STOCKHOLM, Oct. 25 — Nature.com’s Geoff Brumfiel reports that the “Fukushima Daiichi nuclear plant in March released far more radiation than the Japanese government has claimed,” according to a new study appearing in the journal Atmospheric Chemistry and Physics.
“The new model shows that Fukushima released 3.5 × 1016 Bq caesium-137, roughly twice the official government figure [1.5 × 1016 becquerels], and half the release from Chernobyl,” writes Brumfiel.
Lars-Erik De Geer, an atmospheric modeller with the Swedish Defense Research Agency in Stockholm, says the higher number is “obviously worrying”.
Andreas Stohl, an atmospheric scientist with the Norwegian Institute for Air Research in Kjeller, who led the research believes that the discrepancy is because Japan estimates never recorded the large quantities of radioactivity that blew east towards North America and Europe.
“Taking account of the radiation that has drifted out to the Pacific is essential for getting a real picture of the size and character of the accident,” says Tomoya Yamauchi, a radiation physicist at Kobe University.
If Stohl and Yamauchi are correct, then the Japanese government’s release estimates only include the radiation that blew over Japan. And according to Stohl’s study, only ONE-FIFTH of radiation release went over Japan:
“About 20% of the caesium was deposited on Japanese territory, while about 80% was deposited in the water.”
Using Stohl’s facts and figures, it appears that the government cesium estimates should be increased FOUR-FOLD.
And recall what a JAEA scientist who helped to develop the Japanese official estimate said, “I think the release from [the spent fuel pool in] unit 4 is not important.” (SOURCE)
Yet the Stohl study also reveals that Spent Fuel Pool No. 4 played a “significant part” in the release of cesium-137. Perhaps four-fold is not enough.
Published: October 25th, 2011 at 1:21 pm ET