Table of Content

20 March 2022 Volume 42 Issue 2

  

Progress of absorption method in pulsed X-ray spectra measurement generated by ultra-short ultra-intense laser-solid interaction

SONG Honghu, YI Hongchang, WEI Shuoyang, WU Zhen, ZHANG Hui, LI Junli, QIU Rui

RADIATION PROTECTION. 2022, 42(2):  89-101. 

Abstract ( 157 )   PDF (6161KB) ( 135 )  

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The measurement of pulsed X-ray energy spectrum in ultra-short and ultra-intense laser facility is of great significance and reference value in the field of diagnosis and radiation protection. Presently many countries have established ultra-short and ultra-intense laser facility research platforms, and plenty of research have been conducted in this area. This paper introduces Ross Pair and differential absorption methods, which are commonly used in low and medium energy spectrum measurement for pulsed X-ray produced by laser-solid interaction. This paper also reviews the research progress and applicability of these two methods in recent years from the aspects of detector structure, filter material selection, detection medium selection, scattering control, and unfolding methods, with the aim to provide a reference for domestically related research and application. The detector structure based on absorption method mainly includes stack and array designs: stack design is more suitable for the angular distribution measurement of energy spectrum, while to some extent array design could control X-ray scattering and give evaluations of detector crosstalk. The filter material selection, scattering control and unfolding method are optimized based on the spectrometer designed in San Diego Laboratory. In addition, the detector media is mainly a passive imaging plate or thermoluminescence detector. Due to the inconvenience of off-line operation, researchers are committed to using active detectors, such as scintillators and semiconductor detectors, to achieve active measurement of pulsed X-ray energy spectrum.

Research progress of EC-SOD radiation resistance

ZHU Mengmei, OUYANG Tao, HUA Tianzhen, LI Kun, YU Bing

RADIATION PROTECTION. 2022, 42(2):  102-110. 

Abstract ( 162 )   PDF (2331KB) ( 113 )  

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The tissue and organ damage process caused by electromagnetic radiation, ionizing radiation, optical radiation, and other radiation is often accompanied by reactive oxygen species (ROS) activation and DNA damage. Superoxide dismutase (SOD) is an antioxidant metalloenzyme that exists in the organism, which plays a vital role in the body’s oxidant/antioxidant balance, and participates in the occurrence and development of many diseases. Extra-cellular superoxide dismutase (EC-SOD) is mainly found in the extra-cellular matrix. Many studies have demonstrated that EC-SOD plays a protective role in radiation damage to a variety of tissues and organs, which mainly prevents further damage to cells and tissues by reducing ROS levels, anti-angiogenesis, anti-chemotactic and anti-inflammatory. Therefore, we have reviewed the protective role and mechanism of EC-SOD and its mimetics or analogues in radiation protection, and provide a theoretical reference for the application of EC-SOD with radiation resistance.

Research progress of reactive oxygen species and radiation-induced skin injury

CAI Weichao, CAO Weihong

RADIATION PROTECTION. 2022, 42(2):  111-118. 

Abstract ( 129 )   PDF (953KB) ( 64 )  

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When the skin is irradiated by radioactive sources, the decomposition of water is the first process to produce reactive oxygen species (ROS), and then the respiratory chain and inflammatory process also produce a large number of ROS. As a signal molecule, ROS plays an irreplaceable role in regulating physiological and biochemical processes. In this paper, the changes of ROS by radiation-induced skin injury, the mechanism of ROS intervention and the regulation of ROS elimination were reviewed in order to link the metabolism of ROS with the physiological and pathological reaction of radiation injury, so as to provide reference for related research and clinical treatment.

Determination of uranium isotopes in aerosol samples using UTEVA resin and alpha spectrometer

LI Zhou, LI Pengxiang, YANG Hailan, MA Xuyuan, LIN Haipeng, GAO Zequan, HAN Yuhu, REN Xiaona

RADIATION PROTECTION. 2022, 42(2):  119-123. 

