Text

Updated Supplemental Response to NRC Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors.
	ML082380244
Person / Time
Site:	Turkey Point
Issue date:	08/11/2008
From:	Jefferson W; Florida Power & Light Co
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	GL-04-002, L-2008-160
	Download: ML082380244 (86)
	v • d • e

0 FPL.

POWERING TODAY.

AUG 11 2008 EMPOWERING TOMORROW.

L-2008-160 10 CFR 50.54(f)

U. S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, Maryland 20852 Florida Power & Light Company Turkey Point Unit 4 Docket No. 50-251

Subject:

Updated Supplemental Response to NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors"

References:

(1) Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors," dated September 13, 2004 (ML042360586)

(2) Letter L-2005-034 from J. A. Stall (FPL) to U. S. Nuclear Regulatory Commission "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors," dated March 4, 2005 (ML050670429)

(3) Letter from E. A. Brown (U. S. Nuclear Regulatory Commission) to J. A.

Stall (FPL), "Turkey Point Plant, Units 3 and 4 - Request for Additional Information (RAI) Related to Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors," dated June 2, 2005 (ML051520202)

(4) Letter L-2005-145 from J. A. Stall (FPL) to U. S. Nuclear Regulatory Commission "Request for Additional Information - Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors," dated July 20, 2005 (ML052080038)

(5) Letter L-2005-181 from J. A. Stall (FPL) to U. S. Nuclear Regulatory Commission "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors - Second Response," dated September 1, 2005 (ML052490339)

(6) Letter L-2006-028 from J. A. Stall (FPL) to U. S. Nuclear Regulatory Commission "Supplement to Response to NRC Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors," dated January 27, 2006 (ML060310245) 40 an FPL Group company

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Page 2 of 5 (7) Letter from B. T. Moroney (U. S. Nuclear Regulatory Commission) to J. A.

Stall (FPL) "Turkey Point, Units 3 and 4 , Request for Additional Information Re: Response to Generic letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design-Basis Accidents at Pressurized-Water Reactors," dated February 8, 2006 (ML060370438)

(8) Letter from C. T. Haney (U. S. Nuclear Regulatory Commission) to Holders of Operating Licensees for Pressurized Water Reactors, "Alternate Approach for Responding to the Nuclear Regulatory Commission Request for Additional Information RE: Generic Letter 2004-02," dated March 28, 2006 (ML060860257)

(9) Letter from B. T. Moroney (U. S. Nuclear Regulatory Commission) to J. A.

Stall (FPL) "Turkey Point Plant, Unit No. 4 - Approval of GSI-191/GL 2004-02 Extension Request," dated April 13, 2006 (ML060950574)

(10) Letter from C. T. Haney (U. S. Nuclear Regulatory Commission) to Holders of Operating Licenses for Pressurized Water Reactors, "Alternate Approach for Responding to the Nuclear Regulatory Commission Request for Additional Information Letter Regarding Generic Letter 2004-02," dated January 4, 2007 (ML063460258)

(11) Letter from W. H. Ruland (U. S. Nuclear Regulatory Commission) to A.

Pietrangelo (Nuclear Energy Institute), "Content Guide for Generic Letter 2004-02 Supplemental Responses," dated August 15, 2007 (ML071060091)

(12) Letter from W. H. Ruland (U. S. Nuclear Regulatory Commission) to A.

Pietrangelo (Nuclear Energy Institute), "Revised Content Guide for Generic Letter 2004-02 Supplemental Responses," dated November 21, 2007 (ML073110389)

(13) Letter from W. H. Ruland (U. S. Nuclear Regulatory Commission) to A.

Pietrangelo (Nuclear Energy Institute), "Supplemental Licensee Responses to Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors," dated November 30, 2007 (ML073320176)

(14) Letter from J. A. Stall (FPL) to U. S. Nuclear Regulatory Commission "Request for Extension of Completion Date of the St. Lucie Unit 1, St. Lucie Unit 2 and Turkey Point Unit 3 Generic Letter 2004-02 Actions," dated December 7, 2007 (ML073450338)

(15) Letter L-2008-033 from W. Jefferson, Jr., (FPL) to U. S. Nuclear Regulatory Commission "Supplemental Response to NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors," dated February 28, 2008 (ML080710429)

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Page 3 of 5 (16) Letter from J. A. Stall (FPL) to U. S. Nuclear Regulatory Commission "NRC Generic Letter 2004-02, Request for an Extension to the Completion Date for Ex-vessel Downstream Effects Evaluations," dated April 14, 2008 (ML081070252)

(17) Letter from B. Mozarari (U. S. Nuclear Regulatory Commission) to J. A.

Stall (FPL) "Turkey Point Nuclear Plant, Unit 4 - Approval of Extension Request for Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors," dated April 29, 2008 (ML081200606)

The purpose of this submittal is to provide the Florida Power and Light Company (FPL) updated supplemental response to Generic Letter (GL) 2004-02 (Reference 1) for Turkey Point Plant, Unit 4. The U. S. Nuclear Regulatory Commission (NRC) issued Reference 1 to request that addressees perform an evaluation of the emergency core cooling system (ECCS) and containment spray system (CSS) recirculation functions in light of the information provided in the GL and, if appropriate, take additional actions to ensure system functions.

Additionally, the GL requested addressees to provide the NRC with a written response in accordance with 10 CFR 50.54(f). The request was based on identified potential susceptibility of the pressurized water reactor (PWR) recirculation sump screens to debris blockage during design basis accidents requiring recirculation operation of ECCS or CSS and on the potential for additional adverse effects due to debris blockage of flowpaths necessary for ECCS and CSS recirculation and containment drainage.

Reference 2 provided the initial Florida Power and Light Company (FPL) response to the GL.

Reference 3 requested additional information regarding the Reference 2 response to the GL for Turkey Point Plant Units 3 and 4. Reference 4 provided the FPL response to Reference 3.

