Society News Archive

30 December 2015
Fukushima Releases: The Truth

Recently, a number of websites have reported grossly false information regarding radioactive releases during the Fukushima Daiichi nuclear accident. Here are the key facts that refute those claims.

The erroneous information cites a recently “declassified report”:

The claim is that the U.S. Nuclear Regulatory Commission (NRC) “declassified” documents about Fukushima in December 2015. The truth is that the documents were requested through the Freedom of Information Act and were provided in May 2012, and more documents were provided in March 2014. None of these documents were ever “classified” in the legal sense.

The erroneous information claims that the report says “25% of the total fuel in unit 2 . . . , 50% of the total spent fuel from unit 3 . . . , and 100% of the total spent fuel . . . from unit 4” was released to the atmosphere:

Yes, these are the hypothetical releases that were evaluated in an attempt to understand the worst possible situation. No, these are not the amounts that were released from the reactors or spent fuel rods.

 The truth is that there was a high degree of uncertainty regarding actual releases early in the accident and continuing for several weeks. As a result, the NRC asked the National Atmospheric Release Advisory Center (NARAC) to provide dose estimates for two or more hypothetical scenarios to set bounds on the potential protective actions that might be taken.

 The NRC documents clearly identify those percentages as a hypothetical bounding case, which they asked NARAC to consider. The hypothetical releases were described as a “worst-case scenario” and “realistic worst case.” The NARAC report clearly states the scenario was hypothetical, and the documents also state “There is no evidence this scenario has occurred.”

Read the truth for yourself. These are the notes provided by the NRC on 8 May 2012 and 7 March 2014.

What was released?

Actual (not hypothetical) data show that ultimately there was major fuel damage in Units 1, 2, and 3 reactor cores. Through about mid-March of 2011, releases from these cores were primarily volatile fission products released to air, as well as some soluble fission products released to water. There has been no evidence of releases from any of the on-site spent fuel pools ( The total release from the Fukushima accident was about 10-15% that of Chernobyl, though by element, the iodine release was less than 25% and the cesium release was less than 45% of the Chernobyl releases (

Want more true facts about the Fukushima accident?

Check out the reputable resources listed on the Health Physics Society’s website at

Barbara Hamrick, CHP, JD