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Takeuchi, Tomoaki; Shibata, Akira; Nagata, Hiroshi; Kimura, Nobuaki; Otsuka, Noriaki; Saito, Takashi; Nakamura, Jinichi; Matsui, Yoshinori; Tsuchiya, Kunihiko
Proceedings of 3rd Asian Symposium on Material Testing Reactors (ASMTR 2013), p.52 - 58, 2013/11
In-pile instrumentation systems in present LWR's are indispensable to monitor all situations during reactor operation and reactor shut down. However, those systems did not work sufficiently under the conditions like as the severe accident at the Fukushima Dai-Ichi Nuclear Power Station. Therefore, based on the irradiation measurement technique of experiences accumulated in JMTR, the developments of reactor instrumentation systems to prevent severe core damage accident in advance have been started. The development objects are four instrumentation systems, which are a solid electrolysis type hydrogen concentration sensor, a water gauge of thermocouple type equipped with the heater, a 
-ray detector of self-powered type SPGD, and an image analysis system of Cherenkov light for quantification of in-reactor information by CCD cameras. After the developments, the in-pile verification tests of four instrumentation systems are planned at the JMTR.
Tc production from (n,)
Mo based on solvent extractionKimura, Akihiro; Awaludin, R.*; Shiina, Takayuki*; Tanase, Masakazu*; Kawauchi, Yukimasa*; Gunawan, A. H.*; Lubis, H.*; Sriyono*; Ota, Akio*; Genka, Tsuguo; et al.
Proceedings of 3rd Asian Symposium on Material Testing Reactors (ASMTR 2013), p.109 - 115, 2013/11
JP, 2011-173260 
Patent publication (In Japanese)
Tc is generated by decay of Mo. Production of Mo is carried out by (n,f) method with high enriched uranium targets, and the production are currently producing to meet about 95% of global supply. Recently, it is difficult to carry out a stable supply for some problems such as aging of reactors etc. Furthermore, the production has difficulties in nuclear proliferation resistance etc. Thus, (n,) method has lately attracted considerable attention. The (n,) method has several advantages, but the extremely low specific activity makes its uses less convenient than (n,f) method. We proposed a method based on the solvent extraction, followed by adsorption of Tc with alumina column. In this paper, a practical production of Tc was tried by the method with 1Ci of Mo produced in MPR-30. The recovery yields were approximately 70%. Impurity of Mo was less than 4.0
10
% and the radiochemical purity was over 99.2%.
pellets from different MoO powdersNishikata, Kaori; Kimura, Akihiro; Kakei, Sadanori*; Niizeki, Tomotake*; Ishida, Takuya; Yoshinaga, Hideo*; Hasegawa, Yoshio*; Tsuchiya, Kunihiko
no journal, ,
Every year in Japan, nuclear medical of about 900,000 cases are carried out using technetiume-99m (Tc). It is ranked as the second in the world. But all of the Tc is imported from the other countries. Therefore, we are developing the (n, ) method for Mo production, as part of "increase of industrial use" in resumed operations after restart of Japan Materials Tasting Reactor (JMTR). In the study to establish the Mo production method through the (n, ) process domestically using the JMTR, three different MoO powders such as fresh, recycled and 
Mo enriched ones were selected, and characterized as in SEM and sintering. As a result, the high dense MoO pellet manufactured by the fresh powder attained over 90%T. D. at the sintering temperature of 500
C. On the other hand, pellets manufactured by the other powders needs sintering temperature above 580C to attain over 90%T.D., resulting in an influence on the particle size and shape dependences for the sintering property.
Kaminaga, Masanori; Tanimoto, Masataka; Ooka, Makoto; Ishihara, Masahiro; Kusunoki, Tsuyoshi; Naito, Akinori; Araki, Masanori
no journal, ,
JMTR in JAEA is a light water cooled tank type reactor with 50MW thermal power. From its first criticality in March 1968, the JMTR has been utilized for fuel/material irradiation examinations of LWRs, HTGR and fusion reactor as well as for RI productions under its transportation advantage that the JMTR and hot laboratory is connected by a canal. In August 2006, the JMTR operation was once stopped in order to have a check & review for the reoperation which was discussed by internal as well as external committees. As a result of the national discussion, the JMTR was determined, finally, to restart after necessary refurbishment works. The refurbishment was started from the beginning of JFY 2007, and replaced were motors of primary and secondary cooling pumps, nuclear instrumentation system, and so on. The refurbishment was finished in March 2011 as planned. Unfortunately, at the end of the JFY 2010 on March 11, the Great-Eastern-Japan-Earthquake occurred, and functional tests before the JMTR restart were delayed by the earthquake. Seismic influence evaluation for the JMTR because of the 3.11 earthquake was carried out with directions of the government. As a result, integrity of the JMTR reactor facilities has been evaluated and verified for re-operation. Seismic influence evaluation results were reported to the regulatory agency on Sep.7, 2012. Validation evaluation of the seismic influence evaluation results is still underway by the NRA. On the other hand, new regulatory requirements for research and test reactors will be established on Dec.18, 2013 by the NRA. JMTR will be re-started after the completion of validation evaluation of the seismic influence evaluation results and confirmation of suitability against the new regulatory requirements for research and test reactors by the NRA. The renewed JMTR will be operated for a period of about 20 years until around JFY 2030.