A study of the protective actions for a hypothetical accident of the Bushehr nuclear power plant at different meteorological conditions

Radiation and Environmental Biophysics - In this work, protective actions have been studied assuming a hypothetical severe accident of the Bushehr nuclear power plant at different meteorological...     

Karyopathological traits of thyrocytes and exposure to radioiodines in Belarusian children and adolescents following the accident at the Chernobyl nuclear power plant

The Belarus-American (BelAm) thyroid study cohort consists of persons who were 0-18 years of age at the time of exposure to radioactive iodine fallout from the 1986 Chernobyl nuclear power plant accident and who have undergone serial thyroid screenings with referral for fine-needle aspiration biopsy (FNAB) using standardized criteria. We investigated thyrocyte nuclear abnormalities in cytological samples from FNABs in 75 BelAm subjects with single and multiple thyroid nodules and 47 nodular goiter patients from Leningrad, Russia, unexposed to Chernobyl fallout. Nuclear abnormalities examined included internuclear chromosome bridges and derivative nuclei with broken bridges (i.e., "tailed" nuclei), which are formed from dicentric and ring chromosomes and thus may be cellular markers of radiation exposure. Among subjects with single-nodular goiter, thyrocytes with bridges were present in 86.8% of the exposed BelAm cohort compared with 27.0% of unexposed controls. The average frequency of thyrocytes with bridges and with tailed nuclei was also significantly higher in the BelAm subjects than in controls. Among subjects with multinodular goiters, thyrocytes with bridges were present in 75.7% of exposed BelAm patients compared with 16.7% of unexposed controls; thyrocytes with tailed nuclei were observed in all of the BelAm subjects but in only 40% of controls, and the mean frequencies of bridges and tailed nuclei were significantly higher in the exposed group. Unusually, long bridges were detected in 29% of BelAm patients with single-nodular goiters and 35% of those with multinodular goiters, while no such abnormalities were observed among patients from the Leningrad region. In the exposed subjects from BelAm, we also found positive correlations between their estimated dose of Iodine-131 from Chernobyl fallout and the frequency of tailed nuclei (p = 0.008) and bridges (p = 0.09). Further study is needed to confirm that these phenomena represent consequences of radiation exposure in the human organism.     

Cancer incidence in northern Sweden before and after the Chernobyl nuclear power plant accident

Sweden received about 5 % of the total release of ¹³⁷Cs from the Chernobyl nuclear power plant accident in 1986. The distribution of the fallout mainly affected northern Sweden, where some parts of the population could have received an estimated annual effective dose of 1–2 mSv per year. It is disputed whether an increased incidence of cancer can be detected in epidemiological studies after the Chernobyl nuclear power plant accident outside the former Union of Soviet Socialist Republics. In the present paper, a possible exposure–response pattern between deposition of ¹³⁷Cs and cancer incidence after the Chernobyl nuclear power plant accident was investigated in the nine northernmost counties of Sweden (2.2 million inhabitants in 1986). The activity of ¹³⁷Cs from the fallout maps at 1986 was used as a proxy for the received dose of ionizing radiation. Diagnoses of cancer (ICD-7 code 140-209) from 1980 to 2009 were received from the Swedish Cancer Registry (273,222 cases). Age-adjusted incidence rate ratios, stratified by gender, were calculated with Poisson regression in two closed cohorts of the population in the nine counties 1980 and 1986, respectively. The follow-up periods were 1980–1985 and 1986–2009, respectively. The average surface-weighted deposition of ¹³⁷Cs at three geographical levels; county (n = 9), municipality (n = 95) and parish level (n = 612) was applied for the two cohorts to study the pre- and the post-Chernobyl periods separately. To analyze time trends, the age-standardized total cancer incidence was calculated for the general Swedish population and the population in the nine counties. Joinpoint regression was used to compare the average annual percent change in the general population and the study population within each gender. No obvious exposure–response pattern was seen in the age-adjusted total cancer incidence rate ratios. A spurious association between fallout and cancer incidence was present, where areas with the lowest incidence of cancer before the accident coincidentally had the lowest fallout of ¹³⁷Cs. Increasing the geographical resolution of exposure from nine county averages to 612 parish averages resulted in a two to three times higher value of variance in the regression model. There was a secular trend with an increase in age-standardized incidence of cancer in both genders from 1980 to 2009, but significant only in females. This trend was stronger and statistically significant for both genders in the general Swedish population compared to the nine counties. In conclusion, using both high quality cancer registry data and high resolution exposure maps of ¹³⁷Cs deposition, it was not possible to distinguish an effect of ¹³⁷Cs on cancer incidence after the Chernobyl nuclear power plant accident in Sweden.     

