Refresh project of virtual reality system for education and training

Numata, Masaaki; Ogura, Yuichi*; Nakagawa, Yosuke; Inoue, Naoko

Dai-41-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 3 Pages, 2020/11

JAEA/ISCN is actively using a virtual reality (VR) system for training in nuclear non-proliferation safeguards and nuclear security. The VR system allows participants to experience the environment of a nuclear power plant and a research reactor in a cyber space. It is beneficial for the participants who have never been in a nuclear power plant to see how they are even virtually, in order to learn their physical protection system. Workstations of OS for VR use Windows7 and the warrantee protection period expired in March 2020. For that reason, it was decided to renew those workstations over 2019-2020. This paper will describe its planning called "Refresh Project", which aims to minimize impacts on training and visitors, as well as first year achievement.

Investigation of countermeasure against local temperature rise in vessel cooling system in loss of core cooling test without nuclear heating

Ono, Masato; Shimizu, Atsushi; Kondo, Makoto; Shimazaki, Yosuke; Shinohara, Masanori; Tochio, Daisuke; Iigaki, Kazuhiko; Nakagawa, Shigeaki; Takada, Shoji; Sawa, Kazuhiro

Journal of Nuclear Engineering and Radiation Science, 2(4), p.044502_1 - 044502_4, 2016/10

https://doi.org/10.1115/1.4032478

In the loss of forced core cooling test using High Temperature engineering Test Reactor (HTTR), the forced cooling of reactor core is stopped without inserting control rods into the core and cooling by Vessel Cooling System (VCS) to verify safety evaluation codes to investigate the inherent safety of HTGR be secured by natural phenomena to make it possible to design a severe accident free reactor. The VCS passively removes the retained residual heat and the decay heat from the core via the reactor pressure vessel by natural convection and thermal radiation. In the test, the local temperature was supposed to exceed the limit from the viewpoint of long-term use at the uncovered water cooling tube by thermal reflectors in the VCS, although the safety of reactor is kept. Through a cold test, which was carried out by non-nuclear heat input from gas circulators with stopping water flow in the VCS, the local higher temperature position was specified although the temperature was sufficiently lower than the maximum allowable working temperature, and natural circulation of water had insufficient cooling effect on the temperature of water cooling tube below 1C. Then, a new safe and secured procedure for the loss of forced core cooling test was established, which will be carried out soon after the restart of HTTR.

Reconfirmation of facilities/instruments integrity by cold test of HTTR

Ono, Masato; Shinohara, Masanori; Iigaki, Kazuhiko; Tochio, Daisuke; Nakagawa, Shigeaki; Shimazaki, Yosuke

JAEA-Technology 2013-042, 45 Pages, 2014/01

JAEA-Technology-2013-042.pdf:10.51MB

In HTTR, it has passed about two years since the last performance confirmation test. During two years, the integrity of active equipment, leakage efficiency of coolant pressure boundary of piping and vessel and control system performance due to influence of damage and deterioration by earthquake and aging were not confirmed. To confirm them, the cold test by using HTTR was conducted and the system performances such as above mentioned items were evaluated by comparing with the plant data obtained by the past cold test. In the result, no abnormity was found in all the data in the cooling system of HTTR, and it was confirmed that the integrity of facilities and instruments of HTTR was maintained in good condition.

Pre-investigation of thermal load fluctuation test of the heat utilization system using the HTTR

Tochio, Daisuke; Saito, Kenji; Shimazaki, Yosuke; Nakagawa, Shigeaki

JAEA-Technology 2011-018, 43 Pages, 2011/06

JAEA-Technology-2011-018.pdf:2.44MB

In the HTTR, safety demonstration tests are performed after the first criticality achieved in 1998. Thermal load fluctuation test of the heat utilization system using the HTTR are planned in order to demonstrate reactor system stability in the case of thermal load fluctuation of the heat utilization system in HTGR hydrogen production system. So pre-investigations of thermal-load fluctuation tests using the HTTR are conducted to investigate the available test condition. As the result, it is confirmed that the ACL fan stopping tests can be conducted under a condition and provide the data needed to verify the plant dynamics simulation code for future HTGR.

