No abstract available

[en] On the decommissioning of Fukushima Dai-ichi nuclear power plant, fuel debris is packed to radioactive waste long-term storage containers. When the fuel debris includes water, since hydrogen (H2) and oxygen are produced by radiolysis of water, H2 concentration in the container increases. Passive Autocatalytic Recombiners (PARs) which is high performance on H2 treatment are developed to reduce the H2 concentration. The present study was conducted to confirm the effectiveness of H2 concentration reduction by the presently developed PARs. From the results, it was found that the current PAR can effectively reduce the H2 concentration. (author)

[en] The seventh regular inspection of No. 2 plant in the Fukushima No. 1 Nuclear Power Station was carried out from June 1 to November 7, 1984. The parallel operation was resumed on October 25, 1984, 147 days after the parallel off. The facilities as the object of inspection were the reactor proper, reactor cooling system, measurement and control system, fuel facilities, radiation control facilities, waste facilities, reactor containment installation and emergency power generation system. On these facilities of the object of inspection, the appearance, disassembling, leak, function, performance and other inspections were carried out, and as the result, abnormality was not found at all. The works related to this regular inspection were accomplished within the range of the allowable exposure dose based on the relevent laws. The main reconstruction works carried out during this regular inspection were the renewal of a fuel exchanger, the charging of new type 8 x 8 fuel assemblies, the removal of an exhaust compressor and the replacement of a part of offgas piping. (Kako, I.)

[en] Fukushima No. 2 Nuclear Power Station is under construction at present in Fukushima Prefecture by Tokyo Electric Power Co., Inc., and four BWRs of 1100 MW capacity each are installed. It is expected that No. 1 plant will start operation in May, 1982, and the last No. 4 plant in 1985. The construction of a harbor was planned to facilitate the transport of heavy things such as reactor pressure vessels and the water intake for condensers. The construction works were started in July, 1974, and almost completed in October, 1980. At the time of these works, consideration was given to the design and construction and the measures taken for the region, utilizing the experiences in the construction of Fukushima No. 1 Nuclear Power Station. The ships entering this harbor were assumed as 3000 t class freighters, and the depths of water-way and berths were decided as 6 m and 6.5 m, respectively. The position and direction of the entrance and the plane figure and crown height of breakwaters are explained. The topography and geological features of the site, waves, the construction works of breakwaters, unloading wharf, water intake and open channel, and the production of aggregate and concrete are described. The unloading wharf is 150 m long, and a 900 t gin pole crane and a 150 t derrick crane are installed. (Kako, I.)

[en] Published in summary form only

[en] The best estimate method of safety analysis involves choosing a realistic set of input parameters for a proposed safety case and evaluating the uncertainty in the results. Determining the uncertainty in code outputs remains a challenge and is the subject of a benchmarking exercise proposed by the Organization for Economic Cooperation and Development. The work proposed in this paper will contribute to this benchmark by assessing the uncertainty in a depletion calculation of the final nuclide concentrations for an experiment performed in the Fukushima-2 reactor. This will be done using lattice transport code DRAGON and a tool known as DINOSAUR. (author)

[en] Post Fukushima incident, various concerns were raised by public and media about the safety of nuclear installations operating all around the world. All nuclear related eventualities of the past were meshed with the present, by adding disproportionate factors, resulting in unrealistic conclusions based mostly on notions. A dynamic and well thought Indian nuclear energy programme was no exception to it. Fear of unknown radiation syndrome played up on the minds of common man. The sequence of events that took place at Fukushima nuclear power plants were result of unexpected catastrophe to which sustenance of any industry (including nuclear power plants) could not be guaranteed. The world has seen the dooms day in Japan, in form of flying of ships and drifting of aircrafts in a literal sense. Well studied foundations and bridges came down like a falling stone. So were affected, the six nuclear power plants. But proving up to the soundproof design basis, the damages were contained and the consequences were brought to manageable limits. Not even a single casualty occurred as a result of radiations at Fukushima. However sporadic data observations and short term conclusions by few agencies and media kindled grave concerns in the minds of people all over the world. Ongoing protests at Jaitapur, mainly on issues like rehabilitation and land acquisition flared up due radiation syndrome at the backdrop of Fukushima incident. This paper discusses various concerns expressed after Fukushima incident, overview on proposed Jaitapur nuclear power plant and justifications to the raised notions. (author)

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