ML13154A014
| ML13154A014 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee  |
| Issue date: | 05/29/2013 |
| From: | Stafford J Dominion Energy Kewaunee, Dominion |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML13154A014 (8) | |
Text
Dominion Energy Kewaunec, Inc.
N490 Hwy 42, Kewaunee, WI 54216 m in o Web Address: www.dom.com ATTN: Document Control Desk MAY 29 2013 Serial No.13-326 U. S. Nuclear Regulatory Commission LIC/MJH/RO Washington, DC 20555-0001 Docket No.: 50-305 License No.: DPR-43 DOMINION ENERGY KEWAUNEE. INC.
KEWAUNEE POWER STATION
SUMMARY
OF FACILITY CHANGES, TESTS AND EXPERIMENTS AND
SUMMARY
OF COMMITMENT CHANGES Pursuant to 10 CFR 50.59(d)(2), enclosed is a summary description of Facility Changes, Tests and Experiments evaluated in accordance with 10 CFR 50.59(c) and implemented at the Kewaunee Power Station (KPS) during the last reporting period, which is defined as not to exceed 24 months.
A commitment change evaluation summary for those commitment changes that occurred during the last reporting period is also enclosed.
The enclosed summary encompasses all changes that occurred in both of the stated areas since our prior submittal dated May 29, 2012 (reference 1).
If you have any questions or require additional, information, please feel free to contact Ms. Mary Jo Haese at 920-388-8277.
Very truly yours, Jeffrey T. Stafford Director Safety and Licensing Kewaunee Power Station 1LZ:e~M-
Serial No.13-326 Page 2 of 2 Commitments made by this letter: NONE
Reference:
- 1. Letter from Jeffery T. Stafford (Dominion Energy Kewaunee, Inc.) to Document Control Desk (NRC), "Summary of Facility Changes, Tests and Experiments and Summary of Commitment Changes," dated May 29, 2012.
cc: Regional Administrator, Region III U. S. Nuclear Regulatory Commission 2443 Warrenville Road Suite 210 Lisle, IL 60532-4352 Mr. K. D. Feintuch Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop O8-D15 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Kewaunee Power Station
Serial No.13-326 ATTACHMENT 1
SUMMARY
OF FACILITY CHANGES, TESTS AND EXPERIMENTS AND
SUMMARY
OF COMMITMENT CHANGES KEWAUNEE POWER STATION DOMINION ENERGY KEWAUNEE, INC.
Serial No.13-326 Attachment 1 Page 1 of 5 10 CFR 50.59 Evaluations 50.59 Evaluation # 12-03-00 Activity Evaluated Updated Safety Analysis Report (USAR) Revision for Sections 9.6.2.2 and 10.2.2.8 Brief Description 10 CFR 50.59 Evaluation # 12-03-00 was performed in support of USAR Change Request KPS-UCR-2011-018 to update an original licensing basis discussion regarding the potential for a lake barge to cover the circulating water intake structure and the resultant impact on the ultimate heat sink. This change was deemed necessary due to the presence of larger sized barges that now operate on the Great Lakes.
Reason for Chanqe USAR Change Request KPS-UCR-2011-018 was performed to revise the discussion in USAR Sections 9.6.2.2 and 10.2.2.8 regarding the potential for a lake barge to block the circulating water inlet structures. The original Safety Analysis Report (SAR) wording indicated that the inlet structures were spaced such that a lake barge could not block all water inlets and the complete functional loss of the main intake lines is extremely unlikely. The original licensing basis also credits the 30 inch recirculation line that interconnects the circulating water discharge structure to the screenhouse forebay as an alternate flow path to provide safety related service water cooling to meet the requirements of Safety Guide 27. In 2009, an editorial USAR change altered the statements regarding the likelihood of the inlets becoming blocked by a lake barge.
KPS-UCR-2011-018 was prepared to return some of the original SAR wording and to update the lake barge blockage discussion.
A 50.59 Screening was performed for the USAR change package and it was determined that due to the larger size barges in production today operating on the Great Lakes, barges of sufficient size exist that could block all of the main and auxiliary circulating water intake lines, if perfectly oriented over the intake structures. This activity to revise the USAR was determined to have an adverse effect on the design function to provide an ultimate heat sink.
A 10 CFR 50.59 Evaluation was performed in support of the USAR revision and concluded that a License Amendment was not required. The Evaluation considered that barges that operate on the Great Lakes have the potential, based on their size, to block all of the circulating water intake and auxiliary intake structures should an impaired barge drift off its course, perfectly orienting itself and sinking over the multiple intake structures. It was concluded there was no change in the likelihood of a larger barge to become perfectly oriented as there was for a smaller barge to reach the same ideal location.
The 50.59 Evaluation concluded that the existence of larger lake barges on the Great Lakes does not result in more than a minimal increase in the likelihood of occurrence of a malfunction of a structure/system/component (SSC) important to safety than previously evaluated in the USAR. The complete loss of circulating water is not an accident or an accident initiator. The frequency of occurrence of an accident and consequences of an accident remain unchanged.
