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Title: Fast Critical Assembly Safeguards: NDA Methods for Highly Enriched Uranium (Summary Report, October 1978 - September 1979)

Technical Report ·
DOI:https://doi.org/10.2172/7055095· OSTI ID:7055095
 [1];  [1]
  1. Argonne National Lab. (ANL), Argonne, IL (United States)

Nondestructive assay (NDA) methods, principally passive gamma measurements and active neutron interrogation, have been studied for their safeguards effectiveness and programmatic impact as tools for making inventories of highly enriched uranium fast critical assembly fuel plates. It was concluded that no NDA method is the sole answer to the safeguards problem, that each of those emphasized here has its place in an integrated safeguards system, and that each has minimum facility impact. It was found that the 185-keV area, as determined with a NaI detector, was independent of highly-enriched uranium (HEU) plate irradiation history, though the random neutron driver methods used here did not permit accurate assay of irradiated plates. Containment procedures most effective for accurate assaying were considered, and a particular geometry is recommended for active interrogation by a random driver. A model, pertinent to that geometry, which relates the effects of multiplication and self-absorption, is described. Probabilities of failing to detect that plates are missing are examined.

Research Organization:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
DOE Contract Number:
W-31-109-ENG-38
OSTI ID:
7055095
Report Number(s):
ANL-80-13(Vol.3); TRN: 81-002919
Country of Publication:
United States
Language:
English