Table of Content

20 September 2025 Volume 45 Issue 5

  

Research progress and prospects of direct semiconductor neutron detectors

WANG Linjing, WANG Chuan, LI Hua, LI Deyuan, CHEN Faguo, LIU Liye, ZHANG Pengpeng

RADIATION PROTECTION. 2025, 45(5):  445-458. 

Abstract ( 7 )   PDF (11064KB) ( 4 )  

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Direct semiconductor neutron detectors have significant advantages such as small volume, theoretical detection efficiency of 100%, and simple device structure, making them a key direction for the future development of semiconductor neutron detectors. Currently, novel materials with distinct neutron response capabilities suitable for fabricating direct-type semiconductor neutron detectors include h-BN, LiInSe₂ and LiInP₂Se₆. This paper provides a detailed review of the latest advancements in research on direct semiconductor neutron detectors based on h-BN, LiInSe₂ and LiInP₂Se₆. The review includes the following aspects: crystal growth, characterization and optimization of growth processes; electrical properties of crystals and carrier transport capability; detector structure design and neutron detection performance testing. This paper also summarizes the current research status and development trends, and offers an outlook on the future of direct semiconductor neutron detectors.

Analysis of diagnosed cases of occupational radiation sickness in some provinces and cities of China

YU Chengcheng, YU Zhiping, XING Zhiwei, ZHAO Fengling

RADIATION PROTECTION. 2025, 45(5):  459-465. 

Abstract ( 4 )   PDF (963KB) ( 1 )  

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Through case analysis on occupational radiation-induced diseases diagnosed in recent years in some provinces and cities in China, this study identifies issues in the diagnosis of occupational radiation-induced diseases and explores solutions. A total of 45 cases were collected from Sichuan, Jiangsu, Inner Mongolia, Shandong, Henan, Tianjin, Anhui, Zhejiang, and the nuclear industry system (8 provinces and 1 system). Additionally, 29 cases were collected from other provinces or provinces that did not report to the system, resulting in a total of 74 cases. The medical records were aggregated and analyzed. A questionnaire survey was conducted among 140 diagnostic physicians from 8 provinces and 1 secction to assess their awareness of standards, participation in standard dissemination, and application of standards. From 2013 to 2020, a total of 74 individuals were diagnosed with occupational radiation-induced diseases, involving 83 cases. Among these, 35 individuals (42 cases) were diagnosed with harmful tissue reactions (deterministic effects), with the top three diseases being radiation-induced cataracts, radiation-induced skin injuries, and chronic radiation sickness. Additionally, 39 individuals (41 cases) were diagnosed with radiation-induced tumors, with the top three being radiation-induced thyroid cancer, radiation-induced leukemia, and radiation-induced lung cancer. Eight individuals were diagnosed with two or more types of occupational radiation-induced diseases. The awareness rate of diagnostic standards among physicians was 76.2%, and 77% of physicians participated in standard dissemination activities. Regarding standard application, 51.2% of physicians reported not using the standards or using them fewer than two times per year. The analysis reveals that in the diagnosis of occupational radiation-induced diseases, there are issues such as overestimation of radiation doses and low awareness and usage rates of diagnostic standards. Understanding the current status of occupational radiation-induced diseases is essential to address these challenges.

The introduction of NCRP wound model and the retention fractions and excretion fractions for wound intake of ²⁴¹Am using the wound model

CHEN Qianlan, PANG Hongchao, LUO Zhiping, LIU Senlin

RADIATION PROTECTION. 2025, 45(5):  466-473. 

Abstract ( 5 )   PDF (4160KB) ( 0 )  

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This research introduces the background, model’s structure and parameters of the National Council on Radiation Protection and Measurements’ (NCRP) No.156 Report’s Wound Model. By connecting the NCRP Wound Model with the current newest System Model(ICRP No.141 Publication) and Human Alimentary Tract Model (ICRP No.100 Publication), the retention and excretion fractions for wound intake are calculated. After testing the correctness of the program of this research of the Wound model with data in reference, the Wound model is connected with the already correct System Model and HATM. Then the retention fractions changing with time in Wound site, Lymph nodes, Liver, Skeleton, daily urine and faeces excretion fractions after wound intakes of different kinds ²⁴¹Am are calculated, which gives support for the intake evaluation for accidental wound intake of ²⁴¹Am .

Design and detection efficiency analysis on online γ radiation monitoring device for AP1000 steam generator blowdown pipeline

WANG Yilin, QIAO Youlong, YU Xiaodong, LIU Weili, XIA Sanqiang, SU Changyuan

RADIATION PROTECTION. 2025, 45(5):  474-481. 

