News and Views: Perspectives for Nuclear Energy in Brazil After Fukushima

More than two decades after the Chernobyl accident, the world was experiencing a nuclear renaissance when an earthquake followed by a tsunami, both of uncommon proportions, led to major releases of radiation at the Fukushima Dai-ichi nuclear central. Many countries are now reevaluating decisions to expand their nuclear parks, a change of course motivated by a number of considerations. Combined with the same premises, lessons learned from the history of its nuclear program compel Brazil to turn to the renewable sources of energy at its disposal.     

Continuously improving safety of nuclear installations: An approach to be reinforced after the Fukushima accident

After the Three Mile Island accident in 1979 and the Chernobyl accident in 1986, the Fukushima accident shows that the probability of a core meltdown accident in an LWR (Light Water Reactor) has been largely underestimated. The consequences of such an accident are unacceptable: except in the case of TMI2 (Three Mile Island 2) large areas around the damaged plants are contaminated for decades and populations have to be relocated for long periods. This article presents the French approach which consists in improving continuously the safety of the Nuclear Power Plants (NPP) on the basis of lessons learned from operating experience and from the progress in R&D (Research and Development). It details the key role played by IRSN (Institut de radioprotection et de sûreté nucléaire), the French TSO (Technical and scientific Safety Organization), and shows how the Fukushima accident contributes to this approach in improving NPP robustness. It concludes on the necessity to keep on networking TSOs, to share knowledge as well as R&D resources, with the ultimate goal of enhancing and harmonizing nuclear safety worldwide.     

Estimation of the total population moving into and out of the 20 km evacuation zone during the Fukushima NPP accident as calculated using “Auto-GPS” mobile phone data

The first objective data showing the geographical locations of people in Fukushima after the Fukushima Dai-ichi nuclear power plant accident, obtained by an analysis of GPS (Global Positioning System)-enabled mobile phone logs, are presented. The method of estimation is explained, and the flow of people into and out of the 20 km evacuation zone during the accident is visualized.     

Radioecological measurement in Leningrad oblast

The results from studies of cesium isotopes in the soils of the Leningrad region conducted after the accidents at the Chernobyl and the Fukushima are presented.     

Accident at the Fukushima Dai-ichi Nuclear Power Stations of TEPCO —Outline & lessons learned—

The severe accident that broke out at Fukushima Dai-ichi nuclear power stations on March 11, 2011, caused seemingly infinite damage to the daily life of residents. Serious and wide-spread contamination of the environment occurred due to radioactive materials discharged from nuclear power stations (NPSs). At the same time, many issues were highlighted concerning countermeasures to severe nuclear accidents. The accident is outlined, and lessons learned are extracted with respect to the safety of NPSs, as well as radiation protection of residents under the emergency involving the accident. The materials of the current paper are those released by governmental agencies, academic societies, interim reports of committees under the government, and others.     

Application of SSNTDs to investigations of radiation accident after-effects

Track methods and devices used for studies conducted after radiation accidents are considered. Solid State Nuclear Track Detectors (SSNTDs) are applied for measurements of contamination in soil, water, biological and other objects of alpha-emitting radionuclides, as well as for estimation of neutron doses by means accident dosimeters. Known radiation accidents (Chernobyl a.o.) and potential emergencies (sunken submarine “Komsomolets”, nuclear reactors) are discussed. Some result of SSNTD application at after-accident period are presented.     

Radioluminescent dosimetry of α-quartz

The variation in the ultraviolet component of the radioluminescence intensity during X-ray excitation of α-quartz has been found to be dependent on the dose of previous ionizing irradiation. A new method of radiation dosimetry using UV radioluminescence is described. Radioluminescent dosimetry measurements of γ-rays produced by Chernobyl accident and background irradiation were made using natural and extracted crystalline quartz.     

Investigation of spatial distribution of <Superscript>137</Superscript>Cs in soil in area of location of the Armenian NPP

Problem of evaluation of spatial distribution of ¹³⁷Cs in soil and of direct radiation impact of the Armenian NPP on population dwelling in the region of its location, on the background of global radioactive fallouts and aftermaths of the Chernobyl accident is solved. Content of radiationdangerous radionuclide ¹³⁷Cs in soil on the territory with radius 50 km including the NPP area has been investigated. Points of monitoring have been chosen on the basis of analysis of meteorological data and calculation of the distance where emissions from NPP have maximal concentration in air. The obtained results agree well with the data of UN Scientific Committee of Radiation Action.     

