05000373/LER-2018-003, Regarding Two Main Steam Safety Relief Valves Failed Inservice Lift Inspection Pressure Test

Regarding Two Main Steam Safety Relief Valves Failed Inservice Lift Inspection Pressure Test

ML18117A216
Person / Time
Site:	LaSalle
Issue date:	04/27/2018
From:	Vinyard H Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RA18-027 LER 2018-003-00
Download: ML18117A216 (4)

LER-2018-003, Regarding Two Main Steam Safety Relief Valves Failed Inservice Lift Inspection Pressure Test

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(viii)(A) 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) 10 CFR 50.73(a)(2)(v), Loss of Safety Function
3732018003R00 - NRC Website

text

Exelon Generation,

RA18-027 April 27, 2018 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LaSalle County Station, Unit 1 Renewed Facility Operating Licenses No. NPF-11 NRC Docket No. 50-373 LaSalle County Station 2601 North 21 *1 Road Marseilles, IL 61341 815-415-2000 Telephone www.exeloncorp com 10 CFR 50.73

Subject:

Licensee Event Report 2018-003-00, Two Main Steam Safety Relief Valves Failed lnservice Lift Inspection Pressure Test In accordance with 1 O CFR 50.73(a)(2)(i)(B), Exelon Generation Company, LLC (EGC) is submitting Licensee Event Report (LEA) Number 2018-003-00 for LaSalle County Station, Unit 1.

There are no regulatory commitments in this letter. Should you have any questions concerning this report, please contact Mr. Guy V. Ford, Jr., Regulatory Assurance Manager, at (815) 415-2800.

ii::i"IV~

Harold T. Vinyard Plant Manager LaSalle County Station

Enclosure:

Licensee Event Report cc:

Regional Administrator - NRC Region Ill NRC Senior Resident Inspector - LaSalle County Station

NRC FORM366 (02-2018)

U.S. NUCLEAR REGULA TORY COMMISSION LICENSEE EVENT REPORT (LER)

(See Page 2 for required number of digits/characters for each block)

(See NUREG-1022, R.3 for instruction and guidance for completing this fom1 http://www nrc.gov/readinq-rm/doc*collections/nuregsistaff/sr1022/r3il APPROVED BY OMB: NO. 3150-0104 EXPIRES: 0313112020 E*tinated luden per rasponoe lo comp~ with this mandatory colloclion request 80 ho<n.

Reported lessens letrnad,,. in<orpora19d lnlo 1he licensing P'OC8SS and fod bact< lo lndusrt Send comments regwdlng burtlen aatimale lo lhe lnlormati:Jn Services Branch (T-2 F43), U.S. N<.<:lear RogulalDry Commlsoloo, Washlnglon, QC 20555-0001, a by a-maN lo lnfocollocts.R......,.@~gov, and lo 1he o..i. Oflieer, Ofli:e of lnlamotion end Regulaby Alfan, NEOB-10202. (3150<l104), Office of Management and Budge\\

Washinglcn, OC 20503.

If a means uoad lo Impose an Information coleclion does not

<ioplay a curan11y vaHd OMB contaf oonaer. h> NRC may not CO<OJct or sponsor. and a person Is not requilad lo ""'pond lo, the illormalion coletti>n.

3. Page 1

LaSalle County Station, Unit 1 05000373 OF 3

4. Title Two Main Steam Safety Relief Valves Failed lnservice Lift Inspection Pressure Test

5. Event Date

6. LER Number

7. Report Date

8. Other Facilities Involved I

Sequential I Rev Faclllty Name Docket Number Year Number No.

Month Day Year NA NA Month Day Year Faclflty Name Docket Number 02 27 18 2018 -

003 00 04 27 18 NA NA

9. Operating Mode

11. This Report Is Submitted Pursuant to the Requirements of 1 O CFR §: (Check all that apply)

D 20.2201 (bl 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)(iil 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) 1 D 20.2203(a><2>

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)(iil D 50.36(c)(1 )(ii}(A}

D 50. 73(a)(2}(v)(A)

D 73.71(a)(4)

D 20.2203(a)(2)(ii1>

D 50.36(c)(2}

D 50. 73(a)(2)(v)(B}

D 73. 71 (a)(5)

D 20.2203(a)(2)(iv)

