ONS-2013-035, Revision to Tornado/Helb Mitigation Strategies and Regulatory Commitments 8T, 10T, 17T, and 25H

Revision to Tornado/Helb Mitigation Strategies and Regulatory Commitments 8T, 10T, 17T, and 25H

ML13358A044
Person / Time
Site:	Oconee
Issue date:	12/19/2013
From:	Batson S Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
ONS-2013-035
Download: ML13358A044 (13)

Text

DU KE SCOTT L. BATSON Vice President ENERGY, Oconee Nuclear Station Duke Energy ONO I VP / 7800 Rochester Hwy Seneca, SC 29672 864-873-3274 ONS-2013-035 864-873-4208 fax Scott.Batson@duke-energy.com December 19, 2013 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Duke Energy Carolinas, LLC Oconee Nuclear Station, Units 1, 2, and 3 Docket Numbers 50-269, 50-270, and 50-287, Renewed Operating Licenses DPR-38, DPR-47, and DPR-55 Revision to Tornado/HELB Mitigation Strategies and Regulatory Commitments 8T, 10T, 17T, and 25H

References:

1. NRC Letter from Henry B. Barron (Duke Power Company, LLC), "Tornado/HELB Mitigation Strategies and Regulatory Commitments," dated November 30, 2006.

2. NRC letter from Scott L. Batson (Duke Energy Carolinas, LLC) "Revision to Tornado Mitigation Strategy Regulatory Commitments 1 1T, 12T, 13T, and 16T,"

dated July 1,2013.

3. NRC letter to Duke Energy Carolinas, LLC, "Notice of Violation and Confirmatory Order Related to a Fire Protection Program License Condition (Oconee Nuclear Station Units 1, 2, and 3)," dated July 1,2013.

This letter documents Duke Energy Carolinas, LLC (Duke Energy) notification to the Nuclear Regulatory Commission (NRC) of a revision to the tornado and High Energy Line Break (HELB) mitigation strategy commitments (Ref. 1). The Enclosure to this letter contains two (2) tables showing the complete list of tornado and HELB commitments made to the Staff and last revised on July 1, 2013 (Ref. 2).

The revised implementation schedule includes revisions to tornado commitments 8T and 17T. Commitment 8T is the completion of the Protected Service Water (PSW) system that was changed from July 1, 2013, to February 4, 2016, to coincide with the date given in a NRC Notice of Violation and Confirmatory Order (Ref. 3). Commitment 17T improves the protection of the Standby Shutdown Facility (SSF) double doors to comply with UFSAR SSF tornado criteria. Due to the lead time required to design and construct the new SSF tornado missile shield door and the unanticipated diversion of resources to work on emergent work, this commitment was changed to January 31, 2015.

Additionally, Commitments 1OT and 25H, which require that the NRC Deputy Director, Division of Reactor Licensing be notified of significant changes in the scope and/or completion dates of the commitments, were changed to coincide with the longest lead commitment item contained in the tables. These are ongoing commitments that will be in www.duke-energy.com

U. S. Nuclear Regulatory Commission December 19, 2013 Page 2 place until 2022. By phone, the basis for this change was discussed with the Staff on December 17, 2013.

Duke Energy remains committed to the completion of these projects and recognizes its contribution to resolution of outstanding tornado, HELB, and fire protection regulatory issues as well as its significant positive impact on the station's probabilistic risk assessment margin. As such, the project team's goal is to complete the PSW project as soon as reasonably achievable. In no case will safety or quality be compromised for the sake of schedule.

If you have any questions in regard to this letter, please contact Stephen C. Newman, Oconee Nuclear Station, Regulatory Affairs Group at (864) 873-4388.

