ANS sends DOE recommendations on ATW
At the request of President Andy Kadak, ANS members reviewed the DOE's report on the development of Accelerator Based Transmutation of Wastes (ATW). A letter with the recommendations and comments based on the ANS review was sent to Under Secretary Ernest Moniz, other Department of Energy directors, members of Congress, and others.
May 5, 2000
Dr. Ernest Moniz
Under Secretary
Department of Energy
1000 Independence Avenue, SW
Room 7B-252
Washington, DC 20585
Subject: Accelerator Based Transmutation of Wastes (ATW)
Dear Dr. Moniz:
The American Nuclear Society (ANS) has reviewed, at my request, "A Roadmap for Developing Accelerator Transmutation of Waste (ATW) Technology (DOE/RW-0519) issued on November 1, 1999.
Dr. Rusi P. Taleyarkhan chaired our review team. It included five members of our Accelerator Applications Division who possessed a broad spectrum of expertise and are also affiliated with various other ANS technical divisions. These five ANS members reviewed the technical aspects of the "Roadmap" report. Since the primary purpose of the use of accelerators in this application is the transmutation of nuclear waste, the ATW technical review1 has been supplemented by a paper on transmutation economics2 and two papers3, 4 on alternatives to ATW by independent experts to provide a broader perspective on the overall issue of transmutation. The full report of the ATW roadmap review team is enclosed as are summaries of the additional papers for your review and information.
The general conclusions based on the above can be summarized as follows:
- The decision to pursue accelerator transmutation of waste should be examined in the context of other options such as reactor based systems that may be as effective. All options should be compared on safety, economic and process (waste stream and feasibility) criteria to assess which has the best chance of meeting the objectives set forth for transmutation.
- The assumptions of the "Roadmap" relative to producing power at competitive costs to pay for the ATW is highly uncertain given today's competitive electricity market. Professor Driscoll2 assumes that the electricity produced by an actinide burner reactor can pay for the capital and operating costs of the reactor, but concludes that the increase in nuclear fuel cycle costs for other parts of the process are on the order of a factor of four compared to current light water reactors. While Driscoll's analysis is based on a reactor option, his assumptions and conclusions also appear applicable to accelerator based systems. The issue is who will pay for these additional costs in a deregulated power market. For ATW, the prices quoted for cost of power are high relative to today's electricity prices. This issue needs to be explored in more depth.
- While significant claims are being made about the feasibility of transmutation, no serious analyses of the effectiveness of transmutation and its impact on the repository design is available to our knowledge. In particular, if only commercial nuclear power spent fuel is used in the transmutation cycle, the cost and design of the repository would remain essentially unchanged due to the significant quantity of DOE defense waste that also has to be disposed. What is also not sufficiently analyzed is how Technicium 99 and Iodine 129 will be handled in the transmutation process. Both isotopes have a considerable effect on dose analyses and could be difficult to transmute significantly in accelerator, reactor or accelerator-reactor based hybrid systems.
- ATW could be built with known technologies and no need exists for pure-science research. The main unknown and biggest challenge concerns the overall integration of these technologies into a cost effective system that has acceptable system performance.
- Accelerator technology for ATW can draw heavily on projects such as the Spallation Neutron Source and Accelerator Production of Tritium. The ATW project should align itself closely with these projects to reduce R&D costs.
- The heavy reliance of the Roadmap on Lead-Bismuth-Eutectic technology to be procured from the Russian submarine program is a source of concern and enhances risk.
- A comprehensive safety analysis is necessary for all transmutation component systems (e.g. accelerator, target-blanket) including pre and post processing of waste streams leading to eventual disposal. The overall safety of the integrated system needs to be assessed.
- The impact of Nuclear Regulatory Commission certification or licensing is an unknown and may possibly have significant impact on the cost and schedule.
- Accelerator reliability is an issue that needs to be resolved.
- The potential lack of US experience in large scale radio-chemical processing when actually needed for ATW or any other viable transmutation undertaking could pose significant challenges to the program. With the aging of the work force and other factors, long term capability in this area is a concern for the program.
- The liquid sodium and helium coolant options seem to have been dismissed too early in the decision making process. Most of the US and international data and experience with liquid metal coolants is with sodium.
