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Safeguarding sensitive nuclear materials: Reinforced approaches

An overview of major factors underlying the IAEA's specific approaches for safeguarding different types of sensitive nuclear materials

iewed through the perspective of a State in- In such cases, IAEA safeguards are, in effect, by T.E.Shea and tent on the acquisition of nuclear , cer- confidence-building measures, wherein the K. Chitumbo tain nuclear materials subject to IAEA safe- Agency and the State co-operate to demonstrate guards could significantly contribute to such an the State's non-proliferation bona fides. IAEA effort. The decision to divert safeguarded mate- safeguards measures are directed to detect viola- rials would require the State to weigh the strate- tions of the relevant safeguards agreements, gic, programmatic, and economic benefits should a State be so tempted. against the risks of detection and subsequent This article looks at the major factors taken actions. into account in planning the implementation of In that context, the "sensitivity" of specific IAEA safeguards, reflecting the relative sensitiv- nuclear materials reflects two principal con- ity of different safeguarded nuclear materials. siderations. First, in the general sense, nuclear materials closest to the requirements for nu- clear- manufacture are clearly more sensitive than others. Second, in terms of a Sensitive nuclear materials specific situation, certain nuclear materials might provide important support to a State's Nuclear weapons contain fission- clandestine nuclear-weapons programme, tak- components fabricated with , highly ing into account other capabilities that might enriched (HEU) (uranium containing be available domestically or through interna- 20% or more of the uranium-235), or tional arrangements. uranium-233. Thus, the safeguards "sensitivity" In States that have not accepted comprehen- of materials, equipment, or facilities subject to sive IAEA safeguards, there are agreements of IAEA safeguards is established in relation to the more limited scope. These may also apply to ready availability of plutonium or HEU, and to non-nuclear materials, to specified equipment, the ability to produce and process them. and to nuclear or non-nuclear facilities that could Nuclear weapons can be fabricated using be important in the context of a State's efforts to plutonium containing virtually any combination acquire nuclear weapons. In such cases, the of plutonium , according to advice given adopted safeguards measures follow general re- by nuclear-weapon States. Plutonium containing quirements, and are adapted to the circumstances very high percentages of the isotope plutonium- of a specific situation. 239 is better suited than plutonium containing Safeguards are implemented in non-nuclear 10% or more of the isotope plutonium-240. weapon States under different assumptions. However, even highly burned reactor-grade plu- Most non- States have voluntar- tonium can be used for the manufacture of nu- ily accepted comprehensive IAEA safeguards on clear weapons capable of very substantial explo- all nuclear materials. Absent contrary indica- sive yields. Except for plutonium created for tions, those nuclear activities are normally pre- heat-source applications containing 80% or sumed to be of a legitimate and peaceful nature. more of the isotope plutonium-238, all pluto- nium is considered to be of equal "sensitivity" for purposes of IAEA safeguards in non-nuclear weapon States. Mr Shea is Head of the Operations A2 Section of the IAEA's Only a small amount of HEU remains in Department of Safeguards, and Mr Chitumbo is Head of the peaceful nuclear activities, primarily in research Operations C3 Section. reactor . Very little uranium-233 exists.

IAEA BULLETIN, 3/1993 23 FEATURES

Layers of safeguards activities to cover diversion strategies

IAEA safeguards measures are based on a multi- layered combination of activities that take into account potential diversion strategies (1). These strategies could include the understatement of nuclear materials (2); the misuse of facilities and (3); the borrow- ing of nuclear materials (4); and the overstatement of nuclear materials (5). To cover such specific strategies, IAEA safeguards measures include verfication (mea- surements) and auditing activities (6, 7); the verification o! design information and special inspections (8); and the use of and surveillance (C/S) and special inspections (9). These measures are specific elements of overall safeguards activities (10) that are done to verify a State's physical inventory of its safe- guarded nuclear programme and to evaluate the closing balances of safeguarded nuclear material within defined areas (material balance areas).

