United States Nuclear Regulatory Commission - Protecting People and the Environment

EA-99-138 - Davis-Besse (FirstEnergy Nuclear Operating Company)

August 6, 1999

EA 99-138

Mr. Guy G. Campbell
Vice President - Nuclear, Davis-Besse
FirstEnergy Nuclear Operating Company
Davis-Besse Nuclear Power Station
5501 North State Route 2
Oak Harbor, OH 43449-9760

SUBJECT:  NOTICE OF VIOLATION (NRC INSPECTION REPORT 50-346/98021)

Dear Mr. Campbell:

This refers to the NRC inspection conducted at FirstEnergy's Davis-Besse Nuclear Power Plant from September 1, 1998 to May 13, 1999. The purpose of the inspection was to review the circumstances surrounding your staff's discovery of missing body-to-bonnet nuts on a pressurizer spray valve. The report documenting our inspection was sent to you by letter dated June 4, 1999. NRC inspectors discussed the significance of the issue with members of your staff at the inspection exit meeting on May 13, 1999. Our June 4, 1999, letter offered you the option to either respond to the apparent violation, request a predecisional enforcement conference, or inform the NRC that the information in our inspection report and your Licensee Event Report (LER) 346/98-009 adequately addresses the issue. Your July 1, 1999, letter stated that the inspection report and LER adequately addressed the issue and that you did not request a predecisional enforcement conference.

The NRC determined that two violations of NRC requirements occurred. This determination was based on the: (1) information developed during the inspection; (2) information your staff provided during the inspection; and (3) information your staff documented in LER 346/98-009. The violations involving failure to maintain the design of the valve and inadequate corrective action for the degraded condition are cited in the enclosed Notice of Violation (Notice) and the circumstances surrounding the violations are described in the inspection report.

While monitoring a packing leak on a pressurizer spray valve, a worker identified that one of the eight body-to-bonnet nuts was missing. While your maintenance staff formalized plans to replace the nut, your engineering staff determined that the valve remained functional at design loads with the nut missing. Your maintenance and engineering staff did not do a rigorous evaluation of the cause for the missing nut. Instead they incorrectly determined that a contractor removed the nut to facilitate the installation of equipment for a temporary sealant repair of the packing leak. While replacing the missing nut, a worker identified that a second nut was missing; this nut was also replaced.

During a subsequent outage, a worker noted a gap between one of the replacement nuts and the bonnet. This gap was due to a replacement nut being installed over remnants of a corroded nut. Additionally, a worker found that a third nut was degraded (corroded away) by approximately 30%. A subsequent evaluation determined that three of the nuts were carbon steel and were susceptible to boric acid induced corrosion. The remaining five nuts were stainless steel and were not susceptible to boric acid induced corrosion. An engineering analysis performed by your staff determined that with two nuts missing, safe shutdown earthquake loads concurrent with maximum design pressure would have resulted in failure of the valve's body-to-bonnet joint. The failure would have resulted in a nonisolable reactor coolant system leak (a small break loss of coolant accident) at the failed joint. A subsequent vendor analysis concluded that the valve would have remained functional under all accident conditions.

In your July 1, 1999, letter, you stated that: (1) your staff complied with industry guidance for degraded and nonconforming conditions; (2) a detailed evaluation demonstrated the reactor coolant system was operable; and (3) that there was no regulatory significance due to the lack of safety, or environmental consequence. The NRC acknowledged that the as-found condition may not have had actual safety, or environmental consequence. Additionally, we acknowledge that each time a missing nut was found your staff attempted to restore the valve to a safe configuration. However, your staff failed to do a rigorous evaluation of the missing nuts in a timely manner, which resulted in delays in: (1) identifying that carbon steel nuts were installed, contrary to the design specifications of the valve; (2) determining that the missing carbon steel nuts had corroded due to a highly corrosive boric acid environment; (3) initiating actions to identify the extent of the degraded condition; and (4) implementing more extensive corrective actions to address the degraded and nonconforming condition. Additionally, your maintenance staff missed another opportunity to identify the corrosion problem when they placed a nut on a remnant of a nut that was believed missing. A detailed evaluation of the degraded condition by the vendor was required to demonstrate that the valve would have remained functional under all conditions. The NRC has concluded that your staff's failure to control the design of a reactor coolant system pressure boundary component and to thoroughly evaluate and correct degraded conditions in a timely manner did have a credible potential to impact plant safety. Therefore, the violations are categorized in the aggregate in accordance with the "General Statement of Policy and Procedure for NRC Enforcement Actions (Enforcement Policy)," NUREG-1600, as a Severity Level III problem.

In accordance with the Enforcement Policy, a base civil penalty in the amount of $55,000 was considered for this Severity Level III problem. Because your facility has not been the subject of escalated enforcement actions within the last two years, the NRC considered whether credit was warranted for Corrective Action in accordance with the civil penalty assessment process in Section VI.B.2 of the Enforcement Policy. You were given credit for initiating effective corrective actions once you identified the root cause of the degradation. Your corrective actions included: (1) training sessions with maintenance personnel to enhance knowledge of the effects of boric acid on materials; (2) a review of boric acid corrosion procedures which resulted in program enhancements; (3) the inspection of pressure retaining bolted connections with a potential for the installation of fasteners of nonconforming material; and (4) resolution of the pressurizer spray valve packing problems.

