The Nuclear and Industrial Safety Agency and the Nuclear Safety Commission on Tuesday provisionally raised the severity level of the crisis at Tokyo Electric Power Co.’s stricken Fukushima No. 1 nuclear power plant from level 5 to the maximum 7 on the International Nuclear Event Scale — the same level designated for the world`s worst nuclear accident at Chernobyl in 1986.
NISA estimated that the amount of radioactive materials in terms of radioactive iodine-131 released into the air from the Nos. 1, 2 and 3 reactors at 370,000 terabecquerels (one terabecquerel being 1 trillion becquerels) and the NSC at 630,000 terabecquerels — far exceeding the criterion of tens of thousands of terabecquerels for level 7.
On March 18, NISA had provisionally set the level at 5, the same level as the Three Mile Island accident in 1979. Even after it became clear that the severity of Fukushima No.1’s crisis exceeded that of the TMI accident, the government took such a long time before raising the level.
The government should realize that the delay has highly damaged Japan’s trustworthiness. The possibility cannot be ruled out that the adoption of the low level of severity has adversely affected the government and Tepco’s decisions in their efforts to mitigate the nuclear crisis.
NISA says the amount of radioactive materials released from Fukushima No. 1 is about 10 percent of that from the Chernobyl plant. But the explanation creates a false sense of security. The amount does not cover radioactive materials released into the sea. The total amount of radioactive materials existing in the Nos. 1, 2, 3 and 4 reactors at Fukushima No. 1 is much greater than that at Chernobyl or TMI. At Fukushima No. 1, a crisis involving four reactors — compared to the one reactor at Chernobyl and TMI — has been going for more than a month. The government and Tepco must find a way to sufficiently cool the reactors and spent fuel storages without releasing contaminated water out of the reactors.
The government should also announce detailed updates frequently on radiation levels at various places to enable people to better protect their health and lives.