Search

This article argues that the history of nuclear energy can and should be analyzed as a history of water. Taking inspiration from David Edgerton's The Shock of the Old and recent efforts to merge the history of technology with environmental history, here the focus shifts from nuclear reactors to the "conventional" parts of nuclear power plants. This brings to the fore that a range of hydraulic technologies with long prehistories-pumps, pipes, valves, dams, dikes, and so on-have been crucially important for nuclear safety. The "atomic age" is fundamentally a hydraulic age and should be seen in relation to experiences gathered by past hydraulic civilizations.

A solution for the nuclear waste problem is the key challenge for an extensive use of nuclear reactors as a major carbon free, sustainable, and applied highly reliable energy source. Partitioning and Transmutation (P&T) promises a solution for improved waste management. Current strategies rely on systems designed in the 60's for the massive production of plutonium. We propose an innovative strategic development plan based on invention and innovation described with the concept of developments in s-curves identifying the current boundary conditions, and the evolvable objectives. This leads to the ultimate, universal vision for energy production characterized by minimal use of resources and production of waste, while being economically affordable and safe, secure and reliable in operation. This vision is transformed into a mission for a disruptive development of the future nuclear energy system operated by burning of existing spent nuclear fuel (SNF) without prior reprocessing. This highly innovative approach fulfils the sustainability goals and creates new options for P&T. A proof on the feasibility from neutronic point of view is given demonstrating sufficient breeding of fissile material from the inserted SNF. The system does neither require new resources nor produce additional waste, thus it provides a highly sustainable option for a future nuclear system fulfilling the requests of P&T as side effect. In addition, this nuclear system provides enhanced resistance against misuse of Pu and a significantly reduced fuel cycle. However, the new system requires a demand driven rethinking of the separation process to be efficient.

The most important contributions of radiation chemistry to some selected technological issues related to water-cooled reactors, reprocessing of spent nuclear fuel and high-level radioactive wastes, and fuel evolution during final radioactive waste disposal are highlighted. Chemical reactions occurring at the operating temperatures and pressures of reactors and involving primary transients and stable products from water radiolysis are presented and discussed in terms of the kinetic parameters and radiation chemical yields. The knowledge of these parameters is essential since they serve as input data to the models of water radiolysis in the primary loop of light water reactors and super critical water reactors. Selected features of water radiolysis in heterogeneous systems, such as aqueous nanoparticle suspensions and slurries, ceramic oxides surfaces, nanoporous, and cement-based materials, are discussed. They are of particular concern in the primary cooling loops in nuclear reactors and long-term storage of nuclear waste in geological repositories. This also includes radiation-induced processes related to corrosion of cladding materials and copper-coated iron canisters, dissolution of spent nuclear fuel, and changes of bentonite clays properties. Radiation-induced processes affecting stability of solvents and solvent extraction ligands as well oxidation states of actinide metal ions during recycling of the spent nuclear fuel are also briefly summarized.

High-temperature gas-cooled reactors (HTGRs) are advanced nuclear systems that will receive heavy use in the future. It is important to develop spent nuclear fuel reprocessing technologies for HTGR. A new method for recovering uranium from tristructural-isotropic (TRISO-) coated fuel particles with supercritical CO(2) containing tri-n-butyl phosphate (TBP) as a complexing agent was investigated. TRISO-coated fuel particles from HTGR fuel elements were first crushed to expose UO(2) pellet fuel kernels. The crushed TRISO-coated fuel particles were then treated under O(2) stream at 750°C, resulting in a mixture of U(3)O(8) powder and SiC shells. The conversion of U(3)O(8) into solid uranyl nitrate by its reaction with liquid N(2)O(4) in the presence of a small amount of water was carried out. Complete conversion was achieved after 60 min of reaction at 80°C, whereas the SiC shells were not converted by N(2)O(4). Uranyl nitrate in the converted mixture was extracted with supercritical CO(2) containing TBP. The cumulative extraction efficiency was above 98% after 20 min of online extraction at 50°C and 25 MPa, whereas the SiC shells were not extracted by TBP. The results suggest an attractive strategy for reprocessing spent nuclear fuel from HTGR to minimize the generation of secondary radioactive waste., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The review of the environmental projects of the International Atomic Energy Agency is presented. Basic IAEA documents intended to protect humans and the Environment are considered and their main features are discussed. Some challenging issues in the area of protection of the Environment and man, including the impact of nuclear facilities on the environment, radioactive waste management, and remediation of the areas affected by radiological accidents, nuclear testing and sites of nuclear facilities are also discussed. The need to maintain the existing knowledge in radioecology and protection of the environment is emphasised.

