Charles E. Till's Account of the IFR Development Program

I am posting a copy of Charles E. Till's 1994 statement on the purpose of the IFR. There are several important statements which I would like to note before the interested reader passes on to the body of the text. Till claimed

The fast spectrum reactor provides the only avenue to control of the overall amounts of plutonium world wide that also fits naturally into electricity generation systems

This was not true, as Till must have known in 1994. A few months before Till made this statement, Uri Gat of ORNL, and J.R. Engel had presented a paper at another conference titled, Dismantled weapons fuel burning in molten salt reactors. This paper makes clear that burning plutonium in electricity generating molten salt thermal breeders is an alternative option to the use of fast reactors to manage the world's growing supply of plutonium. The potential for burning of Reactor Grade Plutonium in Molten Salt Breeder Reactors is clear in ORNL-TM-4613, "Molten-salt reactors for efficient nuclear fuel utilization without plutonium separation." This was not the only ORNL paper suggesting the MSBR option that Till chose to ignore. Research continues on the use of Molten Salt Reactors as nuclear waste burners at the Kurchatov Institute, Moscow, Russia, and at the University of Grenoble, France.

My reason for posting Till's statement is simple. IFR backers appear to be hiding quite a lot. Despite repeated suggestions that they collect and post primary IFR research documents in one internet site, as LFTR backers have, the simply point to the US DoE's Information Bridge, and seldom reference the primary research documents when they make their claims. Thus claims about IFR breeding ratios are not, as far as I can tell, backed up by Argonne research documents posted on the Information Bridge. Secondly, IFR technological discussions are closed to all but a selected inner circle. Members of the general public and most LFTR backers are excluded from those discussions. In contrast, anyone who cares too, can join the public discussions on Energy from Thorium, and IFR backers can participate in more restricted discussions. We openly discuss LFTRR developmental issues and members of the general public as well as IFR backers can participate in and read our discussions. IFR backers hide their developmental issues by closing discussions of technical problems from outsiders.

There are several issues which have to do with claims made by IFR backers. After I reviewed them recent IFR design documents on the Information Bridge, the claim that the IFR is ready to go does not hold water. The only recent design exercise has to do with the ABTR, which appears to be a very good design, but should be classified as a proof of concept prototype, or developmental prototype, rather than a commercial prototype. Further more, the ABTR is not intended to be a breeder, and would not support the breeding ratio that IFR backers claim, although with some core configurations it would support a positive breeding ratio. Other IFR documents on the Information Bridge that I looked at repeatedly made the statement that the IFR is a burner, not a breeder.

At the moment IFR backers appear to have a serious credibility problem:
1. There is no evidence on the Information Bridge (at least that I have been able to find) that backs up their claims about the IFR breeding in a high range.
2. The only recent prototype design on the energy bridge, suggests that the IFR is nor in a more mature development stage than the LFTR.

There is no credible evidence from the Information Bridge that would support the contention that the IFR can be developed more quickly or at a lower cost than the LFTR.

Further, IFR backers are admitting that over 10 times as many LFTRs can be started with available start up charges than IFRs. They are attempting to make the case that while the LFTR would possess superior scaleability, it cannot breed. There is no documented research to back up this charge that I have seen. The other claim that some IFR backers make is that the IFR possesses superior fuel doubling time. Yet the most recent IFR from Argonne is a burner, not a breeder, and a burner which at best can only breed at a rate similar than ORNL MSBR designs from the early 1970's. Recent French code based research confirmed the ORNL contention that thorium breeding molten salt reactors, with a RGP start up charge can breed.

Thus IFR backers need to clearly demonstrate from research documents that
* The IFR development has reached a more mature stage than the LFTR
* Mature IFR design plans exist that support high range breeding
* The IFR can equal the LFTR's scaleability potential while at the same time offering superior breeding potential
* The cost of IFR development will be lower than the cost of LFTR development
* The cost of large scale IFR deployment will not be higher than the cost of large scale LFTR deployment
* Large scale IFR deployment can occur in a significantly shorter time than large scale LFTR deployment, given equivalent levels of investment

ENERGY OVER THE CENTURIES: THE IFR OPTIONS
by Charles E. Till Associate Laboratory Director
Engineering Research
Argonne National Laboratory
9700 South Cass Avenue Argonne, Illinois 60439
The Plutonium Surplus Applications and Options Conference, The Royal Institute of International Affairs, January 24-25, 1994, London England.