Sincerely, Scott Batson Vice President, Oconee Nuclear Station Enclosure

U. S. Nuclear Regulatory Commission December 19, 2013 Page 3 cc (w/enclosure):

Mr. Victor McCree, Regional Administrator U. S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. Richard Guzman, Senior Project Manager (By electronic mail only)

U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation 11555 Rockville Pike Rockville, MD 20852 Mr. Eddy Crowe NRC Senior Resident Inspector Oconee Nuclear Site Ms. Susan Jenkins, Manager Radioactive & Infectious Waste Management Division of Waste Management South Carolina Department of Health and Environmental Control 2600 Bull St.

Columbia, SC 29201

Enclosure Revised Tornado and HELB Regulatory Commitments www.duke-energy.com

Enclosure - Revised Tornado and HELB Regulatory Commitments December 19, 2013 Page 1 Complete Tornado Commitments Due Date Cmlt No. (YIN) 1T U3 Control Room North Wall Modification. - Y 2T SSF Diesel Fuel Vent Modification. - Y 3T SSF and CT-5 Trenches Intersection Modification SSF - Y Trench at north end of SSF (TORMIS).

4T Borated Water Storage Tank Modifications. - Y 5T West Penetration Room (WPR) and Cask Decontamination - Y Tank Room (CDTR) Wall Modifications.

6T Fiber Reinforced Polymer (FRP) LAR for strengthening - Y selected masonry walls for tornado wind and AP.

7T Tornado Mitigation Strategy LAR. - Y 8T PSW/HPI modifications. 2-4-2016 N 9T Missile inventory program developed. Y 10T Verbally notify in advance the Deputy Director, Division of 2022 N Reactor Licensing of the NRC, followed by a written communication, of significant changes in the scope and/or completion dates of the commitments. The notification will include the reason for the changes and the modified commitments and/or schedule.

11T Installation of MSIVs. Ul: 2020 N 12T U2: 2021 13T U3:2022 14T Fiber Reinforced Polymer (FRP) LAR for strengthening Y selected "brick" masonry walls for tornado wind and AP.

15T Analyze the double column set which support each unit's Y Main Steam lines outside of the containment building, and provide modifications, as necessary, to meet tornado criteria 16T Physically protect the Atmospheric Dump Valve's (ADV's) UI: 2020 N function per RG 1.76, Rev. 1. U2: 2021 U3: 2022 17T Improve protection of the Standby Shutdown Facility (SSF) 1-31-2015 N double doors (large 8'x12' doors located on the south side of the SSF structure) per UFSAR SSF tornado criteria.

18T Revise and clarify the tornado LB description as After issuance of N documented in UFSAR Section 3.2.2; add the TORMIS the SER.

methodology results to UFSAR Section 3.5.1.3, and correct inaccurate tornado design information for the Auxiliary Building Cable and Electrical Equipment Rooms as described in UFSAR Table 3-23.

Enclosure - Revised Tornado and HELB Regulatory Commitments December 19, 2013 Page 2 No. Tornado Commitments 19T The SSF BASES for TS 3.10.1 will be clarified to address degradation of passive civil features as not applying to operability under Technical Specifications Limiting Condition for Operation (TS LCO) 3.10.1, "Standby Shutdown Facility," but rather as UFSAR commitments outside of the ONS TS.

20T1 Duke Energy will perform qualification testing and reporting in accordance with ICC AC1 25 [Reference 5 of Enclosure 2] for the selected FRP System.

21T Duke Energy will perform and document a technical evaluation of the FRP system (fibers and polymeric resin) in accordance with Duke Energy's Supply Chain Directive SCD230 [Reference 7 of Enclosure 2] to demonstrate that:

1. The item qualifies as a commercial grade item.

2. The supplier is capable of supplying a quality product.

3. The quality of the item can be reasonably assured.

22T Duke Energy will utilize technical procedures to control testing of concrete substrate and installation and inspection of the FRP system in accordance with ICC AC125

[Reference 5 of Enclosure 21, ACI 440.2R-02 [Reference 6 of Enclosure 2], and ICC AC1 78 [Reference 8 of Enclosure 2].

