Determination of Airborne Release Fractions from Loose Powder Contamination Under Impact Stress

Safety basis calculations support the safety considerations necessary for legacy nuclear facilities as they transition from active use, through limited operations and standby modes, until final disposition is achieved. Many of the calculations are governed heavily by the coefficients presented in DOE-HDBK-3010 in the form of airborne release of radioactive material resulting from penetration of the facility per seismic activity, full facility fires, and/or explosions. The main objective of this study is to validate the original data for airborne release fractions (ARFs) for powder contaminants under impact, as determined in DOE-HDBK-3010. The limited data available for impact experiments was generated at the Rocky Flats Plant in 1987, where the median ARFs for surrogate powder contamination were 4E-4 with a bounding value of 1E-2. However, estimating the level of uncertainty was challenging in the absence of multiple measurements conducted under identical test conditions. Moreover, the uncertainty was significantly increased due to the restricted range of the test conditions.