D 50.46(a)(3)(ii)

D 50. 73(a)(2)(v}(C)

D 13.77(a)(1>

000 D 20.2203(a}(2)(v}

D 50.73(a}(2)(1)(A}

D 50.73(a)(2)(v)(D}

D 13.77(a)(2)(iil D 20.2203(a}(2)(vi)

~ 50. 73(a)(2)(i)(B)

D 50. 73(a}(2)(vii}

D 13.77<a><2><m>

D 50.73(a)(2)(i}(C)

D Other (Specify in Abstract below or in NRC Fom1 366A)

12. Licensee Contact for this LER Licensee Contact John Keenan, Engineering Director Telephone Number (Include Area Code)

(815) 415-3800 I Component I Manufacturar I Reportable to ICES RV C710 Yes

Cause

System Component Manufacturer I Reportable to ICES NA NA NA NA NA I

Cause

System x

AD

14. Supplemental Report Expected Month Day Year

15. Expected Submission Date 07 27 2018

~

Yes (If yes. complete 15. Expected Submission Date) D No Abstract (Limit to 1400 spaces, i.e., approximately 14 single-spaced typewritten lines)

During the February 2018 Unit 1 refueling outage, two main steam safety relief valves (SRV) did not pass Technical Specification (TS) Surveillance Requirement 3.4.4.1 and lnservice Testing (IST) Program lift pressure requirements. Both SRVs lifted below their expected lift pressures. On February 27, 2018, SRV 1 B21-F013R was required to lift within plus or minus three percent of 1205 psi (i.e., 1205 psi plus or minus 36.1 psi), but lifted at 1167 psi. On February 27, 2018, SRV 1 B21-F013U was required to lift within plus or minus three percent of 1150 psi (i.e., 1150 psi plus or minus 34.5 psi), but lifted at 1109 psi.

Multiple test failures are reportable under 10 CFR 50.73(a)(2)(i)(B) as an operation or condition prohibited by the plant's TS. Both SRVs lifted prior to their expected lift pressures, which is conservative regarding maintaining reactor pressure vessel over-pressure limits. Both SRVs were replaced during the outage. The cause of the event is under review by the vendor testing facility, and it will be reported in a supplement to this LER upon completion.

NRC FORM 366 (02-2018)

PLANT AND SYSTEM IDENTIFICATION

LaSalle County Station (LSCS) Unit 1 is a General Electric Boiling Water Reactor with 3546 Megawatts Thermal Rated Core Power.

The main steam safety relief valves (SRVs) are designed to prevent over-pressurization of the reactor pressure vessel (RPV) during transients and abnormal conditions, which protects against a failure of the reactor coolant pressure boundary (RCPB).

There are thirteen SRVs installed on the four main steam lines, which discharge near the bottom of the suppression pool to condense the steam through SRV tailpipes that exhaust beneath the suppression pool surface.

CONDITION PRIOR TO EVENT

Unit(s): 1 Reactor Mode(s): 5

DESCRIPTION

Date:

February 27, 2018 Mode(s) Name:

Refueling Time:

Power Level:

1520 CST 0 percent 00 During the February 2018 Unit 1 refueling outage, two main steam safety relief valves (SRV) did not pass Technical Specification (TS) Surveillance Requirement (SR) 3.4.4.1 and lnservice Testing (IST) Program lift pressure requirements. Both SRVs lifted below their expected lift pressures. On February 27, 2018, SRV 1 B21-F013R was required to lift within plus or minus three percent of 1205 psi (i.e.. 1205 psi plus or minus 36.1 psi), but lifted at 1167 psi. On February 27, 2018, SRV 1B21-F013U was required to lift within plus or minus three percent of 1150 psi (i.e., 1150 psi plus or minus 34.5 psi), but lifted at 1109 psi.

CAUSE

The cause of the event is under review by the vendor testing facility, and it will be reported in a supplement to this LER upon completion.

