05000311/LER-2009-002, Regarding 22 Component Cooling Heat Exchanger Inoperable for Greater than Allowed Outage Time
| ML093580095 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 12/15/2009 |
| From: | Braun R Public Service Enterprise Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LR-N09- 0287 LER 09-002-00 | |
| Download: ML093580095 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 3112009002R00 - NRC Website | |
text
PSEG Nuclear LLC P.O. Box 236,, Hahcocks Bridge, NJ 08038-0236 0 PSEG Nuclear L.L. C.
DEC 1 5 2009 10CFR50.73 LR-N09- 0287 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington DC 20555-001 LER 311/09-002 Salem Nuclear Generating Station Unit 2 Facility,0perating License No. DPR-75 NRC Docket No. 50-311
SUBJECT:
22 Component Cooling Heat Exchanger Inoperable for Greater Than Allowed 'Outage Time This Licensee Event Report; "22 Component Cooling Heat Exchanger Inoperable for Greater Than Allowed. Outage Time," is being submitted pursuant to the requirements of the Code of Federal Regulations 10CFR50.73 (a)(2)(i)(B), "any operation... prohib.ited'by the plant's Technical Specification."
The attached LER contains no commitments. Should you have any questions or comments regarding this submittal, please contact Mr. Brian Thomas at 856-339-2022.
Sincerely, Robert Braun Site Vice President - Salem Attachments (1)
Document Control Desk DEC 1 5 2009 Page 2 LR-N09- 0287 cc Mr. S. Collins, Administrator, Region I, NRC Mr. R. Ennis, Licensing Project Manager - Salem, NRC Mr. D. Schroeder, USNRC Senior Resident Inspector, Salem (X24)
Mr. P. Mulligan, Manager IV, NJBNE L. Marabella, Corporate Commitment Tracking Coordinator H. Berrick, Salem Commitment Tracking Coordinator
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010 19-2007)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Salem Generating Station - Unit 2 05000311 1 of 5
- 4. TITLE 22 Component Cooling Heat Exchanger Inoperable for Greater Than Allowed Outage Time
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE I
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR SEQUENTIAL REV MONTH DAY YEAR YEA YAR NUMBER NO.
DOCKET NUMBER 10 17 2009 20090 0 20 12 15 2009[DCE NME
- 9.
OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)
El 20.2201(b)
[I 20.2203(a)(3)(i)
[I 50.73(a)(2)(i)(C)
Rl 50.73(a)(2)(vii) 6 0 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A) nl 50.73(a)(2)(viii)(A) 0l 20.2203(a)(1)
El 20.2203(a)(4)
[I 50.73(a)(2)(ii)(B)
[3 50.73(a)(2)(viii)(B) 0E 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
[I 50.73(a)(2)(iii) 17 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
El 50.36(c)(2) 1771 50.73(a)(2)(v)(A)
El 73.71(a)(4)
El 20.2203(a)(2)(iv) 0l 50.46(a)(3)(ii)
[I 50.73(a)(2)(v)(B)
El 73.71(a)(5) 0 El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C).
1 E-OTHER El 20.2203(a)(2)(vi)
D 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in DESCRIPTION OF OCCURRENCE (cont'd)
It has been determined that since valve 22SW356 gear box mounting bolts failed after operation at 9500 gpm of service water flow during the outage, a similar failure could have occurred during post-LOCA conditions. Since the 22 CC HX was not able to perform its design basis post-LOCA heat removal function during the past operating cycle, the 22 CC HX was inoperable for greater than the allowed outage time of TS 3.7.3.
This report is being made in accordance with 10CFR50.73 (a)(2)(i)(B), "any operation... prohibited by the plant's Technical Specification."
CAUSE OF OCCURRENCE The gear box for the 22SW356 valve failed to the partially open position when all four (4) gear box-to-valve mounting bolts failed. Based on examination and lab analysis, the bolts failed due to lateral impact loads. The bolt failures are attributed to installing improper low strength bolts in April 2002 since the correct bolts were not specified in the work order. The lower strength bolts did not retain the preload allowing the bolts to loosen during high flow conditions when system vibration was elevated. In addition, the installation procedure that was created in 1996 did not include a torque value for the manual operator in use (MTD-4S). The procedure provided a torque value for a similar manual operator (MTD-4). This value was lower than the torque specified by the vendor for MTD-4S.
