Nine years before the 2011 meltdown crisis at the Fukushima No. 1 nuclear power plant, Tokyo Electric Power Co. turned down a request from the government’s nuclear watchdog for it to conduct a simulation of powerful tsunami that could hit the plant, a court document showed on Tuesday.
Written testimony was submitted to the Chiba District Court on Nov. 24 by Shuji Kawahara, who was head of a team responsible for quake safety issues at the now-defunct Nuclear and Industrial Safety Agency (NISA) — the predecessor of today’s Nuclear Regulation Authority.
Kawahara’s testimony showed that Tepco may have missed an opportunity to examine the possibility of a tsunami disaster almost a decade before such a crisis came to pass in 2011, when massive waves knocked out critical cooling systems at the Fukushima No. 1 plant.
The testimony was submitted as part of a lawsuit filed by Fukushima evacuees seeking compensation from the utility and the central government.
The crippled plant has spewed a massive amount of radioactive material into its surroundings, forcing numerous residents to temporarily evacuate. Many have completely abandoned their hometowns.
Contacted by The Japan Times, Tepco spokesman Norio Okura declined to comment, saying “the matter is related to the ongoing lawsuit.”
In the court documents, Kawahara maintains that NISA asked Tepco to conduct a tsunami simulation in August 2002, highlighting emails that summarize discussions at NISA-Tepco meetings that were sent to related parties later the same month.
NISA made the request because a government expert committee for quake research published on July 31, 2002, a report warning that a major tsunami event could hit anywhere along the Pacific coast of Japan, Kawahara said in the statement.
The report concluded that a major tsunami could hit somewhere along the coastal areas from Tohoku to Chiba Prefecture, with a probability of 20 percent over the next 30 years.
Tepco representatives visited NISA officials on Aug. 5 to discuss the report. But Tepco officials “resisted for 40 minutes” during the meeting and eventually turned down NISA’s request, according to a copy of Kawahara’s written statement, seen by The Japan Times on Tuesday.
In the statement, Kawahara said he believes Tepco rejected the request because “it would take substantial time and expense to carry out a simulation,” and because there was no evidence strongly suggesting such a quake and tsunami could actually hit the Fukushima plant.
Rejecting the proposal, Tepco officials cited a research paper written by two seismologists who played down the possibility of such a quake-tsunami disaster, according to Kawahara.
NISA didn’t override Tepco’s refusal. Kawahara said he believes NISA’s decision at the time was “justifiable.”
In the spring of 2008, Tepco conducted a simulation and concluded that tsunami as high as 15.7 meters could hit the Fukushima plant. But the firm still did not take action before the 2011 disaster, instead saying the simulation was based on a hypothetical scenario and that there was no evidence suggesting such powerful tsunami would actually engulf the Tohoku region.
In its ruling on Sept. 22, Chiba District Court denied any central government responsibility but ordered Tepco — now Tokyo Electric Power Company Holdings Inc. — to pay additional compensation of ¥376 million to 42 evacuees. Both Tepco and the plaintiff have appealed to a higher court.