meet requirements appropriate to their operational function. NRC practice is to subject all "safety-related" items to review. Additionally, non-"safety-related" items are reviewed by NRC to reassess their possible reclassification.

Second, in analyzing postulated accidents, one is not permitted to assume that an active non-"safety-related" item will be capable of performing its function. As a result, either an active item must meet "safety-related" requirements of quality, etc., or no credit can be taken for its functioning in an accident.

In the TMI-2 accident, it appears that the NRC's preoccupation with the "safety-related" item list was not the fault, but rather the safety analyses did not take into account the actual lack of training, the inadequate operating procedures and practices, and their potential capability for producing an accident if the PORV stuck open.

Finally, the NRC is in some degree responsible for the level of safety consciousness in the industry. In this sense, NRC's emphasis on "safety-related" categories has probably been less influential than its reluctance to give credit for safety innovations and its requirement that the industry comply with many technically unreasonable rules. These practices encourage the industry merely to comply with NRC rules.

With regard to finding G.8.C, it is not the reliance on "artificial categories of 'safety-related' items" which has caused NRC to miss important safety problems. Rather, it was the failure to recognize that some items not part of the safety system may challenge that system at an undesirable frequency. Moreover, the capability of the operators to defeat the safety system was not given sufficient attention. These important issues are apart from safety-system classification and the single-failure criterion.

PLANT INSTRUMENTATION Finding G.5.f does not provide a balanced account of all the considerations identified by the Atomic Industrial Forum (AIF) in its 1978 response to an NRC proposal to institute a new guide requiring a wider range of response for in-plant instrumentation, nor does it recognize the seeming lack of technical basis for the NRC request.

The relevance to the TMI-2 accident of the AIF response is not clear, since the range of the in-plant instrumentation at TMI-2 was adequate for diagnosis and plant control during the accident. Instead, the problem during the TMI-2 accident was that only part of the range of the in-plant instrumentation was displayed to the operators, and the manner of display was in some ways inadequate. Additionally, the operators misinterpreted some instrument readings. However, a greater range of instrument response might have aided the later assessment of the core damage that occurred.

BACKFITTING

Finding G.8.h, that there is no systematic backfitting review on a plant-by-plant basis of operating plants and plants under construction, appears to take too little account of the NRC's Systematic Evaluation Program (SEP), initiated more than 3 years ago. Under this program, operating plants have been categorized by NRC, issues have been identified by NRC, and information about older plants has been supplied to NRC by the utilities. In a number of cases, physical modifications of operating plants have been made in order to comply with updated NRC requirements. In some areas, such as that of the upgrading of emergency plans cited in the Commission's report, progress does appear to have been somewhat slow.

INDEPENDENT TESTING BY I&E

In finding G.9.a and recommendation A.ll.d, the recommended improvement of NRC's inspection and auditing of licensee compliance with regulations, and the need for major and unannounced on-site inspections of particular power plants, is logical. It calls for NRC to do more of what it already does and to do it better. In fact, NRC has, for over a year, stationed full-time inspectors at some operating nuclear power plants. At some plants, unannounced on-site inspections appear to be so frequent as to be commonplace.

The implication that NRC's I&E inspectors should do a substantial amount of independent testing of construction work and should place little reliance on work done by the utility is clearly impractical because of the enormous resources that would be required. Careful auditing of industry's testing is the only practicable and effective approach.

EMERGENCY PROCEDURES

In addition to the fact that some of the existing TMI-2 procedures were unworkable, as indicated in the Commission's report, the procedures did not provide a step-by-step pathway for identifying the problem implied by the information available in the control room. Given the philosophy that the operators had to adhere closely to written procedures, the unavailability of diagnostic procedures and training in their use was a significant factor among the causes of the TMI-2 accident.

THE MAJOR PROBLEMS WITH NRC'S APPROACH TO REACTOR SAFETY

The Commission report has identified many mistakes by NRC personnel in their handling of the TMI-2 accident and deficiencies in NRC's regulatory practices. However, this criticism does not reach some essential elements of the problem. I believe that the following are some of the more important problems at NRC:

• Lack of quantified safety goals and objective. When a safety concern is postulated, there is no yardstick to judge the adequacy of mitigating measures.

• Inability to set priorities and to allocate resources in proportion to the estimated risk to the public. In my view, a disproportionate effort is being required for some issues that have only a marginal impact upon risk to the public.

• Lack of experienced staff. An undesirably large proportion of NRC staff and management have little or no practical experience in designing or operating the equipment that they regulate.

• Arbitrary requirements. Too many of the NRC requirements are mandated without valid technical backup and value-impact analysis.

• A stifling adversary approach. The existing process inhibits the interchange of technical information between the NRC and industry. It discourages innovative engineering solutions.

• Ineffective evaluation of operations. NRC has no effective system for evaluating data from operating plants. Data should be analyzed systematically to identify trends and patterns.

• Lack of a comprehensive system approach to the whole plant. A large percentage of the NRC staff are specialists focusing upon narrow topics. There are relatively few systems engineers within NRC who can integrate individual safety features into an overall concept and who can place issues into perspective.

• An overwhelming emphasis on conservative models and assumptions. Realistic analyses are needed to identify the margins of safety and to aid competent decisions.

THE STAFF REPORT

The tight schedule and deadline for the Commissioners' report has allowed little opportunity for careful review of the staff reports upon which our findings are to be based. Some staff reports are not yet completed. There are several parts of some key staff reports with which I cannot agree, particularly the staff report on the NRC.

THE STAFF REPORT ON THE NUCLEAR REGULATORY COMMISSION

The staff report on the Nuclear Regulatory Commission is a companion document published by the Commission. Some deficiencies in this report are already reflected in earlier comments on findings and conclusions concerning the NRC. Having reviewed that report in search for understanding for many of the findings and conclusions adopted by this Commission, I noted several deficiencies, varying from technical error to unbalance in the investigation. Two examples are given below.

Performance Characteristics of Large Light-Water Reactors

The staff report contains generalities by an NRC staff member, who seriously questioned the state of knowledge of the performance characteristics of the larger light-water reactors in this country, an opinion apparently also echoed by some other individuals within NRC. The cited statement was adopted by the authors of this staff report. However, the staff report reflects no attempt by the staff to obtain evidence from the nuclear industry on this issue, even though the various companies in the nuclear industry are the parties impugned by the cited statements.

Statements were recently obtained from Saul Levine, director of NRC's Office of Nuclear Regulatory Research, and from two different companies that design light-water reactors and that are not connected with the TMI-2 accident. It should not be construed from reference to "economy of scale" that the regulators were being asked to accept reduced ; safety margins. Rather, the growth was largely achieved by adding more fuel assemblies of the same or similar volumetric and linear power density, and by adding more heat transfer loops having the same mechanical and hydraulic characteristics as in the plants previously licensed. Saul Levine said, "as far as I know, there have been no size-dependent factors found in the operation of large reactors to affect the safety of the plants adversely." There appears no supportable suggestion that safety was compromised as a result of the extrapolation of technology.

The unqualified acceptance of the cited testimony in the staff report is an indicator of insufficient balance in this part of the investigation.

Reliance on Books and Magazines

The staff report relies to a considerable extent upon excerpts from a book authored by E. Rolph without establishing the author's qualifications. Ms. Rolph did not testify in this investigation. The undue reliance upon this secondary source, without first establishing a primary source for its support and without establishing its reliability, is a further example of insufficient balance in this part of the investigation.

In my view, the Rolph book does not express a comprehensive, accurate, and balanced knowledge of the NRC and of the nuclear industry.

