[en] The PNC high power CW (Continuous Wave) electron accelerator has been pre-commissioned with the injector and the first accelerating tube. We have been very successful to produce 1 ms pulse width electron beam with 50 mA peak and energy about 3.5 MeV at present. The pre-commissioning shows important results that the accelerator with TWRR (Traveling Wave Resonant Ring) under 100 mA beam loading is easily handled and verified the acceleration of long pulse beam of 1 ms. PNC linac is the 10 MeV, 20 mA (average current, 20% duty) accelerator with eight normal conducting TWRR disk loaded accelerating tubes to study feasibility of nuclear waste transmutation. After pre-commissioning, the rest of six accelerating TWRR tubes will be installed by March 1997. Commissioning of the entire 10 MeV linac will begin at Spring 1997. 9 refs., 1 fig., 1 tab

[en] Hand tools, such as a sledgehammer, are widely used in refurbishment activities; nonetheless, there is very little knowledge on nanoparticle generation. We measured particle number size distributions (PSDs) and concentrations (PNCs) in the 10–420 nm using a NanoScan scanning mobility particle sizer (SMPS) during the use of hand tools (i.e., sanding and removal of wall) in a real indoor refurbishment environment. Results indicated that refurbishment activities from removal of wall increased average PNCs by ~ 6 times over the background while it was ~ 1.5 times higher than sanding. The highest total PNC was 1.9 × 10⁵ particles cm⁻³ that corresponded to removal of wall activities. For sanding activities, PNC was lower as the coat of the plaster was probably slightly wet. Moreover, comparison between the two principal activities showed a similar peak in the accumulation mode (~ 65 nm), with a monomodal pattern. Results suggest that removal of wall activities emitted nanoparticles with a 59% of contribution in the Aitken mode. According to these data, it can be inferred that the application of hand tools in refurbishment activities generates lower total PNC than using electromechanical equipment. This study may contribute to our understanding of nanoparticle generation in refurbishment activities. .

[en] The Power Reactor and Nuclear Fuel Development Corporation (PNC) designed an Advanced Containment and Surveillance System (A C/S) for its Plutonium Fuel Production facility at Tokai-Mura, Japan. PNC entered into an agreement with the US Department of Energy (DOE) to have Sandia National Laboratories (SNL) develop options for authenticating the information provided by the A C/S System, as well as to develop PNC-selected hardware for demonstration purposes. The equipment was installed in the early summer of 1989, and has undergone performance evaluation since that time. The key technologies being evaluated include authentication item monitoring, video and digital signal authentication, and event data logging, plus the system integration of these components. A review of the performance of this equipment will be highlighted. 3 refs., 4 figs

[en] The accumulated amount of MOX fuel fabricated at PNC is about 100 ton MOX. The number of irradiated fuel rods is about 40,000. None of the fuel rods irradiated in JOYO and FUGEN has failed until now. This indicates that our design, fabrication, quality control and other technologies are reliable. The achievements of the development of the MOX fuel fabrication technology are concentrated in PFPF, in which remote controlled and automated operation systems are fully adopted. The technology related to MOX fuel fabrication has basically been established in Japan. Moreover, PNC will continue at advancements and improvements of the MOX fuel fabrication technology, which are required to achieve the commercialization

[en] The plant has started radioactive waste incineration in October 1989, and since then, more than 30 tons of solid waste have been incinerated without trouble. This short report summarizes the plant concept and construction and operational experience of the plant. In the coming near future, we will install fully automated waste charging system to reduce the number of required operator for waste charging

No abstract available

[en] This is the report by the Atomic Energy Commission to the Director of Science and Technology Agency, and the report by the Committee on Examination of Nuclear Fuel Safety to the Atomic Energy Commission of Japan concerning the subject matter is attached. The alteration of the use of fuel in the Laboratory is to produce the fuel for the irradiation core in the experimental fast reactor differing from the conventional one in dimensions, chemical composition, and Pu isotope composition, thereby entailing the alterations of the production facility. The safety of the altered facility including those for pellet production and fuel fabrication is well confirmed. (Mori, K.)

[en] The principal items of the nuclear budget for the fiscal year 1979 are 165,700 Million for the Science and Technology Agency for the promotion of nuclear energy development, and for the Ministry of International Trade and Industry, 3,360 Million from the general account for nuclear items, 57,500 Million from the special account for power source development and 99,900 Million for fiscal investments and loans. In the Science and Technology Agency, compared with the last fiscal year, the appropriations have been especially increased for the research and development of nuclear fusion in the Japan Atomic Energy Research Institute. In the Ministry of ITI, the distinctive budgetary features are those for streamlining the safety regulation administration, uranium extraction from sea water, and thermal effluent management. The 1979 government nuclear budget is described as follows: in the STA, Japan Atomic Energy Research Institute, Power Reactor and Nuclear Fuel Development Corporation, Japan Nuclear Ship Development Agency, and National Institute of Radiological Sciences; in the MITI, general account, special account, and fiscal investments and loans; the items in other ministries. (J.P.N.)

[en] In order to attain the inspection goal, it is necessary to utilize a lot of inspection efforts at Tokai Reprocessing Plant (TRP), where usually about 800 person-days/year are required. This inspection efforts are amounts to 8% of the all inspection efforts of the IAEA in '92. The main reason of this is that, during the campaign, the inspection activities are required to cover a 24 hour/day operation. Then we have studied how the inspection scheme can be streamlined with maintaining the safeguards criteria requirements as it is, and summarized R and D factors for its inspection scheme. The essence of the streamlining is to apply unattended inspection mode to the sampling activities for input and output accounting. By this inspection scheme we expect that the inspection efforts can be reduced about 300 person-days/year at TRP. (author)

[en] The FBR is the most practical means of utilizing the uranium resources as effectively as possible. The condition of first priority for the realization of this type of reactor is to make it competitive with LWRs. It is necessary to improve its economy with a guarantee that its level of safety is not lower than that of LWRs. For this purpose, further upgrading of FBR performance so far established and the application of innovative technology are required. Main tasks to be undertaken in the field of materials and chemistry of sodium technology can be summarized as follows: - Further improvement of computer codes by detailed experiments and completion of data base systems. These are generally desirable in all fields so far established. - Standardization of sensors or processes of instrumentation (for example, purity measurements). - Contribution of knowledge on sodium technology to a rational basis for safety standards for FBRs. - Identifying problems which may cause possible difficulty during plant life in long-term service, and pursuing R and D programs to solve them. - The application of innovative sodium technology to FBR