Reference 5 provided the second of two responses requested by the GL. In Reference 6, FPL requested an extension, until the Turkey Point Unit 4 spring 2008 refueling outage to complete the correction actions required by the GL. Reference 7 requested FPL to provide additional information to support the NRC staff's review of Reference 2, as supplemented by References 4 and 5.

Reference 8 provided an alternative approach and timetable that licensees may use to address outstanding requests for additional information (i.e., Reference 7). Reference 9 provided NRC approval of the Turkey Point Unit 4 extension, as requested by FPL in Reference 6. Reference 10 supplemented Reference 8 with the NRC expectation that all GL 2004-02 responses will be provided no later than December 31, 2007. For those licensees granted extensions to allow installation of certain equipment in spring 2008, the NRC staff expects that the facility response will be appropriately updated with any substantive GL corrective action analytical results or technical detail changes within 90 days of the change or outage completion. As further described in Reference 10, the NRC expects that all licensees will inform the NRC, either in supplemental GL 2004-02 responses or by separate correspondence as appropriate, when all GSI-191 actions are complete.

Reference 11 describes the content to be provided in a licensee's final GL 2004-02 response that the NRC staff believes would be sufficient to support closure of the GL. Reference 12 revised the guidance provided in Reference 11 by incorporating minor changes which were viewed by the NRC as clarifications.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Page 4 of 5 Reference 13 authorized all PWR licensees up to two months beyond December 31, 2007 (i.e.,

to February 29, 2008) to provide the supplemental responses to the NRC.

In Reference 14, FPL provided a chemical effects testing and assessment schedule and indicated that a Turkey Point Unit 4 updated supplemental response would be submitted within 3 months following the spring 2008 outage.

In Reference 15, FPL provided a Turkey Point Nuclear Plant supplemental response to GL 2004-02 using the content guide provided in Reference 11.

In Reference 16, FPL requested an extension until June 30, 2008, for completing ex-vessel downstream effects evaluations that support high head safety injection pump acceptance, for Turkey Point Unit 4. Approval of the extension request was granted by the NRC in Reference 17.

This letter provides an updated supplemental response, as discussed in References 14, 15, 16 and 17, using the NRC Revised Content Guide for GL 2004-02 Supplemental Responses, dated November 21, 2007, that was provided by the NRC in Reference 12. provides a summary level description of the approach taken to provide reasonable assurance that long-term core cooling is maintained, as requested by the revised content guide. provides the updated supplemental response to GL 2004-02 for Turkey Point Unit

4. Information previously provided, in Reference 15, continues to apply except where supplemented or revised. A revision bar in the right hand margin of the updated supplemental response indicates where information has been either supplemented or revised.

This letter also serves to inform the NRC that all GL 2004-02 related GSI-191 actions for Turkey Point Unit 4 are complete, as requested in Reference 10.

There are no new regulatory commitments made by FPL in this submittal.

This information is being provided in accordance with 10 CFR 50.54(f).

Please contact Olga Hanek, at (305) 246-6607, if you have any questions regarding this response.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on August 1/, 2008.

Sincerely yours, William erson,.

Site Vice President Turkey Point Nuclear Plant Attachments: (2)

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Page 5 of 5 cc: NRC Regional Administrator, Region II USNRC Project Manager, Turkey Point Nuclear Plant Senior Resident Inspector, USNRC, Turkey Point Nuclear Plant

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 1 Page 1 of 3 ATTACHMENT 1 Turkey Point Unit 4 GL 2004-02 Summary Description of Approach

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 1 Page 2 of 3

SUMMARY

DESCRIPTION OF APPROACH The following key aspects summarize the FPL approach to GL 2004-02 at Turkey Point Unit 4.

Design Modifications

New sump strainers ensure adequate NPSH during recirculation with margin for chemical effects

Replacement mechanical seals and the removal of the cyclone separators ensure long-term operation of the containment spray pumps

Removal of the PRT insulation and replacement of the RCP insulation with RMI ensures that strainer design basis fiber debris loads will not be exceeded Process Changes

The coating specification update ensures that strainer design basis coating debris loads will not be exceeded

The insulation specification has been revised to enhance configuration management controls to ensure that insulation within that could become debris does not exceed strainer design inputs.

Procedures are in place to ensure that the single potential choke point, refueling canal drain covers, are removed prior to Mode 4 restart so that the design basis sump water supply is available Supporting Analyses

Downstream effects evaluations confirm that no other modifications are required to ensure long-term cooling capability is maintained.

The combination of these design modifications, process changes, and supporting analysis provides reasonable assurance that long-term core cooling is maintained.

Conservatisms and Margin FPL has made improvements in the ECCS system to address the issues identified in Generic Letter 2004-02. As part of the analysis, FPL has included a number of conservatisms to ensure sufficient margin is available. These margins are summarized below.

The new sump strainer system installed in Turkey Point Unit 4 in the spring of 2008 is a Performance Contracting, Inc., design with a surface area of approximately 3,600 ft2 with 3/32-inch perforations to retain debris. The new strainers replaced the previous sump screens which had a combined total surface area of approximately 63 ft2 with a 1/4-inch screen mesh.

Debris interceptors have been installed at the exit points at the bioshield wall. These debris interceptors have been demonstrated to hold a significant amount of debris from a large break LOCA inside the biowall.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 1 Page 3 of 3

In the debris generation analysis, the ZOI used for Nukon insulation is 17D for piping and 7D for the steam generators. WCAP-16170-P testing confirmed that the zone of influence could be reduced further to 5D. As such, the strainer system was qualified utilizing a quantity of fiber that is significantly greater than is expected to be generated.

A uniform factor of 1.1 has been applied to the ZOI radius to ensure the calculation was conservative.

100% of unqualified coatings in the active pool, regardless of types and location inside containment, were assumed to fail as particulates and transport to the screen. EPRI and industry testing indicates some unqualified coatings do not fail and some coatings fail as chips and may not transport to the sump.

Scaling for the head loss testing was based on a strainer area of 3513.8 ft 2 (3613.8 - 100).

100 ft 2 was subtracted from the total strainer area to account for miscellaneous debris such as tags and labels even though testing indicated that these items will not transport to the screen.

