SOURCE AND PATHWAY DETERMINATION FOR BERYLLIUM FOUND IN BECHTEL NEVADA NORTH LAS VEGAS FACILITIES

NEVADA, BECHTEL

BECHTEL NEVADA

关键词: Reactor Maintenance;    Security;    Monitoring;    Transport;    Engines;   

DOI  :  10.2172/861316
RP-ID  :  DOE/NV/11781--953
RP-ID  :  AC08-96NV11718
RP-ID  :  861316

美国|英语

来源: UNT Digital Library

【 摘 要 】

In response to the report ''Investigation of Beryllium Exposure Cases Discovered at the North Las Vegas Facility of the National Nuclear Security Administration'', published by the U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA) in August 2003, Bechtel Nevada (BN) President and General Manager Dr. F. A. Tarantino appointed the Beryllium Investigation & Assessment Team (BIAT) to identify both the source and pathway for the beryllium found in the North Las Vegas (NLV) B-Complex. From September 8 to December 18, 2003, the BIAT investigated the pathway for beryllium and determined that a number of locations existed at the Nevada Test Site (NTS) which could have contained sufficient quantities of beryllium to result in contamination if transported. Operations performed in the B-1 Building as a result of characterization activities at the Engine Maintenance, Assembly, and Disassembly (EMAD); Reactor Maintenance, Assembly, and Disassembly (RMAD); Test Cells A and C; and the Central Support Facility in Area 25 had the greatest opportunity for transport of beryllium. Investigative monitoring and sampling was performed at these sites with subsequent transport of sample materials, equipment, and personnel from the NTS to the B-1 Building. The timeline established by the BIAT for potential transport of the beryllium contamination into the B-1 Building was from September 1997 through November 2002. Based on results of recently completed swipe sampling, no evidence of transport of beryllium from test areas has been confirmed. Results less than the DOE beryllium action level of 0.2 ???g/100 cm2 were noted for work support facilities located in Area 25. All of the identified sites in Area 25 worked within the B-1 tenant's residency timeline have been remediated. Legacy contaminants have either been disposed of or capped with clean borrow material. As such, no current opportunity exists for release or spread of beryllium contamination. Historical records indicate that there are locations at the NTS which contain hazardous quantities of beryllium; however, because beryllium was not always considered a contaminant of concern, complete characterization was not performed prior to remediation efforts. Today, it is not practical to characterize Area 25 for beryllium due to the successful remediation. Analysis of sample data collected in B-1 for the BIAT was performed for the purpose of confirming past results and identifying a source of beryllium through the use of markers. The results confirmed the presence of man-made beryllium contamination in the B-1 High Bay at levels consistent with the NNSA Report. No source markers were found that would be associated with NTS historical nuclear rocket or weapons-related operations. Beryllium contamination was identified in the southwest area of the B-1 High Bay in characteristic association with materials handled during historic metal-working operations. Use of source marker analysis suggests a contributor of beryllium found in carpeted areas of the B-Complex may be naturally occurring. Naturally occurring beryllium is not regulated by Title 10 Code of Federal Regulations Part 850 (10 CFR 850) (see Appendix A). No current uncontrolled beryllium source or transport pathways have been identified as available for spread of contamination to uncontrolled areas from the NTS.