关于水源中放射性核素浓度标准问题

本文讨论了内照射剂量限制标准的发展。指出将水中放射性核素浓度作为内照射剂量限制标准的局限性。但是,对于环境管理,把它作为环境污染水平的管理限值还是有意义的。本文还讨论了推导管理限值的方法,认为考虑到关键途径和关键居民组的浓度因子法是一种合适的方法。     

Radiation safety norms for atomic energy

The evolution of the dose limit and the admissable concentration of radionuclides in air and water in regulatory documents is analyzed. The legitimacy of classifying liquid radioactive wastes on the basis of the intervention level for radionuclide concentrations in drinking water is discussed. The SP AS-99 admissable irradiation levels for the general population due to emissions for nuclear power plants are compared with the dose in regions containing nuclear and thermal power plants.Translated from Atomnaya Ènergiya, Vol. 97, No. 4, pp. 299–308, October, 2004.     

Computer Code System DSOCEAN for Assessing the Collective Dose of Japanese due to Radionuclides Released to the Ocean from a Reprocessing Plant

A computer code system DSOCEAN has been developed for assessing the collective dose of Japanese due to radionuclides released to the ocean from a spent nuclear fuel reprocessing plant. This computer code system uses a box model which represents the transfer of radionuclides between boxes of seawater into which the ocean around Japan is divided. The code system consists of a series of three interlinked main computer codes, which estimates the exchange rates of radionuclides between the boxes, the radionuclide concentrations in each box, and the collective dose from various exposure pathways, respectively.

By using DSOCEAN, two calculations were carried out to estimate the collective dose from a liquid effluent. One is associated with a routine release of radionuclides from a hypothetical reprocessing plant. The other is an application of the code system to disposal of liquid radioactive waste to the surface water of the ocean. The calculated results identified important radionuclides and exposure pathways.     

Dose Loads on Hydrobionts and the Population Living in the Operational Regions of Nuclear-Powered Ships

Data accumulated over many years of observations of radioecological conditions are used to analyze the accumulation coefficients for technogenic radionuclides in hydrobionts in interior bukhtas and zalivs in the north-western part of the Sea of Japan. Attention is focused on estimating the contribution of technogenic radionuclides to the dose according to their accumulation coefficients in marine biota and to determine more accurately the contribution of natural ⁴⁰K to the total dose in the operational regions of nuclear-powered ships. On individual local sections of bukhtas and zalivs, the dose due to external irradiation from technogenic radionuclides in bottom deposits exceeds the natural level (regions of radiation accident in bukhta Chazhma, near the nuclear-powered submarine with the damaged nuclear power system in bukhta Pavlovskogo). However, the total dose due to technogenic irradiation of hydrobionts as a whole remains low and falls outside the dose range at which negative effects of radiation for marine organisms are observed.     

Incident Angle Dependence of Residual Defect in Silicon Surface Barrier Detector

The fate of radionuclides produced in a light water moderator was investigated by assaying with a Ge(Li) detector sampled coolant water and the waste water produced by regeneration of resins, measuring the radiation dose rates along the surface of the resin column length with TLDs, and studying the sorption of radionuclides to resins in dynamic experiments. The buildup concentrations of short-lived radionuclides, produced by activation in the reactor core water and the amounts of radionuclides sorbed on the resin bed, as estimated from a compartment model, are reported. A method for estimating the production rate of soluble radionuclides with long half-lives in the core water has been developed. Changes in the radiation dose rates along the resin column length recorded during reactor operation and after shut-down, showed that the sorbed radionuclides did not migrate downward, as expected from the chromatography theory, rather they were decreased by the decay process. Moreover, the slopes of the dose rates on both sides of the resin surface were almost identical. These results show the behavior and distribution of radionuclides in the light water moderator of a research reactor.     

Prediction of the radiation effect resulting from the contamination of water in marine fisheries

The planning and implementation of various projects involving possible radioactive contamination of seawater require a prediction of the effect of radiation on the public. The main pathway for a radiation effect is the consumption of seafood from contaminated fisheries. A method is proposed for assessing the radiation effect due to the consumption of seafood. A special feature of the method proposed is that it uses dose coefficients to convert the volume activity of seawater in the area of a fishery into the effective irradiation dose to an individual from the general public. The computed dose coefficients for 57 radionuclides and seven types of seafood are presented. __________ Translated from Atomnaya énergiya,Vol. 100, No. 2, pp. 83–86, February, 2006.     

