ML022390624
| ML022390624 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 08/23/2002 |
| From: | Office of Nuclear Reactor Regulation |
| To: | General Electric Co |
| References | |
| Download: ML022390624 (5) | |
Text
U.S. Nuclear Regulatory Commission Operations Center Event Report General Information or Other (PAR)
Event#
39148 Rep Org: GENERAL ELECTRIC COMPANY Notification Date I Time: 08/23/2002 15:45 (EDT)
Supplier: GE NUCLEAR ENERGY Event Date I Time: 08/23/2002 (PDT)
Last Modification: 08/23/2002 Region: 4 Docket #:
City: SAN JOSE Agreement State: Yes County:
License #:
State: CA NRC Notified by: JASON POST Notifications: WILLIAM JOHNSON R4 HQ Ops Officer: FANGIE JONES KEN BARR R2 Emergency Class: NON EMERGENCY VERN HODGE - FAX NRR 10 CFR Section:
21.21 UNSPECIFIED PARAGRAPH 10 CFR 21 REPORT: MAIN STEAM LINE OUT-OF-SERVICE The following is taken from a facsimile report:
"This letter provides notification of a Reportable Condition under IOCFR 21.21(d) and as an interim report per
§21.21.(a)(2) for other plants that may be determined to be affected. The basis for this conclusion is that a 1988 GE Nuclear Energy (GE) analysis for Brunswick Units 1 and 2 full power operation with one Main Steamline Isolation Valve (MSIV) Out of Service (OOS) provided to Carolina Power and Light (CP&L) did not adequately address the increased flow induced vibratory loads on the MSIVs to assure they would be able to perform their required safety function which could result in potential offsite exposures in excess of those in 10CFR100.11.
"The GE MSIV OOS analysis evaluated plant operation at 100% power with three active steamlines and one set of MSIVs closed (OOS). The GE analysis did not address the increased steam flow hardware effect of potential long term flow induced vibration degradation on the MSIVs, including the effect on the MSIV air operated controls.
During three steamline operation the steam flow in each line would increase to approximately 133% of normal flow.
No vibration measurements (empirical or experimental data) exist for either Brunswick Units during operation up to this increased steam flow level.
"If it is postulated that the plant operated for an extended period in the MSIV OOS condition and then a main steam line break is postulated to occur in one of the three operational steam lines, then there is the potential that neither MSIV would close to terminate the release from a steamline break. Because GE has no analytical or experience basis (no available empirical or experimental data) to support higher main steam line flow rates greater than previously tested, it could be postulated that a common mode failure of both MSIVs, in the broken line, could occur. Alternatively, failure of one MSIV due to the high flow induced vibration and the other MSIV as the design basis single failure, would result in an un-terminated release, which would exceed the existing 10 CFR 100 radiation release limits.
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08/23/2002 U.S. Nuclear Regulatory Commission Operations Center Event Report Page2 General Information or Other (PAR)
Event#
39148 "GE has verbally communicated to CP&L the need for the 75% power limitation when exercising the MSIV OOS flexibility and will follow-up with a written communication "GE is reviewing all other MSIV OOS analyses performed by GE for other BWRs and will communicate to any similarly affected utilities, similar corrective actions GE will notify all affected utilities that GE recommends operation at the 75% power level when operating with one MSIV 005, unless there is sufficient test data to support operation at a higher power level. This effort will be completed by September 30, 2002."
GE Nuclear Energy Ginera/ £lectric Compony 175 CurmnerAvc., San Jose, CA 95125 August 23, 2002 02-05NRC.DOC MFN 02-049 Document Control Desk United States Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738
Subject:
Main Steam Line Valve Out-of-Service This letter provides notification of a Reportable Condition under IOCFR 21.21(d) and as an interim report per §21.21.(a)(2) for other plants that may be determined to be affected.
