NWAL SUPPORT TO IAEA SAFEGUARDS ANALYSIS P.Doherty, A.Zoigner, K.Sirisena and E.Kuhn IAEA Wagramerstrasse 5, A-1400 Vienna, Austria. 1/.

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1 IAEA-SM-367/5/03/P NWAL SUPPORT TO IAEA SAFEGUARDS ANALYSIS P.Doherty, A.Zoigner, K.Sirisena and E.Kuhn IAEA Wagramerstrasse 5, A-1400 Vienna, Austria. Abstract The IAEA maintains a Network of Analytical Laboratories that support the Destructive Analytical Services to the Department of Safeguards. These Network Laboratories fall into three categories: those which supply reference materials; those which supply analyses of Environmental Samples; and those which supply analyses of Nuclear Material Samples. Since 1995, the number of nuclear material samples analysed by the IAEA has declined, while the number of environmental samples has increased. It now appears that the sample throughput is constant at just over 1000 per year. Based on these changing sample requirements, the IAEA has increased the number of analyses performed by its environmental network laboratories and decreased the number of samples analysed by it's nuclear material network laboratories, while the need for provision of reference materials remains constant. This paper seeks to show the changes and general trends in the use of the network of analytical laboratories. 1/. INTRODUCTION The IAEA defines its Network of Analytical Laboratories (NWAL) as those laboratories/facilities that assist the IAEA in its destructive analytical services for nuclear safeguards. This assistance takes one of two forms: 1/. Reference Material Providers; and, 2/. Nuclear and Environmental Destructive Analyses Providers. Analytical services for IAEA safeguards take the form of Destructive Analysis (DA) of uranium and plutonium-containing materials for nuclear material accountancy, Environmental Sample (ES) analysis for detection of undeclared activities, provision of sampling materials, isotope spikes and Quality Control materials. These services have been achieved in collaboration with a Network of Analytical Laboratories (NWAL). The NWALs and Reference Material Suppliers provide recommendations to the IAEA (through the mechanism of regular Consultants Group Meetings) to improve and optimise the services, consistent with the identified requirements for accuracy, precision, reliability and timeliness. Some additional analytical services are now foreseen due to recent changes of safeguards requirements in nuclear fields. This paper focuses primarily on the work of the Nuclear Material NWAL, and some specific trends and needs in the services provided by the NWALs and Reference Material Providers are discussed below

2 2/. NEED 2.1 Reference Material Providers. The IAEA has a continuing need for high quality reference materials and, as such, maintains close co-operation with laboratories/facilities having the capability of supplying these. In many cases reference materials are made available through the relevant member state support programme. In other cases the IAEA purchases the materials. These providers do not constitute a network per se, but are used by the IAEA to obtain its reference materials. As such, the IAEA organises consultants group meetings every two or three years to: a/. review the current programmes of production of nuclear and environmental reference materials; b/. discuss the advantages and possibilities of collaborations on certifications and intercomparisons of nuclear and environmental reference materials; c/. identify future trends and problem areas in the needs and productions of nuclear and environmental reference materials; d/. make recommendations for future activities and development. 2.2 Nuclear Material & Environmental Analyses NWALs For the analyses of inspectionsamples, laboratories in different states have been certified to analyse samples on behalf of the IAEA. In general, the needs are threefold: 1/. Analyses of samples in parallel with SAL to maintain the state of readiness of the NWAL and to give additional assurance on SAL s results; 2/. To carry out analyses on behalf of SAL during periods of high sample throughput, or in those areas of analyses where SAL cannot provide an analytical service: 3/. To give added capability to the IAEA DA Service by carrying out analyses for which the IAEA does not have the capability. 3/. ACTIVITIES 3.1 Reference Material Providers. Since 1995, the IAEA has been supplied with reference materials for environmental bulk and particle analyses. These reference materials are mainly of the following types: bulk and particle reference materials for environmental swipe analyses; high purity separated plutonium isotopes; plutonium chemical standards; uranium isotopic mitures; plutonium isotopic mitures; actinide standards; impurity standards 2