ENERGY OVER THE CENTURIES: THE IFR OPTION

Abstract

The fast spectrum reactor provides the only avenue to control of the overall amounts of plutonium world wide that also fits naturally into electricity generation systems. Sufficient plutonium has now been produced, and is currently being produed, that the characteristic that this system possesses to burn plutonium rather than breed it should be the reference configuration for such reactors for a long time. Fuel reycle is the key and recycle with as little plutonium purification as possible is desirable. Such development is taking place within the Integral Fast Reactor program and is at the point of demonstration at engineering scale.

1 Introduction

It has long been recognized that plutonium benefits from the neutron spectrum of a fast reactor. In a fast spectrum the cross sections are at their most favorable; all isotopes of plutonium fission well, and further, all other capture products of uranium--the "minor actinides" fission efficiently as well. This is the path to the essentially infinite energy potential of uranium; use of all of the 238 U, less only the small losses in processing, in fact, one hundred to two hundred times the present utilization of uranium in thermal reactors. But even the impetus provided by needs for non-polluting energy sources, and growing sentiment in favor of recycle of all resources, has been insufficient to clear the way for fast reactors. In part this is precisely due to concerns about plutonium, and plutonium breeding, that fast reactors appear to add to. The facts may be quite different. I submit that they are. And I wish to give you my view of the facts, and what I think follows from them, underlining and stressing that they are my own thoughts only, and they certainly do not represent any official or organizational position, or initiative, either of my Laboratory of my Government.

The simple fact is that first, plutonium is produced in quantity every year by today's thermal reactors, approximately a thousand tons exist today and production continues at rate today of about 70 tons a year. Secondly, and the important subject of this meeting, many tens of tons of weapons plutonium are now also becoming available, for, it can be most devoutly hoped, alternative usages. My major thesis is that the very amounts and the availability of plutonium change markedly how the fast reactor should be viewed. Some of the considerations are the following:

1.1 MANAGING PLUTONIUM: The fast spectrum fissions plutonium, burning it, destroying it. This is worth underlining, for the thermal spectrum of our present reactors does not, or more correctly, it does not do it well. The thermal reactor--the LWR--destroys some plutonium, and alters the isotopic composition of the rest, as irradiation proceeds. But the fraGtion of the plutonium that is actually destroyed, before the isotopic composition has evolved to the point it is reactivity-worthless (again in the thermal spectrum) is not anything like unity. It is a few tens of percent at most.

The phrase "Managing Plutonium" is at the heart of the point I wish to make. "Managing Plutonium" can mean controlling its amount (as well as its _ nature) in a regime in which plutonium inventory can be reduced, maintained or increased, purely as a matter of energy policy. This is possible. But to accomplish this, the machinery to do so--the reactors and the accompanying processes--must be suited to the task in a way that present-day reactors are not.

Principally, they must be able to do one thing: They must be able to burn plutonium in the net, and without releasing plutonium from the system. Not burn some, and transform the isotopes of the rest, but to destroy plutonium, without plutonium leaving the system as "waste" that in turn must somehow be "managed."

It goes without saying that only fissioning accomplishes this, and the point really follows directly from the observation that only the fast spectrum fissions all plutonium isotopes effectively.

1.2 BURNING PLUTONIUM: The amounts of plutonium now being produced in thermal reactors, and in the weapons stocks, are large. The principal point here is that they are large on the scale or: future needs for energy production. And this, more than any other single thing, changes the perspective in which fast reactors should be viewed.

In the thinking of just a few decades ago, fast reactors were to come on quite quickly, before plutonium stocks, on the appropriate scale, were large. So breeding was important. But this did not happen. And the amount of
plutonium that has now built up is such that by the year 2010--a year ! take as the earliest that any appreciable amount of fast reactol' capacity could be in place--the world inventory of plutonium would fuel fully 200 GWe of fast
reactors.

The worlds current nuclear capacity is about 330 GWe. So as an example, if the plutonium output of all of these thermal reactors were fed to the 200 GWe of fast reactor capacity, and these fast reactors were configured as burners, a stable plutonium inventory, neither increasing or decreasing is possible. The fast reactors would have to be configured with a Conversion Ratio of about 0.67, a number that is perfectly possible.
There obviously are many scenarios, and many w_ys of looking at this, but for my purposes, this one simple example is sufficient.

The point is this: The worlds inventory of plutonium can be managed, in this way--possibly only in this way--forever. It could decreased or increased at will. There would no longer be anything inexorable about plutonium increase, or any unavoidable permanence in weapons plutonium stocks, as it seems there is at present day.