In determining the velocity profile for testing, the computational fluid dynamics (CFD) analysis calculated the average velocities by "double weighting" the fastest velocity at the increment under consideration. Weighting the average by twice the fastest velocity incorporates conservatism into the calculation.

The amount of chemicals calculated to form in 30 days were added to the test flume, and as such, a 30 day chemical effect was applied in the early stages of the event. This is conservative as corrosion and formation of chemical precipitants is a time based phenomena and significant additional NPSH margin is available as the containment pool temperature decreases over time.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 1 of 78 ATTACHMENT 2 Turkey Point Unit 4 GL 2004-02 Updated Supplemental Response

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 2 of 78 UPDATED SUPPLEMENTAL RESPONSE TO GL 2004-02 This final supplemental response to NRC Generic Letter (GL) 2004-02 updates the information previously submitted in FPL letter L-2008-033, Supplemental Response to NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors," dated February 28, 2008. Changes to the original supplemental response are indicated by revision bars. Where the original text was relocated to meet the format requirements of the NRC staff's November 2007 guidance document, but otherwise unchanged, the text is shown as boxed text.

Additional information to support the Staff's evaluation of Turkey Point Unit 4 compliance with the regulatory requirements of GL 2004-02 was requested by the NRC in a "Request for Additional Information" (RAI) dated February 8, 2006 (NRC Letter to FPL (J. A. Stall), Turkey Point Plant, Units 3 and 4, Request for Additional Information RE: Response to Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized-Water Reactors" (TAC Nos. MC4725 and MC4726), February 8, 2006). Each RAI question is addressed in this response. The RAI response is identified by the RAI question number in the following format: [RAI ##], where ## is the RAI question number.

Topic 1: Overall Compliance FPL Response In letter L-2006-028 dated January 27, 2006, Florida Power & Light Company (FPL) requested a short extension to the completion schedule to extend the completion of corrective actions required by Generic Letter 2004-02 for Turkey Point Unit 4 until the spring 2008 outage. In the extension letter request, FPL committed to implement a number of compensatory hardware changes in the fall 2006 refueling outage. The extension request was approved by the NRC in a letter dated April 13, 2006, and the interim compensatory hardware changes were implemented as scheduled.

Turkey Point Unit 4 received construction permits prior to issuance of the proposed Appendix A to 10 CFR 50 and therefore the current licensing bases include aspects of the 1967 proposed criteria. Although numbered and worded somewhat differently, the 1967 proposed GDC have equivalent versions of the criteria that address the same concepts as the 10 CFR 50, Appendix AGDC.

Based on the completion of corrective actions and enhanced procedural controls, Table 1 provides the information which demonstrates that Turkey Point Unit 4 is in compliance with the regulatory requirements listed in the Applicable Regulatory section of GL 2004-02.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 3 of 78 Table 1: GL 2004-02 Regulatory Compliance Regulatory Applicable Requirement Basis For Compliance Statute 10 CFR 50.46 Long-term cooling. After any calculated successful

New sump strainers ensure (b)(5) initial operation of the ECCS, the calculated core adequate NPSH during recirculation temperature shall be maintained at an acceptably low with margin for chemical effects value and decay heat shall be removed for the

Replacement mechanical seals and extended period of time required by the long-lived the removal of the cyclone radioactivity remaining in the core. separators ensure long-term operation of the containment spray pumps

Removal of the PRT insulation and replacement of the. RCP insulation with RMI ensures that strainer design basis fiber debris loads will not be exceeded

The coating specification update ensures that strainer design basis coating debris loads will not be exceeded

The insulation specification has been revised to enhance configuration management controls to ensure that insulation within that could become debris does not exceed strainer design inputs.

Procedures are in place to ensure that the single potential choke point, refueling canal drain covers, are removed prior to Mode 4 restart so that the design basis sump water supply is available

" Downstream effects evaluations confirm that no other modifications are required to ensure long-term cooling capability is maintained.

10 CFR 50, Criterion 35--Emergency core cooling. A system to " The assurance of long-term cooling Appendix A, provide abundant emergency core cooling shall be capability during recirculation GDC 35 provided. The system safety function shall be to ensures that the design basis transfer heat from the reactor core following any loss emergency core cooling capabilities of reactor coolant at a rate such that (1) fuel and clad are maintained.

damage that could interfere with continued effective core cooling is prevented and (2) clad metal-water reaction is limited to negligible amounts.

10 CFR 50, Criterion 38--Containment heat removal. A system to

The assurance of long-term cooling Appendix A, remove heat from the reactor containment shall be capability during recirculation for the GDC 38 provided. The system safety function shall be to containment spray system pumps reduce rapidly, consistent with the functioning of ensures that the design basis other associated systems, the containment pressure containment heat removal and temperature following any loss-of-coolant capabilities are maintained.

accident and maintain them at acceptably low levels.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 4 of 78 Table 1: GL 2004-02 Regulatory Compliance Regulatory Applicable Requirement Basis For Compliance Statute 10 CFR 50, Criterion 41--Containment atmosphere cleanup. The containment atmosphere clean Appendix A, Systems to control fission products, hydrogen, up system is not affected by GSI-191 GDC 41 oxygen, and other substances which may be issues because it does not rely on released into the reactor containment shall be ECCS recirculation to perform its provided as necessary to reduce, consistent with the intended function.

functioning of other associated systems, the concentration and quality of fission products released to the environment following postulated accidents, and to control the concentration of hydrogen or oxygen and other substances in the containment atmosphere following postulated accidents to assure that containment integrity is maintained.

FPL has made significant improvements in the ECCS system to address the issues identified in Generic Letter 2004-02. As part of the analysis, FPL has included a number of conservatisms to ensure sufficient margin is available. These margins are summarized below.

The new sump strainer system installed in Turkey Point Unit 4 in the spring of 2008 is a Performance Contracting, Inc., design with a surface area of approximately 3,600 ft 2 with nominal 3/32-inch perforations to retain debris. The new strainers replaced the previous sump screens which had a combined total surface area of approximately 63 ft2 with a %-inch screen mesh.

