David Lochbaum, UCSIn his blog entitled "Nuclear Autopsies," David Lochbaum, Director of the Nuclear Safety Project at Union of Concerned Scientists, cites radiation impacts on reactor metal as his first example of the value of performing destructive testing on permanently shutdown nuclear power plant structures and components.
Regarding the baffle plate and core barrel materials "harvested" from the defunct Zorita reactor in Spain, he writes:
Metal specimens attached to the core barrel and other internal components are periodically removed during refueling outages over the reactor’s lifetime for laboratory analysis of radiation effects. The Zorita samples supplement those insights.
Radiation impacts on reactor metal are a grave concern for reactor pressure vessel (RPV) safety. Beyond Nuclear has intervened against any further regulatory weakening at the worst neutron embrittled RPV in the U.S., at Palisades in MI. Neutron bombardment of RPV walls and welds increases the risk of a pressurized thermal shock (PTS) RPV fracture (like a hot glass under cold water -- and 2,200 pounds per square inch of pressure!), which would lead to Loss-of-Coolant-Accident (LOCA), core meltdown, and a high likelihood of catastrophic radioactivity release (see Fairewinds Energy Education's short, humorous educational video about PTS risks, "Nuclear Crack Down?").
Of deep concern is the industry and NRC practice of over-reliance on computer modeling, probabilistic risk assessment, and extrapolation from "sister plant" data, rather than requiring actual hard physical data from Palisades' own RPV itself. NRC is allowing Palisades to go 16 years (from 2003 to 2019) without doing a single capsule pull/test, even though Palisades has four capsules available to extract and analyze.
Lochbaum's "Nuclear Autopsies" blog concludes:
The nuclear industry and the NRC seek to expand those insights by harvesting materials from previously un-examined plant areas. These collections permit real data to replace positions established by extrapolating from other real data and/or by computer analyses. Hopefully, the real data reinforces previous positions. Either way, the real data supports better decision-making in the future.
Nuclear autopsies yield insights that cannot be obtained by other means.
This makes U.S. decisions to not do nuclear autopsies in the past all the more objectionable. For example, the Yankee Rowe RPV was not autopsied, but was instead simply buried in a leaking ditch in Barnwell, SC, even though neutron embrittlement of the RPV forced the reactor's shutdown in the early 1990s. An autopsy on Yankee Rowe could have shed tremendous light on the RPV embrittlement concerns at Palisades. For, as Lochbaum himself recently observed:
"Embrittlement is the issue that compelled the owners of the Yankee Rowe nuclear plant to permanently shut it down in September 1991.
Palisades has the least embrittlement margin of any U.S. nuclear power reactor vessel. And it would not be allowed to operate if the standards applied to Yankee Rowe were applied to Palisades."
This photo shows the initial leg of the shipment of Big Rock Point's radioactive RPV, by heavy haul truck, before being loaded onto a train. The 25 foot by 13 foot cylindrical shell, Type B, transport container used to ship the Big Rock Point RPV from northern MI to Barnwell, SC for burial in Oct. 2003. The shipment was protested with a non-violent civil disobedience action in a Walbridge, OH railyard, resulting in two arrests. The 290-ton load damaged the rails in southeast MI, as well as in the Carolinas, resulting in the later derailments of other trains following on its wake.(Citizens Awareness Network protested the environmental injustice of burying Yankee Rowe's radioactive RPV in a leaking ditch in the predominantly African American community of Barnwell, SC. Citizens Awareness Network hauled a mock nuclear waste container from western Massachusetts, through numerous states, to SC, holding press conferences along the way to educate "transport route" communities of the risks.
Yankee Atomic, owner of Yankee Rowe, followed them. Yankee Rowe's PR head attempted to rebut Citizen Awareness Network with follow on interactions with the news media along the route.
So too was Connecticut Yankee's RPV.)