JAPAN ATOMIC INDUSTRIAL FORUM, INC.

for Japanese

ATOMS in JAPAN

31 May, 2019

NRA Orders Kansai EP to Backfit Takahama and Other NPPs Based on New Volcano Impact Information

At a regular meeting on May 29, Japan’s Nuclear Regulation Authority (NRA), based on the latest assessment of the impact from an eruption of Mt. Daisen in Tottori Prefecture, decided to order the Kansai Electric Power Co. (Kansai EP) to file applications for permissions to change reactor installations for its Takahama, Ohi and Mihama Nuclear Power Plants by the end of the year.

Commissioner Ishiwatari (second from left) investigates volcanic ash distribution in October 2018 (photo provided by NRA)

The Takahama-1 through -4, Ohi-3 and -4 and Mihama-3 NPPs had already all cleared compatibility examinations with the new regulatory standards.

However, the most recent analysis of a potential eruption of Mt. Daisen has predicted some 11 cubic kilometers of deposited ash in the Daisen-Namatake Tephra (the place being investigated in Kyoto City), more than previously thought. Accordingly, the so-called “backfit” will be undertaken to confirm compatibility with the new knowledge.

Given, however, that Mt. Daisen is not an active volcano—meaning that there is no imminent eruption—the NRA does not consider it necessary for the power company to suspend the operations of the reactors immediately.

Based on the aforementioned analysis of volcanic ash at the Daisen-Namatake Tephra, the NRA had ordered Kansai-EP in December 2018 to submit reports on its NPP sites. The company then calculated ash layers within the precincts of the Takahama, Ohi and Mihama sites, putting the maximum thickness at 21.9cm. Prior approvals of compatibility under the new regulatory standards had been based on a maximum thickness of 10cm.

Thus, the NRA, having found the units to be incompatible, rendered its decision accordingly.

At a post-meeting press conference, NRA Chairman Toyoshi Fuketa explained the decision, saying, “When new information on natural phenomena is acquired and a threat is found to be more severe than previously assumed, designs must be changed in accordance with that knowledge.”

He emphasized that the NRA’s approach to backfitting was guided by lessons learned from the accident at the Fukushima Daiichi NPPs in March 2011.

Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

SNS facebooktwitter

NPPs Map

Video

“The current situation at Fukushima Daiichi NPS” -From 3.11 toward the future- (ver, July 2019)

8 July, 2019
“The current situation at Fukushima Daiichi NPS” -From 3.11 toward the future- (ver, July 2019)09:17

Recent News

13 December, 2019
NRA Approves Decommissioning Plans for Kansai EP’s Ohi-1 and-2
12 December, 2019
JAEA Holds International Forum on Peaceful Use of Nuclear Energy, Nuclear Non-Proliferation and Nuclear Security
29 November, 2019
NRA Issues Draft Review Report: Onagawa-2 Meets New Regulatory Standards
28 November, 2019
RIKEN Unveils Transportable Compact Neutron Source System
27 November, 2019
JAIF Releases Results of Fact-Finding Survey of Japanese Nuclear Industry for Fiscal 2018
26 November, 2019
Hitachi Receives Order from Mayo Clinic to Build First Carbon Ion Treatment System in North America
25 November, 2019
Keidanren: Japan’s Commitment to Low-Carbon Society Shows NPP Restarts Helped Reduce CO2 Emissions in Fiscal 2018
21 November, 2019
TEPCO Announces Timeline for Storage and Disposal of Treated Contaminated Water at Fukushima Daiichi
15 November, 2019
JAEA Holds Public Meeting, Discusses Future Vision, Fukushima Reconstruction and Revitalization
15 November, 2019
IAEA/RCA Symposium: Cooperating with Developing Countries Through Nuclear Science and Technology
▲TOP