3 3.2 Nuclear Material Analyses NWALs The IAEA currently maintains 7 Nuclear Material NWALs. Every two years or so a Consultant s Group Meeting (CGM) is held with the aims of reviewing the activities of the NWAL, the last CGM was held in October 2000 [1]. In particular the relevant quality control limits and the NWAL s performance against these is discussed. In the interests of discretion, each NWAL holds bilateral discussions with the IAEA on its own performance. Other issues of interest include the transport of safeguards samples, the future needs in analytical services and the current international target values. International Target Values 2000 [2] describe the state of the practice of nuclear analytical techniques in terms of the measurement uncertainties that should be achievable under practical routine conditions. This document represents the current control limits that are epected from the analyses of Nuclear Material Samples. Table 1 shows the number of samples analysed by year and by type and these data are represented graphically in graph 1. As can be seen, there was a reduction in the number of nuclear material samples received for DA analyses in the mid 1990s due to the implementation of new SG measures, although these numbers are now stabilised. In addition, the number of environmental samples has stabilised after the initial implementation in Table 1. No. of Samples analysed by Year and Type U Pu SF D2O 'Special' Env l Total

4 Graph 1 - DA Samples by Year & Type Sample no 'Special' D2O SF Pu U Year Table 2 shows the number of samples analysed by the NWAL during the period 1995 to 2000, and Table 3 shows these data as a percentage of total samples analysed. Looking at Graph 2 it can be seen that, although the initial trend was downward, by the end of the 1990s, the utilisation of the NWAL has stabilised. It should be noted that the relatively high use of miscellaneous laboratories in 1995 was necessitated by the need to send samples for special analyses in support of the IAEA Action Team Operations. Table 2. No of Samples analysed per year by the NWAL Lab Lab Lab Lab 4 5 Lab Lab Lab Misc 103 4

5 Table 3. Percentage of Nuclear Material Samples analysed per year by the NWAL Lab Lab Lab Lab Lab Lab Lab Misc 9.4 Total Graph 2 - % Inspection Samples Analysed at NWAL % total DA Samples Year Of the seven NWALs that were listed as active in 1995, it should be noted that only four remained active in One of the four inactive laboratories is epected to become reactivated in the near future, but nevertheless, the trend is of concern 3.3 Environmental Analyses NWALs Every year a Consultant s Group Meeting (CGM) is held with the aims of reviewing, among other things, the operation of services provided by the NWAL. These CGMs alternate with one year being devoted to particle analyses and the net to bulk analyses. The last CGM was held in October/November 2000 [3]. The participants invited to Consultants' Group Meetings are representatives of the laboratories that provide the main support in the 'bulk' or whole sample analysis of swipe samples from sampling mainly from hot cell facilities as well as in the development and further refinement of analytical techniques. CGMs serve to Review the operation of the services provided by the (NWAL), 5

6 Discuss the eperience collected in analysing these samples, and Provide recommendations that will lead to further improvements in the efficiency and effectiveness of the analytical services network. Table 4 gives the details of the number of environmental samples (and equivalent subsamples) that have been received since environmental sampling commenced in 1996, the number of subsamples sent to the NWAL and illustrates the output of the NWAL as a percentage of total environmental samples received. As some NWALs are still being certified, it remains to be seen how they will be utilised in the long run. Table 4. Environmental Samples Analysed at NWAL* Total No. of Samples Received Equivalent No. of Subsamples No. of Subsamples Dispatched to NWAL % of Samples Analysed by NWAL* * All environmental samples are radiometrically screened at SAL. Selected samples are then dispatched to the NWAL for further analyses. 4/. FUTURE NEEDS 4.1 Reference Material Providers. There is a continuing need for the regular supply of high quality reference materials. Such reference materials fall into two broad categories: commercially available materials and custom made materials. Reference materials can further be broken into two areas: environmental analyses reference materials and nuclear analyses reference materials. Thus there are continuing needs for such materials as: bulk and particle reference materials for environmental swipe analyses; high purity separated plutonium isotopes; plutonium chemical standards; uranium isotopic mitures; plutonium isotopic mitures; actinide standards; impurity standards. Additionally, there is also an ongoing need for IAEA-SAL to continue to participate in measurement evaluation programmes. 6

