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Table of Content

    20 July 2017 Volume 37 Issue 4
      
    Measurement of aerosol particle size distribution in gaseous effluents of Qinshan nuclear power plant
    Hou Jie, Li Hang, Shen Fu, Chen Xiaoqiu
    RADIATION PROTECTION. 2017, 37(4):  249-253. 
    Abstract ( 95 )   PDF (1220KB) ( 82 )  
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    Particle size distribution measurement of gaseous effluents from Qinshan nuclear power plant was carried out. The results showed that the Activity Median Aerodynamic Diameter (AMAD) for majority of the aerosol particles was below 1μm, while the total aerosol concentration varied with different type of the units. The work provides references for evaluating the effectiveness of the system of sampling for gaseous effluents in the stacks at nuclear power plant.
    Application of radiation field monitoring at Hefei Light Source Ⅱ
    Ren Guangyi, $\boxed{\hbox{Li Yuxiong}}$, Xu Shaofeng, Luo Zhifei, Li Weimin
    RADIATION PROTECTION. 2017, 37(4):  254-258. 
    Abstract ( 61 )   PDF (1429KB) ( 51 )  
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    The radiation monitoring system and beam loss monitoring system have been enhanced with the upgrade of linac and storage ring of Hefei Light Source Ⅱ (HLS Ⅱ). Besides equipment protection and personal safety protection, the new system was enabled with equipment diagnosis by gathering and analyzing information about accident time, position, operation parameters of equipment and information about radiation source, which facilitated the commissioning, maintenance and radiation protection of the facility.
    Establishment of calibration apparatus for DMC2000S electronic personal dosimeter
    Zhang Qiang, Zhu Aozheng, Zhang Jingbo, Liu Cai
    RADIATION PROTECTION. 2017, 37(4):  259-264. 
    Abstract ( 50 )   PDF (1032KB) ( 137 )  
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    Based on the irradiation and measuring hardware and software specified for the DMC2000S type X and Gamma electronic personal dosimeter, a calibration apparatus was established and used to calibrate the DMC2000S electronic dosimeters as an on-site reference calibration standard. Applying the standard measuring instrument transfer method, the calibration standard achieved the unit traceability via calibration. With the measurement range of 10 μSv—100 mSv, and the expanded uncertainty of 9.2% (k=2), the calibration apparatus satisfied the usage requirements as well as the calibration requirements stipulated by the regulation of JJG 1009—2006 “Direct reading X and Gamma personal dose equivalent (rate) monitor”.
    Tritium activity concentration levels in environmental water in Guangdong Province
    Wang Jiayue, Lin Qing, Zhou Ruidong, Li Qiaoqin
    RADIATION PROTECTION. 2017, 37(4):  265-273. 
    Abstract ( 82 )   PDF (1473KB) ( 354 )  
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    Tritium activity concentration levels in environmental water in Guangdong Province were surveyed between 2012 and 2013. The results showed that: (1) Tritium activity concentration levels of water vapor in the air, river water, and reservoir water were significantly higher than those in sea water and ground water (p<0.01). Tritium activity concentration level of water vapor in the air was higher than that of rainfall (p<0.05); (2) Tritium activity concentration levels of river water and rainfall correlated with that of water vapor in the air (The Pearson correlation coefficients were 0.655 and 0.637, respectively; p<0.01). Tritium activity concentration levels of reservoir water and river water were also affected by rainfall (The Pearson correlation coefficients were 0.444 and 0.440, respectively; p<0.1); (3) The survey results were consistent with historical data. The present tritium activity concentration levels in environmental water in Guangdong Province ranged from 0.081 to 0.69 Bq/L, which are close to pre-bomb levels; (4) Tritium activity concentration levels in environmental water around Daya Bay and Ling'ao nuclear power plants were about 5 to10 times higher than the rest of Guangdong Province.
    Study on infant ingestion dose caused by radioactive effluents from the normal operation of nuclear power plant
    Tao Naigui, Liu Zhanyang, Tao Yunliang
    RADIATION PROTECTION. 2017, 37(4):  274-279. 
