NRC Spokesperson: We Don't Rank Plants by Seismic Risk

[Updated: See below for Bill Dedman's response to the NRC letter.]

The assertions made in an msnbc.com article published March 16, which Patch to soon after, have been challenged by a Nuclear Regulatory Commission spokesman.

In the article, investigative reporter Bill Dedman wrote that, "the U.S. Nuclear Regulatory Commission has calculated the odds of an earthquake causing catastrophic failure to a nuclear plant here."

Below is the letter the NRC issued in reply:

Regarding: ""

The MSNBC [msnbc.com] story has to do with a seismic risk ranking it created. It is not the result of an NRC review. The NRC does not rank plants by seismic risk.

The objective of the NRC study was to perform a conservative, screening-level assessment of earthquake risk. The NRC results to date should not be interpreted as definitive estimates of seismic risk. The nature of the information used to make these estimates are useful only as a screening tool.

Currently operating nuclear power plants in the U.S. remain safe, with no need for immediate action. This determination is based on NRC staff reviews of updated seismic hazard information and the conclusions of the screening panel. Existing plans were designed with considerable margin to be able to withstand the ground motions from the largest earthquake expected in the area around the plant.

Neil Sheehan, NRC Public Affairs

UPDATE: Bill Dedman of msnbc.com responded to the NRC statement in a at West Chester Patch:

Our story made clear that the NRC does not rank the nuclear plants. But it does publish its estimates for each plant, by which we ranked the plants.

If the newspaper starts publishing the American League East standings in alphabetical order, it's entirely appropriate for the reader to put the teams in order by winning percentage.

Don't be misled. NRC hasn't said our numbers are wrong. I checked my interpretation with Scott Burnell in Public Affairs, who checked with the NRC technical staff before publication. No challenge from NRC has arrived after publication.

After all, they're NRC's numbers.

What NRC is saying is that it doesn't do rankings. That's right. We did, from NRC's data. Just as the story says.

You can see for yourself in the NRC report that:
-- NRC says the risk of quakes in the central and eastern states is higher than previously thought.
-- It still thinks plants are safe.
-- but their margin of safety is reduced.
-- and some plants are now near the point where they should be re-examined, and perhaps retrofitted.
-- and the staff says this should now move from being a research issue to a regulatory issue.
-- and it has made its best estimates of the frequency (chance, odds) of an earthquake that would cause core damage to a plant.

A link to the report is on our report: http://www.msnbc.msn.com/id/42103936/ns/world_news-asiapacific/

Bill Dedman, msnbc.com