MEASUREMENT AND SIMULATION CALCULATION FOR SEVERAL IMPORTANT PERFORMANCES OF H P (10) SECONDARY STANDARD IONIZATION CHAMBER
WEI Yingjing1, AN Shifeng2, XIE Wenming2, FENGMei1, ZHANG Qingli1, and YI Hengguan1
(1. China Institute for Radiation Protection, Taiyuan 030006; 2. Liaoning Hongyanhe Nuclear Power Co., Ltd., Liaoning Dalian 116319)
Abstract: The structure and technical characteristics of T34035 H p (10) secondary standard ionization chamber are introduced. The calibration coefficient N H and correction factor k(R, α) of H p (10) secondary standard ionization chamber are measured. The uncertainty of the calibration coefficient N H is 4.6% (k = 2), and the uncertainty of the correction factor k (R, α) is 6% (k = 2). When the radiation incident angle is less than 75 degrees, the energy response is better than ±20% in the range of 12 keV – 1 250 keV, and the non-linearity of personal dose equivalent rate is better than ±3% in the range of 100 μSv/h – 3 Sv/h. The k(R,α) values of some narrow spectrum N series and low air specific kinetic energy L series are simulated by MCNP5. The results show that the error between the calculated value and the measured value is within the range of ±6%. The ionization chamber meets the requirements of the secondary standard ionization chamber and can be used directly for the transmission of H p (10) value.
Key words: H p(10) secondary standard ionization chamber; calibration factor N H; correction factor k(R, α)
Radiation Protection, 38(6):449–456, 2018
INVESTIGATION ON WEAK PENETRATION RADIATION OF VALVES IN QINSHAN PHASE II NUCLEAR POWER PLANT
WANG Chuan1, WEI Yingjing2, NI Wei1, LIU Liye2, CHEN Chenxiang1, and CAO Qinjian2
(1. CNNC Nuclear Power Operations Management Co., Ltd., Zhejiang Haiyan 314300; 2. China Institute for Radiation Protection, Taiyuan 030006)
Abstract: The radiation sources and weak penetration radiation of the main valves in four systems of the RCP, RRA, RCV and PTR are monitored during the eight outages in Qinshan phase II nuclear power plant. 110mAg is the main radioactive nuclide measured in valve deposition of RCV system. 58Co, 60Co, 95Nb, 95Zr, 51Cr and other radionuclides are deposited in valves of RCP, RRA and PTR systems. The associated β ray energy is mainly in the range of 500 keV. The Ḣ *(10), Ḣ '(0.07) and Ḣ '(3) are measured for four types of valves. The value of Ḣ '(3) /Ḣ *(10) is about 1.24, and the value of Ḣ '(0.07) /Ḣ *(10) is about 14. According to the measurement results, monitoring of eye lens and skin dose for maitenance workers in some key valves are suggested.
Key words: nuclear power plant; valve; radiological; weak penetration radiation
Radiation Protection, 38(6):457–465, 2018
FACTORS AFFECTING DETECTION LIMITS OF AEROSOL SAMPLING IN FANGCHENGGANG NUCLEAR POWER PLANT
HOU Jie1, LI wenting1, HUANG Li1, HAN Shanbiao1, GAO Yuzhong2, WANG Ruiying1, LI Li1, LI Bing1, YUE Huiguo1, and CHEN Xiaoqiu1
(1. Nuclear and Radiation Safety Center, Ministry of Ecology and Environment, Beijing 100082; 2. Fangchenggang Nuclear Power Station Co., Ltd., Guangxi Fangchenggang 538001)
Abstract: The low limit detection (LLD) and the influencing factors for air effluent sampling monitoring in first stage of Fangchenggang nuclear power plant was studied. The LLD of different radioactive isotopes in air effluent with certain relative standard deviation under certain confidence level was calculated. The relationship of the relative standard deviation varying with net counting rate in different counting time was analyzed. The results showed that only when the radioactive release of air effluent approached to the calculated level, the air effluent monitoring was able to get a meaningful outcome. The analysis provides a reference for other nuclear power stations to make their own air effluent monitoring program.