CONCLUDING STATEMENT

The rather extensive criticism of NRC in the Commission report, and as implied in this supplementary statement, should not obscure the central issue that primary responsibility for nuclear safety lies with the utility, shared to a large extent with the equipment suppliers and the architect engineers. This also reflects my view of the responsibilities for the TMI-2 accident.

However, these criticisms of both the industry and the NRC should not obscure the fact that in 480 reactor years of commercial nuclear power operation in the United States, there has still been no identifiable effect upon the physical health of the public, and that this record has been achieved by the industry and NRC -- the parties that have been criticized -- and under the system that has been criticized.

It must be emphasized that nothing learned from this investigation suggests that the nuclear power option should be curtailed or abandoned as a result of the TMI-2 accident.

Thomas H. Pigford

October 25, 1979

A note on Thomas Pigford: Pigford spent 2 years in Oak Ridge in the early 1950's. He was the brother-in-law of my father'slong time neighbor and Oak Ridger newspaper editor Dick Smyser. He was involved in the ANP project. Pigford described memories of his Oak Ridge days, including some observations on the ANP project in a UC Berkley oral history.

Milton Shaw's Nuclear Safety Failure

Milton Shaw believed that nuclear safety research was unneeded because rigorous attention to good engineering , proper training and adequate quality controlwould assure that a major accident would never occur. Yet the AEC during the Shaw era was not taking steps to assure that the good engineering , proper training and adequate quality control were emerging in the newly emerging nuclear industry. There was more than one way the AEC could have gone about this. For example, it could have taken the stance that monitoring of nuclear safety was its business, and instituted a vigorous program of design review, quality control monitoring, and monitoring for compliance throughout the industry. it did not do so. Alternatively the AEC could have taken the stance that nuclear safety was part of the business of the industry, and turned management of safety practices over to the industry. But even in a safety self management system, the AEC had a responsibility to insure that the nuclear industry understood what good safety practices were and how to carry them out. Investigations conducted after Three Mile Island revealed deficiencies in the safety aspects of reactor design, and inadequate operator training. The AEC's nuclear safety system had been a failure, and reforms to that safety system instituted by the NRC following the AEC's break up, had also failed.

Milton Shaw was quite mistaken in his assumption that good engineering , proper training and adequate quality control would prevent nuclear accidents because his safety scheme was not being applied by the AEC and the nuclear industry, and while he should have known that this was the case, he either did not know, or chose to ignore what he knew. In either case, Milton Shaw deserves, in no small measure, blame for The Three Mile Island accident, because after defining the AEC's policy on nuclear safety, he did not ensure that that policy was being carried out.

Investigation of the causes of the Three Mile Island accident revealed that the design of the reactors safety control system's human interface was poorly designed. Design flaws coupled with inadequate operator training lead to operator errors as the accident unfolded. These errors and their consequences, as Shaw had anticipated, had snowballed. Had the safety control system, which Shaw had anticipated, been in place no major accident would have occurred at Three Mile Island.

We must take Shaw's views about nuclear safety to have been shallow. Three Mile island demonstrated that his views on nuclear safety were not valid, in the absence of policies and practices they entailed. Yet Shaw did not insure that those policies and practices were in place.

The frustration of the scientific community, ad the emergence of the revolt of national laboratory scientists against Shaw's nuclear safety policy is understandable. Shaw;s policy was nothing short of crazy, and craziness on that scale can only lead to disaster.

Harvey Wasserman, Three Mile Island, and Logic

I have on numerous occasions documented the factual errors of nuclear critics Amory Lovins, Joe Romm, Mark Z. Jacobson, Ben Sovacool, David Biello, Frank Barnaby, Helen Caldicott, Jan Storm van Leeuwen, Ralph Nader, and David Brower. Not one of them based his or her case on an honest recounting of facts. In fact, as a group most of these people are no more truthful that the rightwing talk radio personalities are. (I would exclude Ben Sovacool and Frank Barnaby from this judgement,) I have gotten so cynical about the pseudo pro-environmentalists who recite shallow lies as their take on nuclear power, that I am shocked when I find a spokes person for some environmental group actually exhibit honesty and candor and demonstrates some understanding of nuclear technology. Usually anti-nuclear leaders act as if the truth does not matter, and they are morally entitled to recite their falshoods because of the evil embodied in nuclear power.

Most critics of nuclear power have failed to engage in even minimal dialogues on nuclear power with its defenders. Even worse they repeat the same mistaken idea over and over, even after being repeatedly informed of factual errors in their accounts. For example Ralph Nader records a conversation with a nuclear safety expert at Oak Ridge. From Nader's account of the conversation it would appear that the expert was trying to describe basic concepts of nuclear safety to Nader in relatively simple language, but Nader accused the expert of using jargon, and dismissed what he had to say. Nader got to talk mto Alvin Weinberg, in fact Weinberg and Nader's sister Clair were friends, but Nader refused to listen to anything Weinberg had to say. Weinberg befriended Amory Lovins, and frequently informed Lovins of his mistakes. Lovens payed not the slightest attention and has repeated the same errors till this day. When Helln Caldicott was confronted with some of her many well documented factual errors, she said that her critics were such morally degenerate people that she should not need to answer them, so she didn't.

But for towering mendacity we have the Rush Limbaugh of the anti-nuclear cause Harvey Wasserman, a pseudo-liberal. To understand exactly how dishonest Wasserman is we have to look at some of his anti-nuclear arguments.

Harvey Wasserman has told innumerable fibs while opposing nuclear power. For example, in February Wassermant told Amy Goodman and Patrick Moore,

We have $50 billion lined up in the Congress that needs to stop and not come out of the taxpayers' pocket, because, among other things, the reactors that these $50 billion would fund cannot come online in less than a decade.

Of course, the $50 billion were loan co-signs, not guifts from the treasury to the nuclear industry. The Congressional Budget office valued the loan co-signs at $500 million, but that did not exactly come out of the taxpayers pockets, that is what the CBO estimated the co-signs would cost thetax payers in loan defaults. Co-signing nuclear industry loans cost the taxpayers nothing in the present, but that is not the way Harvey told it. in his Daily Kos Blog Wasserman told his readers

The latest demand for a $50 billion taxpayer handout has been sleazed into the Senate budget bill. . . . This latest bailout incarnation has been widely tagged “nuclear pork” even in the right-wing Washington Times, which says the Senate accepted it “without debate, explanation or a recorded vote.”

Harvey knew what the facts were, but facts have never constrained him to tell the truth. Daily Kos commenter bryfry noted

This is just another hit-and-run diary by Wasserman, pushing the same idiotic points. He isn't going to stick around to respond [to critical comments].

Following the Three Mile Accident, everyone and his brother studied the people of the accident area to see if anyone was getting sick from radiation. There was a presidential commission appointed by Jimmy Carter who was no friend of the Nuclear Industry. The NRC had a study. So did the Environmental Protection Agency, Not to be outdone so did the Department of Health, Education and Welfare (now Health and Human Services), and we should not forget the one by the Department of Energy, Not to be out shown so did the State of Pennsylvania Department of Health which contacted 32,000 are citizens.. Not only did the University of Pittsburgh's Graduate School of Public Health (GSPH) do a study, but they did a 20 year follow up to make sure no one turned up with symptoms years after the fact. Epidemiologists from Columbia University thied to find ebvidence that the accident had made people sick. None of these studies cam up with anyone who had died or had even been made sick by the Three Mile Island accident.