Elevated frequencies of hypoxanthine phosphoribosyltransferase lymphocyte mutants are detected in Russian liquidators 6 to 10 years after exposure to radiation from the Chernobyl nuclear power plant accident

This study was conducted to determine whether the frequency of hypoxanthine phosphoribosyltransferase (HPRT) deficient lymphocyte mutants would detect an effect of radiation exposure in a population of Russians who were exposed to low levels of radiation while working in 1986 and 1987 as liquidators cleaning up after the Chernobyl nuclear power reactor accident. The HPRT lymphocyte cloning assay was performed on peripheral blood lymphocytes collected between 1992 and 1996 from 142 liquidators and 66 Russian controls, and between 1989 and 1993 from 231 American controls. Russian and American controls were not significantly different for either cloning efficiency or mutant frequency (MF); inclusion of both sets of controls in the analysis increased the ability to detect a Chernobyl exposure effect in the liquidators. After adjusting for age and smoking, the results revealed no significant difference in cloning efficiency of Chernobyl liquidators relative to Russian controls but a significant, 24% increase in liquidator HPRT mutant frequency over Russian controls (90% confidence interval was 7% to 45% increase). The analytical method also accounted for differences in precision of the individual estimates of log CE and log MF and accommodated for outliers. The increase in HPRT mutant frequency of liquidators is an attribute of the exposed population as a whole rather than of individuals. These results demonstrate that, under appropriate circumstances, the HPRT specific locus mutation assay of peripheral blood lymphocytes can be used to detect a semi-acute, low dose radiation exposure of a population, even 6 to 10 years after the exposure.     

Consequences and countermeasures in a nuclear power accident: chernobyl experience

Despite the tragic accidents in Fukushima and Chernobyl, the nuclear power industry will continue to contribute to the production of electric energy worldwide until there are efficient and sustainable alternative sources of energy. The Chernobyl nuclear accident, which occurred 26 years ago in the former Soviet Union, released an immense amount of radioactivity over vast territories of Belarus, Ukraine, and the Russian Federation, extending into northern Europe, and became the most severe accident in the history of the nuclear industry. This disaster was a result of numerous factors including inadequate nuclear power plant design, human errors, and violation of safety measures. The lessons learned from nuclear accidents will continue to strengthen the safety design of new reactor installations, but with more than 400 active nuclear power stations worldwide and 104 reactors in the Unites States, it is essential to reassess fundamental issues related to the Chernobyl experience as it continues to evolve. This article summarizes early and late events of the incident, the impact on thyroid health, and attempts to reduce agricultural radioactive contamination.     

Study on public acceptance of nuclear power plants: Evidence from China

Abstract

This empirical study evaluated the public acceptance of nuclear-power plants in China. A conceptual framework was proposed to explain the factors affecting nuclear-power acceptance based on antecedent variables, including social-media-use frequency, social-media information trust, nuclear-power knowledge, nuclear-accident knowledge, and risk-and-benefit perception. An empirical study was operated based on the Haiyang nuclear-power plant by conducting a face-to-face survey among residents who use social-media platforms near the plant. The frequency of social-media-use and the trust on social-media information promote individuals’ knowledge about nuclear power and nuclear accidents, leading to risk and benefit perception. Finally, benefit perception results in nuclear-power acceptance among the individuals. Implications and suggestions for future research are discussed.     

