Table of Content

20 September 2016 Volume 36 Issue 5

  

A method of measurement of ultra-trace level Pu isotopes in soil and sediment samples by ICP-MS

Ni Youyi, Bu Wenting, Hu Dan, Xu Hong, Wu Yucheng, Guo Qiuju

RADIATION PROTECTION. 2016, 36(5):  265-271. 

Abstract ( 32 )   PDF (693KB) ( 39 )  

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As a widely accepted method of measuring ultra-trace level Plutonium isotopes in environment samples, the most difficulty and inaccuracy of ICP-MS measurement is from the interference of matrix elements, mainly uranium. In this research, we employed acid digestion and a two-stage anion chromatography for extraction and purification of Pu from soil and sediment samples, which can achieve high decontamination factor of uranium up to 1.5×10⁵. By introducing a APEX-IR sampling system combined with a Spiro membrane desolvation unit, the yields of polyatomic interferences ²³⁸U¹H⁺and ²³⁸U¹H⁺₂, which are the main interferences of ²³⁹Pu and ²⁴⁰Pu, are as low as 3.4×10^-5 and 7.6×10^-6, respectively. In case of using this method to analyze the Pu level of Chinese soils and sediments, the relative tolerances of measured results are supposed to be less than millesimal. The detection limit of this method for ²³⁹Pu and ²⁴⁰Pu are respectively 3.6 fg/mL and 7.3 fg/mL. This method is validated by analyzing soil and sediment reference materials IAEA-soil-6 and NIST-4357, both the ^239+240Pu concentration and ²⁴⁰Pu/²³⁹Pu atom ratio correspond well with the certified values.

Investigation of shielding system of radioactive water filters in nuclear power plant

Xue Feng, Zhao Yanpeng, Chen Bin, Lv Jun

RADIATION PROTECTION. 2016, 36(5):  272-278. 

Abstract ( 26 )   PDF (1373KB) ( 15 )  

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Combining with the characteristics of the 11^th filter of the Reactor Boron and Water Makeup System (REA011FI), the design and practice of installing fixed boron shielding equipment were discussed. The application of such equipment in LHNP had been proved practicable that the dose rate in the room which REA001FI located had decreased almost 80% and the collective dose of a single unit had reduced approximately 13.44 man·mSv/a, and it is a good practice in application of radiation protection ALARA principle.

Simulation study on diffusion of smoke cluster from dirty bomb explosion in subway station

Duan Zhongshan, Yuan Tao, Feng Xiaojie, Qin Bing, Ceng Chenhao

RADIATION PROTECTION. 2016, 36(5):  279-284. 

Abstract ( 28 )   PDF (2293KB) ( 42 )  

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Based on the CFD theory, a discrete phase model (DPM) was developed using FLUENT for digital simulation. By comparing different explosive load factor β and ventilation system, the motion law and concentration of PM₁₀ particles were analyzed. Finally, this paper studied the effect of ventilation system on particle dispersion and provided a theoretical reference to the radiological protection and emergency response to dirty bomb incidence.

Analysis of the calculation method of Micro Shield for many radioactive sources

Wang Qiyun, Yang Bin

RADIATION PROTECTION. 2016, 36(5):  285-290. 

Abstract ( 28 )   PDF (1453KB) ( 65 )  

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Micro Shield is often used for the shielding calculation of complex space geometry structure.Taking a wastewater discharge monitoring room of SRTF laundry as an example, this paper attempts to simplify the modeling process, and compares the modeling results with the MCNP to find an appropriate way enhancing the credibility of Micro Shield calculation.

Measurements of equilibrium factor of radon and its progenies in some fields

Wu Hao, Xiao Detao, Li Zhiqiang, Xiao Yongjun, Xiao Gaoping, Li Yue

RADIATION PROTECTION. 2016, 36(5):  291-296. 