Radiological habitability evaluation of the control room of the high-temperature reactor pebble-bed module: post-accident dose assessment and sensitivity studies

The radiological habitability of a control room is important for nuclear emergency response, which is also a licensing prerequisite for nuclear power plants. It is determined by both atmospheric relative concentrations and doses received via different pathways. However, most recent studies have focused only on the former, which may not be adequate. The present study therefore investigates the radiological habitability and its sensitivity to different parameters in the high-temperature gas-cooled reactor pebble-bed module power plant. For three typical accidents, the study estimates the body, thyroid and skin doses received via different pathways using the Nuclear Regulatory Commission recommended ARCON96 and dose calculation method in RG 1.195. To make a realistic evaluation, the latest design and site-specific information, including the unique accidental source term, are collected and used as input parameters. The evaluation results reveal that the total dose of different pathways in the control room is far below the limit, which demonstrates the effectiveness of the current design. The inhalation exposure is the dominant pathway, and iodine and caesium are the primary contributors of the inhalation dose. The particle filter removal fraction is the most influential parameter in an accident which the activities of metal radionuclides are high.     

γ辐射加工中剂量控制技术研究

针对γ辐射加工过程中的剂量控制问题,结合某单位现有的单板源动态γ辐照装置特点,系统分析了影响剂量控制水平的因素,从剂量测量体系建立和辐照装置改进两方面开展了辐照剂量控制技术研究。通过大量剂量测试和统计分析,检验评估了整个辐射加工过程中的剂量控制能力。结果表明:剂量测量体系标准化和辐照装置优化改进,很好地控制了辐照稳定性和剂量不均匀度,显著提高了产品辐照剂量的控制水平,对辐射加工生产具有指导意义。     

Setting standards for the safe level of radioactive contamination of water and bottom sediments in bodies of water

In this paper, we propose standards which can be used to simply and reliably monitor the content of technogenic radioactive substances in rivers and other bodies of water. We introduce the concept of “maximum safe concentration” and “reference monitored concentration” of radionuclides in water, and also the “maximum concentration of radionuclides in bottom sediments.” To determine the maximum safe concentration of radionuclides in water, we have used the basic public health principle established in NRB-96: to not exceed the limit of an effective dose of 1 mSv/y for external and internal radiation exposure for a critical population group, considering overall water use. To define the degree of radioactive contamination of the bottom of bodies of water, we propose using the maximum concentration of radionuclides in bottom sediments: a concentration less than that for which the bottom sediments may be classified in the category of “low activity solid radioactive wastes” according to OSP-72/87. We offer a calculation scheme and numerical values for the proposed standards for some radionuclides most frequently encountered in practice and examples of their use. State Institute of Applied Ecology NPO Taifun. Translated from Atomnaya énergiya, Vol. 86, No. 5, pp. 398–407, May, 1999. Original article submitted December 30, 1998.     

天津市地下水和地热流体中天然放射性核素调查与评价

对天津市地下水和地热流体中的天然放射性核素活度浓度水平进行调查,并根据调查结果评价天津市居民因饮用地下水和地热流体所致的内照射剂量。调查结果显示天津市地下水和地热流体中的天然放射性核素活度浓度属正常水平,未发现放射性水平异常状况。     

Radiation Conditions in Obninsk

Monitoring data are used as a basis to examine the radiation conditions in Obninsk, including an analysis of the radioactive emissions from the Physics and Power-Engineering Institute and the Scientific-Research and Physicochemical Institute, the content of technogenic radionuclides in atmospheric air, soil, surface waters, and the components of agricultural natural ecosystems, and an estimate of the dose and radiation risk to the public. The monitoring results show relatively low levels of technogenic radionuclides in the environment, much lower than the admissable values. It is recommended that regular radiation monitoring of the content of tritium in surface and underground waters and also iodine isotopes in air near the ground at Obninsk be continued. The total estimated dose, taking account of numerous pathways of technogenic irradiation of the public in Obninsk, is on the average about 10⁻⁵ Sv/yr, which corresponds to a negligibly low radiation risk, less than 10⁻⁶ under standard operating conditions of nuclear objects. __________ Translated from Atomnaya Energiya, Vol. 99, No. 3, pp. 214–221, September, 2005.     