The Columbia study did find find an increase in lung cancer down wind from Three Mile Island but when they looked at the reported radiation release it became clear that the exposure to Three Mile Island radiation could not account for the cancer increase observed. That meant that they could not say with any confidence that that the Three Mile Island accident had anything to do with the with the lung cancer increase. Now for most scientists that ends the story, but if you are a trial lawyer you might consider the Three Mile Island to big a target to not take a run at. So a law suit was filed, but the lawyers needed an expert who would say that the Columbia University interpretation of the data was wrong and that the data showed that living down wind from the accident was associated with an increased cancer risk.

The lawyers found a University of North Carolina epidemeologist, Steven Wing, who was willing to take a run at the Columbia data. Wing testified that the Columbia conclusions were based on the assumptions that reported radiation levels following the TMI accident were wrong,

"[u]nlike the original reports based on these data, our re-analyses (sic) assumed that absolute accident doses could have been large enough to produce measurable impacts on cancer incidence. . . ."

The plaintives' attorneys then attempted to argue that the radiation release levels were large enough to account for the cancer cases. There problem, however was the only thing they had to base this argument on was the observed cancer cases. But this is what is called in Logic a circular argument. Basically the plaintives were arguing with Wing's assistance that X level of radiation at causes cancer at rate Y, the TMI down wind survivor had cancer at rate Y. There fore they were exposed to X level of radiation. The argument is flawed because it uses its own assumption to prove that it is true. The argument really says, if we assume that something it must be true. This is downright silly.

For an example of this logic error, consider the argument that of President George W. Bush had a love affair with a donkey belonging to the Queen of Britain. If President had an affair with the Queen's donkey, he would have spent the night in Buckingham Palace, President Bush spent the night om Buckingham Palace, therefore he must have had an affair with the Queen's donkey.

Sylvia H Rambo, the Judge in the TMI class action case ruled:

The record presently before the court does not support the fundamental assumption made by Dr. Wing -- that doses were significantly higher than originally estimated. In the absence of this assumption, Dr. Wing himself admits that he would be unable to make a causal interpretation based upon his findings. Because Plaintiffs have presented no evidence in support of this assumption, the court finds the Wing cancer incidence study does nothing to assist Plaintiffs in creating a material factual dispute or meeting their burden of proof.

Thus Judge Rambo concluded,

The parties to the instant action have had nearly two decades to muster evidence in support of their respective cases. As is clear from the preceding discussion, the discrepancies between Defendants, proffer of evidence and that put forth by Plaintiffs in both volume and complexity are vast. The paucity of proof alleged in support of Plaintiffs, case is manifest. The court has searched the record for any and all evidence which construed in a light most favorable to Plaintiffs creates a genuine issue of material fact warranting submission of their claims to a jury. This effort has been in vain

Anyone who would dispute the Judges contention would face a daunting prospect that would require demonstration that there was credible evidence that radiation levels downwind of the TMI accident did reach a level that could have accounted for the observed cancer.

Here is what Harvey Wasserman argues:

cancer, leukemia, birth defects, stillbirths, malformations, spontaneous abortions, skin lesions, hair loss, respiratory problems, sterility, nausea, cataracts, a metallic taste, premature aging, general loss of bodily function and more can be caused by radioactive emissions of the type that poured out of TMI. And all such ailments have been documented there outside the corporate media.

Now where does Wasserman get this from?

University of North Carolina epidemiologist Dr. Stephen Wing.

The same Steven Wing who admitted on the witness stand that he had created a circular argument in order to link cancer cases with Three Mile Island radiation.

Yet Harvey Wasserman is claiming is that American corporate media lies when it claims that “no one died at TMI.” Wasserman does nothing more than recycle Steven Wing's argument that was discredited by Dr. Wing's own admission on the witness stand. Needless to say Wasserman did not repeat Wing's own damning statement about his evidence under cross examination.

Wasserman argues that

cancer, leukemia, birth defects, stillbirths, malformations, spontaneous abortions, skin lesions, hair loss, respiratory problems, sterility, nausea, cataracts, a metallic taste, premature aging, general loss of bodily function and more can be caused by radioactive emissions of the type that poured out of TMI. And all such ailments have been documented there outside the corporate media.

But in fact although those illness were documented, the link to TMI radiation was not, and that is the rub. Wasserman claims

Dr. Wing reports that levels of radiation-related disease significantly rose in the downwind area. Wing and three co-authors looked at statistics used in a major study by Columbia University and other sources. They concluded that — despite official denials — the numbers clearly indicate serious potential health effects.

This argument simply ignores Wing's damming admission on the witness stand. Thus Wasserman is using as proof a study that reaches its conclusions by a logical error. The study's author admitted the mistake. We know this is the case because the judge in the case pointed to the error as a critical point in her verdict in the case. It does not get any planer or more obvious than that. Yet Wasserman treats Wings findings as if they are sound, and beyond dispute.

June 1996, 17 years after the TMI-2 accident, Harrisburg U.S. District Court Judge Sylvia Rambo dismissed a class action lawsuit alleging that the accident caused health effects. The plaintiffs have appealed Judge Rambo's ruling. The appeal is before the U.S. Third Circuit Court of Appeals. However, in making her decision, Judge Rambo cited:

· Findings that exposure patterns projected by computer models of the releases compared so well with data from the TMI dosimeters (TLDs) available during the accident that the dosimeters probably were adequate to measure the releases.

· That the maximum offsite dose was, possibly, 100 millirem (1 mSv), and that projected fatal cancers were less than one.

· The plaintiffs' failure to prove their assertion that one or more unreported hydrogen "blowouts" in the reactor system caused one or more unreported radiation "spikes", producing a narrow yet highly concentrated plume of radioactive gases.

Judge Rambo concluded:

"The parties to the instant action have had nearly two decades to muster evidence in support of their respective cases.... The paucity of proof alleged in support of Plaintiffs' case is manifest. The court has searched the record for any and all evidence which construed in a light most favourable to Plaintiffs creates a genuine issue of material fact warranting submission of their claims to a jury. This effort has been in vain."

No one could demonstrate that any plausible evidence of adverse health effect from the Three Mile Island accident accept the stress which local residents suffered during and after the accident. This has not stopped Harvey Wasserman from repeatedly charging that "Three Mile Island killed people."

Now what can we say of Harvey? It is beyond credibility that he is unaware of the logical error upon which he basis his argument. Media personalities like left wing personality Amy Goodman simply ignore the issue of logic, and treat Wasserman as if he were a credible source. People who are blatantly irrational, and who disregard documented facts should not be treated as experts by the media, even if they say what media gatekeepers want to hear.

A Primer on Nuclear Safety: 1.4.2 Complexity and Three Mile Island

A Primer on Nuclear Safety:
1.4.2 Complexity and Three Mile Island
The Accident

Introduction: Nothing illustrates the complexity of the Light Water Reactor and the safety challenges it poses more than the Presidential Commission's report on the Three Mile Island accident. The words "Three Mile Island have become a Shibboleth for the anti-nuclear crowd. The anti-nuclear crowd believes that the words "Three Mile Island" with no other intellectual content is sufficient to both express and explain their opposition to nuclear power. For the anti-nuclear crowd, nuclear power exists out of time and space and thus there is not and there never can be a history of nuclear safety. Advocates of a probabilistic approach to nuclear safety, who hold a very different perspective, saw and continue to see the the Three Mile Island accident as an example of an possible but improbable set of circumstances leading to a nuclear accident. A historic view of the Three Mile Island accident would view that accident in terms of the lessons learned about nuclear safety from the accident.