Abstract ( 109 )   PDF (1149KB) ( 79 )  

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An analysis procedure for the determination of uranium isotopes in aerosol samples using UTEVA resin and alpha spectrometer in hydrochloric acid system was developed. Uranium was totally transferred to the solution by using mixed acids and H₂O₂ after fusing at 600 ℃ for 4 hours. Ascorbic acid was added to convert the sample solution to reduction system, and then uranium was purified by UTEVA resin column, followed by source electroplating and measurement with an alpha spectrometer. Spiked samples and real aerosol samples were analyzed to validate the procedure. All the measured results agreed very well with the target values. The chemical recoveries were stable and higher than 95% with coefficient variation of ±5%.

Research on radiation environment monitoring level of urban radioactive waste repository in Jiangsu province

TAN Weiyang, ZHU Xiaoxiang, WANG Peng, ZHANG Yongtao, LIU Ying, GONG Chunhui, YANG Yi

RADIATION PROTECTION. 2022, 42(2):  124-130. 

Abstract ( 176 )   PDF (3963KB) ( 125 )  

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With the widespread application of nuclear technology in various fields, radiation environment safety has received more and more attention. This article takes the urban radioactive waste storage in Jiangsu Province as the research object,. The radiation environment arround the radioactive waste storage has been continuously monitored for 6 years since 2015. The gamma radiation dose rate in the air around the radioactive waste storage, the gross alpha and gross beta in the water resources and the radionuclides in the soil have been monitored, and the radiation monitoring results are analyzed and evaluated. The results show that the mean range of the gamma radiation dose rate in the air at sensitive points is 59.0-96.5 nGy/h, the mean range around source storage is 81.92-103.32 nGy/h; the mean range of the gross alpha and gross beta in water resources are 0.90×10^-2-5.87×10^-2 Bq/L and 3.00×10^-2-16.00×10^-2 Bq/L, respectively. The changes in the gamma radiation dose rate in the air are mainly related to the distance from the source storage and the management of waste sources; the changes in the level of radioactivity in water are mainly related to the annual precipitation; the changes of radionuclides in the soil are mainly related to radioactive aerosols. All changes fluctuate within the background range, with almost no impact on the environment, which can ensure the the radiation environment safety.

The influence of emergency exhaust pipe on the velocity and gas mixing in main chimney

ZHENG Jinge, CHENG Weiya, LIU Weifu, HAO Guizhen, WANG Chenxiao, GUO Haocheng, ZHAO Yulun, CHEN Ling

RADIATION PROTECTION. 2022, 42(2):  131-140. 

Abstract ( 97 )   PDF (8815KB) ( 21 )  

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The computational fluid dynamics (CFD) method is used to simulate the influence of the emergency exhaust pipe on the gas component mixing inside the main chimney. The coefficient of variation (COV) of velocity and tracer gas concentration are used to represent the mixing uniformity on each surface. Three typical working conditions were compared and studied, namely high wind speed (about 13.1 m/s), medium wind speed (about 8.2 m/s) and low wind speed (about 0.56 m/s). The results show that when the wind speed is 13.1 m/s and there is no internal pipe, the distribution of velocity and gas concentration is more uniform, and the COV values on each surface are reduced by 2.8% and 2.0% respectively; When the wind speed is 8.2 m/s and there is no internal pipe, it is conducive to the uniform distribution of velocity (COV value decreases by 1.5%), but reduces the mixing uniformity of gas components (COV value increases by 3.1%); When the wind speed is 0.56 m/s and there is no emergency exhaust pipe, the velocity and gas components show better mixing uniformity, and the COV values are reduced by 4.8% and 0.02% respectively. Comparing the simulation results with experimental data, more than 92.5% of the simulation data has a deviation of less than 15% from the experimental values.

Validation of dose assessment model for atmospheric tritium release

YANG Jie, LIAN Bing, LV Caixia, WANG Yan, CHEN Jia, CHEN Jiachen, YUE Qi

RADIATION PROTECTION. 2022, 42(2):  141-145. 

