Physical protection corrective action program activities in JAEA

Shibata, Ryodai; Amano, Tsukasa; Yamada, Hiroyuki; Miyaji, Noriko; Nakamura, Hironobu

Dai-44-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2023/11

In April 2020, JAEA has been introduced Physical Protection Corrective Action Program (PPCAP) with full-scale. It was needed to introduce unified operation for six sites with different business scales, and headquarters developed the common guideline. There was an impression that physical protection activities were carried out by a limited number of employees. Therefore, a problem was to root and activate PPCAP activities among all employees in order to make them effective. Five activities were implemented to solve this problem. As a result, more than 3,700 condition reports (CR) have been collected for 4 years. This paper reports on the activities related to the PPCAP that have been implemented at JAEA.

Interaction of millisecond kW-class laser pulses with metals and metal oxides; Fundamentals of processing

Daido, Hiroyuki*; Yamada, Tomonori

ILT-APR-34; ILT 2023 Nempo (Internet), p.1 - 5, 2023/07

The decommissioning of Fukushima and the contribution to reconstruction have become national issues. The authors participated in the "Analysis of fine particles generated by laser processing and development of nuclide identification method" (represented by Professor Shuichi Hasegawa of the University of Tokyo), which was adopted as one of the JAEA's publicly solicited projects for this purpose, from FY 2018 to FY 2021 as a subcontractor, The authors conducted research on the observation, evaluation and analysis of the interaction between lasers and various laser-irradiated targets. This report outlines the results of the research in which the authors took part. In the experiments, laser irradiation was carried out on test specimens set up in an irradiation chamber, and shadowgraphs were taken using a high-speed camera and a He-Ne laser. As an example of the experimental results, shadowgraphs of metal (stainless steel) and metal oxide (zirconia), irradiation traces after laser irradiation, and the relationship between laser irradiation power and jet mass are shown, and the interaction between the laser and the metal or metal oxide is discussed. The results will not only contribute to the decommissioning technology of the Fukushima Daiichi NPP, but also to laser processing technology and laser interaction research.

Study of non-destructive slow beam extraction method in particle accelerator

Nagayama, Shota; Harada, Hiroyuki; Shimogawa, Tetsushi*; Yamada, Ippei; Chimura, Motoki; Yamamoto, Kazami; Kinsho, Michikazu

Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.503 - 507, 2023/01

https://www.pasj.jp/web_publish/pasj2022/proceedings/PDF/WEP0/WEP002.pdf

Synchrotron accelerators realize physics experiments and radiation cancer treatment using the slow extraction technique, in which beams are stored in the ring and gradually delivered. We have devised and are currently developing a "non-destructive electrostatic septum" based on a new method, which in principle cannot be solved by conventional methods and is a cause of equipment failure and output limitation. It is ideal to generate a force distribution similar to a staircase function with discontinuous gaps at the boundary. In this presentation, we will show the calculation method for optimizing the electrode and wire configuration to generate a Lorentz force with a distribution similar to a staircase function in vacuum, and the calculation results of the beam breakup due to the generated Lorentz force. The compact proof-of-principle machine developed for the ongoing demonstration of this method will also be introduced.

Neutron reflectivity study on the suppression of interfacial water accumulation between a polypropylene thin film and Si substrate using a silane-coupling agent

Shimokita, Keisuke*; Yamamoto, Katsuhiro*; Miyata, Noboru*; Arima-Osonoi, Hiroshi*; Nakanishi, Yohei*; Takenaka, Mikihito*; Shibata, Motoki*; Yamada, Norifumi*; Seto, Hideki*; Aoki, Hiroyuki; et al.