23T Duke Energy will perform long-term inspection of the FRP Y system as described in UFSAR Section 18.3.13 and EDM-410, and in accordance with ICC AC1 25 [Reference 5 of Enclosure 2], ACI 440.2R-02 [Reference 6 of Enclosure 2],

and ICC AC178 [Reference 8 of Enclosure 2], on a nominal 5 year interval. This inspection frequency may be reduced to a nominal 10 year interval with appropriate justification based on the structure, environment, and previous long-term inspection results. Inspections of the installed FRP system will include:

• visual inspections of test walls and selected portions of WPR walls for changes in color, debonding, peeling, blistering, cracking, crazing, deflections and other anomalies; and,

• tension adhesion testing of cored samples taken from test walls using methods specified in ASTM D4541

[Reference 9 of Enclosure 2] or ACI 530R-02

[Reference 16 of Enclosure 2].

24T 2 Duke Energy will perform qualification testing and reporting Y in accordance with ICC AC125 [Approved 10/2006, Effective 1/1/2007] for the selected FRP System.

1 Tornado commitments 20-23 originate from the FRP LAR dated 6-1-2006 (NRC SER dated 2-21-2008).

2 Tornado commitments 20-26 are addressed in the NRC's FRP SER for brick masonry dated 6-27-2011.

Enclosure - Revised Tornado and HELB Regulatory Commitments December 19, 2013 Page 3 Tornado Commitments Due Date Complete No.

(Y/N) 25T Duke Energy will perform and document a technical Y evaluation of the FRP system (fibers and polymeric resin) in accordance with Duke Energy's Supply Chain Directive SCD230 [Reference 7 of Enclosure 2] to demonstrate that:

• The item qualifies as a commercial grade item.

• The supplier is capable of supplying a quality product.

• The quality of the item can be reasonably assured.

26T Duke Energy will utilize technical procedures to control Y testing of concrete substrate and installation and inspection of the FRP system in accordance with ICC ACl 25

[Approved 10/2006, Effective 1/1/2007], ACI 440.2R-02

[Effective 7/1/2002], and ICC AC1 78 [Approved 6/2003, Effective 7/1/2003, editorially revised 6/2008].

Enclosure - Revised Tornado and HELB Regulatory Commitments December 19, 2013 Page 4 Tornado Commitments Due Date Complete No.

(Y/N) 27T Duke Energy will implement a long-term inspection Y program of the FRP system that will be described in UFSAR Section 18.3.13 and EDM-410, meet the requirements of ICC AC1 25 [Approved 10/2006, Effective 1/11/2007], ACI 440.2R-02 [Effective 7/1/2002], and ICC AC1 78 [Approved 6/2003, Effective 7/1/2003, editorially revised 6/2008], on the following schedule: at each unit's outage cycle for the first six years from 2012 through 2017, then, if justified based on no observed FRP degradation, transition to every-other outage cycle for the next four years from 2018 through 2021, then, ifjustified based on continued no observed FRP degradation, transition to every third outage cycle thereafter from 2022 until end of license in July 2034. Inspections of the installed FRP system will include:

• visual inspections of test walls and portions (both random and controlled locations) of WPR in-service walls for changes in color, debonding, peeling, blistering, cracking, crazing, deflections and other anomalies;

" tension adhesion testing of cored samples taken from designated test walls using methods specified in ASTM D7234; and,

• visual inspections of mortar joints located along the bottom edge of FRP-strengthened masonry walls.

For each inspection interval, the portions of FRP-strengthened masonry walls to be inspected will be chosen in accordance with a sampling plan developed from guidance provided by a) Draft Regulatory Guide DG-1 070, "Sampling Plans Used for Dedicating Simple Metallic Commercial Grade Items for use in Nuclear Power Plants",

and b) EPRI NP-7218 document "Guidelines for the Utilization of Sampling Plans for Commercial Grade Item Acceptance" (NCIG-19), as implemented at ONS by Supply Chain Directive SCD-290 [(new) Reference 21 of Enclosure 2].