Abstract ( 29 )   PDF (1280KB) ( 44 )  

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Dose caused by environmental radon progeny is approximately estimated mainly by using the environmental radon exposure and the recommended equilibrium factor of radon and radon progeny. However, environmental conditions vary greatly in different places, and therefore the equilibrium factor of radon and radon progeny also vary greatly, and the estimation method results in a big estimation error. To improve the quality of the dose caused by radon progeny estimated based on radon exposure, it is necessary to measure the equilibrium of radon and radon progeny in typical places. By adopting the NRL-Ⅱcontinuous radon monitor and NR-200A continuous radon daughters monitor developed by the University of South China, the equilibrium factors of radon and its daughters in the air are measured in fields including Qinshan Nuclear Power Base, Hunan Xiangya Hospital, Hunan Provincial Tumor Hospital and Jinyuan Uranium Industry Company. The results show that the equilibrium factors of Radon and its Progenies in coastal areas and Radiation Therapy Center was 40% less than the recommended value. The regional equilibrium factors of Radon and its Progenies in some fields with good ventilation and air purification measures are even smaller, and the equilibrium factors of radon and its Progenies in the indoor environment of inland provinces are similar with the recommended value.

Features of RODOS/JRODOS and their application in nuclear emergency management of Germany

Gao Weihua, Yao Rentai

RADIATION PROTECTION. 2016, 36(5):  297-306. 

Abstract ( 54 )   PDF (1910KB) ( 57 )  

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Through long-term development, RODOS system has been one of emergency response resources of nuclear accident for many counties and represents the technology level of development in this field. There is much reference worth for the emergency management in China through understanding the development and application of RODOS. This paper describes the general situation of development of RODOS, especially for the physical model and function of RODOS and the structure and feature of JRODOS. In addition, the emergency response mechanism of nuclear accident and application of RODOS/JRODOS in Germany are also introduced.

The effects of microorganisms on HLW-geodisposal scenarios

Liu Hongyan, Yang Zhongtian, Zuo Yahui

RADIATION PROTECTION. 2016, 36(5):  307-316. 

Abstract ( 26 )   PDF (2211KB) ( 30 )  

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This paper summarized the research progress on the risk of the microorganisms in high-level radioactive waste geological disposal, and provided a proposal for China’, HLW-geodisposal microbe research in the future.

Research on shielding performance measurements of a spent fuel transportation container

Sun Hongchao, Li Guoqiang, Zhuang Dajie, Wang Renze, Sun Shutang, Meng Dongyuan, Wang Xuexin, Zhang Jiangang, Cao Fangfang, Zhang Hongjian

RADIATION PROTECTION. 2016, 36(5):  317-321. 

Abstract ( 38 )   PDF (1874KB) ( 57 )  

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The radiation shielding performance measurements of transport container is the important content to ensure transportation safety of radioactive material. The radiation shielding performance of radioactive material package must meet the requirements of “Regulations for the safe transport of radioactive material” (GB 11806—2004). However, some of the problems and difficulties reflected in practice need to be solved, such as the measurement results of neutron radiation level of container outer are not always reliable. In this paper,the monitoring results of using both the neutron multi-sphere spectrometer and portable neutron measurement instrument are compared, and the MCNP runs are done to study the shielding performance measurements of spent fuel package. The results of monitoring and simulation are compared, some factors are discussed, and an optimized scheme is recommended.

The reforming scheme of heavy water leakage into the secondary coolant detection system of Es-Salam Reactor

Wang Yong, Yang Jiayin

RADIATION PROTECTION. 2016, 36(5):  322-325. 

Abstract ( 30 )   PDF (1407KB) ( 30 )  

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Problems exist in the current Es-Salam Reactor's detection system for heavy water leakage into the secondary coolant that include slow response time and the incapacity of producing the leakage quantity of heavy water. A reforming scheme is proposed to solve the above problems. For ¹⁶N monitoring system detector efficiency was simulated with MCNP code. The reforming scheme improves the response speed and can effectively determine the amount of heavy water leakage to enhance the safety of reactor.

Standardization status and suggestions for decommissioning of nuclear facilities in China

Liu Lipo, Li Guoqing, Jin Liqiang, Luo Feng

RADIATION PROTECTION. 2016, 36(5):  326-334. 

Abstract ( 51 )   PDF (1444KB) ( 107 )  

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This paper reviewed the current standardization status of nuclear facility decommission, identified problems exist, and then put forward suggestions for the plan and system, the management standards, the technology standards, and the implementation and supervision of standards as well.