Water, Earth, Sky

Scott Shenk writes about the environment.

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More on nuke plants’ earthquake risk

As the nuclear disaster in Japan continues, the Nuclear Regulatory Commission put out  a Q&A addressing seismic issues at  U.S. nuclear power plants. The agency says it   does not rank individual plants’ risk of damage in an earthquake after an MSNBC story last week  used NRC data to compile such a rating.  It called the rankings “highly misleading.” The MSNBC story listed the North Anna Units 1 and 2 as 7th out of the top 10 plants most likely to have reactor core damage in an earthquake.  The topic is of interest here because  North Anna Power Station is built in one of Virginia’s active earthquake zones. See my most recent stories about North Anna here and here.


  • Bill Dedman


    Don’t be misled by NRC’s non-denial denial.

    NRC hasn’t said our numbers are wrong. I checked my interpretation with NRC Public Affairs. 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. If the NRC was publishing the American League East standings, it would list them alphabetically. (That’s OK with me; the Yankees would be last.)

    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 technical 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, and those are in Appendix D, last column on the right. The links are at the bottom of the article.