05000390/LER-2017-002, Regarding: Incorrectly Hung Clearance Leads to a Condition Prohibited by the Technical Specifications
| ML17053A884 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 02/22/2017 |
| From: | Simmons P Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 17-002-00 | |
| Download: ML17053A884 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2) |
| 3902017002R00 - NRC Website | |
text
Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381 Febru ary 22, 2017 10 cFR 50 73 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 1 Facility Operating License No. NPF-90 NRC Docket No. 50-390 Subject: Licensee Event Report 39012017-002-00, lncorrectly Hung Glearance Leads to a Condition Prohibited by the Technical Specifications This submittal provides Licensee Event Report (LER) 39012017-002-00. This LER provides details concerning an error made while hanging a clearance which led to a condition prohibited by the Technical Specifications. This report is being submitted in accordance with 10 CFR 50.73(a)(2)(iXB).
There are no regulatory commitments contained in this letter. Please direct any questions concerning this matter to Gordon Arent, WBN Licensing Director, at (423) 365-2004.
pectfqll AL. A.\\
Jt Site Vice President Watts Bar Nuclear Plant Enclosure cc: See Pag e 2
U,S. Nuclear Regulatory Commission Page 2 Febru ary 22, 2A17 cc (Enclosure):
NRC Regional Administrator - Region ll NRC Senior Resident lnspector - Watts Bar Nuclear Plant
NRC FORM 366 U.S. NUCLEAR REGULATORY COMN'IESION (06-2C16)
LICENSEE EVENT REPORT (LER}
APPROVED BY OMB: NO. 3150-0{04 EXPIRES: 10/31/20{8 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 cornrnenb regarding burden estimate to the FOIA, Privacy and lnformation Coilections Branch {T-5 F53), U,$, Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to lnfocoilects.Resource@nrc.gov, and to the Desk 0fficer, Cffice of lnformation and Reguiaiory Affairc, NE0B-142CI2, (3150-0104), 0fiice of Management and Budget, Washington, DC 20503. lf a means used to impose an information collection does not display a currently valid OMS conti'ol number, the NRC may not conduct 0r sponsor, and a person is not required to respond to, the information coilection.
- 1. FACILITY NAME Watts Bar Nuclear Plant. Unit 1
- 2. DOCKET NUMBER 05000390
- 3. PAGE 1
of 5
- 4. TITLE lncorrectly Hung Clearance Leads to a Condition Prohibited by the Technical Specifications
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTHI DAY I YEAR YEAR I 'i,l!ff#L REV NO.
MONTH I DAY YEAR FACILITY NAME I
oocxET NUMBER None I
12 24 I 2016 2017 -002
- - 00 a2 22 2017 FACILlTY NAME I
DOCKET NUITJBER
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I.
PLANT OPERATING CONDITIONS BEFORE THE EVENT
Watts Bar Nuclear Plant (WBN) Unit 1 was at 100 percent rated thermal power (RTP).
II.
DESCRIPTION OF EVENT
A. Event Summary On December 24,2016, Watts Bar Nuclear Plant (WBN) personnel identified that a clearance associated with a containment purge valve, 1-FCV-30-17 {EllS:FCV}, had been incorrectly hung.
The clearance was intended to pull fuses associated with valve 1-FCV-30-17, resulting in the valve being closed and de-energized. The incorrect fuses were removed, and valve 1-FCV-30-17 remained energized while local leak rate testing (LLRT) was performed on the associated containment purge system {EllS:BB} penetration. This has been determined to be a condition prohibited by Technical Specification 3.6.3, Limiting Condition for Operation (LCO), Condition A, because the penetration was inoperable for longer than the four hour required action time.
This event is being reported to the Nuclear Regulatory Commission (NRC) under 10 CFR 50.73(aX2)(i)(B) as a condition prohibited by Technical Specifications (TS).
B. lnoperable Structures, Components, or Systems that Contributed to the Event No inoperable systems beyond the identified valve contributed to this report.
C. Dates and Approximate Times of Occurrences
Date Time Event (EST) 12123116 1400 Operations commences 1-Sl-30-701, Containment lsolation Valve Local Leak Rate Test Purge Air 12124116 1345 Operations exits compliance with TS LCO 3.6.3 Condition A associated with 1-Sl-30-701.
12124116 1701 Condition Report 1245529 written related to discovery of clearance error.
D. Manufacturer and Model Number of Components that Failed During the Event There were no failed components associated with this event.
