05000333/LER-2014-002, Regarding Secondary Containment Vacuum Below Technical Specification Limit
| ML14353A269 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 12/19/2014 |
| From: | Brian Sullivan Entergy Nuclear Northeast, Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| JAFP-14-0147 LER 14-002-00 | |
| Download: ML14353A269 (5) | |
| 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 |
| 3332014002R00 - NRC Website | |
text
- -=--Entergy JAFP-14-0147 December 19, 2014 United States Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001 Entergy Nuclear Northeast Entergy Nuclear Operations, Inc.
James A. FitzPatrick NPP P.O. Box 110 Lycoming, NY 13093 Tel 315-349-6024 Fax 315-349-6480 Brian R. Sullivan Site Vice President - JAF
Subject:
LER: 2014-002, Secondary Containment Vacuum Below Technical Specification Limit
Dear Sir or Madam:
James A. FitzPatrick Nuclear Power Plant Docket No. 50-333 License No. DPR-59 This report is submitted in accordance with 1 O CFR 50.73(a)(2)(v)(C).
There are no commitments contained in this report.
Questions concerning this report may be addressed to Mr. Chris M. Adner, Regulatory Assurance Manager, at (315) 349-6766.
Sincerely, r
BRS/CMA/mh Enclosure(s): JAF LER 2014-002, Reactor Building Vacuum Below Technical Specification Limit cc:
USNRC, Region 1 USNRC, Project Directorate USNRC, Resident Inspector INPO Records Center (ICES)
NRC FORM 366 (02-2014)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (01-2014)
LICENSEE EVENT REPORT (LER)
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 James A. FitzPatrick Nuclear Power Plant
- 2. DOCKET NUMBER 05000333
- 3. PAGE 1 OF 4
- 4. TITLE Secondary Containment Vacuum Below Technical Specification Limit
- 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 N/A 10 28 2014 2014 - 002 - 00 12 19 2014 FACILITY NAME N/A DOCKET NUMBER N/A
- 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
=
Background===
The Secondary Containment [EIIS identifier: NG] is a structure comprised of the reactor building that surrounds the primary containment and refuel equipment. Its safety function is designed to provide containment for postulated accident scenarios: loss-of-coolant accident and refueling accident. This structure forms a control volume that serves to hold up and dilute the fission products. Since pressure may increase in Secondary Containment relative to the environmental pressure, it was designed to include a differential pressure vacuum such that external atmosphere would leak into containment rather than fission products leak out.
The systems which maintain a differential pressure vacuum inside Secondary Containment include the normal Reactor Building Ventilation (RBV) system [VA] and the safety-related Standby Gas Treatment (SBGT) system [BH]. The RBV has two sets of exhaust fans. The A set includes 66FN-12A with damper 66AOD-104A and 66FN-13A with damper 66AOD-106A. During a postulated accident scenario the normal RBV isolates by closing two intake isolation valves (66AOV-100A and 66AOV-100B) and two exhaust isolation valves (66AOV-101A and 66AOV-101B). At the same time SBGT initiates in order to filter gas from Secondary Containment to the environment. SBGT has the capacity to maintain the differential pressure vacuum.
Event Description
At 1655 on October 28, 2014, James A. FitzPatrick Nuclear Power Plant (JAF) was operating at 100 percent power when the RBV was placed in isolate mode and SBGT was initiated. The differential pressure decreased below 0.25 inches water vacuum. At 1708, RBV was being returned to its normal non-isolated line-up with the A RBV train in service following planned maintenance. When SBGT was secured and A RBV was operating by itself, the reactor building differential pressure dropped below 0.25 inches water vacuum again. The B RBV train was placed in service and the Secondary Containment differential pressure returned to 0.25 inches water vacuum. The period of time that the differential pressure was below 0.25 inches water vacuum in both cases was approximately one minute.
