25 Mars 2013
March 25, 2013
The industry ministry failed to improve nuclear protection at an off-site center (OFC) of the crippled Fukushima No. 1 nuclear power plant at the request of the internal affairs ministry because it assumed a similar crisis at the plant was not possible, according to government sources.
The Internal Affairs and Communications Ministry pointed out two years before the outbreak of the nuclear crisis at the plant in March 2011 that the OFC, which is supposed to serve as a control center during a nuclear disaster, had such flaws as insufficient protection against radioactive substances.
The Economy, Trade and Industry Ministry instead prepared a list of anticipated questions and planned answers to emphasize the safety of the OFC, according to documents released by the ministry after an information-disclosure request by The Yomiuri Shimbun.
An OFC is meant to serve as a countermeasure headquarters in the event of a nuclear crisis. OFCs have telecommunications equipment and computer terminals with systems for simulating nuclear accidents.
The OFC of the Tokyo Electric Power Co. plant became inoperative after the crisis due to high radiation levels.
As the ministry's inaction relied on the "myth of nuclear plant safety," questions are emerging as to the laxness of safety standards and responses at the time.
Myth of safety
In February 2009, the internal affairs ministry asked the industry ministry to improve nuclear safety measures at five nuclear plant OFCs within 10 kilometers of the Fukushima plant, Tohoku Electric Power Co.'s Onagawa plant, Chubu Electric Power Co.'s Hamaoka plant, Hokuriku Electric Power Co.'s Shika plant, and Shikoku Electric Power Co.'s Ikata plant.
The ministry pointed out that as the OFCs did not have ventilation systems with air-cleaning filters, there was a risk that radioactive substances could flow into the facilities during a nuclear disaster.
According to one document from March 2009, the industry ministry's defunct Nuclear and Industrial Safety Agency (NISA) discussed how to respond to the internal affairs ministry's recommendation.
At the time, NISA officials used as a reference the government's nuclear disaster prevention guideline, which mentioned the 1986 disaster at Chernobyl nuclear power plant in the former Soviet Union. The disaster, in which a massive amount of radiation was scattered, was designated a Level 7 nuclear crisis, the most severe rating for nuclear accidents at the time.
As the guideline stipulated that Chernobyl "was an accident that occurred at a nuclear plant with different design concepts from Japan's," the then economy ministry concluded "Japan does not need to assume" the possibility of a nuclear accident on a similar scale.
Six months after the internal affairs ministry's request, the economy ministry replied that "ventilation [of the OFCs] would be halted to keep the inside airtight," on the assumption that radioactive discharge would occur for a short time even if a nuclear incident occurred.
The economy ministry's explanation of the safety of the OFCs was aimed at alleviating concerns from officials of local governments hosting nuclear power plants. The planned answers included such phrases as "filters aren't needed," and "the OFCs have no flaws."
'It was a big mistake'
In the aftermath of the Fukushima nuclear disaster, radiation levels rose in the Fukushima No. 1 plant's OFC about five kilometers away, as the facility's backup generator had been damaged by the preceding earthquake on March 11, 2011.
NISA and other officials who were stationed in the OFC evacuated to the city of Fukushima, about 60 kilometers from the plant, four days after the outbreak of the crisis.
Incorporating lessons learned from the disaster, in September 2012, the government set a new guideline making the installation of radiation filters and other safety equipment mandatory for OFCs--improvements that were already pointed out by the internal affairs ministry.
"The safety guideline at the time stipulated that 'It is very unlikely that an accident similar to the Chernobyl disaster will occur,'"a former NISA official told The Yomiuri Shimbun. "We followed the view. However, it was a big mistake."
The OFCs were set up in the wake of a 1999 criticality accident caused by JCO Co. in Tokai, Ibaraki Prefecture.
Sixteen OFCs were set up in 16 commercial nuclear power plants and six in other nuclear facilities, such as a reprocessing plant for spent nuclear fuel.