0 Debris interceptors have been installed at the exit points at the bioshield wall. These debris interceptors have been demonstrated to hold a significant amount of debris from a large break LOCA inside the biowall.

In the debris generation analysis, the ZOI used for Nukon insulation is 17D for piping and 7D for the steam generators. WCAP-16170-P testing confirmed that the zone of influence could be reduced further to 5D. As such, the strainer system was qualified utilizing a quantity of fiber that is significantly greater than is expected to be generated.

0 A uniform factor of 1.1 has been applied to the ZOI radius to ensure the calculation was conservative.

100% of unqualified coatings in the active pool, regardless of types and location inside containment, were assumed to fail as particulates and transport to the screen. EPRI and industry testing indicates some unqualified coatings do not fail and some coatings fail as chips and may not transport to the sump.

Scaling for the head loss testing was based on a strainer area of 3513.8 ft 2 (3613.8 - 100).

100 ft2 was subtracted from the total strainer area to account for miscellaneous debris such as tags and labels even though testing indicated that these items will not transport to the screen.

Turkey Point Unit 4 L-2008-160

.Docket No. 50-251 Attachment 2 Page 5 of 78

" In determining the velocity profile for testing, the CFD analysis calculated the average velocities by "double weighting" the fastest velocity at the increment under consideration.

Weighting the average by twice the fastest velocity incorporates conservatism into the calculation.

" The amount of chemicals calculated to form in 30 days were added to the test flume, and as such, a 30 day chemical effect was applied in the early stages of the event. This is extremely conservative as corrosion and formation of chemical precipitants is a time based phenomena and significant additional NPSH margin is available as the containment pool temperature decreases over time.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 6 of 78 Topic 2: General Description of and Schedule for Corrective Actions FPL Response As discussed in the previous section, Florida Power & Light Company (FPL) received a short extension to the completion schedule to extend the completion of corrective actions required by Generic Letter 2004-02 for Turkey Point Unit 4 until the spring 2008 outage. General descriptions of the actions already taken are presented below. Additional details are contained in subsequent sections of this updated supplemental response.

During Turkey Point Unit 4 fall 2006 refueling outage (PT4-23), two interim passive strainer modules were installed to supplement the existing ECCS recirculation sump debris screens in the containment building, adding approximately 462 ft2 of additional screen area at each of the north and south sumps. The installation of the interim strainer modules exceeded the screen area committed to in the January 27, 2006, letter as a mitigative measure in resolving GSI-1 91.

During the same refueling outage, debris interceptors were installed at the entrances of the biological shield wall, calcium silicate insulation was removed from the pressurizer relief tank (PRT), and modifications were made to existing penetrations in the biological shield wall.

Consistent with our approved extension request, permanent modifications were implemented during the Turkey Point Unit 4 spring 2008 refueling outage scheduled to begin on March 30, 2008. The preexisting sump screens and interim strainer modules were replaced with a single strainer system consisting of approximately 3,614 ft2 of strainer surface area. Reactor coolant pump (RCP) insulation was replaced with reflective metallic insulation (RMI). In addition, the containment spray pump mechanical seals were modified and their cyclone separators were removed.

Walkdowns to specifically identify potential choke points (upstream effects) have been completed. The upstream effects assessments confirmed that the only potential choke points are the fuel transfer canal drain covers. Plant procedures were revised to verify that the drain covers are removed prior to entry into mode 4 during startups. These revisions were made prior to entry into Mode 4 during restart from the spring 2008 refueling outage.

The downstream effects assessments of components were completed by the schedule provided to the NRC Staff in letter L-2007-155. The methodology of WCAP-16406-P, Revision 1, "Evaluation of Downstream Sump Debris Effects in Support of GSI-191," and the Staff's SE of NEI 04-07 was used to evaluate the downstream effects of bypass debris on downstream components. An additional issue with the High Head Safety Injection pumps not meeting the shaft stiffness acceptance criteria (per WCAP-1 6406-P Revision 1) was identified to the NRC, indicating that the final in-vessel and ex-vessel downstream effects analytical results would be provided to the NRC by this updated supplemental response. FPL refined the downstream High Head Safety Injection pump analysis to demonstrate the pump meets the required acceptance criteria.

The downstream effects assessments of the fuel and vessel are complete. FPL participated in the PWR Owners Group (PWROG) program to evaluate downstream effects related to in-vessel long-term cooling using the methodology of WCAP-1 6793-NP "Evaluation of Long-Term Cooling Considering Particulate, Fibrous and Chemical Debris in the Recirculating Fluid," Rev. 0. A

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 7 of 78 Turkey Point Unit 4 calculation using plant-specific parameters and WCAP-1 6793-NP methodology confirms that chemical plate-out on the fuel is acceptable. This assessment was completed in accordance with the schedule provided to the NRC Staff in FPL letter L-2007-155, dated December 7, 2007.

Several enhancements to programmatic controls have been put in place at Turkey Point.

Engineering procedures were revised to provide guidance to design engineers working on plant modifications to take into account the impact of the design on the containment sump debris generation & transport analysis and/or recirculation functions.

New controls have been instituted limiting the permissible quantity of unqualified coatings in the containment building to ensure that the ECCS strainer design requirements, as documented in the Turkey Point Unit 4 debris generation calculation, remain within permissible limits.

As an enhancement to the existing process for controlling the quantities of piping insulation within the containment, the Engineering Specification that controls thermal insulation was revised to provide additional guidance for maintaining containment insulation configuration.

Based on the latent and foreign material walkdowns performed, and a review of the existing plant procedures, it was determined that changes in the Turkey Point housekeeping procedures were not required because of the limited amount of material observed.

Chemical Effects testing to validate the design of the permanent strainers is complete.