Internal radiocesium contamination of adults and children in Fukushima 7 to 20 months after the Fukushima NPP accident as measured by extensive whole-body-counter surveys

The Fukushima Dai-ichi NPP accident contaminated the soil of densely-populated regions in Fukushima Prefecture with radioactive cesium, which poses significant risks of internal and external exposure to the residents. If we apply the knowledge of post-Chernobyl accident studies, internal exposures in excess of a few mSv/y would be expected to be frequent in Fukushima.Extensive whole-body-counter surveys (n = 32,811) carried out at the Hirata Central Hospital between October, 2011 and November, 2012, however show that the internal exposure levels of residents are much lower than estimated. In particular, the first sampling-bias-free assessment of the internal exposure of children in the town of Miharu, Fukushima, shows that the ¹³⁷Cs body burdens of all children (n = 1,383, ages 6–15, covering 95% of children enrolled in town-operated schools) were below the detection limit of 300 Bq/body in the fall of 2012. These results are not conclusive for the prefecture as a whole, but are consistent with results obtained from other municipalities in the prefecture, and with prefectural data.     

从“福岛第一核电站事故”看我国核能利用的核安全

文章简要说明了福岛第一核电站事故的起因、发展和后果,并对核电站全厂断电、反应堆压力容器及安全壳超压、氢爆等导致事故恶化的原因作了分析.文章还就导致福岛核事故的相关因素与我国核电站的安全设计及防范对策进行了分析比较.在吸取福岛核事故的经验教训方面,文章提出了若干值得引发关注的启示,作为我国在建和在役核电站的改进,以及新设计核电站的参考.文章还就我国能源的状况,核能发展的必要性,以及核能发展的方针进行了探讨.     

Radiation Measurement of some Materials in Egypt after Chernobyl Accident

The publication shows the radiological measurements of rain water, cress, and milk before and after Chernobyl nuclear power accident. The measurements showed that Egyptian environment was affected by the accident, but the increase of radioactive contamination was small and below the permissible. The paper suggests methodological procedures for measuring the growth activity in the studied materials. It offers also a simplified diagram for automatic national radiological monitoring station to measure the environmental background radiation by a routine way for detection any increase of radioactivity rapidly. This station enables the responsibles to take rapid and optimum decisions in time to lessen the environmental radiological contamination.     

90Sr Content in Some Bottom Lake Samples

Abstract

Bottom sediments of two lakes in Bulgaria (Lake Iskar, Lake Pantcharevo) are investigated concerning the ⁹⁰Sr-content. The interpretation of the data shows that this region has been more affected by the Chernobyl accident than comparable soils in Japan.     

Initial activities of a radiation emergency medical assistance team to Fukushima from Nagasaki

As an urgent response to serious radiological accidents in the Fukushima Daiichi nuclear power plant, the radiation emergency medical assistance team (REMAT) from Nagasaki University landed at Fukushima on March 14, 2011, two days after the initiation of radiation crisis by the hydrogen explosion at Unit-1 reactor. During a succession of unexpected disasters, REMAT members were involved in various activities for six days, such as setting the base for radiological triage at the Fukushima Medical University, considerations for administration of stable iodine, and risk communication with health care workers. This report briefly describes what happened around REMAT members and radiation doses measured during their activities.     

Third generation nuclear plants

After the Chernobyl accident, a new generation of Light Water Reactors has been designed and is being built. Third generation nuclear plants are equipped with dedicated systems to insure that if the worst accident were to occur, i.e. total core meltdown, no matter how low the probability of such occurrence, radioactive releases in the environment would be minimal. This article describes the EPR, representative of this “Generation III” and a few of its competitors on the world market.     

Electron spin resonance (ESR) dating and ESR applications in quaternary science and archaeometry

The scope of application of ESR spectroscopy has greatly expanded with the advent of its widespread use in radiation exposure dating around 1980 and its use in retrospective dosimetry since the Chernobyl disaster in 1986. Few fields of study are of such breadth that they span topics as diverse as dating of human origins, volcanic activity, cave deposits and earthquakes, while also providing prognoses for radiation accident victims. Between 1945 and 1975 ESR was mainly used to define the nature of paramagnetic defects in crystalline and amorphous materials, which laid the foundation for its use in applied areas in Quaternary geology, archaeometry and accident dosimetry. This review chronicles the development of the use of ESR in applied science since 1975, with particular emphasis on the state of the art in the period 1987–1997. The first part of the review focuses mainly on the range of applications for datable materials: tooth enamel (Section 2), calcite (Section 3) and quartz (Sections 4–9), while the second part comprises the areas of retrospective dosimetry (Section 10) and new applications (Section 11). The review concludes (Appendix A) with an introduction to the physical basis and assumptions involved in ESR dating, and compilations of valuable reference works for students and workers in this field.     

