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Nakamura, Hironobu; Beddingfield, D. H.*; Nakamichi, Hideo; Mukai, Yasunobu; Yoshimoto, Katsunobu
IAEA-CN-184/59 (Internet), 7 Pages, 2010/11
In order to reduce radioactivity of liquid waste generated at PCDF, a neutralization precipitation processes by sodium hydroxide precipitation is used. We call the precipitate after calcining as Sludge. The Pu amount in the sludge sample is normally determined by sampling and DA. The sludge contains many chemical components. For example, Pu, U, Am, SUS components, halogens, NaNO
(main component), residual NaOH, and moisture. They are mixed together as an impure heterogeneous sludge sample. As a result, there is a large uncertainty in the sampling and DA that is currently used at PCDF. In order to improve the material accounting in PCDF, we performed a feasibility study using neutron multiplicity assay for impure sludge samples. We have measured selected sludge samples using a commercial multiplicity counter which is called FCAS (Fast Carton Assay System) which was designed by JAEA and Canberra. For unknown samples, using 14-hour measurements, we could obtain quite low statistical uncertainty on Doublesand Triples count rate although the alpha value is extremely high and FCAS efficiency is relatively low for typical multiplicity counters. Despite the detector efficiency challenges and the material challenges, we have been able to obtain assay results that greatly exceed the accountancy requirements for retained waste materials.
Miyaji, Noriko; Kawakami, Yukio; Koizumi, Atsuhiro; Otsuji, Ayako*; Sasaki, Keiichi*
IAEA-CN-184/60 (Internet), 6 Pages, 2010/11
FMF at Oarai Research and Development Center (JNC-2 site) conducts post irradiation examinations (PIE) of fuel assemblies irradiated in Joyo. After the PIEs, the tested material is shipped back to a Joyo spent fuel pond. For the IAEA to apply the integrated safeguards approach (ISA) to the FMF, a new verification system on material transfer between Joyo and the FMF has been established. Gross defect verification of the nuclear material contained in the cask is performed at the time of short notice random interim inspections (RIIs) by measuring the surface neutron dose rate of the cask, filled with water to reduce radiation. As the result of performing a series of preliminary tests, this system could be used for the verification purpose under the ISA. It is clear that application of the system under the ISA provides the transparency of the material shipping and receiving process would be improved.
Suzuki, Mitsutoshi; Izumi, Yoshinori; Kimoto, Toru; Naoi, Yosuke; Inoue, Takeshi; Hoffheins, B.
IAEA-CN-184/64 (Internet), 8 Pages, 2010/11
In support of the 3S initiative, Japan Atomic Energy Agency (JAEA) has been conducting detailed analyses of the R&D programs and cultures of each of the S areas to identify overlaps where synergism and efficiencies might be realized, to determine where there are gaps in the development of a mature 3S culture, and to coordinate efforts with other Japanese and international organizations. Lessons learned in these activities can be applied to developing more efficient and effective 3S infrastructures for incorporating into Safeguards by Design methodologies. In this presentation, a risk-informed approach regarding integration of 3S will be introduced. An initial examination of incident probability and postulated consequence analyses, which are tools familiar to the nuclear safety culture, will be applied to predict and evaluate inherent uncertainties of proliferation and security risks.
Ninagawa, Junichi; Nagatani, Taketeru; Asano, Takashi; Fujiwara, Shigeo
no journal, ,
no abstracts in English
Kuno, Takehiko; Okano, Masanori; Masui, Kenji; Suzuki, Yutaka; Yamada, Keiji; Watahiki, Masaru; Hiyama, Toshiaki
no journal, ,
no abstracts in English