Content of free amino acids in blood plasma of the clean-up personnel at the Chernobyl nuclear power plant accident

In two groups of the persons participating in liquidation of the Chornobyl Power Plant Catastrophe (individuals which suffered from acute radiation sickness and those ones who were exposed to irradiation at doses 0.25-1.0 Gy) in a year after medical treatment the free amino acids, their derivatives, glucose, sodium lactate and pyruvate homeostasis changed in comparison with the control. The causes and possible mechanisms of these substances exchange regulation disorders in the key biochemical reactions ensuring the body organs and systems functioning were estimated. The experimental findings received can be used at planning the further examination and treatment-and-prophylactic measures for the persons which have been affected by ionizing radiation consequently the accident at the Chornobyl Nuclear Power Plant.     

Radiological assessment of protective countermeasures in the private sector of rural settlements in the Chernobyl nuclear power plant accident area

The effectiveness of countermeasures on private farms in rural settlements of the Russian Federation affected by the Chernobyl accident for the period of 1986-2005 was assessed. The averted collective doses to the residents of these settlements and the contribution of restrictive and agricultural countermeasures to dose reduction in the rural population have been estimated.     

Distribution of common carp in a Spanish reservoir in relation to thermal loading from a nuclear power plant

Arrocampo Reservoir is used as a cooling basin for a nuclear power plant located in southern Europe. Its annual mean temperature is about 30 °C with maxims that achieved 41.5 °C near the hot water effluent. Common carp (Cyprinus carpio, Linnaeus 1758) is the dominant pelagic fish species in this reservoir. Hydroacoustic surveys were conducted bimonthly over 9 years to characterize common carp abundance and distribution in the reservoir on an annual and seasonal temporal scale. Mean fish density during the period was 0.029 fish m⁻³, varying from a maximum of 0.038 in 2003 to a minimum of 0.012 in 1998. There were no significant differences in the mean fish density among years. Each year, fish distribution showed significant seasonal variation. Carp were homogeneously distributed during autumn and spring; in winter carp occupied warmer outfall areas, whereas in summer, fish were distributed in the coldest area of the reservoir (dam area) but avoided the warm outfall area. These seasonal tendencies of carp distribution was repeated every years. Behavioural reaction appears to be particularly important in explain carp distribution in this reservoir.     

Winter-spring sport fishery in the heated discharge of a nuclear power plant

A substantial winter-spring sport fishery has developed along the 1.83 km heated discharge canal of a nuclear power plant. An estimated 3166 fishermen caught an estimated 11 090 fish, representing 18 species, during a creel survey conducted from January through June, 1972. Eighty-seven per cent of the canal fishermen were successful in catching one or more fish, and averaged 2.07 fish per rod-hour of effort. Fishermen averaged 1.08 fish per rod-hour and had a 61 % success rate at other areas in the vicinity of the plant from April through November, 1965–1969. There was a correlation between the water temperature of the canal and the number of fish caught per rod-hour of effort.     

Long-term decline of brown algal assemblages from southern Brazil under the influence of a nuclear power plant

We investigated long-term trends in brown macroalgal assemblages inhabiting shallow subtidal rocky bottoms under the influence of thermal effluent discharge from the Brazilian nuclear power plant (BNPP). Three operational periods based on the units of the BNPP were analysed: T0 = pre-operational, between the years 1980 and 1983; T1 = operational period of unit 1, between 1988 and 1999; and T2 = operational period of units 1 and 2, between 2005 and 2012. Using generalized linear mixed models (GLMMs), we found significant declines in the numbers of genera and species over time. More than half of the species of brown macroalgae disappeared during T2. In addition, the numbers of macroalgal genera and species were inversely related to the local surface seawater temperatures. Multivariate analyses revealed a clear separation between the years of T2 and those of T0, indicating long-term changes in the community assemblages. Among the most common species in the area, the frequencies of Canistrocarpus cervicornis, Dictyopteris delicatula, Hincksia mitchelliae, Sargassum spp. and Sphacelaria tribuloides decreased during T2, while Padina gymnospora maintained rather high yearly frequencies during T2 (>40%). Our data suggest that seawater temperatures consistently higher than 30 °C together with peaks higher than 35 °C may have triggered the decline in the brown algae on rocky bottoms under the influence of the BNPP discharge. These results from southern Brazil are consistent with studies from other locations that ascribe changes in seaweed diversity to increasing seawater temperatures, highlighting the sensitivity of brown macroalgae to thermal stress and demonstrating their effectiveness as an ecological indicator for monitoring the effects of nuclear power plant effluents on coastal environments.     