Therefore, to acknowledge your comprehensive correction of the violations, I have been authorized, after consultation with the Director, Office of Enforcement, not to propose a civil penalty in this case. However, significant violations in the future could result in a civil penalty.

The NRC has concluded that information regarding the reason for this violation; the date when you will achieve full compliance; and the corrective actions taken to correct the violation and prevent recurrence are already adequately addressed on the docket in Inspection Report 50-346/98021 and LER 346/98-009. Therefore, you are not required to respond to this letter unless the description therein does not accurately reflect your corrective actions or your position. In that case, or if you choose to provide additional information, please follow the instructions specified in the enclosed Notice.

In accordance with 10 CFR 2.790 of the NRC's "Rules of Practice," a copy of this letter and the enclosure will be placed in the NRC Public Document Room.



Sincerely,
ORIGINAL SIGNED BY J. E. DYER

J. E. Dyer
Regional Administrator

Docket No. 50-346
License No. NPF-3

Enclosure: Notice of Violation

cc w/encl:
J. Stetz, Senior Vice President - Nuclear
J. Lash, Plant Manager
J. Freels, Manager, Regulatory Affairs
M. O'Reilly, FirstEnergy
State Liaison Officer, State of Ohio
R. Owen, Ohio Department of Health
C. Glazer, Chairman, Ohio Public
   Utilities Commission


NOTICE OF VIOLATION

 
FirstEnergy Nuclear Operating Company Davis-Besse   Docket No. 50-346
License No. NPF-3
EA 99-138

During an NRC inspection conducted from September 1, 1998 to May 13, 1999, two violations of NRC requirements were identified. In accordance with the "General Statement of Policy and Procedure for NRC Enforcement Actions," NUREG-1600, the violations are listed below:

1.   10 CFR Part 50, Appendix B, Criterion III, "Design Control," states, in part, that design changes, including field changes, shall be subject to design control measures commensurate with those applied to the original design and be approved by the organization that performed the original design unless the applicant designates another responsible organization.

Pressurizer Spray Valve RC-2 is a safety-related plant component that is subject to the requirements of 10 CFR Part 50. Drawing number M-525-3-7, specified a portion of the design requirements of Pressurizer Spray Valve RC-2 in that the body-to-bonnet nuts are to be stainless steel.

Contrary to the above, prior to September 1, 1998, the licensee inadvertently performed a field change to Pressurizer Spray Valve RC-2, that was not approved by the organization that performed the original design or by any other organization. This inadvertent field change replaced three of eight boric acid corrosion resistant body-to-bonnet stainless steel nuts with boric acid corrosion susceptible carbon steel nuts. These nuts, in the presence of an aggressive corrosive environment, degraded to the point where 30% of one nut and essentially all of two other nuts had corroded away. (01013)

2.   10 CFR Part 50, Appendix B, Criterion XVI, "Corrective Actions," states, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances, are promptly identified and corrected.

Contrary to the above, on September 1, 1998, the licensee failed to promptly identify and correct a condition adverse to quality. Specifically, workers discovered that a body-to-bonnet nut was missing on RC-2, "Pressurizer Spray Valve," but failed to identify that a second nut was also missing. Additionally the licensee did not do a rigorous evaluation to eliminate boric acid induced corrosion of carbon steel fasteners as a root cause. They incorrectly concluded that a contractor removed the nut to facilitate a temporary sealant repair of the packing leak. The failure to do an extensive evaluation of the condition resulted in the incomplete installation of a replacement nut on the remnants of a corroded nut, and the missed opportunity for early detection of the second missing nut and a third nut that was degraded by 30%. (01023)

This is a Severity Level III problem (Supplement 1).

The NRC has concluded that information regarding the reason for the violation, the corrective actions taken and planned to correct the violation and prevent recurrence and the date when full compliance will be achieved is already adequately addressed on the docket in Inspection Report 50-346/98021 and LER 346/98-009. However, you are required to submit a written statement or explanation pursuant to 10 CFR 2.201 if the description therein does not accurately reflect your corrective actions or your position. In that case, or if you choose to respond, clearly mark your response as a "Reply to a Notice of Violation," and send it to the U.S. Nuclear Regulatory Commission, ATTN:  Document Control Desk, Washington, DC 20555 with a copy to the Regional Administrator, Region III, and a copy to the NRC Resident Inspector at the facility that is the subject of this Notice, within 30 days of the date of the letter transmitting this Notice of Violation (Notice).

If you contest this enforcement action, you should also provide a copy of your response, with the basis for your denial, to the Director, Office of Enforcement, United States Nuclear Regulatory Commission, Washington, DC 20555-0001.

If you choose to respond, your response will be placed in the NRC Public Document Room (PDR). Therefore, to the extent possible, the response should not include any personal privacy, proprietary, or safeguards information so that it can be placed in the PDR without redaction.

In accordance with 10 CFR 19.11, you may be required to post this Notice within two working days.

Dated this 6th day of August 1999

Page Last Reviewed/Updated Thursday, March 29, 2012