Other nuclear materials — for example, nat- undeclared heavy-water production or scrap re- ural uranium — may be critical to the operation covery). of an isotope production reactor or enrichment • //; States not subject to comprehensive safe- plant. The situation also could arise where safe- guards agreements, reproducing or misusing guarded might be required for the equipment that is subject to safeguards. operation of an unsafeguarded research or power reactor in a State not having a comprehensive safeguards agreement, and the reactor could be used to produce plutonium or uranium-233. Safeguards activities

Safeguards comprise a series of measures applied at specified facilities or other locations. Diversion strategies In addition to the measures traditionally applied, the IAEA is in the process of implementing mea- The safeguards approach implemented at a sures to strengthen the safeguards system. These given facility is designed to counter plausible include special inspections: increased emphasis diversion strategies. The strategies and associ- on the provision of design information and its ated concealment schemes which might be used verification: expanded reporting of transactions by a potential diverter include: involving specified materials and equipment; • The removal of nuclear material subject to and the adoption of complementary measures safeguards. This could be done with or without such as environmental sampling. The arrange- falsified records and reports (e.g., understate- ments for implementing these considerations have ments of receipts or overstatements of - not been completed. These additional measures ments, overstatements of discards and/or re- would apply first and foremost to sensitive nu- tained wastes, or overstatements of inventory clear materials subject to IAEA safeguards. declarations): with or without the substitution of The safeguards measures applied at sensitive falsified or partially falsified material: or with or nuclear facilities are based on a layered combi- without safeguarded material being borrowed nation of activities to cover the different groups from other facilities. of diversion strategies mentioned above. These • The misuse of safeguarded facilities. This activities include: could be done, for example, through undeclared Examination of design information and production of plutonium or uranium-233 in re- verification of the physical inventory. These search or power reactors; configuration and pro- activities are done to: duction of HEU in low enrichment facilities; • confirm a facility's appropriateness for the undeclared reprocessing or scrap recovery; or declared peaceful nuclear activities;

24 IAEA BULLETIN, 3/1993 FEATURES

• establish that the information is complete, accurate, and consistent, and that the facility is Facility types Sensitive nuclear Number SQ amount of nu- constructed, operated, and maintained in accor- materials of facili- clear materials dance with the information provided. The provi- ties involved sion, examination, and verification of design in- Storage Plutonium 26 3678 formation begins with the conceptual design of a HEU plant and extends over its life through Research reactors* Plutonium 102 200 decommissioning. Extensive physical verifica- HEU tion activities are carried our during plant con- Power reactors Plutonium 141 22381 struction and modifications or maintenance, dur- Reprocessing ing cold and hot plant commissioning, and to the Plutonium 6 68 extent practicable, during plant operations. fabrication plants** Plutonium 15 911 • serve as the basis for the design and imple- HEU mentation of a safeguards approach for the facil- Enrichment plants Capable of 5 ity that is intended to detect diversion or facility producing HEU ' including critical assemblies misuse; and " including conversion plant • serve as a reference basis against which com- parisons will be made over the life of the facility Notes: Data are as of the end of March 1993 and pertain to non-nuclear weapon States having to establish normal expectations and abnormal or safeguards agreements in force pursuant to the Treaty on the Non-Proliferation of Nuclear anomalous conditions. Weapons and (INFCIRC/153 agreements). Activities to cover verification of inventory SQ = Significant quantity of material. 1 SQ forplutomum = 8 kilograms. SO for highly (HEU) = 25 kilograms. changes and timeliness requirements. These in- clude: • extensive use of containment and surveil- lance (C/S) measures at facilities in areas where by appropriate non-destructive and destructive Sensitive nuclear items are controlled and where material is stored analysis according to random sampling plans. materials and in bulk. In some cases, measurement systems are C/S measures are applied to reduce measurement facilities under integrated for unattended verification. requirements, or to serve as the basis for main- comprehensive • depending on the scale and complexity of a taining continuity of knowledge over verified IAEA safeguards facility, the use of dynamic C/S systems to mon- information. itor plant operations within process areas. These Evaluation of the material balance. At the systems may incorporate plant measurement end of each physical inventory verification, the systems in combination with flow- material balance over a 1-year (maximum) pe- sheet predictions. riod is evaluated and verified. In addition, cumu- • compilation of operator data and verification lative material balances are computed over the of amounts and locations of safeguarded mate- life of the facility to ensure long-term stability. rial flows, storage inventories, and process in- ventories during plant operations to permit near- real-time accountancy (NRTA) balances over separate and combined segments of the plant. Verification of initial inventory (Other facility-specific arrangements are agreed, where appropriate.) The manner in which data Verification of the initial inventory is done to are collected and the frequency for deriving establish that the State's initial declaration of NRTA balances depend on the scale of the plant. facilities, equipment, and materials subject to a For new reprocessing plants, on-line data acqui- safeguards agreement is complete and accurate. sition is foreseen, making use of the data ac- Safeguards implementation will depend on quired in the steps above, as are on-site data whether or not a facility has been built or has analysis capabilities to permit NRTA balance been operated before safeguards are applied ini- closings as often as on a daily basis. tially, or re-applied when relevant conditions • computation of material balances (an ele- recur, as may happen for plants in non-nuclear ment of nuclear accountancy) for sub-campaigns weapon States that are not bound by comprehen- at large processing plants corresponding to con- sive safeguards agreements. tiguous operations carried out for individual cli- The investigations carried out prior to imple- ents. menting safeguards under such circumstances Verification of the physical inventory. Once resemble a form of nuclear archeology. They per year, plant operators are required to shut combine extensive examinations of plant histor- down their plants, clean out the nuclear materi- ical operating records and analysis of trace sam- als, and take physical inventory. The IAEA ver- ples from within and around a facility to confirm ifies the operator's declared physical inventory the operating records.