    Abstract ( 60 )   PDF (1140KB) ( 28 )  
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    Due to the lack of the infant diet near nuclear power plant, the evaluation of radiation effects on infants caused by radioactive effluents from nuclear power plant is incomplete. With references to IAEA No.19 Report and ICRP Publication 95, the infant dose from ingestion of mother's milk was calculated in this paper. A generic infant solid food feeding diet was also provided. The result showed that the method of dose calculation in IAEA No.19 Report was less conservative and the calculated dose value was smaller, while the method in ICRP Publication 95 was more feasible and reasonable.
    Reduction of radon exhalation rate through soil modified with bentonite/lime powder
    Deng Huijuan, Xiao Detao, Qiu Shoukang, He Zhengzhong, Ju Zhihao, Xiao Feng
    RADIATION PROTECTION. 2017, 37(4):  280-286. 
    Abstract ( 91 )   PDF (1497KB) ( 98 )  
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    To compare the effectiveness of radon suppression with the addition of different proportions of bentonite or lime powder in soil, a standard module (35 cm×35 cm×12 cm) with a stable radon exhalation rate as the source term and a height adjustable experiment box with cross section of 30 cm×30 cm were used. The soil moisture content and degree of compaction were kept consistent during the experiment. The results showed the better suppression effect of radon with increasing proportions of bentonite or lime powder, while bentonite more effective in radon suppression than lime powder. The fitting lines showed the logarithmic relationship between radon suppression effect and covering thickness with different proportions of bentonite or lime powder. The logarithmic equation was obtained and the corresponding diffusion coefficient of radon was calculated. The relationship between the radon exhalation rate before covering and the thickness of covered soil has been deduced to meet the required management limit of 0.74 Bq·m-2·s-1, which could provide a conservative calculation for the covering thickness for the required surface radon exhalation rate. The economic comparison analysis showed that the cost for adding lower proportions of materials would be higher than the original soil, and vice versa. The cost would decrease with the increasing proportions of materials.
    Experience on ALARA management at Daya Bay NPP
    Lun Zhenming, Gao Xing, Li Bo, Huang Xinming, Sun huanyu, Yang Junwu
    RADIATION PROTECTION. 2017, 37(4):  287-292. 
    Abstract ( 142 )   PDF (1453KB) ( 137 )  
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    This paper introduces the ALARA system, practices and outcomes of radiation protection primarily with operating experience gained from the Daya Bay NPP, with respect to responsibility, organization, concept delivery, technology application, and process management etc. With the continuous improvements on the ALARA system applied at the Daya Bay NPP, the collective dose of 6 reactor units has decreased by more than 145 man·mSv (a comparison between September 2015 and January 2013) and would continue to decline.
    Evaluation on radiation protection in a uranium enrichment facility during trial operation
    Qing Qing, Ma Zhou, Li Ping
    RADIATION PROTECTION. 2017, 37(4):  293-297. 
    Abstract ( 60 )   PDF (1991KB) ( 141 )  
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    The radiation protection measures including partition, containment, flow organization and relevant managements on the fourth phase project of a uranium enrichment facility are described. The monitoring results including gaseous effluents, surface contamination, worker dose, uranium and fluoride levels in the urine samples of the workers were far lower than national standards and related control limits, demonstrating that the protection measures taken in the facility were effective.
    Study on adsorption performance of activated carbon for radioactive inert gases under different operating conditions
    Liu Yu, Niu Lijun, Li Yongguo, Tang Shaohua, Huo Ming, Shi Yingxia, Qiu Dangui, Wang Zhimin, Qiao Taifei, Wu Bo
    RADIATION PROTECTION. 2017, 37(4):  298-302. 