Station operating experience has shown a tendency for a portion of LSCS SRVs to experience minor setpoint drift sufficient to exceed the acceptance criteria of minus three percent over time. A license amendment request (LAR) was submitted to the NRC on February 27, 2018 to revise TS SR 3.4.4.1 to lower the setpoint tolerances for Unit 1 and Unit 2 SRVs. This proposed change would revise the SRV as-found lower tolerances from minus three percent to minus five percent to account for minor SRV setpoint drift in the conservative direction. This proposed change will reduce the unnecessarily restrictive surveillance requirement and will not impact the reliability of the SRVs or adversely impact their ability to perform their safety function. The change will reduce the number of TS SRV surveillance test failures for early lift pressure and preclude the submittal of previously reportable licensee event reports to the NRC due to setpoint drift in the low (conservative) direction.

REPORT ABILITY AND SAFETY ANALYSIS Multiple test failures are reportable under 10 CFR 50.73(a)(2)(i)(B) as an operation or condition prohibited by the plant's TS. Both SRVs lifted prior to their expected lift pressures, which is conservative regarding maintaining reactor pressure vessel over-pressure limits.

The safety significance of this condition was minimal. The out-of-tolerance lift pressures were discovered while Unit 1 was in Mode 5 during a refueling outage and the SRVs were not required to be operable. Both SRVs lifted prior to their expected lift pressures, which is conservative regarding maintaining reactor pressure vessel overpressure limits.

CORRECTIVE ACTIONS

Both SRVs 1 B21-F013R and 1B21-F013U were replaced during the outage. The cause of the event is under review by the vendor testing laboratory.

PREVIOUS OCCURRENCES

LER Unit 2 37 4-2015-002-01:

YEAR 2018 SEQUENTIAL NUMBER 003 REV NO.

00 During the February 2015 Unit 2 refueling outage L2R15, two main steam safety relief valves (SRV) did not pass TS Surveillance Requirement 3.4.4.1 and lnservice Testing Program lift pressure requirements. Both SRVs lifted below their expected lift pressures and were replaced during the outage. A failure analysis was conducted by a vendor testing laboratory, but the cause for the valves lifting below their set-point was indeterminate.

LER Unit 2 374-2017-004-01:

During the February 2017 Unit 2 refueling outage, two main steam safety relief valves (SRV) did not pass TS Surveillance Requirement 3.4.4.1 and lnservice Testing Program lift pressure requirements. Both SRVs lifted below their expected lift pressures and were replaced during the outage. A failure analysis was conducted by a vendor testing laboratory, but the cause for the valves lifting below their set-point was indeterminate.

COMPONENT FAILIRE DATA Manufacturer: Crosby Device: Main Steam Safety Relief Valves, ASME Section Ill, Class 1 Component ID: Style HB-65-BP, Size 6R10 NRC FORM 356A (04-2017)

Page _3_ of _3_

Exelon Generation,

RA18-027 April 27, 2018 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LaSalle County Station, Unit 1 Renewed Facility Operating Licenses No. NPF-11 NRC Docket No. 50-373 LaSalle County Station 2601 North 21 *1 Road Marseilles, IL 61341 815-415-2000 Telephone www.exeloncorp com 10 CFR 50.73

Subject:

Licensee Event Report 2018-003-00, Two Main Steam Safety Relief Valves Failed lnservice Lift Inspection Pressure Test In accordance with 1 O CFR 50.73(a)(2)(i)(B), Exelon Generation Company, LLC (EGC) is submitting Licensee Event Report (LEA) Number 2018-003-00 for LaSalle County Station, Unit 1.

There are no regulatory commitments in this letter. Should you have any questions concerning this report, please contact Mr. Guy V. Ford, Jr., Regulatory Assurance Manager, at (815) 415-2800.

ii::i"IV~

Harold T. Vinyard Plant Manager LaSalle County Station

Enclosure:

Licensee Event Report cc:

Regional Administrator - NRC Region Ill NRC Senior Resident Inspector - LaSalle County Station

NRC FORM366 (02-2018)

U.S. NUCLEAR REGULA TORY COMMISSION LICENSEE EVENT REPORT (LER)

(See Page 2 for required number of digits/characters for each block)

(See NUREG-1022, R.3 for instruction and guidance for completing this fom1 http://www nrc.gov/readinq-rm/doc*collections/nuregsistaff/sr1022/r3il APPROVED BY OMB: NO. 3150-0104 EXPIRES: 0313112020 E*tinated luden per rasponoe lo comp~ with this mandatory colloclion request 80 ho<n.