IAEA BULLETIN, 3/1993 25 FEATURES

Fuel cycle considerations spent fuel in geological repositories without reprocessing. As States establish more complete fuel cy- An intermediate case also has emerged: cles, the capabilities of their respective systems States export their spent fuel to a reprocessing of accountancy and control (SSACs) of nuclear complex (typically in a nuclear-weapon State) material normally increase. Such capabilities and receive in return separated plutonium or raise two diametrically opposed considerations manufactured mixed oxide (MOX) fuel assem- in safeguards implementation. First, to some ex- blies. tent, the IAEA would make use of the SSAC to A tandem fuel cycle also is under consider- meet its obligations and draw independent con- ation as a means to improve the economics of clusions. Second, the increased technical capa- heavy-water reactors. In this case, the spent fuel bilities and control typically established in States discharged from -water reactors is "re- with extensive civil nuclear programmes could canned" without reprocessing. be used to support sophisticated diversion con- Each of these cases raises new possibilities cealment strategies. and challenges to ensure that the scope and focus Throughout most of the history of peaceful of safeguards remain relevant. nuclear activities, an argument grounded on the utilization of energy resources has driven the notion that a State's industry Sensitivity of specific situations would not be complete until it had mastered all elements of the front and back ends of the "fuel States with nuclear weapons programmes cycle". This includes uranium enrichment, fuel have chosen, with very few minor exceptions, to fabrication, nuclear power reactor design and create separate installations specifically in sup- construction, spent fuel reprocessing, and pluto- port of that purpose. nium fuel fabrication for in light-water In non-nuclear weapon States, as additional power reactors or for use in breeder reactors. fuel-cycle capabilities are established, the ability However, owing to very low uranium prices and to acquire nuclear weapons through diversion or high costs associated with reprocessing and plu- facility misuse increases. First, access to inven- tonium fuel fabrication, this situation has not tories of separated plutonium increases as the materialized. Most States have, perhaps by de- number of facilities and the size of the invento- fault, elected a "once-through" option for fuel- ries grow. Second, opportunities for concealing ling light-water reactors, intending to store the diversion increase, for example, by borrowing

