05000293/LER-2018-003, Target Rock Relief Valve Pilot Assembly Failed As-Found Lift Test, a Condition Prohibited by Plant Technical Specifications
| ML18093A388 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 04/27/2018 |
| From: | Miner P Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 2018-003-00 | |
| Download: ML18093A388 (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)(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)(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) |
| 2932018003R00 - NRC Website | |
text
March 27, 2018 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 2018-003-00, Target Rock Relief Valve Pilot Assembly Failed As-Found Lift Test, a Condition Prohibited by Plant Technical Specifications Pilgrim Nuclear Power Station Docket No. 50-293 Renewed License No. DPR-35 LETTER NUMBER:
2.18.015
Dear Sir or Madam:
The enclosed Licensee Event Report 2018-003-00, Target Rock Relief Valve Pilot Assembly Failed As-Found Lift Test, a Condition Prohibited by Plant Technical Specifications, is submitted in accordance with Title 1 O Code of Federal Regulations 50.73.
If you have any questions or require additional information, please contact me at (508) 830-7127.
There are no regulatory commitments contained in this letter.
Sincerely, Peter J.
i er
- Manager, egulatory Assurance PJM/sc
Attachment:
Licensee Event Report 2018-003-00, Target Rock Relief Valve Pilot Assembly Failed As-Found Lift Test, a Condition Prohibited by Plant Technical Specifications (3 Pages)
Entergy Nuclear Operations, Inc.
Pilgrim Nuclear Power Station cc:
Mr. David C. Lew Acting 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 NRC Senior Resident Inspector Pilgrim Nuclear Power Station Letter No. 2.18.015 Page 2 of 2
Attachment Letter Number 2.18.015 Licensee Event Report 2018-003-00, Target Rock Relief Valve Pilot Assembly Failed As-Found Lift Test, a Condition Prohibited by Plant Technical Specifications (3 Pages)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2017) httg://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r30 the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
.PAGE Pilgrim Nuclear Power Station 05000293 1 OF3
- 4. TITLE Target Rock Relief Valve Pilot Assembly Failed As-Found Lift Test, a Condition Prohibited by Plant Technical Specifications
- 5. EVENT DATE
- 6. LEA NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL REV FACILITY NAME DOCKFT NUMBER MONTH DAY YEAR YEAR NUMBER NO.
MONTH DAY YEAR N/A 05000 N/A 01 26 2018 2018
- - 003
- - 00 03 27 2018 FACILITY NAME N/A DOCKET NUMBER 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 so.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 so.36(c)(2)
D 50.73(a)(2)(v)(B)
D 73.71 (a)(5) 100 D 20.2203(a)(2)(iv)
D so.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 LEA LICENSEE CONTACT rr 1
ELEPHONE NUMBER (Include Area Code)
Mr. Peter J. Miner-Regulatory Assurance Manager (508) 830-7127 CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TOEPIX FACTURER TOEPIX B
SB RV T020 y
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR D YES (If yes, complete 15. EXPECTED SUBMISSION DATE}
[8J NO SUBMISSION DATE
~BSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On January 26, 2018, while operating at 100 percent core thermal power, Pilgrim Nuclear Power Station was notified that one of the four Target Rock Relief Valve Pilot Assemblies removed from the plant during the 2017 Refueling Outage exceeded the Technical Specification (TS) tolerance limit of 1155 +/- 34.6 psig (+/- 3%) during routine testing at the offsite vendor's test facility. Certified replacement relief valve pilot assemblies were installed in the plant during the Spring 2017 Refueling Outage.
IThe cause of the as-found initial lift pressure exceeding the TS tolerance limit for the pilot valve was corrosion bonding.
This report is submitted in accordance with the requirements of Title 1 O Code of Federal Regulations 50.73{a)(2)(i)(B), any operation or condition which was prohibited by plant Technical Specifications.
There were no adverse consequences for this event and the condition posed no threat to public health and safety because an evaluation of the as-found set pressures of the four relief valves concluded that no design or licensing basis limits would have been exceeded had the relief valve pilot assemblies been required to operate.
BACKGROUND 05000-293 YEAR 2018 SEQUENTIAL NUMBER
- - 003 REV NO.
