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Title: Particle Release Experiment (PRex) Final Report

An experiment to release radioactive particles representative of small-scale venting from an underground nuclear test was conducted to gather data in support of treaty verification and monitoring activities. For this experiment, a CO 2-driven “air cannon” was used to release La-140 at ambient temperatures. Lanthanum-140 was chosen to represent the fission fragments because of its short half-life and prominent gamma-ray emissions; the choice was also influenced by the successful production and use of La-140 with low levels of radioactive contaminants in a Defence Research and Development Canada Field Trial. The source was created through activation of high-purity natural lanthanum oxide at the reactor of Washington State University, Pullman, Washington. Multiple varieties of witness plates and air samplers were laid in an irregular grid covering the area over which the plume was modeled to deposit. Aerial survey, a NaI(Tl) mobile spectrometer, and handheld and backpack instruments ranging from polyvinyl toluene to high-purity germanium were used to survey the plume. Additionally, three varieties of soil sampling were investigated. The relative sensitivity and utility of sampling and survey methods are discussed in the context of On-Site Inspection. The measurements and samples show a high degree of correlation and form a valuable set ofmore » test data.« less
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  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  2. National Security Technologies, LLC. (NSTec), Mercury, NV (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Technical Report
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org:
Country of Publication:
United States
radionuclide; On-Site Inspection; OSI; underground nuclear test; Nevada Nuclear Security Site; atmospheric test; vented nuclear test