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Major Energy and Environmental News and Commentary affecting the Nuclear Industry.

Saturday, September 18, 2010

All Things Nuclear Insights on Science and Security Fact, Fiction and Faith: The Endless Debate Over Reprocessing | by Ed Lyman


My testimony before the Reactor and Fuel Cycle Technology Subcommittee of the Blue Ribbon Commission on America’s Nuclear Future (the “BRC”) elicited a predictable and depressing reaction from certain corners of the blogosphere. I informed the Subcommittee that although UCS does not oppose nuclear energy per se, we do oppose reprocessing spent nuclear fuel because of the security, safety and proliferation risks that it poses. I then presented the Subcommittee with a summary of the rationale behind our position, complete with numerous technical references. The UCS position was in direct opposition to that of four of the six members of the panel I was on (representing AREVA, General Electric-Hitachi, Westinghouse and Energy Solutions), who all supported spent fuel reprocessing and “recycling” strategies of one sort or another.
My testimony appears to have given certain bloggers heartburn. Rod Adams of Atomic Insights saw fit to criticize my competence, my understanding of technology and my use of what he called “unsubstantiated statements and vague references.” Yet he was unable to actually point to anything specific in my testimony that he could contradict. Instead, he posted a video clip of my presentation and invited his loyal readers to defend the faith by “dissecting” my testimony.
I would be more than happy to engage Mr. Adams’ readers in a technical debate on these issues, so I thought, frankly, that this was a fine idea. However, two weeks later, it appears that Mr. Adams’ gambit has backfired. Out of twenty comments, only one actually professes any knowledge of any of the references that I cited. Most simply repeat unsubstantiated assertions themselves. Some claim that I must have misinterpreted the references but did not actually bother to look them up. Several are ad hominem attacks on me or UCS. A couple actually agree with some of the points I made. All in all, not a very impressive showing. In fact, I found only two statements that merit a response. Below, I respond to those statements.
Mr. Adams and his readers should rest assured that every statement I make is supported by direct references and transparent analysis. In the future, I’d appreciate that observers interested in a technical debate actually consult my written works and references before throwing darts.
There are three main points to my testimony.
1. Reprocessing spent nuclear fuel has only a marginal impact on the volume of high-level waste requiring disposal in a geologic repository, while significantly increasing the volume of other forms of nuclear waste also requiring secure disposal.

Some reprocessing advocates argue that the technology can reduce the volume of high-level nuclear waste requiring disposal in a geologic repository. On the Atomic Insights blog, Lars Jorgensen says that it is “easy” for any recycling system to significantly reduce waste volume.

However, reprocessing actually increases, not decreases, the total volume of long-lived nuclear waste that must be stored and eventually buried in a geologic repository  It only slightly reduces the volume of high-level nuclear waste that must be disposed of in a repository, as required by the Nuclear Waste Policy Act. At the same time, it significantly increases the volume of “greater-than-class-C” low-level waste, which cannot be legally disposed of in near-surface low-level waste facilities and would therefore need to be buried in a geologic repository as well. In addition, reprocessing increases the volume of low-level waste that must be disposed of in NRC-licensed near-surface facilities. Only one new low-level waste facility has been licensed in the United States in decades, and no policy (not to mention a repository) exists for disposal of GTCC LLW.
According to Argonne National Laboratory data cited by the Energy Department’s 2008 Global Nuclear Energy Draft Programmatic Environmental Impact Statement, compared to the once-through cycle, a fast-reactor-based reprocessing and recycle system would increase the total volume of radioactive waste by a factor of about seven. In particular, reprocessing would generate, in terms of volume,
  • Seven times as much Class A, B and C low-level waste (LLW)
  • 166 times as much greater-than-class-C LLW (over 8,000 cubic meters annually on average)
  • only 25% less high-level waste (HLW)
The last data point conflicts with public statements being made by AREVA, which continues to claim that “recycling reduces by 75% the volume of high-level waste that must be sent to a repository.” However, this assertion is not even supported by AREVA’s own data. According to a 2009 presentation to the Nuclear Waste Technical Review Board, Dorothy Davidson of AREVA indicated that the volume of reprocessing waste requiring geologic disposal (vitrified high-level waste and compacted hulls and end pieces) was 10 cubic feet per metric ton heavy metal of initial spent fuel reprocessed (10 ft3/MTHM). In the same presentation, Davidson claimed that this should be compared a spent fuel volume of 45 ft3/MTHM, so that reprocessing results in a more than four-fold decrease in waste volume.

