[ RadSafe ] "g" vs. Richter scale - Edison Power spokesman

[Michael LaFontaine, P. Phys.]

I haven't seen the referenced interview, but having been involved in 
nuclear equipment qualification, I understand the spokesman's 
reference to "g." When qualifying nuclear Class 1E (safety-related) 
equipment, among other criteria, the equipment must demonstrate 
functionality following a design basis event (e.g., 
seismic/earthquake) plus 10% margin - this value is based on the 
maximum "expected" g acceleration for the locale in which the reactor 
is sited. Qualification for North American reactors (and some 
international ones), follows the guidelines of IEEE Standard 323. The 
Richter scale is not referred to.

Our Japanese colleagues apply the same qualification rigor to their 
designs. As Maury indicated, "this was damage caused by truly one of 
the worst of earthquakes and tsunamis ever."


Michael LaFontaine, P. Phys.