Test procedures for the radiation qualification of safeguards systems operating in nuclear radiation fields

Safeguards equipment, in particular, electronic systems designated for unattended operation, has to be designed and approved for failure-free operation under different environmental conditions, e.g. nuclear or ionising radiation. Irradiation testing has to be performed in order to ensure the safe and reliable use as well as long-term survivability of electronic safeguards equipment in radiation environments typically occurring in nuclear installations. If radiation survivability measures are established already in the design stage of an electronic module when appropriate components such as microprocessors are being selected the time delay and additional costs will be negligible. Hitherto, the International Atomic Energy Agency (IAEA) and the Euratom Safeguards Authority were missing agreed test procedures and criteria for the qualification of safeguards equipment. Therefore, guidelines were developed for the application of universal measurement methods in irradiation tests. The radiation environments were adopted as defined in the draft version 2.04 of the proposal "Common Qualification Test Criteria for New Safeguards Equipment". These criteria have been worked out jointly by IAEA and Euratom. Depending on the radiation level the tested equipment is categorised into three classes: standard, high class and special application. The paper addresses the physical background of permanent damage and temporary malfunction of electronic or photonic systems, the guidelines for nuclear radiation testing of safeguards equipment, the criteria applied, and the statistical methods to be used. Test techniques have been defined for irradiation testing and parts control which, if applied, provide assurance that each delivered system will meet the radiation requirements. Guidance is given for managing the tests and templates for each sort of irradiation test. A set of templates was designed for the complete test documentation. The present document draws upon existing test and measurement standards. The described test methods are independent of any specific safeguards system. These test procedures and criteria have to reviewed and, if necessary, revised according to the experience gained.