Practice for reducing contamination of controlled area under the influence of Fukushima nuclear accident

Yoshitomi, Hiroshi; Tatebe, Yosuke; Kawai, Keiichi; Kowatari, Munehiko

Progress in Nuclear Science and Technology (Internet), 4, p.81 - 84, 2014/04

http://www.aesj.or.jp/publication/pnst004/data/081_084.pdf

The Facility of Radiation Standards of the Japan Atomic Energy Agency provides various radiation fields for calibration and testing. It is located about 120 km away from Fukushima Dai-ichi Nuclear Power Plant, and radioactive materials discharged by the Fukushima nuclear accident contaminated around the FRS, even inside the building including radiation controlled areas. One month after the accident, the maximum contamination level in the controlled areas was 3.8 Bq/cm. Cs, Cs, I, Te and I were detected by spectrometry using an HPGe detector. However, contamination in controlled areas under widely contaminated environment have not been discussed in detail. As for FRS, practices for reducing contamination in the controlled areas were necessary to avoid the influence of the contamination to the calibration works. These practices described that the following two approaches were effective: (1) decontamination of the controlled areas by wiping out with wet cloth or steam cleaners, and (2) to prevent the dust with radioactive materials from letting in the controlled areas. As a result, surface contaminates inside the controlled areas were reduced to be dozens of times lower as compared with outside.

Replacement of the criticality accident alarm system in the Tokai reprocessing plant

Sanada, Yukihisa; Nemoto, Makoto*; Suzuki, Kei*; Kawai, Keiichi*; Momose, Takumaro

Proceedings of 12th International Congress of the International Radiation Protection Association (IRPA-12) (CD-ROM), 7 Pages, 2008/10

http://www-pub.iaea.org/MTCD/Publications/PDF/Pub1460_web.pdf

The purpose of this study is to show the design principle and the determination procedures for the adequate relocation of the CADs in TRP. When the alarm trip point was 2.0 mGy/h, it is possible to detect a criticality accident even under conservative conditions (i.e. : 10 m distances from the equipment to the CAD and 140 cm concrete shield between them; neutron: 15 m distances and both 60 cm concrete shield and 60 cm steel shield). Consequently, it was found the seven CADs at these locations could monitor PCDF adequately. This study was reflected in the determination of the new CAD location.

Development of new -ray measurement methods with radon suppression focused on pulse time interval

Sanada, Yukihisa; Nohara, Naofumi*; Adachi, Yasuyuki*; Nemoto, Kazuhiko*; Kawai, Keiichi*; Kobayashi, Hirohide; Hashimoto, Tetsuo*

JAEA-Technology 2005-009, 33 Pages, 2006/01

JAEA-Technology-2005-009.pdf:1.42MB

An -ray measurement methods based on analyzing the time interval of pulses was newly developed. This method was developed aiming to suppress the background counts originated in progeny of uranium series. A delayed coincidence and time interval analysis (TIA) methods have been applied to measure a-b decay successive events (correlated events) on microsecond time-scale (164s). The measurement system have such functions with silicon detectors was developed intending to shorten the dead time. The basic performance of the system was examined by using Th electrodeposited sources. Follows were obtained in this work : The theory of measurement Po using TIA methods was established. Measurement system of Po was developed. Conformation methods of correlated events by using Th electrodeposited sources was suggested. The efficiency of correlated events in aerosol samples was estimated. The methods to measure correlated events was indicated by addition of Th. The method of subtracting the progenies of the thorium series are to examine.

Evaluations of heavy nuclide data for JENDL-3.3

Kawano, Toshihiko*; Matsunobu, Hiroyuki*; Murata, Toru*; Zukeran, Atsushi*; Nakajima, Yutaka*; Kawai, Masayoshi*; Iwamoto, Osamu; Shibata, Keiichi; Nakagawa, Tsuneo; Osawa, Takaaki*; et al.