Langmuir, 38(41), p.12457 - 12465, 2022/10

https://doi.org/10.1021/acs.langmuir.2c01599

Development of a laser-driven ultrasonic technology for characterizations of heated and aged concrete samples

Yamada, Tomonori; Daido, Hiroyuki*; Shibata, Takuya

Journal of Nuclear Science and Technology, 59(5), p.614 - 628, 2022/05

https://doi.org/10.1080/00223131.2021.1996295

Neutron reflectometry-based structural analysis of an aligning agent additive for the alignment of nematic liquid crystals on solid substrates

Nemoto, Fumiya*; Yamada, Norifumi*; Hino, Masahiro*; Aoki, Hiroyuki; Seto, Hideki*

Soft Matter, 18(3), p.545 - 553, 2022/01

https://doi.org/10.1039/D1SM01355F

Test methods for robots for nuclear emergency response and decommissioning; Tests for moving performances of robots (JAEA-TM-0004 and JAEA-TM-0005)

Kawabata, Kuniaki; Yamada, Taichi; Abe, Hiroyuki*

JAEA-Technology 2021-021, 30 Pages, 2021/11

JAEA-Technology-2021-021.pdf:2.55MB

This report describes the test procedures for performance evaluation of remotely operated robot utilized for nuclear emergency responses and decommissioning that provide to compare among the robot's performances quantitatively and relatively. After the accident at Fukushima Daiichi Nuclear Power Station of the Tokyo Electric Power Company Holdings Inc. (FDNPS) occurred, remotely operated robots have been deployed and utilized in the response tasks. Such post-accident work experiences and lessons learned are very valuable for developing the robots in the future. Therefore, we were motivated to develop the test methods for performance evaluation of the robot by referring with such experiences and lessons. In recent decommissioning tasks, reconnaissance on the distribution and status of nuclear fuel debris inside the Primary Containment Vessel (PCV) have been carried out. The insertion and deployment of robots into PCV were carried out through a penetration pipe with small diameter to prevent the scattering of radioactive materials. According to the authors' survey on such works have carried out in Units 1 and 2 of FDNPS, in order to carry out the reconnaissance work by the robot deployed into the PCV, it was clarified that the robots are required to run freely on the floor located below the exit of the penetration pipe and run freely on the inclined surface located below the exit of the pipe. This document describes two test procedures for performance evaluation of the robot connected with the cable such as running on the floor after being deployed through a penetration pipe and running on the inclined surface after being deployed through a penetration pipe. Typical course layout and the demonstration of test running are also illustrated for the references.

Initiatives to address the lifetime improvement of HBC stripper foil for 3GeV synchrotron of J-PARC

Yoshimoto, Masahiro; Nakanoya, Takamitsu; Yamazaki, Yoshio; Saha, P. K.; Kinsho, Michikazu; Yamamoto, Shunya*; Okazaki, Hiroyuki*; Taguchi, Tomitsugu*; Yamada, Naoto*; Yamagata, Ryohei*

Proceedings of 18th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.850 - 854, 2021/10

no abstracts in English

Generation of particles and fragments by quasicontinuous wave fiber laser irradiation of stainless steel, alumina, and concrete materials

Daido, Hiroyuki*; Yamada, Tomonori; Furukawa, Hiroyuki*; Ito, Chikara; Miyabe, Masabumi; Shibata, Takuya; Hasegawa, Shuichi*

Journal of Laser Applications, 33(1), p.012001_1 -  012001_16, 2021/02

https://doi.org/10.2351/7.0000190

Test methods for robots for nuclear emergency response and decommissioning; Tests for running performances of robots (JAEA-TM-0001, JAEA-TM-0002 and JAEA-TM-0003)

Kawabata, Kuniaki; Yamada, Taichi; Abe, Hiroyuki*

JAEA-Technology 2020-015, 37 Pages, 2020/11

JAEA-Technology-2020-015.pdf:3.81MB

This report describes the test procedures for evaluating running performances of remotely operated robot utilized for nuclear emergency responses and decommissioning. After the accident at Fukushima Daiichi Nuclear Power Station of the Tokyo Electric Power Company Holdings Inc. (FDNPS) occurred, remotely operated robots have been deployed and utilized in the response tasks. Such post-accident work experience and lessons learned are very valuable for developing the robots in the future. Therefore, we were motivated to develop the test methods for performance evaluation of the robot by referring with such experiences and lessons. Based on our examinations, in order to execute the response and decommissioning tasks, the robots are required to run through the space without enough margin and avoiding collisions, to move on stairs while avoiding tumbling or falling down and to drag a cable while avoiding problems caused by the cable entwining around objects. This report describes three test procedures for quantitatively evaluating the performances which are for running narrow passage, climbing up/down on the stairs and running with dragging the cable. Typical course layout and the demonstration of test running are also illustrated for the references.