Contribution by incorporation of laser technology and robotics technology for Fukushima Daiichi Nuclear Power Plants decommissioning

Kawatsuma, Shinji

Reza Kenkyu, 45(7), p.413 - 417, 2017/07

https://doi.org/10.2184/lsj.45.7_413

Inside and surrounding area of reactor buildings of Fukushima Daiichi Nuclear Power Plants became high radiation condition because of radioactive materials release by the accidents caused by earthquake of Pacific coast on eastern and northern Japan. In the stage of emergency response to the accidents, more than 20 robots had been deployed, and some of them had equipped with laser technologies like as laser range finder. In the following decommissioning stage of the plans, operations under higher radiation condition will be required, so that varied laser technologies will be needed to fuse with robot technologies. Laser checker laser analysis would be expected besides laser range finder. However those technologies will be deployed under higher radiation condition, so radiation hardening and control stabilizing should be solved.

Unitization for portability of emergency response surveillance robot system; Experiences and lessons learned from the deployment of the JAEA-3 emergency response robot at the Fukushima Daiichi Nuclear Power Plants

Kawatsuma, Shinji; Mimura, Ryuji; Asama, Hajime*

ROBOMECH Journal (Internet), 4, p.6_1 - 6_7, 2017/02

https://doi.org/10.1186/s40648-017-0073-7

It was cleared that portability of emergency response reconnaissance robot had been very important. So, RESQ-A robots, which had been developed by Japan Atomic Energy Research Institute (present Japan Atomic Energy Agency), had been considered from the view point of portability. After Fukushima Daiichi NPPs' accidents occurred, JAEA had modified a RESQ-A robot to JAEA-3 robot in order to meet the anticipated situation of the accidents. However, actual situation was beyond the anticipated situation, and additional modification was required. The actual confused situation was many rubble were scattered and temporary cables and hoses were constructed in the reactor buildings, so that reconnaissance robots should be conveyed by operators through limited route, should be reassembled in short time and should be able to remove cable and tiers for reduce the operators' exposure dose during maintenance. JAEA modified again JAEA-3 robot system, with cooperation of operators from Fukushima Daiichi NPPs. It was lesson learned that emergency response reconnaissance robot needed to be unitized for portability, and "Unitization Policy for emergency response reconnaissance robot" was developed.

Radiation tolerance and management method of Robots and unmanned heavy construction machines using semiconductors on the shelf

Kawatsuma, Shinji; Asama, Hajime*

Nihon Robotto Gakkai-Shi, 34(8), p.552 - 557, 2016/10

https://doi.org/10.7210/jrsj.34.552

There was not a guideline available for researchers, developers or users for robots or heavy construction machines on the evaluation of radiation tolerance and management method of robots and heavy construction machines using semiconductors, like as CPUs on the shelf, under radiation condition, when Fukushima Daiichi NPPs accidents occurred on March 11th, 2011. The evaluation and the management method became necessary, in order to deploy robots like as QUINCE developing for big city accidents or unmanned heavy construction machines for landside disaster. According to "radiation tolerance data base on parts or materials" developed in 1980's to 1990's by Japan Atomic Energy Agency (JAEA), a guideline, for robots and unmanned heavy construction machines, was tentatively developed.

Basic decontamination methodology of robots and robot control vehicles

Kawatsuma, Shinji; Asama, Hajime*

Proceedings of American Nuclear Society 2014 Annual Meeting; Embedded Topical Meeting on Decommissioning and Remote Systems (D&RS 2014) (DVD-ROM), p.19 - 21, 2014/06

Contamination survey and decontamination methodology became to be needed, because several robots could not have been decontaminated enough for direct maintenance even after water spray decontamination when robots and robot control vehicles were contaminated during deployment for emergency response to Fukushima Daiichi NPPs accidents. "Basic Decontamination Methodology" was established based on confirmation of water spray effectiveness, specification of parts difficult to decontaminate by water spray and identifying of effective decontamination method for the parts, after investigations of the robots and robot control vehicles deployed for emergency response to Fukushima Daiichi NPPs accidents.