    Abstract ( 61 )   PDF (1869KB) ( 102 )  
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    Activated carbon adsorption technique is one of the options for treatment of radioactive inert gases in nuclear power plants. This paper described the adsorbing theory of activated carbon for radioactive inert gases Kr and Xe, along with its main physical parameters. The result of performance tests under different operation conditions showed that the dynamic adsorption coefficient of activated carbon would be influenced by temperature, pressure, flow velocity and humidity of the treated gases. Excessively high temperature and humidity, as well as low flow velocity would have negative effects on the dynamic adsorption efficiency, whereas increasing pressure would be beneficial to the dynamic adsorption. This research result could be helpful to the design of the treatment system for waste gases in nuclear power plants. With the operation conditions properly controlled, the adsorption performance of activated carbon can be assured.
    Screening of radiation protective constituents of Sijunzi Decoction
    Qu Gonglin, Shao Shuai, Li Chen, Tu Xumin, Wang Chunyan, Qi Xuesong, Tong Peng
    RADIATION PROTECTION. 2017, 37(4):  303-308. 
    Abstract ( 65 )   PDF (1490KB) ( 114 )  
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    The purpose of this research was to evaluate the radiation protective effects of different constituents of Sijunzi Decoction on BALB/c mice. One hundred and ninety two BALB/c mice aged 6—8 weeks were divided by random number table method into normal control group, model group, Sijunzi Decoction water extract group, alcohol extract group, and groups of the supernatant of 50%, 60%, 70%, 80% alcohol to precipitate of aqueous extract, respectively. Radiation-damaged mice model were single-irradiated by 3.5 Gy 60Co γ rays, and the extracts of Sijunzi Decoction were administered intragastrically before and after the irradiation. The activity index including peripheral hemogram, thymus index and bone marrow micronucleus rate were examined. The results showed that, compared to the radiation model group, the WBC counts of the group with the supernatant of 80% alcohol to precipitate of aqueous extract(p<0.05) were increased significantly at 3 d after irradiation, while the mice bone marrow micronucleus rates were obviously reduced by the water extract, alcohol extract and the supernatant of 50%, 60%, 70% alcohol to precipitate of aqueous extract(p<0.05). At 7 d after irradiation, the mice thymus indices were elevated in the groups with the supernatant of 70%, 80% alcohol to precipitate of aqueous extract(p<0.05), whereas the mice bone marrow micronucleus rates were reduced in the same way by the water extract, the alcohol extract as well as the supernatant of 60%, 70%, 80% alcohol to precipitate of aqueous extract(p<0.05). The largest reductions in the mice bone marrow micronucleus rates were observed in the groups of the supernatant of 70%, 80% alcohol to precipitate of aqueous extract. The above results indicate that the supernatant of 70%, 80% alcohol to precipitate of aqueous extract could possibly be the major radiation protective constituents of Sijunzi Decoction. This conclusion provides not only the basis for the studies on the anti-radiation chemical constituents of Sijunzi Decoction and on its anti-radiation effect mechanism, but also the scientific evidence for the new anti-radiation drug development in traditional Chinese medicine.
    Mechanism of radioprotection effects of Astragaloside IV on the liver cell
    Hu Yameng, Long Ying, Chen Kelian, Liu Bengbo, He Shuya, Huang Bo
    RADIATION PROTECTION. 2017, 37(4):  309-316. 
    Abstract ( 66 )   PDF (2814KB) ( 71 )  
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    The radioprotection effects and molecular mechanism of Astragaloside IV (ASIV) on the liver cell L-02 was studied. The experiments were conducted with four groups: the control group, the ASIV group, the irradiation group and the ASIV+irradiation group. The rate of apoptosis and cell cycle were detected by flow cytometry and Rhodamine-123 fluorescent probe was used to detect potential alternation of the mitochondrial membrane in L-02 cell. γH2AX foci were detected by immunofluorescence confocal microscopy while the expressions of Nrf2, HO-2, NQO1 proteins were observed by western blot method. The results showed that the apoptosis rate and the arrested cell cycle G2 decreased with increasing concentrations of Astragaloside IV after irradiation and the membrane potential increased with the rise of Astragaloside IV concentration as observed by spectrophotofluorimetry after Rh123 dyeing. The confocal microscopy results showed that the number of γH2AX focus in Astragaloside+irradiation group was significantly less than in the irradiation group. Western Blot results indicated that the expression of Nrf2, HO 1-and NQO1 increased in the irradiated cells, while the opposite trend showed in Astragaloside + irradiation group with increasing drug concentration.
