Legal Disclaimer: The authors are members of the Technical Staff of the Defense Nuclear Facilities Safety Board (Board). The views expressed are solely those of the authors, and no official support or endorsement of the article by the Board or the Federal Government is intended or should be inferred. An inadvertent nuclear criticality accident is one of the most serious accidents that can occur during decommissioning. As decommissioning programs go forward, continued vigilance must be maintained to ensure that an inadvertent criticality accident does not occur. After the bulk inventories of fissile material are removed from a fissile material processing facility it is still possible to have a nuclear criticality accident with the holdup fissile material remaining in the processing equipment. Holdup is usually determined by nondestructive assay techniques, such as, gamma spectroscopy, neutron counting, and calorimetry. A larger trained staff of assay scientists and technicians, compared to the staff for production operations, is required to implement these assay techniques in a timely manner to support D&D operations.
展开▼
