2017-10-19 Dry Cask Risks Not Known When Design Approved by NRC -- Diablo Canyon Ind. Safety Committee
Ecological Options Network (2017-10-19) Diablo Canyon Independent Safety Committee
This Page: https://copswiki.org/Common/M1848 Media Link: https://www.youtube.com/watch%3fv%3dktNTtpiJpoU More Info: Helms Proposal
Former Nuclear Regulatory Commission (NRC) Administrative Judge Dr. Peter Lam discloses that the vulnerabilities of Diablo’s Holtec dry cask nuclear waste storage system to stress corrosion cracking - recently documented by Donna Gilmore - was not known to decision-makers 20 years ago, when the NRC approved the design.
Dr. Lam’s disclosure seems to throw into serious question the validity of the design basis of all planned and existing nuclear waste storage systems in California and elsewhere.
This is number four of four excerpts, posted as a public service by EON, from the Slo-Span.org video coverage of the Oct. 19, 2017 meeting of the Diablo Canyon Independent Safety Committee.
DR. PETER LAM (Acting DCISC Chair, Administrative Judge Emeritus -- NRC)
Thanks to Ms. Gilmore, Ms. Donna Gilmore's effort, the awareness of this important issue has increased substantially in the past several years. Ms. Gilmore's research was one of the earliest effort identifying focusing on this important phenomena of stress induced corrosion cracking. As you can hear, from Mr. Strickland and Ms. Gilmore, there is a continuing effort from both sides of the fence to drive forces solution and remedy of this phenomena. Right now it remains in flux.
PER F. PETERSON (DCISC Committee Member, Dept. of Nuclear Engineering, Berkeley)
There is a large difference in the design of the storage and transportation canisters in Europe, Japan, and the United States because the canister designs that are used in Europe and Japan are for systems that reprocess the spent fuel, where the storage time for the spent fuel is short. And so those canisters are designed to be readily opened and closed so that you can easily get the spent fuel back out again. And I've observed in visits to the La Haav facility hot cells where the fuel assemblies removed so they can be reprocessed. In the United States, we have a policy to perform direct disposal of that spent fuel. And so, in designing the storage systems for the dry storage of spent fuel, the focus was on compatibility with the direct disposal of spent fuel rather than reprocessing it. The major desire in going to a welded-shut sealed design was that would have minimized the amount of fuel handling that would need to occur before placing in direct geologic disposal.
And then, if you go to the -- and this is not to say whether Yucca Mountain is a good idea -- the facility design for Yucca Mountain has the capabilities to open canisters and repackage that fuel, but the anticipation is that most or all would go directly into disposal. That explains a lot of the difference because the multipurpose canisters are supposed to serve for interim storage, transportation, and ultimate disposal.
Changing canister designs in a period of time which is realistic that is licensing the European design, it is something we could explore but in the end I don't believe it will be practical because the multiple functions we need for the direct-disposal approach would mean you would not be able to directly use the European Design for this purpose. But we'd have to look into that.
I think that looking a the time scales required to execute Part 72 licensing for different disposal system, find appropriate seismically qualified location on the site to build the infrastructure, that realistically, this could be a very long drawn out process. The simpler solution could be to move to interim storage, if it should be licensed. There have been a number of public meetings in Carlsbad [NM]. It is a very interesting community, very different from California. We're different from other parts of the country. The benefit of having a consolidated site is you would have local capabilities for opening and inspecting and repackaging if necessary, spent fuel that could be associated with it.
Realistically, we already have so many shutdown sites that have already shut down their spent fuel pools. So, that's what it is.
These canisters are holding 32 to 37 fuel assemblies, the permanent repository is designed for smaller ones, and using different materails, such as Alloy-22, so these were never designed to go "right in" to a respository.
No, No, actually the Alloy 22 canisters are designed to -- to -- for the Yucca Mountain design, they will place these canisters -- the whole idea was to avoid having to reopen these things. And so the Yucca Mountain design is compatible with...
Their talking about STAD canisters will hold 8 assemblies. The original... They bought these -- I have a DOE report -- they bought these because they were less expensive at the time was the reason these were bought and I have written documentation of that fact.
And with regards to the impracticality of switching, the NRC, Mark Lombard told me it would be about an 18 month licensing process because they have beefed up their waste side. These [European design] containers meet very high standards and have been used for 40 years in storage. They are no longer reprocessing in Germany so these are... we have no idea how well these thin canisters are doing because we have can't inspect them inside or out. This is not a matter of is it practical or feasible to do it. We have no choice.
Before we move on I would like to offer a disclosure. 20 years ago, I served as a federal administrative judge, sitting on a licensing board to approve the dry cask storage system here at Diablo Canyon. At that time, the Chloride Induced Stress Corrosion Cracking was not known to the licensee,was not known to the licensing board, not known to Holtec. So this is and entirely new development. I'd like to make that disclosure because Gen. Strickland served as a licensing manager during the adjudicatory hearings here in San Luis Obispo.