A Ni-base alloy weld, including cracks due to stress corrosion cracking found in the reactor internal of the oldest BWR in Japan, Tsuruga unit 1, in 1999, was examined by three (3) types of UT method. After this examination, a depth of each crack was confirmed by carrying out a little excavation with a grinder and PT examination by turns until each crack Hisappeared. Then, the depth measured by the former method was comp ared with the one measured by the latter method. n this fashion, performances of the ...
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Evaluation on Ultrasonic Examination Methods applied to Ni-base Alloy Weld including Cracks dueto Stress Corrosion Cracking found in BWR Reactor Internal

The current edition of “Guideline of Inspection and Evaluation for Reactor Internals issued by Japan Nuclear Safety Institute (JANSI) consists of inspection target, inspection method, and evaluation. Recently, the guideline is revised based on the safety function of the Reactor Internals, domestic operation experience, and the new knowledge. In this report, summary of “Guidelines of Inspection and Evaluation for Reactor Internals [Core Shroud] and [Shroud Support]....
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Guideline for BWR Inspection Program Revision Policy of Guidelines for Core Shroud and Shroud Support

During the field work of the core shroud replacement project of Tsuruga power station unit 1 in December 1999, when it had almost 30 years operation experience since the commencement of commercial operation in March 1970, many cracks were detected visually at the shroud support to reactor pressure vessel (RPV) weld metal (Ni-based alloy: Alloy 182) and confirmed with penetrant testing as well as by metallographic observation. Almost all cracks were found to propagate in the axial direction of the RPV ...
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Evaluation on Crack Growth Analysis Model based on the Knowledge obtained from Stress Corrosion Cracking in Ni-based Alloy used for a Long Time in a BWR

Many Swagelok connections are used in the instrumental tube pipe of Nuclear power plant because Swagelok conne ion is easy to put on and take off quickly. Although Swagelok connection is easy handling, it occurs very sma ll amount of leakage in some case. For the purpose of development of quick repair method for small amount leak e of Swagelok connection, we considered the base technique about the miniature cramp for Swagelok connection....
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Development of Miniature Cramp for Swagelok Connection Temporary Repair

Needs for development of practical technologies such as repair and mitigation, and necessity of conceptual summarization on those technologies are proposed. Temporary repair technology is focused in particular, to discuss its development needs for simple application and effectiveness for short period. Next, aggressive movements for standardization of allowable leak rules and repair technologies including the tentative ones in the United States are pointed out to find a promising orientation of utilizing...
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Needs for Temporary Repair Technology and Concept of Mitigation

The guideline committee for the inspection and evaluation of Reactor Vessel Internals of JANSI (Japan Nuclear Safety Institute) has been developing many guidelines based on principle which the conservative methodology, and covered both individual inspection method of reactor internals and application of repair methods for reactor internals. In this paper, some aspects of the JANSI-VIP-21 (Guidelines for the inspection and evaluation of Reactor Vessel Internals, revised Mar.2017) which is summary document o...
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Outlines of Guidelines for the Inspection and Evaluation of Reactor Vessel Internals

“The guideline committee for the inspection and evaluation of Reactor Vessel Internals” of JANSI (Japan Nuclear Safety Institute) has been developing many guidelines based on principle which the conservative methodology, and covered both individual inspection method of reactor internals and application of repair methods for reactor internals. In this paper, some aspects of the JANSI-VIP-03 (Guidelines for the inspection and evaluation of Reactor Vessel Internals, revised Dec.2013) which is summary docu...
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Outlines of Guidelines for the Inspection and Evaluation of Reactor Vessel Internals

Working Group on Application Enhancement of Repair Replacement Technology has been established since September 2015, for the purpose of studying specific measures to create an environment that Japanese utilities can easily make corrective actions such as repair replacement technology applicable to Nuclear Power Plant to improve the safety of their own plants, and meetings have been held five times until the end of April 2016. In this paper, discussions on the WG meetings so far are shown, as well as th...
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Current Status of WG on Application Enhancement of Repair Replacement Technology

A Ni-base alloy weld, including cracks due to stress corrosion cracking found in the reactor internal of the oldest BWR in Japan, Tsuruga unit 1, in 1999, was examined by three (3) types of UT method. After this examination, a depth of each crack was confirmed by carrying out a little excavation with a grinder and PT examination by turns until each crack disappeared. Then, the depth measured by the former method was compared with the one measured by the latter method. In this fashion, performances of...
英字タイトル:
Evaluation on Ultrasonic Examination Methods applied to Ni-base Alloy Weld including Cracks due to Stress Corrosion Cracking found in BWR Reactor Internal