ML13297A492
| ML13297A492 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 10/24/2013 |
| From: | Kennedy K NRC/RGN-IV/DRP |
| To: | Matthew Sunseri Wolf Creek |
| References | |
| NOED 13-4-003, TAC MF2925 | |
| Download: ML13297A492 (4) | |
Text
UNITE D S TATE S NUC LEAR RE GULATOR Y C OMMI S SI ON R E G IO N I V 1600 EAST LAMAR BLVD AR L I NGTON , TEXAS 7 601 1- 4511 October 24, 2013 Matthew W. Sunseri, President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839
SUBJECT:
NOTICE OF ENFORCEMENT DISCRETION FOR WOLF CREEK NUCLEAR OPERATING CORPORATION (TAC NO. MF2925, NOED NO. 13-4-003)
Dear Mr. Sunseri:
By letter dated October 22, 2013, (ML13296A137), the Wolf Creek Nuclear Operating Corporation (WCNOC), requested that the U.S. Nuclear Regulatory Commission exercise discretion to not enforce compliance with the actions required in multiple Wolf Creek Generating Station (WCGS) Technical Specifications (TS) related to declaring the Train A Class 1E electrical equipment air conditioning unit SGK05A non-functional. This letter documented information previously discussed with the NRC in a telephone conference on October 18, 2013, at 8:00 p.m. (all time references below will be in Central Daylight Time). The principal NRC staff members who participated in the telephone conference included Kriss Kennedy, Director, Division of Reactor Projects, Region IV; Tom Blount, Director, Division of Reactor Safety, RIV; Jeff Clark, Deputy Director, Division of Reactor Safety, RIV; Louise Lund, Deputy Director, Division of Operating Reactor Licensing, Office of Nuclear Reactor Regulation; Neil OKeefe, Chief, Project Branch B, RIV; Fred Lyon and Balwant Singal, Project Managers, Plant Licensing Branch 4, NRR; Sheldon Stuchell, Notice of Enforcement Discretion (NOED) Process Coordinator, NRR; Singh Matharu, Electrical Engineering Branch, NRR; Gerald Waig, Technical Specification Branch, NRR; David Loveless, Senior Reactor Analyst, RIV; Charles Peabody, Senior Resident Inspector, RIV; Raja Stroble, Resident Inspector, RIV; and Jeff Circle, Senior Reliability and Risk Analyst, PRA Operational Support Branch, NRR.
On October 18, 2013, at 11:41 a.m., the licensee declared the Train A Class 1E electrical equipment air conditioning unit SGK05A non-functional when they determined that air conditioning unit SGK05A was not capable of performing its specified function for its full mission time. This unit was tripping on a low lube oil pressure signal from a faulty pressure sensor. All other pressure indications showed normal oil pressure, and electrical measurements revealed a faulty output from the sensor in question. Two Train A inverters, the Train A AC and DC distribution systems, and the Train A batteries and battery chargers supported by the non-functional Train A Class 1E air conditioning unit, were declared inoperable. As a result, the licensee entered the Required Actions of the associated Conditions of:
- TS 3.8.7, "Inverters - Operating,"
- TS 3.8.9, Distribution Systems - Operating.
M. Sunseri The Required Actions of the associated Conditions to be entered for TSs 3.8.4 and 3.8.9 permit a period of time to restore inoperable equipment to operable status before a shutdown is required. However, the Required Actions of the associated Conditions for TS 3.8.7 do not specify a condition for two inoperable inverters in one train. In accordance with limiting condition for operation (LCO) 3.0.3, when an LCO is not met or an associated action is not provided, action shall be initiated within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> to place the unit, as applicable, in Mode 3 within 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />; Mode 4 within 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br />; and Mode 5 within 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br />. At 11:41 a.m., a plant shutdown was initiated in accordance with LCO 3.0.3. The licensee completed the plant shutdown and entered Mode 3 at 5:35 p.m., in compliance with the TSs.
During the teleconference, the licensee requested that the NRC exercise enforcement discretion to avoid an unnecessary plant transient and to permit noncompliance with LCO 3.0.3, TS 3.8.4, TS 3.8.7, and TS 3.8.9. The licensee requested 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> from the time of entry into LCO 3.0.3 at 11:41 a.m. on October 18, 2013, to restore air conditioning unit SGK05A to functional status and complete testing. This NOED would allow the licensee to remain in Mode 3 to perform repairs, rather than cool down to Mode 4, and subsequently, Mode 5. The incremental conditional core damage probability (ICCDP) and incremental conditional large early release probability (ICLERP) were quantified for the requested additional time for restoring air conditioning unit SGK05A without crediting risk reduction for related compensatory actions. The results of the licensees quantification were compared to the guidance thresholds in Inspection Manual Chapter 0410, Notices of Enforcement Discretion, (ML13071A487). The licensee also stated that there was no net increase in radiological risk to the public.
The licensee implemented compensatory risk management measures prior to making the request for enforcement discretion, which were to remain in effect throughout the proposed period of discretion. The compensatory measures included installing a temporary cooling unit to cool the spaces normally cooled by air conditioning unit SGK05A, with a second temporary unit available as backup in case of failure of the running temporary unit; monitoring room temperatures every two hours; and implementing a fire watch to compensate for fire barriers that would be breached by the temporary cooling unit. The licensee also stated that no severe weather was forecast which could challenge offsite power availability during the proposed period of enforcement discretion, and grid conditions were normal, and no maintenance would be performed on safety-related equipment.
