STUDY OF RADIOACTIVITY EFFECT OF MINING AND UTILIZING BONE-COAL MINE ON ENVIRONMENT
Ye Jida 1) Kong Lingli 2) Li Ying 3) Zhang Liang 4) Jiang Shan 5) Wan Ming 3) Liu Hongshi 1) Zhu Jinqiu 4) Shi Jinhua 2) Chen Changhua 2) Zhang Zhengguo 5) 1) Environmental Radiation Monitoring Center of Zhejiang Province, Hangzhou, 310012; 2) Environmental Protection Science Institute of Wuhan City, 430022; 3) Environmental Monitoring Center of Jiangxi Province, Nanchang, 330029; 4) Environmental Monitoring Center of Hunan Province, Changsha, 410004; 5) Environmental Monitoring Center of Anhui Province, Hefei, 230061
The development and utilization of the bone coal is a man made activity that may bring a important effect on the environment around the mine and on radiation dose of public living in the mine area. The paper introduces investigation methods and main results about the pollution source term of bone coal, which was caused by mining and utilizing in Hubei, Hunan, Jiangxi, Zhejiang and Anhui provinces. The store amount of bone coal in five provinces is above 90% of the total store amount in our country. It was measured that the γ radiation level and the annual average concentration of 222 Rn indoors and outdoors in the bone coal mine areas in the five provinces. The specific activies of radionuclides in the bone coal, bone coal cinder, bone coal cinders brick et al. were analyzed. The additional dose to the public living in the bone coal cinder brick house and the other people working in the bone coal mine area was estimated. The investigation results showed that the mean specific activities of 238 U,226 Ra in the bone coal of the five provinces is 1.3 kBq/kg and 0.9 kBq/kg in the bone coal cinder brick, respectively. The mean specific activities of 238 U, 226 Ra in the soil of bone coal mine area are 0.37 kBq/kg and 0.24 kBq/kg, which are 8 times and 5 times highter than the average background value for the five provinces, respectively. The mean value of γ radiation dose rate and the annual average concentrations of 222 Rn in the bone coal cinder brick houses in the five provinces are 0.3 μGy/h and 0.15 Bq/m 3, respectively. The additional annual average doses, which are caused by γ radiation and potential alpha rays of 222 Rn in the bone coal cinder brick house indoors and outdoors of the five provinces, are 1 mSv and 3 mSv, respectively. The additional collective dose (50 years), which were caused by bone coal cinder brick house in 25 year, is some 1.5×10 5 person·Sv. Most of bone coal cinder might not be used in constructinal materials when its massic fraction is more than 20%.