Analysis of work activities involved in clearance verification process of decommissioning Fugen Nuclear Power Plant

Yamamoto, Kosuke; Yanagihara, Satoshi*

Journal of Nuclear Science and Technology, 59(12), p.1527 - 1535, 2022/12

https://doi.org/10.1080/00223131.2022.2071350

A series of work activities involved in clearance verification process was analyzed from the viewpoint of work efficiency at Fugen. As a result, decontamination required the most manpower expenditure. In addition, most of clearance candidate materials were very low contamination before the decontamination work. The analysis indicates that it will be effective for these lower radioactivity parts to reduce effort of decontamination activity or to skip the decontamination scenario considering that radioactivity was enough low. In addition, sample monitoring is possible scenario depending on the degree of contamination rather than to monitor all unit for clearance verification. When the manpower is evaluated based on the actual results of Fugen in consideration of these conditions, the clearance verification process could make the efficiency less than 37% in case of Fugen decommissioning.

Document collection of the 37th Technical Special Committee on Fugen Decommissioning

Nakamura, Yasuyuki; Koda, Yuya; Yamamoto, Kosuke; Soejima, Goro; Iguchi, Yukihiro

JAEA-Review 2020-002, 40 Pages, 2020/05

JAEA-Review-2020-002.pdf:8.78MB

Fugen Decommissioning Engineering Center, in planning and carrying out our decommissioning technical development, has been establishing "Technical special committee on Fugen decommissioning" which consists of the members well-informed, aiming to make good use of Fugen as a place for technological development which is opened inside and outside the country, as the central point in the energy research and development base making project of Fukui prefecture, and to utilize the outcome in our decommissioning to the technical development effectively. This report compiles presentation materials "The Current Situation of Fugen Decommissioning", "Development of Dismantling Mon-hours Estimated system by Achieved Data in Fugen", "Future Plan Based on the Operational Status of Clearance System" and "The Result and Future Plan of the Sampling work from Core Internal of Fugen", presented in the 37th Technical special committee on Fugen decommissioning which was held on December 2, 2019.

Working in the third year of Fugen and attempting to take qualification examinations

Yamamoto, Kosuke

no journal, , 

no abstracts in English

Current status of clearance verification in Fugen

Yamamoto, Kosuke

no journal, , 

no abstracts in English

Special training on decommissioning

Uta, Masato; Nakayama, Tamotsu; Ishiyama, Masahiro; Kadowaki, Haruhiko; Yamamoto, Kosuke; Hatakeyama, Takumi

no journal, , 

no abstracts in English

放射能評価方法、放射能評価プログラム及び放射能評価装置

山本 耕輔; 川越 慎司; 東浦 則和; 水井 宏之

not registered

JP, 2020-055379  Patent licensing information  Patent publication (In Japanese)

【課題】評価の保守性の観点から放射能濃度を適切に評価することができる放射能評価方法を提供する。 【解決手段】放射能評価方法は、測定対象物の放射能濃度を算定する放射能濃度算定工程(S4)と、放射能濃度の相対誤差σ'Dを算定する誤差算定工程(S5)と、放射能濃度の相対誤差σ'Dに基づく不確定性を考慮して放射能濃度を評価する評価工程(S6)とを含み、誤差算定工程(S5)は、グロス計数率の測定プロセスに起因する複数のグロス誤差を重畳してグロス計数率の誤差σCGを算定するグロス誤差算定工程(S51)と、測定BG計数率の測定プロセス及び推定BG計数率の推定プロセスに起因する複数のBG誤差を重畳して推定BG計数率の誤差σCBGを算定するBG誤差算定工程(S52)と、グロス計数率の誤差σCGと、推定BG計数率の誤差σCBGとに基づいて、正味計数率の相対誤差σ'CNを算定する正味計数率誤差工程(S53)とを含む。

放射能評価方法、放射能評価プログラム及び放射能評価装置

山本 耕輔; 川越 慎司; 東浦 則和; 水井 宏之

not registered

JP, 2020-057662  Patent licensing information  Patent publication (In Japanese)

【課題】評価の保守性の観点から放射能特性を適切に評価することができる放射能評価方法を提供する。 【解決手段】放射能評価方法は、グロス計数率CGが測定される前の第1のBG計数率CBG1と、グロス計数率CGが測定された後の第2のBG計数率CBG2との差分であるBG計数率変動量ΔCBGを算定するBG変動量算定工程(S4)と、第1のBG計数率CBG1及び第2のBG計数率CBG2の測定に含まれる複数の誤差要因に起因する複数のBG誤差を重畳することによりBG計数率変動量ΔCBGの誤差σΔCBGを算定するBG変動誤差算定工程(S5)と、BG計数率変動量ΔCBGの誤差σΔCBGに基づいて、BG計数率変動量ΔCBGとして許容されるBG計数率許容変動量ΔCBGLを算定し、当該BG計数率許容変動量ΔCBGLを用いてBG計数率変動量ΔCBGを評価して、測定作業の有効性を判定する有効性判定工程(S6)とを含む。