05000390/LER-2016-007, Regarding Technical Specification Action Not Met for Rod Position Indication
| ML16172A022 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 06/20/2016 |
| From: | Simmons P Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 16-007-00 | |
| Download: ML16172A022 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3902016007R00 - NRC Website | |
text
Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381 June 20,2016 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001
Subject:
10 cFR 50.73 Watts Bar Nuclear Plant, Unit 1 Facility Operating License No. NPF-90 NRC Docket No.50-390 Licensee Event Report 390/2016-007-00, Technical Specification Action Not Met for Rod Position !ndication This submittal provides Licensee Event Report (LER) 390/2016-007-00. This LER provides details concerning a failure to enter Technical Specification 3.1.8. This report is being submitted in accordance with 10 CFR 50.73(a)(2)(i)(B).
Please direct any questions concerning this matter to Gordon Arent, WBN Licensing Director, at (423) 365-2004.
Enclosure cc: see Page 2 aul Silsffons Site Vice President Watts Bar Nuclear PIa
U.S. Nuclear Regulatory Commission Page 2 June 20,2016 cc (Enclosure):
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Watts Bar Nuclear Plant
. NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (1 1-2015)
"'"t
- o'?.
rtbe
'"'ffi-LI.ENSEE EVENT REP.RT (LER)
, *ra.,
APPROVED BY OMB: NO. 3{50-0104 EXPIRES: 1013112018 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 />.
Reprted lessons learned are incorporated into the licensing process and fed back to indusfy.
Send comments regarding burden estimate to the FOIA, Privacy and lnformation Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 2055$0001, or by intemet e-mail to lnfocollects.Resource@nrc.gov, and to the Desk fficer, ffice of lnformation and Regulatory Affairs, NE0B-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. lf a means used to impose an inbrmation collection does not display a cunently valid OMB conhol number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 1. FACILITY NAME Watts Bar Nuclear Plant, Unit 1
- 2. DOCKET NUMBER 05000390
- 3. PAGE 10F5
- 4. TITLE Technical Specification Action Not Met for Rod Position lndication
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTHI DAY I YEAR YEAR I t=-t'r=JJSt REV NO.
MONTH I DAY YEAR FACTLTTY NAME I
DOCKET NUMBER N/A I
N/A 11 I 05 12015 2016 r007
- - 00 06 20 2016 FACTLTTY NAME I
DOCKET NUMBER N/A I
N/A
- 9. OPERATING MODE I l. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR $z (Check atl that apply) 1 tr 20.2201(b) tr 2o.22os(aX3Xi) tr 50.73(aX2XiiXA) tr 50.73(aX2XviiiXA) tr 2o.zzot(d) n zo.22o3(aX3)(ii) tr 50.73(aX2)(iiXB) tr 50.73(aX2Xviii)(B) tr 20.2203(a)(1) tr 20.2203(aX4) tr 50.73(ax2xiii) tr 50.73(aX2Xix)(A) tr 2o.z2o3(aX2)(i) tr 50.36(cX1)(iXA) tr 50.73(aX2XivXA) tr s0.73(ax2xx)
- 10. POWER LEVEL 100 tr 2o.z2os(aX2Xi.)
tr 50.36(cX1)(iiXA) n 50.73(aX2XvXA) tr n.t1(aX4) tr 2o.2zo3(aX2Xiii) tr 50.36(cX2) tl s0.73(a)(2XvXB) tr rc.71(aXs) tr 20.2203(aX2Xiv) tr 50.46(ax3xii) tr s0.73(aX2XvXc) tr B.rt(a)(1\\
tr 2o.2zo3(aX2Xv) tr 50.73(aX2)(i)(A) tr s0.73(aX2XvXD) n fi.rt(a)(2xi) tr 2o.z2o3(aX2Xvi)
X 50.73(a)(2X.XB) tr s0.73(aX2Xvii) tl B.t7(aX2Xii) tr 50.73(aX2X.Xc) tr OTHER Specify in Abstract below or in
F. Method of discovery of each Component or System Failure or Procedural Error
While there was a dropped rod event, the WBN licensing position that a dropped rod (inoperable rod) in accordance with TS 3.1.5 did not require entry into TS 3.1.8 has been determined to be incorrect.
G. Failure Mode and Effect of Each Failed Component Shutdown Bank A Rod D2 dropped into the reactor core. While there was a dropped rod event, it was not the cause of personnel failing to comply with the requirements of TS 3.1.8.