Effects of thermal discharge from a nuclear power plant on culturable bacteria at a tropical coastal location in India

I.

Field studies were carried out 1 year to understand the distribution of culturable bacteria in the coastal waters in relation to the thermal discharge.     

Mortality risk in a historical cohort of nuclear power plant workers in Germany: results from a second follow-up

Possible health effects of low and protracted doses of ionizing radiation are relevant for persons who are exposed to an occupational context like nuclear industry workers. A historical cohort study was therefore conducted to examine mortality risks following occupational radiation exposure among 4,844 German nuclear power plant workers. This cohort included workers from ten nuclear power plants with an observational period from 1991 until 1997. The results of an enlarged cohort with 8,972 workers from all 17 nuclear power plants in West Germany are now available. During the extended follow-up period from 1991 to 2008, a total of 310 deaths among men were observed. The standardized mortality ratio (SMR) from all causes of deaths was estimated at 0.50 [95 % confidence interval (CI) 0.45–0.56]. A total of 126 deaths due to cancer occurred (SMR = 0.65; 95 % CI 0.51–0.82) and seven deaths due to leukemia (SMR = 1.23; 95 % CI 0.42–2.84). Overall, a reduced mortality compared to the general population of West Germany was observed indicating a healthy worker effect. In the dose–response analysis, no statistically significant risk due to ionizing radiation was seen. The hazard ratio (HR/mSv) for leukemia excluding chronic lymphocytic leukemia was estimated at 1.004 (95 % CI 0.997–1.011). In conclusion, the cohort is small and made up of young workers, most of whom were still employed at the end of the observational period in 2008. Results of the external analysis are difficult to interpret as influenced by a healthy worker effect. In the internal analysis, no excess of risk due to radiation was detected.     

Long-term monitoring of the coral reef fish communities around a nuclear power plant

Over the past 21 years (1979–1999) we have observed temporal changes in the fish communities on a coral reef around a nuclear power plant in southern Taiwan. Data used for analyses were collected bimonthly by scuba-diving ichthyologists at four sub-tidal stations (Stations A, B, D, E). The commercial operation of the nuclear power plant was launched in the summer of 1984. During the study period the number of fish species varies, with the coefficient of variation (CV) ranging from 19.0% (Station A) to 25.2% (Station D). Nevertheless, the sequential data on number of species follow a random trend in terms of runs up and down at all four stations. This characteristic persists both before and after the initiation of power plant operation. Dendrograms drawn using UPGMA (unweighted pair-group method using arithmetic averages) on the dissimilarity coefficients between yearly fish occurrences show that the years 1980–1984 are more closely grouped than any other years. This phenomenon prevails at all stations, indicating that wide-scale change occurred between 1984 and 1985. After the power plant began operation, changes in water temperature were minute at these sub-tidal stations. Impacts from other sources such as chlorine release and fish impingement seem remote. We believe temporal variations in the studied fish communities can be better explained as arising from natural fluctuations of environmental factors as well as physical disturbance caused by typhoons. The latter factor is also thought to account for the major faunal change between 1984 and 1985.     

A process for evaluating adverse environmental impacts by cooling-water system entrainment at a California power plant

A study to determine the effects of entrainment by the Diablo Canyon Power Plant (DCPP) was conducted between 1996 and 1999 as required under Section 316(b) of the Clean Water Act. The goal of this study was to present the U.S. Environmental Protection Agency (EPA) and Central Coast Regional Water Quality Control Board (CCRWQCB) with results that could be used to determine if any adverse environmental impacts (AEIs) were caused by the operation of the plant's cooling-water intake structure (CWIS). To this end we chose, under guidance of the CCRWQCB and their entrainment technical working group, a unique approach combining three different models for estimating power plant effects: fecundity hindcasting (FH), adult equivalent loss (AEL), and the empirical transport model (ETM). Comparisons of the results from these three approaches provided us a relative measure of confidence in our estimates of effects. A total of 14 target larval fish taxa were assessed as part of the DCPP 316(b). Example results are presented here for the kelp, gopher, and black-and-yellow (KGB) rockfish complex and clinid kelpfish. Estimates of larval entrainment losses for KGB rockfish were in close agreement (FH is approximately equals to 550 adult females per year, AEL is approximately equals to 1,000 adults [male and female] per year, and ETM = larval mortality as high as 5% which could be interpreted as ca. 2,600 1 kg adult fish). The similar results from the three models provided confidence in the estimated effects for this group. Due to lack of life history information needed to parameterize the FH and AEL models, effects on clinid kelpfish could only be assessed using the ETM model. Results from this model plus ancillary information about local populations of adult kelpfish suggest that the CWIS might be causing an AEI in the vicinity of DCPP.     

