Conceptual design of multipurpose compact research reactor; Annual report FY2011

Watahiki, Shunsuke; Hanakawa, Hiroki; Imaizumi, Tomomi; Nagata, Hiroshi; Ide, Hiroshi; Komukai, Bunsaku; Kimura, Nobuaki; Miyauchi, Masaru; Ito, Masayasu; Nishikata, Kaori; et al.

JAEA-Technology 2013-021, 43 Pages, 2013/07

JAEA-Technology-2013-021.pdf:5.12MB

The number of research reactors in the world is decreasing because of their aging. On the other hand, the necessity of research reactor, which is used for human resources development, progress of the science and technology, industrial use and safety research is increasing for the countries which are planning to introduce the nuclear power plants. From above background, the Neutron Irradiation and Testing Reactor Center began to discuss a basic concept of Multipurpose Compact Research Reactor (MCRR) for education and training, etc., on 2010 to 2012. This activity is also expected to contribute to design tool improvement and human resource development in the center. In 2011, design study of reactor core, irradiation facilities with high versatility and practicality, and hot laboratory equipment for the production of Mo-99 was carried out. As the result of design study of reactor core, subcriticality and operation time of the reactor in consideration of an irradiation capsule, and about the transient response of the reactor to the reactivity disturbance during automatic control operation, it was possible to do automatic operation of MCRR, was confirmed. As the result of design study of irradiation facilities, it was confirmed that the implementation of an efficient mass production radioisotope Mo-99 can be expected. As the result of design study with hot laboratory facilities, Mo-99 production, RI export devised considered cell and facilities for exporting the specimens quickly was designed.

Conceptual design of multipurpose compact research reactor; Annual report FY2010 (Joint research)

Imaizumi, Tomomi; Miyauchi, Masaru; Ito, Masayasu; Watahiki, Shunsuke; Nagata, Hiroshi; Hanakawa, Hiroki; Naka, Michihiro; Kawamata, Kazuo; Yamaura, Takayuki; Ide, Hiroshi; et al.

JAEA-Technology 2011-031, 123 Pages, 2012/01

JAEA-Technology-2011-031.pdf:16.08MB

The number of research reactors in the world is decreasing because of their aging. However, the planning to introduce the nuclear power plants is increasing in Asian countries. In these Asian countries, the key issue is the human resource development for operation and management of nuclear power plants after constructed them, and also the necessity of research reactor, which is used for lifetime extension of LWRs, progress of the science and technology, expansion of industry use, human resources training and so on, is increasing. From above backgrounds, the Neutron Irradiation and Testing Reactor Center began to discuss basic concept of a multipurpose low-power research reactor for education and training, etc. This design study is expected to contribute not only to design tool improvement and human resources development in the Neutron Irradiation and Testing Reactor Center but also to maintain and upgrade the technology on research reactors in nuclear power-related companies. This report treats the activities of the working group from July 2010 to June 2011 on the multipurpose low-power research reactor in the Neutron Irradiation and Testing Reactor Center and nuclear power-related companies.

Investigation on integrity of JMTR concrete structure

Miyauchi, Masaru; Kimura, Tadashi; Oto, Tsutomu; Nemoto, Nobuaki; Tobita, Kenji; Fukasaku, Akitomi; Takahashi, Kunihiro

JAEA-Review 2010-008, 106 Pages, 2010/06

JAEA-Review-2010-008.pdf:8.89MB

An integrity investigation was carried out for the JMTR Concrete Structure (Vent Stack, Trench, Canal Building, Filter Bank), which was the concrete structure and would be used for the long-term after JMTR restart, before the repair or replacement work of the JMTR related facilities that had begun in FY2007. In the integrity investigation, the concrete surface deterioration, the rebound number (nondestructive strength test), compressive strength using drilled concrete core test piece, the static modules of elasticity, the carbonation depth, the reinforced bar corrosion and the chloride ion content were investigated respectively and the integrity of concrete was confirmed. After the investigation, repair works such as re-painting of the Vent Stack and Trench were carried out from the viewpoint of prevention of flaking off, floating of the painting and the thinning due to the investigation results. In order to use the JMTR concrete structure continuously for long-term, it is important for maintaining the integrity of a concrete structure by the periodical maintenance and the repairing work including the building outer-wall surface painting that has been conducted up to now.

Investigation on integrity of JMTR UCL elevated water tank

Kimura, Tadashi; Oto, Tsutomu; Miyauchi, Masaru; Nemoto, Nobuaki; Tobita, Kenji; Fukasaku, Akitomi; Takahashi, Kunihiro

JAEA-Review 2010-001, 27 Pages, 2010/03

JAEA-Review-2010-001.pdf:18.81MB

In order to investigate an integrity of the UCL (Utility Cooling Line) elevated water tank to be used for a long term after the JMTR restart, investigation on the base of the UCL elevated tank, especially for the part which had a significant aged effect, was carried out before the refurbishment work of the JMTR related facilities which had begun in FY2007. In the integrity investigation, it was confirmed that some part of the base bolts had significant aged effects, there were no evidence of crack and false indication in the welding region though thinning were observed in some parts of the base plate and the surrounding plate. After the investigation, repair works such as re-painting of the UCL elevated water tank were carried out from the viewpoint of prevention of flaking off, floating of the painting and the thinning due to corrosion based on the investigation results. In order to maintain the integrity of the UCL elevated tank, the periodical maintenance and the repair works of the base of the UCL elevated tank are important for continuous use of it in future.

The Outline of investigation on integrity of JMTR concrete structures, cooling system and utility facilities

Ebisawa, Hiroyuki; Hanakawa, Hiroki; Asano, Norikazu; Kusunoki, Hidehiko; Yanai, Tomohiro; Sato, Shinichi; Miyauchi, Masaru; Oto, Tsutomu; Kimura, Tadashi; Kawamata, Takanori; et al.

JAEA-Technology 2009-030, 165 Pages, 2009/07

JAEA-Technology-2009-030.pdf:69.18MB

The condition of facilities and machinery used continuously were investigated before the renewal work of JMTR on FY 2007. The subjects of investigation were reactor building, primary cooling system tanks, secondary cooling system piping and tower, emergency generator and so on. As the result, it was confirmed that some facilities and machinery were necessary to repair and others were used continuously for long term by maintaining on the long-term maintenance plan. JMTR is planed to renew by the result of this investigation.

Applicability of X-ray radiography for integrity assessment of aged pipes in the JMTR

Ito, Masayasu; Taguchi, Taketoshi; Miyauchi, Masaru; Sozawa, Shizuo

no journal, , 

It has been 45 years since the first criticality of JMTR in March 1968, and unfortunately, two contaminated water leakages from the stainless steel pipes occurred in 2012. Results of the investigation showed that the cause of the leakages was cracks due to stress corrosion cracking (SCC) from the outer surface, and crevice corrosion from the inner surface, respectively. Although visual inspection for these pipes had been carried out as regular inspections before the leakages occurred, these cracks were invisible to the naked eye. Since the X-ray radiography can detect internal flaws/cracks, was investigated as a non-destructive inspection to assess the integrity of the aged liquid waste transfer pipes in the JMTR. In this presentation, observation results by the X-ray radiography and the X-ray CT will be reported, and the applicability of the X-ray radiography.