Operator's contribution on the improvement of RII scheme against the process operation at PCDF

Nakamura, Hironobu; Shimizu, Yasuyuki; Makino, Risa; Mukai, Yasunobu; Ishiyama, Koichi; Kurita, Tsutomu; Ikeda, Atsushi*; Yamaguchi, Katsuhiro*

Proceedings of INMM 57th Annual Meeting (Internet), 9 Pages, 2016/07

Regarding the Integrated Safeguards (IS) in Japan, the implementation of IS has been started on September 2004, and the concept has been introduced to the JNC-1 facilities since August 2008. Then, random interim inspection with short notice and reducing person-days of inspection (PDI) was introduced instead of traditional scheduled IIV in order to improve deterrence of the nuclear material diversion with timeliness goal. And it was agreed that it should be evaluated and reviewed because RII was designed when inter-campaign. In JAEA, we decided to restart PCDF campaign to reduce potential safety risks of reprocessing facilities. To adopt the RII scheme to the process operation in campaign, JAEA proposed a new scheme to JSGO and IAEA without increasing PDI and reducing detection probability. As a result of the discussion, it was agreed and successfully introduced since March 2014. The new scheme for PCDF consists of scheduled inspection (fixed-day RII), reduction of estimated material for the verification, implementation of remote monitoring with data provision, improvement of operational status check list, introduction of NRTA and MC&A data declaration with timeliness. Though the operator's workloads for information provision were increased, we could manage to balance IS requirement with implementation of our operation successfully. This contribution was helped to safeguards implementation and our operation for 2 years.

Application of wireless LAN technology to remote monitoring for inspection equipment

Ishiyama, Koichi; Kimura, Takashi; Miura, Yasushi; Yamaguchi, Katsuhiro*; Kabuki, Toshihide*

Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-32-Kai Nenji Taikai Rombunshu (Internet), 8 Pages, 2011/11

To support inspections under an Integrated Safeguards regime into Tokai Reprocessing Plant (TRP), the IAEA suggested making use of Remote Monitoring (RM) capabilities to the inspection equipment (surveillance camera and NDA systems) installed in the spent fuel storage area at TRP. Since the spent fuel storage area in TRP did not have pre-prepared cabling infrastructure for data transmission, the option of wireless LAN was chosen over the telephone line due to its lower installation costs. Feasibility studies and tests were performed by TRP on communication and particularly on long-term continuous communication using wireless LAN equipment (AP: Access Point) and an external antenna for introducing wireless LAN technology to RM. As a result it was recognized that wireless LAN has enough ability to communicate for long periods of time and consequently the IAEA installed AP and an external antenna to each inspection equipment and the wireless LAN technology was applied for RM.

Sampling and treatment of rock cores and groundwater under reducing environments of deep underground

Ebashi, Katsuhiro; Yamaguchi, Tetsuji; Tanaka, Tadao; Araki, Kunio*; Saito, Masao*

JAERI-Conf 2005-007, p.242 - 247, 2005/08

https://jopss.jaea.go.jp/pdfdata/JAERI-Conf-2005-007.pdf

no abstracts in English

Horonobe Underground Research Laboratory Project Investigation Program for the 2005 Fiscal Year (2005/2006)

Hama, Katsuhiro; Seya, Masami; Yamaguchi, Takehiro

JNC TN5510 2005-002, 29 Pages, 2005/05

JNC-TN5510-2005-002.pdf:8.27MB

The Horonobe Underground Research Laboratory Project is planned to extend over 20 years. Investigations will be conducted in three phases, namely from the surface (Phase 1), during construction of the underground facility (Phase 2) and in the underground facility itself (Phase 3). The 2005 fiscal year is the sixth (and final) year of the Phase 1 investigations and the first year of the Phase 2 investigations.Geophysical, geological, surface hydrogeological and borehole investigations are being carried out in order to develop techniques for exploring the geological environment. Based on the acquired data, geoscientific models are being constructed, revised and verified.As part of the development of techniques for monitoring the geological environment, long-term monitoring of groundwater pressures is ongoing in a borehole equipped in a previous investigation phase. Long-term monitoring systems are also being installed in the remaining boreholes at the site and measurements are ongoing. A remotely operated monitoring system (ACROSS) is also being installed and tested. Studies on the long-term stability of the geological environment include monitoring with seismographs, GPS and electromagnetic surveys. Engineering techniques for application in the deep underground environment will be developed during construction of the underground facilities. To provide input for detailed planning of the Phase 2 and 3 investigations, laboratory tests are being carried out on tunnel reinforcement materials. With a view to improving their reliability, safety assessment methods are being examined using field and laboratory data. Construction of the surface facilities, initiated in the previous fiscal year, is ongoing and the work on the public exhibition hall has now started. Environmental monitoring is ongoing, as is collaboration with domestic and overseas research institutes.

Horonobe Underground Research Laboratory Project Plan of the Investigation Program for the 2004 Fiscal Year (2004/2005)

Hama, Katsuhiro; Amemiya, Keiji; Yamaguchi, Takehiro

JNC TN5510 2005-001, 23 Pages, 2004/04

JNC-TN5510-2005-001.pdf:7.15MB

The Horonobe Underground Research Laboratory Project is planned to extend over 20 years. Investigations will be conducted in three phases, namely from the surface (Phase 1), during construction of the underground facility (Phase 2) and in the underground facility itself (Phase 3). The 2004 fiscal year is the fifth year of the Phase 1 surface-based investigations.Geophysical, geological, surface hydrogeological and borehole investigations are being carried out in order to develop techniques for exploring the geological environment. Geoscientific models are being constructed, revised and verified based on the acquired data. As part of the development of techniques for monitoring the geological environment, long-term monitoring of groundwater pressures is ongoing in a borehole equipped in a previous investigation phase. Long-term monitoring systems are also being installed in the remaining boreholes at the site and measurements are ongoing. Development of a remotely operated monitoring system (ACROSS) is also continuing. Studies on the long-term stability of the geological environment include monitoring with seismographs, GPS and electromagnetic surveys. With a view to developing engineering techniques for application in the deep underground environment, a basic design for the underground facility has been defined. To provide input for the detailed planning of the Phase 2 and 3 investigations, laboratory tests are being carried out on the transportation and emplacement of the engineered barriers and on tunnel reinforcement materials. With a view to improving their reliability, the appropriateness of safety assessment methods is being examined using field and laboratory data. The design of the surface facilities has been defined and construction work has begun. Environmental monitoring is ongoing, as is collaboration with domestic and overseas research institutes.

