[en] Except of usual for all countries natural background, radon in buildings, medical check-up, etc., the population of the Republic of Belarus receive additional irradiation, concerned with Chernobyl accidence. Analysis of the annual data shows the reduction of the annual effective dose equivalent, received by population from after-Chernobyl contamination, that in the regions under control is about 1 mSv. In such conditions dose, received by population of Belarus during diagnostic radiology procedures, becomes important. According to published data average effective dose equivalent, received by population of Belarus in 1989, is about 1.3 mSv per inhabitant. This value is comparable with doses, received from the radioactive contamination, and consist of several parts: 0.7 mSv is received from fluoroscopy, 0.3 mSv - from radiography, and 0.4 mSv - from fluorography. The largest dose during check-up procedures received thorax organs (0.64 mSv) and alimentary canal (0.59 mSv). If situation will remain the same, diagnostic radiology check-up procedures will result in 14 000 cases of cancer during 30 years. Estimation of after-Chernobyl radiation induced cancer gives 10 time less value. Above data about doses during diagnostic radiology procedures are needed to be confirmed experimentally and comprehended theoretically. The set of scientific investigations for determination of patient doses during diagnostic radiology check-up procedures in Belarus are carrying out. The purpose of our investigations is to work out the method of determination of the effective doses on separate organs and total body of patients during such diagnostic radiology procedures as fluoroscopy, radiography, mammography and computer tomography. The results of our investigation can be used in the field of public health of the Republic of Belarus in three ways. First, to check the quality of used X-ray equipment. Second, for working out new methods of diagnostic check-up procedures with reduced dose per patient but with the same quality of received information. Third, to organize in Belarus the country register for doses, received by patients during diagnostic radiology procedures

[en] The paper presents the results of the reconstruction of external and internal exposure to the inhabitants of Belarus during 1986, who lived in the areas contaminated with a cesium 137 level exceeding 0.185 MBq*m^-2 (5 Ci*km^-2), on the basis of statistical analysis of the database on radiation monitoring of the environments, foodstuffs, and individual control. The database was created in the Institute of Biophysics with the help of radiological services and scientific Institutes of Belarus. About 1580 settlements with 414,000 residents (including 247,000 in the zone of evacuation) were located onto that territory. The model of 'basic' distribution was suggested. The dose distribution was estimated for evacuated and non evacuated residents in 1986 on the basis of the mentioned model, taking into account countermeasures. The obtained results are compared with the earlier received express estimates used in making the decisions as well as with the tendencies of radiation situation formation in near-by areas in Russia. The collective dose for the population, who lived in the territory contaminated with a cesium 137 level exceeding 0.185 MBq.m^-2 (including the zone of evacuation), is estimated to be equal to 4300 man Sv. Non realised dose in 1986 is estimated to be equal to 3500 man.Sv and the main effect (72%) was due to evacuation of the residents. The average estimate of the individual doses for different zones of contamination varied from 6.5 mSv to 32 mSv and totally for all the considered territory was equal to 10.4 mSv. For 78% of the inhabitant s external exposure didn't exceed 10 mSv, and for 1.3% and 0.27% of the inhabitants that exposure exceeded 50 mSv and 100 mSv, respectively. For 99.2% of the inhabitants internal exposure didn't exceed 10 mSv, except for 0.027% of the inhabitants (approximately 110 people) that exposure exceeded 50 mSv. (authors)

[en] Correct assessment and prediction of doses in population is one of the most actual and complex problems of radiation medicine. Apparently great amount of models has been developed so far to evaluate average doses. But for the actual (real) doses estimation within a settlement this is not enough: it is necessary to estimate distribution on the whole, as the accuracy of these models is insufficient and the application of the above models does not answer the designed tasks. At the same time decision support strategies of countermeasures application are always based on the prediction of doses received in the areas affected by contamination. The original method for estimation of the external and, than, the total doses distributions on the known internal dose distribution is presented. This method is based on the hypothesis of the genetic relationship between the external and internal doses, received in rural inhabitants, because the representatives of the separate population groups demonstrate similar 'behaviour' in the radiation field. Algorithm of the task is to recognize the population groups of similarity in the settlement on the basis of the informative factors (method of classification). The method proves that the close relationship between external and internal doses exists, but only - within classes of similarity. The external dose distribution in the inhabitants of Kirov town was reconstructed. The comparison of this distribution with the distribution, received using TLD, shows that they are very close in terms of statistical parameters. The total dose distribution was received for inhabitants of the Kirov settlement using measured internal doses and predicted external doses with the following evaluation of its parameters. Proposed method allows to optimize and to increase the correctness (the error does not exceed 30% ) of the evaluation of doses in the rural population. (authors)

[en] This report provides guidance to a verifier on reviewing of programs for safety systems written in the high level languages, such as Ada, C, and C++. The focus of the report is on programming, not design, requirements engineering, or testing. We have defined the attributes, for example, reliability, robustness, traceability, and maintainability, which largely define a general quality of software related to safety. Although an extensive revision to the standard of Ada occurred in 1995, current compiler implementations are insufficiently mature to be considered for safety systems. The discussion on C program emphasized the problem in memory allocation and deallocation, pointers, control flow, and software interface. (author). 26 refs