Cesium, americium and plutonium isotopes in ground level air of vilnius

Systematic observations of radionuclide composition and concentration in the atmosphere have been carried out at the Institute of Physics in Vilnius since 1963. Increases in activity concentration of radionuclides in the atmosphere were observed after nuclear weapon tests and the Chernobyl NPP accident. At present the radiation situation in Lithuania is determined by two main sources of radionuclides, forest fire and resuspension products transferred from highly polluted region of the Ukraine and Belarus. The activity concentrations of ¹³⁷Cs were measured in two to three days samples while plutonium and americium in monthly samples. The extremely high activity concentrations of ²³⁸Pu, ^239,240Pu, ²⁴¹Am determined in the atmosphere during the Chernobyl accident can be explained by transport of “hot particles” of different composition. Activity concentration in 1995–2003 of ²⁴¹Am and ^239,240Pu isotopes ranged from 0.3 to 500 and from 1 to 500 nBq/m³, respectively. ²³⁸Pu/^239,240Pu activity ratio in measured samples differs from 0.03 to 0.45. A decrease in ²⁴⁰Pu/²³⁹Pu atomic ratio from 0.30 to 0.19 was observed in 1995–2003.     

Cesium,americium and plutonium isotopes in ground level air of Vilnius

Systematic observations of radionuclide composition and concentration in the atmosphere have been carried out at the Institute of Physics in Vilnius since 1963. Increases in activity concentration of radionuclides in the atmosphere were observed after nuclear weapon tests and the Chernobyl NPP accident. At present the radiation situation in Lithuania is determined by two main sources of radionuclides, forest fire and resuspension products transferred from highly polluted region of the Ukraine and Belarus. The activity concentrations of ¹³⁷Cs were measured in two to three days samples while plutonium and americium in monthly samples. The extremely high activity concentrations of ²³⁸Pu, ^239,240Pu, ²⁴¹Am determined in the atmosphere during the Chernobyl accident can be explained by transport of “hot particles” of different composition. Activity concentration in 1995–2003 of ²⁴¹Am and ^239,240Pu isotopes ranged from 0.3 to 500 and from 1 to 500 nBq/m³, respectively. ²³⁸Pu/^239,240Pu activity ratio in measured samples differs from 0.03 to 0.45. A decrease in ²⁴⁰Pu/²³⁹Pu atomic ratio from 0.30 to 0.19 was observed in 1995–2003.     

(137)Cs and (40)K activity concentration measurements and elemental analysis in lichen samples collected from the Giresun province of northeastern Turkey

About 21 years after the Chernobyl accident, (137)Cs and (40)K activity concentration measurements using gamma-ray spectroscopy and elemental analysis using energy dispersive X-ray spectroscopy were performed in five different lichen species collected from the Giresun province of northeastern Turkey. Being a symbiosis of algae and fungi, lichens are mostly used for environmental measurements since the fungal partner is responsible for the uptake of necessary nutrients or harmful substances, such as heavy metals of radionuclides. The gamma activity results showed that (137)Cs, an artificial radionuclide released from the Chernobyl power plant accident, is still eminent in the environment of the province. The mean activity concentrations of (137)Cs and (40)K ranged from 24 to 254 with the mean value of 102 Bq kg(-1) and from 345 to 2103 with the mean value of 1143 Bq kg(-1) in dry weight. The results of the elemental analyses showed potassium, calcium, titanium, iron, tin, and barium in different concentrations.     

Mössbauer Study of Iron-Containing Atmospheric Aerosol Collected During the Chernobyl Accident

During the Chernobyl accident a large quantity of radionuclides was released into the troposphere and contaminated a wide geographical area. The present study concentrates on atmospheric iron. The Mössbauer measurements were performed on the atmospheric aerosol collected during the accident on 27–30 April 1986 in Warsaw and in Legnica, Poland. Results were compared with the data obtained for samples collected at the same sites just before the accident. The observed increase in iron concentration determined by Mössbauer effect could be explained by the enrichment of natural iron in ⁵⁷Fe isotope in ⁵⁶Fe(n,)⁵⁷Fe reaction.     

Fluorescent Study of Human Blood Plasma Albumin Alterations Induced by Ionizing Radiation

The use of hydrophobic fluorescent probe ABM (benzanthrone derivative) and albumin autofluorescence allowed show conformational alterations in Chernobyl clean-up workers blood plasma. Results obtained in 1996–1997 suggest that acidic expansion of plasma albumin takes place. Latest data (2006–2008) result in splitting of albumin alterations onto two stages - acidic expansion and N-F transition. The N-F transition is accompanied by the blue shift of fluorescence spectra and dehydration of tryptophanyl region of albumin molecule. In 2007 obtained.patterns of ABM spectra had never been previously seen in examined healthy individuals or patients with tuberculosis, multiple sclerosis, rheumatoid arthritis, etc. Patterns of ABM fluorescence spectra are associated with conformational changes of blood plasma albumin. The use of probe ABM and albumin auto-fluorescence allowed show conformational alterations in albumin of Chernobyl clean-up workers blood plasma. It is necessary to note that all investigated parameters significantly differ in observed groups of patients. These findings reinforce our understanding that the blood plasma albumin is a significant biological target of radiation. It may be concluded that fluorescence characteristics are representative of radiation induced albumin alterations and its carrier function.