I hope there was no combustion gases discover in the transformer coolant oil before these recent event...
Start-Up Transformer Degraded Voltage Relay Found Outside Technical Specification Limit
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1. FACILITY NAME 2. DOCKET NUMBER .PAGE Pilgrim Nuclear Power Station 05000-293 1 OF3
4. TITLE Start-Up Transformer Degraded Voltage Relay Found Outside Technical Specification Limit
5. EVENT DATE 6. LER NUMBER 7. REPORT DATE 8. OTHER FACILITIES INVOLVED
SEQUENTIAL
FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR REV MONTH DAY YEAR N/A NUMBER NO. 05000 N/A
09 13 2017 2017 - 012 - 00 11 13 2017
FACILITY NAME DOCKET NUMBER N/A 05000 N/A
9. OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: 'Check all that apply)
N
D 20.2201(b) D 20.2203(a)(3)(i) D 50.73(a)(2)(ii)(A) D 50.73(a)(2)(viii)(A) D 20.2201(d) D 20.2203(a)(3)(ii) D 50.73(a)(2)(ii)(B) D 50.73(a)(2)(viii)(B) D 20.2203(a)(1) D 20.2203(a)(4) D 50.73(a)(2)(iii) D 50.73(a)(2)(ix)(A) D 20.2203(a)(2)(i) D 50.36(c)(1)(i)(A) D 50.73(a)(2)(iv)(A) D 50.73(a)(2)(x) 10. POWER LEVEL D 20.2203(a)(2)(ii) D 50.36(c)(1)(ii)(A) D 50.73(a)(2)(v)(A) D 73.71(a)(4) D 20.2203(a)(2)(iii) D 50.36(c)(2) D 50.73(a)(2)(v)(B) D 73.71(a)(5) 100 D 20.2203(a)(2)(iv) D 50.46(a)(3)(ii) D 50.73(a)(2)(v)(C) D 73.77(a)(1) D 20.2203(a)(2)(v) D 50.73(a)(2)(i)(A) D 50.73(a)(2)(v)(D) D 73.77(a)(2)(i) D 20.2203(a)(2)(vi) ~ 50.73(a)(2)(i)(B) D 50.73(a)(2)(vii) D 73.77(a)(2)(ii) D 50.73(a)(2)(i)(C) 0 OTHER Specify in Abstract below or in NRG Form 366A 12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT ~ELEPHONE NUMBER (Include Area Code) IMr. Everett P. Perkins, Jr. - Regulatory Assurance Manager 508-830-8323 13. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT
CAUSE SYSTEM COMPONENT
MANU- REPORTABLE
CAUSE SYSTEM COMPONENT
MANU- REPORTABLE FACTURER TOEPIX FACTURER TOEPIX B EA 27 ABB y N/A N/A N/A N/A N/A
14. SUPPLEMENTAL REPORT EXPECTED 15. EXPECTED MONTH DAY YEAR ~ YES (ff yes, complete 15. EXPECTED SUBMISSION DATE) D NO SUBMISSION DATE 02 01 2018 ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On September 13, 2017 with the unit at 100 percent power, Pilgrim Nuclear Power Station discovered during calibration of four Start-Up Transformer Degraded Voltage Relays (ABB model number ITE27N) after the relays had been removed from the plant, relay 127 A-604/1 had an as-found setpoint value outside the Technical Specifications Table 3.2.B limit of 110.6 plus or minus 0.56 Volts ac (Vac) (110.04 - 111.16); the as-found value was 109.90 Vac. This relay was replaced with a spare relay that was calibrated prior to its installation.
Pilgrim Nuclear Power Station is submitting this Licensee Event Report in accordance with 10 CFR 50.73(a)(2)(i)(B)-Any operation or condition that was prohibited by the plant's Technical Specifications.
This event was not risk significant. There was no threat to public health and safety from this condition.
NRC FORM 366 (04-2017)
NRC FORM 366A (04-2017)
u_s. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 3/31/2020
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
(See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3D
Estimated burden per response to comply with this mandatory collection request: 80 hours. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the Information Services Branch (T-2 F43), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to lnfocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid 0MB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
1. FACILITY NAME 2. DOCKET NUMBER 3. LER NUMBER
YEAR
Pilgrim Nuclear Power Station 05000-293
2017
NARRATIVE
BACKGROUND
SEQUENTIAL NUMBER
- 012
REV NO.