The most important lesson from the accident was to take safety related decisions out of the hands of the operators, and place it in the hands of built in reactor passive safety systems. Nuclear safety research by reactor builders, has lead to ever safer reactor design. A General Electric description of its latest reactor design, the ESBWR describes, contains data reflecting the evolution of reactor safety.

The GE Boiling Water Reactor/4 was expected to have a core melt down once every 10,000 years.

The Boiling Water Reactor/6 included safety improvements and was expected to have a core meltdown once every 100,000 years.

The Advanced Boiling Water Reactor is expected to have a core meltdown once every 2,000,000 years.

Finally a core melt down is expected with the Evolutionary Simple Boiling Water Reactor once every 29,000,000 years.

To put the full implications of ESBWR safety into perspective, I would like to contrast the risk posed by an ESBWR core meltdown, to that caused u In contrast, the 1,500 square mile Yellowstone Caldera super volcano has a history of eruptions dating back 17 million years. The Yellowstone Caldera super volcano erupts every 600,000 to 800,000 years and it has been over 600,000 years since its last eruption. The last Yellowstone Caldera eruption sent a massive blew 240 cubic miles of rock and lava to bits and send an enormous cloud of volcanic dust high into the atmosphere. Such an eruption would kill millions of people, and virtually destroy the American economy. An eruption of the Yellowstone Caldera super volcano is between 50 and 300 times more likely than an ESBWR core melt down. The Yellowstone Caldera eruption could kill millions of people. The number of people killed and injured by a ESBWR accident is most likely 0. A Yellowstone Caldera super volcano would cause horrible suffering to most of the population of the United States. A ESBWR meltdown would cause extreme unhappiness in the head offices of some insurance companies. Guess which event the anti-nuclear crowd is most obsessed with? Hay some of them are related to insurance executives.

I might add that ESBRW safety feature in the very unlikely event of a core melt down, are superior to those of the Three Mile Island Reactor, which contained that accident without loss of live or injury. Thus there is a history of nuclear safety, and new reactor designs are far safer, than at the time of Three Mile Island.

From "Report of the President's Commission on The Accident at Three Mile Island"
Wednesday March 28, 1979
Part 1

In the parlance of the electric power industry, a "trip" means a piece of machinery stops operating. A series of feedwater system pumps supplying water to TMI-2's steam generators tripped on the morning of March 28, 1979. The nuclear plant was operating at 97 percent power at the time. The first pump trip occurred at 36 seconds after 4:00 a.m. When the pumps stopped, the flow of water to the steam generators stopped. With no feedwater being added, there soon would be no steam, so the plant's safety system automatically shut down the steam turbine and the electric generator it powered. The incident at Three Mile Island was 2 seconds old.

The production of steam is a critical function of a nuclear reactor. Not only does steam run the generator to produce electricity but also, as steam is produced, it removes some of the intense heat that the reactor water carries.

When the feedwater flow stopped, the temperature of the reactor coolant increased. The rapidly heating water expanded. The pressurizer level (the level of the water inside the pressurizer tank) rose and the steam in the top of the tank compressed. Pressure inside the pressurizer built to 2,255 pounds per square inch, 100 psi more than normal. Then a valve atop the pressurizer, called a pilot-operated relief valve, or PORV, opened -- as it was designed to do - - and steam and water began flowing out of the reactor coolant system through a drain pipe to a tank on the floor of the containment building. Pressure continued to rise, however, and 8 seconds after the first pump tripped, TMI-2's reactor -- as it was designed to do -- scrammed: its control rods automatically dropped down into the reactor core to halt its nuclear fission.

Less than a second later, the heat generated by fission was essentially zero. But, as in any nuclear reactor, the decaying radioactive materials left from the fission process continued to heat the reactor coolant water. This heat was a small fraction --just 6 percent -- of that released during fission, but it was still substantial and had to be removed to keep the core from overheating. When the pumps that normally supply the steam generator with water shut down, three emergency feedwater pumps automatically started. Fourteen seconds into the accident, an operator in TMI-2's control room noted the emergency feed pumps were running. He did not notice two lights that told him a valve was closed on each of the two emergency feedwater lines and thus no water could reach the steam generators. One light was covered by a yellow maintenance tag. No one knows why the second light was missed.

With the reactor scrammed and the PORV open, pressure in the reactor coolant system fell. Up to this point, the reactor system was responding normally to a turbine trip. The PORV should have closed 13 seconds into the accident, when pressure dropped to 2,205 psi. It did not. A light on the control room panel indicated that the electric power that opened the PORV had gone off, leading the operators to assume the valve had shut. But the PORV was stuck open, and would remain open for 2 hours and 22 minutes, draining needed coolant water -- a LOCA [loss of coolant accident] was in progress. In the first 100 minutes of the accident, some 32,000 gallons -- over one-third of the entire capacity of the reactor coolant system -- would escape through the PORV and out the reactor let-down system. Had the valve closed as it was designed to do, or if the control room operators had realized that the valve was stuck open and closed a backup valve to stem the flow of coolant water, or if they had simply left on the high pressure injection pumps, the accident at Three Mile Island would have remained little more than a minor inconvenience for Met Ed.

Part 2

To a casual visitor, the control room at TMI-2 can be an intimidating place, with messages coming from the loudspeaker of the plant's paging system; panel upon panel of red, green, amber, and white lights; and alarms that sound or flash warnings many times each hour. Reactor operators are trained how to respond and to respond quickly in emergencies. Initial actions are ingrained, almost automatic and unthinking.

The burden of dealing with the early, crucial stages of the accident at Three Mile Island fell to four men -- William Zewe, shift supervisor in charge of both TMI-l and TMI-2; Fred Scheimann, shift foreman for TMI-2; and two control room operators, Edward Frederick and Craig Faust. Each had been trained for his job by Met Ed and Babcock & Wilcox, the company that supplied the TMI Unit 2 reactor and nuclear steam system; each was licensed by the Nuclear Regulatory Commission; each was a product of his training -- training that did not adequately prepare them to cope with the accident at TMI-2. Indeed, their training was partly responsible for escalating what should have been a minor event into a potentially devastating accident.

Frederick and Faust were in the control room when the first alarm sounded, followed by a cascade of alarms that numbered 100 within minutes. The operators reacted quickly as trained to counter the turbine trip and reactor scram. Later Faust would recall for the Commission his reaction to the incessant alarms: "I would have liked to thrown away the alarm panel. It was'nt’t giving us any useful information." Zewe, working in a small, glass-enclosed office behind the operators, alerted the TMI-l control room of the TMI-2 scram and called his shift foreman back to the control room.

Scheimann had been overseeing maintenance on the plant's Number 7 polisher - - one of the machines that remove dissolved minerals from the feedwater system. His crew was using a mixture of air and water to break up resin that had clogged a resin transfer line. Later investigation would reveal that a faulty valve in one of the polishers allowed some water to leak into the air-controlled system that opens and closes the polishers' valves and may have been a factor in their sudden closure just before the accident began. This malfunction probably triggered the initial pump trip that led to the accident. The same problem of water leaking into the polishers' valve control system had occurred at least twice before at TMI-2. Had Met Ed corrected the earlier polisher problem, the March 28 sequence of events way never have begun.

Part 3

With the PORV stuck open and heat being removed by the steam generators, the pressure and temperature of the reactor coolant system dropped. The water level also fell in the pressurizer. Thirteen seconds into the accident, the operators turned on a pump to add water to the system. This was done because the water in the system was shrinking as it cooled. Thus more water was needed to fill the system. Forty-eight seconds into the incident, while pressure continued falling, the water level in the pressurizer began to rise again. The reason, at this point, was that the amount of water being pumped into the system was greater than that being lost through the PORV.