During the period in which Secondary Containment did not meet the Technical Specification (TS) Surveillance Requirement (SR) 3.6.4.1.1 for differential pressure, the Limiting Condition of Operation (LCO) allowed by the TS was not met. Therefore, Secondary Containment was Inoperable. Restoration of the LCO was completed within the allowed action completion time of the TS. An NRC notification was made by ENS 50579. This Licensing Event Report (LER) is being submitted per 10 CFR 50.73(a)(2)(v)(C) as a condition that could have prevented the fulfillment of safety function to control the release of radioactive material.
Event Analysis
Isolation sequence: The time it takes for the exhaust isolation valves to close is 5 seconds while the intake isolations valves close in 15 seconds during a RBV isolation sequence. During this time period, air would enter Secondary Containment without air being removed. As a result, the differential pressure decreases.
Damper misalignment: Previously, on August 28, 2014, the damper 66AOD-106A was found not full open with the fan running. Tracking items to investigate and correct were initiated in the work management system.
Repairs had not been performed prior to the event reported by this LER.
At 1708 on October 28, the RBV A train did not maintain Secondary Containment differential pressure above 0.25 inches water vacuum because the damper 66AOD-106A did not fully open. The troubleshooting identified that the top operator 66AOD-106A1(OP) did not stroke because the air piston diaphragm needed replacement.
=
Background===
The Secondary Containment [EIIS identifier: NG] is a structure comprised of the reactor building that surrounds the primary containment and refuel equipment. Its safety function is designed to provide containment for postulated accident scenarios: loss-of-coolant accident and refueling accident. This structure forms a control volume that serves to hold up and dilute the fission products. Since pressure may increase in Secondary Containment relative to the environmental pressure, it was designed to include a differential pressure vacuum such that external atmosphere would leak into containment rather than fission products leak out.
The systems which maintain a differential pressure vacuum inside Secondary Containment include the normal Reactor Building Ventilation (RBV) system [VA] and the safety-related Standby Gas Treatment (SBGT) system [BH]. The RBV has two sets of exhaust fans. The A set includes 66FN-12A with damper 66AOD-104A and 66FN-13A with damper 66AOD-106A. During a postulated accident scenario the normal RBV isolates by closing two intake isolation valves (66AOV-100A and 66AOV-100B) and two exhaust isolation valves (66AOV-101A and 66AOV-101B). At the same time SBGT initiates in order to filter gas from Secondary Containment to the environment. SBGT has the capacity to maintain the differential pressure vacuum.
Event Description
At 1655 on October 28, 2014, James A. FitzPatrick Nuclear Power Plant (JAF) was operating at 100 percent power when the RBV was placed in isolate mode and SBGT was initiated. The differential pressure decreased below 0.25 inches water vacuum. At 1708, RBV was being returned to its normal non-isolated line-up with the A RBV train in service following planned maintenance. When SBGT was secured and A RBV was operating by itself, the reactor building differential pressure dropped below 0.25 inches water vacuum again. The B RBV train was placed in service and the Secondary Containment differential pressure returned to 0.25 inches water vacuum. The period of time that the differential pressure was below 0.25 inches water vacuum in both cases was approximately one minute.
During the period in which Secondary Containment did not meet the Technical Specification (TS) Surveillance Requirement (SR) 3.6.4.1.1 for differential pressure, the Limiting Condition of Operation (LCO) allowed by the TS was not met. Therefore, Secondary Containment was Inoperable. Restoration of the LCO was completed within the allowed action completion time of the TS. An NRC notification was made by ENS 50579. This Licensing Event Report (LER) is being submitted per 10 CFR 50.73(a)(2)(v)(C) as a condition that could have prevented the fulfillment of safety function to control the release of radioactive material.
Event Analysis
Isolation sequence: The time it takes for the exhaust isolation valves to close is 5 seconds while the intake isolations valves close in 15 seconds during a RBV isolation sequence. During this time period, air would enter Secondary Containment without air being removed. As a result, the differential pressure decreases.
