Summary of Surface Swipe Sampling for Beryllium on Lead Bricks and Shielding

Paik, S Y ; Barron, D A

关键词: BERYLLIUM;    BRICKS;    CONTAMINATION;    DEPLETED URANIUM;    DOSE RATES;    EXPLOSIVES;    RADIATIONS;    RADIOACTIVE MATERIALS;    RADIOACTIVITY;    RELEASE LIMITS;    SAMPLING;    SHIELDING;    SHIELDING MATERIALS;    SURFACE CONTAMINATION;   

DOI  :  10.2172/1022915
RP-ID  :  LLNL-TR-491914
PID  :  OSTI ID: 1022915
Others  :  TRN: US1104491

美国|英语

来源: SciTech Connect

【 摘 要 】

Approximately 25,000 lbs of lead bricks at Site 300 were assessed by the Site 300 Industrial Hygienis tand Health Physicist for potential contamination of beryllium and radiation for reuse. These lead bricks and shielding had been used as shielding material during explosives tests that included beryllium and depleted uranium. Based on surface swipe sampling that was performed between July 26 and October 11, 2010, specifically for beryllium, the use of a spray encapsulant was found to be an effective means to limit removable surface contamination to levels below the DOE release limit for beryllium, which is 0.2 mcg/100 cm{sup 2}. All the surface swipe sampling data for beryllium and a timeline of when the samples were collected (and a brief description) are presented in this report. On December 15, 2010, the lead bricks and shielding were surveyed with an ion chamber and indicated dose rates less than 0.05 mrem per hour on contact. This represents a dose rate consistent with natural background. An additional suevey was performed on February 8, 2011, using a GM survey instrument to estimate total activity on the lead bricks and shielding, confirming safe levels of radioactivity. The vendor is licensed to possess and work with radioactive material.