ML070440039
| ML070440039 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 03/16/2007 |
| From: | Reyes L NRC/EDO |
| To: | Saxton J US HR (House of Representatives) |
| AYALA, JUAN, NRR/DLR/RLRA, 415-4063 | |
| References | |
| G20070092, LTR-07-0087, TAC MD4247 | |
| Download: ML070440039 (3) | |
Text
March 16, 2007 The Honorable Jim Saxton United States House of Representatives Washington, DC 20515
Dear Congressman Saxton:
On behalf of the U.S. Nuclear Regulatory Commission (NRC), I am responding to your letter dated January 30, 2007, in which you identify concerns related to the safe operation of the Oyster Creek Nuclear Generating Station (Oyster Creek). Your letter, quotes a January 23, 2007 editorial in the Asbury Park Press, in which a manager at Oyster Creek states that the spent fuel pool had some issues with corroded rebar, which are metal bars that reinforce the concrete.
NRC is aware of the statements quoted in the editorial. They were made during a Plant Operations Review Committee (PORC) meeting for the review of the license renewal application (LRA) on May 24, 2005. NRC requires nuclear power plants to establish a PORC to review technical issues related to plant operations. These meetings are held periodically, and in fact, at a subsequent PORC meeting on June 14, 2005, Amergen Energy Company, LLC (Amergen), clarified that the corroded rebar was not in the spent fuel pool, as initially stated, but in the equipment pool and reactor cavity walls.
The NRC has been monitoring this issue since 1986, when GPU Nuclear Corporation (GPU),
the former owner of Oyster Creek, identified water and rust stains around hairline cracks on the exterior surface of the equipment pool and reactor cavity walls. GPU took corrective actions, which the NRC resident inspector monitored, including sampling the concrete to determine whether water intrusion into the cracks created an aggressively corrosive environment to the rebar. Based on the results of the corrosion test, GPU concluded that the environment was non-aggressive and would cause minimal rebar corrosion.
On December 5, 1990, GPU provided NRC more information regarding the corroded rebar identified in the equipment pool and reactor cavity walls and provided an analysis of the issue and corrective actions taken. The information included a comprehensive analysis of the maximum stress capacity of the corrosion-affected rebar. The report indicated that for load combinations involving operating and seismic loads the maximum calculated stress remains below the American Concrete Institute yield-stress limits.
The NRC reviewed GPUs conclusion that rebar corrosion was minimal and that the equipment pool and reactor cavity walls would be able to perform their intended functions. The NRC staff issued a safety evaluation on May 11, 1994, and agreed with GPUs conclusions. As part of the safety evaluation, the NRC recommended that GPU periodically monitor the condition of the equipment pool and reactor cavity walls.
J. Saxton Amergen has conducted periodic inspections of the equipment pool walls and the reactor cavity since the mid-1990s and there have been no indications of water intrusion or further deterioration. NRC reviewed the Amergen inspections as part of our reactor oversight process and again during the LRA review process.
AmerGens inspections and analysis determined that the corrosion was due to leakage from cracks in the stainless steel liner of the equipment pool walls and reactor cavity, when they are filled with water during refueling outages. AmerGen has applied a strippable coating prior to filling the equipment pool and reactor cavity during the refueling outages since identifying the problem, which has minimized water leakage. The licensee has committed to applying this strippable coating during every refueling outage.
The NRC published the results of its review of the LRA, including AmerGens commitments, in a safety evaluation report issued on December 29, 2006, which is publicly available through the NRC website. The Advisory Committee on Reactor Safeguards, an independent review committee, reviewed the LRA and the staffs evaluation of the LRA, and recommended renewal of the Oyster Creek operating license in a letter dated February 8, 2007. In addition, AmerGen committed to perform an engineering study to investigate cost-effective replacement or repair options to eliminate or reduce reactor cavity liner leakage in a letter dated February 15, 2007.
I appreciate your interest in the safety of the Oyster Creek power station. Please contact me if I can be of further assistance.
Sincerely,
/RA/
Luis A. Reyes Executive Director for Operations
Pkg: ML070440049; Incoming: ML070380481; Response: ML070440039
- via email OFFICE PM:RLRA:DLR LA:RLRA:DLR Tech Editor OGC nlo (A)BC:RLRA:DLR NAME JAyala*
YEdmonds HChang*
SHamrick RSchaaf DATE 03/01/07 02/23/07 02/21/07 03/01/07 03/02/07 OFFICE D:DLR D:NRR OCA EDO NAME PKuo JDyer BKeeling LReyes DATE 03/02/07 03/06/07 03/16/07 03/16/07