Radiological assessment of petroleum pipe scale from pipe-rattling operations.

摘要: Petroleum pipe scale, consisting of concentrated inorganic solids such as barium sulfate, can deposit on the inside down-hole pipes during normal course oil field pumping operations. A portion this scale has been shown to contain naturally occurring radioactive materials (NORM), predominantly compounds radium. When these are removed from well, there is a potential for radiation doses workers handling pipes, especially cleaned reuse. thorough sampling and measurement protocol was applied under variety weather conditions in an outdoor laboratory obtain accurate indication radiological aerodynamic characteristics release dust dispersion petroleum removal out-of-service with restored, historically relevant pipe-cleaning machine. Exposure rate data were also obtained both pre-cleaned general area inhabited by descaling operation. Four exposure pathways investigated: inhalation generated rattling, incidental ingestion dust, external uncleaned dispersed ground. Pipes three fields rattled collect much industry-representative possible. The Ra specific activity ranged 33.6 +/- 0.4 65.5 0.7 Bq g, depending formation. median atmospheric loading 0.13 mg m measured operator breathing zone. respirable fraction observed be about 42% 46%. Based cleaning 20 per day,250 d year average, annual committed effective helper 0.11 mSv (11 mrem) 0.45 mSv(45 19 microSv (1.9 97 (9.7 ingestion. Worker dose racks 0 0.28 (28 mrem). In deposition experiment, more than 99% weight deposited fell within 2 machine centerline, vast majority which downwind direction. material dominated worker estimates. estimated 2.8 (280 4.1 (410 helper.