However, this latter figure is incorrect. As Table S.3-1 shows, the volume of light-water reactor spent fuel is actually closer to 15.8 ft3/MTHM (0.45 m3/MTHM). Therefore, the HLW volume per MTHM according to AREVA’s own data is only about 37% less than the initial volume of spent fuel – a much less impressive reduction than the 75% cited by AREVA, and one much closer to the Argonne/DOE estimate. Apparently, this discrepancy stems from the fact that AREVA did not directly compare the volume of HLW to the volume of spent fuel, but compared the volume of HLW to the volume of the spent fuel waste disposal package that was originally considered for the Yucca Mountain repository, which had a significant amount of empty space. This is not an apples-to-apples comparison.

But in any event, heat load, not volume, is typically the limiting factor in a geologic repository. If plutonium and other transuranic elements such as americium are removed with very high separation factors, the heat load of the residual waste will be reduced. However, unless the actinides that are removed from the spent fuel are actually destroyed through fission in a reasonable period of time, they will have to be stored for an indefinite period (posing many of the same concerns as indefinite interim storage of spent fuel), and eventually will have to be disposed of in a repository. Yet as the discussion in the next section indicates, reprocessing and transuranic recycle systems are not capable of significantly reducing total actinide inventories in a reasonable period of time. 

2. Reprocessing and recycling spent nuclear fuel, whether in thermal or fast reactors, cannot effectively reduce the total quantity of hazardous radionuclides like plutonium and other transuranic elements that would require disposal in a repository.

Numerous studies have shown that fast reactor (FR) recycle systems are very slow and inefficient in actually fissioning transuranic elements, even if they operate in burner mode with very low conversion ratios. A recent study by the Electric Power Research Institute (EPRI) and Electricité de France (EdF) examined the impact of phasing in a fast reactor system operating in tandem with light-water reactors (LWRs) (35 percent FRs and 65 percent LWRs) and operating at a conversion ratio of 0.5, while keeping constant the total U.S. nuclear generating capacity. [1] The study found that the total inventory of plutonium and other transuranics would increase to over 1500 metric tons - roughly three times today’s inventory - and would remain essentially constant after that. Thus the system is simply not capable of reducing the total transuranic inventory, and the popular image that such a system can “burn up” nuclear waste is simply not accurate.

The EPRI study also compares the transuranic inventory in the system to the inventory that would accumulate in spent fuel if the U.S. continued with the once-through cycle. The analysis finds that the system would have to operate for 70 years just to reduce the total inventory of transuranics in the system by 50 percent relative to the once-through inventory. To reduce the inventory by 90 percent would require continuous operation for 632 years. Thus the system of reprocessing plants, fuel fabrication plants, fast reactors and associated facilities would have to operate over a period spanning many generations – and be rebuilt many times – before it could achieve a significant reduction in actinide inventory and a significant decrease in repository heat load compared to the once-through cycle. The paper concludes that “the analysis for the specific [recycling] scenario considered shows that it would take many decades, even centuries, for significant waste management benefits to materialize.” This is consistent with the one of the conclusions of the MIT study “The Future of the Nuclear Fuel Cycle,” released earlier this week – namely, that the choice of fuel cycle would make “little difference” in the total transuranic inventory in this century.

Proposals that require the essentially indefinite reprocessing and recycling of spent fuel do not provide a suitable foundation of nuclear waste management because they are inconsistent with the “intergenerational equity” principle. This principle, which underlies the rationale for a geologic repository for nuclear waste, includes the provisions that (1) those who generate the wastes should take responsibility, and provide the resources, for the management of these materials in a way which will not impose undue burdens on future generations; and (2) that a waste management strategy should not be based on a presumption of a stable societal structure for the indefinite future, nor of technological advance; rather it should aim at bequeathing a passively safe situation which places no reliance on active institutional controls.

A system that would require hundreds of years of costly and complex operations to achieve only a modest reduction in repository space requirements is not consistent with these principles. Some reprocessing advocates argue that nuclear materials that are in the fuel cycle – that is, in reactors, fuel fabrication plants, and above-ground storage facilities – need not be counted as wastes. This is only true, however, as long as the system is running. If it shuts down for any reason, these materials will require secure disposal. Thus our generation would be bequeathing to future generations the obligation of keeping the system going, without regard to cost or risk. This is clearly inconsistent with intergenerational equity.
3. Advanced reprocessing technologies do not significantly reduce nuclear proliferation and nuclear terrorism risks relative to current reprocessing technologies that produce separated plutonium.

