From: Fleger, Stephen
Sent: Tuesday, April 05, 2011 6:09 PM
To: Barnes, Valerie; Peters, Sean; Desaulniers, David; Boggi, Michael; Martin, Kamishan; Marble, Julie; Xing, Jing;
D’Agostino, Amy; Morrow, Stephanie; Lapinsky, George
Subject: RE: CONSIDERATIONS OF WGHOF WITH RESPECT TO FUKUSHIMA EVENT
Hey Val –
I just returned from briefing the ACRS on our updated Advanced Rx R&D Plan (NGNP/HTRG plan) and I need to get across town for a 6:30 pm function so I can’t spend much time on this but the one thing that strikes me about the Fukushima event from a HOF perspective is the consistency with which the PRA/HRA “worst case” scenario builders underestimate the probability of common cause failures.
Every major nuclear accident has been worse than the hypothesized worst-case. TMI, Chernobyl and now Fukushima. For TMI the “implausibility’s” surrounded the hydrogen buildup in the RPV and core melt. For Chernobyl it was the positive reactivity void coefficient leading to multiple explosions. For Fukushima it was damage to the T/G, failure of backup power systems following a station blackout, and containment explosions resulting from hydrogen buildup as a result of an earthquake followed by a tsunami that happened in a country that arguably has one of
the best earthquake prediction & mitigation systems in the world.
Maybe this might be worth looking into?