Damper misalignment: Previously, on August 28, 2014, the damper 66AOD-106A was found not full open with the fan running. Tracking items to investigate and correct were initiated in the work management system.
Repairs had not been performed prior to the event reported by this LER.
At 1708 on October 28, the RBV A train did not maintain Secondary Containment differential pressure above 0.25 inches water vacuum because the damper 66AOD-106A did not fully open. The troubleshooting identified that the top operator 66AOD-106A1(OP) did not stroke because the air piston diaphragm needed replacement. U.S. NUCLEAR REGULATORY COMMISSIONN (01-2014)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE James A. FitzPatrick Nuclear Power Plant 05000333 YEAR SEQUENTIAL NUMBER REV N0.
3 of 4 2014 -
002
00 Cause
Secondary Containment differential pressure fell below 0.25 inches water vacuum when the discharge isolation damper 66AOD-106A failed to reposition because the damper operator 66AOD-106A1(OP) contained a defective diaphragm. Also, the difference in closure time between intake and exhaust isolation valves caused differential pressure to decrease below 0.25 inches water vacuum.
Similar Events
In the past three years there have been several instances when Secondary Containment differential pressure has been below the 0.25 inch of vacuum water gauge for short durations. There are three types of causes:
- 1) High wind conditions, TS Bases 3.6.4.1.1 states, Momentary transients on the installed instrumentation due to gusty wind conditions are considered acceptable.
- 2) Isolation sequence, of RBV creates a momentary change in differential pressure.
- 3) Equipment malfunction, the event being reported by this LER.
External events:
Cooper Nuclear Station: LER 2014-001, Secondary Containment Declared Inoperable due to Rise in Differential Pressure when Operator inadvertently closed exhaust damper (ML14070A363).
Columbia Generating Station: LER 2013-007-01, Secondary Containment Pressure Exceeded During Severe Weather Conditions (ML14160B127).
Columbia Generating Station: LER 2014-001-01, Secondary Containment Pressure (ML14161A144).
FAILED COMPONENT IDENTIFICATION:
Manufacturer:
Arrow United Industries Manufacturer Model Number:
454 NPRDS Manufacturer Code:
A494 NPRDS Component Code:
DMP FitzPatrick Component ID:
Corrective Actions
Completed Actions Revise ST-40D, Daily Surveillances. Improve procedure definition for applicability of SR.
Repair Refuel Floor Exhaust Fan A Discharge isolation damper top blade operator 66AOD-106A1(OP)
Future Actions The pressure transients caused by RBV isolation sequence has been entered into the Corrective Action Process
Safety Significance
Nuclear safety This event did not have any actual or potential impact on nuclear safety.
Radiological safety There was no radiological consequence during this event.
The potential for a radiological consequence is only applicable during the time that Secondary Containment was below 0.25 inches water vacuum differential pressure. When this condition had occurred at JAF it was U.S. NUCLEAR REGULATORY COMMISSIONN (01-2014)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE James A. FitzPatrick Nuclear Power Plant 05000333 YEAR SEQUENTIAL NUMBER REV N0.
4 of 4 2014 -
002 00 momentary excursions.
Secondary Containment maintains a differential pressure vacuum by two of four RBV exhaust fans or one of two SBGT trains. During a postulated accident scenario RBV is placed in isolation and the SBGT is used to maintain differential pressure. During this event, one of four RBV exhaust fans were affected. The condition does not adversely impact that ability of RBV to isolate or SBGT to initiate. Therefore, the capability of Secondary Containment to mitigate the consequence of an accident is unaffected by this deficiency.
Industrial safety This event did not have any actual or potential impact on industrial safety.
References Condition Report: CR-JAF-2014-04535, August 28, 2014, damper failure Condition Report: CR-JAF-2014-06498, Apparent Cause Evaluation Condition Report: CR-JAF-2014-06600, Damper 66AOD-106A repair Condition Report: CR-JAF-2014-07227, RBV pressure transient