Energy Secretary Chu has spoken of the proliferation risks associated with conventional reprocessing technology, as practiced in France and Japan, and has expressed confidence that the U.S. can develop alternatives that are “proliferation-resistant.” One of the goals of the Bush Administration’s Global Nuclear Energy Partnership program (GNEP) was also to develop so-called proliferation-resistant reprocessing technologies that did not produce “separated” plutonium.

However, a study conducted by the nuclear weapons labs reviewed the entire suite of technologies that were under study, including modified aqueous reprocessing and pyrometallurgical processing (“pyroprocessing”), with regard to their potential for reducing proliferation concerns. [2] The study found that the products of these processes, mixtures of plutonium and other actinides such as neptunium, americium and curium, are attractive for use in nuclear weapons or nuclear explosive devices. It concluded that there is no “silver bullet” technology that would eliminate the safeguards and security issues associated with reprocessing, and also that “none of the proposed flowsheets examined to date justify reducing international safeguards or physical security protection levels. All of the reprocessing or recycling technologies evaluated to date still need rigorous safeguards and high levels of physical protection.”

It should be noted that this study only analyzed the direct usability of these materials in nuclear weapons without further processing. It did not consider the potential for theft and off-site purification of these materials. As we and our colleagues have noted at length elsewhere, alternative reprocessing technologies under consideration do not confer significant self-protection against theft.

If stolen, these materials could be readily processed to produce even more attractive materials for weapons use.

One of the Atomic Insights blog post replies (Steve Darden, September 3), claimed that I misrepresented Bathke’s study. Darden asserted that the statements I made regarding the study’s conclusions with regard to subnational groups (terrorists) actually applied only to state-level actors. However, Darden is wrong. If he had actually read any of Bathke’s reports, he would have learned that the so-called Figure of Merit (FOM1) that I used “is applicable for evaluating the attractiveness of SNM or ANM for a sub-national group, for most of the less advanced proliferant nations, or for a technically advanced proliferant state.”
The other Figure of Merit (FOM2), which Mr. Darden asserts is designed for a “sub-state level actor,” is actually intended only “for a very few relatively unadvanced proliferant nations that desire a reliably high yield.” Thus Mr. Darden is wrong in attacking me for “abusing such metrics.”
Notes:
[1] A. Machiels, S. Massara and C. Garzenne, “Dynamic Analysis of a Deployment Scenario of Fast Burner Reactors in the U.S. Nuclear Fleet,” Proceedings of the Global 2009 Conference, Paris, France, September 8-11, 2009, pp. 2567-2574. Also cited in the testimony of J. Kessler, EPRI, to the July meeting of the Reactor and Fuel Cycle Technology Subcomittee of the Blue-Ribbon Commission.
[2] C. Bathke et al., “An Assessment of the Attractiveness of Material Associated with a MOX Fuel Cycle From as Safeguards Perspective,” 50th Annual Meeting of the Institute of Nuclear Materials Management, Tucson, AZ, July 2009.
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9 comments:

  1. Ed Lyman of UCS - Defending The Technical Accuracy of His Presentation to the Blue Ribbon Commission
    by Rod Adams
    A couple of weeks ago, I wrote about Dr. Ed Lyman's testimony in front of the Blue Ribbon Commission on America's Nuclear Future in a post titled Union of Concerned Scientists Opposes ALL Proposed Used Fuel Recycling Efforts. I asked readers to watch his presentation and dissect it from a technical perspective.

    Dr. Lyman has responded to my post and your comments in a rather dismissive, but lengthy post on the UCS "All Things Nuclear" blog titled Fact, Fiction and Faith: The Endless Debate Over Reprocessing. Go to
    http://atomicinsights.blogspot.com/

    ReplyDelete
  2. Here is a second comment that I just added and managed to remember to copy before submitting it to the moderation process.

    Dr. Lyman:

    You wrote:

    "Numerous studies have shown that fast reactor (FR) recycle systems are very slow and inefficient in actually fissioning transuranic elements, even if they operate in burner mode with very low conversion ratios."

