05000461/LER-2016-003, Regarding Bypassing Both Divisions of Reactor Water Cleanup Leak Detection System Is a Reportable Loss of Safety Function
| ML16146A543 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 05/23/2016 |
| From: | Stoner T Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| SRRS 5A.108, U-604283 LER 16-003-00 | |
| Download: ML16146A543 (5) | |
| 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) |
| 4612016003R00 - NRC Website | |
text
Exelon Generation Clinton Power Station 8401 Power Road Clinton, IL 61727 U-604283 May 23, 2016 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001
Subject:
Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461 Licensee Event Report 2016-003-00 10CFR50.73 SRRS 5A.108 Enclosed is Licensee Event Report (LER) 2016-003-00: Bypassing Both Divisions of Reactor Water Cleanup Leak Detection System is a Reportable Loss of Safety Function. This report is being submitted in accordance with the requirements of 10 CFR 50.73.
There are no regulatory commitments contained in this report.
Should you have any questions concerning this report, please contact Mr. Dale Shelton, Regulatory Assurance Manager, at (217) 937-2800.
Respectfully,
~~~ :::>
Theodore R. Stoner Site Vice President Clinton Power Station
- KP/cac Attachment: Licensee Event Report 2016-003-00 cc:
Regional Administrator-NRC Region Ill NRC Senior Resident Inspector - Clinton Power Station Office of Nuclear Facility Safety -
Illinois Emergency Management Agency
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 (11-2015)
, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Clinton Power Station, Unit 1 05000461 1 OF 4
- 4. TITLE Bypassing Both Divisions of Reactor Water Cleanup Leak Detection System is a Reportable Loss of Safety Function
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED YEAR I SEQUENTIAL I REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR NUMBER NO.
MONTH DAY YEAR 05000 FACILITY NAME DOCKET NUMBER 03 24 2016 2016 - 003
- - 00 5
23 2016 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
D 20.2201(b)
D 20.22oa(a)(a)(i)
D 50.73(a)(2)(ii)(A)
D 50.73(a)(2)(viii)(A) 1 D
20.2201 (dl D
20.22oa(a)(a)(iil D
50.73(a)(2)(ii)(B)
D 50.73(a)(2)(viii)(B)
D 20.22os(a)(1)
D 20.22oa(a)(4)
D so.1a(a)(2)(iii)
D 50.73(a)(2)(ix)(A)
D 20.22os(a)(2)cil D
50.36(c)(1)(i)(A)
D 50.73(a)(2)(iv)(A)
D 50.73(a)(2)(x)
- 10. POWER LEVEL D
20.22os(a)<2l(iil D
50.36(c)(1 )(ii)(A)
D 50.73(a)(2)(v)(A)
D 1s.11ca)(4l D
20.22os(a)(2)(m)
D so.a6(c)(2)
D 50.73(a)(2)(v)(B)
D 1a.71 (a)(s)
D 20.2203(a)(2)(iv)
D so.46(aJcaioiJ.
18] 50.73(a)(2)(v)(C)
D 1s.11c~Jc1J 099 D
20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
Dso.73(a)(2)(v)(D)
D 1s.11caJ(2)(iJ D
20.2203(a)(2)(vi)
D 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 1s.11ca.J(2)(iil D
50.73(a)(2)(i)(C)
D OTHER Specify in Abstract below or in 2016 003 00 1159: Placed RT F/O 'B' on Service following backwash of 'A' F/O.
1202: Placed RT F/O 'A' on Service following backwash.
1204: Placed both divisions of RT LO bypass switches in Normal. Performed channel check SAT. Exit LCO 3.3.6.1 Required Action 0.1 and E.1 actions.
- 3. PAGE 3
OF An evaluation determined that placing both divisions of the RT LO switches in the Bypass position represented a loss of safety function that was not part of a planned evolution for maintenance or testing. Backwashing and pre-coating a RT F/O, as indicated in the Operations Log, is a normal system operation and not considered maintenance. Therefore, placing both divisions of RT LO switches in Bypass was reportable. The Updated Safety Analysis Report (USAR), the TS Bases, and NRG reporting requirements were reviewed as part of an evaluation regarding event
reportability
Based on this review, it was determined that the RT LO system is credited to mitigate a break in the RT system piping inside containment accident as described in USAR Chapter 6. As a result, it was concluded that placing both divisions of RT LO switches in Bypass as described in this LER, represented a condition that could have prevented the fulfillment of the safety function of a system that is needed to mitigate the consequences of an accident described in USAR Chapters 6 and 15. This condition is reportable under 10 CFR 50.73(a)(2)(v)(C).
