05000390/LER-1917-015, Regarding Failure to Enter Limiting Condition of Operation Action Statement Results in a Condition Prohibited by Technical Specifications
| ML18008A215 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 01/08/2018 |
| From: | Simmons P Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 17-015-00 | |
| Download: ML18008A215 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 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)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) |
| 3901917015R00 - NRC Website | |
text
Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381 January 8, 2017 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Units 1 and 2 Facility Operating License Nos. NPF-90 and NPF-96 NRC Docket Nos. 50-390 and 50-391 10 CFR 50.73
Subject:
Licensee Event Report 390/2017-015-00, Failure to Enter Limiting Condition of Operation Action Statement Results in a Condition Prohibited by Technical Specifications This submittal provides Licensee Event Report (LER) 390/2017-015-00. This LER provides details concerning inappropriate use of guidance leading to a condition prohibited by Technical Specifications, and is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B).
A supplement to this report addressing cause and corrective actions is expected to be submitted by March 8, 2018.
There are no regulatory commitments contained in this letter. Please direct any questions concerning this matter to Kim Hulvey, WBN Licensing Manager, at (423) 365-7720.
Respectfully, Paul Simmons Site Vice President Watts Bar Nuclear Plant Enclosure cc: See Page 2
U.S. Nuclear Regulatory Commission Page 2 January 8, 2018 cc (Enclosure):
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Watts Bar Nuclear Plant
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 0313112020 (04-2017)
, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Watts Bar Nuclear Plant, Unit 1 05000390 1 OF 5
- 4. TITLE Failure to Enter Limiting Condition of Operation Action Statement Results in a Condition Prohibited by Technical Specifications
- 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 Watts Bar Nuclear Plant, Unit 2 05000391 FACILITY NAME DOCKET NUMBER 11 09 2017 2017 - 015 00 1
08 2018
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
D 20.2201 (b)
D 20.2203(a)(3)(i)
D 50.73(a)(2)(ii)(A)
D 50.73(a)(2)(viii)(A) 1 D 20.2201 (d)
D 20.2203(a)(3)(ii)
D 50.73(a)(2)(ii)(B)
D 50.73(a)(2)(viii)(B)
D 20.2203(a)(1)
D 20.2203(a)(4)
D so.73(a)(2)(iii)
D 50.73(a)(2)(ix)(A)
D 20.2203(a)(2)(i)
D 50.36(c)(1)(i)(A)
D 50.73(a)(2)(iv)(A)
D 50.73(a)(2)(x)
- 10. POWER LEVEL D 20.2203(a)(2)(ii)
D 50.36(c)(1)(ii)(A)
D 50.73(a)(2)(v)(A)
D 73.71(a)(4)
D 20.2203(a)(2)(iii)
D so.3s(c)(2)
D 50.73(a)(2)(v)(B)
D 73. 71 <a)(5)
D 20.2203(a)(2)(iv)
D so.4s(a)(3)(ii)
D 50.73(a)(2)(v)(C)
D 73.77(a)(1) 100 D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
D 50.73(a)(2)(v)(D)
D 73.77(a)(2)(i)
D 20.2203(a)(2)(vi)
~ 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 73.77(a)(2)(ii)
D 50.73(a)(2)(i)(C)
D OTHER Specify in Abstract below or in 2017 015 00 The issue was identified by an NRC resident inspector.
G. Failure Mode and Effect of Each Failed Component There was no equipment failure associated with this event.
H. Operator Actions
Upon identification of the issue, non-TS ESF coolers were not removed from service without either entering a TS LCO Action Statement or having an engineering evaluation performed to demonstrate that with the cooler removed from service and a failure of the opposite train (including associated train coolers}, no loss of safety function would occur if an accident were to occur and thereby not necessitating a TS LCO Action Statement entry.
I.
Automatically and Manually Initiated Safety System Responses
None.
Ill.
CAUSE OF THE EVENT
A.
The cause of each component or system failure or personnel error, if known.
The cause of this issue is under investigation.
B. The cause(s) and circumstances for each human performance related root cause.
The cause of this issue is under investigation.
IV.
ANALYSIS OF THE EVENT
NRC Generic Letter 80-30 identifies requirements related to the operability of plant equipment including support systems. The definition of operability includes "cooling" which would be inferred to mean ventilation and heat exchangers. A specific subset of Watts Bar equipment to which the above statement applies would be the non-TS ESF area coolers In 2002, the Perry nuclear plant was issued a clarification letter for the intended treatment of an "unusual" support system arrangement in which a non-TS support system has two redundant 100% capacity subsystems, each capable of supporting both trains of TS equipment. In this letter, it was clarified that the loss of one support subsystem does not result in a loss of support for either train of TS equipment, and both TS trains would remain operable despite a loss of support function redundancy, because the TS definition of operability does not require a TS subsystem's necessary support function to meet the single failure design criterion. The risk of operating in a non-single failure proof configuration could be assessed and managed by 10 CFR 50.65(a)(4), i.e., the Maintenance Rule. This guidance was defined in its own cover letter as a "clarification of existing generic guidance developed by the TS Section of the Office of Nuclear Reactor Regulation," and appeared to be generic in intent and application. The Perry guidance was adopted by WBN in 2010.
2017 015 00 NRC position on this issue may have changed and is documented in a number of violations at other stations starting in the late 2000's and 2010 time period. These issues were identified and are the source of CR 1357258.
V.
ASSESSMENT OF SAFETY CONSEQUENCES
Engineering evaluations pertaining to the safety consequences of this issue are in progress; however, at this time, a number of auxiliary building areas have been evaluated assuming one cooler out of service, coincident with an accident and single failure resulting in the loss of the opposite train of ESF equipment (including coolers). These preliminary reviews have demonstrated that the safety function for the equipment served by the applicable coolers would have been met, and the need to enter TS LCOs as supporting equipment was not required.
A Availability of systems or components that could have performed the same function as the components and systems that failed during the event The impact of this issue is under investigation.
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 The impact of this issue is under investigation.
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 The impact of this issue is under investigation.
VI.
CORRECTIVE ACTIONS
This event was entered into the Tennessee Valley Authority (TVA) Corrective Action Program and is being tracked under Condition Report (CR) 1357258.
A
Immediate Corrective Actions
Upon identification of the issue, Non-TS ESF area coolers were not removed from service without either entering a TS LCO or having an evaluation performed to demonstrate that with the cooler removed from service and a failure of the opposite train (including associated train coolers), no loss of safety function would occur.
B. Corrective Actions to Prevent Recurrence or to Reduce Probability of Similar Events Occurring in the Future Actions to prevent recurrence will be provided in a supplement to this report.
VII.
PREVIOUS SIMILAR EVENTS AT THE SAME SITE
This will be provided in a supplement to this report.
VIII.
ADDITIONAL INFORMATION
None.
IX.
COMMITMENTS
None. YEAR 2017 SEQUENTIAL NUMBER 015 REV NO.
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