Abstract ( 7 )   PDF (9082KB) ( 1 )  

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In order to ensure that radioactive substances in the external steam supply of AP1000 unit meet the relevant standard requirements, real-time online monitoring of the γ radioactivity in the steam generator blowdown pipeline is carried out. The online γ radiation monitoring device consists of four NaI (Tl) γ spectrometers, an on-site radiation processing unit, and a lead shielding bracket. The simulation results indicate that the detection efficiency of the monitoring device is less affected by the energy of γ rays. By preparing pipelines with different activity concentrations of ¹³⁷Cs and calibrating the monitoring device, a detection efficiency of 7.96×10^-2 was obtained. At a 95% confidence level and a measurement time of 15 seconds, the minimum detectable activity concentration was 2.53×10⁴ Bq/m³. The precision of the monitoring device was 2.86%, and the accuracy was better than ±9%, meeting the measurement requirements.

Application of enriched boric acid in the primary system of a PWR unit and the preliminary study regarding its impact on the material corrosion and radiation source term control

WANG Zhu, YANG Zhichao, CHU Jianwei, SU Xing, ZHOU Jia, CHEN Weizhong, MA Qiang, WANG Suyuan

RADIATION PROTECTION. 2025, 45(5):  482-488. 

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This paper introduced the first application of enriched boric acid in a third generation PWR unit, and the water chemistry control strategy with higher and constant pH_t value (7.20) of the reactor coolant from the beginning of the cycle is realized through its application, which plays an important role in reducing primary material corrosion and radiation source term control. Field application practice shows that through the implementation of the above mentioned water chemical control strategy, the corrosion rate and release of primary metal materials, especially nickel in the steam generator tubes is reduced to a lower level, which is a benefit to ensuring the integrity of the second barrier and controlling of activated corrosion products and finally achieving the goal of minimizing the exposure dose to personnel.

Determination of ⁶³Ni in soil samples by liquid scintillation counting after the separation of anion resin and Ni resin

YANG Hailan , BAO Li, LIU Wangdong, GUO Chen, REN Zhemin, YANG Youkun, YIN Yali, GOU Rongxia

RADIATION PROTECTION. 2025, 45(5):  489-495. 

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An analysis method for the determination of ⁶³Ni in soil samples using anion resin and Ni resin and liquid scintillation counter was developed. Through pretreatment processes such as grinding, leaching, and precipitation, interfering radionuclides are separated by using resin. The chemical recovery is determined by an atomic absorption spectrometer, and then the activity concentration of ⁶³Ni is measured by the liquid scintillation counter. The experimental results show that the chemical recovery of this method reaches 76.1%±3.8%, the detection limit is (26.0±1.2) Bq/kg, and the decontamination factors for common interfering radionuclides such as Fe, Co, Cs, and Zn reach 10² to 10⁵. Among them, this method innovatively optimizes the resin separation process and chemical treatment conditions. It is simple and reliable to operate, with a stable recovery rate. The method can be used for determination of ⁶³Ni in environmental soil samples arround nuclear facilities.

Direct measurement of gross α/β in wastewater by liquid scintillation method

WANG Ruijun, BAO Li , CHEN Ling, REN Xiaona, LIU Wangdong, SHI Qiqi, CUI Linhong

RADIATION PROTECTION. 2025, 45(5):  496-502. 

Abstract ( 7 )   PDF (4796KB) ( 1 )  

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When gross α/β in wastewater is high, liquid scintillation spectrometer with α/β discrimination function can be used to directly determine gross α/β, which has the outstanding advantages of simple process, low background and high counting efficiency, and the result can be analyze by considering the liquid scintillation count spectrum. In this paper, the concentration of gross α/β activity in wastewater was directly determined by LSC, and the results were compared and analyzed. The main contributing nuclide of gross β in this batch of wastewater samples is ⁹⁰Sr, and the activity concentration of gross β is three orders of magnitude higher than that of gross α. The relative deviations of gross α and gross β measured by liquid scintillation method and gas-flow proportional counting method are 2.2%-22.5% and 2.3%-16.7%, respectively, and the correlation is good.

Validation research of the splitting puff (SPUFF) model based on wind tunnel experiment at Sanmen nuclear power plant

TAO Hengrui, YANG Li, WANG Cunyou, LI Huanting, ZHANG Xiaohui, FANG Sheng, LI Xinpeng, CHEN Yixue

RADIATION PROTECTION. 2025, 45(5):  503-516. 