Horonobe Underground Research Laboratory Project synthesis of phase 1 investigations 2001-2005; Development of engineering technologies for the deep geological environment

Sanada, Hiroyuki; Hanakawa, Toshiyuki; Ota, Kunio; Abe, Hironobu; Yamaguchi, Takehiro; Kunimaru, Takanori; Ishii, Eiichi; Kurikami, Hiroshi; Tomura, Goji; Shibano, Kazunori; et al.

no journal, , 

no abstracts in English

Operator's experience on random inspection for reprocessing plant at JNC-1 site

Ishiyama, Koichi; Miura, Yasushi; Kimura, Takashi; Hina, Tetsuro; Kodani, Yoshiki; Fukuhara, Junichi; Yamaguchi, Katsuhiro*; Ikeda, Atsushi*; Kabuki, Toshihide*

no journal, , 

Regarding the Integrated Safeguards (IS) for JNC-1 site where includes six facilities of the Reprocessing Center and MOX fuel fabrication facilities and so on, its discussion for application started in June 2004 between the government of Japan and IAEA, its concept was agreed in November 2006, and it has been introduced in August 2008. With IS for JNC-1, for the purpose of improvement of deterrence of the nuclear material diversion, the traditional interim inventory verification (IIV) that had been implemented as scheduled previously has changed to random interim inspection with short notice (RII.)The Tokai Reprocessing Center consists of 2 facilities; TRP and PCDF, and has nuclear materials from the spent fuel to the MOX powder. The IIV needed about 5 person-days for TRP and about 7 person-days for PCDF. It was discussed to make RII procedure that makes it possible to perform such short notice inspection and reduce the person-days by about 2 per a RII. Although it was discussed that what and how frequently information was provided to inspectors in order them to make a plan to implement RIIs. After the introduction of RII, the person-days are decreased even though the operators' work loads for information provision are increased. This paper reports development of the method, experience and expected effectiveness regarding RII to the Tokai Reprocessing Center in the viewpoint of its operator.

Design information questionnaire; Reprocessing example

Nakamura, Hironobu; Kitao, Takahiko; Shimizu, Yasuyuki; Takeda, Seiichi; Yamaguchi, Katsuhiro*

no journal, , 

Based on the DIQ guideline discussed and summarized at the 1st consultancy meeting, since JAEA made an example of DIQ for the reprocessing considering the decommissioning stages as Japan's task, we explain the contents and submit it to IAEA in the 2nd consultancy meeting. Basically, as the information regarding decommissioning stage, date of decommissioned, facility decommissioning plan, nuclear material recovery and removing or rendering inoperable of "essential equipment" with example are additionally described in the DIQ. We hope that this material could be helped to make a reprocessing DIQ (PUREX) in the world.

Measurement of radioisotope production by muon capture

Yamaguchi, Yuji; Harada, Masahide; Kawamura, Naritoshi*; Haga, Katsuhiro

no journal, , 

A negative muon () is captured by a nucleus in many cases when the enters the material. After the nuclear capture, a highly excited (Z-1) nucleus is produced and de-excites via the emission of neutrons and -rays. Because this process can make radioisotpes, the material can be activated. To handle the activated sample safely and properly in the MLF, it is important to estimate its radioactivity accurately. The estimation can be performed using Monte-Carlo simulation code, PHITS. Because the reliability of PHITS results has an impact on radiation safety, benchmark of calculation is required. However, the calculation results cannot be verified due to limited data in terms of Z. It is confirmed that there exist discrepancies between calculation and experimental data. Therefore, comprehensive data of radioisotope production are desired. In this presentation, we report on the preliminary experiment to establish methodology for taking comprehensive data.

Fixed measurement of thermal neutron intensity with gold-foil activation method at the J-PARC spallation neutron source

Harada, Masahide; Oikawa, Kenichi; Tsuchikawa, Yusuke; Yamaguchi, Yuji; Haga, Katsuhiro

no journal, , 

In the spallation neutron source at Materials and Life Science Experimental Facility in J-PARC, a 3-GeV and 1-MW proton beam induces into a mercury target and the neutrons beam is provide to neutron instruments. The target vessels are regularly replaced due to pitting damage. The proton beam power is gradually increased to 800 kW as of June 2022, and the optimum proton beam profile is used depending on the beam power. Based on these observations, fixed-point measurements have been periodically carried out to observe the intensity of the neutrons supplied from the spallation neutron source under the same measurement conditions at NOBORU. In the fixed-point measurements, the activation method with gold foils (15x15x0.1mm) was used to observe the absolute intensity of thermal neutrons with and without cadmium foil. The irradiation time was set to about 10 to 30 minutes in accordance with the proton beam intensity. The gamma-ray from irradiated foil was measured with a germanium detector, and the amount of activation was identified. As a result of the measurement, the thermal neutron intensity was slightly dependent on the proton beam intensity.