Estimation of intakes of 131I, 137Cs and 134Cs after the Chernobyl accident

Activities of (131)I and (137)Cs excreted in urine from two healthy males during May 1986, when contaminated air masses from Chernobyl arrived on the territory of the Czech Republic, were determined by bioassay. The data were used to estimate the intakes and committed effective doses from these radionuclides. The results for inhalation intakes are of particular interest, in the absence of sufficient contemporary data for airborne activity. They are found to be higher than initial estimates based on air sampling.     

Distribution of tritium in water vapour and precipitation around Wolsung nuclear power plant

The distribution of tritium in water vapour and precipitation with discharge of tritiated water vapour and meteorological factors was studied around the Wolsung nuclear power plant (NPP) site during the period 2004-2008. The tritium concentrations in atmospheric water vapour and precipitation had a temporal variation with relatively high values in the early summer. Spatial distribution of tritium concentrations was affected by various factors such as distance from the NPP site, wind direction, tritium discharge into the atmosphere and atmospheric dispersion factor. The annual mean concentrations of atmospheric HTO and precipitation were correlated with the amount of gaseous tritium released from the Wolsung NPP. The tritium concentrations in precipitation decrease exponentially with an increase of the distance from the Wolsung NPP site.     

Population dose from indoor gamma exposure in the dwellings around Kudankulam nuclear power plant

To assess the population dose due to the natural background radiation around the upcoming Kudankulam nuclear power plant, a systematic investigation has been carried out by measuring the indoor gamma dose. In total, 159 dwellings have been selected around the Kudankulam nuclear power plant area i.e. in Radhapuram and Nanguneri taluk (sub-districts) for the measurement. The geometric mean value of indoor gamma dose rate is 305 +/- 48 nGy h(-1) and 273 +/- 50 nGy h(-1) in Radhapuram and Nanguneri taluks (sub-districts), respectively. The annual effective dose due to indoor gamma radiation to the population has been found to be 1.5 mSv and 1.36 mSv in Radhapuram and Nanguneri taluks, respectively.     

Intercomparison of whole-body counters by using a subject who had incorporated 137Cs into the body

During the years 1996-2000, eight whole-body counting facilities (WBC) from Finland, Germany, Japan and Russia took part in an intercomparison using a resident of the Russian town of Novozybkov who had been seriously contaminated as a result of the Chernobyl accident. The subject R (adult male, height 172 cm average body mass 64 kg; and 137Cs body burden within the range of 1-15 kBq) was investigated in the participating institutions during his business trips. The experimentally obtained data for his 137Cs body burden were compared with the predicted values, which had been deduced from the measurements of subject R using the reference WBC (St Petersburg Institute of Radiation Hygiene) and from his effective half-time of 137Cs in the body (68 days). The obtained results did not deviate more than 20% from reference activities. Four facilities were able to quantity the 40K in the subject's body. The differences between reported values of potassium did not exceed 10%. For subject R, the average annual effective dose from radiocaesium was 0.25 mSv and it was 0.18 mSv from 40K in the years 1996/97. The reliability of using a subject with naturally incorporated artificial radionuclides ('walking standard') instead of an anthropomorphous phantom for calibration and intercomparison of whole-body counters in a large-scale nuclear accident is discussed.     

Measurement of energy and directional distribution of neutron fluence inside a nuclear power plant

A detailed analysis of the neutron radiation field was performed at selected positions inside the Krümmel boiling water reactor. The measurements were performed with the PTB Bonner sphere spectrometer and with a newly developed directional neutron spectrometer based on silicon detectors mounted onto the surface of a 30 cm diameter polyethylene sphere. Both, angle-integrated and angle-differential spectral neutron fluences were determined in this way.     

将核电站反应堆置于地下的设想

由日本福岛核电站核泄漏事故设想,如果把核电站的反应堆置于山体内(即地下),当核泄漏发生,可将其封闭在地下洞室内,从而防止核泄漏扩散。当今水电站的厂房大部分置于地下,地下发电厂房在长期的建设实践中积累了丰富的地下工程施工经验,在技术上具有完全的可操作性;水电站地下厂房单位体积土建工程造价约600~1 500元/m3,经济上具有合理性;圆筒形的核岛(安全壳)体形可有效降低围岩应力,岩体结构具有安全性;地下厂房具有远优于地面厂房的抗震性;地下核电站在选址上还占有优势,可节约农耕用地,减少对居民生活的影响。通过成熟的工程处理措施,地下核电站的密闭性、冷却水、地下水污染等问题均可得到妥善处理。更进一步地设想,可把水电站与核电站组合在一起,从而形成强大的、无排放的清洁电源。综合我国未来的能源需求以及当前核电发展的困境,地下核电站则是一个可取的选择。     

Measurement of thermal fluxes in power plant components

A method of recovering the thermal flux acting on a sensing element with respect to measurements of sensing element signals is described.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 48, No. 6, pp. 990–994, June, 1985.     

Determination of 137Cs in seawater under the field conditions

To monitor ¹³⁷Cs in seawater, Mikoton-Cs used for Cs sorption from highly saline liquid radioactive wastes was proposed. Sorption of ¹³⁷Cs on Mikoton-Cs was studied in relation to the S: L ratio, sorption time, and the temperature. The sorbent amount required to obtain a representative sample was determined. Two analytical procedures suitable for cesium determination under the field conditions were proposed.     

Occupational exposures of nuclear power plant workers in Finland

In Finland, the Radiation and Nuclear Safety Authority (STUK) maintains a central dose register where all occupational doses of radiation workers are recorded. The computerised register enables easy control of personal doses, including annual, 5 year and lifetime doses. The type of radiation work is also recorded in the dose register. Finland was one of the first countries in the world to introduce dose limits based on the recommendations of ICRP 60. In this article, the radiation dose data of the Finnish nuclear power plant workers are analysed. The majority of the radiation doses are received during the maintenance outages. The trend of the 5 year doses and their distribution are presented. Doses received during different work assignments were averaged over the years 1996-1999 and they are also discussed in this article.     

Organizational processes and nuclear power plant safety

This paper describes an integrated effort to define and measure organizational factors related to nuclear power plant safety. The research began by reviewing previously conducted studies looking at nuclear power operations and operations in other high reliability industries for indications of common safety-related, performance dimensions. Having established a list of 20 common dimensions, the project went on to fully define these dimensions and develop methods for their assessment. The methods of assessment developed for this application were employee survey—a series of self report questions answered by employees, behavioral checklist—sets of statements about the plant and its operations that observers respond to by answering yes or no, structured interview—a set of questions and interviewer asks of an employee and built around the 20 dimensions identified, and behaviorally anchored rating scales—an extension of the methodology used for assessing the performance of individuals to the process of assessing a nuclear power plant. Each of the methodologies is described as it applies to the assessment within the nuclear power environment and examples of each method are presented. Pilot tests of the feasibility of using these assessment methods were conducted in two nuclear power plants and the results are encouraging both in terms of the immediate identification of potential safety issues and as valuable additions to probabilistic risk assessment. Implications of this work for the future assessment of organizational factors related to nuclear power safety are discussed.