DESIGN OF HEU TEST OBJECTS

The Nonproliferation Research & Development Office of the National Nuclear Security Administration (NA-22) recognized that there was a shortage of HEU sources with verifiable emission rate available for the testing of radiation detection equipment and that the use of the existing sources is prohibitively expensive due to safeguards requirements. Collaboration between ORNL and Y-12 has produced an HEU gamma source to address these concerns. The source has a gamma emission equivalent to a 2.5kg 90% enriched HEU solid sphere but contains less than 50g of HEU in an alloyed matrix which reduces its graded safeguards level from 2B to 4C. The source is spherically symmetric, which eliminates the need to include geometry corrections in test scenarios involving moving sources or detectors i.e. portals or search detectors. The source is qualified as an NRC sealed source which facilitates transportation. The source design and tooling is available to other government agencies so that they may produce duplicates at reduced cost. This talk will discuss the computer modeling and other considerations which led to the design of the source and the gamma emission of the final product.