A change to the RT system procedure was implemented in 1989 to allow placing RT LO bypass switches into Bypass to prevent an unwanted or unwarranted isolation of the RT system during system manipulations. The associated safety evaluation went through several levels of management concurrence. Based on the reporting guidelines in place at the time, placing both divisions of RT LO in Bypass did not constitute a.reportable event. However, NUREG-1022, Rev.
3 indicates that a report is required when SSCs are inoperable in a required mode unless as part of a planned evolution for maintenance or surveillance testing when done in accordance with an approved procedure and the plant's TS.
C.
CAUSE OF EVENT
The apparent cause of the failure to report this event was the failure to perform plant procedure revisions when Exelon Generating Company (EGG) fleet reporting procedure requirements changed with the implementation of NUREG-1022, Revision 3. Plant procedure revisions did not occur because the change management process applied in this instance did not require an Operations cross-functional review when the EGC fleet reporting procedure was issued.
D.
SAFETY ANALYSIS
This event had no actual nuclear safety consequences.
RT recirculates a portion of reactor coolant through a filter demineralizer to remove particulate and dissolved impurities from the reactor coolant. It also removes excess cool?tnt from the reactor system under controlled conditions. RT is not required to function during or immediately following an accident and is isolated from post-accident fluids.
The purpose the RT LD System is to monitor RT components, activating a system isolation should a system leak of sufficient magnitude occur. Other operational controls remained available to monitor RT parameters, including temperature detection in the affected areas to allow isolation of the RT System.
E.
CORRECTIVE ACTIONS
A standing order was put into place to require reporting if both divisions of RT LD bypass switches are placed in Bypass unless if it is part of a planned evolution for maintenance or testing.
CPS Procedures 3303.01 and 5000.02, "Alarm Panel 5000 Annunciators -Row 2," have been revised to indicate that placing both RT leak detection system switches in the bypass position at the same time while in modes 1, 2 or 3 for reasons other than to support maintenance or testing is a reportable event per 10CFR50.72 and 10CFR50.73. An action was also created to review other Operations procedures to determine if a safety function is bypassed for reasons other than maintenance or testing.
F.
PREVIOUS SIMILAR OCCURENCES
No previous events were identified associated with the failure to report bypassing a safety function.
G.
COMPONENT FAILURE DATA
There were no component failures associated with this event.
PLANT AND SYSTEM IDENTIFICATION
I SEQUENTIAL I NUMBER 003 REV NO.
00 General Electric-Boiling Water Reactor, 3473 Megawatts Thermal Rated Core Power Energy Industry Identification System (EllS) codes are identified in the text as [XX]
EVENT IDENTIFICATION 2
Bypassing Both Divisions of Reactor Water Cleanup Leak Detection System is a Reportable Loss of Sat ety Function A.
Plant Operating Conditions before the Event
Event Date: 03/24/16 Event Time:
1157 OF Unit: 1 Mode: 1 Mode Name: Power Operation Reactor Power:
99 percent B.
DESCRIPTION OF EVENT
On March 24, 2016, it was determined that placing both Reactor Water Cleanup System (RT) Leak Detection System (LO) bypass switches in the Bypass position per Clinton Power Station (CPS)
Procedure 3301.01, "Reactor Water Cleanup" when the RT Filter/Demineralizer (F/D) was placed in service following backwash and pre-coat operations was a reportable condition. It was determined from the Operations Log for January 25, 2016 that both divisions of the RT LD were bypassed for seven minutes.
The fol.lowing Operations log entries document the actions taken on January 25, 2016:
0940: Placed 'A' RT F/D in Hold for backwash and pre-coat per procedure CPS 3303.01 section 8.1.3 and procedure CPS 3303.02, "Reactor Water Cleanup Filter Demineralizer Operating Procedure," sections 8.2 and 8.5.
1155:
Placed RT F/D 'B' in Hold.
