Safeguards inspection samples

Thermal ionization mass spectrometers (TIMS) with magnetic sector are thus the basic instruments for Pu and U isotopic analysis in safeguards inspection samples. The performance of commercial instruments has improved tremendously, particularly in the last 30 years, in terms of vacuum capability, design of the ionization source and detector assembly, stability of electrical supplies, sensitivity and linearity of ion current amplifiers, and includes full automatization of the measurement and data reduction. 

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,... 

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. 

Bulk Measurement, Sampling, Conditioning, and Shipment of Safeguards Inspection Sampies... 

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). 

Production equipment and machines fall under the safeguarding requirements of 29 CFR, Subpart O. OSHA requires the employer to conduct periodic inspections and ensure adherence to following proper procedures or requirements. This periodic inspection includes a review of each authorized worker s responsibilities under the energy control procedures. The inspections and the reviews provide a representative sample of compliance with the requirements of the standard and not a 100% inspection. 

Because safeguards systems cannot in practice cover all material during an inspection, the inspectors take only random samples of the total population for verification. The goal is to assure that the detection probability for detecting a defect (a falsified or missing item, a certain... 

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. 

For all samples collected during inspections, the analytical results and their evaluation will be reported to the corresponding state as part of an inspection statement. Any significant finding in the material balance evaluations will also be reflected in the annual Safeguards Implementation Report. 

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