Annals of the ICRP. A report of: doses to infants from ingestion of radionuclides in mothers' milk

In the present report, ICRP provides information on radiation doses to the infant due to intakes of radionuclides in maternal milk. As in Publication 88 (ICRP, 2001) on doses to the embryo and fetus following intakes of radionuclides by the mother, intakes by female members of the public and female workers are addressed. Acute and chronic intakes are considered at various times before and during pregnancy as well as during the period of breastfeeding. Dose coefficients per unit intake by the mother (Sv/Bq) are given for the selected radionuclides of the same 31 elements for which age-specific biokinetic models were given in Publications 56, 67, 69, and 71 (ICRP, 1989, 1993, 1995a,b). For these elements, doses were calculated for the most radiologically significant natural or artificial radionuclides that might be released into the environment due to various human activities. Dose coefficients are also given in this report for radionuclides of an additional four elements: sodium, magnesium,phosphorus, and potassium. Relevant human and animal data on elemental and radionuclide transfer to milk are reviewed. The biokinetic models for adults given in earlier ICRP publications are adapted to include transfer to milk. Model predictions of fractional transfer of ingested or inhaled activity to milk are discussed in the report, and the corresponding dose coefficients for the infant are compared with dose coefficients for in utero exposure, as given in Publication 88 (ICRP, 2001). Illustrative information is also given on doses to the female breast from radionuclides in breastmilk, and external doses received by the child from radionuclides retained in the tissues of the mother. For the additional elements considered in this report, but not in Publication 88 (ICRP,2001), information is also given on doses to the embryo and fetus following maternal intakes of radioisotopes during or before pregnancy. A CD-ROM is to be issued giving data that will supplement the information given in this report. In addition to the dose coefficients given here, committed equivalent doses to the various organs and tissues of the offspring will be given. Dose coefficients will also be given for inhalation of a range of aerosol sizes for the selected radionuclides of the elements covered by this report.     

Monte-Carlo study of induced radioactivity in probe for low-energy proton beam

Induced radionuclides generated from the probe which is bombarded by proton beam will turn the detector into a typical external irradiation radiation source. Thus, it is beneficial for developing radiation protection to calculate the types and the activities of radionuclides. Here we applied both a theoretical analysis and a Monte-Carlo method to compute the induced radioactivity in a copper probe irradiated by proton beam. Various kinds of radionuclides saturation activity obtained by these two different methods were compared. The comparisons of the results cast by the two methods show the similar saturation activities for ⁶³Zn and ⁶⁵Zn. However, the Monte-Carlo method conducted by the software FLUKA is able to provide a more complete consideration on nuclear reaction, and to calculate both the direct and indirect radioactivity under different irradiation time. Furthermore, by employing the FLUKA Monte-Carlo program, the induced radioactivity of three types of probe materials (Cu, Ta and W) under low-energy (below 20 MeV) proton beam irradiated were also separately simulated and tantalum is considered as the best material for low-energy proton interceptive diagnostics probe due to the higher energy threshold of nuclear reaction and the lower radioactivity.     

辐射技术制备聚丙烯酸/高岭石吸水凝胶

Superabsorbent polyacrylic acid/montmorillonite composite (SAPC) with high water absorption capacity prepared using 9 MeV electron beam irradiation is presented in this paper, which is different from others in material composition and preparation method.     

