[en] It is important to carry out the post-irradiation tests on the actual fuel used for actual reactors and obtain the proving data to ensure the soundness and reliability of fuel and the pursue the safety of nuclear power generation. In 1974, the construction of a hot laboratory with large cells, in which such post-irradiation tests can be made, was planned, because at that time, there was none of such facility in Japan. As for the tests, after the inspection of appearance and the measurement of dimensions of fuel assemblies, they will be decomposed, and non-destructive and destructive tests will be carried out on fuel elements. About 20 fuel assemblies will be treated in one year, and fuel should be carried in after having been cooled for more than 100 days. This facility has been constructed in Japan Atomic Energy Research Institute, and is composed of the test laboratory and the administration building. In the test laboratory, βγ-cells and αγ-cells are arranged in L-form, and the operation room, measurement rooms, the service area, pool and hot laboratory are installed. 6 concrete cells and 3 lead cells are in the βγ-line, and 2 concrete cells and 2 lead cells are in the αγ-line. The appearance inspection equipments for fuel assemblies and fuel elements, the fuel assembly-decomposing equipment, the X-ray photographing equipment, the fuel element-measuring equipment, the image-analyzing equipment and so on have been installed. (Kako, I.)

[en] The fast experimental reactor ''Joyo'' reached the output of 75 MW on July 16, 1979, as the second step. The success of this first sodium-cooled reactor in Japan is the pride of those who have taken part in the research and development of sodium technology. The large scale sodium testing facility was constructed in the Oarai Technology Center, Power Reactor and Nuclear Fuel Development Corporation, and characteristic sodium testing facilities were constructed in universities, research institutes and related manufacturers. The mass transfer phenomenon through sodium, the tribology of materials in high temperature sodium, the flow of liquid sodium, the heat transfer characteristics of sodium, the vaporizing deposition of sodium through cover gas, the removal of impurities from sodium, the monitoring of sodium purity and the solubility of oxygen in sodium are the main subjects of the research and development. The radioactive corrosion products originated from a reactor core accumulates and the level of gamma radiation rises in low temperature part, therefore the countermeasures are studied and developed. The techniques to handle and treat sodium skillfully and safely must be established in fast reactors, and the cleaning of adhering sodium, the prevention of sodium fire and the fire-fighting technique are described. (Kako, I.)

[en] The development of plutonium fuel in Power Reactor and Nuclear Fuel Development Corp. was started in 1966 by the trial production of the mixed oxide fuel of plutonium and uranium. The design and production of the fuel for irradiation test, the development of the techniques handling plutonium, and the analysis of the behavior of irradiated fuel were carried out. Since 1972, the production of the core fuel for the fast experimental reactor ''Joyo'', and since 1975, the production of the MOX fuel for the advanced thermal reactor ''Fugen'' have been continued. In 1982, it is planned to start the construction of the facility to produce the core fuel for the fast prototype reactor ''Monju''. The outline of the development is described in this report. The MOX fuel charged in the MK-1 core of Joyo was 116 assemblies, and the operation was carried out from 1978 to 1981. The maximum linear output of about 280 W/cm and the maximum burnup of 40,500 MWd/t were attained. In Fugen, the fuel was designed so as to withstand the on-load refueling. The charging of MOX fuel in Fugen was 180 assemblies, including three times of replacement. The maximum linear output of about 420 W/cm, and the maximum burnup of 10,500 MWd/t were attained. The facilities for plutonium fuel and their management are described. (Kako, I.)

[en] Robot technology becomes more and more important in the field of atomic energy industries. Hitachi Ltd. has energetically engaged in the development of the robot technology for nuclear facilities, recognizing these situations. The course of the development of robot technology and the robots for nuclear facilities is described. As the practical examples of the robots for nuclear facilities, there have been automatic fuel exchangers, the remotely operated automatic exchangers for control rod driving mechanism, automatic and semi-automatic ultrasonic flaw detectors and so on. As the robots for nuclear facilities under development, control rod driving mechanism disassembling and cleaning system, the volume reduction device for spent fuel channel boxes and control rods and others are reported. (Kako, I.)

[en] For the quality control and quality assurance by radiation nondestructive test, X-ray or gamma-ray radiography has been used so far, but neutron radiography appeared on stage to meet the demand of modern age. Its largest merit is the usefulness in the internal inspection of composite materials and special single materials. At present, the research and practical use of neutron radiography centering around small nuclear reactors have advanced considerably in USA, but in Japan, the approach by accelerators seems to be necessary as well as the extention using nuclear reactors, considering the situation. In the Radiation Center of Osaka Prefecture, the research using a cyclotron accelerator was performed, and very good result close to that of reactor experiment was obtained. For the spread of neutron radiography, the development of photographic film method and image processing techniques is necessary. The approach using the van de Graaff accelerator in the RCOP and the result obtained by Kyoto University reactor, the test to put neutron radiography in practical use with a cyclotron accelerator, the on-line neutron radiography system and its application are reported. (Kako, I.)

