05000454/LER-2015-001, Inadequate Application of Technical Specifications Related to Main Steam Isolation Valves and Actuator Trains
| ML15070A013 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 03/11/2015 |
| From: | Kearney F Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 1.10.0101 (1D.101), 2.07.0100 (5A.108), BYRON 2015-0030 LER 15-001-00 | |
| Download: ML15070A013 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 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) 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)(v), Loss of Safety Function |
| 4542015001R00 - NRC Website | |
text
Byron Generating Station Exelon Generation 4450 North German Church Rd Byron, IL 61010-9794 March 11,2015 LTR:
BYRON 201 5-0030 File:
1.10.0101 (1D.101) 2.07.01 00 (5A.108)
United States Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-000 1 Byron Station, Unit 1 Facility Operating License No. NPF-37 NRC Docket No. STN 50-454 www.exeloncorocom
Subject:
Licensee Event Report (LER) 454-2015-001-00, Byron Unit 1, Inadequate Application of Technical Specifications Related to Main Steam Isolation Valves and Actuator Trains Enclosed is Byron Station Licensee Event Report (LER) No. 454-2015-001-00 regarding previous occurrences in the prior three years when a Main Steam Isolation Valve actuator train was inoperable and the inoperable train was not restored within the required Technical Specification 3.7.2, Condition A, 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time. This condition is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) for any operation or condition which is prohibited by the plants Technical Specifications.
There are no regulatory commitments in this report.
Should you have any questions concerning this submittal, please contact Mr. Douglas Spitzer, Regulatory Assurance Manager, at (815) 406-2800.
Respectfully, FAK/GC/sg
Enclosure:
LER 454-2015-001-00 cc:
Regional Administrator NRC Region Ill NRC Senior Resident Inspector Byron Generating Station Site Vice President Byron Generating Station
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 0113112017 (02-201 4)
Estimated burden per response to comply with this mandatory cotection 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 FO(A, Privacy and Information Cndections LICENSEE EVENT REPORT (LER)
Branch (T-5 F53), U.S. Nuclear Regalatory Commission, Washington. DC 20555-0001, or by internet e-mail to lnt000llects.Resoeroe@nrc,gov, and to the Desk Officer, Otfice of Information and (See Page 2 for required number of RegulatoryAffairs, 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 currenhy valid 0MB digits/characters for each block) contiol number the NRC may not conduct or sponsor, arid a person is not required to respond to.
the information colecifon.
- 1. FACILIT NAME
- 2. DOCKET NUMBER
- 13. PAGE Byron Station, Unit 1 05000454 1
OF 4
I. flTLE Byron Unit 1, Inadequate Application of Technical Specifications Related to Main Steam Isolation Valves and Actuator Trains.
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED FACILITI NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEUAL EV MONTH DAY YEAR Byron Station, Unit 2 05000455 FACILITY NAME DOCKET NUMBER 01 11 2015 2015 001
- - 00 03 11 2015 N/A N/A
- 9. OPERA11NG MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
El 20.2201(b)
[1 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii)
El 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
El 50.73(a)(2)Qii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71(a)(4) 100 El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71 (a)(5)
El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi) 50.73(a)(2)Q)(B)
El 50.73(a)(2)(v)(D)
SpacifyioAbstractbataworin
- 12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT Douglas Spitzer Manager, Byron Regulatory Assurance
- 13. COMPLETE
CAUSE
SYSTEM COMPONENT N/A N/A N/A
- 14. SUPPLEMENTAL REPORT EXPECTED BSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On January 11, 2015, at 2055 hours0.0238 days <br />0.571 hours <br />0.0034 weeks <br />7.819275e-4 months <br />, Byron Station Unit 2 entered Technical Specification (TS) 3.7.2, Main Steam Isolation Valves (MSIVs), Condition A, with an associated 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time for the Unit 2, Train A MSIV due to one of the associated redundant actuator trains being inoperable. This action was consistent with an October 19, 2006 NRC staff interpretation that Surveillance Requirement 3.7.2.2 requires both actuator trains for a single valve to be tested and an MSIV shall be declared inoperable when one of its associated actuator trains is inoperable. A subsequent Byron Station extent of condition review identified two previous occurrences in the prior three years when an actuator train for an MSIV was inoperable and the inoperable train was not restored within the required 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time.
In these instances, TS requirements of 3.7.2 were inadequately applied and should have been imposed. This event is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) for any operation or condition which is prohibited by the plants Technical Specifications.
The cause of the event was a departure from Byron Stations previous practice to one that was based on the October 19, 2006 NRC position in regard to entering TS 3.7.2, Condition A, under similar conditions. Corrective actions included communicating to operating crews, revising procedures and implementation of new TS for MS lVs.
I CLO.IMUN NUMDC< inciude Area Code) 1(815) 406-2800 El YES (Ifyes, complete 15. EXPECTED SUBMISSION DATE)
NO NRC FORM 366 (02-2014)
A.
Plant Condition Prior to Event Event Date/Time: January 11, 2015 / 2055 hours0.0238 days <br />0.571 hours <br />0.0034 weeks <br />7.819275e-4 months <br /> CST Unit 1
- - Mode 1 Mode 1 Power 100 percent Unit 2
- - Mode 1 Mode 1 Power 100 percent Reactor Coolant System [AB]: Normal operating temperature and pressure. There was no inoperable equipment that contributed to this event.
B.