This updated submittal describes the implemented corrective actions to resolve Generic Letter 2004-02 issues and provides the balance of the requested information not contained in the previous supplemental response. This updated submittal also addresses the balance of the RAI responses.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 8 of 78 Specific Information Regarding Methodology for Demonstrating Compliance:

Topic 3.a: Break Selection FPL Response In agreement with the staff's SE of NEI 04-07, the objective of the break selection process was to identify the break size and location which results in debris generation that will maximize the head loss across the containment sump. Breaks were evaluated based on the methodology in Nuclear Energy Institute (NEI) guidance document NEI 04-07, as modified by the staff's SE for NEI 04-07.

The Nuclear Steam Supply System (NSSS) is located between a bioshield wall near the outer wall of containment and a primary shield that surrounds the reactor cavity. The bioshield is a two-piece wall with one wall starting at the floor and extending up, and the other starting at the ceiling and extending down. The two walls are offset so that they do not intersect, which creates an opening between them due to their overlap. This opening can provide a path for jet impingement on piping outside the bioshield by breaks inside the bioshield (or vice versa). An evaluation of potential breaks and potential targets in both the inner annulus and the outer annulus concluded that this opening does not affect the selection of the limiting break.

The following specific break location criteria were considered:

Breaks in the reactor coolant system with the largest amount of potential debris within the postulated ZOI,

Large breaks with two or more different types of debris including the breaks with the most variety of debris,

Breaks in areas with the most direct path to the sump,

Medium and large breaks with the largest potential particulate debris to insulation ratio by weight, and

Breaks that generate an amount of fibrous debris that could form a uniform "thin bed."

[RAI 34] All Reactor Coolant System (RCS) piping and attached energized piping was evaluated for potential break locations. Inside the bioshield breaks in the hot legs (29-inch ID), cold legs (271/2-inch ID), crossover legs (31-inch ID), pressurizer surge line (14-inch nominal), and Residual Heat Removal (RHR) recirculation line from the hot leg (14-inch nominal) were considered. Feedwater and main steam piping was not considered for potential break locations because ECCS in recirculation mode is not required for Main Steam or Feedwater line breaks.

The other piping lines have smaller diameters (10-inch nominal maximum), which will produce a much smaller quantity of debris.

[RAI 33] Inside the bioshield the break selection process used the discrete approach described in Section 3.3.5.2 of the staff's SE of NEI 04-07. The staff's SE of NEI 04-07 notes that the concept of equal increments is only a reminder to be systematic and thorough. As stated in the staff's SE of NEI 04-07, the key difference between many breaks (especially large breaks) will not be the exact location along the pipe, but rather the envelope of containment material targets that is affected. Consistent with this guidance, break locations were selected based on the total debris, mixture of debris and distance from the sump. Containment symmetry ensures similar results for each break, but each break is also unique in certain aspects, and this was considered

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 9 of 78 in the break selection process. The crossover leg is the largest line (31-inch ID) inside the bioshield and would produce the largest ZOI. A crossover leg break is analyzed in loops A, B and C in order to maximize the ZOI radius which maximizes the insulation encircled. The crossover leg of loop C is also near the south sump pit. A hot leg break in loop B is chosen for the large surface area of coatings near it due to the proximity of the pressurizer relief tank and pressurizer surge line. A cold leg break near loop A is chosen for its proximity to several coated walls.

Outside the bioshield a break was considered in an RHR line. The RHR lines are of smaller diameter than the RCS piping. Therefore, inside the bioshield a break in these lines would be bounded by the reactor coolant loops, and thus need not be analyzed. However, the RHR recirculation line travels outside the bioshield before the second isolation valve. This location was selected in order to include a break outside the bioshield.

The postulated break locations were as follows:

S1 The Loop B Hot Leg at the base of the steam generator (29-inch ID)

S2 The Loop A Crossover Leg at the base of the steam generator (31-inch ID)

S3 The Loop A Cold Leg at the base of the reactor coolant pump (27.5-inch ID)

S4 The Loop B Crossover Leg at the base of the reactor coolant pump (31-inch ID)

S5 The RHR line from Loop A Hot Leg outside the bioshield wall (14-inch nominal)

S6 The Loop B Crossover Leg at the base of the reactor coolant pump - alternate break (11.19 inch ID)

S7 The Loop C Crossover Leg at the low point of the pipe (31-inch ID)

Based on a review of the above, the limiting break was originally selected as S2. The break was conservatively chosen to maximize the debris generated and the close proximity to the strainers. Although the initial debris generation calculations showed S2 as generating the largest amount of Nukon, it did not generate the maximum amount of calcium silicate (cal-sil).

Therefore, FPL conservatively assumed the maximum cal-sil amount of 79.85 ft 3 was generated at the S2 location and utilized this as the bounding cal-sil amount for testing. Additionally, during analytical refinements, the ZOI for the steam generator insulation was revised from 17 D to 7 D. This shifted the limiting fiber break location. Again, FPL selected a value of 315 ft3 of Nukon to bound the quantity of debris in any of the locations and applied it to the S2 break location.

In summary, the location of break 52 was determined to be the most limiting break location and the Nukon and cal-sil values assumed at this location were the maximum value at any break.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 10 of 78 Topic 3.b: Debris Generation/Zone of Influence (ZOI) (excluding coatings)

FPL Response The debris generation calculations continue to use the methodologies of Regulatory Guide 1.82, Rev. 3, and the staff's SE of NEI 04-07. However, there have been changes in the input to the analyses since the September 1 response. Subsequent to the September 1 response, a new vendor, Sargent & LundyLLc (S&L), was selected to revise the previously performed debris generation calculations.

Debris specific ZOls were used in the debris generation calculations for calcium-silicate (cal-sil),

low density fiber glass (LDFG) and reflective insulation. The following ZOls for commonly used insulation were obtained from Table 3-1 of NEI 04-07 and Table 3-2 of the staff's SE of NEI 04-07, 17 D for Nukon (fiber) insulation on piping, 7 D for Nukon (fiber) insulation on steam generator insulation, 5.45 D for cal-sil insulation, 28.6 D for Mirror reflective metal insulation (RMI), and 2.0 D for Transco/Darchem RMI. All cal-sil, Nukon and RMI insulation is jacketed.