[en] Inspection of safety countermeasures against earthquake in each stage between building plans and the operation of nuclear power plants was described from a regulative standpoint. The inspection procedure for conditions of location, construction plans, and the operation of nuclear power plants was figured. The items for inspection relating to earthquake-proof plans and the vibration by earthquake were also described. Last, basic ideas for earthquake-proof plans was stated. (Tsunoda, M.)

[en] The project of the direct steel making by utilizing high temperature reducing gas was completed in fiscal year 1980. By the research for eight years, the development of the technology required for the design, construction and operation of the pilot plant for direct steel making was accomplished successfully. The He-He intermediate heat exchanger was operated for more than 1960 hours at 1000 deg C. The steam reformer using He as the heat source was operated for about 3000 hours. The creep rupture test of various alloys at 1000 deg C was carried out for 30000 hours in the atmosphere and for 10000 hours in helium. Two excellent alloys, 113 MA and KSN, were selected by the property confirmation test, manufacturing test and workability test. At the start of the research, the following six subsystems were taken up, and the respective targets of research and development were decided. 1) Intermediate heat exchanger, 2) heat resistant super-alloys, 3) high temperature heat insulators, 4) reducing gas production equipment, 5) reduced iron production furnace, and 6) total system. The organization for the development, the budget and the results of development are reported. For the realization of the utilization of nuclear hear to industries, many problems to be clarified remain. (Kako, I.)

[en] The direct utilization of heat energy obtained from light water reactors has been recently planned, not only to utilize the energy to generate electric power. Although a few studies on the local small scale heat utilization were found so far, the forms and examples of large scale utilization are introduced in this paper. Since temperature is limited to be lower than the primary coolant temperature (about 320 deg C for PWRs and about 280 deg C for BWRs), the fields to require heat of comparatively low temperature such as paper and pulp industries, petrochemical industries, sea water desalting, or local heat supply will be the objects. In addition, the thermal discharge of condensers also should be utilized, but it is said to be difficult to pay economically. When steam is extracted from large scale power reactors, roughly two methods are applicable: one is to extract steam directly from main steam lines, and the other is to use steam after passing through back pressure turbines. Although both have a few slight problems, there is no problem that requires new large scale technical development. These seem not necessarily to pay economically as described before, but there is a trial calculation that they are competitive if the rise of fossil fuel costs is taken into account. Although they have little technical problem to be developed, future problems will lie in application software or the improvement of conditions for acceptance such as appropriate promotion and siting for heat utilization. (Wakatsuki, Y.)

[en] INIS is the system making the INIS Atomindex and carrying out the distribution of informations by the international cooperation of participating countries centering around the IAEA. In this report, the present state and future perspective of this system are explained. The INIS observed the tenth anniversary in 1980. The first issue was a small pamphlet of 24 pages publishing 147 papers which arrived before April 1, 1970. The organ in each country collects the literatures published in that country, thus the information file of high comprehensiveness and worldwide scale can be obtained. Also the burden of collecting and processing costs is shared corresponding to the quantity by large and small countries. Efforts have been exerted to put at same level and homogenize various countries by preparing manuals and holding seminars. As of October, 1980, 75 countries and organizations participate in the INIS, and 45 countries execute the input. The cumulative number reached 550,000 cases, and 75,000 cases were entered in 1979. The INIS was designed as the system utilizing computers. The flow of INIS works and the recent contents of INIS data base are shown. The introduction of data flagging, the expansion of the subject range to the medical application of ionizing radiation and radioisotopes, descriptors, thesauruses, INIS Atomindex, and the main subjects for the future development are described. (Kako, I.)

[en] The necessity of international cooperation in the treatment and disposal or management of radioactive wastes has been recognized more strongly recently, and the IAEA held the international congress in May, 1983. The safety techniques for this problem are likely to be resolved, but the public acceptance has become the factor hindering the development of nuclear power. It is important to advance international cooperation, aiming at the early establishment of the internationally common guide line to obtain the international consensus. In Japan, effort has been exerted to device to limit the quantity of waste formation, and the treatment of volume reduction and solidifying stabilization has been applied to the wastes formed. Thus, 490,000 drums of 200 l were stored in respective nuclear facilities as of September, 1983. The high level radioactive wastes from the reprocessing of spent fuel reached only 154 m³ and is stored in the reprocessing plant. The bilateral cooperation of Japan with USA, FRG, Australia and the People's Republic of China, and the multinaional cooperation in the NEA of OECD and IAEA regarding this problem are reported. Japan must exert efforts to obtain the understanding and cooperation of local society and international consensus to resolve the problem. (Kako, I.)