JAERI-Research 2003-026, 53 Pages, 2003/12

JAERI-Research-2003-026.pdf:2.48MB

New evaluations of neutron nuclear data for Uranium, Plutonium, and Thorium isotopes which are essential for applications to nuclear technology were carried out for the Japanese Evaluated Nuclear Data Library, JENDL-3.3. The objectives of the current release of JENDL were to fix several problems which have been reported for the previous version, to improve the accuracy of the data, and to evaluate covariances for the important nuclides. Quantities in JENDL-3.2 were extensively re-evaluated or replaced by more reliable values. The heavy nuclide data in JENDL-3.3 were validated with several benchmark tests, and it was reported that the current release gave a good prediction of criticalities.

JENDL PKA/KERMA file for IFMIF project

Fukahori, Tokio; Chiba, Satoshi; Shibata, Keiichi; Ikeda, Yujiro; Aruga, Takeo; Watanabe, Yukinobu*; Murata, Toru*; Yamano, Naoki*; Kawai, Masayoshi*

Reactor Dosimetry: Radiation Metrology and Assessment (ASTM STP 1398), p.591 - 598, 2001/00

no abstracts in English

Evaluation of fission cross sections and covariances for U,U,U,Pu,Pu,and Pu

Kawano, Toshihiko*; Matsunobu, Hiroyuki*; Murata, Toru*; Zukeran, Atsushi*; Nakajima, Yutaka*; Kawai, Masayoshi*; Iwamoto, Osamu; Shibata, Keiichi; Nakagawa, Tsuneo; Osawa, Takaaki*; et al.

JAERI-Research 2000-004, p.76 - 0, 2000/02

JAERI-Research-2000-004.pdf:2.39MB

no abstracts in English

Japanese evaluated nuclear data library, JENDL-3

Asami, Tetsuo*; Iijima, Shungo*; ; Ihara, Hitoshi; Kawai, Masayoshi*; ; Komuro, Yuichi; Shibata, Keiichi; Takano, Hideki; ; et al.

Nihon Genshiryoku Gakkai-Shi, 31(11), p.1190 - 1217, 1989/11

https://doi.org/10.3327/jaesj.31.1190

no abstracts in English

Influence of difference in structure of the beta calibration sources on calibration for personal dosimeters

Yoshitomi, Hiroshi; Tatebe, Yosuke; Kowatari, Munehiko; Kawai, Keiichi; Miyauchi, Hideaki; Yoshizawa, Michio

no journal, , 

no abstracts in English

An Attempt to introduction of the performance index for dose rate meter

Yoshitomi, Hiroshi; Tatebe, Yosuke; Kawai, Keiichi; Kowatari, Munehiko; Yoshizawa, Michio

no journal, , 

no abstracts in English

Control of biodistribution of Rhenium-186-MAG3-conjugated bisphosphonate using a competitive inhibitor of protein binding

Ogawa, Kazuma*; Mukai, Takahiro*; Kawai, Keiichi*; Takamura, Norito*; Hanaoka, Hirofumi*; Hashimoto, Kazuyuki; Saji, Hideo*

no journal, , 

Previously, based on the concept of bifunctional radiopharmaceuticals, we developed a highly stableRe-MAG3 complex conjugated bisphosphonate (Re-MAG3-HBP) for treatment of the painful bone metastases. We assumed that competitive inhibitors of protein binding might be useful forRe-MAG3-HBP because it has been reported that the concurrent administration between Tc-MAG3 and drugs with high protein binding affinity produced competitive displacement at the specific binding sites and enhanced total clearance and tissue distribution. In this study, the displacement effect between Re-MAG3-HBP and several protein binding inhibitors were investigated. Effects of each competitive protein binding inhibitor were examined in in vitro human serum. Bucolome, ceftriaxione and cefazolin as displacers of human serum albumin (HSA) binding site I, and ibuprofen as a displacer of HSA binding site II were added to each serum before addition of Re-MAG3-HBP. As a result of in vitro study, the free fraction rate of Re-MAG3-HBP was significantly increased by the addition of ceftriaxone. In biodistribution studies, the loading ceftriaxone enhanced the clearance of radioactivity of Re-MAG3-HBP in blood and non-target tissues without the reduction of the bone accumulation. These findings suggested that the use of a protein binding competitive inhibitor would be effective for lowering the side effects of Re-MAG3-HBP.