-00
The startup transformer supplies power to the station auxiliary power distribution system whenever the main generator is offline_ After the main generator has been synchronized to the 345 kV system and has been partially loaded, the auxiliary power distribution system is manually transferred from the start-up transformer (SUT) to the unit AC power source (unit auxiliary transformer [UAT]).
Automatic fast transfer capability is provided in the design to restore the auxiliary power distribution system to its preferred offsite AC power source, the SUT, in the event that the unit AC power source (UAT) is lost for any reason_ The diesel generator load shedding logic will also be actuated immediately upon the fast transfer of the safety related buses A5 and A6 to the SUT if a Loss-Of-Coolant-Accident signal is present when the SUT secondary voltage is below the degraded voltage alarm reset setpoint.
The primary function of the 127 A-604/1 degraded voltage relays and their settings for the SUT is to ensure a minimum voltage at which the emergency buses can be operated indefinitely to provide their intended safety functions. If voltage drops below that point for a specified time limit, the degraded voltage relays will initiate transfer of the emergency buses from offsite power to the onsite emergency diesel generators.
EVENT DESCRIPTION
During calibration of four SUT Degraded Voltage Relays (ABB model number ITE-27N) after the relays had been removed from the plant, relay 127 A-604/1 had an as-found setpoint value outside the Technical Specifications (TS) Table 3.2.B limit of 110.6 plus or minus 0.56 Volts ac (Vac) (110.04 - 111.16). The asfound value was 109.90 Vac. This relay was replaced with a spare relay that was calibrated prior to its installation.
CAUSE OF THE EVENT
rThe cause of the relay's potential inoperability is still under investigation at this time.
CORRECTIVE ACTIONS
The relay was replaced, restoring the safety function of the SUT degraded voltage relay to initiate transfer of the emergency buses from offsite power to the onsite emergency diesel generators.
NRG FORM 366A (04-2017) Page 2 of 3
NRC FORM 366A (04-2017)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 3/31/2020
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
(See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.gov/reading-rm/doc-collections/nureqs/staff/sr1022/r3/)
Estimated burden per response to comply with this mandatory collection request: 80 hours. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the Information Services Branch (T-2 F43), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to lnfocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid 0MB control number, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
1. FACILITY NAME 2. DOCKET NUMBER 3. LER NUMBER
YEAR
Pilgrim Nuclear Power Station 05000-293
2017
NARRATIVE
SAFETY CONSEQUENCES
SEQUENTIAL NUMBER
- 012
REV NO.
- 00
The 127 A-604/1 Degraded Voltage Relay As-Found setpoint value was outside the TS limits. However, per calculation PS147 "Degraded Voltage Trip Relays, Revised Voltage Setpoint" the as-found value was within the analytical limits, which indicates that the degraded voltage relay would operate within safety limits albeit outside the TS limits.
Calculation PS147 "Degraded Voltage Trip Relays, Revised Voltage Setpoint" establishes the trip setpoint, analytical limits, and the no adjust limits for the voltage function of the degraded voltage trip relays (127A-504/1,2,3,4 and 127A-604/1,2,3,4). The upper and lower analytical limits are the limit of a measured or calculated variable established by the plant safety analysis to ensure that a safety limit is not exceeded. The as-found value found for this relay was 109.9 Vac which was outside the TS limits. However, per PS147, the lower analytical limit is 109.75 Vac. Therefore, the as-found value for 127A604/1 does not exceed the established safety limit, and the relay is capable of performing its safety function.
There were no public safety, nuclear safety, industrial safety or radiological safety consequences from this event. No actions to reduce the frequency or consequence are necessary.
REPORT ABILITY
Pilgrim Nuclear Power Station is submitting this Licensee Event Report (LER) in accordance with 10 CFR 50.73(a)(2)(i)(B)-Any operation or condition that was prohibited by the plant's Technical Specifications.
PREVIOUS EVENTS
~ review of PNPS LERs for the past five years did not identify any other LERs that were submitted for the same reason as this submittal.
REFERENCES
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