Some Safeguards Considerations for a Reference Mixed Oxide Fuel Element Fabrication Plant with an Annual Throughput of 500 Kg PuO sub 2 . Final Report on the Advisory Group on Safeguarding Fuel Element Fabrication Plants.

摘要

Mixed Oxide (MOX) Fuel Element Fabrication Plants constitute some of the most sensitive facilities in the nuclear fuel cycle from the safeguards point of view as they handle nuclear material in bulk form which could be used directly for the manufacture of nuclear explosive devices. It will therefore be necessary to apply stringent safeguards measures to counter the abrupt and protracted diversion strategies which could be employed in such plants. In order to be capable to detect a protracted diversion a material balance closing with respect to Material Balance Areas (MBA) is required, combined with physical inventory taking, normally including halting of the process operations and collecting nuclear material at Key Measurement Points, conducted by the operator and verified by the Agency. Its frequency, which depends on many parameters, is specified in the facility attachments. This paper discusses one possible approach which is based on interim inventory verifications every two weeks, which do not coincide with closing a material balance and during which part or all of the inventory is verified. This means that the inventories of MBA's are verified at certain Strategic Points which can be accessed without interrupting the process operations, combined with a continual flow verification. This may provide the possibility of deriving a statement with respect to a possible abrupt diversion of nuclear material at a certain probability. (Atomindex citation 12:602712)