Table of Content

20 July 2025 Volume 45 Issue 4

  

Some concepts, standards and their evolution related to the regulatory scope of radiation protection

XIA Yihua, SONG Weijie, NIE Peng, YUAN Yang, XU Yao

RADIATION PROTECTION. 2025, 45(4):  313-319. 

Abstract ( 31 )   PDF (2312KB) ( 18 )  

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This article sort outs the three basic concepts related to the regulatory scope of radiation protection. The principles for delineating regulatory scope and some difficult issues were analyzied. The evolution of domestic and international standards as well as potential differences between them was also discussed. Preliminary suggestion on their applicability in the revision of China's relevant standards in the next step was put forward.

Development of detailed human eye model and dose conversion coefficients for monoenergetic photon

WEI Xiaofeng, WANG Chuan, LIU Liye, LI Xiaodun, CAO Qinjian, ZHAO Yuan, JIAO Yan

RADIATION PROTECTION. 2025, 45(4):  320-326. 

Abstract ( 23 )   PDF (5861KB) ( 15 )  

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Based on medical anatomy, radiation dosimetry and characteristic physical parameters of Chinese adults, a detailed model for equivalent dose of the eye lens was established. The model consists of two parts: binocular eyeball and head phantom; The model consists of two parts: binocular eyeball and head; the eyeball possesses a detailed anatomical structure consisting of 8 tissues, and the head is composed of soft tissue and hard bone; The left and right eyeballs are symmetrically placed inside the head model. By employing this model, the equivalent dose of the eye lens and the conversion coefficient H_lens/K_a were computed when the 0.01-10 MeV monoenergetic parallel photon beam was irradiated at 0°, 90°, and 180°. The results showed that the H_lens/K_a of photons which energy is less 40 keV at 0° and 90° incidence reported by ICRP 74 was 1.04-4.78 times higher than that of the proposed paper, mainly due to the increase of cornea and anterior chamber in the proposed model. H_lens/K_a of ICRP 110 reported was 0.43, 0.93 and 1.45-1.65 times higher than that in this paper of 10 keV, 20 keV and 3-10 MeV irradiated at 0°, and the model in this paper improved the underestimation and overestimation of the dose caused by the excessive thickness of the anterior tissue of the ocular lens in the ICRP 110 report. The H_lens/K_a of the Behrens model when irradiated with 30-60 keV and 100 keV-10 MeV photons at 180° was 4.05-1.18 and 0.86-0.92 times of that in this paper, the difference was that the head phantom was determined to be an elliptical cylinder with a skull reference to the human body size of Chinese adults. And the ratio of the binocular eye lenses was 130%-710% when irradiated at 90° by 20 keV-1 MeV photons, this indicates that special attention should be paid to the radiation risk caused by the non-uniform irradiation.

Research on NaI(Tl) gamma spectrum radionuclide identification technology based on hybrid PCA-FCN model

LIU Xin, ZHAO Ri, TAN Jun, WANG Maolin, HUANG Jian, ZHANG Jing, LIANG Runcheng, LIU Zhaoxing, SHI Zhongyan, WANG Jia, LINGHU Renjing, LIU Liye

RADIATION PROTECTION. 2025, 45(4):  327-336. 

Abstract ( 20 )   PDF (9556KB) ( 11 )  

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The poor energy resolution of NaI(Tl) detector makes it difficult to accurately identify radionuclides based on the acquired gamma spectrum. In order to improve the identification accuracy, this paper proposed a hybrid PCA-FCN identification model based on the advantages and disadvantages of existing research methods and models. Based on the randomization strategy, a robust gamma energy spectrum datasets was constructed through empirical measurements and Monte Carlo simulations. The datasets was utilized to train the model and conduct validation experiments. Results indicate that the PCA-FCN model achieved radionuclide identification performance factors of 0.982 3 for average precision (A_P) and 0.980 1 for the F₁ score, markedly surpassing the performance of PCA models, FCN models, and traditional full-energy peak analysis methods. The identification accuracy can still be maintained under varying spectral complexities and statistical fluctuations. This conclusion shows the potential of the PCA-FCN model and the random sample generation strategy for future applications in quantitative measurement of radioactivity.

