Medical Isotope Production Without Highly Enriched Uranium (2009)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

1 Background and Study Task S ection 630 of the Energy Policy Act of 2005 (the 2005 Act; see Appen­ dix A) directed the Secretary of Energy to enter into an arrangement with the National Academy of Sciences to conduct a study on the elimi- nation of highly enriched uranium (HEU; Sidebar 1.1) in reactor fuel, reactor targets, and medical isotope production facilities. The 2005 Act specifically directed that the study should address the following four points: 1. The feasibility of procuring supplies of medical isotopes from com- mercial sources that do not use HEU. 2. The current and projected demand and availability of medical iso- topes in regular current domestic use. 3. The progress that is being made by the Department of Energy (DOE) and others to eliminate all use of HEU in reactor fuel, reactor tar- gets, and medical isotope production facilities. 4. The potential cost differential in medical isotope production in the reactors and target processing facilities if the products were derived from production systems that do not involve fuels and targets with HEU. The 2005 Act defines medical isotopes to include “molybdenum 99, iodine 131, xenon 133, and other radioactive materials used to produce   Public Law 109-58.   Medical isotopes are a class of radioactive isotopes (radioisotopes) that have unstable nuclei and emit radiation. This radiation is used for medical imaging and treatment. A report of the  

 MEDICAL ISOTOPE PRODUCTION WITHOUT HIGHLY ENRICHED URANIUM SIDEBAR 1.1 HEU Almost all uranium found in nature contains about 0.7 percent by weight of uranium-235 (U-235) and about 99.3 percent by weight uranium-238 (U-238) along with minor amounts of other uranium isotopes, for example, uranium-234. Enrichment is a process used to increase the concentration of the U-235 isotope relative to U-238. HEU is defined as uranium enriched to concentrations greater than or equal to 20 percent by weight in U-235. Uranium enriched to concentra- tions less than 20 percent by weight in U-235 is LEU. Uranium is enriched by exploiting the small (three-neutron) mass difference between U-235 and U-238. Two enrichment processes are in commercial use today: an older and less efficient gaseous diffusion process that was developed during World War II and is still being used in the United States; and a more effi­cient gas centrifuge process that is being used in Europe, Russia, and other countries. Two centrifuge facilities are currently being constructed in the United States. A third enrichment process (laser enrichment) has been developed but is not used commercially. Enriched uranium is used to fuel the majority of today’s research and com- mercial nuclear reactors. Ordinary water is used as a coolant and moderator for light-water reactors (LWRs) that typically use LEU fuel enriched in U-235 up to about 5 percent by weight. The majority of commercial nuclear reactors that produce about 16 percent of the world’s electrical power are LWRs. Most existing research and test reactors were designed to use HEU fuel, but many of these have been or are being converted to LEU fuel (see Chapter 11). Most of the world’s production of Mo-99 is carried out by irradiating HEU targets in research and test reactors that are fueled with LEU. With one e ­ xception, the United States is currently the world’s primary supplier of HEU for Mo-99 production, either directly through DOE or indirectly through the European organization Euratom Supply Agency (ESA). The U.S.-origin HEU that is used for Mo-99 production has an enrichment of about 93 percent U-235 and was originally produced for use in nuclear weapons. The exception is South Africa, which uses its own HEU (which is 45 percent enriched) to radiopharmaceuticals for diagnostic, therapeutic procedures or for research and development.” However, this report focuses on the production and use of molybdenum-99 (Mo-99) for reasons that are described at the beginning of Chapter 2. Section 630 of the 2005 Act determines the production of medical isotopes using low enriched uranium (LEU) to be feasible if the following conditions are met: National Research Council and the Institute of Medicine (NRC and IOM, 2007) provides a discussion of the uses of medical isotopes in medicine and research. 

