I thought there was already a topic on this (could have sworn that I read most of the 18 pages) but I can't seem to find it.
Anyways, I saw something on Good Morning America this morning about how the plants are going to be shut down until August (at best), so I decided to look more into the issue. Most of what I had to go on were news articles, which when it comes to nuclear I trust the news less than my students at NPTU when they say they were at work for 12 hours and there wasn't a single person available for a check out. I was wondering if anyone could see if what I've put together is fairly accurate.
San Onofre decides to do a S/G replacement and during this replacement they do what has become fairly standard and use Inconel 690 vice the old 600 to combat issues with Stress Corrossion Cracking. Inconel 690 does have a known draw back that is it is susceptible to fretting wear but many plants have combated this issue with Inconel 690 through various means and San Onofre should have taken this into account when designing the new S/G's (I'm not sure if the engineers did or not plan for it, that was something that was fairly unclear when looking around on the net). Then Mitsubishi added about 380 tubes to each generator (I'm assuming to upgrade the output of the plant at a future date?). What I was able to find was a statement in a news article that Mitsubishi didn't plan for the extra vibration from the other 380 tubes which probably caused the extremely rapid fretting wear.
Can anyone fill in blanks for me and tell me how accurate I am? I wrote one of my final papers on the transition from Inconel 600 to Inconel 690 and I'm actually pretty proud of that paper, so that's why this issue has sparked my intrest,
.
Thanks,
Josh