Development of a dual-channel high sensitive on-line monitor for radioactive aerosol

SHANG Jie, MAO Xueyong, YANG Yi, ZHANG Yanting, ZHANG Fuguo, YANG Liu

RADIATION PROTECTION. 2025, 45(4):  337-342. 

Abstract ( 21 )   PDF (4237KB) ( 8 )  

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To address the demand for rapid warning capability and laboratory-comparable sensitivity in radioactive aerosol monitoring at nuclear facilities, a high sensitive online radioactive aerosol monitor has been developed. The instrument features a dual-channel (real-time/delayed) detection structure, achieving performance enhancements through:(1)Extended sampling track length;(2)Optimized real-time channel response (1 min data refresh);(3)Integrated radon interference suppression combining decay correction, energy spectrum discrimination, and α/β ratio compensation techniques. This single device simultaneously achieves both rapid response (1 minute response time for real-time channel) and high sensitivity (detection limits of 10^-4 Bq/m³(α) and 10^-2 Bq/m³ (β) in delayed channel), resolving the contradiction between these two parameters in aerosol monitoring. Compared with conventional online aerosol monitors, the α and β detection limits have been improved by two orders of magnitude, while also reducing both the workload of laboratory analysis for offline sampling and radiation exposure risks.

Rapid determination of uranium concentration in in-situ leaching uranium stock solution with CO₂ and O₂

DONG Shuang, LIU Jinming, SONG Jing, SUN Liping

RADIATION PROTECTION. 2025, 45(4):  343-348. 

Abstract ( 19 )   PDF (2594KB) ( 19 )  

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To establish a safe and rapid uranium concentration analysis method for CO₂ and O₂ in-situ leaching uranium technology. Research has shown that in an anhydrous ethanol water medium, UO₂²⁺forms a red complex with 5-Br-PADAP and F^- under the mixed chelating agent CyDTA sulfosalicylic acid sodium fluoride. The optimal wavelength for measuring absorbance is 580 nm, and the suitable pH range for color development is 6.68-9.24. The amount of anhydrous ethanol used is 7.5 mL. The analysis results showed that the RSD was less than 1.0%. This method has shown good application in measuring uranium concentration in CO₂ and O₂ leaching solutions of uranium mining and metallurgy. The use of anhydrous ethanol instead of acetone has improved the efficiency and operational safety of uranium concentration analysis methods.

Radiation environment monitoring and analysis of a rare earth tailing pond in Baotou

WU Dong

RADIATION PROTECTION. 2025, 45(4):  349-354. 

Abstract ( 27 )   PDF (1911KB) ( 21 )  

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The radiation environment level of a typical rare earth tailing pond in Baotou City is monitored and analyzed. The results show that the average γ-radiation dose rate of the slag in the tailings dam is 680.3 nGy/h, which is about 6.6 times of the average background γ-radiation dose rate in Baotou city. The Th-232 activity concentration in soil samples was from 36.1 to 364.7 Bq/kg during the three monitoring years, which was within the normal fluctuation range compared with the national monitoring range in 2019. The average activity concentration of Th-232 in the tailing pond was 1.417 Bq/g. The tailing reservoir should be strictly supervised to avoid the spread of radioactive contamination. The circulating water of tailing pond workshop formed by tailing pond seepage contains a very small amount of radioactive thorium, and its thorium nuclide concentration is similar to the local groundwater background level during the monitoring period.

Calculation of effective dose coefficients for intake of typical actindes via contaminated wound for reference adults

LEI Jieying, XU Ming, LI Yuxiang, LI Shilong, ZHANG Zheng, ZHAO Yuanzhong, ZHANG Yang

RADIATION PROTECTION. 2025, 45(4):  355-361. 