Serial No.13-326 Attachment 1 Page 2 of 5 Summary 10 CFR 50.59 Evaluation # 12-03-00 was performed in support of USAR Change Request KPS-UCR-2011-018 that addressed an original licensing basis discussion regarding the potential for a lake barge to cover the intake structure resulting in complete blockage of all inlets and a complete loss of function of the circulating water intake structure, one of two flow paths supplying cooling water from the ultimate heat sink. The 50.59 Evaluation concluded that the existence of larger lake barges on the Great Lakes does not result in more than a minimal increase in the likelihood of occurrence of a malfunction of an SSC important to safety than previously evaluated in the USAR and does not impact any analyzed accident.
Commitment Change Evaluation Summary Document(s) Evaluated:
- 1. Letter from E.R. Mathews (WPSC) KPS Response, IEB 80-24, Prevention of Damage Due to Water Leakage Inside Containment (October 17, 1980 Indian Point 2 Event), dated January 8, 1981 (NRC-81-003)
- 2. Letter from P.D. Ziemer (WPSC) KNPP Response to Notice of Violation and Proposed Imposition of Civily Penatly, dated May 11, 1983 (NRC-83-106)
- 3. Letter from D.C. Hintz (WPSC) Generic Letter 88-05 Boric Acid Corrosion of Carbon Steel Reactor Pressure Boundary Components In PWR Plants, dated June 3, 1988, (NRC 88-77)
- 4. Letter from C.R. Steinhardt (WPSC) KNPP Response to Request for Additional Information - Generic Letter 95-07, dated July 18, 1995 (NRC-96-107)
- 5. Letter from E.J. Weinkam (NMC) NMC 90-Day Response to Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors, dated March 7, 2005 (NRC-05-030).
Brief
Description:
KPS committed to a monthly (which was changed to quarterly per the commitment change process) at-power containment inspection in reference 1, and took credit for the inspection in references 2, 3, 4, and 5. The decision was made to rescind this at-power containment inspection, due to various other containment inspections that occur cyclically, or as warranted by specific conditions. This change has three key issues of concern. They are detection of containment flooding, detection of boric acid corrosion, and detection of containment sump clogging.
Containment Flooding Rescinding the quarterly at-power containment inspection has no affect on the probability of flooding occurring because it concerns conditions after the flooding has already occurred. By crediting the functionality of the containment sump A indication and verifying the functionality at least monthly of the sump pumps, there is assurance that a flooding event would be identified promptly. Changing the inspection frequency of the at-power inspection from quarterly to under specific conditions does not significantly increase the consequences of unrecognized flooding in containment.
Boric Acid Corrosion Rescinding the quarterly at-power containment inspection does not affect those components susceptible to boric acid corrosion; it may change how quickly leakage of water containing boric acid is detected. The NRC has issued generic letters, bulletins, and information notices concerning instances of boric acid corrosion that affected plant
Serial No.13-326 Attachment 1 Page 3 of 5 equipment. Where warranted, inspection of specific components is included as a part of the in-service inspection program. This inspection is also performed during startups, prior to entering MODE 4 and prior to entering MODE 2, and under certain conditions when at-power. In addition, an inspection is performed when shutting the plant down in MODE 3 to find leakage to be repaired during the shutdown. Changing the inspection frequency of the at-power inspection from quarterly to under specific conditions does not significantly increase the probability or consequences of an accident previously evaluated.
Sump, Clogging Rescinding the quarterly at-power containment inspection will not affect sump clogging events at KPS. KPS' containment sump B is used during the recirculation phase of a Loss of Coolant Accident (LOCA) to ensure suction for the Emergency Core Cooling System (ECCS) pumps after the water from the refueling water storage tank has been injected. The containment sump strainers must be able to filter debris that may have been washed from the containment to the containment basement and allow water to pass to continue the cooling process. The containment sump strainers are not an accident initiator and have no affect on the probability of a LOCA. The strainer not being able to filter debris or allow water to pass may affect the consequences of the accident.
The ability to filter debris from the containment water is checked prior to exceeding 200'F (MODE 4) and prior to criticality (MODE 2). Once the plant is at-power, access to containment is restricted. Entrance into containment at-power to perform work in the area of the strainers will require an inspection of the strainers for damage. Similarly, inspections are performed prior to entering MODE 4 and MODE 2 to identify and remove unnecessary material from containment that would hinder the strainer's ability to pass water to cool the reactor core.
Scope:
Rescind the commitment for quarterly at-power containment inspections.
Basis for Change:
This change is to modify the conditions under which an at-power containment inspection is performed. This change will not alter the design function or operation of the structure/system/component (SSC) involved, nor will it affect the SSCs operation or its ability to perform its design function. The inspection is not an initiator of any accident therefore no new accidents are created.