Facilities under safeguards or Number of facilities (number of installations) containing safeguarded Facility category INFCIRC/153 INFCIRC/66/ Nuclear-weapon Total materials at the agreements Rev. 2 agreements States end of 1992 Power reactors 151 (182) 13(17) 2(2) 166(201) Research reactors and 134(145) 22 (22) 2(2) 158(169) critical assemblies Conversion plants 6(7) 3(3) 0(0) 9(10) Fuel fabrication plants 33(34) 9(9) 1(1) 43(44) Reprocessing plants 5(5) 1(1) 0(0) 6(6) Enrichment plants 5(5) 1(1) KD 7(7) Separate storage facilities 35 (36) 6(6) 5(5) 46 (47) Other facilities 54(57) 4(4) 0(0) 58(61) Subtotals 423(471) 59(63) 11(11) 493 (545) Other locations 290 (468) 28 (32) 0(0) 318(500) Non-nuclear instalations 0(0) 3(3) 0(0) 3(3) Totals 713(939) 90 (98) 11(11) 814(1048)

Notes: Data in the category for INFCIRC/153, which refers to comprehensive safeguards agreements pursuant to the Treaty on the Non-Proliferation of Nuclear Weapons and/or Treaty of Tlatelolco, exclude locations in . The category for INFCIRC/66/Rev.2 excludes installations in nuclear-weapon States but includes installations in Taiwan, China.

26 IAEA BULLETIN, 3/1993 FEATURES among facilities, or through cumulative limita- material transfers, and transfers of other materi- tions in the sensitivity of verification activities. als and items that have been specifically identi- Thirdly, as civil activities increase, the pool of fied (in IAEA document INFCIRC/254). knowledgeable specialists in certain technologi- In addition to these sources of information, it cal areas will expand, providing a support base has been acknowledged that Member States of which could facilitate weapons-related activi- the IAEA are obligated to advise the Agency of ties. credible information suggesting that a State may be in violation of its non-proliferation obliga- tions. Such information will be used in conjunc- Strengthened support and transparency tion with other information, as available, in de- termining the need for clarifications, official vis- In the aftermath of the Iraqi experience, its or, in appropriate cases, special inspections. where the IAEA discovered a clandestine nu- Moreover, information from the analysis of clear-weapons programme, important lessons water, air, and soil samples may provide indica- emerged for the implementation of effective tions of undeclared enrichment or reprocessing. safeguards. They include the need for greater The exists to provide a significant transparency in nuclear operations so that peace- verification capability through this means; the ful nuclear activities can proceed with the confi- arrangements have not been established yet. dence of the international community. This IAEA safeguards are in an important state of transparency can be gained to a certain extent transition. The adoption of such extended capa- through improvements in IAEA safeguards, but bilities into routine safeguards implementation is perhaps to a greater extent through conscientious currently under consideration. There is a hope actions by States to control access to sensitive that such enhanced analysis capabilities not only materials and technology, to report transfers of will strengthen the Agency's verification sys- material and equipment to the IAEA, and to tem, but that, through their implementation in a express concerns when the actions of States ap- synergistic arrangement, the costs of verification pear inconsistent with normal peaceful nuclear may be limited without sacrificing effectiveness. programmes. Routine inspections of facilities which process, Various measures are being implemented to store, and use separated plutonium and HEU strengthen IAEA safeguards. While the specific currently account for approximately one-third of As part of verification elements of special inspections, provision and all IAEA inspections. Whether the enhanced activities, the IAEA verification of design information, and expanded analysis methods enable a reduction in the re- analyzes information on the status of reporting have received special attention, one of maining two-thirds, or in inspections at these safeguarded nuclear the most significant changes is the adoption of facilities, is not yet clear. O materials. "enhanced safeguards analysis" as a mechanism for complementing traditional verification mea- sures. The specific elements of "enhanced safe- guards analysis" are being defined, but certain directions already are evident. First, systematic reviews of information re- lated to the nuclear activities of States will be undertaken on a routine basis. The information will include design information and inspection data obtained in the normal course of IAEA safeguards implementation. Information from all facilities within a State, and from transaction partners in international commerce will be ex- amined. In addition, information from other de- partments of the IAEA will be collated to con- firm the safeguards data and to indicate inconsis- tencies that may suggest undeclared activities. Reviews of publications regarding the nuclear activities within a State also will be examined in a routine manner. Information provided by Member States in conjunction with recent recommendations by the IAEA Board of Governors also will be consid- ered in these Statewide reviews. This informa- tion includes expanded reporting of all nuclear

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