05000255/LER-2007-010, Technical Specification Action Requirements Not Met for Battery Cell Parameter Outside Allowable Limits
| ML080590592 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 02/21/2008 |
| From: | Schwarz C Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 07-010-00 | |
| Download: ML080590592 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2552007010R00 - NRC Website | |
text
Entergy Nuclear Operations, Inc.
Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043 Tel269 764 2000 February 21, 2008 10 CFR 5OS73(a)(2)(i)(B)
U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Palisades Nuclear Plant Docket 50-255 License No. DPR-20 Licensee Event Report 07-01 0, Technical Specification Action Requirements Not Met for Battery Cell Parameter Outsid-e-Allowable Limits
Dear Sir or Madam:
Licensee Event Report (LER)07-010 is enclosed. The LER describes the failure to recognize that a battery cell parameter was not within Technical Specification (TS) limits. As a result, the associated TS action requirements were not met. The occurrence is reportable in accordance with 10 CFR 50.73(a)(Z)(i)(B).
Summary of Commitments This letter contains no new commitments and no revisions to existing commitments.
Christopher J. Schwarz Site Vice President Palisades Nuclear Plant Enclosure (1 )
CC Administrator, Region Ill, USNRC Project Manager, Palisades, USNRC Resident Inspector, Palisades, USNRC
ENCLOSURE 1 LER 07- 01 0 Technical Specification Action Requirements Not Met for Battery Cell Parameter Outside Allowable Limits 3 Pages Follow
Estlmafed burden per response to comply mth PIIS rn Pours. Peporled lessons learned are 8nccrponted t
LICENSEE EVENT REPORT (LER) 50.73(a)(2)(11)(A) 50m73(a)(2)(vlii)(A) a 50,73(a)(Z)(ii)(B) 50.73(a)(2){viii)(8) 50.73(a)(2)(ix)(A) 20.2203IaH2)liv) 23 50,16(a)f3)(ii) 20.2203(rl)t2)!vl 50a73(a)(2)(i)(A) battery was found to be below the allowable TS limit for this parameter. However, at the time of this discovery, it was not recognized that the parameter was actually below the specified TS battery cell limit. Subsequently, on December 28, 2007, during review of the surveillance data and discussion with members of the electrical maintenance department who had performed the surveillance, an on-duty senior reactor operator recognized the tow reading for battery cell 43.
The delay of over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in recognizing that battery cell 43 float voltage was below the TS limit for this parameter resulted in not meeting the TS completion time for required actions in accordance with TS 3.8.6.A and TS 3.8.6.8, that were applicabte from the initial discovery time.
The failure of the electrical maintenance crew to initially recognize that the battery cell 43 voltage was below the TS limit was attributed to an inadequate pre-job brief. Pre-job brief performance expectations will be re-iterated to maintenance personnel.
I This occurrence is reportab'le in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.
NRC FGRM 366 <9-2007) (9-2007)
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME 1
- 2. DOCKET I
- 6. LER NUMBER I
- 3. PAGE I
I I
I I
SEQUENTIAL
~EVlSlON YEAR NUMBER NUMBER
EVENT DESCRIPTION
On December 27, 2007, during the performance of Technical Specification (TS) surveillance testing of the main station batteries [BTRY;EJ], the float voltage of battery cell 43 on the right trair station battery was found to be below the allowable TS limit for this parameter. The float voltage allowable limit for each connected cell is >2.07 V. The battery cell 43 float voltage was measured at 2.058 V.
However, at the time of this discovery, it was not recognized that the parameter was actually below the specified TS battery cell limit. Subsequently, on December 28, 2007, during review of the surveillance data and discussion with members of the electrical maintenance department who had performed the surveillance, an on-duty senior reactor operator recognized the low reading for battery cell 43. The appropriate TS actions were referenced for this condition, resulting in declaring the right train station battery inoperable.
The delay of over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in recognizing that battery cell 43 float voltage was below the TS limit for this parameter resulted in not meeting the TS completion time for required actions in accordance with TS 3.8.6.A and TS 3.8.6.B, that were applicable from the initial discovery time.
Ultimately, the required action to immediately declare the right train station battery inoperable was not met. Additionally, with the right train station battery inoperable, TS 3.8.4.8 requires a verification that both the directly connected and cross-connected battery chargers [BYC;EJ] are supplying power to the affected train with a completion time of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, and that the station batten be restored to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. With these required actions and associated completion times not met, the required actions of TS 3.8.4.C requiring Mode 3 entry in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Mode 5 entry in 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> were also not met.
This occurrence is reportable in accordance with 10 CFR 50.73(a)(Z)(i)(B) as a condition prohibited by Technical Specifications.
CAUSE OF THE EVENT
Battery cell 43 experienced a sudden random failure without indication of a prior adverse trend, The failure of the electrical maintenance crew to initially recognize that the battery cell 43 voltage was below the TS limit was attributed to an inadequate pre-job brief that did not review acceptance criteria details, or required actions if acceptance criteria were not met. Additionally, neither the supervisor nor involved engineer attended the pre-job brief, and they also failed to recognize that battery cell 43 voltage was below the TS limit.
IRG FORM 36FA !9-2007)
CORRECTIVE ACTIONS
Battery cell 43 was replaced. The failed battery cell 43 will be analyzed to confirm the failure mode.
Pre-job brief performance expectations will be re-iterated to maintenance personnel. Enhanced pre-job brief attendance expectations will be established.
SAFETY SIGNIFICANCE
The event is considered to be of very low safety significance. The overall battery capacity for the right train station battery was assessed and determined to have sufficient margin to meet design basis loading assumptions even if zero credit is taken for battery cell 43.
The plant remained at 100°/o power throughout the incident.
PREVIOUS SIMILAR EVENTS
None