05000293/LER-1917-009, Regarding Potential Primary Containment System Lnoperability Due to Relay Concerns
| ML17220A063 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 07/17/2017 |
| From: | Perkins E Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 2.17.050 LER 17-009-00 | |
| Download: ML17220A063 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat |
| 2931917009R00 - NRC Website | |
text
~Entergx July 17, 2017 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001 Entergy Nuclear Operations, Inc.
Pilgrim Nuclear Power Station 600 Rocky Hill Road Plymouth, MA 02360
SUBJECT:
Licensee Event Report 2017-009-00, Potential Primary Containment System lnoperability Due to Relay Concerns Pilgrim Nuclear Power Station Docket No. 50-293 Renewed License No. DPR-35 LETTER NUMBER:
2.17.050
Dear Sir or Madam:
The enclosed Licensee Event Report 2017-009-00, Potential Primary Containment System lnoperability Due to Relay Concerns, is submitted in accordance with Title 10 Code of Federal Regulations 50. 73.
If you have any questions or require additional information, please contact me at (508) 830-8323.
There are no regulatory commitments contained in this letter.
Sincerely,
~\\)~
Everett P. Perkins, Jr.<
~
Manager, Regulatory Assurance EPP/sc
Attachment:
Licensee Event Report 2017-009-00, Potential Primary Containment System lnoperability Due to Relay Concerns (3 Pages)
Entergy Nuclear Operations, Inc.
Pilgrim Nuclear Power Station cc:
Mr. Daniel H. Dorman Regional Administrator, Region I U.S. Nuclear Regulatory Commission 2100 Renaissance Blvd., Suite 100 King of Prussia, PA 19406-2713 Mr. John Lamb, Senior Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 0-8C2A Washington, DC 20555 USNRC Senior Resident Inspector Pilgrim Nuclear Power Station Letter No. 2.17.050 Page 2 of 2
Attachment Letter Number 2.17.050 Licensee Event Report 2017-009-00 Potential Primary Containment System lnoperability Due to Relay Concerns (3 Pages)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2017) h!!Q://www.nrc.gov/reading-nn/doc-collections/nur~s/staff/sr1022/r3/)
the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 1. FACILITY NAME
- 12. DOCKET NUMBER
- 13. PAGE Pilgrim Nuclear Power Station 05000293 1 OF3
- 14. TITLE Potential Primary Containment System lnoperability Due to Relay Concerns
- 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 05 17 2017 2017
- - 009 00 07 17 2017 FACILITY NAME DOCKET NUMBER N/A 05000 N/A
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMEN'TS OF 10 CFR 6: Check all that appl_v)
N D 20.2201(b)
D 20.22oa(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 20.22oa(a)(1)
D 20.22oa(a)(4)
D 50.73(a)(2)(iii)
D 50.73(a)(2)(ix)(A)
D 20.22oa(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 20.22oa(a)(2)(ii)
D 50.36(c)(1 )(ii)(A)
D 50.73(a)(2)(v)(A)
D 73.71(a)(4)
D 20.22oa(a)(2J(iii)
D 50.36(c)(2)
[8'J 50. 73(a)(2)(v)(B)
D 73.71(a)(5) 0 D 20.2203(a)(2)(iv)
D 50.46(a)(3)(ii)
[8'J 50.73(a)(2)(v)(C) tJ 73.77(a)(1)
D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
[8'J 50.73(a)(2)(v)(D)
D 73.77(a)(2)(i)
D 20.2203(a)(2)(vi)
[8'J 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 NRC Form 366A
- 12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT llLEPHONE NUMBER (Include Area Code)
IMr. Everett P. Perkins, Jr. - Regulatory Assurance Manager 1508-830-8323 CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TOEPIX FACTURER TOEPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR (gl YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
D NO SUBMISSION DATE 10 11 2017
!ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On May 17, 2017, during Refueling Outage (RF0)-21 while performing an extent of condition review for condition reports it was discovered that the contact indicating tabs of relays 16A-K30 and 16A-K54 of the Pilgrim Nuclear Power Station (PNPS) Primary Containment System, were visually not completely in the mid-position (partial travel).
IThe relays were replaced during RF0-21 and sent to an offsite vendor for further testing and analysis. Other relays iwere reviewed to determine if a similar condition may exist; however, the other relays reviewed are not the same type (DC relays and normally energized) and are therefore outside the scope of this extent of condition review.
Pilgrim Nuclear Power Station is conservatively submitting this Licensee Event Report in accordance with 10 CFR 50.73(a)(2)(i)(B)- Operation or condition prohibited by Technical Specifications; and potentially in accordance with 10 CFR 50. 73(a)(2){v)(B), (C) and (D) - Any condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to remove residual heat, control the release of radioactive material and mitigate the consequences of an accident.
rrhis event posed no threat to public health and safety.
