Friday, January 7, 2011

Further Jacobson objections to Consideration of Nuclear Power: Safety and Uranium

In his new paper on post carbon energy sources ("Providing all Global Energy with Wind, Water, and Solar Power, Part I: Technologies, Energy Resources, Quantities and Areas of Infrastructure, and Materials," Energy Policy in press), Mark Z. Jacobson refuses to consider nuclear power as a future energy source:
For several reasons we do not consider nuclear energy (conventional fission, breeder reactors, or fusion) as a long-term global energy source.
in previous posts, I have offered an extensive analysis of two major parts of of Jacobson's objections. By far the most serious objection is the claim that the spread of civilian nuclear power technology would lead to the development of nuclear weapons by states which currently lack them. This argument is speculative, and the evidence from actual instances of attempted our actual proliferation is that nations that lack a civilian nuclear power program are more likely to seek to acquire nuclear weapons, than nations which operate civilian power reactors.

A second Jacobson argument focused on CO2 emissions associated with civilian nuclear electrical generation. Jacobson's argument rested formally on two meta-analytic studies of nuclear associated emissions, but those studies in turn relied on a questionable source, and both appeared flawed by anti-nuclear biases. But Jacobson's argument appears to go beyond what could be asserted on the basis of his sources, and appears to rest on a previous Jacobson Paper in which he asserted a causal connection between the spread of civilian nuclear power technology and future nuclear wars every 30 years. Since the claimed connection between civilian nuclear power and nuclear weapons proliferation appears to have been falsified, the connection between the spread of civilian nuclear power and nuclear war appears to lack support. indeed it might be anticipated that nations which lack a civilian nuclear power program are more likely to engage in nuclear exchanges, than nations which possess civilian power reactors.

I mentioned one further Jacobson objection to nuclear power, the time required to construct nuclear power plants. Jacobson calmed,
The overall historic and present range of nuclear planning-to-operation times for new nuclear plants has been 11-19 years,
Yet the transformation of French electrical generation technology to 75% nuclear took place over a period of 19 years and involved the construction of no less than 54 reactors. Thus Jacobson once again offers assertions against which clear and powerful evidence support contradictory conclusions.

In addition to these objections Jacobson objected to consideration of nuclear power on the grounds of safety and the future nuclear fuel supply.
conventional nuclear fission relies on finite stores of uranium that a large-scale nuclear program with a “once through” fuel cycle would exhaust in roughly a century (e.g., Macfarlane and Miller, 2007; Adamantiades and Kessides, 2009). In addition, accidents at nuclear power plants have been either catastrophic (Chernobyl) or damaging (Three-Mile Island), and although the nuclear industry has improved the safety and performance of reactors, and has proposed new (but generally untested) “inherently” safe reactor designs (Piera, 2010; Penner et al., 2010; Adamantiades and Kessides, 2009; . . .
Since Jacobson passes over the whole safety issue with a relatively few words, I will deal with his assertions on nuclear safety briefly. First, nuclear power has proven itself to be by far the safest energy technology. Conventional Light Water Reactors have proven themselves to be extremely safe, with an unprecedented record of operation without a major accident since 1979. The only serious LWR accident failed to produce injuries or deaths, despite long standing, but unsuccessful efforts by nuclear opponents to argue that there were Three Mile Island accident casualties. This contention was rejected by a court decision. Thus, the safety of nuclear power has been established by thousands of years of Light Water Reactor operation without a single casualty producing reactor accident.

Jacobson's treatment of “inherently safe reactor" is very problematic. Jacobson asserts, although
the nuclear industry has . . . i proposed new (but generally untested) “inherently” safe reactor designs . . . there is no guarantee that the reactors will be designed, built and operated correctly.
In fact several “inherently safe reactor" have been tested. these include the Pebble Bed Reactor, the IFR prototype, the EBR II, and the Molten Salt Reactor prototype, the MSRE. These tests demonstrated that inherently safe reactors are possible, and can be built with proven technology. Thus we can point to reasonable assurance that inherently safe reactors will be in fact safe.

In the case of all three prototypes, inherent safety features were tested and performed as expected. In the case of the molten salt reactor, the stability and safety features are so inherent in the reactor concept, that an unsafe MSR design is highly unlikely. The inherent safety of the Molten Salt Reactor is a byproduct of the basic reactor concept. Further molten salt power generating reactors can be designed to produce power without any operator input. Hence operator errors would be impossible in normal operation situations. Hence Jacobson's claims about inherent nuclear safety are contradicted by reactor prototype safety experiments, and the basic nature of the inherently safe reactor concepts.

Next we turn to the Jacobson claim that
a large-scale nuclear program with a “once through” fuel cycle would exhaust [uranium supplies] in roughly a century
This contention is decisively refuted by a recent MIT report "The Future of the Nuclear Fuel Cycle," That report states,
There is no shortage of uranium resources that might constrain future commitments to build new nuclear plants for much of this century at least.
The benefits to resource extension and to waste management of limited recycling in LWRs using mixed oxide fuel as is being done in some countries are minimal.
Scientifically sound methods exist to manage spent nuclear fuel.
it is often recognized that long term, nuclear technology needs to shift from once through Light Water reactors, to more advanced uranium and thorium breeder reactors. Since the dawn of the nuclear age, reactor scientists have understood that the long range development of nuclear power would require breeder reactors. The possibility of using advance technology reactors to breed uranium and thorium has been frequently discussed. Jacobson rejects the possibility of nuclear breeding with a the simple claim that there is no proliferation proof nuclear power cycle. While this is true, as we have already noted a commitment to nuclear power generation appears to decrease rather than increase proliferation risks. Thus there is no clear evidence that nuclear breeding technology will actually lead to nuclear proliferation in practice. Jacobson relies entirely on speculative, untested and untestable arguments in making the claim that breeder reactors pose significant proliferation risks.

