Nuclear Regulation Authority has been working on new regulation considering lesson learnt from Fukushima Daiichi accident, state-of-the-art technical knowledge, and trends of regulation in the other countries including safety standards defined by international organization such as IAEA. We, Kyushu EPCO, have also been conducting many different measures considering Fukushima Daiichi accident, and would like to introduce those recent activities. ...
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Measures to further Improve safety and reliability of Kyushu Electric Power Co.,Inc.

In the new regulation formulated after the accident at Fukushima Daiichi Nuclear Power Plant, it is demanded that the glove box consists of incombustible or noncombustible materials. However, combustible acryl materials are used for many glove boxes installed in nuclear fuel cycle facilities. In this work, the glove box acryl panel has been replaced to incombustible material with accordance to the new regulation. The new panels have been manufactured by polycarbonate which satisfied the UL94 V-0 incombusti...
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Replacement of the Glove Box Panel in Nuclear Fuel Reprocessing Facility

Chloroprene rubber gaskets are often used to seal the glove box body and its panels. Such gaskets are deformed with compressive pressure and its elastic restoring force keeps sealing property. Therefore, gaskets play an important role in glove box sealing. However, physical properties of those used in glove box have not reported so far. In this study, hardness, elongation, tensile strength and compression set are investigated and its sealing performances are evaluated. The gaskets samples are taken fro...
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Physical property of seal-gasket for glove box panel in reprocessing facilities

Radioactive liquid waste from the Tokai Reprocessing Facility Analytical Laboratory is temporarily stored in intermediate waste storage tanks by using receiving valves. Then, the liquid waste is transferred to liquid treatment facility by using liquid feed valves. The deterioration of the gasket part of these valves (leakage of waste liquid) was confirmed in 2004. Since then, the material of gaskets was changed from polyethylene to polytetrafluoroethylene(PTFE). In 2016, the gaskets were replaced by periodi...
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Physical property evaluation of valve seal material at analytical radioactive liquid waste storage tanks in reprocessing facility

加圧水型原子炉(PWR)の応力腐食割れに対して国内外で様々な工法が開発され、実機に適用されている。原子炉容器出入口管台の600合金使用部位の応力腐食割れ対策として、原子炉容器出入口管台 INLAY 工法が開発され、実機への適用実績がある。2018年3月～4月に九州電力掬川内原子力発電所1号機に対し、本工法が適用された。...

An effective countermeasure against stress corrosion cracks in nozzle welds is to improve the surface residual stress. A new tec hnique of the ultrasonic shot peening (USP) for steam generator (SG) nozzles will be introduced as a method to improve the residu al stress on Alloy 600 Welds. This method changes the compressive stress by applying plastic strain to the surface via the impac t force of the shot material during the shot peening. We have successfully performed 14 USP operations in actual plants in ...
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Application of Ultrasonic Shot Peening To Steam Generator Nozzles

Cladding Operation using alloy 690 with high SCC resistance is an effective measure for protection against PWSCC of all oy 600. To apply the Cladding Operation for Reactor Vessel Outlet Nozzle, Temper Bead Technique for low alloy steel was established and some kinds of remote controlled tools were developed. The first Cladding Operation for Reactor Vessel Ou tlet Nozzle was applied to a Japanese PWR Plant in November 2004,and the Cladding Operation was successfully completed. ...
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The Cladding of PWR Reactor Vessel Outlet Nozzle

In domestic plants, sea water is used for cooling the auxiliary coolers, the lining of sea water pipe inside as anticorrosion materials is used with rubbers, polyethylene, epoxy resins, and etc. And the lining conditions are mainly confirmed by direct visual inspection. In the sea water pip g, the once occurred the small through-holes(pin-hole) accelerate the piping degradation caused by corrosion and it is important to confirm the deterioration condition of lining at an early st age. However, to confirm ...
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The Advancement of lining inspection technology inside sea water piping

Abstract In operating of nuclear power plants, it is required not only to preserve and improve the reliability and safety, but also to introduce more efficient and lower cost maintenance strategy simultaneously, due to t he power trading deregulation in recent years. In addition, as the number of experienced operators / maintenance personnel decreases, comprehensive implementation of objective and transparent information provision syste m on plant operation and maintenance (O&M) being compliant with the la...
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Development of Remote Operation & Maintenance Support service system