    I know that we have a completely different view of the world. Let me state the same facts in a different way:

    "Numerous studies have shown that fast reactor (FR) recycle systems use very little fuel each day as they slowly fission transuranic elements and turn them into useful heat. If the fissioning is done in the presence of fertile isotopes in a configuration that approaches a conversion ration of 1:1, the total inventory of fissile isotopes will be essentially constant.

    The process will have to continue for thousands of years in order to make a significant reduction in the world's inventories of actinides. That important work of turning actinides into heat and then into useful energy will require hundreds of thousands of technically trained workers and provide useful energy for billions of people for the foreseeable future."

    ReplyDelete
  3. Update: (Posted on September 18, 2010 at 1030)

    Here is one more comment that I added to Dr. Lyman's post. I am posting it here just in case it never becomes visible at the UCS site.

    Dr. Lyman:

    You wrote:

    "It concluded that there is no “silver bullet” technology that would eliminate the safeguards and security issues associated with reprocessing, and also that “none of the proposed flowsheets examined to date justify reducing international safeguards or physical security protection levels. All of the reprocessing or recycling technologies evaluated to date still need rigorous safeguards and high levels of physical protection.” "

    I have read the Bathke studies (warning for low bandwidth users - link leads to a 8.1 MB scanned PDF) and talked to one of the primary authors of the paper, Dr. Barley Ebbinghaus. You have accurately reproduced the bottom line conclusion that there is no silver bullet that will completely eliminate the possibility of using recycled nuclear fuel materials in an "explosive device".

    The material is undoubtably fissionable and CAPABLE of being forced to explode by groups that either have a very high level of technical sophistication OR a low threshold for self protection, predictability, and fission yield.

    It is also capable of being assembled into reactors to produce a controllable, emission free source of reliable heat that lasts a very long time, so it has incredible potential value in a world that is faced with a constrained supply of useful fuel materials.

    One thing that a careful reader of Bathke's work will gain is an appreciation of the fact that the weapons designers agree that the higher the overall burn-up the less attractive the resulting material is for anyone - sub-national group, for most of the less advanced proliferant nations, or for a technically advanced proliferant state. The calculated Figure of Merit never dips below a threshold of 1.0, so the material still requires protection, but the FOM does fall rather substantially with higher and higher exposure to neutrons. (An FOM below 1.0 would indicate that it is physically impossible to achieve a critical mass which would completely eliminate the possibility of an explosion.)

    "The FOM1 of Pu and Pu+Np decreases significantly with increasing burn-up, because the concentrations of 239-Pu and 241-Pu (i.e. the isotopes with relatively high fission cross sections) decrease and the concentration of 238-Pu, which is an intense heat source, increases with increasing burn-up."

    That is what recycle systems do - they keep exposing weapons usable material to neutrons and make them less and less attractive. At the same time, those systems extract more and more energy value out of the material.

    In my conversation with Dr. Ebbinhaus, made it clear that he and his fellow authors were not arguing against recycle. They support technology programs that put fissionable and fissile material back into reactors. Power reactors are safe places to store the material, to get more useful energy out, and to continue to degrade the material's attractiveness as a weapons material.

    A primary conclusion of their work, however, reminds nuclear fuel cycle innovators that there is little they can do to completely eliminate the potential that someone might want to use fissionable material to do harm. We must continue to invest in the physical protection systems and safeguards that make it possible to both use nuclear energy and to halt the potential for nuclear explosions.

    That is really no different from the notion that we cannot fly in airplanes without some security precautions that prevent nefarious individuals from turning those very useful tools into explosive weapons of mass destruction capable of destroying large areas of populated major cities. (Of course, that never happens, does it?)

    Rod Adams
    Publisher, Atomic Insights

    ReplyDelete
  4. Update: (Posted on September 18, 2010 at 1030)

    Here is one more comment that I added to Dr. Lyman's post. I am posting it here just in case it never becomes visible at the UCS site.

    Dr. Lyman:

    You wrote:

    "It concluded that there is no “silver bullet” technology that would eliminate the safeguards and security issues associated with reprocessing, and also that “none of the proposed flowsheets examined to date justify reducing international safeguards or physical security protection levels. All of the reprocessing or recycling technologies evaluated to date still need rigorous safeguards and high levels of physical protection.” "

    ReplyDelete
  5. I have read the Bathke studies (warning for low bandwidth users - link leads to a 8.1 MB scanned PDF) and talked to one of the primary authors of the paper, Dr. Barley Ebbinghaus. You have accurately reproduced the bottom line conclusion that there is no silver bullet that will completely eliminate the possibility of using recycled nuclear fuel materials in an "explosive device".

