Stepwise renewal of JRR-3 process control computer system

Isaka, Koji; Suwa, Masayuki; Kimura, Kazuya; Suzuki, Makoto; Ikekame, Yoshinori; Nagadomi, Hideki

JAEA-Technology 2021-039, 48 Pages, 2023/02

JAEA-Technology-2021-039.pdf:6.97MB

JRR-3 Process control system is used from the initial criticality (1990) after remodeling JRR- 3 as equipment used for monitoring and control of flow rate, temperature, pressure, water level, etc. of coolant and operation of nuclear reactor equipment, and it became necessary to renew as the aging progressed and spare parts could not be obtained sufficiently. Upon renewal, from the viewpoint of ensuring conservation of the core such as decay heat removal and minimizing the impact on reactor users and minimizing costs, it is important not to stop long-term reactor shutdown we planned to divide it into three stages and make it on a continuous basis. This report summarizes the renewal plan and renewal work divided into three stages.

Experiments of JRR-4 low-enriched-uranium-silicied fuel core

Hirane, Nobuhiko; Ishikuro, Yasuhiro; Nagadomi, Hideki; Yokoo, Kenji; Horiguchi, Hironori; Nemoto, Takumi; Yamamoto, Kazuyoshi; Yagi, Masahiro; Arai, Nobuyoshi; Watanabe, Shukichi; et al.

JAEA-Technology 2006-028, 115 Pages, 2006/03

JAEA-Technology-2006-028.pdf:7.96MB

JRR-4, a light-water-moderated and cooled, swimming pool type research reactor using high-enriched uranium plate-type fuels had been operated from 1965 to 1996. In order to convert to low-enriched-uranium-silicied fuels, modification work had been carried out for 2 years, from 1996 to 1998. After the modification, start-up experiments were carried out to obtain characteristics of the low-enriched-uranium-silicied fuel core. The measured excess reactivity, reactor shutdown margin and the maximum reactivity addition rate satisfied the nuclear limitation of the safety report for licensing. It was confirmed that conversion to low-enriched-uranium-silicied fuels was carried out properly. Besides, the necessary data for reactor operation were obtained, such as nuclear, thermal hydraulic and reactor control characteristics. This report describes the results of start-up experiments and burnup experiments. The first criticality of low-enriched-uranium-silicied core was achieved on 14th July 1998, and the operation for joint-use has been carried out since 6th October 1998.

Current status and issues relative to LEU spent fuel of JMTR and JRR-3

Izumo, Hironobu; Hanawa, Nobuhiro; Nagadomi, Hideki; Torii, Yoshiya; Inoue, Takeshi; Kawamura, Hiroshi

no journal, , 

The refurbishment works of JMTR had been completed as scheduled. The renewed JMTR operation is expected to start as soon as possible after check for earthquake effect etc, and will be utilized mainly for safety evaluation on LWRs and Mo production by without uranium target. JRR-3 has been used mainly for neutron beam experiments and radio isotope production. The number of LEU silicide spent fuels (SFs) stored at the reactor facilities in JAEA will increase in future by the JMTR restart. It will be one of the key issues to decrease the number of stored SFs for stable reactor operation. Consequently, it is thought that accomplishment of the FRRSNF acceptance program and its extension or alternative measures are very important.

Status of JRR-3 corresponding to new regulatory standards, 1; Outlie

Wada, Shigeru; Kawamura, Sho; Suzuki, Makoto; Kimura, Kazuya; Nagadomi, Hideki

no journal, , 

In 1990, JRR-3 was modified for upgrade and resumed its operation as a high performance and multi-purpose research reactor with thermal power of 20MW. Since modified, JRR-3 has been utilized for neutron beam experiments, neutron activation analysis, production of radioisotopes, neutron transmutation doping of silicon, fuel and material irradiation, etc. The maximum thermal power of JRR-3 is 20MW. JRR-3 is a light water moderated and cooled, pool type research reactor using low-enriched silicide fuel. JRR-3 had been confirmed conformation to new regulations on research and test reactor facilities which came into force on 18th December 2013. The application has been submitted to NRA on 26th September 2014. Finally, installment license of JRR-3 was permitted November in 2018. Restart the JRR-3 is planted in the few years.