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The performance of atmospheric dispersion models varies across different scenarios, making it crucial to validate these models in multiple scenarios to quantify their range of performance. This paper integrates the California Meteorological Model (CALMET) with the Lagrangian splitting puff model (SPUFF) to perform the local-scale dispersion simulation based on the multiple wind tunnel experiments under neutral atmospheric condition at the Sanmen nuclear power plant (NPP) scenario conducted in the multi-complex terrains. The simulations are compared in detail with the measurements from networked sites and individual axial sites at ground level, aiming to further evaluate the performance of SPUFF against multiple dispersion scenarios, both qualitatively and quantitatively. The evaluation results reveal that SPUFF demonstrates sufficient dispersion across multiple scenarios, which effectively covers most of the measurement sites. Meanwhile, the numerical evolution of the plume closely matches the trends observed in the measurements, accurately reproducing the values at the axial sites. The statistical results indicate that the performance of SPUFF is excellent. All four statistical metrics, including the fraction of simulations within a factor of two of the measurements (FAC2), the fractional mean bias (FB), the normalized mean-square error (NMSE), and the normalized absolute difference (NAD) meet model acceptance criteria at both networked sites and individual axial sites. Among them, FAC2 in all scenarios reaches a good level of 0.51 and 0.83 for networked sites and individual axial sites, respectively; while FB achieves excellent performance at -0.03 and -0.06, respectively. The above results demonstrate that SPUFF is suitable for various dispersion scenarios under neutral atmospheric condition in complex NPP sites with multiple terrains, making it an important tool for future early response to nuclear emergency.

Research and development of a dynamic optimization decision model for nuclear emergency evacuation based on deep reinforced learning

LI Mingye, YAO Rentai, GUO Huan, ZHANG Junfang, LV Minghua, XU Xiangjun, NIU Yanjing, JIA Bohui

RADIATION PROTECTION. 2025, 45(5):  517-529. 

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Timely and effective evacuation of people during nuclear accident scenarios is critical to minimize radiation exposure and ensure public safety. Although traditional path planning algorithms can quickly compute static shortest paths, they are difficult to adapt to the challenges posed by dynamic changes in radiation fields. In this paper, a dynamic optimization decision model (MD-DQN algorithm model) for nuclear emergency evacuation based on deep reinforced learning is proposed. By establishing a Markov decision process (MDP) model, and taking the dynamic radiation field information, road network information, and real-time location as the state space, a multifactorial reward function that comprehensively considers the path length, radiation exposure and directional guidance is designed. The inteligent agent is driven to learn the optimal dynamic evacuation decision-making strategy autonomously. Meanwhile, the convergence and generalization performance of the algorithm are improved by optimizing the network structure design and instant reward mechanism. Simulation experiments show that compared with the traditional Dijkstra’s algorithm and A^* algorithm, the MD-DQN algorithm is able to effectively avoid high-risk areas in time, significantly reduce the radiation dose exposure of personnel in the evacuation process, and has better real-time path adjustment ability and environmental adaptability. The research results can provide an efficient, intelligent and decision support tool for practical nuclear emergency evacuation decision-making, and provide new research ideas for the future in the field of intelligent decision-making driven by multi-source radiation, multi-intelligent agent and real-time data.

Clearance practice of radioactive activated carbon generated by nuclear power plants

LI Ke, LIU Dan, HUANG Houshun, HAN Xu, GUO Xiliang, GAO Chao, YAN Xiaojun

RADIATION PROTECTION. 2025, 45(5):  530-539. 

Abstract ( 7 )   PDF (2241KB) ( 0 )  

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Based on recent practical experience in the clearance control of slightly contaminated materials in China and in accordance with current national laws, regulations, standards, and relevant requirements, a clearance assessment was conducted for 102 temporarily stored barrels of waste activated carbon. Through source term analysis, radiation level measurement, sampling representativeness evaluation, and clearance assessment, the annual effective doses to workers and residents resulting from the incineration of the cleared waste activated carbon were estimated.Analysis results indicate that, under the premise of ensuring sampling representativeness, the optimal measurement time for radioactive waste activated carbon is 30,000 s, and the optimal sampling ratio is 50%. The activity concentration of radionuclides in the waste activated carbon samples complies with the deah release criteria outhined in GB 27742—2011.The annual effective doses to workers and surrounding residents during the incineration process of the cleared activated carbon meet the dose criteria for reuse processes.