The licensee stated that the proposed change did not involve a significant hazard consideration based on the three standards set forth in 10 CFR 50.92(c), and did not involve adverse consequences to the environment such that the proposed change meets the categorical exclusion set forth in 10 CFR 51.22(c)(9). The WCGS Plant Safety Review Committee approved the NOED request on October 18, 2013, prior to the verbal request for an NOED.
Because the request was a one-time extension of the required completion times for repairs, the licensee stated that a follow-up license amendment request was not required.
The NRC used the Standardized Plant Analysis Risk (SPAR) Model version 8.20 for WCGS and hand calculations to independently assess risk for the conditions proposed during the period of enforcement discretion being requested. During the call, the NRC staff was unable to reconcile differences between the staffs risk assessment and the risk assessment presented by the licensee. In particular, the staffs assessment indicated that without crediting a reduction in risk from the proposed compensatory measures, the value for ICCDP would exceed the threshold for ICCDP discussed in Inspection Manual Chapter 0410 (5 E-7). In the event of a loss of offsite power, the proposed compensatory room cooling would be lost to Train A and could not be recovered prior to offsite power restoration. The licensee was unable to provide information
M. Sunseri regarding the room heat-up rate or time to failure of the Train A equipment for this scenario, so the staff was not able to further evaluate risk reduction credit. Also, the licensee was using a recently updated probabilistic risk assessment model, while the staff was using the current SPAR model that did not include the changes. The staff was unable to determine, in the limited time available, if crediting the licensees changes for this specific evaluation was appropriate.
Based on the staffs independent risk assessment and the inability to reconcile differences with the licensees risk assessment, the NRC staff could not conclude that the requested discretion would not exceed the level of risk determined acceptable during normal work controls. As a result, the request for enforcement discretion was denied at 11:10 p.m. on October 18, 2013.
The staff informed the licensee that compliance with the TS was required based on the original time the systems were declared inoperable.
In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter will be made available electronically for public inspection in the NRC Public Document Room or from the NRC's document system (ADAMS), accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html.
Should you have any questions concerning this letter, please contact Neil OKeefe, Chief, Project Branch B, at (817) 200-1141.
Sincerely,
/RA/
Kriss M. Kennedy, Director Division of Reactor Projects Docket No: 50-482 License No: NPF-42 50-313 Cc: Electronic Distribution
M. Sunseri Electronic distribution by RIV:
Acting Regional Administrator (Steven.Reynolds@nrc.gov)
Acting Deputy Regional Administrator (Thomas.Bergman@nrc.gov)
DRP Director (Kriss.Kennedy@nrc.gov)
DRP Deputy Director, (Troy.Pruett@nrc.gov)
DRS Director (Tom.Blount@nrc.gov)
DRS Deputy Director (Jeff.Clark@nrc.gov)
Senior Resident Inspector (Charles.Peabody@nrc.gov)
Resident Inspector (Raja.Stroble@nrc.gov)
WC Administrative Assistant (Carey.Spoon@nrc.gov)
Branch Chief, DRP/B (Neil.OKeefe@nrc.gov)
Senior Project Engineer, DRP/B (David.Proulx@nrc.gov)
Project Engineer, DRP/B (Megan.Williams@nrc.gov Public Affairs Officer (Victor.Dricks@nrc.gov)
Public Affairs Officer (Lara.Uselding@nrc.gov)
Project Manager (Fred.Lyon@nrc.gov)
Branch Chief, DRS/TSB (Ray.Kellar@nrc.gov)
Branch Chief, ACES (Heather.Gepford@nrc.gov)
Senior Enforcement Specialist, ACES (Rachel.Browder@nrc.gov)
RITS Coordinator (Marisa.Herrera@nrc.gov)
Regional Counsel (Karla.Fuller@nrc.gov)
Congressional Affairs Officer (Jenny.Weil@nrc.gov)
OEMail Resource NOED Resource (NOED.Resource@nrc.gov)
OE Web Resource (OEWEB.Resource@nrc.gov)
RIV/ETA: OEDO (Daniel.Rich@nrc.gov)
NRR DORL Director (Michele.Evans@nrc.gov)
Director, Office of Enforcement (Roy.Zimmerman@nrc.gov)
NRR/DORL/Plant Licensing Branch IV Chief (Michael.Markley@nrc.gov)
NRR/DORL Deputy Director (Louise.Lund@nrc.gov)
File located: S:\DRP\DRPDIR\_WC ADAMS: No Yes SUNSI Review Complete Reviewer Initials: NFO Publicly Available Non-Sensitive
. Non-publicly Available Sensitive C:RIV/DRP/B D:RIV/DRS D:NRR/DORL D:RIV/DRP NOKeefe TBlount MEvans KKennedy
/RA DProulx for/ /RA JClark for/ /RA via Email/ /RA/
10/23/13 10/23/13 10/24/13 10/24/13 OFFICIAL RECORD COPY T=Telephone E=E-mail F=Fax