Investigation On Radioactive Level Of Gauges Containing Sealed Radioactive Source In Xinjiang

Objective:To learn about the radiation dose level of the gauges containing sealed radioactive source in Xinjiang,the individual dose level and occurrence of the radiation accident so as to provide the data for the future supervision and management of gauges containing sealed radioactive and enhancement of safe radiation source management. Methods:To monitor the radiation level around the sealed radioactive source using BBL-81mrad meter,FJ-347χandγRadiation Doserate Meter,FD-3013B IntelligentizedγRadiation Meter and BH3105 Neutron Dose Equivalent Meter.To measure the individual dose of external radiation upon the radiation work staff by LiF(Mg,Cu,P) powder,GR-206A and GR-207A pellet through thermoluminescence detection using FJ-377 thermo luminescence reader,TOLEOO-654 England thermo luminescence reader, HW-Ⅱthermo luminescence annealing furnace.To evaluate the radiation dose level around radiation sources as per the national standard and analyze the key points of health safe.Results:The radiation dose level around gauges containing sealed radioactive sources was in accordance with the requirements of the national standard in Xinjiang.The average dose equivalent rate at the point 5cm and 1m from the surface of the source container was the highest using,Level meter and followed by neutron level meter,nuclear scale and others,and that of the thickness meter was the lowest.The air kerma rates on the surface of radiation source tank in logging,inside and outside the source transportation van,on the surface of protection cover of the radiation source pit and outer walls of the radiation source store room were qualified with the national standard.The qualified rate of neutron source pit was 93.75%.In 2002-2006,the individual dose equivalents per year among 95.63%of operators of gauges containing sealed sources were below 2mSv,ranged between 0.542 and 1.210 mSv·a-1.In 2005-2006,the individual external dose equivalents per year among 91.89%work staff of oil field logging were below 2mSv,ranged between 2.267 and 2.869 mSv·a^-1.The level of the personal external exposure dose to radiation was higher among work staff of the oil field logging than operators of gauges containing sealed sources.In 2002～2006,there occurred a radioactive accident,a responsible accident.In 1961～2006,there were 29 radioactive accidents,of them 26 were responsible accident,accounting for 89.66%.Conclusion:The radioactive dose level of gauges containing sealed radioactive source basically accorded with the national radiological protection standards in Xinjiang and the individual external dose equivalents per year of gauges containing sealed source and oil field logging far lower than the national standard value.So under the normal performance and maintenance,gauges containing sealed source were relatively safe for use.There were relatively more responsible accidents in Xinjiang,and the future key points of management of radioactive sources should be focused on building up the safety awareness.The supervision agencies for the radiation protection should enhance law enforcement of health and increases the frequency of the regular supervision to guarantee the proper use of radiation sources.