IAEA experience with authentication of in-plant NDA instrumentation

The paper discusses IAEA experience with permanently installed measuring equipment, i.e. in-plant NDA instrumentation, which often has advantages over portable equipment, such as improved accuracy, automated sample handling and data collection, and capacity for higher throughput. In some cases, in-plant equipment is the only means of making a field measurement. However, the use of in-plant equipment requires an additional set of inspector procedures to ensure that the instrument is working correctly and has not been tampered with. This process of verifying instrument performance is called authentication. General guidelines for approaches to authentication have been studied and formulated by an IAEA Advisory Group Meeting held in November 1981. Procedures for specific instruments have been developed in some cases with the help of national support programmes. The field application of authentication is accomplished by incorporating specific actions into inspection procedures. Results are written down as part of the working papers and included in the final inspection report. For quantitative checks such as measurement of a working standard the results are sent along with the inspection measurements to the Agency for inclusion in the safeguards data base. The in-plant equipment may be owned by the facility, a State, a safeguards organization or the Agency. In each case, the use of the in-plant equipment will necessitate additional interactions between facility operator and inspector, in order to judge the impact on plant operation, and understand what is being measured and what can go wrong. The paper discusses the IAEA's experience gained in the field application of authentication procedures for instrument systems such as weighing and volume measuring devices, rod scanners, neutron activation systems and K-edge densitometers