RC-05-0034, Response to Preliminary White Finding, NRC Inspection Report 2005006, Apparent Violation AV 05000395/2005006-02
| ML13295A423 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 02/23/2005 |
| From: | Archie J South Carolina Electric & Gas Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| IR-05-006, RC-05-0034 | |
| Download: ML13295A423 (4) | |
Text
Jeffrey B. Archie Vice President,Nuclear Operations
___________ _ 803.345.4214 A SCANA COMPANY February 23, 2005 RC-05-0034 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Dear Sir / Madam:
Subject:
VIRGIL C. SUMMER NUCLEAR STATION (VCSNS)
DOCKET NO. 50/395 OPERATING LICENSE NO. NPF-12 RESPONSE TO PRELIMINARY WHITE FINDING NRC INSPECTION REPORT 2005006 APPARENT VIOLATION AV 0500039512005006-02 On January 14, 2005, the U.S. Nuclear Regulatory Commission (NRC) issued NRC Inspection Report 05000395/2005006 to South Carolina Electric and Gas Company (SCE&G) announcing a preliminary White Finding resulting from an assessment of Unresolved Item (URI)0500395/2004009-01 identified in Section 40A5.2.1 of NRC Inspection Report 05000395/2004009 issued on December 22, 2004. Two apparent violations (AV) of 10 CFR 50, Appendix B were identified regarding this finding and were identified in Inspection Report 05000395/2005006. The first was an apparent violation of Criterion Ill, Design Control, and the second was of Criterion XVI, Inadequate Corrective Action, both involving a perceived inadequacy in corrective actions associated with a deficiency in the design of the Emergency Feedwater (EFW) system flow control valves at VC Summer Nuclear Station (VCSNS).
SCE&G provided additional information to the NRC in a February 9, 2005 letter and subsequently met with the NRC in a Regulatory Conference to discuss the above issues on February 17, 2005.
Design Control This item involved an old design issue regarding how the EFW flow control valves were originally specified. It was noted during the Regulatory Conference that the February 9, 2005 letter included additional information related to the apparent violation of Criterion Ill, Design Control. VCSNS considers the valves were properly specified at that time.
SCE&G I Virgil C.Summer Nuclear Station
- P.O.Box 88 Jenkinsville, South Carolina 29065 .T (803) 345.5209. www.scana.com
Document Control Desk letter C-05-0116 RC-05-0034 Page 2 of 4 Corrective Action At the Regulatory Conference, SCE&G presented to the NRC plant-specific information on several issues raised in the subject inspection reports. This information provided a more accurate and applicable significance determination regarding the as-found EFW design. During the meeting, the NRC inquired if VCSNS would be submitting any information in response to the second apparent violation, that involving Criterion XVI, Inadequate Corrective Action. This letter provides that information.
The issues associated with the potential for fouling of the EFW flow control valves due to swap-over to the SW system have been an evolutionary process for SCE&G since at least 1986 when our ISEG group questioned the existing plant design. The results of the evaluations and the directions taken in the resolution of issues involved VCSNS management including the site vice president. Since that time the issue has been raised several times in response to in-house review, the issuance of new industry operating experience, and NRC questions. Over time, as the design and functionality of the system has been questioned, the basic premise that the system and components associated with the swap-over are designed and maintained appropriately has been upheld.
While changes to the inspection and maintenance requirements have been incorporated over the years, these corrective actions have been based on new or additional information which has been reviewed for applicability to our particular needs at the time. The requirements for inspection of the cross connect piping and any additional associated corrective actions deemed necessary have been an element of the program since the 4th refueling outage. While enhancements to the program have been reviewed and considered for years, the fact that changes are made does not indicate that the existing program was insufficient or ineffective, but that additional actions may be prudent due to new information (new OE, provide additional supporting information, new regulatory requirements, etc.).
The nature of the fouling found in the cross-connect piping has been tubercular in nature and very typical of that found in no flow piping conditions. Samples obtained from the SW intake screen are not generally friable and are not typical of tubercles in the piping itself. Our experience with inspections indicate that the actual tubercles adhere tenaciously to the pipe wall and that very little would be expected to be released by normal EFW flow rates. It is expected that any tubercular material that is dislodged would be easily pulverized in the EFW pumps and would subsequently pass through the flow control valves. Even if a small amount of material were to become dislodged and pass through the pump and remain on the valve cage, the flow control valves can maintain design basis flow with plugging levels up to 68%.
Document Control Desk letter C-05-0116 RC-05-0034 Page 3 of 4 The internal condition of the EFW to SW cross connect piping has been assessed programmatically by the performance of periodic inspections.
Engineering review of the inspection results have resulted in further corrective actions on several occasions. Cleaning to remove silt and tubercular growth has been a supplementary corrective action implemented on several occasions.
Adjustments to the inspection frequency have been based on inspection results and industry operating experience. For example, work documents were created to clean the piping based on industry operating experience. This was done prior to the NRC's Design Margin Inspection. The extent and detail of the inspections have also been revised over time to address the concerns raised by both internal and external events. While the inspection specifics have changed over the years based on various circumstances, the need to inspect the piping to assess the system's ability to perform its design functions has been the basis for the activity.
During the course of the NRC inspection, SCE&G compiled a timeline of the activities associated with the issue of EFW flow control valve blockage.
(Attachment VIII to CER 04-3416). Based on the above discussion and a re-review of this timeline, SCE&G maintains the corrective actions that have been evaluated and implemented to address the issue have been appropriate and timely. While improvements to the program are currently being evaluated, and additional corrective actions are being pursued to further address industry and NRC staff concerns, these provisions are considered to be enhancements and not the result of ineffective corrective actions. SCE&G maintains that VCSNS activities concerning the EFW to SW cross connect piping function capability have not been inadequate.
Conclusion This additional supporting information, in combination with information provided in the February 9, 2005 letter, and the material presented at the February 17, 2005 presentation to the NRC, should provide the NRC with adequate basis to allow for reconsidering the issuance of both the Criterion III and the Criterion XVI violations.
As previously noted in our pre-conference documentation submitted on February 9, 2005 and again at the conference, notwithstanding the final safety significance ranking of this matter by the NRC, SCE&G is committed to taking appropriate corrective actions regarding the design and performance of the EFW system.
Document Control Desk letter C-05-0116 RC-05-0034 Page 4 of 4 If the NRC has questions that do not appear to be addressed by this submittal, please do not hesitate to call Ron Clary at (803) 345-4757.
Very tr I -yours, J rey B. Archie AMM/JBA/mb c: C. R. Ogle N. 0. Lorick S. A. Byrne N. S. Cams T. G. Eppink R. J. White W. D. Travers K. R. Cotton NRC Resident Inspector Winston & Strawn General Managers Managers NSRC CER (C-05-0116)
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