Reported lessens letrnad,,. in<orpora19d lnlo 1he licensing P'OC8SS and fod bact< lo lndusrt Send comments regwdlng burtlen aatimale lo lhe lnlormati:Jn Services Branch (T-2 F43), U.S. N<.<:lear RogulalDry Commlsoloo, Washlnglon, QC 20555-0001, a by a-maN lo lnfocollocts.R......,.@~gov, and lo 1he o..i. Oflieer, Ofli:e of lnlamotion end Regulaby Alfan, NEOB-10202. (3150<l104), Office of Management and Budge\\

Washinglcn, OC 20503.

If a means uoad lo Impose an Information coleclion does not

<ioplay a curan11y vaHd OMB contaf oonaer. h> NRC may not CO<OJct or sponsor. and a person Is not requilad lo ""'pond lo, the illormalion coletti>n.

3. Page 1

LaSalle County Station, Unit 1 05000373 OF 3

4. Title Two Main Steam Safety Relief Valves Failed lnservice Lift Inspection Pressure Test

5. Event Date

6. LER Number

7. Report Date

8. Other Facilities Involved I

Sequential I Rev Faclllty Name Docket Number Year Number No.

Month Day Year NA NA Month Day Year Faclflty Name Docket Number 02 27 18 2018 -

003 00 04 27 18 NA NA

9. Operating Mode

11. This Report Is Submitted Pursuant to the Requirements of 1 O CFR §: (Check all that apply)

D 20.2201 (bl 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)(iil 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) 1 D 20.2203(a><2>

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)(iil D 50.36(c)(1 )(ii}(A}

D 50. 73(a)(2}(v)(A)

D 73.71(a)(4)

D 20.2203(a)(2)(ii1>

D 50.36(c)(2}

D 50. 73(a)(2)(v)(B}

D 73. 71 (a)(5)

D 20.2203(a)(2)(iv)

D 50.46(a)(3)(ii)

D 50. 73(a)(2)(v}(C)

D 13.77(a)(1>

000 D 20.2203(a}(2)(v}

D 50.73(a}(2)(1)(A}

D 50.73(a)(2)(v)(D}

D 13.77(a)(2)(iil D 20.2203(a}(2)(vi)

~ 50. 73(a)(2)(i)(B)

D 50. 73(a}(2)(vii}

D 13.77<a><2><m>

D 50.73(a)(2)(i}(C)

D Other (Specify in Abstract below or in NRC Fom1 366A)

12. Licensee Contact for this LER Licensee Contact John Keenan, Engineering Director Telephone Number (Include Area Code)

(815) 415-3800 I Component I Manufacturar I Reportable to ICES RV C710 Yes

Cause

System Component Manufacturer I Reportable to ICES NA NA NA NA NA I

Cause

System x

AD

14. Supplemental Report Expected Month Day Year

15. Expected Submission Date 07 27 2018

~

Yes (If yes. complete 15. Expected Submission Date) D No Abstract (Limit to 1400 spaces, i.e., approximately 14 single-spaced typewritten lines)

During the February 2018 Unit 1 refueling outage, two main steam safety relief valves (SRV) did not pass Technical Specification (TS) Surveillance Requirement 3.4.4.1 and lnservice Testing (IST) Program lift pressure requirements. Both SRVs lifted below their expected lift pressures. On February 27, 2018, SRV 1 B21-F013R was required to lift within plus or minus three percent of 1205 psi (i.e., 1205 psi plus or minus 36.1 psi), but lifted at 1167 psi. On February 27, 2018, SRV 1 B21-F013U was required to lift within plus or minus three percent of 1150 psi (i.e., 1150 psi plus or minus 34.5 psi), but lifted at 1109 psi.

Multiple test failures are reportable under 10 CFR 50.73(a)(2)(i)(B) as an operation or condition prohibited by the plant's TS. Both SRVs lifted prior to their expected lift pressures, which is conservative regarding maintaining reactor pressure vessel over-pressure limits. Both SRVs were replaced during the outage. The cause of the event is under review by the vendor testing facility, and it will be reported in a supplement to this LER upon completion.

NRC FORM 366 (02-2018)

PLANT AND SYSTEM IDENTIFICATION

LaSalle County Station (LSCS) Unit 1 is a General Electric Boiling Water Reactor with 3546 Megawatts Thermal Rated Core Power.