E. Other Systems or Secondary Functions Affected
No other systems or secondary functions were affected.
F. Method of discovery of each Component or System Failure or Procedural Error
The clearance error was discovered during the clearance restoration process.
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G. Failure Mode and Effect of Each Failed Component Not applicable.
H. Operator Actions
When the clearance error was discovered, a condition report was generated and an investigation was performed.
l. Automatically and Manually lnitiated Safety System Responses There were no safety system responses associated with this issue.
III. CAUSE OF THE EVENT
A. The cause of each component or system failure or personnel error, if known.
The cause of the clearance error was a personnel error in positively identifying the correct fuses to be removed.
B. The cause(s) and circumstances for each human performance related root cause.
The cause of the clearance error was a personnel error in positively identifying the correct fuses to be removed. The clearance placement first and second checkers performed a concurrent verification on the wrong component due to an inadequate component verification. The issues that occurred were due to difficulties presented in the location of the labels in the battery board and the verification tools used to adequately read and see the labels.
IV. ANALYSIS OF THE EVENT
WBN personnel were in the process of performing LLRT on containment purge valves in accordance with plant procedure 1-Sl-30-701, Containment lsolation Valve Local Leak Rate Test Purge Air. Penetration 10B consists of an air operated, fail-closed valve inside containment (1-FCV-30-17) and a similar air operated fail-closed valve outside containment (1-FCV-30-16). A test valve between the two ClVs is provided outside containment. To reduce the dose associated with performing this testing on-line, each test connection on each purge penetration is run to a common test manifold. Each test valve is leak tested for the purge penetrations. Then all of the test valves associated with the containment purge penetrations are opened, and each penetration is individually leak tested. With the test valves open, the purge penetrations become inoperable and must be isolated by a closed deactivated valve. With the fuses not pulled for valve 1-FCV-30-17, this purge valve was closed, but not deactivated. This configuration is not in accordance with plant procedures. The test valve associated with penetration 10B was likely open for greater than four hours but less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
It is noted that the tested penetration met acceptance criteria, in that 1-FCV-30-17 was capable of performing its containment isolation function during the surveillance. When testing was completed, the TS 3.6.3 actions were satisfied based on acceptable leakage and final operability was maintained. The Page 3 of 5,
operability review also determined that the pulling of the incorrect fuses did not cause additional inoperability.
V, ASSESSMENT OF SAFETY CONSEQUENCES The subject valve, 1-FCV-30-17, was closed with danger tags on the hand switch but not deactivated.
While this is inconsistent with the TS, there is no identified single failure that could have resulted in the valve opening or creating a containment bypass. Therefofe, while this is a condition prohibited by TS, the safety implications are low.
A. Availability of systems or components that could have performed the same function as the components and systems that failed during the event The subject valve was closed with danger tags hung on the operating switch. There is no single active failure that could have caused the valve to open or create a containment bypass.
B. For events that occurred when the reactor was shut down, availability of systems or components needed to shutdown the reactor and maintain safe shutdown conditions, remove residual heat, control the release of radioactive material, or mitigate the consequences of an accident Not applicable.
C. For failure that rendered a train of a safety system inoperable, an estimate of the elapsed time from the discovery of the failure until the train was returned to service Not applicable.
VI. CORRECTIVE ACTIONS
This event was entered into the Tennessee Valley Authority (TVA) Corrective Action Program and is being tracked under condition report (CR) 1245529.
A. lmmediate Corrective Actions When the condition was identified, a CR was initiated and an investigation performed.
B. Corrective Actions to Prevent Recurrence or to Reduce Probability of Similar Events Occurring in the Future Additional training related to the performance of concurrent verification will be performed with all operating crews.
VII, PREVIOUS SIMILAR EVENTS AT THE SAME SITE LER 390/2016-009-00 describes a condition prohibited by TS 3.6.3 where the requirements to isolate a containment penetration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> was not met. The event described in this LER is different in that the correct actions to comply with the TS were understood, but a human performance error resulted in the correct actions not being performed.
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LER 390/2016-002-00 describes d condition where by misinterpreting the requirements of TS 3.6.3, the containment penetration was not isolated within four hours. The event described in this LER is different in that the correct actions to comply with the TS were understood, but a human performance error resulted in the correct actions not being performed.
VIII, ADDITIONAL INFORMATION None.
IX
COMMITMENTS
None.
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