05000397/LER-2015-007, Regarding Reactor Building Pressure Greater than Technical Specifications Requirement

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Regarding Reactor Building Pressure Greater than Technical Specifications Requirement
ML16007A756
Person / Time
Site: Columbia Energy Northwest icon.png
Issue date: 01/07/2016
From: Hettel W
Energy Northwest
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
GO2-16-010 LER 15-007-00
Download: ML16007A756 (4)
v • d • e


LER-2015-007, Regarding Reactor Building Pressure Greater than Technical Specifications Requirement
Event date:
Report date:
Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function
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)(i)(B), Prohibited by Technical Specifications
3972015007R00 - NRC Website
v • d • e

text

WG Hettel EriERGY Columbia Generating Station N0RTHVVEST wghettei@ energy-northwest.com 10 CFR 50.73 Us. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001

Subject:

COLUMBIA GENERATING STATION, DOCKET NO. 50-397 LICENSEE EVENT REPORT NO. 2015-007-00

Dear Sir or Madam:

Transmitted herewith is Licensee Event Report No. 201 5-007-00 for Columbia Generating Station. This report is submitted pursuant to 50.73(a)(2)(v)(C) and 50.73(a)(2)(v)(D).

There are no commitments being made to the NRC by this letter.

If you have any questions or require additional information, please contact Ms. D.M. Wolfgramm, Regulatory Compliance Supervisor, at (509) 377-4792.

Executed on W.G. Hettel Vice President, Operations

Enclosure:

Licensee Event Report 201 5-007-00 cc: NRC Region IV Administrator NRC NRR Project Manager NRC Senior Resident Inspector/988C CD Sonoda BPA/1 399 WA Horin Winston & Strawn January 7, 2016 GO2-16-010

26158 R6 NRC Form 366 (01-2014)

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (01-2014)

LICENSEE EVENT REPORT (LER)

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

APPROVED BY OMB: NO. 3150-0104 EXPIRES 01/31//2017 Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.

Reported lessons learned are incorporated into the licensing process and fed back to industry.

Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to infocollects.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 OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

1. FACILITY NAME Columbia Generating Station
2. DOCKET NUMBER 05000 397
3. PAGE 1

OF 3

4. TITLE REACTOR BUILDING PRESSURE GREATER THAN TECHNICAL SPECIFICATIONS REQUIREMENT
5. EVENT DATE
6. LER NUMBER
7. REPORT DATE
8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REV NO.

MONTH DAY YEAR FACILITY NAME N/A DOCKET NUMBER 05000 11 09 2015 2015 - 007 00 01 07 2016 FACILITY NAME N/A DOCKET NUMBER 05000

9. OPERATING MODE
11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1 20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203 (a)(1) 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i) 50.36(c)(1)(i)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A)
10. POWER LEVEL 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 100 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)

OTHER 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)

Specify in Abstract below or in

Plant Conditions

At the time of the event the plant was operating in Mode 1 at 100% power. The Division 1 Standby Gas Treatment (SGT) [BH] system was inoperable and unavailable due to annual system maintenance.

Event Description

On November 9, 2015 at 20:40 PST, Secondary Containment [NG] became inoperable as pressure increased above the -0.25 inches water gauge (inwg) required by Technical Specification (TS) Surveillance Requirement (SR) 3.6.4.1.1. This was due to failure of a power supply (E-E/S-299) [JX], which supplied power to the Secondary Containment Division 2 Pressure Controller (REA-DPIC-1B) [PDC]. Consequently, the Division 2 Reactor Building Exhaust Fan (REA-FN-1B) [FAN] dropped to minimum exhaust flow, and for approximately seven minutes, the Secondary Containment pressure rose above -0.25 inwg, which exceeded the TS limit.

High pressure alarms were received in the Control Room and Operators proceeded to manually start the safety related Division 2 Standby Gas Treatment [BH] lead fan (SGT-FN-1B2) [FAN] to restore negative pressure. The flow controller for this lead fan (SGT-DPIC-1B2) [PDC] also had failed as a result of the loss of power, causing its vortex damper (SGT-AD-1B2) [FAN] to remain fully open, resulting in the restoration of Secondary Containment pressure to within TS limits. The Division 1 Reactor Building Heating, Ventilation and Air Conditioning System (HVAC) [VA] was then placed in automatic mode, which maintained Secondary Containment pressure within TS limits, thus allowing Operators to manually secure SGT-FN-1B2.

During the event, there were no radioactive releases or other safety system malfunctions, other than the systems involved in the inoperability of Secondary Containment as affected by the electrical power supply failure.

Cause

Secondary Containment was lost when power supply E-E/S-299 failed. The direct cause for the loss of the power supply E-E/S-299 was an inappropriate lug size installed within the fuse block. The lug used was thicker than required for the fuse block connection and a tight mechanical connection in the lug landing area did not exist, which resulted in a loose fuse block termination. The station determined that the apparent cause of the event was a latent human performance error, in which an incorrectly sized lug was installed during initial construction. A review of the work history for E-E/S-299 showed that no work had been performed on this component after initial installation.

