200 likes | 209 Views
Learn about radiation sources at abandoned mines, radiation measurement equipment, regulations and agencies, adopting safety standards, and problems faced. Ensure safety at abandoned uranium mines.
E N D
Presentation Overview • Radiation sources at abandoned mines • Radiation 101 (radiation for dummies) • Looking for guidance (regulations, agencies) • Adopting standards & protocols • Paper versus real world • Retrospect • Radiation measuring equipment we use • Problems so far
Radiation at abandoned uranium mines • Abandoned ore piles • Waste dumps • Mine portals (ore vein in ribs, roof) • Mine portal discharge • Mine workings (air)
Radiation 101 • Units of measure & terms • Roentgen – amount of ionization in air • Rad – radiation absorbed dose: energy deposited into some material • Rem – roentgen equivalent man: effective dose equivalent (biological risk of a radiation dose) • WL – working level: radon concentration (alpha)
Radiation 101-more- • Occupational worker: radiation exposure as a part of the work assignment • Non-occupational worker: everyone else, including the general public • NORM – naturally occurring radioactive materials • TENORM – technologically enhanced NORM
Looking for guidance • NRC – Nuclear Regulatory Commission regulates source material (uranium, thorium), special nuclear material & byproduct material made radioactive • DOE – Department of Energy provides radiation protection standards for DOE activities • EPA – Environmental Protection Agency standards for nuclear power operations, management & disposal of spent fuel, high level & transuranic waste, uranium & thorium mill tailings
Looking for guidance – continued - • OSHA – Occupational Safety & Health Administration applies to active uranium mine operations & milling or refining facilities • MSHA – Mine Safety & Health Administration applies to active underground uranium mines • Utah Division of Radiation Control regulates receipt, possession, use, transfer & disposal of radiation sources by a licensee • Other Agency or Group Health & Safety Plans
Other Health & Safety Plans • University of Utah radiation safety policy manual • Health Physics and Instrumentation Monitoring Plan of the Navajo Nation AML Reclamation Department, Division of Natural Resources, Window Rock, Arizona
Adopting Standards & Protocols • Use same general safety standards as non-uranium abandoned mines • Classify workers as “non-occupational” • Use NRC definitions & limits for public exposure • Use MSHA limits for radon exposure, respirators, and reporting requirements • Use quarterly TLD badges
Paper Protocol-versus-Actual Protocol • AMRP staff unfamiliar with radiation • Construction contractors unfamiliar with radiation • Environmental cleanup contractors see protocol as too lenient
Paper Protocol-versus-Actual Protocol • Required Health & Safety Training session before construction begins • No eating, drinking, chewing, smoking in exclusion zone (mine portal) • Starts strict, becomes less strict, then remind crew
Exposures so far • TLD badges since 1997 (7 years) • Five separate, one time, individual, quarterly, deep tissue exposures ranging from 10 millirem to 30 millirem. • Chest X-ray 15-30 millirem
Has it worked? • TLD badges show low exposures to AMRP staff • AMRP staff more educated about radiation • Contractors more educated about radiation • Other agency staff more educated • Exposures As Low As Reasonable Achievable (ALARA)
Equipment used by Utah AMRP • Wm. B Johnson & Associates, Inc. Model GSM-360 Micro R Meter w/tissue equivalent probe (γ) [not in use now] • Ludlum Model 19 Micro R Meters (γ) • Thomson Nielsen Instant Radon Progeny Meter (α) • Global Dosimetry Solutions, Inc. type 14 TLD badge for whole body exposures (γ)
Problems so far • TLD badge accounting, billing • Getting workers to wear & keep track of TLD badges • Educating non-miner construction crew about radiation and radon • Natural ventilation affecting radon readings based on the time of day • Changing closure design to deal with high gamma or alpha radiation