Survey report of regulation trend relate to uranium bearing waste in an international organization and foreign countries

Ouchi, Masaru; Takebe, Shinichi; Kawatsuma, Shinji; Fukushima, Tadashi*

JAEA-Review 2012-019, 186 Pages, 2013/02

JAEA-Review-2012-019.pdf:11.86MB

We have reviewed information about justification for establishing uranium bearing waste acceptance for near surface disposal (trench and concrete pit disposals) in foreign countries, to intend to discuss clearance level and disposal of uranium bearing waste in Japan. Most of EU countries have adopted the unconditional clearance level 1 Bq/g described in EU Guidance RP 122 Part 1 and IAEA Safety Guide RS-G-1.7 for uranium wastes. And in the case of special landfill burial, the conditional clearance level about 10 Bq/g (equivalent to exemption level) has been adopted in Germany, Sweden and UK.

Basic of radiation and contamination control of construction heavy machines

Kawatsuma, Shinji

Kensetsu No Seko Kikaku, (749), p.67 - 71, 2012/07

Accidents at Fukushima Nuclear Power Station occurred on March 11th, 2011, and many construction heavy machines have been deployed. Maintenance task is very important for keeping those machines normal. However, it is subject that those machines are contaminated by radioactive materials. This paper overhaules affects to human by radiation as "basic of radiation" and show that the affects, by less than 100 mSv radiation, is little. Also, this paper introduce practical example of contamination control of construction heavy machines, in order to reduce radiation exposure to workers for maintenance, and overhaules methods of contamination control.

Radiological emergency response to Fukushima Daiichi Accident; Teleoperation & robotics of JAEA

Fukushima, Mineo; Kawatsuma, Shinji; Okada, Takashi

Proceedings of American Nuclear Society Embedded Topical on Decommissioning, Decontamination and Reutilization and Technology Expo (DD&R 2012) (DVD-ROM), p.67 - 68, 2012/06

The accident on Fukushima Daiichi Nuclear Power Plant has been occurred by the TSUNAMI that generated form Great East Japan Earthquake happened in 11th March 2011. Just after the earthquake, JAEA is assisting activities concerning the accident of the Fukushima No.1 Nuclear Power Station including teleoperation, decontamination and radiation monitoring in the site. JAEA had already developed some robotics, RESQ series, for radiological emergency response in 2001, after JCO criticality accidents occurred. However, they could not work for the NPP because of lack of maintenance. According to the situation and condition of the FUKUSHIMA-DAIICHI accident, JAEA has modified above mentioned robotics and prepared supporting equipments like as Robotics control vehicles. JAEA has provided Robotics and Robotics Control vehicles to TEPCO and is continuously supporting Tokyo Electric Company for plant restoration.

JAEA robotics emergency response to Fukushima-Daiichi accident; Summary and lessons learned

Kawatsuma, Shinji

RANDEC Nyusu, (90), p.11 - 13, 2012/02

http://www.randec.or.jp/publish/documents/RANDEC%20NEWS/RANDEC%20NEWS_90.pdf#page=13

no abstracts in English

Activities and lesson learned on nuclear disaster robots of JAEA in the disaster at Fukushima Daiichi Nuclear Power Station

Kawatsuma, Shinji

Science Academy of Tsukuba, (20), p.15 - 18, 2011/10

http://www.science-academy.jp/publications/pdf/sat_journal_20.pdf

no abstracts in English

Uranium distribution in the environment and its contribution to environmental radioactivity

Sato, Kazuhiko; Ishibashi, Makoto*; Kawatsuma, Shinji

Dekomisshoningu Giho, (38), p.2 - 10, 2008/11

http://www.randec.or.jp/publish/documents/gihou/Decommissioning%20gihou_38.pdf

Clearance of materials and disposal of radioactive waste generated from uranium utilizing facilities which include uranium conversion and enrichment facilities, and fuel fabrication facility among the nuclear fuel cycle has been discussed in Japan. These materials are supposed to be contaminated with long-lived natural nuclide, i.e. uranium. Uranium is widely distributed among the environment, e.g. soil, rock, river-water, groundwater and so on. Furthermore, uranium is also contained in some building materials and consumer goods. Literature survey about distribution of uranium in the environment and measurement of uranium concentration in some materials were carried out. As a result, it is revealed that range of U-238 activities in soils in Japan is from 0.001 Bq/g to about 1 Bq/g. Addition to that, the range of building materials is overlapped by that of soils, while some consumer goods showed relatively high activities. Futermore, dose contribution of uranium series nuclides to the environmental radiation dose were discussed. It is suggested that, sum of environmental radiation dose in Japan is about 1.5 mSv/yr and dose contribution of uranium series nuclides is about 0.8 mSv/yr.