About a minute and 45 seconds into the incident, because their emergency water lines were blocked, the steam generators boiled dry. After the steam generators boiled dry, the reactor coolant heated up again, expanded, and this helped send the pressurizer level up further.

Two minutes into the incident, with the pressurizer level still rising, pressure in the reactor coolant system dropped sharply. Automatically, two large pumps began pouring about 1,000 gallons a minute into the system. The pumps, called high pressure injection (HPI) pumps, are part of the reactor's emergency core cooling system. The level of water in the pressurizer continued to rise, and the operators, conditioned to maintain a certain level in the pressurizer, took this to mean that the system had plenty of water in it. However, the pressure of reactor coolant system water was falling, and its temperature became constant.

About 2 1/2 minutes after the HPI pumps began working, Frederick shut one down and reduced the flow of the second to less than 100 gallons per minute. The falling pressure, coupled with a constant reactor coolant temperature after HPI came on, should have clearly alerted the operators that TMI-2 had suffered a LOCA, and safety required they maintain high pressure injection. "The rapidly increasing pressurizer level at the onset of the accident led me to believe that the high pressure injection was excessive, and that we were soon going to have a solid system," Frederick later told the Commission.

A solid system is one in which the entire reactor and its cooling system, including the pressurizer, are filled with water. The operators had been taught to keep the system from "going solid" - -a condition that would make controlling the pressure within the reactor coolant system more difficult and that might damage the system. The operators followed this line of reasoning, oblivious for over 4 hours to a far greater threat -- that the loss of water from the system could result in uncovering the core.

The saturation point was reached 5 1/2 minutes into the accident. Steam bubbles began forming in the reactor coolant system, displacing the coolant water in the reactor itself. The displaced water moved into the pressurizer, sending its level still higher. This continued to suggest to the operators that there was plenty of water in the system. They did not realize that water was actually flashing into steam in the reactor, and with more water leaving the system than being added, the core was on its way to being uncovered. And so the operators began draining off the reactor's cooling water through piping called the let-down system.

Eight minutes into the accident, someone -- just who is a matter of dispute -- discovered that no emergency feedwater was reaching the steam generators. Operator Faust scanned the lights on the control panel that indicate whether the emergency feedwater valves are open or closed. He first checked a set of emergency feedwater valves designed to open after the pumps reach full speed; they were open. Next he checked a second pair of emergency feedwater valves, called the "twelve-valves," which are always supposed to be open, except during a specific test of the emergency feedwater pumps. The two "twelve-valves" were closed. Faust opened them and water rushed into the steam generators.

The two "twelve-valves were known to have been closed 2 days earlier, on March 26, as part of a routine test of the emergency feedwater pumps. A Commission investigation has not identified a specific reason as to why the valves were closed at 8 minutes into the accident. The most likely explanations are: the valves were never reopened after the March 26 test; or the valves were reopened and the control room operators mistakenly closed the valves during the very first part of the accident; or the valves were closed mistakenly from control points outside the control room after the test. The loss of emergency feedwater for 8 minutes had no significant effect on the outcome of the accident. But it did add to the confusion that distracted the operators as they sought to understand the cause of their primary problem.

Throughout the first 2 hours of the accident, the operators ignored or failed to recognize the significance of several things that should have warned them that they had an open PORV and a loss of coolant accident. One was the high temperatures at the drain pipe that led from the PORV to the reactor coolant drain tank. One emergency procedure states that a pipe temperature of 2000F indicates an open PORV. Another states that when the drain pipe temperature reaches 1300F, the block valve beneath it should be closed. But the operators testified that the pipe temperature normally registered high because either the PORV or some other valve was leaking slightly. "I have seen, in reviewing logs since the accident, approximately 198 degrees," Zewe told the Commission. "But I can remember instances before . . . just over 200 degrees." So Zewe and his crew dismissed the significance of the temperature readings, which Zewe recalled as being in the 2300F range. Recorded data show the range reached 2850F. Zewe told the Commission that he regarded the high temperatures on the drain pipe as residual heat: "[K]nowing that the relief valve had lifted, the downstream temperature I would expect to be high and that it would take some time for the pipe to cool down below the 200-degree set point."

Part 4

At 4:11 am., an alarm signaled high water in the containment building's sump, a clear indication of a leak or break in the system. The water, mixed with steam, had come from the open PORV, first falling to the drain tank on the containment building floor and finally filling the tank and flowing into the sump. At 4:15 a.m., a rupture disc on the drain tank burst as pressure in the tank rose. This sent more slightly radioactive water onto the floor and into the sump. From the sump it was pumped to a tank in the nearby auxiliary building.

Five minutes later, at 4:20 a.m., instruments measuring the neutrons inside the core showed a count higher than normal, another indication - - unrecognized by the operators -- that steam bubbles were present in the core and forcing cooling water away from the fuel rods. During this time, the temperature and pressure inside the containment building rose rapidly from the heat and steam escaping via the PORV and drain tank. The operators turned on the cooling equipment and fans inside the containment building. The fact that they failed to realize that these conditions resulted from a LOCA indicates a severe deficiency in their training to identify the symptoms of such an accident.

About this time, Edward Frederick took a call from the auxiliary building. He was told an instrument there indicated more than 6 feet of water in the containment building sump. Frederick queried the control room computer and got the same answer. Frederick recommended shutting off the two sump pumps in the containment building. He did not know where the water was coming from and did not want to pump water of unknown origin, which might be radioactive, outside the containment building. Both sump pumps were stopped about 4:39 a.m. Before they were, however, as much as 8,000 gallons of slightly radioactive water may have been pumped into the auxiliary building. Only 39 minutes had passed since the start of the accident.

Part 5

George Kunder, superintendent of technical support at TMI-2, arrived at the Island about 4:45 a.m., summoned by telephone. Kunder was duty officer that day, and he had been told TMI-2 had had a turbine trip and reactor scram. What he found upon his arrival was not what he expected. "I felt we were experiencing a very unusual situation, because I had never seen pressurizer level go high and peg in the high range, and at the same time, pressure being low," he told the Commission. "They have always performed consistently." Kunder's view was shared by the control room crew. They later described the accident as a combination of events they had never experienced, either in operating the plant or in their training simulations.

Shortly after 5:00 a.m., TMI-2's four reactor coolant pumps began vibrating severely. This resulted from pumping steam as well as water, and it was another indication that went unrecognized that the reactor's water was boiling into steam. The operators feared the violent shaking might damage the pumps -- which force water to circulate through the core -- or the coolant piping.

Zewe and his operators followed their training. At 5:14 a.m., two of the pumps were shut down. Twenty-seven minutes later, operators turned off the two remaining pumps, stopping the forced flow of cooling water through the core.

There was already evidence by approximately 6:00 a.m. that at least a few of the reactor's fuel rod claddings had ruptured from high gas pressures inside them, allowing some of the radioactive gases within the rods to escape into the coolant water. The early warning came from radiation alarms inside the containment building. With coolant continuing to stream out the open PORV and little water being added, the top of the core became uncovered and heated to the point where the zirconium alloy of the fuel rod cladding reacted with steam to produce hydrogen. Some of this hydrogen escaped into the containment building through the open PORV and drain tank; some of it remained within the reactor. This hydrogen, and possibly hydrogen produced later in the day, caused the explosion in the containment building on Wednesday afternoon and formed the gas bubble that produced such great concern a few days later.