Preliminary study on HTTR tests for development of commercial HTGRs

Goto, Minoru; Takamatsu, Kuniyoshi; Nakagawa, Shigeaki; Ueta, Shohei; Hamamoto, Shimpei; Ohashi, Hirofumi; Furusawa, Takayuki; Saito, Kenji; Shimazaki, Yosuke; Nishihara, Tetsuo

JAEA-Technology 2009-053, 48 Pages, 2009/10

JAEA-Technology-2009-053.pdf:3.41MB

Preliminary studies on the HTTR (High Temperature engineering Test Reactor) tests were conducted to obtain characteristics and demonstration data which were required to develop commercial HTGRs (high temperature gas-cooled reactors). The tests proposed in this study are as follows: nuclear heat supply characteristics tests, burned core tests, reactivity insertion tests, safety demonstration tests, fuel characteristics tests, annular core tests, fuel failure tests, tritium measurement tests, and health confirmation tests of high temperature equipments. Requirements for a development of commercial HTGRs and confirmation methods of the requirements by the HTTR tests were summarized. Preliminary analyses were performed for the burned core test and the safety demonstration test to obtain prediction data, which is compared with experimental data. Additionally, a feasibility analysis was performed on four types annular cores, which is composed of the HTTR's fresh fuels, from the point of view of shutdown margin and excess reactivity.

Pulse radiolysis study on free radical scavenger edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one)

Lin, M.; Katsumura, Yosuke; Hata, Kuniki; Muroya, Yusa*; Nakagawa, Keiichi*

Journal of Photochemistry and Photobiology B; Biology, 89(1), p.36 - 43, 2007/11

https://doi.org/10.1016/j.jphotobiol.2007.08.001

A Study on antioxidative capacity of edaravone and its derivatives by pulse radiolysis

Hata, Kuniki; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Kudo, Hisaaki*; Nakagawa, Keiichi*; Nakagawa, Hidehiko*

no journal, , 

no abstracts in English

A Study on antioxidative property of edaravone derivatives by pulse radiolysis

Hata, Kuniki; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Fu, H.*; Kudo, Hisaaki*; Nakagawa, Keiichi*; Nakagawa, Hidehiko*

no journal, , 

The reactivity of edaravone with some oxidative radicals (OH, N, Br, SO, CClOO) has been measured by pulse radiolysis. The reaction product of edaravone with OH was different from those with other radicals. The rate constants of edaravone derivatives with OH have also been determined by both direct measurement and a competition method using CO and DMPO as competitors.

A Study on the reactivity of Edaravone with oxidative radicals by pulse radiolysis

Hata, Kuniki; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Kudo, Hisaaki*; Nakagawa, Keiichi*; Nakagawa, Hidehiko*

no journal, , 

Edaravone, 3-methyl-1-phenyl-2-pyrazolin-5-one, is a newly developed free radical scavenger that has been approved in Japan as a neuroprotective drug since 2001. In the present work, the transient intermediates and the reactivity of edaravone towards OH, N, Br, SO, and CClO are investigated by pulse radiolysis techniques. The oxidation of edaravone by N, Br, SO, and CClO results in an absorption band with = 345 nm ( = 2600 Mcm), which is assigned to the edaravone radical formed by H-abstraction or electron transfer. However, the transient species produced by the reaction of edaravone with OH radical shows an absorption band with = 320 nm ( = 4900 Mcm). Accordingly, the main transient species by the reaction of edaravone with OH radical in the absence of O is attributed to OH-adducts. The rate constants of edaravone reacting with OH, N, SO, and CClO are estimated to be 8.510, 5.410, 6.010, and 5.110 Ms, respectively.

A Study on the reactivity of edaravone derivatives by pulse radiolysis

Hata, Kuniki; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Fu, H.*; Kudo, Hisaaki*; Nakagawa, Keiichi*; Nakagawa, Hidehiko*

no journal, , 

no abstracts in English