Examination of analytical method of rare earth elements in used nuclear fuel

Ozawa, Mayumi; Fukaya, Hiroyuki; Sato, Makoto; Kamohara, Keiko*; Suyama, Kenya; Tonoike, Kotaro; Oki, Keiichi; Umeda, Miki

Proceedings of 53rd Annual Meeting of Hot Laboratories and Remote Handling Working Group (HOTLAB 2016) (Internet), 9 Pages, 2016/11

Preparation of reference material for solidified products made from radioactive miscellaneous wastes by melting treatment; Reference material for solidified product containing -ray emitting nuclides (Joint research)

Ishimori, Kenichiro; Oki, Keiichi; Takaizumi, Hirohide; Kameo, Yutaka; Oki, Yoshiyuki*; Nakashima, Mikio

JAEA-Technology 2007-065, 20 Pages, 2008/01

JAEA-Technology-2007-065.pdf:1.4MB

In order to prepare a reference material which is used for radiochemical analysis of solidified products made from non-metallic miscellaneous low level radioactive solid wastes by melting in Nuclear Science Research Institute, Japan Atomic Energy Agency, the preparation method of the reference material was investigated. Under the optimum melting conditions obtained in this report, the reference material containing Np, Am and Cm as -ray emitting nuclides was successfully prepared. From radiochemical analysis of the reference material, the radioactive concentration of respective nuclides was determined to be 0.1880.001 Bq/g for Np, 0.3680.004 Bq/g for Am, 0.4020.010 Bq/g for Cm.

Clearance activities of concrete generated from modification of JRR-3, 2; Investigation of contamination situation of concrete

Tachibana, Mitsuo; Satoyama, Tomonori; Oki, Keiichi; Naito, Akira; Takaizumi, Hirohide; Yoshimori, Michiro; Okoshi, Minoru; Hoshi, Akiko

no journal, , 

no abstracts in English

Clearance activities of concrete generated from modification of JRR-3, 1; Over view

Yoshimori, Michiro; Satoyama, Tomonori; Oki, Keiichi; Naito, Akira; Okoshi, Minoru; Hoshi, Akiko

no journal, , 

no abstracts in English

Detailed inspection of samples taken from un-irradiated fuel assembly at 1F4, 1; Outline of inspected samples and inspection methods

Motooka, Takafumi; Endo, Shinya; Sonoda, Takashi; Oki, Keiichi; Uehara, Hiroyuki; Obata, Hiroki; Tsukada, Takashi

no journal, , 

no abstracts in English

Database for analytical data of radioactive wastes originated from the accident in Fukushima Daiichi Nuclear Power Station

Nitta, Ayako; Oki, Keiichi; Koma, Yoshikazu

no journal, , 

Various radioactive wastes generated in Fukushima Daiichi Nuclear Power Station should be safely disposed of. The properties of the wastes are required to understand. For that, the wastes are sampled and performed analyses. To utilize obtained analytical data, the database "FRAnDLi" was made to provide the data through the Internet.

Investigation of the radionuclide transfer based on the radiochemical analysis of the genuine samples at Fukushima Daiichi NPS site, 1; Research for actinide transfer to secondly waste from water treatment

Murakami, Erina; Oki, Keiichi; Takahatake, Yoko; Nitta, Ayako; Shibata, Atsuhiro; Koma, Yoshikazu

no journal, , 

no abstracts in English

Study on the radioactive contamination in the reactor building unit #4 of Fukushima Daiichi NPS

Nitta, Ayako; Hinai, Hiroshi; Shibata, Atsuhiro; Nomura, Kazunori; Oki, Keiichi; Koma, Yoshikazu

no journal, , 

Study on analysis planning for the rubble from the reactor buildings; Study on analysis planning for the rubble from the reactor buildings

Akimoto, Maya; Horita, Takuma; Nagai, Anna; Oki, Keiichi; Pyke, C.*; Hiller, P.*; Koma, Yoshikazu

no journal, , 

We investigated the planning method for analysis consistent with the characteristics of the Fukushima Daiichi NPS Wastes (1F wastes), and suggested that the method combining the Data Quality Objectives (DQO) process, which is widely adopted in environmental remediation, and the Bayesian inference, is effective. To evaluate the applicability of the method to the 1F waste, we tried to apply the method by setting the objective to classify rubble, which has large individual differences and diverse properties. In this study, we calculated the sample size required to determine the classification by difference of contamination by alpha nuclides for the rubble collected from the reactor buildings. We report on analysis planning for the rubble from the reactor buildings using the DQO process and the Bayesian inference.

A Study of statistical planning method for analysis consistent with the characteristics of the Fukushima Daiichi NPS Wastes, 2; Calculation of the optimal sample size using the Bayesian inference

Horita, Takuma; Akimoto, Maya; Nagai, Anna; Oki, Keiichi; Pyke, C.*; Hiller, P.*; Koma, Yoshikazu

no journal, , 

In order to streamline the characterization of radioactive wastes generated by the decommissioning of the Fukushima Daiichi Nuclear Power Station (1F) for the treatment and disposal, we are considering an efficient planning method for analysis. The planning method is combined the Data Quality Objectives Process (DQO process), which defines the quality control method for collecting environmental analysis data, and the Bayesian inference, which is a statistical method. Calculations using the Bayesian inference allow us to probabilistically evaluate the sample size required to obtain the desired results. In other words, unlike conventional tests conducted with frequency statistics, the sample size can be obtained along with the probability, and thus the sample size can be flexibly planned based on the probability. In this presentation, we will report on a method for calculating the sample size for two purposes: (1) comparison with the reference value for disposal, and (2) population classification according to disposal properties.