Immediate Corrective Action

Operators manually started the Division 1 SGT lead fan to restore Secondary Containment pressure. The lead fan operated at max flow (due to the failure of E-E/S-299) resulting in the restoration of Secondary Containment pressure to within TS limits. Operators then placed Division 1 Reactor Building HVAC into automatic to maintain Secondary Containment pressure within TS limits.

A temporary alteration in support of maintenance was performed to provide temporary power while a new terminal block for E-E/S-299 was installed.

26158A R3

WG Hettel EriERGY Columbia Generating Station N0RTHVVEST wghettei@ energy-northwest.com 10 CFR 50.73 Us. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001

Subject:

COLUMBIA GENERATING STATION, DOCKET NO. 50-397 LICENSEE EVENT REPORT NO. 2015-007-00

Dear Sir or Madam:

Transmitted herewith is Licensee Event Report No. 201 5-007-00 for Columbia Generating Station. This report is submitted pursuant to 50.73(a)(2)(v)(C) and 50.73(a)(2)(v)(D).

There are no commitments being made to the NRC by this letter.

If you have any questions or require additional information, please contact Ms. D.M. Wolfgramm, Regulatory Compliance Supervisor, at (509) 377-4792.

Executed on W.G. Hettel Vice President, Operations

Enclosure:

Licensee Event Report 201 5-007-00 cc: NRC Region IV Administrator NRC NRR Project Manager NRC Senior Resident Inspector/988C CD Sonoda BPA/1 399 WA Horin Winston & Strawn January 7, 2016 GO2-16-010

26158 R6 NRC Form 366 (01-2014)

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (01-2014)

LICENSEE EVENT REPORT (LER)

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

APPROVED BY OMB: NO. 3150-0104 EXPIRES 01/31//2017 Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.

Reported lessons learned are incorporated into the licensing process and fed back to industry.

Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to infocollects.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 OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

1. FACILITY NAME Columbia Generating Station
2. DOCKET NUMBER 05000 397
3. PAGE 1

OF 3

4. TITLE REACTOR BUILDING PRESSURE GREATER THAN TECHNICAL SPECIFICATIONS REQUIREMENT
5. EVENT DATE
6. LER NUMBER
7. REPORT DATE
8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REV NO.

MONTH DAY YEAR FACILITY NAME N/A DOCKET NUMBER 05000 11 09 2015 2015 - 007 00 01 07 2016 FACILITY NAME N/A DOCKET NUMBER 05000

9. OPERATING MODE
11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1 20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203 (a)(1) 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i) 50.36(c)(1)(i)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A)
10. POWER LEVEL 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 100 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)

OTHER 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)

Specify in Abstract below or in

Plant Conditions

At the time of the event the plant was operating in Mode 1 at 100% power. The Division 1 Standby Gas Treatment (SGT) [BH] system was inoperable and unavailable due to annual system maintenance.

Event Description

On November 9, 2015 at 20:40 PST, Secondary Containment [NG] became inoperable as pressure increased above the -0.25 inches water gauge (inwg) required by Technical Specification (TS) Surveillance Requirement (SR) 3.6.4.1.1. This was due to failure of a power supply (E-E/S-299) [JX], which supplied power to the Secondary Containment Division 2 Pressure Controller (REA-DPIC-1B) [PDC]. Consequently, the Division 2 Reactor Building Exhaust Fan (REA-FN-1B) [FAN] dropped to minimum exhaust flow, and for approximately seven minutes, the Secondary Containment pressure rose above -0.25 inwg, which exceeded the TS limit.

High pressure alarms were received in the Control Room and Operators proceeded to manually start the safety related Division 2 Standby Gas Treatment [BH] lead fan (SGT-FN-1B2) [FAN] to restore negative pressure. The flow controller for this lead fan (SGT-DPIC-1B2) [PDC] also had failed as a result of the loss of power, causing its vortex damper (SGT-AD-1B2) [FAN] to remain fully open, resulting in the restoration of Secondary Containment pressure to within TS limits. The Division 1 Reactor Building Heating, Ventilation and Air Conditioning System (HVAC) [VA] was then placed in automatic mode, which maintained Secondary Containment pressure within TS limits, thus allowing Operators to manually secure SGT-FN-1B2.

During the event, there were no radioactive releases or other safety system malfunctions, other than the systems involved in the inoperability of Secondary Containment as affected by the electrical power supply failure.

Cause

Secondary Containment was lost when power supply E-E/S-299 failed. The direct cause for the loss of the power supply E-E/S-299 was an inappropriate lug size installed within the fuse block. The lug used was thicker than required for the fuse block connection and a tight mechanical connection in the lug landing area did not exist, which resulted in a loose fuse block termination. The station determined that the apparent cause of the event was a latent human performance error, in which an incorrectly sized lug was installed during initial construction. A review of the work history for E-E/S-299 showed that no work had been performed on this component after initial installation.

Immediate Corrective Action

Operators manually started the Division 1 SGT lead fan to restore Secondary Containment pressure. The lead fan operated at max flow (due to the failure of E-E/S-299) resulting in the restoration of Secondary Containment pressure to within TS limits. Operators then placed Division 1 Reactor Building HVAC into automatic to maintain Secondary Containment pressure within TS limits.

A temporary alteration in support of maintenance was performed to provide temporary power while a new terminal block for E-E/S-299 was installed.

26158A R3

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