Abstract ( 136 )   PDF (901KB) ( 105 )  

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Based on the 2014-2016 emission data of tritium from Qinshan Nuclear Power Plant (QNPP) , the specific activity model recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was used to evaluate the tritium-induced radiation dose to the public who resides near Qinshan Nuclear Power Base. The results were compared with the tritium monitoring data around Qinshan Nuclear Power Base during the same time period. The evaluated results based on tritium effluent emissions were similar to those based on environmental monitoring data and were at the same level. It is recommended that the specific activity model should be used to evaluate the public radiation dose caused by airborne tritium.

Study on spontaneous diffusion of CaCl₂ solution in GMZ Na-bentonite

YANG Ting, YANG Chengyan, ZHENG Jugong, ZHA Wenhua, LIANG Haian, FENG Yanyan

RADIATION PROTECTION. 2022, 42(2):  146-154. 

Abstract ( 125 )   PDF (4640KB) ( 118 )  

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The groundwater at the near site of the geological disposal repository of high-level radioactive waste may affect the barrier system in the disposal repository and may reduce the safety and stability of the disposal repository. In order to study the diffusion law of salt ions in the groundwater into the buffer backfill system in the disposal repository, the spontaneous imbibition, adsorption and diffusion of Gaomiaozi (GMZ) bentonite from Inner Mongolia in Ca²⁺ solution was carried out in laboratory under static non-external loading condition. The spontaneous diffusion of Ca²⁺ in bentonite samples with different dry densities and initial saturation was analyzed based on soil microstructure and classical diffusion theory. The results showed that under the condition of the same initial saturation of bentonite, the retardation coefficient increases with the increase of dry density, while the diffusion capacity of Ca²⁺ decreases. When the dry density of bentonite was the same, the retardation coefficient and diffusion capacity of Ca²⁺ decrease with the increase of initial saturation.

Preliminary study on formula of radioactive waste resin solidified by epoxy resin

SUN Maosheng, ZHANG Rui, YAN Cangsheng

RADIATION PROTECTION. 2022, 42(2):  155-160. 

Abstract ( 131 )   PDF (3192KB) ( 72 )  

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In order to solidify medium and low radioactive waste resins into a stable solid form to meet the disposal conditions, the solidification formula was studied by using epoxy resin as substrates with addition of appropriate curing agent, diluents and flame retardant. Experimental results show that when the formula is E-44 epoxy resin∶651 curing agent∶diluents=1∶0.53∶0.05 (38∶20∶2), and the quality tolerance is 50%, then the solidified body has the best performance, which meets the requirements of GB 14569.2. The results prove that solidifying radioactive waste resin with epoxy resin is feasible.

Application of emergency evacuation simulation in the optimization of road evacuation scheme for nuclear power plant

DONG Li, WANG Mengxi, LIU Xinjian, LIU Senlin

RADIATION PROTECTION. 2022, 42(2):  161-176. 

Abstract ( 110 )   PDF (8596KB) ( 34 )  

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The emergency road of nuclear power plant has always been the focus of the site emergency evacuation feasibility analysis. The probabilistic risk assessment method is applied to the emergency evacuation simulation of nuclear power plants in this paper. Using self-designed simplified evacuation simulation program, combined with the site characteristics of accident source term, population, road and meteorological conditions, the possible exposure doses to the public and staff under emergency conditions of multiple nuclear power plant sites are calculated, and the risks of each site are compared. Besides, combined with the practical problems encountered in the emergency evacuation road scheme of Xiapu site, while ensuring the effective evacuation of the public and staff under emergency conditions, the schemes of emergency evacuation road are compared and selected in combination with the actual situation of the plant site, which could provide reference for the implementation of the Xiapu project. The program and the method mentioned above can also provide technical support for the subsequent development of island nuclear power plant and small heating reactor, which is also conducive to more intuitive public communication of nuclear power.