The ZOI of insulation on the steam generators, which is jacketed, is 7 D. ZOI reduction from 17D to 7D for jacketed Nukon is supported by tests documented in WCAP-16710-P, "Jet Impingement Testing to Determine the Zone of Influence (ZOI) of Min-K and NUKON Insulation for Wolf Creek and Callaway Nuclear Operating Plants," revision 0, October 2007.

The updated debris generation calculations make use of two assumptions related to non-coating debris generation.

Assumption 1 Supporting members fabricated from steel shapes (e.g.,angles, plates) are installed to provide additional support for insulation on equipment. It is assumed that as a result of the postulated pipe break, these supporting members will be dislodged from the equipment, and may be bent and deformed, but will not become part of the debris that may be transported to the sump.

Assumption 2 In the September 1 response, it was noted that an analytical process was used that conservatively overstated the quantity of debris from insulation by 5-15%. This has since been changed to a uniform ZOI factor of 1.1 for insulation debris to account for minor variances such as small variations in the insulation analysis coordinates used for the systematic break selection process, degraded insulation, larger amounts of insulation around valves, etc.

The quantities of debris and destruction ZOI are provided in Table 3.b-1 below:

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 11 of 78 Table 3.b-1: Destruction ZOI and Limiting Break Comparison Debris Type Destruction Break S1 Break S2 Break S3 Break S4 ZOI (Note 1) (Note 1) (Note 1) (Note 1)

Nukon (piping) 17.0 D 66.95 ft3 45.05 ft33 57.01 ft3 71.62 ft33 Nukon (Steam Gen.s) 7.0 D 219.38 ft3 232.01 ft 3 105.73 ft3 118.36 ft 3 Cal-sil 5.45 D 72.02 ft3 45.86 ft 79.85 ft3 67.61 ft RMI Mirror 28.6 D 8069.49 ft2 3971.58 ft2 7878.89 ft2 2 8716.932 Darchem/Transco 2.0 D 721.6 ft2 3033.08ft ft 747.5 ft2 1860.332 2*

ft Insulation Jacketing Mirror (Note 2) 28.6 D 3149.99 ft2 2750.99 ft 2 3374.19ft 2 3411.242 2.0 D 2386.05 ft2 2602.49 ft ft Darchem/Transco 2415.18 ft2 (Note 2) 2607.472 ft Coatings 3 3 3 3 Qualified - Steel 4.0 D 1.1 ft3 1.1 ft 3 1.1 ft 3 1.1 ft 3 Qualified - Concrete 4.0 D 3.1 ft3 3.1 ft 3 3.1 ft 3 3.1 ft 3 Unqualified -Total N/A 5.06 ft 5.06 ft 5.06 ft 5.06 ft Latent Debris N/A 154.44 Ibm 154.44 Ibm 154.44 Ibm 154.44 (15% fiber, 85% Ibm particulates)

Miscellaneous Debris 2 2 2 2 Labels, Tags, etc N/A 44.5 ft2 44.5 ft 44.5 ft2 44.5 ft Glass N/A 72.0 ft3 72.0 ft 2 72.0 ft 3 72.0 ft 23 Adhesive N/A 0.03 ft 0.03 ft 3 0.03 ft 0.03 ft (Note 1): Break locations are discussed in the response to NRC Topic 3.a, Break Selection (Note 2): The manufacturer of RMI insulation on the piping is unknown, therefore two cases are provided for the piping; one as if the RMI were Mirror and one as if the RMI were Transco or Darchem

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 12 of 78 Topic 3.c: Debris Characteristics FPL Response

[RAI 35] The size distribution of generated debris is a function of the insulating material and whether it lies within the ZOI. This analysis is based on two debris sizes; Small Fines and Large Pieces, and assumes a ratio of small fines to large pieces based on debris material type. The tables below summarize the size distribution percentages for debris sources inside and outside the ZOI.

Debris Size Distribution -

Debris Source Material (Type) Inside the ZOI Small Fines Large Pieces NUKON Insulation (Fiber Blankets) (Fibrous) 60% 40%

Mirror RMI Insulation (RMI) 75% 25%

Cal-sil Insulation (Particulates) 100% --

Coatings (Particulates) 100%

Debris Size Distribution -

Debris Source Material (Type) Outside the ZOI Small Fines Large Pieces Misc. Debris (Fibrous and Particulates) 100% --

Latent Debris (Fibrous and Particulate) 100% --

Unqualified Coatings (Particulates) 100% --

The debris values for amounts, bulk densities, material densities and characteristic diameters for fibrous debris and particulates debris used in the strainer performance testing for Turkey Point Unit 4 are consistent with NEI 04-07 and recognized in the staff's SE.

The specific surface areas for fibrous and particulate debris are generally used in the prediction of head loss with the NUREG/CR-6224 correlation. Turkey Point Unit 4 does not use the NUREG/CR-6224 correlation to determine the debris bed head loss and therefore the specific surface area is not applicable.

No debris characterization assumptions that deviate from USNRC-approved guidance were utilized.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 13 of 78 Topic 3.d: Latent Debris FPL Response The bases and assumptions related to latent and miscellaneous debris, and the resulting quantities used for analyses and testing, have been updated since the September 1 response.

In that response it was noted that the quantity of latent debris was an assumed value in lieu of applied survey results, and that the sacrificial area for miscellaneous debris was independently estimated to be 50 ft 2. Subsequently, walkdowns have been completed in the Turkey Point Unit 3 containment specifically for the purpose of characterizing latent, miscellaneous and foreign debris (e.g., labels, stickers, etc.). These walkdowns utilized the guidance of NEI 02-01, Rev. 1, "Condition Assessment Guidelines: Debris Sources Inside PWR Containments" and the Staff's SE of NEI 04-07. This methodology, the results and the justification for basing Turkey Point Unit 4 latent and miscellaneous debris on Turkey Point Unit 3 data is discussed below.

