Monday, June 6, 2011

#Radiation from Fukushima I Nuke Plant: It Was 850,000 Terabecquerels, NISA Now Says, and Not 370,000

In April when it nonchalantly raised the INES level of Fukushima I Nuclear Plant accident to "Level 7", the Nuclear and Industrial Safety Agency (NISA) said the total amount of radioactive materials (iodine and cesium) released into the atmosphere from the plant was 370,000 terabequerels.

Now it's been revised to 850,000 terabecquerels, 130% jump from 370,000.

Why the revision? NISA says it underestimated the release from the Reactors 2 and 3.

And remember, the contaminated water at Fukushima I Nuke Plant contains 720,000 terabecquerels of radioactive iodine and cesium.

Slowly and steadily approaching Chernobyl.

From Mainichi Shinbun English (6/7/2011):

The Nuclear and Industrial Safety Agency (NISA) on June 6 revised the level of radioactivity of materials emitted from the crisis hit Fukushima No. 1 Nuclear Power Plant from 370,000 terabecquerels to 850,000 terabecquerels.

The Cabinet Office's Nuclear Safety Commission of Japan (NSC) had estimated that the total level of radioactivity stood at around 630,000 terabecquerels, but this figure was criticized as an underestimation. NISA officials plan to present the new figure at a ministerial meeting of the International Atomic Energy Agency (IAEA) after reporting it to the NSC.

The NSC and NISA, which operates under the Ministry of Economy, Trade and Industry, announced a figure for the total amount of radioactivity on April 12, when the severity of the Fukushima nuclear crisis on the International Nuclear Events Scale was raised to level 7, matching that of the Chernobyl nuclear accident. In the Chernobyl accident, the total amount of radioactivity reached 5.2 million terabecquerels.

The NSC calculated the amount of radioactive materials released into the air between the outset of the crisis and April 5, based on the amount of radiation from measurements taken near the plant. NISA based its calculations on the state of the plant's reactors.

The latest figure takes into consideration the release of radioactive materials during explosions at the plant's No. 2 and 3 reactors. The INES scale designates leaks of tens of thousands of terabecquerels as level 7 events, and the seriousness of the disaster on the scale will not change as a result of NISA's revision of the amount.


Ian Goddard said...

Wow, the total release jumping from 370,000 TBq to 850,000 TBq is more than doubles the total.

It's like suppose there was a second cluster of meltdowns somewhere else, even worse than the one we've known, this would be mindbogglingly hard to believe. Well effectively that is the case, just that that other disaster got added to this one.

So many safety assumptions and calculations were based on the prior lower estimate. All that's now history and a de factco second disaster even worse just got added to this one.

Wonder if it'll garner a news headline in the US.

Anonymous said...

Robbie001 sez:

Well CNN is busy reporting the inadequacy of US nuclear disaster planning.

And The New York Times is talking about the unknowns of radiation exposure.

Time's eco-blog does kind of have the story but they are reporting a different number (770,000 terabecquerels) and the claim it is still only 10% of Chernobyl's releases.

"One recurring theme that has emerged after Fukushima is the tendency of nuclear experts to underestimate (publicly at least) the severity of the disaster. Today we received further proof of this when the Japanese government more than doubled the estimate for the amount of radiation released from the plant in the immediate aftermath of the crisis in March."

Anonymous said...

Robbie001 sez:

Wow! TEPCO is falling toward delisting the stock has now lost 90% of it's value since Mar. 11th

Tepco's stock dived 28 percent to 207 yen, falling at one point by its daily limit to a lifetime low of 206 yen, down some 90 percent since Japan's March 11 earthquake triggered the utility's nuclear crisis.

The spread on Tepco's five-year credit default swaps spiked after Saito's comment to a record 1,150 basis points, up 200 basis points from Friday. That means it costs $1.150 million to insure $10 million of Tepco's debt against default. Ratings agency Standard & Poor's last week cut Tepco's debt to 'junk' status.

Anonymous said...

Yup, the TEPCO rats are jumping ship.

850,000 vs. 370,000
Half-perspectives strike again. (in America we would call that "half-assed".)

No one believes they were "underestimating", they were downplaying.

Anonymous said...

Robbie001 sez:

One other thing I didn't think about until today did they use radiation detection equipment that could accurately measure above the "magic" 1000mSv they kept reporting in the early days?

"The NSC calculated the amount of radioactive materials released into the air between the outset of the crisis and April 5, based on the amount of radiation from measurements taken near the plant".

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