7 4.2 Nuclear Material Analyses NWALs Chemical and isotopic assays of U, Pu and D2O in nuclear materials and heavy waters will continue to be needed for the purpose of verifying the flows and inventories of materials declared under IAEA Safeguards. With the eception of D2O, and assuming that about 1000 samples are received annually for this purpose and that there is no abnormal pile-up or major failures of instruments or processes, SAL would be in a position to analyse them all in a timely manner. It is possible that some additional work, such as analytical requirements resulting from nuclear disarmament, those of Alternative Nuclear Materials and QC Support activities with respect to the On-Site-Laboratory (OSL) at Rokkasho in Japan may be epected, in spite of the fact that the focus of the workload on the destructive analytical service would be shifted gradually to the environmental analytical field, based on the implementation of strengthened safeguards. However, the continued need for Nuclear Material Analyses at the NWAL s is important in the following areas: to continue to analyse U, Th and Pu in a small fraction of the nuclear materials and QC samples in parallel with SAL to give additional assurance on the results of SAL; to be ready to be capable of analysing ANM; to be ready to respond quickly to urgent analytical requests of nuclear material samples in the case of problems at SAL; to continue to analyse all heavy water samples; to participate in the characterisation or validation of special samples and reference materials; to echange information on improvement of nuclear analytical techniques; to collaborate with IAEA-SAL when necessary to characterise nuclear/radioactive materials in the area of illicit trafficking. 4.3 Environmental Analyses NWALs The NWAL is needed to continue Bulk & Particle analyses etc. as requested by the IAEA and to periodically analyse QC Samples. The annual maimum number of samples which the respective laboratories can accept for the different types of analyses requested, is annually updated. Additionally, Analysis of QC Samples remains a priority for the continued assurance of quality from the NWAL. In 1996 environmental sampling in routine safeguards inspections commenced inside facilities under the eisting legal arrangements. Sampling under the additional protocol has commenced in certain states but is not yet in routine use, although more than

8 sub-samples from these sampling activities have been distributed to network laboratories for analysis. Wide Area Monitoring (WAM) is being considered in all aspects including type and number of samples and, when implemented, this may have an impact on the workload of the NWAL 5/. CONCLUSIONS It is clear that the number of DA samples received for analyses per year has stabilised since the late 1990s at around 1000 samples per year. This number of samples is not epected to decrease in the foreseeable future. Thus SAL will continue to have a need for high quality reference materials for the foreseeable future, and it is anticipated that this need will continue to be fulfilled either by commercial transaction or by the assistance of the Member State Support Programmes to IAEA Safeguards. D2O samples will continue to be analysed by the NWAL as will environmental samples. In the nuclear material analysis field, the NWAL will continue to be used for QC purposes and to alleviate the workload on SAL during periods of high throughput. Of the seven NWALs that were listed as active for analyses of Nuclear Material Samples in 1995, it should be noted that only four remained active in One of the four inactive laboratories is epected to become reactivated in the near future, but nevertheless, the trend is of concern As the need for analyses of alternative nuclear materials and wide area monitoring samples develops, the effects on the NWAL will become clearer and it may be that the analytical capabilities of the NWAL will epand to meet these challenges. 6/. REFERENCES [1] Consultants Group Meeting on Safeguards Analytical Services (Nuclear Material) and Quality Assurance Programme, th October Working Material & Conclusions and Recommendations [2] STR-327 International Target Values 2000 for Measurement Uncertainties in Safeguarding Nuclear Material. [3]Consultants' Group Meeting On Bulk Analysis For Environmental Samples 31 st October - 3 November

9 7/. APPENDIX - CURRENT NWALS AND REFERENCE MATERIAL PROVIDERS AND THEIR CAPABILITIES LABORATORY COUNTRY NUCLEAR MATERIAL HEAVY WATER REFERENC E MATERIAL PROVISION ENVIRON L PARTICLE ENVIRON L BULK AEA Technology UK * Harwell Atomic Energy Commission Laboratory (AECL) Chalk River Canada Air Force Technical Applications Center (AFTAC) USA Atomic Weapons UK Establishment (AWE) Bundesanstalt für Germany Materialforschung (BAM) CEA Laboratories France (Marcoule & Saclay) CEA Laboratories France * (Bruyeres la Chatel & Valduc) **DOE Network of Analytical laboratories USA Institute for Reference Materials and Measurements (IRMM) EU KFKI Atomic Energy Institute Hungary V.G. Khlopin Radium Institute (KRI) Russia Laboratory for Microparticle Analysis Russia 9

10 LABORATORY COUNTRY NUCLEAR MATERIAL HEAVY WATER REFERENC E MATERIAL PROVISION ENVIRON L PARTICLE ENVIRON L BULK DOE New USA Brunswick Laboratory (NBL) Netherlands Netherlands * Energy Research Foundation Nuclear Research Czech Rep. Institute (NRI) Defence UK Evaluation and Research Agency (DERA), Malvern Austrian Research Austria Centre Transuranium EU Institute (ITU) VTT Chemical Finland * * Technology Efpoo Japan Atomic Energy Research Institute (JAERI) Australian Nuclear Science and Technology Organisation (ANSTO) Safeguards Analytical Laboratory (IAEA) Japan * Australia * Austria * In the process of qualification ** DOE Laboratories are: Lawrence Livermore National Laboratory Los Alamos National Laboratory Oak Ridge National Laboratory Pacific Northwest National Laboratory Savannah River Technology Center 10