05000461/LER-2009-003, Re Safety Function Loss Due to No Like for Like Verification of Swapped Relays
| ML093360187 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 11/20/2009 |
| From: | Kearney F Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| SRRS 5A.108, U-603927 LER 09-003-00 | |
| Download: ML093360187 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4612009003R00 - NRC Website | |
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Exeln.
Nuclear Clinton Power Station 8401 Power Road Clinton, IL 61727-9351 10 CFR 50.73 SRRS 5A.108 U-603927 November 20, 2009 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461
Subject:
Licensee Event Report 2009-003-00 Enclosed is Licensee Event Report (LER) No. 2009-003-00: Safety Function Loss Due to No Like for Like Verification of Swapped Relays. This report is being submitted in accordance with the requirements of 10 CFR 50.73 There are no regulatory commitments contained in this letter.
Should you have any questions concerning this report, please contact G. L. Engelhardt, at (217)-937-4435.
Respectflly, F. A. Kearney Site Vice President Clinton Power Station RSF/bIf
Enclosures:
Licensee Event Report 2009-003-00 cc:
Regional Administrator - NRC Region III NRC Senior Resident Inspector - Clinton Power Station Office of Nuclear Facility Safety - IEMA Division of Nuclear Safety
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010 (9-2007)
, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Clinton Power Station, Unit 1 05000461 1 OF 4
- 4. TITLE Safety Function Loss Due to No Like for Like Verification of Swapped Relays
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL I
R FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SENUE REV MONTH DAY YEAR None 05000 I 1 1 I
IFACILITY NAME DOCKET NUMBER 09 24 07 2009 003 -00 11 20 09 None 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
[1 20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
E] 50.73(a)(2)(vii) 1 El 20.2201(d)
[I 20.2203(a)(3)(ii)
[I 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
E] 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii) 0l 50.36(0)(1)(ii)(A)
El 50.73(a)(2)(iv)(A)
[I 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71 (a)(4) 92.4 El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
[E 50.73(a)(2)(v)(B)
El 73.71(a)(5)
El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
[E OTHER El 20.2203(a)(2)(vi)
[E 50.73(a)(2)(i)(B) 0 50.73(a)(2)(v)(D)
Specify in Abstract below or in inspected and found to be functional within the expected resistance band. The damaged resistor and wiring were repaired and the field flash function was tested with satisfactory results.
With relay K-32 in the K-8A position, replacing the 80-second automatic restart relay with a 5-second relay resulted in an inability of the diesel to automatically restart and remain sealed in for approximately 45 seconds (50 seconds for the K-8 shutdown timer minus 5 seconds for relay K-32 being in the K-8A position). Consequently, the diesel would not have been capable of powering the HPCS loads following a LOOP/LOCA signal after manual shutdown of the engine. The diesel generator is analyzed to automatically start and load, energize the HPCS system pump [P] motor [MO], and provide power to initiate opening of the HPCS injection valve [INV] in less than 23 seconds after the LOOP/LOCA initiation signal. Further, the HPCS injection valve would not have opened, and the HPCS pump would not have been at design flow in less than 47 seconds as analyzed after a LOOP/LOCA initiation signal. This issue would not have affected the HPCS safety function if offsite power was available at the time of a LOCA signal.
A review of equipment history identified that relays K-8A and K-32 were pre-calibrated and replaced on 9/24/07 at about 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br /> during the last Division 3 DG maintenance outage. At this time the relays were installed in the wrong locations.
No other inoperable equipment or components directly affected this event.
Issue Report 969157 was initiated to investigate and correct this issue.
CAUSE OF EVENT
The evaluation of this event concluded that the cause of this event was inadequate attention to detail and failure to comply with written instructions.
Maintenance procedures require replacement parts to be compared to the old parts and verified to be like-for-like prior to installation, and allow the use of substitute materials only after the proper evaluation and authorization has been obtained. Further, the supervisor of the work is required to obtain required parts as specified in the work package and ensure the parts are like-for-like or evaluated for use prior to replacement.
The individuals installing the relays in 2007 demonstrated inadequate attention to detail and did not recognize that they were installing relays that had different model numbers from the relays that had been removed. One contractor installed the relays and one utility employee verified the installation. Neither of the individuals involved in installing and verifying the relays recalls the method used to verify the relays were 'like for like' prior to installation. The two relays were pre-calibrated about two weeks prior to installation and tagged for identification and then installed in September 2007 to replace existing installed relays. The individuals that completed the pre-installation calibration of the relays may have entered incorrect identification information on the material tags affixed to the relays; however, the individuals installing the relays have the responsibility to ensure they are installing correct parts.
In each of the work orders used to install these relays in 2007, the technicians recorded the correct serial numbers of the relays in the preparation tasks, but listed the wrong serial numbers in the installation task; however, this discrepancy was not recognized or documented as a deficiency. This discrepancy was reproduced in the electronic work order completion comments for each work order and again not recognized.
The supervisory review of work completion did not catch this discrepancy during closeout review of the work orders.
SAFETY ANALYSIS
This event is reportable under the provisions of 10 CFR 50.73(a)(2)(v)(D) due to a condition that could have prevented fulfillment of the HPCS safety function to mitigate the consequences of an accident.
This event had low safety significance due to the very low probability of a LOOP event occurring during the short duration (45 seconds) of unavailability of the Division 3 DG immediately following each of the 36 times the DG was shut down from surveillance runs while the relays were in swapped locations from 9/24/07 to 9/23/09. During each of the 45-second periods following each of the 36 manual shutdowns of the Division 3 DG during the period the relays were in the swapped locations, offsite power was available. Additionally, a review of the 36 DG runs identified that no events requiring the Division 3 DG and HPCS to perform their LOOP or LOCA functions occurred while the relays were in the swapped positions. Further, following the DG runs while the relays were in the swapped positions, the Reactor Core Isolation Cooling (RCIC) system [BN]
and the other Emergency Core Cooling Systems (ECCS) and their power sources were available to mitigate an accident in the event that a LOOP/LOCA would have occurred.
CORRECTIVE ACTION
Model work orders for time delay relays in the Division 3 DG control panel will be revised to include specific instructions to record "old" and "new" model numbers to reinforce and ensure the correct model is installed and to add a verification job step to compare as-found and as-left model numbers.
A briefing will be provided to the Electrical Maintenance on this event, reinforcing expectations for parts verification and 'like for like' requirements.
Training on parts verification activities will be included in dynamic learning activities for 2010.
PREVIOUS OCCURRENCES
None
COMPONENT FAILURE DATA
No components failed during this event.PRINTED ON RECYCLED PAPERPRINTED ON RECYCLED PAPER