    ReplyDelete
  6. The material is undoubtably fissionable and CAPABLE of being forced to explode by groups that either have a very high level of technical sophistication OR a low threshold for self protection, predictability, and fission yield.

    It is also capable of being assembled into reactors to produce a controllable, emission free source of reliable heat that lasts a very long time, so it has incredible potential value in a world that is faced with a constrained supply of useful fuel materials.

    ReplyDelete
  7. One thing that a careful reader of Bathke's work will gain is an appreciation of the fact that the weapons designers agree that the higher the overall burn-up the less attractive the resulting material is for anyone - sub-national group, for most of the less advanced proliferant nations, or for a technically advanced proliferant state. The calculated Figure of Merit never dips below a threshold of 1.0, so the material still requires protection, but the FOM does fall rather substantially with higher and higher exposure to neutrons. (An FOM below 1.0 would indicate that it is physically impossible to achieve a critical mass which would completely eliminate the possibility of an explosion.)

    "The FOM1 of Pu and Pu+Np decreases significantly with increasing burn-up, because the concentrations of 239-Pu and 241-Pu (i.e. the isotopes with relatively high fission cross sections) decrease and the concentration of 238-Pu, which is an intense heat source, increases with increasing burn-up."

    That is what recycle systems do - they keep exposing weapons usable material to neutrons and make them less and less attractive. At the same time, those systems extract more and more energy value out of the material.

    In my conversation with Dr. Ebbinhaus, made it clear that he and his fellow authors were not arguing against recycle. They support technology programs that put fissionable and fissile material back into reactors. Power reactors are safe places to store the material, to get more useful energy out, and to continue to degrade the material's attractiveness as a weapons material.

    A primary conclusion of their work, however, reminds nuclear fuel cycle innovators that there is little they can do to completely eliminate the potential that someone might want to use fissionable material to do harm. We must continue to invest in the physical protection systems and safeguards that make it possible to both use nuclear energy and to halt the potential for nuclear explosions.

    That is really no different from the notion that we cannot fly in airplanes without some security precautions that prevent nefarious individuals from turning those very useful tools into explosive weapons of mass destruction capable of destroying large areas of populated major cities. (Of course, that never happens, does it?)

    Rod Adams
    Publisher, Atomic Insights

    ReplyDelete
  8. One thing that a careful reader of Bathke's work will gain is an appreciation of the fact that the weapons designers agree that the higher the overall burn-up the less attractive the resulting material is for anyone - sub-national group, for most of the less advanced proliferant nations, or for a technically advanced proliferant state. The calculated Figure of Merit never dips below a threshold of 1.0, so the material still requires protection, but the FOM does fall rather substantially with higher and higher exposure to neutrons. (An FOM below 1.0 would indicate that it is physically impossible to achieve a critical mass which would completely eliminate the possibility of an explosion.)

    ReplyDelete
  9. "The FOM1 of Pu and Pu+Np decreases significantly with increasing burn-up, because the concentrations of 239-Pu and 241-Pu (i.e. the isotopes with relatively high fission cross sections) decrease and the concentration of 238-Pu, which is an intense heat source, increases with increasing burn-up."

    That is what recycle systems do - they keep exposing weapons usable material to neutrons and make them less and less attractive. At the same time, those systems extract more and more energy value out of the material.

    In my conversation with Dr. Ebbinhaus, made it clear that he and his fellow authors were not arguing against recycle. They support technology programs that put fissionable and fissile material back into reactors. Power reactors are safe places to store the material, to get more useful energy out, and to continue to degrade the material's attractiveness as a weapons material.

    A primary conclusion of their work, however, reminds nuclear fuel cycle innovators that there is little they can do to completely eliminate the potential that someone might want to use fissionable material to do harm. We must continue to invest in the physical protection systems and safeguards that make it possible to both use nuclear energy and to halt the potential for nuclear explosions.

    That is really no different from the notion that we cannot fly in airplanes without some security precautions that prevent nefarious individuals from turning those very useful tools into explosive weapons of mass destruction capable of destroying large areas of populated major cities. (Of course, that never happens, does it?)

    Rod Adams
    Publisher, Atomic Insights

    ReplyDelete