Other TMI officials now were arriving in the TMI-2 control room. They included Richard Dubiel, a health physicist who served as supervisor of radiation protection and chemistry; Joseph Logan, superintendent of TMI-2; and Michael Ross, supervisor of operations for TMI-l.

Shortly after 6:00 a .m., George Kunder participated in a telephone conference call with John Herbein, Met Ed's vice president for generation; Gary Miller, TMI station manager and Met Ed's senior executive stationed at the nuclear facility; and Leland Rogers, the Babcock & Wilcox site representative at TMI. The four men discussed the situation at the plant. In his deposition, Rogers recalled a significant question he posed during that call: He asked if the block valve between the pressurizer and the PORV, a backup valve that could be closed if the PORV stuck open, had been shut.
QUESTION: What was the response?

ROGERS: George's immediate response was, "I don't know, and he had someone standing next to the shift supervisor over back of the control room and sent the guy to find out if the valve block was shut.

QUESTION: You heard him give these instructions?

ROGERS: Yes, and very shortly I heard the answer come back from the other person to George, and he said, "Yes, the block valve was shut. . . "

The operators shut the block valve at 6:22 a.m., 2 hours and 22 minutes after the PORV had opened.

It remains, however, an open question whether Rogers or someone else was responsible for the valve being closed. Edward Frederick testified that the valve was closed at the suggestion of a shift supervisor coming onto the next shift; but Frederick has also testified that the valve was closed because he and his fellow operators could think of nothing else to do to bring the reactor back under control.

In any event, the loss of coolant was stopped, and pressure began to rise, but the damage continued. Evidence now indicates the water in the reactor was below the top of the core at 6:15 a.m. Yet for some unexplained reason, high pressure injection to replace the water lost through the PORV and let-down system was not initiated for almost another hour. Before that occurred, Kunder, Dubiel, and their colleagues would realize they faced a serious emergency at TMI-2.

In the 2 hours after the turbine trip, periodic alarms warned of low-level radiation within the unoccupied containment building. After 6:00 a.m., the radiation readings markedly increased. About 6:30 a.m., a radiation technician began surveying the TMI-2 auxiliary building, using a portable detector -- a task that took about 20 minutes. He reported rapidly increasing levels of radiation, up to one rem per hour. During this period, monitors in the containment and auxiliary buildings showed rising radiation levels. By 6:48 a.m., high radiation levels existed in several areas of the plant, and evidence indicates as much as two-thirds of the 12-foot high core stood uncovered at this time. Analyses and calculations made after the accident indicate temperatures as high as 3,500F to 4,000F degrees or more in parts of the core existed during its maximum uncovery. At 6:54 a.m., the operators turned on one of the reactor coolant pumps, but shut it down 19 minutes later because of high vibrations. More radiation alarms went off. Shortly before 7:00 a.m., Kunder and Zewe declared a site emergency, required by TMI's emergency plan whenever some event threatens "an uncontrolled release of radioactivity to the immediate environment."

Gary Miller, TMI station manager, arrived at the TMI-2 control room a few minutes after 7:00 a.m. Radiation levels were increasing throughout the plant. Miller had first learned of the turbine trip and reactor scram within minutes after they occurred. He had several telephone conversations with people at the site, including the 6:00 a.m. conference call. When he reached Three Mile Island, Miller found that a site emergency existed. He immediately assumed command as emergency director and formed a team of senior employees to aid him in controlling the accident and in implementing TMI-2's emergency plan.

Miller told Michael Ross to supervise operator activities in the TMI-2 control room. Richard Dubiel directed radiation activities, including monitoring on- and off-site. Joseph Logan was charged with ensuring that all required procedures and plans were reviewed and followed. George Kunder took over technical support and communications. Daniel Shovlin, TMI's maintenance superintendent, directed emergency maintenance. B&W's Leland Rogers was asked to provide technical assistance and serve as liaison with his home office. Miller gave James Seelinger, superintendent of TMI-l, charge of the emergency control station set up in the TMI-l control room. Under TMI's emergency plan, the control room of the unit not involved in an accident becomes the emergency control station. On March 28, TMI-l was in the process of starting again after being shut down for refueling of its reactor.

TMI personnel were already following the emergency plan, telephoning state authorities about the site emergency. The Pennsylvania Emergency Management Agency (PEMA) was asked to notify the Bureau of Radiation Protection (BRP), part of Pennsylvania’s Department of Environmental Resources. The bureau in turn telephoned Kevin Molloy, director of the Dauphin County Office of Emergency Preparedness. Dauphin County includes Harrisburg and Three Mile Island. Other nearby counties and the State Police were alerted.

Met Ed alerted the U.S. Department of Energy's Radiological Assistance Plan office at Brookhaven National Laboratory. But notifying the Nuclear Regulatory Commission's Region I office in King of Prussia, Pennsylvania, took longer. The initial phone call reached an answering service, which tried to telephone the NRC duty officer and the region's deputy director at their homes. Both were en route to work.

By the time the NRC learned of the accident -- when its Region I office opened at 7:45 a.m. -- Miller had escalated the site emergency at Three Mile Island to a general emergency. Shortly after 7:15 a.m., emergency workers had to evacuate the TMI-2 auxiliary building. William Dornsife, a nuclear engineer with the Pennsylvania Bureau of Radiation Protection, was on the telephone to the TMI-2 control room at the time. He heard the evacuation ordered over the plants paging system. "And I said to myself, 'this is the biggie,' " Dornsife recalled in his deposition.

At 7:20 a.m., an alarm indicated that the radiation dome monitor high in the containment building was reading 8 rems per hour. The monitor is shielded by lead. TMI’s shielding is designed to cut the radioactivity reaching the monitor by 100 times Thus, those in the control room interpreted the monitor's alarm as meaning that the radiation present in the containment building at the time was about 800 rems per hour. Almost simultaneously, the operators finally turned on the high pressure injection pumps, once again dumping water into the reactor, but this intense flow was kept on for only 18 minutes. Other radiation alarms sounded in the control room. Gary Miller declared a general emergency at 7:24 a.m. By definition at Three Mile Island, a general emergency is an "incident which has the potential for serious radiological consequences to the health and safety of the general public.

As part of TMI's emergency plan, state authorities were again notified and teams were sent to monitor radiation on the Island and ashore. The first team, designated Alpha and consisting of two radiation technicians, was sent to the west side of the Island, the downwind direction at the time. Another two-man team, designated Charlie, left for Goldsboro, a community of some 600 persons on the west bank of the Susquehanna River across from Three Mile Island. Meanwhile, a team sent into the auxiliary building reported increasing radiation levels and the building's basement partly flooded with water. At 7:48 a.m., radiation team Alpha reported radiation levels along the Island's west shoreline were less than one millirem per hour. Minutes later, another radiation team reported similar readings at the Island's north gate and along Route 441, which runs parallel to the Susquehanna's eastern shore.

Part 6

Nearly 4 hours after the accident began, the containment building automatically isolated. Isolation is intended to help prevent radioactive material released by an accident from escaping into the environment. The building is not totally closed off. Pipes carrying coolant run between the containment and auxiliary buildings. These pipes close off when the containment building isolates, but the operators can open them. This occurred at TMI-2 and radioactive water flowed through these pipes even during isolation. Some of this piping leaked radioactive material into the auxiliary building, some of which escaped from there into the atmosphere outside.