BACKGROUND AND STUDY TASK  produce Mo-99 in a reactor that is also fueled with HEU but is in the process of being converted to LEU. ESA has also received HEU from Russia, and some of this HEU has been used to fuel three European reactors: the High Flux Reactor of the Institut Laue- Langevin, which is located in Grenoble, France; the Orpheus Reactor, which is located in Saclay, France; and the FRM II Reactor, which is located in Garching, Germany. (See http://www.francenuc.org/en_sources/sources_unat_e.htm for a discussion of HEU use in France.) None of these reactors is used to produce Mo-99. ESA does not publicly disclose the sources of HEU used for the manu- facture of targets for medical isotope production. Most of this HEU is probably of U.S. origin, but some may also be of U.K. origin. The primary concern with civilian use of HEU for applications such as Mo-99 production is its attractiveness for use in improvised nuclear devices by terrorists or rogue states. The amount of HEU required to achieve a sustained nuclear chain reaction (referred to as the critical mass) depends on the enrich- ment of U-235 as well as the design of the device. The IAEA defines a significant quantity of a nuclear material to be the approximate quantity of material from which the possibility of manufacturing a nuclear explosive device (i.e., a device that can achieve a prompt critical mass) cannot be excluded. The IAEA signifi- cant quantity for HEU is 25 kg. The HEU-based weapon used on Hiroshima, Japan, in August 1945 contained 64 kg of HEU having an average enrichment of about 80 percent. However, a well-designed nuclear explosive device could be made with less than 25 kg of HEU. The Atomic Energy Act gives the U.S. government the authority to regulate uranium that is enriched in U-235 (and also U-233) above natural abundances. Such materials are referred to as special nuclear materials. The U.S. government requires stepped-up security for facilities that handle greater than 5 kg of HEU. As U-235 enrichment decreases, more uranium is required to achieve a prompt critical mass. It is difficult but not impossible to achieve a prompt critical mass with LEU. • LEU targets have been developed and demonstrated for use in the reactors and target processing facilities that produce significant quantities of medical isotopes to serve U.S. needs for such isotopes. • Sufficient quantities of medical isotopes are available from low enriched uranium targets and fuel to meet U.S. needs. • The average anticipated total cost increase from production of medical isotopes in such facilities without the use of HEU is less than 10 percent. During the negotiations between the National Academies and the spon- soring organization within DOE (the National Nuclear Security Adminis- 

10 MEDICAL ISOTOPE PRODUCTION WITHOUT HIGHLY ENRICHED URANIUM tration [DOE-NNSA]), it was jointly agreed that the following task would also be included as part of this study: If the National Academies determine that the procurement of medical isotopes from commercial sources is not feasible as defined in Section 630 of the Energy Policy Act, it should estimate the magnitude of the cost dif- ferential and identify additional steps that could be taken by the Depart- ment of Energy and medical isotope producers to improve the feasibility of such conversions. In estimating the magnitude of cost differentials, consideration should be given to facilities utilized by both large and small producers. The National Academies should also identify any reliability of supply issues that could arise as a result of such conversions. DOE-NNSA and the National Academies judged that this added task would assist DOE in achieving its mandate to minimize the use of HEU in civilian applications. The complete statement of task for this study is reproduced in Sidebar 1.2. The mandate for this study reflects an effort by the U.S. Congress to balance two competing national interests: first, to ensure the continued availability of reasonably priced medical isotopes in the United States; and second, to prevent the proliferation of HEU, which could be diverted for malevolent use in nuclear explosive devices (Sidebar 1.1). A brief history of congressional actions on HEU use for medical isotope production is provided in Sidebar 1.3. Kuperman (2005, 2006) explores the motivations for and possible consequences of these actions. At present, there are no producers of Mo-99 for medical use in the United States. Almost all of the Mo-99 used worldwide is produced by just four companies, all using HEU targets: • MDS-Nordion, which is located in Ottawa, Ontario, Canada, o ­ btains Mo-99 under an agreement with Atomic Energy of Canada Limited (AECL), which is located at Chalk River, Canada; • Mallinckrodt near Petten, the Netherlands, extracts Mo-99 from targets irradiated in three European reactors; • Institut National des Radioéléments (IRE) near Fleurus, Belgium, extracts Mo-99 from targets irradiated in three European reactors; and   This additional task was formally approved by DOE-NNSA and the National Academies prior to the start of the study.   In this report, the terms Mo-99 production, Mo-99 producer, and similar constructions refer specifically to Mo-99 produced for medical isotope use. All uranium-fueled nuclear r ­ eactors produce Mo-99 as a result of fission of U-235 contained in their reactor fuels, but this Mo-99 is not recovered for medical use.   Mallinckrodt Inc., a Delaware corporation, is an indirect wholly owned subsidiary of Covidien Ltd. 