The basis for this conclusion is thai a 1988 GE Nuclear Energy (GE) analysis for Brunswick Units 1 and 2 full power operation with one Main Steamline Isolation Valve (MSIV) Out of Service (OOS) provided to Carolina Power and Light (CP&L) did not adequately address the increased flow induced vibratory loads on the MSIVs to assure they would be able to perform their required safety function which could result in potential offsite exposures in excess of those in 10CFR1 00.11.
If you have any questions, please call me at (408) 925-5362.
Sincerely, Auaad4'1ýfor Jason. S. Post, Manager Engineering Quality and Safety Evaluations cc: S. D. Alexander (NRC-NRR/DISPIPSIB) Mail Stop 6 F2 G. C. Cwalina (NRC-NRR/DISP/PSIB) Mail Stop 6 F2 J. F. Klapproth (GE-NE)
H. J. Neems (GE-NE)
PRC File
Attachment:
- 1. Reportable Condition Evaluation per §21.21(d) 1T "9v'd S15i6d dO'A 3N3D O693G66T9 LE:GT ZOOZ/EZ/80
Attachment. I - Reportable Condition per §21.21 (d)
(i)
Name and address of the individual informing the Commission:
Jason S. Post, Manager, Engineering Quality & Safety Evaluation, GE Nuclear Energy, 175 Curtner Avenue, San Jose, CA 95125 (ii)
Identification of the facility, the activity, or the basic component supplied for such facility or such activity within the United States which fails to comply or contains a defect:
The Main Steam Line Valve Out-of-Service analysis for Brunswick Units I and 2.
(iii)
Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect:
GE Nuclear Energy, San Jose, California (iv)
Nature of the defect or failure to comply and safety hazard which is created or could be created by such defect or failure to comply:
The GE MSIV OOS analysis evaluated plant operation at 100% power with three active steamlines and one set of MSIVs closed (OOS). The GE analysis did not address the increased steam flow hardware effect of potential long-term flow induced vibration degradation on the MSIVs, including the effect on the MSIV air operated controls. During three steamline operation the steam flow in each line would increase to approximately 133% of normal flow.
No vibration measurements (empirical or experimental data) exist for either Brunswick Units during operation up to this increased steam flow level.
If it is postulated that the plant operated for an extended period in the MSIV OSS condition and then a main steam line break is postulated to occur in one of the three operational steam lines, then there is the potential that neither MSTV would close to terminate the release from a steamline break.
Because GE has no analytical or experience basis (no available empirical or experimental data) to support higher main steamnline flow rates greater than previously tested, it could be postulated that a common mode failure of both MSIVs, in the broken line, could occur. Alternatively, failure of one MSIV due to the high flow induced vibration and the other MSIV as the design basis single failure, would result in an un-terminated release, which would exceed the existing 10 CFR 100 radiation release limits.
(v)
The date on which the information of such defect or failure to comply was obtained:
June 24, 2002 2
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(vi)
In the case of a basic component which contains a defect or failure to comply, the number and locations of all such components in use at, supplied for, or being supplied for one or more facilities or activities subject to the regulationm in this part:
A defect has been confirmed to exist at Brunswick Units 1 and 2.
(vii)
The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action (note, these are actions specifically associated with the identified Reportable Condition):
GE has verbally communicated to CP&L the need for the 75% power limitation when exercising the MSIV OOS flexibility and will follow-up with a written communication.
GE is reviewing all other MSIV OOS analyses performed by GE for other BW'Rs and will communicate to any similarly affected utilities, similar corrective actions.
GE will notify all affected utilities that GE recommends operation at the 75%
power level when operating with one MSIV OOS, unless there is sufficient test data to support operation at a higher power level. This effort will be completed by September 30, 2002.
GE has initiated a review of recent power uprate projects for proper inclusion and evaluation of other limiting configurations/conditions.
This effort will be completed by September 16, 2002.
GE is reviewing and will revise existing internal engineering and program processes to explicitly screen any limiting configurations/conditions for current and future evaluations.
(viii)
Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, ore will be given to purchasers or licensees:
GE recommends operation at the 75% power level when operating with one MSIV OOS, unless there is sufficient test data to support operation at a higher power level.
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