Abstract ( 17 )   PDF (3025KB) ( 13 )  

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To assess the internal radiation dose in adult reference individuals due to the intake of actinides through wounds, this study integrates the wound model from the NCRP 156 Peport, the systemic models from ICRP Publications 137 and 141, and the human alimentary tract model from ICRP Publication 100. Following the theoretical methods of ICRP Publication 103, the effective dose coefficients for typical actinides taken in through wounds, corresponding to different intake categories, were determined. These actinides include ²²⁸Th, ²³⁰Th, ²³²Th, ²³⁴U, ²³⁵U, ²³⁸U, ²³⁷Np, ²³⁸Pu, ²³⁹Pu, ²⁴⁰Pu, ²⁴¹Pu, ²⁴¹Am, ²⁴²Cm, ²⁴⁴Cm, and ²⁵²Cf. The results show that the new dose coefficients, influenced by the combined effects of the new biokinetic models, absorption fractions and dosimetric models, are approximately 23% to 73% lower than the old dose coefficients. This provides a basis for accurately assessing the internal radiation damage caused by the intake of actinides through wounds in domestic settings.

Study on the stabilizing effect on Uranium in alkaline zirconium residue with phosphorus containing materials

GAO Yang, SUN Juan, WU Xuyang, REN Lijiang, AN Yifu, ZHANG Haoyan

RADIATION PROTECTION. 2025, 45(4):  362-370. 

Abstract ( 16 )   PDF (6414KB) ( 7 )  

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Taking alkaline zirconium residue as the research object, different phosphorus containing materials were used to stabilize Uranium in alkaline zirconium residue, with the aim to analyze the stabilization effects and mechanisms. The result shows that among several phosphorus containing materials used in the experiment, Ca(H₂PO₄)₂, KH₂PO₄, CaHPO₄, and Ca₃(PO₄)₂ can all achieve stabilization effects, while Ca(H₂PO₄)₂ and KH₂PO₄ having the best stabilization effect on Uranium, with stabilization efficiency of 98.35% and 99.59%, respectively. K₂HPO₄ can promote Uranium activation leaching in alkaline zirconium residue, which is related to the generation of HCO₃^- in alkaline conditions. The stabilization principle of Ca(H₂PO₄)₂ and KH₂PO₄ is to promote the transition from carbonate bound state and organic bound state Uranium to residual state. The stabilization effect is greatly affected by the acidity and alkalinity of the environment, and acidic conditions are more conducive to its stabilization. The stabilizing effect of Ca(H₂PO₄)₂ and KH₂PO₄ on Uranium in alkaline zirconium residue is positively correlated with the dosage. The optimal dosage of Ca(H₂PO₄)₂ and KH₂PO₄ is 1.2%, After stabilization, the proportion of residual state Uranium is about 98.6%. HCO₃^- is the main factor affecting the long-term stability of Uranium. Within about 90 days, HCO₃^- can cause the stable Uranium in alkaline zirconium residue to leach out again. Ca(H₂PO₄)₂ and KH₂PO₄ can effectively inhibit the activation leaching of U in alkaline zircon residue by HCO₃^-, and the inhibitory effect of Ca(H₂PO₄)₂ is better than that of KH₂PO₄.

Research and practice of reducing radioactive waste resins in nuclear power plants

GE Jian'an, SHEN Xiaohui, SHEN Zhaogen, ZENG Jinzhong, LU Liyan

RADIATION PROTECTION. 2025, 45(4):  371-378. 

