Safeguards Analytical Laboratories

To ensure the independence of the destructive analyses required by the safeguards system, the IAEA set up a Safeguards Analytical Laboratory as a part of its other Laboratories, adjacent to the Austrian Research Centre near the village of Seibersdorf some 30 kilometres south of Vienna. Here, a team of 20 scientists and technicians determine the concentration and isotopic composition of safeguarded nuclear materials by the analysis of samples taken at all stages of the nuclear fuel cycle, at some 56 nuclear facilities all over the world. 

Techniques applied at IAEA Safeguard Analytical Laboratory on Iraq samples... 

The ion source and collector pieces were from the large (1200 mm) calutrons which were declared to have been in operation at Tarmiya. These graphite pieces were scraped with a razor blade to remove about one gram of powder from the surface which was then leached in nitric acid to dissolve the uranium. This was followed by isotopic measurements using a mass spectrometer at Seibersdorf s Safeguards Analytical Laboratory. Results showed that the ion sources sampled for analysis contained only natural uranium (see table 11.11). The data from the sampled collector pieces show enrichments not exceeding about 6%. 

Some of the NDA verification techniques on samples of nuclear material taken during a safeguards inspection are carried out at specialized analytical laboratories, for example, the Safeguards Analytical Laboratory (SAL) at Seibersdorf in Austria or the On-Site Laboratory (OSL) at the Rokkasho Reprocessing Plant in Japan. Commercially available and customer-specific equipment is used to determine amounts and isotopic compositions of plutonium and uranium in inspection samples, having various chemical and physical forms, to supplement or replace destructive analysis. A parallel analysis of one and the same sample by NDA and DA serves the quality assurance of the analytical methods and control of the results. 

The concept of IAEA s safeguards analytical services (Lopez-Menchero et al. 1976) foresaw that the agency would establish and operate a fully equipped safeguards analytical laboratory (SAL). The analytical capability of SAL was to be such that samples taken from any key measurement point of the fuel cycle could be analyzed and that the results of these analyses would meet the requirements of safeguards accounting verification. 

Safeguards analytical laboratories use essentially the same sorts of techniques and equipment as research and plant laboratories for nuclear material isotopic and elemental assay and... 

The type of the safeguards agreement and facility, as well as all the above factors are taken into consideration when the safeguards approach for the particular facility is prepared. This approach will determine also the verification methods and the instruments that will be installed permanently at facilities and applied during inspections or used in the analytical laboratories on samples taken by the inspectors. 

The majority of the nuclear material samples, collected during safeguards inspections and sent to an analytical laboratory for measurements, serve several purposes, (i) They are taken to verify the correctness of declarations for the amounts of nuclear material (element (U, Pu, Th) and isotope amounts U)) in inventories and in transfers into or out of a facility,... 

To accommodate the 5,000 samples that were anticipated annually, SAL was to become part of a network of analytical laboratories (NWAL), along with existing laboratories nominated by member states for this purpose at the request of the IAEA. This approach was selected for reasons of economy and flexibility of services, but also because it provided the possibility of checking the accuracy of the analyses of actual inspection samples by comparing results obtained by different verification laboratories. Such an intercomparison was to become an important feature of the quality control program that the IAEA maintains to ensure the quality of measurements made by SAL and the network. Other safeguards systems operate in a similar way, which indeed strengthen the credibility of the verification measurements. After the successful completion of the PAFEX-1 and PAFEX-2 tests, IAEA NWAL became operational in 1975 (O Fig. 63.14). 

The hybrid K-edge densitometer (HKED) turned out to find quicker applications for safeguards verifications (Ottmar et al. 1986 Ottmar and Eberle 1991) at the input of spent fuel reprocessing plants, as the sample needs neither a dilution nor any treatment before measurement. The technique, considered as an NDA method and described in Sect. 63.3.1, is installed in particular in on-site analytical laboratories and operated by analytical chemists on duty there. Operators have found the instrument so practical and reliable that they use it in their nuclear material accountability program (Brousse et al. 1993). The HKED fluorescence channel is also used for DA of Th or mg-size Pu samples. 

SAL Safeguards Analytical Laboratoy. A particular radiochemical laboratory at IAEA Vienna. 

The IAEA collaborates with a number of laboratories in the member states that form a network dedicated to the analysis of environmental samples for safeguards. O Table 63.14 lists the members of this network and the analytical services they offer. 

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