The methodology used to estimate the quantity and composition of latent debris in the Unit 3 containment is that of the staff's SE of NEI 04-07, Section 3.5.2. Samples were collected from eight surface types; floors, containment liner, ventilation, cable trays, walls, equipment, piping and grating. For each surface type, a minimum of (4) samples were collected, bagged and weighed to determine the quantity of debris that was collected. A statistical approach was used to estimate an upper limit of the mean debris loading on each surface. The horizontal and vertical surface areas were conservatively estimated. The total latent debris mass for a surface type is the upper limit of the mean debris loading multiplied by the conservatively estimated area for that surface type, and the total latent debris is the sum of the latent debris for each surface type.

Turkey Point Units 3 and 4 are of similar design. The internal containment horizontal and vertical surface areas are similar. Procedures for containment closeout and the plant organizations which perform those procedures are the same for both units. For these reasons, the latent and foreign debris surveyed, measured, and calculated for the Turkey Point Unit 3 containment were used as the basis for estimating the quantity of this debris in the Turkey Point Unit 4 containment.

Based on the Turkey Point Unit 3 containment walkdown data, the quantity of latent debris in the Unit 3 containment is estimated to be 77.22 pounds. The latent debris composition is assumed to be 15% fiber and 85% particulate in agreement with the staff's SE of NEI 04-07.

However, in order to ensure the differences are bounded, the Turkey Point Unit 3 quantity is doubled to 154.44 pounds (100% margin) for Turkey Point Unit 4. Latent debris quantities are provided in Table 3.b-1 above.

A walkdown was performed in the Turkey Point Unit 3 containment for the purpose of identifying and measuring the miscellaneous (foreign) debris that constitutes the sacrificial. area (e.g.,

labels, stickers, tape, tags etc). Based on the Turkey Point Unit 3 walkdown data, the total quantity of miscellaneous debris in the Unit 3 containment is estimated to be 93.21 ft2 .

However, to account for differences, the quantity of miscellaneous debris that was determined in the Turkey Point Unit 3 walkdown was increased to 116.5 ft 2 (25% margin) for Turkey Point Unit

4. The miscellaneous debris quantities and distribution are provided in Table 3.b-1 above.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 14 of 78 Topic 3.e: Debris Transport FPL Response In the Turkey Point September 1 response it was noted that debris transport was analyzed using the computational fluid dynamics (CFD) based methodology outlined in NEI 04-07. Alden Research Laboratory (Alden) prepared a Turkey Point Unit 4 debris transport study to determine the quantities of insulation, by debris type and size, that may be transported to the containment sump during the recirculation phase of a loss-of-coolant-accident (LOCA). This study was performed prior to both the selection of Performance Contracting, Inc. (PCI) as the replacement sump strainer vendor and the installation of the debris interceptors now located at the entrances to the biological shield wall. Consequently, the CFD model and debris transport calculation were revised. The results of these revisions, including a response to RAI 41, are provided below.

In order to determine the distribution of this debris due to LOCA blowdown, containment spray washdown, and pool fill effects, debris distribution logic trees were utilized consistent with NEI 04-07. These trees are based on the physical configuration of the containment building. The results are subsequently used as design input to a separate analysis to determine the extent of debris transport to the ECCS sump by recirculation flow.

[RAI 41] The following outline presents the general methodology for performing the debris transport calculations to determine the amount of debris, classified by type and size, which may be transported to the containment sump during the recirculation phase of a loss-of-cooling-accident (LOCA). Further description of the model and boundary assumptions are provided below.

" Perform steady state Computational Fluid Dynamics (CFD) simulation for a given break scenario.

Post-process the CFD results by plotting 3D surfaces of constant velocity. These velocities will correspond to the incipient transport velocities tabulated in NEI 04/07 for the debris generated in the LOCA scenario.

" Project the extents of these 3D surfaces of velocity onto a horizontal plane to form a flat contour. Automatically digitize a closed curve around the projected velocity contour and calculate the area within the curve.

" Compare the area calculated in above to the total floor area of the zone containing the particular debris type/size under consideration. This comparison gives the fraction of the floor area susceptible to transport.

" Tabulate the results of each calculation to determine the total fraction of debris transported to the sump for each LOCA break scenario and each debris type.

The model assumes that the same equal amount of flow is drawn through all modules in the strainer. Settling velocities and incipient tumbling velocities for the small debris insulation types found in the containment are given in NUREG/CR-6772 and are summarized in NEI 04/07 Table 4-2. All coatings, latent debris, signs, stickers, tags, tape, and other miscellaneous debris in the active pool are conservatively assumed to transport 100% to the strainer modules.

Debris is assumed sequestered in inactive sumps by the ratio of the volume of inactive sumps to the total water volume in containment at the start of recirculation. However, according to

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 15 of 78 Volume 2 of NEI 04-07, the maximum reduction by the inactive sumps is limited to 15% due to the entrapment models producing an unrealistically high fraction of debris being sequestered by the inactive sumps. All transportable debris materials (insulation debris, latent debris, miscellaneous debris, and coatings) are subject to sequestration in inactive sumps by either 15% or the ratio of volumes, whichever is lesser. The debris that ends up on the upper levels is assumed to wash down completely through the available openings to the proximity zones outside the secondary bioshield.

GAMBIT Version 2.1.6 was used to generate three dimensional solid models of the containment building from the floor elevation to the selected water surface elevation. GAMBIT was also used to generate the computational mesh and to define boundary surfaces required to perform the CFD analysis. FLUENT version 6.1.22 was used to perform the CFD simulations. FLUENT is a CFD software package for modeling problems involving fluid flow and heat transfer.

The computational mesh generated in the model was about 5.6 million cells. The mesh was imported into the FLUENT CFD software program. The values for each boundary condition and the properties of the working fluid (water) are set in FLUENT. The two-equation standard k-E model was used to simulate the effects of turbulence on the flow field. The results of the steady state, isothermal flow simulations included component velocities (x, y, and z directions),

turbulent kinetic energy and the dissipation rate of turbulent kinetic energy for each cell in the computational mesh.

