RA-08-114, NRC Response to D. Lochbaum Regarding Current Condition of Oyster Creek Drywell and Associated 2.0 Factor of Safety Margin

NRC Response to D. Lochbaum Regarding Current Condition of Oyster Creek Drywell and Associated 2.0 Factor of Safety Margin

ML081840630
Person / Time
Site:	Oyster Creek
Issue date:	07/01/2008
From:	Dapas M L Region 1 Administrator
To:	Lochbaum D Union of Concerned Scientists
Barkley R S
Shared Package
ML081780002	List: ML081840630 RA-08-114, NRC Response to D. Lochbaum Regarding Current Condition of Oyster Creek Drywell and Associated 2.0 Factor of Safety Margin
References
IR-06-007, RA-08-114
Download: ML081840630 (4)

Text

July 1, 2008

David Lochbaum Director, Nuclear Safety Project Union of Concerned Scientists 1825 K Street NW Suite 800 Washington, DC 20006-1232

Dear Mr. Lochbaum:

I am writing in response to your letter to Sam Collins dated June 20, 2008, in which you indicated that there were two points raised in a June 6, 2008 letter to Mr. Collins from Janet Tauro of the Grandmothers, Mothers, and More for Energy Safety, that "caught your attention." Ms. Tauro's letter pertained to remarks made at the 2008 Oyster Creek annual assessment meeting. I am responding to your letter on behalf of Mr. Collins, since I was the senior NRC manager in attendance at that meeting.

Regarding your question with respect to the staff's remarks at the meeting on the current condition of the Oyster Creek drywell and the associated 2.0 factor of safety margin, I stated at the annual assessment meeting that the Region I staff had reviewed the ruling from the Atomic Safety and Licensing Board (ASLB) proceeding on this subject and did not identify any new information that called into question previous conclusions regarding the current safety condition of the Oyster Creek drywell. In its ruling, the ASLB concluded that the drywell shell will maintain the necessary safety margin during the period of extended operation based on the frequency of AmerGen's planned ultrasonic testing measurements, in combination with other elements of AmerGen's aging management program. The basis for the ASLB's conclusion is documented in its published ruling.

The basis for the NRC staff's position regarding the condition of the drywell shell is documented in the staff's submissions to the ASLB and transcribed testimony provided by the staff during the September 24-25, 2007, ASLB evidentiary hearing. Region I staff, in concert with staff from the NRC headquarters office, were responsible for reviewing the adequacy of the protective coating, monitoring and maintenance program for the Oyster Creek drywell to ensure that aging effects on the drywell going forward are managed. The results of this review are documented in NRC Inspection Report 50-219/2006-007, which is part of the evidentiary record in the Oyster Creek license renewal proceeding as Staff Exhibit 5, and is enclosed. Region I also issued NRC Inspection Report 50-219/2006-013, a copy of which is also enclosed, which documented the results of the extensive evaluation by the NRC inspection staff of the operability of the drywell. That report specifically states that the NRC staff determined, "there were no safety significant conditions with respect to the primary containment that would prohibit plant startup and there was reasonable assurance that the primary containment is capable of performing its design function throughout the upcoming operating cycle [fall 2006 through the fall of 2008]."

During the recent Oyster Creek annual assessment meeting, I did not state that the drywell factor of safety margin was specifically 2.0, but rather I referred to the ASLB's published decision in this matter, and stated that we (the NRC) had reasonable assurance that the safety factor was at least 2.0. In their decision, the ASLB stated that, "although the precise value of D. Lochbaum 2 the safety factor can not be determined without performing more extensive measurements and actual calculations, compliance with the acceptance criteria - which incorporate several significant conservatisms - permits the conclusion that the safety factor is at least 2.0, especially given that the thickness of the shell is on average greater than 0.736 inches." In addition, ASLB Judge Baratta wrote that, "when all things are taken into account, including the actual thickness, the safety factor is likely to be greater than two, which I concur with."

As you know, an appeal of this recent ASLB decision is now before the Commission. Based on this ongoing legal action, it would be inappropriate for me to discuss this decision further. However, I have provided as an enclosure, the letter Sam Collins recently sent to Ms. Tauro, along with the attachments to that letter and copies of the two recent submittals by the NRC staff in this proceeding, dated June 11 and 18, 2008.

Regarding your comment/question with respect to the statement made by Richard Conte at the meeting, as characterized by Ms. Tauro, I promptly clarified the NRC's position on the current safety condition of the Oyster Creek drywell, reiterating that the drywell is considered operable, based on a thorough NRC evaluation and inspection. In that clarification, I again made reference to the documented basis for that operability determination (NRC Inspection Report 50-219/2006-013). I also commented that if the NRC obtains any new information that indicates the operability of the drywell is in question, the NRC staff will take appropriate regulatory action to ensure public health and safety. However, as I noted earlier, the NRC has not identified any new information that indicates that the Oyster Creek drywell does not have the necessary margin of structural strength to prevent the drywell shell from buckling under a worst case condition, which in this case is during refueling, when the refueling cavity connected to the top of the drywell is fully flooded.

If you have any further questions regarding my response to your letter or the NRC staff discussion at the Oyster Creek annual assessment meeting, I can have my staff arrange a conference call. Please contact Richard S. Barkley, of my staff at (610) 337-5065 if you have any further questions in this matter.

Sincerely,

/RA/ Marc L. Dapas Deputy Regional Administrator

Enclosures:

1) Letter to Ms. Janet Tauro, GRAMMES, dated June 23, 2008 2) NRC Inspection Report 50-219/2006-007, dated September 21, 2006 3) NRC Inspection Report 50-219/2006-013, dated January 17, 2007 4) NRC staff briefs responding to the Commission's Order on Oyster Creek, dated June 11 and 18, 2008

D. Lochbaum 3 cc w/encls via email: NJ Senator Christopher J. Connors (senconnors@njleg.org) Paul Gunter (paul@beyondnuclear.org) Peggi Sturmfels (psturmfels@cleanwater.org) Jeff Brown (jbnj@comcast.net) Janet Tauro (jtauro@comcast.net)

Paula Gotsch (paulagotsch@comcast.net) Willie deCamp (Wmdecamp@cs.com) Jill Lipoti (Jill.Lipoti@dep.state.nj.us) Lisa Jackson (Lisa.Jackson@dep.state.nj.us) Julie LeManse (jlemense@easternenvironmental.org)

Richard Webster (rwebster@easternenvironmental.org) Adam Zellner (adam.zellner@gov.state.nj.us) Arvin Ganesan (Arvin_Ganesan@lautenberg.senate.gov) Lisa Plevin (Lisa_Plevin@lautenberg.senate.gov) Joan Zielinski (joan.zielinski@mail.house.gov) Ryan Goodwin (ryan.goodwin@mail.house.gov) Michele Donato (mdonato@micheledonatoesq.com)

Diane Screnci (diane.screnci@nrc.gov) Neil Sheehan (neil.sheehan@nrc.gov)

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