NRC FORM 366 (04-2017) (04-2017)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: 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 htto://www.nrc.gov/readinq-rm/doc-collections/nureas/staff/sr1022/r3/)
, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. LER NUMBER Pilgrim Nuclear Power Station 05000-293 YEAR 2017 BACKGROUND SEQUENTIAL NUMBER
- - 009 REV NO.
- - 00 rThe safety objective of the Primary Containment System (PCS) is to provide the capability in conjunction with other safeguards features to:
Limit the release of fission products in the event of a postulated design basis accident so that offsite doses would not exceed the guideline values set forth in 10 CFR 100.
To prevent excessive fuel cladding temperatures.
lrhe Shutdown Cooling (SOC) subsystem is an integral part of the Residual Heat Removal (RHR) system and is placed in operation during normal shutdown and cooldown. The initial phase of nuclear system cooldown is accomplished by dumping steam from the reactor vessel to the main condenser rwith the main condenser acting as a heat sink. When the nuclear system pressure has decreased to 50 psig the steam supply pressure is no longer sufficient to maintain vacuum in the condenser, the RHR system is placed in the SOC mode of operation to complete cooldown of the nuclear system.
Inboard and outboard shutdown suction cooling line isolation valves have an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> mission time.
Group 3 Isolation isolates the SOC mode of the RHR system from the reactor vessel, when conditions indicate a system breach or over pressurization. Relay 16A-K54 gets an initiation signal on high reactor pressure and provides a signal to relay 16A-K30 to energize to close M0-1001-47 (RHR SOC outboard isolation valve). This 16A-K30 relay also isolates the RHR shutdown cooling valve on any one of the following conditions:
a. Reactor low water level (+12 inches) b. High drywall pressure (+2.2 psig) c.
High reactor pressure (76 psig)
The high reactor pressure isolation setpoint prevents over pressurizing the RHR low pressure piping.
EVENT DESCRIPTION
On May 17, 2017, during Refueling Outage 21 while performing an extent of condition review for condition reports it was discovered that the contact indicating tabs of relays 16A-K30 and 16A-K54 of the Pilgrim Nuclear Power Station (PNPS) Primary Containment System, were visually not completely in the mid-position (partial travel).
CAUSE OF THE EVENT
The cause of the relays potential inoperability is indeterminate at this time. This relays have been sent to an offsite vendor for further testing and analysis.
CORRECTIVE ACTIONS
The relays were replaced, restoring the capability of the Group 3 Isolation of the SOC mode of RHR. Page 2 of 3 (04-2017)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 3/31/2020
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LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form htto://www.nrc.gov/readinq-rm/doc-collections/nuregs/staff/sr1022/r3/)
, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. LER NUMBER YEAR Pilgrim Nuclear Power Station 05000-293 2017 SEQUENTIAL NUMBER
- - 009 REV NO.
- - 00 Forensic testing is being performed on the removed relays. Any additional corrective actions will be entered into the PNPS Corrective Action Program.
SAFETY CONSEQUENCES
These relays are normally energized and must de-energize to provide Primary Containment Isolation System (PCIS) isolation signal. With the relay contact indicating tabs in a mid-position, there is a potential the contacts would not have completely opened during an accident condition and provided the necessary trip signals for the PCIS logic. The 16A-K53 relay affects the Inboard PCIS logic with the Outboard PCIS logic affected by 16A-K54. With both relays in the same unanalyzed condition system redundancy cannot be credited.
During plant operations the risk of operation with potentially degraded relays in the SOC isolation system is minimal as both trains of Shutdown Cooling Isolation Valves are in the closed position with power removed. With their power removed it is not possible for the Shutdown Cooling Isolation Valves to realign to an undesirable position due to a relay malfunction.
This condition was discovered during the refueling outage when conditions were such that the equipment normally energized/activated by these relays were not required to be operable and there is no firm evidence that the condition existed during plant operation.
There are no consequences to the general safety of the public, nuclear safety, industrial safety and radiological safety from this event. No actions to reduce the frequency or consequence are necessary.
REPORT ABILITY PNPS is submitting this LER in accordance with 10 CFR 50.73(a)(2)(i)(B)- Operation or condition prohibited by Technical Specifications; and potentially in accordance with10 CFR 50.73(a)(2)(v)(B), (C) and (D)-Any condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to remove residual heat, control the release of radioactive material and mitigate the consequences of an accident.
PREVIOUS EVENTS A 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:
CR PNP-2017-5390 CR PNP-2017-5396 Page 3 of 3