Key words: Fangchenggang NPP; air effluent; low limit detection; aerosol sampling system
Radiation Protection, 38(6):466–470, 2018
APPLICATION OF COMPUTATIONAL FLUID DYNAMICS METHOD IN THE ANALYSIS OF REPRESENTATIVE AEROSOL SAMPLING IN THE PIPELINE OF NUCLEAR FACILITY
WANG Xie, REN Zhongguo, and XIONG Zhonghua
(Insititute of Materials, China Academy of Engineering Physics, Sichuan Jiangyou 621907)
Abstract: The representative sampling of radioactive gases and aerosols determines the accuracy of environmental monitoring and evaluation results of nuclear facilities. The gas pipeline flow field was simulated with CFD (Computational Fluid Dynamics, CFD). The results were compared with the requirements in ISO 2889. It shows the current sampling position does not meet the requirements described in ISO 2889. The proper positions which can facilitate effective monitoring of radioactive effluents and provide scientific data support to environment evaluation are recommended.
Key words: computational fluid dynamics; sampling position; airborne effluent; sampling representation
Radiation Protection, 38(6):471–479, 2018
EVALUATION OF PROTECTION PERFORMANCE AGAINST WEAK PENETRATION BY SOME PERSONAL PROTECTIVE EQUIPMENT
WEI Yingjing1, ZHAO Pengfei2, NI Wei2, WEI Xiaofeng1, LIi Hua1, and LIU Liye1
(1. China Institute for Radiation Protection, Taiyuan 030006; 2. CNNC Nuclear Power Operations Management Co., Ltd., Zhejiang Haiyan 314300)
Abstract: In order to identify the protection effect of personal protective equipment on different energy β rays, the protection effects of personal protective equipment on Ḣ'(0.07) and Ḣ '(3) under various combinations of different energy β radiation fields were measured in 85Kr and 90Sr-90Y standard β radiation fields. During the outage of the nuclear power plant, the weak penetrating radiation protection effect of personal protective equipment on some positions was measured. The results show that the protective effect of personal protective equipment on field radiation is different because of the different β/γ value of the surface of the equipment being measured. Especially in the places with strong γ rays, the protective effect of personal protective equipment on Ḣ '(0.07) and Ḣ '(3) is generally poor, while the protective effect of protective glasses against weak penetration radiation is rather significant. It is suggested that workers should wear protective glasses in high energy β radiation field to reduce the dose of lens. Due to the poor protective effect of personal protective equipment on high-energy β radiation, the monitoring methods and protective measures for workers working in high-energy β radiation sites are given.
Key words: β ray; attenuation ratio; Ḣ '(0.07); Ḣ '(3)
Radiation Protection, 38(6):480–485, 2018
IMPACT ANALYSIS OF METEOROLOGICAL DATA FORECAST ON TRAJECTORY MIGRATION IN ATMOSPHERIC TRANSPORT PROCESSES
ZHANG Junfang1, LU Minghua1, YAO Rentai1, QIAO Qingdang2, and ZHANG Fang1
(1. China Institute for Radiation Protection, Taiyuan 030006; 2. Nuclear and Radiation Safety Center, Ministry of Ecology Environment, Beijing 100082)
Abstract: Statistical analysis of trajectory migration simulation results from different types of data and different spatial resolution level were carried out with three different types and different basic spatial resolution meteorological data i.e. NCEP reanalysis data, NCEP forecast data and ECMWF reanalysis data from January to December in 2013. The conclusion shows that different sources and different spatial resolution meteorological data have certain correlation, though it is weak, with the average horizontal migration deviation of the end of trajectory greater than 50%. Different sources of meteorological data with same spatial resolution have better correlation in trajectory migration simulation. The average horizontal migration deviation of the end of trajectory is less than 20%. The long-term accumulation of different source of global weather forecast and reanalysis products are significantly important to the study on trajectory migration in atmospheric transport simulation.
