How Old Is Too Old for a Nuclear Reactor?
http://www.technologyreview.com/news/544211/how-old-is-too-old-for-a-nuclear-reactor/
Charpy V Notch testing of reactor vessel coupons reveals the severity of neutron embrittlement.
That pretty much tells you what "too old" is.
Embrittlement is a function of alloy and neutron fluence. Uprate the power, raises the neutron flux, increased embrittlement, ultimately a shorter reactor vessel life.
Something we haven't seen is - RPV replacement. Styeam Generators, Coolant Pumps, and piping - but the asset is near infinitely extendable by replacing aging RPVs.
Quote from: rlbinc on Dec 09, 2015, 12:53
..................Something we haven't seen is - RPV replacement............
"we" meaning commercial power nukes AIUI,...