Year
2017
Abstract
A technical basis document for representative aerosol sampling was developed for the LANL RRFMC (Respirable Release Fraction Measurement Chamber). The RRFMC is a 20-foot tall, airtight chamber, for the drop testing of nuclear material storage containers. The publication “Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities” (DOE-HDBK-3010-94) is a well-documented handbook and it widely utilized at DOE sites. This handbook provides information on Airborne Release Fraction (ARF) and Respirable Release Fraction (RRF) for plutonium and uranium under various accident conditions. Although the ARF/RRF information in DOE-HDBK-3010-94 is based on experimental results, field conditions will always have variations compared to the listed experimental conditions in DOE- HDBK-3010-94. Consequently, direct measurements of ARF and RRF for accident conditions will be performed at LANL for typical storage container types. In anticipation of these tests, appropriate methods for accurate measurement of relevant physical quantities had to be developed and demonstrated. Real-time aerosol measurements of the RRF over a particulate size range of 0.5 to 20 µm AED (aerodynamic equivalent diameter) will be performed with a TSI Model 3321 Aerodynamic Particle Sizer. Representative mass samples of the ARF (i.e. including particles larger than 20 µm AED) will be collected with an open-faced filter holder. The locations for the real-time probe and for the filter holder were determined according to relevant portions from ANSI N13.1-2011 “Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities”. Implementation of the ANSI N13.1-2011 standard required velocity measurements, measurement of aerosol concentration profiles and calculations of the percent deposition of aerosol in transport lines (from the probe location to the particle counter). An MSP Inc. (Shoreview, MN) model M1520 aerosol generator provided size-specific oil droplets for characterizing aerosol concentrations.