Abstract ( 20 )   PDF (4043KB) ( 7 )  

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Based on the characteristics of resin beds in various process systems of nuclear power plants, this article studies the effects of nuclear grade resin kinetic performance, oxidation stability, and exchange channels on the operational life of resin beds. It is concluded that the kinetic performance has a significant impact on the utilization rate of resin used to regulate the concentration of additives in process systems; The degradation of resin is manifested by the fracture of the skeleton and the detachment of exchange groups. The higher the crosslinking degree, the better the stability of the resin; The use of macroporous resin is beneficial for improving the purification factor of radioactive nuclei and the failure rate of the resin. Through the analysis of failure mechanisms and the summary of operational practices, the problems in the use of nuclear grade resins were explored and countermeasures were proposed.

Numerical analysis and structural design of dry acid gas absorber

ZHANG Xurui, ZHANG Yu, ZHANG Xiaobin, RUAN Jiasheng, XU Wei, ZHENG Bowen

RADIATION PROTECTION. 2025, 45(4):  379-387. 

Abstract ( 15 )   PDF (10212KB) ( 5 )  

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Compared with the conventional wet scrubber, dry acid gas absorber has simple operation process, low equipment cost and maintenance cost. In addition, waste liquid discharge can be avoided, which can effectively avoid secondary waste treatment problems. Through reasonable design equipment forms and structural sizes, the dry acid gas absorbers have high acid removal efficiency and absorbent utilization rate, and maintain a relative lower equipment resistance to reduce energy consumption. Therefore, the finite element analysis software workbench is used to simulate the equipment operation and analyze the influence of design parameters on the equipment performance. The results show that when the channel width increases, the utilization rate of absorbent can be effectively improved. However, the Sub-warehouse design of the absorbent silo can significantly reduce the equipment resistance while weakening the utilization rate of the absorbent. In addition, the design method of the shared runway can be further adopted, which can improve the gas distribution flow field of the equipment and ensure the effective use of the absorbent. Finally, through actual application and test, it is proved that the acid gas absorber can meet the needs of flue gas removal during continuous runtime.

Research on the effects of environmental atmosphere on graphite sphere frictional powder generation and the particle size and shape characteristics of graphite dust

GUO Lixiao, HUANG Shulong, ZHANG Yuhang, LIU Ying, CAO Jian, JIANG Ziqi

RADIATION PROTECTION. 2025, 45(4):  388-395. 

Abstract ( 18 )   PDF (11346KB) ( 7 )  

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In order to explore the frictional powder generation mechanism of graphite dust in high-temperature gas cooled reactors, reveal the influence of atmospheric environment on the characteristics of graphite dust generation, and to optimize the operational safety of high-temperature gas cooled reactors, the friction and wear behavior of graphite balls using the same process and material as those used in the HTR-PM commercial high-temperature gas cooled demonstration reactor was carried out under different atmospheric conditions, through self-designed friction and wear tests, and the physical properties such as particle size and shape of graphite dust were characterized. The results show that the friction mode in helium atmosphere is mainly abrasive wear, and graphite dust produces more particles in helium atmosphere, but the particle size distribution is relative small. The frictional powder production on the surface of graphite spheres is directly related to surface roughness, with an average maximum powder loss of about 160 mg per graphite sphere. The graphite dust particles generated by friction are flake like, with a median sphericity of 0.84 and a median aspect ratio of 0.61.

Dose evaluation of the rotation setup deviation in the single-isocenter volume modulated arc therapy for multiple brain metastases

HOU Lingtong, YAO Shengyu, FAN Shengyun

RADIATION PROTECTION. 2025, 45(4):  396-402. 

Abstract ( 22 )   PDF (5157KB) ( 16 )  

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The dose of the rotation setup deviation in single-isocenter VMAT for multiple brain lesions was evaluated by simulating rotations of known degrees (0.5°, 1°, 1.5°, and 2°) on the treatment planning system with varying tumor volume size (1 cm, 2 cm, and 3 cm) and distance to isocenter (up to 6 cm). A quantitative analysis of reducing the effect of the rotation setup deviation by increasing the tumor volume margin was done. With the increase of the rotation angle, the dose coverage of PTV decreased significantly, which was less for GTV. As the distance from the isocenter increased, the dose coverage rate decreased, and the smaller the target volume, the more significant it was. When the GTV was marginned by 2 mm, the decreasing trend of GTV dose coverage was significantly improved, all within -5%. It is recommended to use a six-dimensional couch top to correct the rotation setup deviation when using single-isocenter VMAT to treat patients with multiple brain metastases. For the organizations without a six-dimensional couch top, the appropriate margin should be considered according to the size of the target volume, the distance from the isocenter, and the clinical rotation setup deviation and tolerance.