In September 1975, the NRC instituted its Standard Review Plan, which included new criteria for isolation. The plan listed three conditions -- increased pressure, rising radiation levels, and emergency core cooling system activation -- and required that containment buildings isolate on any two of the three. However, the plan was not applied to nuclear plants that had already received their construction permits. TMI-2 had, so it was "grandfathered" and not required to meet the Standard Review Plan, although the plant had yet to receive its operating license.

In the TMI-2 design, isolation occurred only when increasing pressure in the containment building reached a certain point, nominally 4 pounds per square inch. Radiation releases alone, no matter how intense, would not initiate isolation, nor would ECCS activation.

Although large amounts of steam entered the containment building early in the TMI-2 accident through the open PORV, the operators had kept pressure there low by using the building's cooling and ventilation system. But the failure to isolate early made little difference in the TMI-2 accident. Some of the radioactivity ultimately released into the atmosphere occurred after isolation from leaks in the let-down system that continued to carry radioactive water out of the containment building into the auxiliary building.

At 8:26 a.m., the operators once again turned on the ECCS's high pressure injection pumps and maintained a relatively high rate of flow. The core was still uncovered at this time and evidence indicates it took until about 10:30 a.m. for the HPI pumps to fully cover the core again.

By 7:50 a.m., NRC Region I officials had established direct telephone contact with the TMI-2 control room. Ten minutes later, Region I activated its Incident Response Center at King of Prussia, opened a direct telephone line to the Emergency Control Station in the TMI-l control room, and notified NRC staff headquarters in Bethesda, Maryland. Region I officials gathered what information they could and relayed it to NRC headquarters, which had activated its own Incident Response Center. Region I dispatched two teams of inspectors to Three Mile Island; the first left at about 8:45 a.m., the second a few minutes later.

Around 8:00 a.m., it was clear to Gary Miller that the TMI-2 reactor had suffered some fuel damage. The radiation levels told him that. Yet Miller would testify to the Commission: ". . . I don't believe in my mind I really believed the core had been totally uncovered, or uncovered to a substantial degree at that time."

Off the Island, radiation readings continued to be encouragingly low. Survey team Charlie reported no detectable radiation in Goldsboro. Miller and several aides concluded about 8:30 a.m. that the emergency plan was being properly implemented.

Part 9

At Three Mile Island, the control room was crowded with operators and supervisors trying to bring the plant under control. They had failed in efforts to establish natural circulation cooling. This essentially means setting up a flow of water, without mechanical assistance, by heating water in the core and cooling it in the steam generators. This effort failed because the reactor coolant system was not filled with water and a gas bubble forming in the top of the reactor blocked this flow of water. At 11:38 a.m., operators began to decrease pressure in the reactor system. The pressurizer block valve was opened and high pressure injection cut sharply. This resulted again in a loss of coolant and an uncovering of the core. The depressurization attempt ended at 3:08 p.m. The amount and duration of core uncovery during this period remains unknown.

About noon, three employees entered the auxiliary building and found radiation levels ranging from 50 millirems to 1,000 rems (one million millirems) an hour. Each of the three workers received an 800-millirem dose during the entry. At 12:45 pm., the Pennsylvania State Police closed Route 441 to traffic near Three Mile Island at the request of the state's Bureau of Radiation Protection. An hour later, the U.S. Department of Energy team began its first helicopter flight to monitor radiation levels. And at 1:50 p.m., a noise penetrated the TMI-2 control room; "a thud," as Gary Miller later characterized it.

That thud was the sound of a hydrogen explosion inside the containment building. It was heard in the control room; its force of 28 pounds per square inch was recorded on a computer strip chart there, which Met Ed's Michael Ross examined within a minute or two. Yet Ross and others failed to realize the significance of the event. Not until late Thursday was that sudden and brief rise in pressure recognized as an explosion of hydrogen gas released from the reactor. The noise, said B&W's Leland Rogers in his deposition, was dismissed at the time as the slamming of a ventilation damper. And the pressure spike on the strip chart, Ross explained to the Commission, "we kind of wrote it off . . . [as] possibly instrument malfunction.

Miller, Herbein, and Kunder left for Harrisburg soon afterwards for a 2:30 p.m. briefing with Lieutenant Governor Scranton on the events at Three Mile Island. At 2:27 p.m., radiation readings in Middletown ranged from 1 to 2 millirems per hour.

A Primer on Nuclear Safety: 1.4.1 Complexity and Three Mile Island

1.4.1 Complexity and Three Mile Island
The Three Mile Island accident was the primary example of what concerned advocates of the probabilistic approach to nuclear safety. A series of improbable events, lead to a partial meltdown of core of the Three Mile Island Unite 2 reactor. The background of these events certainly reflected attitudes in both the NRC and among reactor operators that failed to take nuclear safety concerns with sufficient seriousness. This is evident in The Report of the Presidential Commission on the Accident at Three Mile Island which paints a damning picture of the safety problems at Three Mile Island and the relative indifference of the NRC, the reactor's manufacturer Babcox & Wilcox (B&W) and its operator. The report looks at the problems that the operators of TMI Unit 2 faced on March 28, 1979 and concluded that the operators have been overwealmed by problems which could and should have been foreseen by the reactor's manufacturer, the control room architect, the NRC, and the reactor's operator.   

The Commission Report noted:
5. TMI management and engineering personnel also had
difficulty in analyzing events. Even after supervisory personnel
took charge, significant delays occurred before core damage was
fully recognized, and stable cooling of the core was achieved.
(Translation: The TMI staff did not have the slightest idea what was happening.)

6. Some of the key TMI-2 operating and emergency procedures
in use on March 28 were inadequate, including the procedures for a
LOCA [Loss of Coolant Accident] and for pressurizer operation. Deficiencies in these
procedures could cause operator confusion or incorrect action.
(The were rooted in the plans for dealing with the accident. The staff was confussed by the bad plans they were expected to follow.)

7. Several earlier warnings that operators needed clear instructions for dealing with events like those during the TMI accident had been disregarded by Babcock & Wilcox (B&W) and the Nuclear Regulatory Commission (NRC).
(OK lets take the TMI Staff of the Hook, because the NRC and B&W had been warned about the problems, and ignored the warnings.)
a. In September 1977, an incident occured at the Davis-Besse plant, also equipped with a B&W reactor. During that incident, a PORV stuck open and pressurizer level increased, while
pressure fell. Although there were no serious consequences of that incident, operators had improperly interfered with the HPI, apparently relying on rising pressurizer level. The Davis-Besse plant had been operating at only 9 percent power and the PORV block valve was closed approximately 20 minutes after the PORV stuck open.  That incident was investigated by both B&W and the NRC, but no information calling attention to the correct operator actions was provided to utilities prior to the TMI accident. A B&W engineer had stated in an internal B&W memorandum written more than a year before the TMI accident that if the Davis-Besse event had occurred in a reactor operating at full power, "it is quite possible, perhaps
probable, that core uncovery and possible fuel damage would have occurred."
(There was a dress rehearsal for the Three Mile Island incident at the Davis-Besse nuclear facility a year and a half before the TMI accident and the NRC & B&W knew all about it, but did not warn reactor operators about the problems uncovered.)
b. An NRC official in January 1978 pointed out the likelihood for erroneous operator action in a TMI-type incident.  The NRC did not notify utilities prior to the accident.
(The NRC staff knew that accident management procedures were dangerously flawed but the NRC did not take actions to bring about changes.)
c. A Tennesse Valley Authority (TVA) engineer analyzed the problem of rising pressurizer level and falling pressure more than a year before the accident. His analysis was provided to B&W,
NRC, and the Advisory Committee on Reactor Safeguards. Again no notification was given to utilities prior to the accident.
(Yet another warning had been received by the NRC and B&W with no action taken.)
8. The control room was not adequately designed with the management of an accident in mind. (See also finding G.8.e.) For example:
a. Burns and Roe, the TMI-2 architect-engineer, had never systematically evaluated control room design in the context a serious accident to see how well it would serve in emergency.
(The design of the TMI control room made accident management more difficult. The architects did not consider accident management in control room design.)
b. The information was presented in a manner which could confuse operators:
(i) Over 100 alarms went off in the early stages of the accident with no way of suppressing
the unimportant ones and identifying the important ones. The danger of having too many alarms was recognized by Burns and Roe during the design stage, but the problem was never resolved.
(No wonder the operators were confused during the early stages of the accident with all of those alarms going off. The Architects knew this was going to be a problem, but did not fix it.)