Chernobyl, the pathology of a nuclear accident

The accident at the Chernobyl nuclear power plant took place more than 20 years ago, on April 26th 1986, but its effects are still being felt, and its consequences influence the debate on nuclear power generation. The consequences for those working to contain the accident resembled those after the atomic bomb, 28 died from acute radiation sickness, and a further approximately 20 have died from the consequences of whole body radiation. The consequences for the millions exposed to high levels of fallout were quite different from those after the atomic bomb, and the talk will consider particularly the dramatic rise in thyroid carcinoma; currently estimated as about 4 000 cases. Fortunately only a small proportion has died from the disease. Initial studies concentrated on validating the diagnoses, later studies have shown a link between the molecular and morphologic pathology, the latent period and the aggressiveness of the tumours. These points will be reviewed, together with the link between radiation and thyroid carcinogenesis, and the possible future effects. The thyroid cancers are of particular significance because they represent the largest number of human tumours of one type due to one cause on one date that has ever occurred.     

Sleep complaints and polysomnographic findings: a study of nuclear power plant shift workers

The literature widely recognizes that shift workers have more health complaints than the general population. The objective of this study was to describe the prevalence of sleep complaints and verify the polysomnographic (PSG) variables of shift workers in two Brazilian nuclear power plants. We carried out a subjective evaluation with a sleep questionnaire. Based on these results, the interviewees that reported sleep-related complaints were referred for polysomnographic evaluation. Of the 327 volunteers initially evaluated by the sleep questionnaire, 113 (35%) reported sleep complaints; they were significantly older, had higher body mass index (BMI), and worked more years on shifts than those without sleep complaints. Of these 113, 90 met criteria for various sleep disorders: 30 (9%) showed obstructive sleep apnea (OSA), 18 (5.5%) showed limb movement, and 42 (13%) evidenced both sleep problems and had a significantly higher proportion of sleep stage 1 and arousals compared with the 23 shift workers that had no indices of sleep problems. The present study found that 90 (27.5%) of the evaluated participants met the PSG criteria of some type of clinical sleep disorder. This high proportion should be investigated for associations with other aspects of work, such as working hours, working schedule, years performing shift work, and access to health services. Due to the strong association between sleep disorders and the incidence of fatigue and sleepiness, the evaluation of the sleep patterns and complaints of shift workers is essential and should be considered to be one of the basic strategies of industry to prevent accidents.     

Cytogenetic damage in workers from a coal-fired power plant

The aim of this study was to investigate the genotoxic risk to workers occupationally exposed to coal combustion products in Afsin-Elbistan A power plant, located in south-eastern Turkey. We analysed chromosomal aberrations (CAs), polyploidy, sister-chromatid exchanges (SCEs), and micronuclei (MN) in 48 male workers without a history of smoking, tobacco chewing, or alcohol consumption. The results were compared with a control group of 30 healthy male individuals without exposure to any known genotoxic agents. The mean frequencies of CA, polyploidy, SCEs (P<0.01), and MN (P<0.05) were significantly higher in workers than in the control group, by the Mann-Whitney U-test. Spearman's rho correlation analysis revealed a significant increase in the frequency of CA and MN with increasing years of exposure (P<0.05). However, there was no significant effect of age on the cytogenetic markers analysed in both groups (P>0.05). The data obtained from this study clearly showed chromosomal hazard in the peripheral lymphocytes of workers exposed to coal combustion products in Afsin-Elbistan A power plant for several years. This cytogenetic damage might be attributed to the cumulative effects of several substances due to chemical complexity of the coal ash and gaseous emissions rather than a specific substance.