Description of Event
On January 11, 2015, at 2055 hours0.0238 days <br />0.571 hours <br />0.0034 weeks <br />7.819275e-4 months <br />, the Byron Station Unit 2, Train A (2A), Main Steam Isolation Valve (MSIV) was declared inoperable due to the inoperability of one of the associated redundant actuator trains. Byron Station Operations immediately entered Technical Specification (TS) 3.7.2, Main Steam Isolation Valves (MSIVs), Condition A, which requires that with one MSIV inoperable in Mode 1, restore the MSIV to Operable status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
If the inoperable MSIV is not restored to Operable status, Condition B must be entered.
Condition B requires that the unit be placed in Mode 2 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Byron Station successfully restored the inoperable MSIV to Operable status prior to the expiration of the TS 3.7.2, Condition A, 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time.
On January 13, 2015 a Byron Station system engineer initiated Issue Report (IR) 2436822 to document that declaring a MSIV inoperable due to a condition that affects only one accumulatorlhydraulic train may not have been performed in the recent past. The IR referenced a specific prior occurrence on June 30, 2014 associated with the 2A MSIV Accumulator (reference JR 1676838). This JR prompted a Byron Station action to review for extent of condition for a period of three years back from January 11, 2015.
The extent of condition review identified two occurrences at Byron Station in the prior three years where an accumulator/hydraulic train for an MSIV was inoperable and the inoperable train was not restored within the 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time required by TS 3.7.2, Condition A. These occurrences are noted as follows:
1.
June 30, 2014: Byron Station Unit 2, Nitrogen leakage from 2A MSIV Standby Accumulator (reference IR 1676838). During System trending, an engineer observed a minor and longer term decrease in 2A MSIV standby pressure when compared with the Active Train accumulator pressure. Follow-up determined a nitrogen leak of unknown quantity, but the accumulator nitrogen pre-charge was low and, therefore, the accumulator was inoperable. The accumulator was restored to Operable status on July 3, 2015. This restoration time exceeded the 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> completion time of TS 3.7.2, Condition A.
2.
September25, 2013: Byron Station Unit 1, lB MSIV Has No Oil Level in Sight Glass (reference IR 1563273). Operations identified that the 1 B MSIV had no oil level visible in the oil sight glass. The I B MSIV active side accumulator had a nitrogen pre-charge check performed under Work Order 01083671 on September 27, 2013. The pre-charge check found the active side accumulator pre-charge was lower than allowed. Proper pre-charge was established and the accumulator restored on September 30, 2015.
This restoration time exceeded the 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> completion time of TS 3.7.2, Condition A
This event is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) for any operation or condition which is prohibited by the plants Technical Specifications due to TS 3.7.2 Condition A Required Action not being completed within the Completion Time.
The January 11 2015 entry into Byron TS 3.7.2, Condition A was predicated on industry experience and an NRC staff interpretation that Surveillance Requirement 3.7.2.2 requires both actuator trains for a single valve to be tested. (Reference NRC Memorandum, Operability Determination for the Callaway Plant Technical Specifications Requirements When One Main Steam Isolation Valve Actuator Train is Removed from Service, dated October 19, 2006 (ADAMS Accession Number MLO61 730396).
On the event date, Byron TS 3.7.2 did not specifically address or reflect the two independent actuator trains for one MSIV. Inoperability of one of the two actuator trains associated with an MSIV does not by itself make the valve incapable of closing since the remaining Operable actuator train can alone effect valve closure on demand.
The NRC staff interpretation results in declaring an MSIV inoperable for those plants with dual MSIV actuator trains when one actuator train is inoperable. The existing Completion time for an inoperable MSIV does not typically provide a reasonable amount of time to effect repairs to one inoperable actuator train. Declaring an MSIV inoperable and having to enter the Condition(s) and Required Action(s) for an MSIV inoperable due only to one inoperable actuator train is unnecessarily restrictive. To address this condition, Byron Station had previously submitted a License Amendment Request (LAR) on August 21, 2013 (ADAMS Accession Number ML13235A095) to incorporate requirements specifically for the MSIV actuator trains within TS 3.7.2 such that the specification would include Conditions and Required Actions to address inoperable MSIV actuator trains. This LAR was approved by the NRC for Byron Station on January 30, 2015.
C.
Cause of Event
The cause of the event was a departure from Byron Stations previous practice to one that was based on the October 19, 2006 NRC position in regard to entering TS 3.7.2, Condition A, under similar conditions. The previous practice was based on the following factors:
- 1. The original TS did not explicitly address the MSIV actuator trains.
- 2. The redundancy in the MSIV actuator design permits an MSIV to close on demand, with one actuator train unavailable.
D.
Safety Significance
This event is not considered an event or condition that could have prevented fulfillment of a safety function.
The Byron events of June 30, 2014 and September 25, 2013 document a single actuator train as inoperable for three days and five days respectively. The probabilistic risk analysis (PRA) used to validate the acceptability of the 7 day allowed Completion Time for the NRC approved Byron LAR bounds these events E.
Corrective Actions
Byron Operations communicated the MSIV operability position to operating crews on January 12, 2015.
Byron Station had previously submitted a LAR on August 21, 2013 to incorporate Conditions and Required Actions to address inoperable MSIV actuator trains within TS 3.7.2. This LAR was approved by the NRC for Byron Station on January 30, 2015. Byron implemented the new TS on February 2, 2015. Operating procedures for the TS change have been approved and implemented.
NRC FORM 66A (02-2014)U.S. NUCLEAR REGULATORY COMMISSION (02.2014)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE SEQUENTIAL REV YEAR NUMBER NO.
Byron Station, Unit 1 05000454 4
OF 4
2015 001 00 NARRA11VE F.
Previous Occurrences
No previous similar events are known.