Jacobson also briefly reviews the use of thorium breeding as an alternative rout to sustainable nuclear power but ultimately rejects it:
A related proposal is to use thorium as a nuclear fuel, which is less likely to lead to nuclear weapons proliferation than the use of uranium, produces less long-lived radioactive waste, and greatly extends uranium resources (Macfarlane and Miller, 2007). However, thorium reactors require the same significant time lag between planning and operation as conventional uranium reactors and most likely longer because few developers and scientists have experience with constructing or running thorium reactors, As such, this technology will result in greater emissions from the background electric grid compared with WWS technologies, which have a shorter time lag. In addition, lifecycle emissions of carbon from a thorium reactor are on the same order as those from a uranium reactor. Further, thorium still produces radioactive waste containing 231Pa, which has a half-life of 32,760 years. It also produces 233U, which can be used in fission weapons, such as in one nuclear bomb core during the Operation Teapot nuclear tests in 1955. Weaponization, though, is made more difficult by the presence of 232U
once again we see that Jacobson relies on his business as usual, too much time argument, to justify the rejection of what would otherwise appear to be an attractive nuclear option. And once again Jacobson relies on a problematic argument. In the case of thorium, relatively small thorium breeding molten salt reactors (LFTRs) can be rapidly built in factories, and require significantly less on site work to for their completion. The LFTRF licensing process can be streamlined, if a goal of completing hundreds or even thousands of LFTRs in a short time is viewed as desirable. A small amount of Ps-231 is produced in thorium breeding, but it can simply left in the reactor core where it can be converted by the breeding process to U-232 or U-233. While it is true that U-233 is weaponizable, the one test of a U-233 containing device proved to be a failure. It would appear that American weapons designers rejected U-233 as a weapon material. As with proliferation risks associated with fast reactors, there is no strong evidence that possessing thorium breeding reactors actually increases the danger of nuclear proliferation beyond the risks associated with not possessing civilian nuclear power plants.

The global abundance of thorium, an untapped source of potential nuclear fuel, is such that thorium could supply all human energy needs for millions of years. Thorium fueled molten Salt Reactors are very safe, and the CO2 emissions associated with them would be far less than those associated with any renewable energy source. Liquid Fluoride Thorium Reactors can be operated to produce no long term transuranium waste, and to produce fission product wast that with reach background radiation levels within 300 years.

Thus once again it must be concluded that Mark Z. Jacobson excluded nuclear power as a future energy source without rational justification.


donb said...

Charles Barton commented:
...previous Jacobson Paper in which he (Jacobson) asserted a causal connection between the spread of civilian nuclear power technology and future nuclear wars every 30 years.

Nuclear weapons have been used only in one war, and they were used before civilian nuclear power plants existed. We are more than 50 years into the civilian nuclear power era. By Jacobson's reasoning, we should have had one nuclear war already, and be on the verge of a second.

We need to take his statement for what it is -- a gratuitous assertion made to bolster his own weak arguments.

Charles Barton said...

Don, What can I say, Jacobson has built his entire scheme on implausible speculations.

Andrew Jaremko said...


Thanks for your critiques of Jacobson's paper. I hope you've been able to publish them in the literature as well as here on the web; he needs to be taken to task for his incomplete analyses.

I tried the link to his paper in your previous post, but it's broken. Sleuthing around got me to the index page which seems to have the article. It's interesting that Stanford has left some of their directories open to a directory listing.

Anonymous said...

I don't get the whole quest for inherently safe reactors. LWRs have negative reactivity due to the coolant also being the moderator that keeps the chain reaction going. If something drastic happens the coolant will be lost and the chain reaction will stop. In fact the chain reaction will stop even without breaking primary circuit, the negative feedback is very powerful.

This is an inherent safety mechanism. It means LWRs cannot go Chernobyl. They can still damage themselves from fission product afterheat. This damage is limited to the plant. It is the difference between having 7% heat load or 10000% (the latter caused Chernobyl). The negative feedback prevents Chernobyl completely. It is physics.

I don't like it when people talk about gen4 as inherently safe because it suggests there is no inherent safety with current designs. As we can see above this is not correct. If we define inherently safe as being completely safe to the general public, then LWRs already do this.

Cheers, Cyril.

Alex877 said...

I am sure Rod Adams would appreciate those comments Cyril. Maybe he will pop up with a comment of his own.

Rod Adams said...

Charles - you're right. I like Cyrill's comment. LWR's may not be perfectly safe from the point of view of being immune to damage, but from the point of view of their neighbors, they are "safe enough" so that there is no real risk to anyone other than the plant owner and operators. Even that risk has proven to be quite manageable.

Charles Barton said...

Rod, i accept the safety of light water reactors, but LWR safety costs a good deal. It would be a mistake to not go for even safer reactors if they costed even less.

Anonymous said...

If any nation thinks it needs and wants nuclear weapons it is India. Even with their chronic lack of uranium and plutonium, India has not fielded a thorium weapon regardless of how much thorium reserves they have.

In fact, they have had a hard time convincing the world that they have even tested a U233 bomb since the claimed test did not register on near by seismographs.

Their proof was an aerial photo of a pile of sandbags where about a half dozen of those sandbags had been slightly displaced.


With all the time and money that India devotes to nuclear defense, making a workable bomb from U233 must be a very hard thing to do.


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