Note: This response replaces the five (5) year inspection commitment made in FRP LAR (No. 2009-05) dated June 29, 2009, and will apply to the FRP application for both block and brick.

28T Duke Energy will install mechanical shear restraints along Y the brick masonry wall perimeter (top and sides only) and block masonry wall perimeter (top only) to remediate potentially limiting conditions of construction.

29T Duke Energy will incorporate the FRP testing and Y inspection program into Oconee Nuclear Station's Aging Management Program.

Enclosure - Revised Tornado and HELB Regulatory Commitments December 19, 2013 Page 5 Tornado Commitments Due Date Complete No.

(YIN) 30T As discussed with the Staff, Fyfe Company, LLC, the Y manufacturer of the FRP products, will provide Duke Energy with a Certificate of Compliance certifying that both the FRP product and its installation meet all applicable requirements.

HELB Commitments Due Date Complete No.

(YIN) 1H Implement an inspection program for the Aux Bldg MS and - Y FW girth and accessible attachment welds.

2H Implement an inspection program for other Aux. Bldg high - Y energy piping critical crack locations at welds.

3H Initial ASME Section Xl ISI interval UT of the Aux. Bldg MS - Y and FW girth welds and accessible attachment welds.

4H Initial ASME Section XI ISI interval UT of other Aux. Bldg - Y high energy piping critical crack locations at welds.

5H Implement an inspection program for accessible piping - Y base metal downstream of the FW isolation valves located in the EPR.

6H Implement an inspection program for accessible piping - Y base metal of other Aux. Bldg high energy piping critical crack locations not at welds.

7H Initial ASME Section Xl ISI interval UT inspection of piping - Y base metal downstream of FW isolation valves located in the EPR.

8H Initial ASME Section XI ISI interval UT inspection for Y accessible piping base metal of other Aux. Bldg high energy piping critical crack locations not at welds.

9H Implement an inspection program of accessible attachment - Y welds at the terminal ends inside the FW guard pipe.

10H Initial visual inspections of accessible attachment welds at - Y the terminal ends inside the FW guard pipe.

11H Inspect and repair the Unit 2 East Penetration Room Y electrical penetration termination enclosures to their correct configuration. Missing and/or damaged covers, gaskets, and fasteners will be repaired or replaced.

12H Inspect and repair the Unit 1 East Penetration Room Y electrical penetration termination enclosures to their correct configuration. Missing and/or damaged covers, gaskets, and fasteners will be repaired or replaced.

Enclosure - Revised Tornado and HELB Regulatory Commitments December 19, 2013 Page 6 Complete Tornado Commitments Due Date Cmlt No. (Y/N) 13H Inspect and repair the Unit 3 East Penetration Room Y electrical penetration termination enclosures to their correct configuration. Missing and/or damaged covers, gaskets, and fasteners will be repaired or replaced.

14H Create an inspection plan to select a portion of Units 1, 2 - Y and 3 enclosures to open and inspect for signs of internal debris and corrosion.

15H Revise station procedures and processes as needed to - Y ensure penetration termination enclosures are maintained in their correct configurations.

16H Complete the design and installation of flood outlet devices - Y for the Unit 1 East Penetration Room.

17H Complete the design and installation of flood outlet devices - Y for the Unit 2 East Penetration Room.

18H Complete the design and installation of flood outlet devices - Y for the Unit 3 East Penetration Room.

19H Complete the design and installation of flood impoundment - Y and exterior door flood improvement features for the Unit 1 East Penetration Room 20H Complete the design and installation of flood impoundment - Y and exterior door flood improvement features for the Unit 2 East Penetration Room.

21 H Complete the design and installation of flood impoundment - Y and exterior door flood improvement features for the Unit 3 East Penetration Room.