[en] The ICH/FWCD system for KSTAR shall initially be configured to provide 6 MW power to the plasma with one antenna. The system can be upgraded to provide 12 MW of power to the plasma with the addition of a second system that is duplicate of the first. The initial KSTAR ion cyclotron system consist of one port-mounted antenna that have four current straps. Each strap, using appropriate tuning, matching, and decoupling circuitry will be driven by an independent rf power source. The goal of this ICH/FWCD system is to deliver up to 6 MW of power to the plasma under a variety of plasma conditions. In this report, the plasma loading for various plasma conditions is computed by RANT3D code; electric property of antenna, i.e. inductance, capacitance and mutual coupling are examined; and then a brief description of the overall ICH/FWCD system is given. (author). 3 refs., 4 tabs., 25 figs

[en] This work presents two approaches for reflector simulation in coarse-mesh nodal methods. The first approach is called Interface Matrix Technique (IMT), which simulates the baffle as a banishingly thin layer having the property of reflection and transmission. We applied this technique within the frame of AFEN (Analytic Function Expansion Nodal) method, and developed the AFEN-IM (Interface Matrix) method. AFEN-IM method shows 1.24% and 0.42 % in maximum and RMS (Root Mean Square) assemblywise power error for ZION-1 benchmark problem. The second approach is L-shaped reflector homogenization method. This method is based on the integral response conservation along the L-shaped core-reflector interface. The reference reflector response is calculated from 2-dimensional spectral calculation and the response of the homogenized reflector is derived from the one-node 2-dimensional AFEN problem solution. This method shows 5 times better accuracy than the 1-dimensional homogenization technique in the assemblywise power. Also, the concept of shroud/reflector homogenization for hexagonal core have been developed. The 1-dimensional spectral calculation was used for the determination of 2 group cross sections. The essence of homogenization concept consists in the calculation of equivalent shroud width, which preserve albedo for the fast neutrons in 2-dimensional reflector. This method shows a relative error less than 0.42% in assemblywise power and a difference of 9x10^-5 in multiplication factor for full-core model. (author). 9 refs., 3 tabs., 28 figs

[en] The development of high efficiency filter was started to protect human beings from the contamination of radioactive particles, toxic gases and bacillus, and its gradual performance increment led to the fabrication of Ultra Low Penetration Air Filter (ULPA) today. The application field of ULPA has been spread not only to the air conditioning of nuclear power facilities, semiconductor industries, life science, optics, medical care and general facilities but also to the core of ultra-precision facilities. Periodic performance test on the filters is essential to extend its life-time through effective maintenance. Especially, the bank test on HEPA filter of nuclear facilities handling radioactive materials is required for environmental safety. Nowadays, the bank test technology has been reached to the utilization of a minimized portable detecting instruments and the evaluation techniques can provide high confidence in the area of particle distribution and leakage test efficiency. (author). 16 refs., 13 tabs., 14 figs

[en] A wide variety of thin film coatings, deposited by different techniques and with potential applications in various important areas, have been characterised by the Phase Modulated Spectroscopic Ellipsometer, installed recently in the Spectroscopy Division, B.A.R.C. The Phase Modulated technique provides a faster and more accurate data acquisition process than the conventional ellipsometry. The measured Ellipsometry spectra are fitted with theoretical spectra generated assuming an appropriate model regarding the sample. The fittings have been done objectively by minimising the squared difference (χ²) between the measured and calculated values of the ellipsometric parameters and thus accurate information have been derived regarding the thickness and optical constants (viz, the refractive index and extinction coefficient) of the different layers, the surface roughness and the inhomogeneities present in the layers. Measurements have been done on (i) ion-implanted Si-wafers to investigate the formation of SiC layers, (ii) phenyl- silane coating on glass to investigate the surface modifications achieved for better adsorption of rhodamine dye on glass, (iii) GaN films on quartz to investigate the formation of high quality GaN layers by sputtering of GaAs targets, (iv) Diamond-like-coating (DLC) samples prepared by Chemical Vapour Deposition (CVD) to investigate the optical properties which would ultimately lead to an accurate estimation of the ratio of sp³ and sp² bonded carbon atoms in the films and (v) SS 304 under different surface treatments to investigate the growth of different passive films. (author)

[en] Nuclear power industry has a quite long tradition in on-line diagnostic of mechanical components and a considerable effort was put in developing diagnostic systems which are able to detect arising mechanical problems at an early stage. Computers are increasingly exploited to provide higher level information on process behaviour such as: early indication of the process deviation from normal conditions; rapid identification of the cause of any disturbance; prediction of the evolution of a disturbance; operator aid through computerized help. Following the recommendation of Several Member States to strengthen the activity in this field two divisions of IAEA established in 1995 the International Task Force on Nuclear Power Plant Diagnostics. The scope of the task force cover both technological developments and safety/licensing aspects of diagnostics. This report contains papers presented at the last in the series of Technical Committee Meetings on the Diagnostic Systems in Nuclear Power Plants organized in the framework of International Task Force

[en] Nuclear Power Plant (NPP) surveillance and fault diagnosis systems in Dutch Borssele (PWR) and Dodewaard (BWR) power plants are summarized. Deterministic and stochastic models and artificial intelligence (AI) methodologies effectively process the information from the sensors. The processing is carried out by means of methods and algorithms that are collectively referred to Power Reactor Noise Fault Diagnosis. Two main schemes used are failure detection and instrument fault detection. In addition to conventional and advanced modern fault diagnosis methodologies involved, also the applications of emerging technologies in Dutch reactors are given and examples from operational experience are presented. (author)