Split-arc partial-field VMAT: A testicle-protective radiotherapy technique for penile cancer

WANG Yu, XU Deying, LIU Yunfeng, YU Liang

RADIATION PROTECTION. 2025, 45(4):  403-409. 

Abstract ( 20 )   PDF (5042KB) ( 0 )  

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To evaluate the difference in testicular dose between dual-arc conventional VMAT (dac-VMAT) and split-arc partial-field VMAT (sapf-VMAT) in postoperative radiotherapy for penile cancer, so as to provide a reference for preserving testicular function in clinical plan, ten patients aged 33 to 56 years with penile squamous cell carcinoma (PSCC) with lymph node metastasis were treated with the uRT-TPOIS plan system of United Imaging, and the range of jaw locking and arc of testicular avoidance were discussed. A paired t-test was employed and the dosimetry parameters of the plan target volume (PTV) and the radiation dose of organs at risk (OAR) were compared. All plans are normalized to a prescribed dose of 50.4 Gy covering 95% of the volume of PTV. The statistical results of machine unit (MU) in the dac-VMAT were 706.85±107.97, which were lower than those of 874.70±106.08 in the sapf-VMAT. The treatment time (T, s) of the dac-VMAT and sapf-VMAT was 174.44±13.61 and 183.89±14.33 respectively and the V1, V2, V3 of testes in the sapf-VMAT were 49.77±14.52, 5.42±5.60 and 0.40±0.69 respectively, all of which are significantly lower than 97.97±3.17, 83.15±19.14 and 7.35±4.81 in dac-VMAT; the P values were all less than 0.001. There were no significant differences in other outcomes. For patients of postoperative radiotherapy for penile cancer, compared with dac-VMAT, the testicular dose can be significantly reduced by sapf-VMAT, and the dose received is lower than the dose threshold that causes functional impairment. This suggests that patients can preserve fertility without the need for gonadal occlusion or pre-radiation sperm banking.

Research on soil-to-plant transfer factor of ²³⁸U, ²³²Th, ²²⁶Ra, ¹³⁷Cs in Sympegma regelii Bunge from Beishan

LING Hui, XIA Zitong, ZHAO Wei, MA Mingqing, WU Peng

RADIATION PROTECTION. 2025, 45(4):  410-418. 

Abstract ( 25 )   PDF (8914KB) ( 16 )  

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The transfer factor of radionuclides from soil to plants is one of the most important parameters in the biosphere assessment model of high-level radioactive waste disposal. The value and uncertainty of the transfer factors have significant impact on the assessment results. In order to obtain the transfer parameters and uncertainty level for the site of Beishan underground research laboratory, the dominant plant type plant Sympegma regelii Bunge was selected to carry out a preliminary study on the radionuclides transfer factor of soil to plant. In this paper, the natural radionuclides ²³⁸U, ²³²Th, ²²⁶Ra and artificial radionuclides ¹³⁷Cs in representative soil samples and Sympegma regelii Bunge were measured and analyzed; the transfer factor and uncertainty level of nuclides from soil to roots, stems and leaves of Sympegma regelii Bunge were obtained. The results showed that the transfer factor of natural radionuclides ²³⁸U, ²³²Th and ²²⁶Ra in stems were generally higher than those in roots and leaves, while the transfer factor of artificial radionuclides ¹³⁷Cs in roots were significantly higher than those in stems and leaves. The fluctuation range of transfer factor of natural radionuclides ²³⁸U, ²³²Th and ²²⁶Ra was within 1 order of magnitude, while the fluctuation range of artificial radionuclide ¹³⁷Cs was up to 2 orders of magnitude. The fluctuation range of radionuclide transfer factor showed that the leaves were significantly higher than that in the stems and roots.