PREVIOUS OCCURRENCES
A review of LERs for Salem Units 1 and 2 for the previous three years did not identify any previous
similar events
SAFETY CONSEQUENCES AND IMPLICATIONS
The 22 CC HX manual outlet valve 22SW356 failed to a partially open position on October 17, 2009. Salem Unit 2 was shutdown on October 13, 2009 to begin the seventeenth refueling outage (2R17) and Mode 5 was entered on October 14, 2009 at 0430 hours0.00498 days <br />0.119 hours <br />7.109788e-4 weeks <br />1.63615e-4 months <br />. At 0459 hours0.00531 days <br />0.128 hours <br />7.589286e-4 weeks <br />1.746495e-4 months <br />, the 22 CC HX was placed in service with 9500 gpm service water flow to support both trains of RHR and removal of the 21 CC HX to support outage maintenance activities. On October 16, 2009 at 1703 hours0.0197 days <br />0.473 hours <br />0.00282 weeks <br />6.479915e-4 months <br />, Salem Unit 2 entered Mode 6 and the reactor head was fully de-tensioned at 2355 hours0.0273 days <br />0.654 hours <br />0.00389 weeks <br />8.960775e-4 months <br />. On October 17, 2009 at 0603 hours0.00698 days <br />0.168 hours <br />9.970238e-4 weeks <br />2.294415e-4 months <br />, operators reported from the field that the gear box for valve 22SW356 had shifted and that flow through the 22 CC HX was reading approximately 3200 gpm. Operators entered Technical Specification (TS) 3.9.8.2 for two loops of RHR not being operable. At 0658 hours0.00762 days <br />0.183 hours <br />0.00109 weeks <br />2.50369e-4 months <br />, the 22SW356 valve was secured in position to prevent the valve from going closed any further. Service water flow through the 22 CC HX was approximately 3400 gpm. At 0753 hours0.00872 days <br />0.209 hours <br />0.00125 weeks <br />2.865165e-4 months <br />, operators verified the ability of the 22 CC HX to provide adequate core cooling by adjusting the RHR HX outlet control valves. RCS temperature reduced from 125.6 OF to 124.5 OF. At 0818 hours0.00947 days <br />0.227 hours <br />0.00135 weeks <br />3.11249e-4 months <br />, service water flow was established to the 21 CC HX and a RCS temperature decrease was observed. Conservatively, the control room operators did not exit TS 3.9.8.2 until the 21 CC HX was configured to support both trains of RHR with one service water header out of service. Although there was a reduction in service water flow through the 22 CC HX, the capability to remove core decay heat during shutdown conditions was maintained as demonstrated by the ability to reduce RCS temperature through the manipulation of the RHR HX outlet control valves.
It has been determined that since valve 22SW356 gear box mounting bolts failed after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of operation at 9500 gpm during the outage, a similar failure could-have occurred during post-LOCA conditions. For the majority of the previous operating cycle, the 21 CC HX was available and capable of providing post-LOCA heat removal. The 21 CC HX was inoperable for three periods during the previous operating cycle -
December 2008 for - 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br />; January 2009 for -11.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />; February 2009 for - 44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br />. During these periods, the maximum calculated post-LOCA flow demand was approximately 6800 gpm and since the system vibration would have been considerably lower there is reasonable assurance that the 22SW356 valve gear box mounting bolts would not have failed. During these periods, the 22 CC HX was therefore capable of performing its design basis heat removal function.
A review of this event determined that a Safety System Functional Failure (SSFF) as defined in NEI 99-02, Regulatory Assessment Performance Indicator Guidelines, did not occur since the ability to remove residual heat and mitigate the consequences of an accident were maintained as described above.
CORRECTIVE ACTIONS
- 1. The 22SW356 valve and gearbox were replaced using the correct mounting bolts. The bolts were torqued to the correct values.
- 2. A roll-out of the work order deficiencies was conducted with the appropriate maintenance and planning personnel. This roll-out included a discussion on the use of proper bolts listed on the bill of materials.
- 3. The maintenance procedure for the manual valve operator has been placed on hold to prevent use of the procedure until revised to include the proper torque acceptance criteria for the mounting bolts.
- 4. New preventive maintenance items will be created for valves 11SW121 (11 CC HX inlet valve), 11 SW355 (11 CC HX outlet valve), 21 SW1 21 (21 CC HX inlet valve), 21 SW355 (21 CC HX outlet valve), 22SW121 (22 CC HX inlet valve), and 22SW356 (22 CC HX outlet valve) to include removing the mounting bolts to inspect for damage, proper bolt material, inspection of bolt holes and reinstallation in accordance with procedure SC.MD-PM.ZZ-0167.
The above actions are being tracked in PSEG's corrective action program.
COMMITMENTS
No commitments are made in this LER.