Summary:
The commitment to perform a quarterly at-power containment inspection will be removed due to various other containment inspections that occur as previously described in the Brief Description above.
Serial No.13-326 Attachment 1 Page 4 of 5 Commitment Change Evaluation Summary Document(s) Evaluated:
- 1. Letter from C.R. Steinhardt (WPSC) Closeout to NRC Bulletin No. 88-04: Potential Safety-Related Pump Loss, dated November 8, 1994 (NRC-94-113)
Brief
Description:
In a series of correspondence between KPS and the NRC, it was determined that the minimum recirculation flow for the safety injection (SI) pumps at KPS was adequate. However, KPS committed to performing disassembled inspections of the SI pumps every 15 years to ensure no damage is occurring as a result of operation on mini-flow recirculation.
Scope:
Discontinue performance of disassembled inspections of the SI pumps every 15 years to ensure no damage is occurring as a result of operation on mini-flow recirculation.
Basis for Change:
In 1981 both pumps were inspected by a Sulzer Bingham technical representative who determined that, after over 7 years of operation, there was no evidence of cavitation or damage to the impellers due to mini-flow operation.
The 1A SI pump rotating element was installed in 1981. The 1A pump was inspected in May 1993 and the rotating assembly was re-installed. The 1A pump was again inspected in March 2011 and the rotating assembly was re-installed. From the March 6, 2011 entry of the Sulzer Pumps Field Report is the following statement: "Lifted the element from inner case and it look(s) like it had just been installed."
The rotating element in the 1 B SI pump was installed May 1995 because of a thrust bearing failure that damaged the rotating element. At that time the damaged rotating element was inspected (after 14 years of operation) and no evidence of damage due to minimum flow recirculation was found. The present rotating element has 17 years of operating time as of 2012.
The SI pumps are operated once each refueling cycle for full flow testing by procedures during which full pump flow is measured (and recorded) and vibration data is gathered. There have been no noteworthy changes in the pump operating characteristics.
SI pumps are operated quarterly for surveillance testing by procedures during which minimum pump recirculation flow is measured and recorded, and vibration data is gathered. There have been no noteworthy changes in the pump operating characteristics.
There has been no degradation to bearings detected that could be attributed to operation at low flow rates. Routine oil sampling and analysis is performed on both pumps and would have detected bearing wear particles if bearing degradation were occurring.
In a letter dated December 6, 1988, Sulzer Bingham indicated that the anticipated consequence of operation at low flow rates would be "hydraulic instability and possible cavitation or recirculation damage to the impellers."
Serial No.13-326 Attachment 1 Page 5 of 5 The 1A SI pump rotating element has 30 years of operation and "the element ... look(s) like it had just been installed." The 1 B SI pump has 14 years of operation and no degradation was observed. Vibration levels are trended and show no indication of an adverse trend. There are no observed ill effects due to internal recirculation and minimum flow, as expressed in NRC Bulletin 88-04, Potential Safety Related Pump Loss.
Summary:
Based on review of the maintenance and operational history of the Sl pumps, a record has been established that routine pump disassembly, to detect internal degradation resulting from low flow rates when operated on minimum flow recirculation, is not required. The previous commitments regarding NRC Bulletin 88-04, Potential Safety-Related Pump Loss, disassembled inspections of the SI pumps will no longer be performed for the purpose of detecting internal degradation resulting from low flow rates when operated on minimum flow recirculation.
Commitment Change Evaluation Summary Document(s) Evaluated:
- 1. Letter from C.R. Steinhardt (WPSC) Response to Industry Position on Severe Accident Management, dated January 30, 1995 (NRC-95-13)
- 2. Letter from C.R. Steinhardt (WPSC) Severe Accident Management, dated May 27, 1997 (NRC-97-50)
- 3. Letter from M.L. Marchi (WPSC) Severe Accident Management, dated June 25, 1998 (NRC-99-62)
Brief
Description:
In a letter to the NRC dated January 30, 1995, Wisconsin Public Service Corporation committed to implement the formal industry position on Severe Accident Management (SAM) at the Kewaunee Nuclear Power Plant.
Scope:
SAM will no longer be implemented at KPS.
Basis for Change:
SAM was developed based on severe accident considerations due to reactor core damage.
KPS has permanently removed all fuel from the reactor vessel, therefore there is no possibility of core damage occurring, and SAM is no longer relevant at KPS.
Summary:
SAM was developed based on severe accident considerations due to reactor core damage. By NRC submittals dated November 2, 2012 and February 25, 2013; KPS notified the NRC of its intention to permanently cease power operations. On May 14, 2013, DEK submitted a certification of permanent removal of fuel from the reactor vessel pursuant to 10 CFR 50.82(a)(1)(ii). Upon docketing of this certification, the 10 CFR Part 50 license for KPS no longer authorizes operation of the reactor or emplacement or retention of fuel into the reactor vessel, as specified in 10 CFR 50.82(a)(2). Therefore, SAM no longer applies to KPS.