- - 00 The Pilgrim Nuclear Power Station (PNPS) Pressure Relief System (PRS) is designed to prevent over-pressurization of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code qualified nuclear steam supply system. The PRS consists of two safety valves and four two-stage relief valves. These valves are installed in the main steam system piping upstream of the main steam isolation valves and are located within the drywall. The safety valves are self-actuating, provide over-pressure protection, and discharge directly to the drywall atmosphere when actuated. The relief valves augment the safety valves and are sized to prevent unnecessary actuation of the safety valves. The relief valves are self-actuating and discharge into the suppression pool through discharge piping connected to the valves. Each two-stage relief valve consists of a pilot assembly and a main stage. The pilot assembly provides the pressure sensing function and the main stage provides the pressure relieving function. The relief valves are also part of the Automatic Depressurization System (ADS). As part of the ADS, the relief valves are designed to automatically actuate as a result of a reactor depressurization permissive signal, and can also be manually actuated from the Control Room or Alternate Shutdown Panel for depressurization.
Technical Specification (TS) 4.6.D.1 specifies the lift setpoint of the relief valves shall be 1155 +/- 34.6 psig. The nameplate setpoint of each relief valve is 1155 psig.
The Main Steam Relief Valves were manufactured by Target Rock Corporation.
In the 2017 Refueling Outage PNPS installed Target Rock Relief Valve Pilot Assemblies with discs that were platinum coated via the ion beam assisted deposition (IBAD) process.
EVENT DESCRIPTION
On January 26, 2018, PNPS was notified that one (Serial Number [SN] 1025) of the four Target Rock relief tvalve pilot assemblies exceeded the TS tolerance limit of 1155 +/- 34.6 psig (+/- 3%) during routine testing at the offsite vendor's test facility. Certified replacement relief valve pilot assemblies were installed in the plant during
~he Spring 2017 Refueling Outage.
!There were no adverse consequences from this event and the condition posed no threat to public health and safety because an evaluation of the as-found set pressures of the four relief valves concluded that no design or licensing basis limits would have been exceeded had the relief valve pilot assemblies been required to operate.
CAUSE OF THE EVENT
The cause of the as-found initial lift pressure exceeding the TS tolerance limit for the pilot valve was determined
- o be corrosion bonding. The relief valve (SN* 1025) set point was below 1189.6 psig during subsequent lifts, which is within the allowable range. The performance exhibited by SN 1025 is consistent with corrosion bonding between the Stellite 21 disc and Stellite 6 seat. The corrosion bonding is a time dependent process hat develops to varying levels of severity. Page 2 of 3 (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
, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. LEA NUMBER Pilgrim Nuclear Power Station 05000-293
CORRECTIVE ACTIONS
YEAR 2018 SEQUENTIAL NUMBER
- - 003 The installed pilot valve assemblies have Stellite 68 discs with a platinum coating applied using the IBAD process. The objective of the change to the Stellite 68 platinum coated discs was to minimize corrosion bonding.
SAFETY CONSEQUENCES
REV NO.
- - 00 The SN 1025 as-found set point of 1197 psig exceeds the TS 4.6.D.2 limit of 1189.6 psig by 7.4 psig.
Overpressure protection depends on the operation of the entire compliment of four relief valve pilot assemblies.
rThe entire compliment of Target Rock Relief Valve pilot assemblies were tested. The average of the test results of all four relief valve pilot assemblies resulted in an average lift pressure of 1181.5 psig which is below
~he upper analytical setpoint limit of 1189.6 psig. Therefore, PNPS analysis concluded the cycle specific overpressure protection results were not adversely affected, and the plant was not placed in an unanalyzed condition.
There were no consequences to the general safety of the public, nuclear safety, industrial safety or radiological safety from this event.
REPORTABI LITY:
This report is submitted in accordance with the requirements of 1 O CFR 50.73 (a)(2)(i)(B), any operation or condition which was prohibited by plant Technical Specifications.
PREVIOUS EVENTS:
A review of the PNPS database for the past five years did not identify any LERs that were submitted for similar occurrences.
REFERENCES:
CR-PNP-2018-00820 Page 3 of 3