There was some somewhat bad news in the nuclear world this week. Duke Energy announced that the Crystal River Unit 3 (CR3) nuclear plant, that was obtained as part of the Duke-Progress merger, will be decommissioned rather than repaired after not operating since a 2009 outage.
During the 2009 outage, a hole had to cut in the containment to allow for new steam generators to be installed. As part of cutting the hole, the containment's concrete was cracked. An initial crack was repaired, but then in 2011, there was additional damage. This put Progress Energy, and following the merger Duke Energy, into the position of having a very tough decision to make of whether it would prove to be economical to repair the containment. It should be noted that the damage was not irreparable damage, but that the repairs carried enough uncertainty (both cost and schedule-wise) that the damage proved to be uneconomical to repair.
The 2009 outage included replacing CR3's steam generators. Replacing steam generators is far from a trivial maintenance operation, considering steam generators weigh in the hundreds of tons. Here is a rather incredible time-lapse video of the replacement of the 4 steam generators at Sequoyah Unit 2 which occurred towards the end of 2012.
Since Crystal River 3 never came back online following that outage, the steam generators have never entered service and should be brand new for all intents and purposes. With such valuable pieces of equipment being free of any wear and tear (other than being welded into place within the CR3 reactor coolant system, feedwater system, auxiliary feedwater system, steam generator blowdown, and main steam systems), it would be nice if they could somehow be re-used somewhere for their designed purpose of generating steam (with zero emissions, of course).
Being the entrepreneurial thinker that I am, I spent a few minutes trying to think of a few options to re-use these very valuable components. Here are the 3 options, in the order in which they came to mind.
1. San Onofre Nuclear Generating Station (aka SONGS) Units 2 and/or 3This would almost be a perfect match, considering the SONGS early-life steam generator wear issue that has kept both Units 2 and 3 there shut down since January 2012. Sadly though, there are several extremely intractable problems that would arise from trying to fit the CR3 steam generators into either unit at SONGS that would make such an arrangement an impossibility economically. CR3, being a B&W-designed plant, has a completely different steam generator design than the Combustion Engineering-designed plants at San Onofre. The engineering and modifications that would be necessary to put once-through B&W steam generators (OTSGs) into a Combustion Engineering plant with U-tube steam generators would be intractable, sadly. It would be pretty far beyond trying to fit a square peg into a round hole. The biggest reason for this being that OTSGs have the primary side water enter at the top of the steam generator, whereas U-tube steam generators have the primary side enter at the bottom.
Additionally, Crystal River’s lower designed core thermal power (2609 MWt) would be poorly matched to the designed core thermal power of either of the San Onofre units (3438 MWt). The power level would be rather close to the 70% level that has been proposed by the owners of San Onofre Unit 2 for the trial 5-month period after restart.