The Fort St. Vrain Nuclear Generating Station was a one-of-its-kind High Temperature Gas Cooled Reactor located near Denver, CO. Due to operational difficulties, the reactor was permanently shut down in August 1989. Plants to ship the spent reactor fuel to Idaho were thwarted by the Governor of Idaho. The inability to ship the spent reactor fuel offsite necessitated the construction of an Independent Spent Fuel Storage Installation (ISFSI) in order to proceed with the decommissioning of the reactor. After loading the ISFSI, decommissioning of the reactor was initiated and successfully completed. At the same time, the site was repowered using natural gas. As part of a settlement with the owner of the reactor, the U.S. Department of Energy agreed to take title to the spent fuel in the ISFSI and obtain an NRC license for the facility. The license for the ISFSI was transferred to the DOE in June 1999. Day-to-day operations of the ISFSI are accomplished by the DOE's Maintenance and Operations contractor, Bechtel Babcock Wilcox Idaho (BBWI). BBWI also operates the Three Mile Island Unit 2 ISFSI in Idaho for the DOE. This paradigm for ISFSI operations has been highly successful and is expandable to additional ISFSIs that may come under the jurisdiction of the DOE.

A study of dosimetric errors is under way within an international collaborative study of cancer risk among workers in the nuclear industry. The objective is to quantify errors in the estimated photon doses to individual organs used for cancer risk estimation. One source of errors is the response of old dosemeters in workplace exposure conditions. As these conditions are not well known, the International Study must rely on expert estimations. This paper describes a method to assess the proportion of the dose from photons in three energy ranges (< 100, 100-300, > or = 300 keV) using the responses under filters of a multi-element dosemeter. The method was tested on experimental and simulated data and provides a good estimate of the proportion of dose from photons below 100 keV, the most critical for dosemeter response. It was applied to personnel readings in one facility, confirming the experts' estimation. Beyond the International Study, the method has implication for the monitoring and protection of workers.

There is a large discrepancy between potential needs for nuclear propulsion and power systems for the human exploration of Mars and the current status of R&D funding, public opinion, and governmental support for these technologies. Mission planners and spacecraft designers, energized by the recent claims of possible discovery of life on Mars and responding to increased public interest in the human exploration of Mars, frequently propose nuclear reactors and radioisotope thermoelectric generators (RTGs) for interplanetary spacecraft propulsion and for power supply on the surface of Mars. These plans and designs typically assume that reactors will be available "on-the-shelf," and do not take the extensive R&D costs required to develop such reactors into consideration. However, it is likely that current U.S. policies, if unchanged, will prohibit the launch of nuclear reactors and large RTGs in response to a perceived risk by the public.

Radiation doses from natural radiation and from man-made modifications on natural radiation, and different natural radiological environments in the Nodic countries are summarized and used as a perspective for the radiological consequences of nuclear energy production. The significance of different radiation sources can be judged against the total collective effective dose equivalent from natural radiation in the Nordic countries, 92,000 manSv per year. The collective dose from nuclear energy production during normal operation is estimated to 20 manSv per year and from non-nuclear energy production to 80 manSv per year. The increase in collective dose due to the conservation of heating energy in Nordic dwellings is estimated to 23,000 manSv per year, from 1973 to 1984. An indirect radiological danger index is defined in order to be able to compare the significance of estimated future releases of radionuclides from a final repository of spent nuclear fuel to the consequences of natural radionuclides in different environments. The danger index of natural radiological environments will not be significantly increased by future releases of nuclear fuel radionuclides.