(ii) The arrangement of controls and indicators was not well thought out.  Some key indicators relevant to the accident were on the back of the control panel.
(What a mess. No one could expect frightened, poorly trained operators who lacked adequate procedural guidance and who were confronted with this poorly designed and confusing control panel to manage this accident.)

(iii) Several instruments went off-scale during the course of the accident, depriving the
operators of highly significant diagnostic information. These instruments were not designed
to follow the course of an accident.
(The instrumentation of the reactor was not designed with the possibility of accidents in mind. There failure to provide useful information during the accident was but another evidence that the NRC and B&W were not seriously considering accident management in reactor design.)
(iv) The computer printer registering alarms was running more than 2-k hours behind the events and at one point jammed, thereby losing valuable
information.
(The information system was not designed to provide information during an accident and broke down.)
c. After an April 1978 incident, a TMI-2 control room operator complained to his superiors about problems with the control room. No corrective action was taken by the utility.
(The TMI operators had been warned about the problems with the control room and did not do anything to rectify the problem.)

The Presidential Commission report is serious reading for anyone who is interested in the history of reactor safety.  The emergence of the large light water civilian power reactor posed significant challenges for nuclear safety.  Debate over nuclear safety issues had rocked the nuclear industry during the late 1960's and early 1970's.  AEC reactor research czar Milton Shaw, with the undoubted backing of Admiral Hyman Rickover, and powerful Congressman Chet Hollifeld had insisted that light water reactors represented a mature technology,   Advocates of nuclear safety concerns including Alvin Weinberg were concerned that the complexity of power reactors was creating new and significant safety problems.  This concern was to be justified by the Three Mile Island incident. Although Dixie Lee Ray had out manipulated Milton Shaw at the AEC  6 years previously, Shaw's attitude toward nuclear safety, was behind the problems which the Presidential Commission had documented.  

Morning thoughts, Leukemia and German Reactors

Lee Progress

On Thursday, Duke Energy submitted a licensing application for the Lee Nuclear Station in Cherokee County, North Carolina. This must have been a moment of great satisfaction to Ruth of We Support Lee, Nuclear Australia has already extended its congratulations and I join them in the sentiment.

Leukemia and reactors

There is a considerable gap between the the known causes of leukemia and the causes of cancer clusters in a given population. A recent German report found that between 1980 and 2003, 37 children living in the vicinity of 16 reactors contracted leukemia. The report states that for the subject population, 17 cases would have been expected. More information would have been helpful. For example, news releases do not mention patterns associated with individual reactors. It is very unlikely that the cases were distributed between all reactors evenly, or that they were distributed evenly through time. I say this because it is known that a leukemia cluster occurred in the North German community of Elbmarsch between 1990 and 1996. All nine of the children involved lived within 4500 meters of the Kruemmel reactor. Five of the nine cases were reported within 18 months of each other in 1990-1991.

The other 4 were reported in 1995-1996. The first six cases could be further localized to about 20% of a 5 Km ratdius from the plant. Five more cases were reported in the same area between 1999 and 2005. The same report stated that there were several other leukemia clusters associated with reactors in Europe. However, a comparative study of the area around the Savannah River Reactor operation, and the Kruemmel revealed that childhood leukemia case levels were not elevated in the Savannah River area. Since several releases of radioactive tritium were known to have occurred from the Savannah River site, and those releases exceed those from the Kruemmel site by several orders of magnitude, it is unlikely that releases of tritium played a role in the Kruemmel cluster.

Radiation monitoring in at the Kruemmel reactor and in the surrounding area have not detected releases of radioactive material from the reactor. However, reports (for example, here) indicate the presence of 238Pu, 239,240Pu, 241Am, and 244Cm in homes in the Elbmarsch community.

There have been reported leaks of coolant water from the Kruemmel facility, but this could hardly explain the presence of transuranium elements in Elbmarsch homes. No transport vector between the Kruemmel reactor has been found, or as far as I can tell, even suggested. The transuranium element could have come from fall out from nuclear tests, or Chernobyl fallout. But this is deemed unlikely. The Elbmarsch leukemia cluster has been the subject of extensive and ongoing study. The Kruemmel facility has also been the subject of intensive study and on going monitoring. To date no source of environmental transport of reactor byproducts inside the reactor or from within the facility has been found.

Studies of an association between childhood leukemia and the proximity of reactors have been inconclusive. One 1991 study of 107 counties near 62 nuclear facilities by the American National Cancer Institute found that the childhood leukemia rate for the reported areas dropped slightly after the reactors started operating. Another report of the same study indicated that one childhood Leukemia cluster was associated with the Millstone Power Plant located in New London, Connecticut. Three of the studied facilities had significantly fewer leukemia cases than were expected. Windham County, Vermont, where the Vermont Yankee reactor is located was reported to have only 9% of expected childhood leukemia cases.

Repeated studies failed to uncover an association between The Three Mile Island accident and childhood leukemia (see here , and here. Even more remarkable, studies have failed to uncover a relationship between exposure to radiation from Chernobyl and childhood leukemia (see here, and here). In the latter study, "Childhood leukaemia in Belarus, Russia, and Ukraine following the Chernobyl power station accident: results from an international collaborative population-based case–control study," S.Davis, RW Day, KJ Kopecky, MC Mahoney, PL McCarthy, AM Michalek, KB Moysich, LE Onstad, VF Stepanenko, PG Voillequé and others, "conclude that this study provides no convincing evidence of an increased risk of childhood leukaemia as a result of exposure to Chernobyl radiation, . ." They report some evidence that suggest effects of exposure to very low levels of radiation, as a causivetive factor in leukemia, but acknowledge that "prolonged exposure to very low radiation doses may increase leukaemia risk as much as or even more than acute exposure, but are inconsistent with published literature regarding the risk of leukaemia in relation to protracted radiation doses of the very low magnitude observed in this study."

It is clear then that radiation and isotope dangers from large scale and well known incidents like Three Mile Island and Chernobyl are not correlated with increased incidents of leukemia among exposed children. To date, leukemia clusters are far more likely to be associated with the operation of European than American reactors. They do not appear to be associated with large scale radiation releases. If they are caused by low level radiation increases in the environment, it should be expected that leukemia clusters should be associated with locations know to be at higher risk for radiation exposures. One such risk would be found in mountains, but altitude seems to play less a role in mountain related cancer clusters than the presence of tungsten.

It is clear then that there have been leukemia clusters associated with a few nuclear reactors. Some have been explained and others have not. Most reactors appear to be safe. Despite extensive German investigations the Elbmarsch cluster is still unexplained. If a defect in the design or operation of the Kruemmel reactor was responsible for the leukemia cluster, it would be very useful to know. Thus the Elbmarsch leukemia cluster has not been explained and leaves us with a mystery.