    Monitoring and analysis of dose equivalent rate to hands and neck of the patients with thyroid cancer after iodine-131 therapy
    Yi Yupin, Zhu Yuquan, Duan Dong, Hu Fengqiong, Yan Yayun, Ye Xiangshuai
    RADIATION PROTECTION. 2017, 37(4):  317-321. 
    Abstract ( 100 )   PDF (1548KB) ( 51 )  
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    In order to optimize the protective measures for patients with differentiated thyroid carcinoma (DTC) after iodine-131 therapy, the variation of dose equivalent rate to hands and necks of the patients was monitored at short distance. 100 DTC patients were divided into two groups with 50 cases in each group. Group 1 was thyroid remnant 131I ablation therapy group (dose from 3 700 to 4 440 MBq), and Group 2 with 131I treatment for recurrent and metastatic lesions (dose from 6 660 to 8 140 MBq). To determine dose equivalent rate to hands and necks, an Inspector Alert gamma detector was used to measure the dose rate on discharge,and at one week,two weeks,one month and two months after discharge. The detector was placed 30 cm away from the necks and palms, and closely contacted skin, respectively. The results showed that: (1) All the measured dose rates were high at the time of discharge after iodine-131 therapy, and the dose rates gradually decreased over time. The dose equivalent rates measured 30 cm away from the necks and palms one month after discharge and all the results for two months after discharge were lower than 0.25 μSv/h. (2) At the time of discharge, average dose equivalent rates to the necks were higher than those to the hands(p<0.05), while at the time of one week, two weeks, one month after discharge (p<0.05), the average dose equivalent rates to the hands were higher than those to the necks. (3) Dose equivalent rates for Group 1 in front of the neck at the time of discharge and at one week, two weeks, one month after discharge were higher than the results of Group 2(p<0.05), while dose equivalent rates for Group 2 measured by closely contacting the hands were lower than those for Group 1 at the same time (p<0.05). As all the results for the DTC patients measured at the time of discharge were higher than 20 μSv/h, we recommend that the patients should avoid intimate contact with others within a week after discharge and also avoid long-time contacts within two weeks after discharge. The DTC patients can have normal social activities with other people around one month after a large doses of 131I therapy, but in accordance with the principle of optimization of radiation protection, they should avoid intimate contact with vulnerable groups (such as infants, young children and pregnant women, etc.). Two months after therapy, as dose equivalent rates would have dropped to the background level, there is no need to take any radiological protection measures. As dose equivalent dose rates to the hands could be high due to contamination, patients particularly with the second course of treatment should take radiological protection measures.
    Discussion on accident source term and emergency planning zone of ACP100
    Luo Feng, Li Guoqing
    RADIATION PROTECTION. 2017, 37(4):  322-326. 
    Abstract ( 115 )   PDF (1594KB) ( 247 )  
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    The influence of unique design of the ACP100 on the accident source term is analyzed. The applicability of alternative source term (AST), mechanistic source term (MST) and mixed accident source term are compared. Suggestions on determination of mixed source term and emergency planning zone of the ACP100 are given.
    Issues on the representativeness of sampling in environmental radiation monitoring
    Xia Yihua, Wang Shaolin
    RADIATION PROTECTION. 2017, 37(4):  327-336. 
    Abstract ( 69 )   PDF (2548KB) ( 112 )  
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    There has been increasing recognition that field sampling is very important and can be the main source of total variability in the results of environmental radiation monitoring. However, the problems in obtaining an unbiased samples with sufficient representativeness have been overlooked. With an intention to promote the developments and improvements on these issues, the related conceptual guidance on statistical sampling problems given by ICRU report No. 75 is introduced and a general overview about the representativeness of environmental sampling in the scenario of current Chinese practices is given.