Luis Reyes, Regional Administrator for the Nuclear Regulatory Commission, Commenting on AP1000 Shield Design Concerns

During the Nuclear Construction Summit being held at the Dupont Hotel in Washington, DC on October 26 and 27, I had the opportunity to listen to a talk by Luis Reyes, the Regional Administrator for NRC region II in Atlanta, GA. Under the current organization, Mr. Reyes has overall responsibility for all nuclear construction activity oversight. He gave a good talk about the way that the organization is getting ready for new plant construction and how it is gaining experience by inspecting during the construction processes for new enrichment facilities and the MOX fuel production plant being built at the Savannah River Site to recycle former US weapons material.

There was an opportunity after his talk for questions from the audience. Since so many commenters on this blog and in other media have made a lot of guesses about the potential impacts of the recent announcement by the NRC that they are not yet satisfied with the AP1000 shield building design, I thought it would be a good chance to get a bit more detail about the concerns and what the agency thinks of the difficulty of solving the issue. (Dan Yurman published one of the more thoughtful and informed pieces as an exclusive for The Energy Collective titled Westinghouse Gets a Scare from the NRC)

Here is the question I posed along with Luis Reyes’s answer:

Rod Adams: Mr. Reyes, can you help us understand a little bit more about the concerns on the AP1000 shielding design?

Luis Reyes: Yes. I think there is a lot of misinterpretation of that issue. The AP1000 design was certified by the NRC and we have reviewed that issue. In one of the subsequent revisions they made some changes to the building to try to facilitate modular construction. When they (Westinghouse) did that, they introduced some new techniques in terms of anchoring the walls, the side walls. And the staff raised some questions with the stability of that particular issue, to the point where we decided that was not acceptable to us. They are very easy engineering fixes regarding anchoring and supports et cetera, et cetera.

So it is not an insurmountable issue. So what is happening now is that Westinghouse is taking a look at how they can resolve the issue yet still have a lot of flexibility for the module construction.

There is a forthcoming meeting with the NRC where they are going to present the approach and we’ll pursue it. I do not see this as a significant, insurmountable engineering issue. The question of the change is to be able to do the modular construction and keep the construction schedule in the 4-6 year time frame with existing, engineering acceptable techniques. I think you are going to see a resolution pretty soon.

Based on public statements from Westinghouse as quoted by Dan Yurman in the article linked above, it sounded like the company wanted to fix the blame for the issue on a change made to respond to the NRC’s new aircraft impact rules. It appears that there is also some blame to place on the company for making a change to their certified design to accommodate construction techniques that were not envisioned during the original effort that went through the certification process. Sometimes, design engineers cannot resist the temptation to tweak their work in an attempt to improve it; in a business where cost is often driven by predictability it can be useful to resist changes, especially those that have not been fully tested in full scale mock-ups.