1157: When pressurizing RT F/D 'A' received RT differential flow alarm. Placed both divisions of RT LD in Bypass, this will render both RWCU diffe.rential flow instruments INOPERABLE.
Verified Dose Equivalent Iodine 1-131 specific activity is< 1.8 x 10e-3 µCi/gm (actual 1.84 x 1 Oe-6 µCi/gm) per CPS 3303.01 step 6.9 and Technical Specification (TS) Limiting Condition for Operation (LCO) 3.3.6.1, "Primary Containment and Drywall Isolation Instrumentation." Entered the following action statements: - LCO 3.3.6.1, Required Action D.1 - Place channel in trip in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and LCO 3.3.6.1 Required Action E.1 -
Restore RT isolation capability in 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
2016 003 00 1159: Placed RT F/O 'B' on Service following backwash of 'A' F/O.
1202: Placed RT F/O 'A' on Service following backwash.
1204: Placed both divisions of RT LO bypass switches in Normal. Performed channel check SAT. Exit LCO 3.3.6.1 Required Action 0.1 and E.1 actions.
- 3. PAGE 3
OF An evaluation determined that placing both divisions of the RT LO switches in the Bypass position represented a loss of safety function that was not part of a planned evolution for maintenance or testing. Backwashing and pre-coating a RT F/O, as indicated in the Operations Log, is a normal system operation and not considered maintenance. Therefore, placing both divisions of RT LO switches in Bypass was reportable. The Updated Safety Analysis Report (USAR), the TS Bases, and NRG reporting requirements were reviewed as part of an evaluation regarding event
reportability
Based on this review, it was determined that the RT LO system is credited to mitigate a break in the RT system piping inside containment accident as described in USAR Chapter 6. As a result, it was concluded that placing both divisions of RT LO switches in Bypass as described in this LER, represented a condition that could have prevented the fulfillment of the safety function of a system that is needed to mitigate the consequences of an accident described in USAR Chapters 6 and 15. This condition is reportable under 10 CFR 50.73(a)(2)(v)(C).
A change to the RT system procedure was implemented in 1989 to allow placing RT LO bypass switches into Bypass to prevent an unwanted or unwarranted isolation of the RT system during system manipulations. The associated safety evaluation went through several levels of management concurrence. Based on the reporting guidelines in place at the time, placing both divisions of RT LO in Bypass did not constitute a.reportable event. However, NUREG-1022, Rev.
3 indicates that a report is required when SSCs are inoperable in a required mode unless as part of a planned evolution for maintenance or surveillance testing when done in accordance with an approved procedure and the plant's TS.
C.
CAUSE OF EVENT
The apparent cause of the failure to report this event was the failure to perform plant procedure revisions when Exelon Generating Company (EGG) fleet reporting procedure requirements changed with the implementation of NUREG-1022, Revision 3. Plant procedure revisions did not occur because the change management process applied in this instance did not require an Operations cross-functional review when the EGC fleet reporting procedure was issued.
D.
SAFETY ANALYSIS
This event had no actual nuclear safety consequences.
RT recirculates a portion of reactor coolant through a filter demineralizer to remove particulate and dissolved impurities from the reactor coolant. It also removes excess cool?tnt from the reactor system under controlled conditions. RT is not required to function during or immediately following an accident and is isolated from post-accident fluids.
The purpose the RT LD System is to monitor RT components, activating a system isolation should a system leak of sufficient magnitude occur. Other operational controls remained available to monitor RT parameters, including temperature detection in the affected areas to allow isolation of the RT System.
E.
CORRECTIVE ACTIONS
A standing order was put into place to require reporting if both divisions of RT LD bypass switches are placed in Bypass unless if it is part of a planned evolution for maintenance or testing.
CPS Procedures 3303.01 and 5000.02, "Alarm Panel 5000 Annunciators -Row 2," have been revised to indicate that placing both RT leak detection system switches in the bypass position at the same time while in modes 1, 2 or 3 for reasons other than to support maintenance or testing is a reportable event per 10CFR50.72 and 10CFR50.73. An action was also created to review other Operations procedures to determine if a safety function is bypassed for reasons other than maintenance or testing.
F.
PREVIOUS SIMILAR OCCURENCES
No previous events were identified associated with the failure to report bypassing a safety function.
G.
COMPONENT FAILURE DATA
There were no component failures associated with this event. 4