H. Operator Actions
ln response to the dropped rod, operators took actions to reduced reactor thermal power to comply with TS 3.1.5 and3.2.4.
l. Automatically and Manually Initiated Safety System Responses
There were no automatic or manual safety system responses associated with this event.
III. CAUSE OF THE EVENT
A. The cause of each component or system failure or personnel error, if known.
The dropped rod occurred as a result of an electrical ground caused by moisture intrusion from a reactor coolant system leak. The leak was found during a subsequent maintenance outage on a Control Rod Drive Mechanism (CRDM) threaded vent plug which had decreased torque. A sealwelded vent plug was installed to prevent further leakage.
While there was a dropped rod event, this issue was the result of an incorrect licensing position (CR 979285) addressing how to comply with TS 3.1.8, specifically, whether TS LCO 3.1.8 for Rod Position lndication (RPl) should be entered after a dropped rod as a result of not being able to successfully perform the associated 18-month TS SR 3.1.8.1.
B. The cause(s) and circumstances for each human performance related root cause.
The cause of this event was an incorrect licensing position of how to comply with TS 3.1.8.
IV. ANALYSIS OF THE EVENT
On November 05, 2015, WBN Unit t had a dropped rod event and entered TS 3.1.5, Rod Group Alignment Limits, Condition B; however, TS 3.1.8, Rod Position lndication, was notentered as required. The Surveillance Requirement for TS 3. 1.8 states that each ARPI agrees within 12 steps of the group demand position for the full indicated range of rod travel. Since the ARPI was indicating correctly for the dropped rod and was verified by diverse indications, operations staff considered the APRI operable. However, the TS Bases for TS 3.1.8 states that for the position indication to be operable, the Rod Position lndication System indicates within 12 steps of the step counter demand position as required by TS 3.1.5. ln the case of a dropped control rod, the rod position for the affected rod would not be within 12 steps of the demand
counter. Since Unit 1 at the time of the dropped rod was in a mode of applicability, the above conditions would not have been met warranting entry into TS 3.1.8 Condition A.
WBN licensing position that a dropped rod (inoperable rod) in accordance with TS 3.1.5 did not require entry into TS 3.1.8 has been determined to be incorrect. Through various discussions with personnel, both internal and external to TVA, WBN confirmed that Condition A of TS 3.1.8 should have been entered. The TS LCO was not met based on the inability to meet TS SR in TS 3.1.8 and the LCO 3.1.8 bases description stating, in part, that ARPI meet TS LCO 3.1.5 makes this TS applicable for this condition.
A Late entry was made in the Narrative Log for the time period TS 3.1.8 was not met.
V. ASSESSMENT OF SAFEW CONSEQUENCES A. Availability of systems or components that could have performed the same function as the components and systems that failed during the event.
There were no safety system failures associated during this event.
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 CR 1163150.
A. lmmediate Corrective Actions A late entry was made in the Narrative Log for the time period TS 3.1.8 was not met.
B. Corrective Actions to Prevent Recurrence WBN provided a communication to Operations on May 11, 2016 stating that in the event of a dropped controlrod TS LCO 3.1.5 and 3.1.8 are to be entered.
The industry has developed a revision to the Standard TechnicalSpecifications, NUREG-1431to decouple entry into TS 3.1.8 when TS 3.1.5 is required. WBN plans to adopt Technical Specifications Task Force (TSTF) Traveler TSTF 547 to address the TS revision.
VII. ADDITIONAL INFORMAT]ON A. Previous similar events at the same plant LER 2016-002, Technical Specification Action Not Met for lnoperable Containment lsolation Valve, describes a similar event of personnel failing to comply with the requirements of Technical Specifications. ln this LER, WBN Unit 1 entered TS 3.6.3, Containment lsolation Valves, for a containment isolation valve being inoperable. The requirement to isolate the penetration associated with this containment isolation valve was not completed within TS time requirements. The cause of this event was operations staff misunderstanding the applicability of the Note associated with TS 3.6.3, which allows administrative controls under certain conditions. ln response to this event, a shift order defining the correct response when entering TS 3.6.3 Condition A was provided to the operating staff, and is to be a topic of future operations training. The response to this issue was specific to TS 3.6.3 and would not have prevented this event.
No other control rod drop events in the last ten years were identified at WBN Unit 1.
B. Additional lnformation None.
C. Safety System Functional Failure Consideration This condition did not result in a safety system functionalfailure.
D. Scrams with Complications Consideration There was no scram associated with this report.
VIII. COMMITMENTS
None.Paoe 5 of 5