Annual report of Nuclear Emergency Assistance and Training Center (April 1, 2008 - March 31, 2009)

Kanamori, Masashi; Hashimoto, Kazuichiro; Terunuma, Hiroshi; Ikeda, Takeshi; Omura, Akiko; Terakado, Naoya; Nagakura, Tomohiro; Fukumoto, Masahiro; Watanabe, Fumitaka; Yamamoto, Kazuya; et al.

JAEA-Review 2009-023, 61 Pages, 2009/09

JAEA-Review-2009-023.pdf:8.49MB

When a nuclear emergency occurs in Japan, the Japan Atomic Energy Agency (JAEA) provides technical support to the National government, local governments, police, fire station and license holder etc. They are Designated Public Organizations conforming to the Basic Law on Emergency Preparedness and the Basic Plan for Disaster Countermeasures. The Nuclear Emergency Assistance and Training Center (NEAT) of JAEA provides a comprehensive range of technical support activities to an Off-Site Center in case of a nuclear emergency. Specifically, NEAT gives technical advice and information, provides for the dispatch of specialist as required, supplies emergency equipments and materials to the Joint Council of Nuclear Disaster Countermeasures, which meets at the Off-Site Center. NEAT provide various lectures and training course concerning nuclear disaster prevention for those personnel taking an active part in emergency response organizations at normal time. And NEAT researches on nuclear disaster prevention and also cooperate with international organizations. This annual report summarized the activities of JAEA/NEAT in the fiscal year 2008.

Neutron Irradiation Fields for Space Technology Application in Experimental Fast Reactor JOYO

Ito, Kazuhiro; Omura, Akiko; Hoshiya, Taiji; Mitsugi, Takeshi

Proceedings P.29-32, p.29 - 32, 2004/10

The Joyo MK-III rated power operation was started in 2003 to do various irradiation test more efficiently. Promotion of the outside use is being advanced. As the part and consideration is being advanced about formation of irradiation equipment of low flux neutron field near the space. By this report, this, JOYO as a low neutron irradiation field is introduced.

Development of the high current electron accelerator

Nomura, Masahiro; Toyama, Shinichi; ; ; Yamazaki, Yoshio; Hirano, Koichiro; Omura, Akiko

JNC TN9410 2000-007, 376 Pages, 2000/03

JNC-TN9410-2000-007.pdf:15.51MB

According to the Long-Term Program for Partitioning and Transmutation which was published by the Atomic Energy Commission in 1988, study on the transmutation using an electron accelerator, which was a part of the program, has been carried out in the O-arai Engineering Center. It is the study on converting radioactive fission products for example Strontium and Cesium to stable nuclides by photonuclear reaction caused by high energy gamma-ray made by an electron accelerator. It was thought that a 100mA-100MeV (10MW output power) accelerator would be needed in order to carry out the transmutation study in engineering phase. Therefore, development of the High-Current Electron Accelerator whose target had been 20mA-10MeV (200 kW output power) accelerator was carried out as development of elemental technologies on beam stabilization. The conceptual design of the accelerator was started in 1989. In March 1997, the main facility of this accelerator was completed. The test operation was carried out to confiim the performance of the accelerator from January, 1999 to December. As the result, an output of about 14 kW was achieved. In addition, the electron beam of 40 kW could be to accelerate in short time. In this report, the design, fabrication and evalution of performance of the facilities are presented.

Shielding evaluation on injector test in quantum technology development facility

Omura, Akiko; Toyama, Shinichi; Hasegawa, Makoto; Tani, Satoshi

JNC TN9410 99-011, 92 Pages, 1999/03

JNC-TN9410-99-011.pdf:1.7MB

JNC is investingating the best way to treat high-level radioactive nuclear waste from reactors. For basic research into the transmutation of fission products, JNC developed a high-power CW electron linac. Shielding of the radiation which leaks from beam dump and accelerating tube, it is necessary to establish the technology which can deal with the current enlargement as well as other accelerator element. In this report, shielding evaluation injector test of high-power CW electron linac is reported. As a result of the shielding evaluation, it was obtained that the management of the radiation was possible in the injector test under the dose equivalent limit. And, it was possible that problems such as operation and maintenance.

The detailed measurements of control rod worth and the reactivity coefficients in the asymmetrical control rods arrangement core of "JOYO"; The detailed control rod worth measurement(II)

Omura, Akiko; Yoshida, Akihiro; Shimakawa, Yoshio; Suzuki, Soju; Kinjo, Katsuya

PNC TN9410 93-290, 109 Pages, 1993/11

PNC-TN9410-93-290.pdf:2.76MB

The "JOYO" modification program, named the MK-III program is now under investigation. The objective of this program is to make "JOYO" more efficient irradiation facility which serve as an irradiation bed for the development of FBR fuels and materials. During the 9th annual inspection, one of six control rods has been relocated from the 3rd row to the 5th row to improve the irradiation capacity, The control rod worth and several reactivity coefficients have been measured before and after the change of the control rod arrangement in detail. The principal results of the measurements are as follows; (1)In the rod drop measurements, the effect of the relative direction of the ex-vessel neutron instrumentation system and neutron source, which affects the accuracy of the measurements, was decreased by operating the measurements based on the experience that has obtained through the last Detailed Control Rod Worth Measurement. (2)The worth of the relocated control rod has decreased to 1/3. (3)The other core neutronics characteristics were not changed by the change of the control rod arrangement. (4)The isothermal temperature reactivity coefficient for the core is -410 %k/k/C, which is almost same at every duty cycle. (5)It was confirmed that the flow rate reactivity coefficient consists of two independent factors, one may causes a reversible reactivity change and the other causes an irreversible reactivity change. Furthermore it is supposed that the threshold flow rate level that occurs an irreversible reactivity change is not the same throughout every duty cycle operation.