Activities of the ESARDA Working Group for Techniques and Standards for Non-Destructive Analysis

Full text: ESARDA is the European Safeguards Research and Development Association. Among the various activities of the association, Working Groups are established to promote and undertake collaborative R and D and information exchange activities in various fields. The Working Group for techniques and standards for Non-Destructive Analysis (ESARDA NDA-WG) was established with the mission to provide the Safeguards Community with expert advice on Non Destructive Analysis methods, procedures, reference materials and on the performance of NDA methods, as stated in the Terms of Reference. The achievement of the above objective can be obtained through a series of tasks: 1. Maintain a list of NDA methods and instruments currently used or under development for accountancy and verification purposes. 2. Determine the reliability of NDA methods where possible with inter-comparison exercises of safeguards measurements. 3. Advise EURATOM and IAEA on the implementation of new and improved methods and advise on areas where R and D is needed. 4. Promote and coordinate R and D programs to fulfill safeguards and nuclear material management needs. 5. Promote the systematic and correct use of Reference Materials. 6. Assess and disseminate Performance Values for Uncertainties in NDA methods of nuclear material measurement. 7. Participate in the review, and promote the use of, International Target Values for uncertainties in measurements of nuclear material. 8. Consider sampling errors and sampling problems and their significance for NDA results. 9. Promote the use of internationally agreed definitions and terminology in the reporting of measurement results. 10. Assist in the development of new NDA methods in support of new safeguards requirements. 11. Promote cooperation with other working groups and the inspection authorities. 12. Collaborate with other working groups to develop comprehensive and integrated tools to fulfill new safeguards requirements. The paper will describe the major projects (ongoing or recently completed) undertaken by the NDA Working Group. In the field of general NDA Instrumentation the WG has participated to the redaction of the document on 'International Target Values 2000 for Measurement Uncertainties in Safeguarding Nuclear Materials'. Then the real performances of NDA instruments have been reviewed in the document 'Performance Values for NDA techniques applied to safeguards'. Another performance value document for NDA techniques applied to waste sentencing is in progress. Together with the C/S-WG, a joint document on 'Guidelines for developing Unattended Remote Monitoring and Measurement Systems' has been issued. Finally a collection of NDA instrument characteristics is going to be compiled in a data-base. In the field of gamma spectrometry several inter-comparisons have been organized, the last one was the Pu-2000 exercise, in order to assess the capabilities of this technique. This has recently found an important milestone in the organization of the Workshop on 'Gamma Evaluation Codes for Plutonium and Uranium Isotope Abundance Measurements by High- Resolution Gamma Spectrometry: Current Status and Future Challenges' held in Karlsruhe in November 2005. A large variety of uranium and plutonium spectra acquired during these exercises has been collected in the 'ESARDA U/Pu Spectra Library' available on the web for anyone who wants to use them to assess the performance of a spectra analysis code. The working group is currently organising an inter-comparison exercise of measurement techniques applied to the characterisation of plutonium in waste drums. A large interest is devoted to the application of Monte Carlo techniques to the numerical simulation of neutron counters. Three benchmark exercises have been carried out in the last years in order to assess the capabilities of Monte Carlo to reproduce the experimental data: one was on a simple geometry in order to analyse the influence of the main physical parameters, a second one on the real coincidence calculation for an active neutron collar and the third one o n a passive multiplicity counter. The WG is also redacting a 'Good Practice Guide in the use of Numerical Simulation in NDA'. (author)