The main steam safety relief valves (SRVs) are designed to prevent over-pressurization of the reactor pressure vessel (RPV) during transients and abnormal conditions, which protects against a failure of the reactor coolant pressure boundary (RCPB).

There are thirteen SRVs installed on the four main steam lines, which discharge near the bottom of the suppression pool to condense the steam through SRV tailpipes that exhaust beneath the suppression pool surface.

CONDITION PRIOR TO EVENT

Unit(s): 1 Reactor Mode(s): 5

DESCRIPTION

Date:

February 27, 2018 Mode(s) Name:

Refueling Time:

Power Level:

1520 CST 0 percent 00 During the February 2018 Unit 1 refueling outage, two main steam safety relief valves (SRV) did not pass Technical Specification (TS) Surveillance Requirement (SR) 3.4.4.1 and lnservice Testing (IST) Program lift pressure requirements. Both SRVs lifted below their expected lift pressures. On February 27, 2018, SRV 1 B21-F013R was required to lift within plus or minus three percent of 1205 psi (i.e.. 1205 psi plus or minus 36.1 psi), but lifted at 1167 psi. On February 27, 2018, SRV 1B21-F013U was required to lift within plus or minus three percent of 1150 psi (i.e., 1150 psi plus or minus 34.5 psi), but lifted at 1109 psi.

CAUSE

The cause of the event is under review by the vendor testing facility, and it will be reported in a supplement to this LER upon completion.

Station operating experience has shown a tendency for a portion of LSCS SRVs to experience minor setpoint drift sufficient to exceed the acceptance criteria of minus three percent over time. A license amendment request (LAR) was submitted to the NRC on February 27, 2018 to revise TS SR 3.4.4.1 to lower the setpoint tolerances for Unit 1 and Unit 2 SRVs. This proposed change would revise the SRV as-found lower tolerances from minus three percent to minus five percent to account for minor SRV setpoint drift in the conservative direction. This proposed change will reduce the unnecessarily restrictive surveillance requirement and will not impact the reliability of the SRVs or adversely impact their ability to perform their safety function. The change will reduce the number of TS SRV surveillance test failures for early lift pressure and preclude the submittal of previously reportable licensee event reports to the NRC due to setpoint drift in the low (conservative) direction.

REPORT ABILITY AND SAFETY ANALYSIS Multiple test failures are reportable under 10 CFR 50.73(a)(2)(i)(B) as an operation or condition prohibited by the plant's TS. Both SRVs lifted prior to their expected lift pressures, which is conservative regarding maintaining reactor pressure vessel over-pressure limits.

The safety significance of this condition was minimal. The out-of-tolerance lift pressures were discovered while Unit 1 was in Mode 5 during a refueling outage and the SRVs were not required to be operable. Both SRVs lifted prior to their expected lift pressures, which is conservative regarding maintaining reactor pressure vessel overpressure limits.

CORRECTIVE ACTIONS

Both SRVs 1 B21-F013R and 1B21-F013U were replaced during the outage. The cause of the event is under review by the vendor testing laboratory.

PREVIOUS OCCURRENCES

LER Unit 2 37 4-2015-002-01:

YEAR 2018 SEQUENTIAL NUMBER 003 REV NO.

00 During the February 2015 Unit 2 refueling outage L2R15, two main steam safety relief valves (SRV) did not pass TS Surveillance Requirement 3.4.4.1 and lnservice Testing Program lift pressure requirements. Both SRVs lifted below their expected lift pressures and were replaced during the outage. A failure analysis was conducted by a vendor testing laboratory, but the cause for the valves lifting below their set-point was indeterminate.

LER Unit 2 374-2017-004-01:

During the February 2017 Unit 2 refueling outage, two main steam safety relief valves (SRV) did not pass TS Surveillance Requirement 3.4.4.1 and lnservice Testing Program lift pressure requirements. Both SRVs lifted below their expected lift pressures and were replaced during the outage. A failure analysis was conducted by a vendor testing laboratory, but the cause for the valves lifting below their set-point was indeterminate.

COMPONENT FAILIRE DATA Manufacturer: Crosby Device: Main Steam Safety Relief Valves, ASME Section Ill, Class 1 Component ID: Style HB-65-BP, Size 6R10 NRC FORM 356A (04-2017)

Page _3_ of _3_