Effects of ¹³⁷Cs γ irradiation on Arabidopsis thaliana progeny

YUAN Han, QIAO Xinyan, CAO Shaofei, LI Jianguo, YU Zhixiang

RADIATION PROTECTION. 2025, 45(4):  419-427. 

Abstract ( 16 )   PDF (3368KB) ( 15 )  

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In order to evaluate the radiation impact of nuclear facilities on terrestrial ecosystems, and to explore the effects and biological mechanisms of γ radiation on the offspring of Arabidopsis thaliana, the Col-0 Arabidopsis thaliana was selected and irradiated at different dose rates (0 mGy/h, 10 mGy/h, 20 mGy/h, 50 mGy/h, 100 mGy/h). The plant height, leaf length, leaf width, chlorophyll content, superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione reductase (GR), malondialdehyde (MDA), proline (PRO), and chlorophyll fluorescence indicators were measured. The results indicated that there were differences in the growth and development of Arabidopsis thaliana progeny after irradiation. The overall plant height showed a trend of increasing first and then decreasing. Plant leaves, MDA, POD, and effective photochemical quantum yield were the minimum points after 50 mGy/h irradiation. The SOD and CAT specific activity were the lowest at 20 mGy/h. GR and PRO showed that the irradiated Arabidopsis thaliana offspring plants were significantly lower than the control group. The content of chlorophyll a and chlorophyll b in 10 mGy/h and 50 mGy/h irradiation was significantly lower than other treatments. The non-photoquenching coefficient tendency indicates that low-dose rate irradiation did not cause irreversible damage to the photosynthetic response center PS Ⅱ in the offspring of Arabidopsis thaliana. Plants mainly respond to ionizing radiation by regulating the antioxidant enzyme system and osmolyte substances.

Research progress on radiation dose and health effects on rescue workers and the public in the Fukushima accident

YANG Xue, XUE Xiangming, GU Xiaona, WU Xiaoyan, YANG Kai, ZHAN Jingming

RADIATION PROTECTION. 2025, 45(4):  428-436. 

Abstract ( 28 )   PDF (1144KB) ( 14 )  

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This article was based on the 2021 report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). In connection with other research results in recent years, the radiation dose and health effects on rescue workers and the public after the Fukushima nuclear accident were comprehensively analyzed. The results indicate that the maximum effective dose for workers and contractors at nuclear power plants after the Fukushima accident occurred in the first year of the nuclear accident, reaching 678.8 mSv and 238.4 mSv respectively. After April 2012, the doses for contractors were consistently higher than those for nuclear power plant workers. Except for the first year, the doses for contractors were all within the prescribed limit of 50 mSv/a. Between March and December 2011, 1,757 workers had thyroid accumulated absorbed doses exceeding 100 mGy, and it was estimated that 13 workers had thyroid accumulated absorbed doses exceeding 2 Gy. In the first year after the accident, the effective doses for the public in the non-evacuated areas ranged from 0.079 to 5.3 mSv, and thyroid doses ranged from 0.46 to 21 mGy. Both increased with decreasing age groups. The effective doses for the public in the first ten years were approximately 2 to 3 times that of the first year, and the lifetime doses were about 4 times higher. No clear health effects or deaths attributable to radiation exposure were observed among the personnel involved in the emergency response to the Fukushima accident. There is no evidence to suggest that the adverse health effects of the residents in Fukushima can be directly attributed to the radiation exposure from the Fukushima accident. It is important to improve the emergency radiation monitoring system, reserve emergency monitoring personnel, and pay attention to the baseline health monitoring of local residents near nuclear power plants.