22H HELB LB and Mitigation Strategy LARs. Y 23H 24H 25H Verbally notify in advance the Deputy Director, Division of 2022 N Reactor Licensing of the NRC, followed by a written communication, of significant changes in the scope and/or completion dates of the commitments. The notification will include the reason for the changes and the modified commitments and/or schedule.

26H The inlet isolation valves to the Letdown Coolers on the To be provided to N Letdown Line (1 HP-1 & 1 HP-2) will be upgraded to permit the Staff upon their use following a postulated HELB on the Letdown Line issuance of the at Containment Penetration No. 6. With these valves SER.

upgraded, either could then be closed if either of the inboard containment isolation valves (1 HP-3 & 1HP-4) fails to close in order to mitigate the postulated HELB on the Letdown line.

Enclosure - Revised Tornado and HELB Regulatory Commitments December 19, 2013 Page 7 Complete (YIN)

No. Tornado Commitments Due Date (YIN) 27H The ducting near the Control Complex is being upgraded To be provided to N with duct registers or cover plates to prevent the potential the Staff upon propagation of the HELB generated environment in the issuance of the East Penetration Room to the Control Complex. SER.

28H The valves (1 HP-103 & 1HP-107) on the individual suction - Y lines to the "A" & "B" High Pressure Injection (HPI) pumps are being upgraded to allow the remote operation (operated outside the HPI pump room) of these valves.

The remote operation of these valves allow the isolation of postulated HELBs on the discharge side of the HPI Pumps without compromising the availability of the other HPI Pumps and the need for maintaining the Letdown Storage Tank aligned to the HPI Pump suction piping. For a single active failure of either valve 1HP-103 or 1HP-107 to close, a redundant, remotely operated valve is provided on each of the HPI Pumps "A" and "B" to assure HELB mitigation.

29H The position of several Plant Heating System isolation Y valves is being changed from "OPEN" to "CLOSED." This position change will eliminate the need to postulate Plant Heating System HELBs in the East Penetration Room and West Penetration Room, because these piping lines will isolated during normal plant conditions of the station.

30H Turbine Building structural support column D-26 will be To be provided to N modified by adding a brace to the column. This brace is the Staff upon necessary to prevent potential failure of the column, when issuance of the subjected to a pipe whip load. This upgrade prevents the SER.

loss of the routing to get temporary cabling to the Low Pressure Injection and Low Pressure Service Water pump motors.

31 H The existing Condenser Circulating Water (CCW) To be provided to N discharge stop gates will be replaced and four (4) new stop the Staff upon gates will be obtained. These stop gates will be used to issuance of the terminate all reverse flow through HELB damaged Low SER.

Pressure Service Water and CCW piping. This modification is required, in order to recover from a Turbine Building flood event caused by a postulated HELB therein.

32H Evaluate the ability of the Standby Shutdown Facility to Y perform its safety functions with a compromised main steam pressure boundary due to potential breaks in the main steam system and other HELBs.

33H Weep holes will be installed in the bottom of the outside- Y containment junction box enclosures for the Viking Electrical Penetrations. Also, the electrical penetration inspection procedure is being amended to inspect the weep holes for blockage

Enclosure - Revised Tornado and HELB Regulatory Commitments December 19, 2013 Page 8 Tornado Commitments Due Date Complete No.

(YIN) 34H The inlet isolation valves to the Letdown Coolers on the To be provided to N Letdown Line (2HP-1 & 2HP-2) will be upgraded to permit the Staff upon their use following a postulated HELB on the Letdown Line issuance of the at Containment Penetration No. 6. With these valves SER.

upgraded, either could then be closed if either of the inboard containment isolation valves (2HP-3 & 2HP-4) fails to close in order to mitigate the postulated HELB on the Letdown line.

35H The Unit 2 HVAC ducting near the Control Complex is To be provided to N being upgraded with duct registers or cover plates to the Staff upon prevent the potential propagation of the HELB generated issuance of the environment in the East Penetration Room to the Control SER.