Key words: trajectory migration; atmospheric transport; meteorological data; spatial resolution
Radiation Protection, 38(6):486–495, 2018
STUDY ON METHODS AND INFLUENCE FACTORS OF MECHANICAL LEAKAGE TESTS FOR IODINE ADSORBERS
LIANG Fei, ZHANG Jirong, ZHANG Yuan, ZHANG Chongwen, and ZHANG Zhaochen
(China Institute for Radiation Protection, Taiyuan 030006)
Abstract: The applicability of several tracer gases for performance tests of iodine adsorbers were studied. Tracer gases investigated are trichlorofluoromethane (R-11), 1,1,1,2,2,3,4,5,5,5-decafluoro-pentane (Vertrel-XF), perfluoromethycylcopentane (PMCP), perfluoromethycyclohexane (PMCH), and perfluorodimethylcyclohexane (PDCH). Desorption behaviors of tracer gases from activated carbon affected by molecular weight, boiling point, temperatures, air velocity, moisture, water content of activated carbon were studied. R-11 was used in measuring mechanical leakage rates of iodine adsorbers at different levels of moisture loading. Meanwhile desorption efficiency of activated charcoal bed were measured after R-11 injection. Results show that the above alternative substitute gases (tracers) all meet the six criteria in Non-Mandatory Appendix TA-C of AG-1: Substitute Gas and Aerosol Substitute Selection Criteria. R-11 exhibited minimal desorption from activated carbon at less than 20% relative humidity of gas stream and 15% water content of activated carbon. Its result was more accurate. R-11 is now generally used in domestic nuclear power plants to measure mechanical leakage rates of iodine adsorbers.
Key words: tracer gas; leakage rate; desorption
Radiation Protection, 38(6):496–501, 2018
STUDY ON SHIELDING MATERIAL (SANDS) FOR DISUESD HIGH ACTIVITY RADIOACTIVE SOURCES CONDITIONING
SHEN Fu, YAO Zeen, YANG Weibing, LIANG Dong, MA Yinghao, AN Hongxiang, FAN Zhiwen, and ZHOU Jinyuan
(1. China Institute for Radiation Protection, Taiyuan 030006; 2. Lanzhou University, Lanzhou 730000 )
Abstract: Shielding experiment devices were established for high activity disused radioactive sources conditioning study. The shielding performance of different types of Xinzhou sands with different particle size and different density as well as different water contents were studied for engineering application. The suitable sands were chosen for high activity disused radiation sources conditioning. Results show that the dose rate will be controlled below 0.03 mSv/h by using 150 cm Xinzhou water-saturated sands for construction as shielding material while conditioning 1 000 Ci 60Co radioactive source.
Key words: high activity; spent radioactive source; conditioning; shielding; sands; density
Radiation Protection, 38(6):502–506, 2018
THE DEVELOPMENT OF REAL-TIME ASSESSMENT SYSTEM FOR NUCLEAR EMERGENCY AT URANIUM ENRICHMENT FACILITIES
JIA Linsheng, ZHANG Jiangang, FENG Zongyang, SUN Shutang, TANG Rongyao, YANG Yapeng, LI Guoqiang, and XU Xiaoxiao
(China Institute for Radiation Protection, Taiyuan 030006)
Abstract: The paper introduces the first integrated real-time assessment system for nuclear emergency at uranium enrichment facility in China. The system can assess the radiation effects of nuclear criticality accidents and UF6 leakage accidents in a real-time manner. It estimates nuclear criticality fission number according to the readings of γ alarm dose rate instrument, and automatically assess the nuclear criticality consequence. Focusing on the heavy gas characteristic of UF6 plume, the system combines the heavy gas model with the Gaussian model, thus simulates more accurately the UF6 diffusion process. The development of the system solves the problem of lacking the technical support capability for uranium enrichment facility in emergency preparedness and response.