Estimates are presented on the carbon-14 generation rates in several reactor types and in peaceful nuclear explosions. If the carbon-14 generated in light water reactors is released, the population radiation dose rate it causes initially will be comparable to that resulting from the krypton-85 and tritium generated in these reactors. Because of the long half-life, the radiation dose commitment and the dose rate resulting from the environmental build-up of carbon-14 are considerably larger than those of the two other radionuclides.

The energies of recoil particles from (n, alpha) or (n, 2 alpha) reactions of Li and B were investigated by solid state detector and gas phase electrodeposition as previously reported on 228Th series. Nuclear reactor of UTR-Kinki was used as thermal neutron source. Particles from 6Li (n, alpha) 3T and 10B (n, alpha) 7Li were collected on a sheet of triacetate film by gas phase electrodeposition at atmospheric pressure. The film was etched with 6M-NaOH at 50 degrees C. The tracks thus obtained were taken as photographs with a microscope (X600). By counting the number of tracks on the film at various etching times, the energies of alpha-particles were evaluated according to the calibration curve of 227Ac series. Among various peaks of tract density, the two peaks having the evaluated values of 1.85 MeV for 6Li and 1.48 MeV for 10B agreed approximately with the theoretical values of 2.05 MeV and 1.47 MeV of alpha-particle energies for respective reactions.

The present study examined the relationship between biochemical, psychologic, and behavioral components of chronic stress associated with living near the damaged nuclear power plant at Three Mile Island (TMI). Relative to control subjects, TMI subjects had higher levels of urinary cortisol, which correlated significantly with urinary catecholamines, self-report of physical and mental symptoms, and decrements in task performance. Further, it was found that males had higher urinary cortisol levels than females at TMI, while at the control sites, levels of cortisol were comparable between males and females. Finally, no significant relationship between coping style and urinary cortisol was detected. Levels of stress response among TMI are residents, though significantly greater than control subjects, were within normal ranges and thus should be considered subclinical in intensity. Their persistence over 17 months, however, suggests some cause for concern.

The paper discusses measures to be taken during hypothetic utmost breakdown at nuclear power stations when the amount of radioactive nuclides injected in the atmosphere exceeds the permissible level. Three consecutive steps of the breakdown are distinguished and, correspondingly, medical and hygienic measures are developed to provide radioprotection of the personnel, population, and workers involved in the elimination of the consequences of the breakdown. Criteria are given for developing protective measures and implementing thereof.

The absorbed dose of low LET radiation that would be lethal (due to bone marrow failure) to 50% of an exposed human population is a matter for concern in planning for the consequences of an accident to a nuclear reactor and in the event of nuclear war. Since accidents with radiation-generating equipment or in the nuclear fuel processing industry might provide relevant human data, published accounts of these are reviewed. Two accidents, one in the USA, the other in Yugoslavia, both involving exposure to neutrons as well as gamma-rays, are identified as possibly satisfying the criteria of uniformity of dose, magnitude of dose and dose rate necessary to provide useful information on the value of LD50/60 for man. The symptomatology of the exposed individuals is discussed in terms of the published doses. Detailed examination of the dosimetry for these two accidents revealed possible ambiguities and a thorough re-examination has been carried out, the results of which are reported in detail in the Appendix. This indicates considerable and largely unresolvable uncertainty in the magnitude of the dose to exposed individuals when expressed as the low LET equivalent dose in bone marrow. It is also shown that the relationship between severity of effects and dose to exposed individuals is not the same for both accidents and it is argued that the experience from the Yugoslavian accident is more relevant to the determination of the sensitivity to radiation of an exposed human population. Given the uncertain nature of the accident data and the small amount of other relevant human data at present available, the uncertainty of current knowledge of man's sensitivity to the acute effects of exposure to ionising radiation is discussed.

The causes and progress of the accident at Chernobyl are described, and a comparison between the Chernobyl accident and the 1979 accident at the Three Mile Island nuclear power station is made. Significant similarities between Chernobyl and Three Mile Island include complacency of operators and industry, deliberate negation of safety systems, and a lack of understanding of their plant on the part of the operators, which shows the critical importance of the human element. The Chernobyl accident has implications for nuclear power in the United States; it will affect the research program of the Nuclear Regulatory Commission, regulation of Department of Energy reactors, new reactor designs, and public attitudes.