05000336/LER-2006-008, Regarding Scaffold Impairment of Turbine Driven Auxiliary Feedwater Pump Room HELB Blowout Panel
| ML070710222 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 02/19/2007 |
| From: | Jordan A Dominion, Dominion Nuclear Connecticut |
| To: | Document Control Desk, NRC/NRR/ADRO |
| References | |
| 07-0102 LER 06-008-00 | |
| Download: ML070710222 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability |
| 3362006008R00 - NRC Website | |
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Dominion Dominion Nuclear Connecticut, Inc.
Millstone Power Station Rope Ferry Road Waterford, CT 06385 FEB 1 9 2007 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Serial No.
MPS Lic/WEB Docket No.
License No.
07-0102 R0 50-336 DPR-65 DOMINION NUCLEAR CONNECTICUT, INC. (DNC)
MILLSTONE POWER STATION UNIT 2 (MPS2)
LICENSEE EVENT REPORT 2006-008-00 SCAFFOLD IMPAIRMENT OF TURBINE DRIVEN AUXILIARY FEEDWATER PUMP ROOM HELB BLOWOUT PANEL This letter forwards Licensee Event Report (LER) 2006-008-00, documenting an event that occurred at the Millstone Power Station Unit 2 on December 21, 2006.
This LER is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(B) as an operation in a condition prohibited by the plant's Technical Specifications.
Additionally, this condition is being reported pursuant to 10 CFR 50.73(a)(2)(v)(D) as any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident and.
10 CFR 50.73(a)(2)(vii) as a common cause inoperability of independent trains or channels.
If you have any questions or require additional information, please contact Mr. David W. Dodson at (860) 447-1791, extension 2346.
Very truly yours, A. Jd Jordan, Jr.
Plant Manager - Nuclear I--- ý,
Serial No. 07-0102 Licensee Event Report 2006-008-00 Scaffold Impairment of HELB Panel Page 2 of 2 Attachments:
1 Commitments made in this letter: None.
cc:
U.S. Nuclear Regulatory Commission Region I Regional Administrator 475 Allendale Road King of Prussia, PA 19406-1415 Mr. V. Nerses NRC Senior Project Manager Millstone Units 2 and 3 U.S. Nuclear Regulatory Commission, Mail Stop 8 C2 One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 Mr. S. M. Schneider NRC Senior Resident Inspector Millstone Power Station
Serial No. 07-0102 Licensee Event Report 2006-008-00 Scaffold Impairment of HELB Panel MILLSTONE POWER STATION UNIT 2 LICENSEE EVENT REPORT 2006-008-00 Millstone Power Station Unit 2 Dominion Nuclear Connecticut, Inc. (DNC)
Abstract
On December 21, 2006, with the plant in Mode 1 and operating at 100% power, it was identified that scaffolding was erected over the High Energy Line Break (HELB) blowout panel designed for the Turbine Driven Auxiliary Feedwater (TDAFW) pump room. Further investigation identified that the scaffolding was erected on December 11, 2006 and in this configuration, the scaffolding would have restricted the ability of the HELB blowout panel to lift should a HELB event occur. This could have resulted in a breach of the wall separating the TDAFW pump room from the adjacent Motor Driven Auxiliary Feedwater (MDAFW) pump room. The MDAFW pumps are not designed to operate in a steam environment. All three Auxiliary Feedwater (AFW) pumps were declared inoperable on December 21, 2006 at 02:05.
The scaffolding was removed thereby restoring operability of the AFW pumps at 05:27.
The root cause(s) of this event was determined to be a deficiency within the scaffold evaluation process. Specifically, the scaffold process does not provide clear guidance for evaluation, approval and assessment of scaffold installations. It was also identified that there is knowledge deficiency caused by inadequate training and qualification of individuals tasked with implementing the scaffold program.
This is being reported pursuant to 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by the plant's Technical Specifications since the condition existed longer than allowed by Technical Specification 3.7.1.2, 10 CFR 50.73(a)(2)(v)(D) as any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident and 10 CFR 50.73(a)(2)(vii) as a common cause inoperability of independent trains or channels.
NRC FORM 366 (6-2004)
(If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
- 4.
Corrective Action(s) - Immediate Upon discovery, the scaffolding was removed, thus restoring the operability of the auxiliary feedwater pumps.
Corrective Action(s) - To Prevent Recurrence The scaffold evaluation process will be revised to ensure sufficient description of scheduled activities does not interfere with system, structures and components.
The scaffold training program will be evaluated and specific training developed as appropriate to ensure worker knowledge of HELB and other special purpose barriers.
Additional corrective actions are being taken in accordance with the station's corrective action program.
- 5.
Previous Occurrences
Millstone Condition Report CR-05-07367 (July 7, 2005) described a similar condition in the partial restriction of the HELB blowout panel in the TDAFP room due to a security fence installation. Corrective actions for that occurrence were focused on the design control aspects and not the scaffolding process.
LER 2006-006 (October 7, 2006) Scaffolding Built For Work on Main Steam Isolation Valve (2-MS-64A)
Prevented the Valve From Closing. Implementations of compensatory corrective actions from this event were inappropriately delayed and therefore ineffective in preventing a repeat event.
Energy Industry Identification System (EIIS) codes are identified in the text as [XX].