- It is not clear whether substantial benefits will emanate from a far-reaching international collaboration primarily because access to data and rigors with which work would proceed. The concern is whether the research work will produce the information required by the Nuclear Regulatory Commission or the Defense Nuclear Facilities Safety Board for siting in the US or will separate and special research programs have to be instituted in the US. This issue needs to be addressed early in the international collaboration process to be sure that the expectations of such collaboration are achieved.
As to other options for transmutation, Baxter and Rodriguez3 have proposed an interesting gas reactor solution to transmutation that combines accelerators with critical reactors that use both fast and thermal spectra to treat fission products as well as minor actinides. MIT and the Idaho National Engineering and Environmental Laboratory4 are developing a lead-bismuth reactor that may have the potential for both electric generation and transmutation. It appears that there are many opportunities for combining some of the good ideas found in reactor based and accelerator based options for transmutation that could yield a more effective research program.
All these technologies, however, raise two significant overarching questions. The first is that these technologies appear to suffer from poor economics relative to direct disposal. The ATW Roadmap concludes that the $280 Billion for a full ATW system will pay for itself from the electricity sold. When one compares it to the $40 Billion (or so) for life cycle cost for disposal that is already being paid for by rate payers, one must ask whether the price of electricity estimated to fund the ATW effort is realistic in the competitive market. Should the cost of the system, whether ATW or reactor based, not pay for itself through competitive electricity sales, the cost of transmutation will be borne by the generators of nuclear produced electricity which, as Professor Driscoll2 points out in his paper, will make nuclear power less competitive relative to alternatives.
The second major question is the very important question of the real feasibility of transmutation that is advertised to make a 10,000-year problem, a 300-year problem. Whether this is practical or technically feasible has not been established, even theoretically, using real system assumptions given the neutronics and processes involved.
Based on this information, the American Nuclear Society recommends:
- Before proceeding much further on any of these technologies, perform an integrated systems analysis of the realistic capabilities of any transmutation system in terms of the objectives desired to reduce the time required for isolation of high level wastes from 10,000 years to 300 years using the transmutation process. This analysis should use current Environmental Protection Agency toxicity or hazard indices and provide a fair evaluation of the effectiveness, volumes processed, the time it will take to treat the reprocessed spent fuel, the final waste streams and disposal options for the entire process. At the present time, there does not appear to be such a comprehensive analysis upon which to base policy, technology or a research program.
- Include DOE defense wastes in any transmutation program to realize the ultimate objectives of transmutation and ultimate disposal.
- The current transmutation of waste project is currently mandated to remain focused on accelerator driven systems only. The American Nuclear Society recommends that work on transmutation options be expanded to include stand-alone critical systems or hybrid accelerator-subcritical reactor systems.
- Consider the licensing implications of any technology path with the focus on the safety implications of the options. Initiate early-on, direct dialog and planning with stipulated regulatory/licensing bodies such as the US NRC to assess and cost out licensing implications of any technology path with the focus on overall system safety.
- Assess realistic possibilities of international collaboration given the likelihood of access to data (Russian), standards and past large-scale research collaboration programs. Identify what needs to change to make this program successful.
We hope that you will carefully review the detailed reports attached to provide more information on the issues raised in this letter as well as other important technical suggestions and concerns. The members of the review team and other contributors would be happy to answer any questions you may have. We would be very interested in your comments on this letter and its attached reports.
Sincerely yours,
Andrew C. Kadak
President, American Nuclear Society
References:
- "Accelerator For Transmutation of Waste Roadmap Review Team Comments," Rusi P. Taleyarkhan, Chair, American Nuclear Society, Accelerator Applications Division.
- "The Economics of a Burner Reactor Using an ATW-type Fuel Cycle," Michael J. Driscoll, Massachusetts Institute of Technology, ANS Annual Meeting, San Diego, June 2000.
- "The Application of Gas-Cooled Reactor Technologies to the Transmutation of Nuclear Waste," Baxter and Rodriguez, draft paper, March 2000.
- "Conceptual Reactor Physics Design of a Lead-Bismuth-Cooled Critical Actinide Burner," Hejzlar, Kazimi and M.J. Driscoll, Massachusetts Institute of Technology, February 2000.
