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ABSTRACT: The paper provides a short historical overview of creation, usage and current radiation and hydrologic status of the Techa
reservoir cascade. The analysis is given of the reservoir water balance, main water flows and sources of radionuclide filtration
inflow from the TRC into the open hydrographic system of the Techa river.
It is demonstrated that the main problem of the TRC usage is related to the general tendency of water level growth in the
reservoirs, which results in the increase of radionuclide inflow into the Techa river with filtration drains and forms additional
hydrostatic load on the dam of the end cascade reservoir R-11.
Different options increasing safety of the TRC use currently implemented and planned for the future are analyzed.
12/2007: pages 163-174;
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V V Khokhryakov, E G Drozhko,
Yu V Glagolenko,
S I Rovny,
E K Vasilenko,
A Suslov,
L R Anspaugh,
B A Napier,
A Bouville,
V F Khokhryakov,
K G Suslova,
S A Romanov
Biophysik 04/2002; 41(1):33-5. · 1.70 Impact Factor
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ABSTRACT: The present paper describes results of the first independent evaluation of the accuracy of the dose-reconstruction technique by electron paramagnetic resonance using tooth enamel. Each of twenty-four teeth donated by Mayak nuclear workers with known occupational radiation exposure histories was cut into two parts so that each tooth could be shared for blind electron paramagnetic resonance examination by at least two of the four laboratories participating in the study. The mean difference (+/- SD) between electron paramagnetic resonance estimates of the paired samples of each tooth shared by the two laboratories in best agreement was 0.02 +/- 0.15 Gy. Mayak workers can be classified into two groups: modern workers (after 1961) having reliable official dose information and earlier nuclear workers whose dose information is less reliable because they were exposed mainly before 1961. Film badges did not contain filters until 1954. Doses in this earlier group are much higher (up to 5 Gy). Comparison of the electron paramagnetic resonance results with tooth doses calculated from official film-badge doses showed a close agreement for the first group, whereas in the second group, official doses appeared to be slightly higher than the electron paramagnetic resonance doses. The results suggested a possibility that the official doses were somewhat overestimated among the high-dose-exposed workers. Consequently, cancer risks derived from this high-dose group might tend to be slightly underestimated.
Health Physics 01/2000; 78(1):15-20. · 1.68 Impact Factor
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ABSTRACT: Dose-response relationships for alpha-radiation-induced lung cancers (adenocarcinoma, squamous carcinoma and small cell carcinoma) were developed by multifactorial analysis using data for Mayak nuclear enterprise workers chronically exposed by inhalation to 239Pu. The three most important lung cancer risk factors (smoking, plutonium incorporation, and external gamma irradiation), out of six factors previously identified, were used. Relative risks (odds ratios) were determined for 500 nuclear enterprise workers (162 cancer cases, 338 control) for different dose levels using a case-control study design and logistic regression. A threshold at about 3.7 kBq or 0.80 Gy was discovered for incorporated plutonium, which is satisfactorily described by linear-quadratic and quadratic models. Excess relative risk was 0.020 kBq(-2) and 0.97 Gy(-2). This quadratic function was mainly due to adenocarcinoma. A trend for decreasing risk was noted for the lowest levels of plutonium incorporation, near permissible level. No clear-cut dose-response relationship for lung cancer induction by chronic external gamma irradiation was obtained. Lung cancer induction by cigarette smoking had a linear dependence: smoking of one pack of papiroses (a type of Russian cigarette) per day for 5 y increases the lung cancer risk twofold. The effect was most clearly manifested for squamous-cell carcinoma.
Health Physics 01/1998; 73(6):899-905. · 1.68 Impact Factor
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ABSTRACT: For the estimation of radiation lung cancer risk for a human being it is important to take into account different etiological factors because of the polyetiology of this disease. This work was the aim of a retrospective investigation ("case-control") of 500 workers of a nuclear enterprise that had been gamma-irradiated in a wide dose range and had had exposure to airborne 239Pu. One hundred sixty-two persons contracted lung cancer (morbidity), and 338 persons that had not fallen ill served as pair control. Eleven potential risk factors were evaluated using a logistic regression model, five insignificant factors were excluded, and the remaining factors were arranged (by odds ratio) in decreasing order: smoking > plutonium pneumosclerosis > plutonium incorporation in body > chronic obstructive pulmonary diseases (COPD) > decrease of body mass > external gamma-irradiation. The percentage of histologically confirmed adenocarcinoma among the nuclear enterprise workers was 74%, which is significantly higher than 33% among the population that did not work at the enterprise, particularly in the case of high (more than 11 kBq) plutonium incorporation by the nuclear workers. The localization of tumors in this cohort is more frequently in the lower and middle lung lobes and at the periphery. Each of the histological types of lung cancer has manifested a different degree of correlation with particular factors. The adenocarcinoma has the most frequent correlation with the radiation factors; the odds ratio for plutonium incorporation and plutonium pneumosclerosis is 2.9 (95% CI = 1.0-8.4); for external gamma-irradiation the odds ratio is 1.9 (0.99-3.5); the odds ratio for smoking is 4.3 (1.9-9.9). The squamous-cell carcinoma has the highest correlation with non-occupational factors: with smoking the OR is 6.8 (1.2-38.7), with the chronic obstructive pulmonary diseases the odds ratio is 3.9 (1.8-8.4), and with body mass decrease the odds ratio is 2.1 (0.94-4.6); odds ratio for plutonium incorporation is 4.2 (1.4-12.8). The small-cell carcinoma has correlation with body mass decrease [odds ratio = 2.9 (1.2-7.6)] and high level of smoking [smoking index > 500; odds ratio = 3.5 (1.4-8.9)]. The portion of the occupational cancers among the workers of the nuclear enterprise, evaluated on the base of attributive risk, is 26%, with 57% for adenocarcinoma, 9% for squamous-cell carcinoma, and 8% for small-cell carcinoma. The investigation is continued to assess the dose-effect and factors interactions.
Health Physics 09/1995; 69(3):356-66. · 1.68 Impact Factor
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ABSTRACT: Mean annual occupational exposures are reported for radiation workers at the first Russian industrial nuclear facility 'Mayak', South Ural region, for the period 1948-1988. The underlying individual doses originate from the register of the in-plant radiation safety department and are based on local film dosimetry results. Differentiation is made between personnel working at reactor and radiochemical processing plants. Verification of summed film doses is performed by means of ESR dose reconstruction using extracted teeth from selected individuals. Explanations are given for observed discrepancies between the reconstructed individual doses and original integrated film dosimetry results. The research potential of combined dose information from specific tooth enamel and dentine are shown.
Applied Radiation and Isotopes 47(11-12):1277-80. · 1.17 Impact Factor
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ABSTRACT: Mean annual occupational exposures are reported for radiation workers at the first Russian industrial nuclear facility ‘Mayak’, South Ural region, for the period 1948–1988. The underlying individual doses originate from the register of the in-plant radiation safety department and are based on local film dosimetry results. Differentiation is made between personnel working at reactor and radiochemical processing plants. Verification of summed film doses is performed by means of ESR dose reconstruction using extracted teeth from selected individuals. Explanations are given for observed discrepancies between the reconstructed individual doses and original integrated film dosimetry results. The research potential of combined dose information from specific tooth enamel and dentine are shown.
Applied Radiation and Isotopes.