1.3 ENERGY IMPLICATIONS: The next point to look at is just how much managing plutonium in this way could benefit policies for energy production from the point of view both of environmentally benign production and of the magnitude of the energy producible. The magnitude must be sufficient to justify the expenditure of the necessary capital, financial, intellectual, and in these days, emotional, required to undertake the enterprise.

The environmental point hinges on the balance between the zero chemical emissions, on one hand, and the radiological safety on the other. The magnitudes are certainly pass the test. Simply the example quoted would give one quarter or so of the present world usage of electricity. Adjustment of the fast reactor conversion ratio would make more possible.
The points then are these:
a. Fast reactors should be burners, for the foreseeable future, perhaps through the 21 st Century.
b. The energy production possible from management of current plutonium stocks and current plutonium production rates is large, and sustainable.

1.4 GROWTH POTENTIAL: The size of the base of fast reactors in such a plutonium--stable regime of reactors--thermal and fast--is such that growth could take place, if required by energy demand, not limited by uranium resource availability, plutonium availability, or by physics-challenging breeding requirements.

1.5 DEMANDS ON FAST REACTOR CONCEPTS: The requirements placed on fast reactors differ from those previously envisioned.

a. Principally, in managing plutonium it becomes important that the reactors, and their processes for recycling their plutonium, do not themselves add to weapons concerns.

They must make regimes for managing plutonium easier, not harder; quite apart from their energy benefits.

b. Waste should not add to the problem, and in particular, the waste itself should not contain plutonium or other materials
that themselves require managing.
c. Safety must be demonstrable.
d. The economics have to be such that they encourage implementation--the energy value of the plutonium is one key, the avoided costs of the alternatives, another.

The Integral Fast Reactor Developments

The Integral Fast Reactor, or IFR, program has been underway since 1984. IFR development has been along lines that are compatible with fast reactor usage in a managed plutonium environment.
A reassessment of the requirements for nuclear fuel recycle, including safeguards and cost minimization, led to development of the concept, which is based on metal fuel and a high temperature, electrochemical recycle technology. The reactor concept does have excellent safety characteristics and a recycle technology which potentially, at least, appears to be economically attractive. The first bonus of this approach to closing the fuel cycle is that the recycle process is capable of essentially complete recovery of all transuranics. This simplifies waste handling. The second corollary bonus and the principal benefit for our purposes is that the system can accept any transuranic as fuel, and essentially no transuranics leave; the system is thus an ideal means of consuming actinides, whether the source is excess weapons plutonium, transuranics received from spent LWR fuel, scrap from weapons programs, or returns from other DOE programs. By simple fuel configuration changes, the system can go from a burner to a breakeven transuranic inventory, where the only feed is depleted or natural uranium. Further adjustments could yield excess IFR fuel (but still no separated plutonium) for a growing power economy.

3. The IFR Fuel Cycle The IFR fuel cycle principal steps are in the following:
1. Preparation of discharged fuel for processing.
2. Processing by eBectrorefining.
3. Vaporization of solvent metals and salts from electrorefiner products to yield a plutonium-rich U-Pu alloy and uranium
metal.
4. Injection casting to produce new fuel pins, which are sheathed in thin-wall, type HT-9 ferritic stainless steel cladding. The sheathed pins are called fuel elements.
5. Incorporation of fuel elements into fuel assemblies for return to the reactor.
All operations are carried out remotely.

The key characteristics of the process, from the point of view of Pu manageability--safeguardability--are attributable to the use of electrorefining for actinide separation and recovery, in place of more traditional solvent extraction methodology. The resultant fuel product--although excellent fast reactor fuel-- contains all the transuranics and significant amounts of fission products in addition to a uranium-plutonium mixture. This is inherent in the process, and cannot be significantly altered. The result is a plutonium-containing product that is mixed with uranium, contains Am and Np, and sufficient radioactive fission products to keep the product "self protecting," handleable only remotely. Not much different, in fact, for weapons purposes, from spent fuel, but fresh fuel to the IFR.

A pilot-plant-scale demonstration of the entire IFR fuel cycle, in conjunction with EBR-II and its refurbished Fuel Cycle Facility, is getting underway at the present time. Most of the process equipment systems have now been fabricated, tested, and are being installed in the Fuel Cycle Facility. The most important equipment, the electrorefiner, is in the final stage of qualification testing. The main hot cell of the Fuel Cycle Facility has been filled with argon and is going through the integrated acceptance testing. The Fuel Cycle Facility should be ready for plutonium operation in March anJ the irradiated fuel processing should start this summer.