降雨途径中农作物对核素的截获行为研究现状

核设施运行过程中, 排放的气载放射性核素沉积到土壤或农作物表面并进入食物链, 是计算公众内照射剂量的主要来源, 大气湿沉积-降雨过程中农作物对核素的生态转移过程涉及截获和易位行为。本文调研了国内外降雨途径中农作物对核素截获行为的研究现状, 包括农作物种类、实验方法、影响因素和转移参数, 结合我国现状, 提出了此领域的研究方向和重点。     

Level of natural radionuclides in foodstuffs and resultant annual ingestion radiation dose

The natural radioactivities in three major groups of foodstuff widely consumed in Upper Egypt were determined. The specific activities of ^226Ra, ^232Th, and ^40K in cereals, leguminosae, and flour were measured using γ-ray spectroscopy. Another group of hay, water, and soil samples from the same location were also analyzed. Hay samples were found to contain the highest radioactivity concentration among all the samples that were investigated. This increment could be due to the high water content in the shoots which tends to accumulate soluble radionuclides. The average calculated concentrations of soil samples in the present study exhibits the lowest values with respect to those from different countries. In the case of water samples, the average activities of both ^232Th and ^40K were similar to those for soil while ^226Ra was twice that of water sample. The annual ingestion dose from each radionuclide was calculated. The computed annual dose owing to daily intake of radium, thorium, and potassium via wheat flour, lentils, and bean in the present study （214.8 μSv） is ten times lower than the global average annual radiation dose （2400 μSv） from the natural radiation sources as proposed by UNSCEAR. The obtained results show that the dose values are quite low and carry insignificant radiation dose to the public.     

公众成员某些放射性核素的吸入有效剂量系数

本文根据ＩＣＲＰ７１号出版物，给出了３１个元素的７４个放射性核素对公众的吸入有效剂量系数，并对它们的应用进行了简要讨论。这些核素是由于各种人类活动可能释放环境中去的并在环境辐射防护方面有重要意义的核素。     

保健茶辐射消毒剂量的保持和辐射抗性的研究

以某种保健茶为例,通过检测其细菌及霉菌的表观D10值,确定其辐射消毒剂量,并依据由25组初始污染数据建立的控制图监视此后各生产批次初始污染变化,判断其辐射消毒剂量是否持续有效。这种方法较之单纯使用公式法确定剂量节省成本,且对其他类相关产品如何保持其辐射消毒剂量起到了借鉴作用。     

Method for performing rapid radiation surveys of the water areas at shore bases of the naval fleet using submersible gamma spectrometers

A method of performing radiation surveys of the water areas at shore bases of the naval fleet using underwater scintillation gamma spectrometers is presented as an example of work performed in the waters near the temporary storage site for radwastes and spent fuel in Gremikha. This method makes it possible to record in situ from a surface ship as well as underwater manned or unmanned vehicle the content of radionuclides in sea water. In contrast to conventional methods of monitoring the radiation conditions by means of dosimetric surveys and sampling, submersible spectrometric systems make it possible to detect and identify rapidly the source of radioactive contamination in water and bottom deposits and to determine it size, intensity, and isotopic composition. Appropriate software is used to construct from the survey results cartograms of the contamination in the regions examined, identify pathways for radionuclides to enter the waters, and evaluate the total activity of the bottom deposits.     

Recent advances in medical radionuclide production and future perspective of compact medical cyclotrons

In recent years, many radiopharmaceuticals bearing different kind of radionuclides have been largely used in diagnostic and therapeutic studies, especially of cancer. The basic principle of radiodiagnosis and raditherapy is ensuring as low as radiation dose absorption by patients. Sometimes, the radionuclides having very short half-lives, and very interesting decay characteristics are required for this purpose. The use of short-lived radionuclides necessitates their productions just at the application sites. This necessity has provoked the development of compact particle accelerators. Nowadays, the radionuclide applications in diagnostic and therapeutic nuclear medicine are continuously escalation, and future perspective of these applications will strongly be depended on two important factors as being 1) increasing the variety of cyclotron-produced radionuclides, 2) design of new radiopharmaceuticals having different and specific metabolic pathways in normal and cancer tissues. For improvement of the first factor, new nuclear reactions should eventually be examined using new target materials. In this context, the targeting chemistry will be an essential role in this field. As the second factor, improvement of new radiopharmaceuticals will strongly be dependent on the biofunctional researches of new chemical agents and development of their radiolabeling techniques. The radionuclide production has evidently become more and more easy by using the compact medical cyclotrons. For this reason, the application of different radionuclides will be able to have an important role in the future either for scientific and technical applications or medical diagnostic and therapeutic studies. As a consequence of this progress, the basic nuclear scientists, especially nuclear and radiopharmaceutical chemists will be seeking professionals in the next new century.