BACKGROUND AND STUDY TASK 11 SIDEBAR 1.2 Study Task The National Academies will conduct a study and provide findings and r ­ ecommendations to DOE on the production of medical isotopes without HEU. As mandated by Congress in Section 630 of the Energy Policy Act of 2005, the study will determine the following: 1. The feasibility of procuring supplies of medical isotopes from com- mercial sources that do not use HEU, using the definition of feasibility defined in Section 630 of the Energy Policy Act of 2005. 2. The current and projected demand and availability of medical isotopes in regular current domestic use. 3. The progress that is being made by DOE and others to eliminate all use of HEU in reactor fuel, reactor targets, and medical isotope production facilities. 4. The potential cost differential in medical isotope production in the r ­ eactors and target processing facilities if the products were derived from produc- tion systems that do not involve fuels and targets with HEU. If the National Academies determine that the procurement of medical iso- topes from commercial sources is not feasible as defined in Section 630 of the Energy Policy Act, it should estimate the magnitude of the cost differential and identify additional steps that could be taken by DOE and medical isotope p ­ roducers to improve the feasibility of such conversions. In estimating the mag- nitude of cost differentials, consideration should be given to facilities utilized by both large and small producers. The National Academies should also identify any reliability of supply issues that could arise as a result of such conversions. With respect to the first charge, Congress established three tests for feasibility: 1. LEU targets have been developed and demonstrated for use in the r ­ eactors and target processing facilities that produce significant quantities of medi- cal isotopes to serve U.S. needs for such isotopes; 2. Sufficient quantities of medical isotopes are available from LEU targets and fuel to meet U.S. needs; and 3. The average anticipated total cost increase from production of medical isotopes in such facilities without the use of HEU is less than 10 percent. • Nuclear Technology Products (NTP) Radioisotopes extracts Mo-99 from targets irradiated in a reactor near Pelindaba, South Africa. Approximately 40–50 kg of HEU are used annually for medical isotope production (NNSA and ANSTO, 2007), including annual U.S. exports of   This is a report from a conference that involved almost all of the Mo-99 production com- munity. The report was produced by a working group during the conference. 

12 MEDICAL ISOTOPE PRODUCTION WITHOUT HIGHLY ENRICHED URANIUM SIDEBAR 1.3 Congressional Actions on HEU Use for Medical Isotope Production U.S. congressional efforts to reduce the use of HEU for isotope production date from the early 1990s. The Energy Policy Act of 1992 (the 1992 Act) required that foreign producers who received HEU from the United States cooperate in converting to LEU-based production. This section of the 1992 Act, which is some- times referred to as the Schumer Amendment after its sponsor, Senator Charles Schumer (D-NY), reads, in part, as follows: The [Nuclear Regulatory] Commission may issue a license for the export of highly enriched uranium to be used as a fuel or target in a nuclear research or test reactor only if, in addition to any other requirement of this Act, the Commission determines that—(1) there is no alternative nuclear reactor fuel or target enriched in the isotope 235 to a lesser percent than the proposed export, that can be used in the reactor; (2) the proposed recipient of that uranium has provided assurances that, whenever an alternative nuclear reactor fuel or target can be used in that reactor, it will use that alternative in lieu of highly enriched uranium; and (3) the United States Government is actively developing an alternative nuclear reactor fuel or target that can be used in that reactor. . . . the term “alternative nuclear reactor fuel or target” means a nuclear reactor fuel or target which is enriched to less than 20 percent in the isotope U-235. The Energy Policy Act of 2005 exempts certain HEU recipient countries, specifically Belgium, Canada, France, Germany, and the Netherlands, from some provisions of the Schumer Amendment. The section of the 2005 Act referred to as the Burr-Bond Amendment, after its sponsors, Representative Richard Burr (R-NC) and Senator Christopher (Kit) Bond (R-Mo), reads, in part, as follows: The [Nuclear Regulatory] Commission may issue a license authorizing the export (including shipment to and use at intermediate and ultimate consignees specified in the license) to a recipient country of highly enriched uranium for medical isotope production if, in addition to any other requirements of this Act (except subsection a.), the Commission determines that—(A) a recipient country that supplies an assurance letter to the United States Government in connection with the con- sideration by the Commission of the export license application has informed that United States Government that any intermediate consignees and that ultimate consignee specified in the application are required to use the highly enriched uranium solely to produce medical isotopes; and (B) the highly enriched uranium for medical isotope production will be irradiated only in a reactor in a recipient country that—(i) uses an alternative nuclear reactor fuel; or (ii) is the subject of an agreement with the United States Government to convert to an alternative nuclear reactor fuel when alternative nuclear reactor fuel can be used in the reactor. 