Key word: uranium enrichment facility; nuclear emergency assessment system; protective action
Radiation Protection, 38(6):507–510, 2018
EXPERIMENTAL STUDY ON INFLUENCE OF MONTMORILLONITE CONTENT ON EXPANSION BEHAVIOR OF BENTONITE
LIU Wei1, LIANG Dong1, YANG Zhongtian1, MAO Haijun2, LIHonghui1, JIA Meilan1, ZHAO Shuaiwei1, and MAO Liang1
(1. China Institute for Radiation Protection, Taiyuan 030006; 2. Institute of Rock and Soil Mechanics of Chinese Academy of Sciences, Wuhan 430071)
Abstract: In order to find out the influence of montmorillonite content on swelling behavior of bentonite, the swelling pressure is tested using home-made equipment. Results show that, under experimental conditions, the indexes (maximum axial swelling pressure and radial swelling pressure) increase with the increase of montmorillonite content, and there is a linear relationship between the indexes and montmorillonite content. The maximum radial and axial swelling pressure were up to 2.03 MPa and 2.25 MPa respectively and their ratio was 0.902, for the sample of 70% montmorillonite content. The experimental results can provide reference for design of bentonite in geological disposal.
Key words: swelling pressure; montmorillonite content; bentonite; geological disposal
Radiation Protection, 38(6):511–516, 2018
DETECTION AND ANALYSIS OF MXR7 GENE EXPRESSION IN HUMAN LIVER CELLS INDUCED BY RADIATION AND PERIPHERAL BLOOD OF RADIATION WORKERS
DANG Xuhong1,2, ZUO Yahui1*, WANG Fang3, ZHANG Jingyun1, DONG Juancong1, ZHANG Zhongxin1, and DUAN Zhikai1
(1. China Institute for Radiation Protection, Taiyuan 030006; 2. China institute of atomic energy, Beijing 102413; 3. Heping Hospital affiliated to Changzhi Medical College, Shanxi Changzhi 046000)
Abstract: In order to explore the changes of MXR7 genes expression in human liver cells HL-7702 and peripheral blood induced by radiation, the expression changes of MXR7 gene in human liver cells irradiated by 60Co γ-ray were detected by real-time fluorescent quantitative PCR. Furthermore, MXR7 gene expression levels were detected in peripheral blood from radiation workers. Results showed that ionizing radiation can induce the change of MXR7 genes expression in human liver cells, and it is dose-related. The expression of MXR7 gene in peripheral blood from radiation workers was up-regulated to compare with the expression of non-radiation workers.
Key words: human liver cell HL-7702; radiation workers; MXR7 gene; ionizing radiation; peripheral blood
Radiation Protection, 38(6):517–521, 2018
INVESTIGATION ON RADIATION PROTECTION SITUATION FOR NUCLEAR MEDICINE IN CITIES OF EASTERN CHINA
TANG Bo1,2, WU Wenwei1,3, and TU Yu1
(1. School of Radiation Medicine and Protection, Medical School of Soochow University, Jiangsu Suzhou 215123; 2. Center for Disease Control and Prevention, Shandong Province, Jinan 250014; 3. Center for Disease Control and Prevention, Suzhou Hi-Tech Zone, Jiangsu Suzhou 215000)
Abstract: Most of the current investigations on radiation protection for nuclear medicine in China were limited to a single medical institution or a small-scale area. The conclusions obtained were rather one-sided. To be more comprehensive and representative, a total of 28 medical institutions in 7 provinces/municipalities in the eastern part of China were selected and a field research on nuclear medicine departments were conducted in our study. We investigated the following aspects in 28 hospitals including site setting, equipment configuration, sources of radionuclide, site monitoring and current status of radiation protection management. It was found that some hospitals had problems in unreasonable site selection, poor equipment condition and imperfect performance testing. More attention should be paid to such problems in future radiation protection and supervision work while corresponding solutions should be proposed too.
Key words: nuclear medicine; radiation protection; status investigation
Radiation Protection, 38(6):522–528, 2018