Complex.

36H The valves (2HP-103 & 2HP-107) on the individual suction To be provided to N lines to the "A" & "B" High Pressure Injection (HPI) pumps the Staff upon are being upgraded to allow the remote operation issuance of the (operated outside the HPI pump room) of these valves. SER.

The remote operation of these valves allow the isolation of postulated HELBs on the discharge side of the HPI pumps without compromising the availability of the other HPI Pumps and the need for maintain the Letdown Storage Tank aligned to the HPI Pump suction piping. For a single active failure of either valves 2HP-1 03 or 2HP-1 07 to close, a redundant, remotely operated valves is provided on each of the HPI Pumps "A" and "B" to assure HELB mitigation.

37H The position of several Unit 2 Plant Heating System Y isolation valves is being changed from "OPEN" to "CLOSED." This position change will eliminate the need to postulate Plant Heating System HELBs in the East Penetration Room and West Penetration Room, because these piping lines will be isolated during normal plant conditions of the station.

38H Turbine Building structural support Column D-29 & D-31 To be provided to N will be modified by adding a brace to the column. This the Staff upon brace is necessary to prevent potential failure of the issuance of the column, when subjected to a pipe whip load. SER.

39H Weep holes will be installed in the bottom of the Unit 2 Y outside-containment junction box enclosures for the Viking Electrical Penetrations. Also, the electrical penetration inspection procedure is being amended to inspect the weep holes for blockage.

40H The inlet isolation valves to the Letdown Coolers on the To be provided to N Letdown Line (3HP-1 and 3HP-2) will be upgraded to the Staff upon permit their use following a postulated HELB on the issuance of the Letdown Line at Containment Penetration No. 6. With SER.

these valves upgraded, either could then be closed if either of the inboard containment isolation valves (3HP-3 and 3HP-4) fails to close in order to mitigate the postulated HELB on the Letdown Line.

Enclosure - Revised Tornado and HELB Regulatory Commitments December 19, 2013 Page 9 Complete (Y/N)

Tornado Commitments Due Date No. (YIN) 41 H The Unit 3 Auxiliary Building HVAC ducting near the Unit 3 To be provided to N Control Complex is being upgraded with duct registers or the Staff upon cover plates to prevent the potential propagation of the issuance of the HELB generated environment in the East Penetration SER.

Room to the Unit 3 Control Complex.

42H The valves (3HP-103 and 3HP-107) on the individual Y suction lines to the "A" and "B" High Pressure Injection (HPI) pumps are being upgraded to allow the remote operation (operated outside the HPI pump room) of these valves. The remote operation of these valves allow the isolation of postulated HELBs on the discharge side of the HPI Pumps without compromising the availability of the other HPI Pumps and the need for maintaining the Letdown Storage Tank aligned to the HPI Pump suction piping. For a single active failure of either valve 3HP-103 or 3HP-107 to close, a redundant, remotely operated valve is provided on each of the HPI Pumps "A" and "B" to assure HELB mitigation.

43H The position of the Unit 3 Plant Heating System isolation Y valve 3AS-182 being changed from "OPEN" to "CLOSED."

This position change will eliminate the need to postulate Plant Heating System HELBs in the East Penetration Room and West Penetration Room, because these piping lines will be isolated during Normal Plant Conditions of the station.

44H Turbine Building structural support columns M-20 (Unit 1), To be provided to N M-35 (Unit 2), D-43 and D-45 (Unit 3), M-49 (Unit 3), and L- the Staff upon 47 (Unit 3) will be modified by adding a brace or issuance of the reinforcement to each column. These modifications are SER.

necessary to prevent potential failure of the column(s),

when subjected to a pipe whip load.

45H Weep holes will be installed in the bottom of the Unit 3 Y outside-containment junction box enclosures for the Viking Electrical Penetrations. Also, the electrical penetration inspection procedure is being amended to inspect the weep holes for blockage.