BACKGROUND AND STUDY TASK 13 about 15.5 kg of HEU to Canada. All of the U.S. supply of medical isotopes is provided by MDS-Nordion and Mallinckrodt, either through their own production or through backup supply agreements with each other and with IRE and NTP. The United States currently consumes about half of world production of Mo-99. As described in the Regional Producers section of Chapter 3, there are two organizations that are or soon will be able to produce Mo-99 using LEU: • Comisión Nactional de Energía Atómica (CNEA) in Buenos Aires, Argentina, has been producing Mo-99 using LEU since 2002. CNEA makes Mo-99 primarily for domestic and regional use. • Australian Nuclear Science and Technology Organisation ­(ANSTO) in Lucas Heights, Australia, plans to begin producing Mo-99 using the CNEA-developed process in the near future. Both of these producers are interested in becoming global suppliers. Additionally, the International Atomic Energy Agency is sponsoring a co- ordinated research project (discussed in Chapters 3 and 11) to help other countries develop LEU-based production for indigenous use. STRATEGY TO ADDRESS THE STUDY CHARGE This study was carried out by a committee of experts appointed by the president of the National Academy of Sciences acting in his capacity as chair of the National Research Council. The committee consists of 14 members with expertise that spans the issues relevant to the study task: chemistry, chemical and nuclear engineering, radiochemistry, construction and infrastructure management, economics, isotope production, nuclear medicine, nuclear security, radioactive waste management, and risk assess- ment. In selecting the membership of this committee, the National Research Council sought to obtain a balance between members with experience in the production and use of medical isotopes and members with relevant disciplinary expertise but no direct medical isotope experience. The com- mittee leadership also reflects this balance: the committee chair is an acad- emy member with demonstrated leadership capabilities but no experience in medical isotope production; the vice chair is also an academy member and has experience as a medical isotope user. Biographical sketches of the committee members are provided in Appendix B. Given both the importance of this congressional request and the con- troversy surrounding the use of HEU for medical isotope production, the committee understood that it needed to reach out broadly to interested and potentially affected parties to obtain information for this study. The 

14 MEDICAL ISOTOPE PRODUCTION WITHOUT HIGHLY ENRICHED URANIUM committee held four meetings to receive information from subject matter experts, representatives of the medical isotope production and user com- munities, and congressional and federal agency staff (Appendix C). Small groups of committee members also toured medical isotope production and/or technetium generator manufacturing facilities at AECL and MDS-Nordion (Chalk River and Ottawa, Canada, respectively), Mallinckrodt (Petten, the Netherlands, and Maryland Heights, Missouri), IRE (Fleurus, Belgium), ANSTO (Lucas Heights, Australia), and CNEA/ I ­ nvestigaciones Aplicadas Sociedad del Estado (INVAP; Buenos Aires, A ­ rgentina). A small group of members also toured the University of M ­ issouri Research Reactor (MURR; Columbia, Missouri) and the ­reactor fuel and target fabrication facility operated by Compagnie pour l’Etude et la ­ Réalisation de Combustibles Atomiques (CERCA; near Romans, France). Some organizations provided proprietary information for this study through nondisclosure agreements with the National Academies. This informa­tion primarily addressed issues such as isotope production pro- cesses, future plans, and potential barriers to conversion from HEU to LEU. None of the proprietary information received by the National Academies appears in this report. Given the broad task statement for this study, the committee recognized early on that it needed to establish boundaries to guide its inquiries. Specifi- cally, the committee decided that: • The study would focus on the reactor production of the medical isotope Mo-99 and its decay product Tc-99m for reasons described in Chapter 2. • Financial feasibility of LEU production would be assessed at several points in the Mo-99 supply chain (Chapter 10). • The discussion of the third charge of the task statement (Side- bar 1.2) would emphasize progress being made in the elimination of HEU targets for medical isotope production (Chapters 7–10) but would also discuss elimination of HEU fuel in reactors (Chapter 11). REPORT ROADMAP The report is organized into a number of chapters that address the ele- ments of the study charge. • This chapter provides the background and study task for the report. • A short primer on Mo-99 production and use is provided in Chap- ter 2. It is intended primarily for nonexpert readers who wish to gain a 

BACKGROUND AND STUDY TASK 15 better understanding of how this isotope is currently being made and how its decay product, Tc-99m, is used for medical imaging. • Mo-99 supply and supply reliability are discussed in Chapters 3 and 4. • Current and projected Mo-99 demand is discussed in Chapter 5. • Mo-99/Tc-99m production cost estimates are provided in Chap- ter 6. These estimates are used in the feasibility assessment that appears in Chapter 10. • Several considerations for conversion of reactor targets from HEU to LEU are discussed in Chapters 7–9: technical (Chapter 7), regulatory (Chapter 8), and general approaches and timing (Chapter 9). • The prospects and feasibility of converting HEU-based Mo-99 pro- duction to LEU-based production are discussed in Chapter 10. This chapter also contains the committee’s response to the feasibility assessment portions of the study charge. • Progress that is being made by DOE in eliminating use of HEU in reactors is discussed in Chapter 11. An effort was made by the committee to develop chapters that could stand alone for the benefit of audiences who were not interested in reading the entire report. This results in some repetition of basic facts and concepts in the chapters that will be noticed by readers who peruse the report from beginning to end.