Fukushima Watch: Authority Chairman Not Convinced Level 3 Needed

Just a week after Japan’s nuclear regulator declared the leak of radioactive water at the Fukushima Daiichi nuclear plant big enough for a Level 3 incident rating, the regulator’s head is wondering publicly if it really deserved that rating after all.

Based on the International Nuclear and Radiological Event Scale, a Level 3 rating is considered a “serious incident.” For the sake of comparison, the 2005 leak of 83,000 liters of radioactive waste at the Sellafield nuclear reprocessing site in the U.K. was also given a Level 3 rating on the International Atomic Energy Agency’s scale. Both the Fukushima Daiichi and the Chernobyl disasters were assigned the scale’s highest Level 7 rating.

While it might seem like Tokyo Electric +1.60%, the plant’s operator, would h******e a precise measurement of the amount of water that had been leaked, the current incident actually started with puddles discovered outside a storage tank of contaminated water. When workers subsequently checked the levels of the 1,000 metric ton water tank, they found only 700 tons. The missing water was presumed to h******e drained into a surrounding trench.

“We don’t think the leak was exactly 300 tons,” said Shunichi Tanaka, chairman of the Nuclear Regulation Authority, said at a regular press conference on Wednesday. “It could be much more or much less,” he added, saying that Tepco calculated the amount based on the assumption that the tank had been full.

“300 tons is a huge amount. If workers patrolled twice a day without noticing it leaking, I don’t understand,” Mr. Tanaka told reporters. “It wouldn’t be desirable, but we would h******e to change the rating if the leak turns out to be much smaller.”

Tepco has been forced to deal with ever-rising contaminated water levels at the Fukushima plant since the March 11, 2011 disaster. Given the sheer scope of containing the disaster, the way the utility has managed the plant has been very disorganized.

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in the latest leak, a panel investigation has revealed that only nine people supervised roughly 1,000 tanks at the site with two of them on a rotation shift. They patrolled the tanks twice a day to check if there are any signs of leaks, but they didn’t make records.

On Tuesday, Tepco said it would increase the number of patrollers to about 60 people.

“I h******e not been convinced with the data from Tepco. We need to collect more to make our own judgment,” said Mr. Tanaka.

The supposedly huge water leak is reminiscent of a case this past April, when Tepco announced up to 167 tons of contaminated water leaked from underground storage pools. At that time, Tepco hurriedly calculated the number and announced it to the public. But several weeks later, it revised down the amount sharply to about a few dozens liters after careful double checks.

A Tepco spokeswoman said “it’s true that we calculated 300 tons. We cannot say whether we will or we won’t change it later.”

在日本核能監管人員公佈福島核設施放射性廢水泄漏以足以達到3級一週後，監管負責人則公開質疑這是否真的達到這一評級。

基於國際核及放射性事件等級表，3級則被認為是“嚴重事故”。與之相較，2005年英國Sellafield核處理設施83000升放射性廢物泄漏也被國際原子能機構評定為3級。福島與切爾諾貝利災難都被評定為最高的7級。

儘管似乎該設施經營者，東電公司，可能對泄漏水的數量有精確測量，但目前的事件實際上最早於污染水處理箱外的水坑中發現的。當工人隨後檢查1000噸水箱時，他們發現僅剩700噸。缺少的水推定是流入了附近的溝渠中。

“我認為泄漏量不是正好300噸，”核監管局主席Shunichi Tanaka週三在常規媒體會議上説道。“這可能多很多或是少很多，”他又説道，並稱Tepco測算的數據是基於水箱是裝滿的.這一假設。

“300噸是個大數目。如果工人們每天巡查兩次卻未能注意到漏水，我無法理解，”Tanaka先生對記者説道，“這不是人們所想要的，但如果泄漏數量的確小很多，我們將不得不改變評級。”

自2011年3月11日地震後，Tepco被迫處理福島核電站不斷增高的污染水量。縱觀除災過程，該設施管理方式十分紊亂。在最近的泄漏中，小組調查披露只有9人監管近1000個水箱，採用2人輪班制。他們每天兩次巡查水箱以檢查十分有漏水跡象，但他們並未做記錄。

週二，Tepco表示其將把巡查人員人數增加到約60人。“我不相信Tepco的數據。我們需要收集更多資料做出我們自己的判斷，”Tanaka先生説道。

這一推測的大量水泄漏讓人想起了4月份的一次事件。當時Tepco宣佈有167噸受污染水從地下儲水池中泄漏。當時，Tepco匆忙計算數據並將之公之於眾。但在幾周後，其在進行仔細的二次核查後將數據減為僅有幾十升。

Tepco的一名發言人表示“我們的確測算為300噸。但我們沒法説之後我們會不會改變數據。”