Year
2006
Abstract
Self-protection of nuclear material has been reviewed in the context of work efficiency and incapacitation. The problem of doing work in a transient state has been defined and a methodology has been provided that allows calculation of effectiveness degradation during task execution. An alternative approach to effectiveness degradation that looks at the problem in an end state of incapacitation is delineated and presented graphically. The relative abundance of materials from various types of research reactors is outlined. Cooling time to various levels of radiation has been calculated and is presented graphically. The dose rate of prevalent materials in storage at research reactor sites worldwide will fall below 100 Gy/h at ~2 h, ~100 h, and ~600 h for TRIGA, MTR, IRT-36, respectively. The current threshold dose rate for self- protection is 1 Gy/h (100 rad/h) at 1 m. A dose rate of 100 Gy/h (10,000 rad/h) at 1 m was determined to be the level that significantly affected performance and offered limited self-protection (in the range of minutes).