05000400/LER-2009-001, Regarding Emergency Bus 1A-SA Undervoltage Relay as Found Dropout Voltage Did Not Meet TS Allowable Values
| ML091470280 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 05/18/2009 |
| From: | Henderson K Progress Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| HNP-09-058 LER 09-001-00 | |
| Download: ML091470280 (4) | |
| 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 |
| 4002009001R00 - NRC Website | |
text
P~rogress EnergySea, ro res rgSerial:
HNP-09-058 MAY 1`8 '2009 10 CFR 50.73 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 DOCKET NO. 50-400/LICENSE NO. NPF-63 LICENSEE EVENT REPORT 2009-001-00 Ladies and Gentlemen:
The enclosed Licensee Event Report (LER) 2009-001-00 is submitted in accordance with 10 CFR 50.73, paragraph (a)(2)(i)(B) as a condition prohibited by the plant Technical Specifications. This report describes the discovery of an incorrect calibration of dropout voltage for two undervoltage relays. In accordance with 10 CFR 50.73(a) requirements, this LER is submitted within 60 days following discovery of the event.
This document contains no Regulatory Commitments.
Please refer any questions regarding this submittal to Mr. Dave Corlett, Supervisor -
Licensing/Regulatory Programs, at (919) 362-3137.
Sincerely, Kelvin Henderson Plant General Manager Harris Nuclear Plant KH/kms Enclosure cc:
Mr. J. D. Austin, NRC Senior Resident Inspector, HNP Mr. L. A. Reyes, NRC Regional Administrator, Region II Ms. M. G. Vaaler, NRC Project Manager, HNP Progress Energy Carolinas, Inc.
Harris Nuclear Plant P. 0. Box 165 New Hill, NC 27562
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010 (9-2007)
, the NRC may not conduct digits/characters for each block) or sponsor, and a person is not required to respond to, the information collection.
- 13. PAGE Harris Nuclear Plant - Unit 1 05000400 1 OF 3
- 4. TITLE Emergency Bus 1A-SA Undervoltage Relay As Found Dropout Voltage did not meet TS Allowable Values
- 5. EVENT DATE
- 6. LER NUMBER _
- 7. REPORT DATE
[
- 8. OTHER FACILITIES INVOLVED SEQAENTIAL REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQNUMTBER NO.
MONTH DAY YEAR IN/A 05000 IFACILITY NAME DOCKET NUMBER 03 18 2009 2009 001 001 05 18 2009 1N/A 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)
El 20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii)
El 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
[E 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
E-50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 1] 20.2203(a)(2)(ii)
[I 50.36(c)(1)(ii)(A) 0l 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El.20.2203(a)(2)(iii)
[] 50.36(c)(2)
[E 50.73(a)(2)(v)(A)
El 73.71(a)(4)
[E 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5) 100 E] 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi)
ER 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in Potential Safety Consequences:
The only potential safety consequences are related to how the setpoint calibration error on the primary undervoltage relays could affect the timing of the diesel start signal on a loss of voltage. Based on the operating curves for NGV relays, a -1.5 V calibration error willresult in a -1 ms delay. The delay time is based on a drop from 110% of nominal voltage (120 V) to 50% of the dropout voltage setting (-40 V).
A-Harris Engineering Calculation allows a maximum setting of 1.12 seconds with a TS Table 3.3-4 Allowable Value of < 1.5 seconds. The last performance of MST-E0075 was reviewed for both safety busses and the additional 1 ms delay would not have resulted in a TS violation or out of range time setting. The additional delay due to the calibration error did not have any significant effect on the protective features of the primary undervoltage relays.
IV. CORRECTIVE ACTIONS
The affected 1A-SA relays were recalibrated per MST-E0075 and the test was satisfactorily completed on January 26, 2009. Additionally, the same model 1B-SB relays were also checked. Since the extent of condition was Model 12NGV13 relays with Allowable Values defined in TS, additional UV relays will also be tested at a nominal 120 V starting point.
Process verification steps are being added to procedures performed with Pulsar software, Pulsemaster and Advanced Visual Test Software (AVTS), which will provide a listing with critical test parameters and description of the test being performed automatically by the Pulsar software. Setpoint changes for emergency bus primary. UV relays are being implemented to increase the margin between setpoint and Allowable Value.
V. PREVIOUS SIMILAR EVENTS, A review of LER and Action Requests over the past five years identified one similar Action Request (AR):
AR 231046231046 originated April 26, 2007 - Undervoltage Relays for the lA-SA Bus were found out of calibration while performing MST-E0075 on undervoltage relays 27-3/1729. The remaining 2 of 3 logic for the 1A safety bus undervoltage protection remained operational. The apparent causes were determined to be design differences between relay types and effects on calibration methodologies, not identified until after the relays had been accepted and installed, and the failure of calibration procedures to forewarn users of the possibility of unintentionally affecting other contact pair setpoints when adjusting a target contact pair setpoint. The potential link between the relay coil voltage level and dropout setting was not a factor in this 2007 report.PRINTED ON RECYCLED PAPERPRINTED ON RECYCLED PAPER