The following is a description of the boundary conditions used by Alden in modeling the Turkey Point Unit 4 containment sump flow patterns and velocity distributions.

Solid Surfaces - All of the solid surfaces in the containment building below the modeled water surface, including the walls, floors and structural supports, were treated as non-slip wall boundaries. At these surfaces the normal and tangential velocity components were set to zero.

Water Surface - The upper boundary of the CFD model representing the water free surface was set at an elevation of 17.01 ft. This water surface elevation corresponds to the minimum water level of a SBLOCA at the start of recirculation. This surface was modeled as a frictionless wall.

Sump Strainer Modules - It was assumed that an equal amount of flow was drawn through each of the modules. The strainer modules were modeled as velocity inlets, with uniform negative velocities applied to each module face. The net flow through these faces was equal to the sum of the spray and break flows.

LOCA Break and Spray Flows - It was assumed that the break flow falls to the pool water surface without contacting any equipment or structures. The break flow jet accelerates under the influence of gravity as it falls towards the water surface. This is a conservative method to model the break flow as it produces the greatest lateral outflow velocities along the floor. A single break corresponding to break S2 on the 31" crossover leg loop A was modeled in this simulation. Spray flow was introduced into the containment building from spray headers located in the upper containment. The spray flow was assumed to be uniformly distributed on the surface of the water.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 16 of 78 The transport calculation assumed that fines will move to the sump at any flow velocity.

Additionally, all other coatings, latent debris, signs, stickers, tags, tape, and other miscellaneous debris are conservatively assumed to transport 100% to the strainer modules.

Using the results of the CFD simulation, velocity isosurfaces and streamline plots were generated for use in predicting debris transport. Plots were generated corresponding to areas where velocities are equal to or greater than the velocities associated with incipient tumbling of the debris found in each zone. The velocity plots were obtained by projecting down onto the reactor floor the maximum lateral extent of a three-dimensional volume in which the velocities were equal to or greater than the selected incipient tumbling velocity. This method accounts for velocities at all elevations in the pool. Overlays of the velocity surface with the zone definition plots were used to determine the floor area which would be susceptible to transport for each break location. Streamline plots were used to identify isolated eddies that had velocities higher than the incipient tumbling velocity but did not contribute to debris transport from the zone; these areas were not credited to the recirculation transport fraction. The fraction of the zone floor area that is susceptible to transport constitutes the recirculation transport fraction for each debris type. The total fraction of small debris transported to the strainer from each zone is determined by the following equation:

Fraction of Debris Transported to Strainer Per Zone =

Erodible Fraction + (1 - Erodible Fraction)(Transport Fraction)

The debris interceptors installed at Turkey Point Unit 4 were not modeled into the debris transport model. Specific debris interceptor testing was performed at Alden Laboratories to determine how much Nukon insulation debris would be retained. The test report for the efficiency of the debris interceptors showed that 88% of fibrous debris was effectively retained.

The results of this test were applied to the transported quantities of Nukon insulation and the results are provided in the table below. Note that the debris interceptors were only credited to retain Nukon insulation (not coatings or other particles).

The following table summarizes the results of the transport analysis:

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 17 of 78 Debris at Sump Strainer Modules for Limitinq Case Break S2 Debris Type Quantity Generated Quantity at (From Table 3.b-1) (From Table 3.b-1) Strainer Fiber (Nukon) (Note 1) 315ft3 37.8 ft3 RMI 6,722.57 ft32 3,903.13 ft23 Cal-sil 79.85 ft 49.08 ft Coatings (Note 2) 3 9.26 ft 9.06 ft 3 Latent debris 154.44 lb 131.3 lb Miscellaneous (Note 3) 116.49 ft2 99 ft 2 Note: 100% of coatings in the active pool are assumed to transport.

Note 1: The quantity at the strainers considers the debris interceptors.

Note 2: The debris transport calculation showed that 15% of the coatings would be retained in inactive pools. The quantity at the strainer shown in the table above was used for testing and is conservative.

Note 3: 100 ft2 was deducted from the total strainer area to account for miscellaneous debris such as tags and labels. Scaling for testing was based on this reduced value.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 18 of 78 Topic 3.f: Head Loss and Vortexing FPL Response A piping schematic of the ECCS and containment/reactor building spray systems is provided in Figure 3.f-1 below. A description of the strainer system including the capability to accommodate thin bed effects is provided in the response to NRC Topic 3.j, Screen Modification Package.

A calculation was performed for air ingestion and void fraction. The acceptance criteria for air ingestion was less than or equal to 2%, in accordance with Regulatory Guide 1.82, revision 3.

The acceptance criteria for void fraction was less than or equal to 3% in accordance with Volume 2 of NEI 04-07. The calculated values for air ingestion and void fraction were zero.

The strainer head loss testing was performed at the Alden Research Laboratory, Inc. facility in Holden, Massachusetts. The test apparatus included a test flume, two pumps, a prototype strainer, instrumentation and controls, and associated piping and valves needed to complete a recirculation loop with the pumps is a parallel setup, a chemical mixing tank, a pump designated to pump the chemical debris into the test flume, and associated piping and tubing. As debris was added and the water in the flume displaced, an over flow captured the debris for reintroduction into the test flume.

Scaling for testing was done to determine the debris loads and the flow rates for the test. The final strainer design has an area of 3613.8 ft 2. To account for labels and tags potentially blocking the screen area 100 ft2 was subtracted from this area. The strainer module used for testing had an area of 240.92 ft 2 . The scaling factor for debris and flow was 240.92 divided by 3513.8 (3613.8 - 100), or 0.068564. There are two maximum flow rates at Turkey Point Unit 4, 2697 gpm prior to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months and 3750 gpm after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . For the purpose of head loss testing, the flow rate of 3750 gpm is applicable. Debris quantities were based on calculated values, the debris transport calculation, the debris interceptor testing, and conservative decisions to ensure the maximum head loss was determined. The head loss test was an integrated test that introduced calculated quantities of both debris and chemical precipitates. The test flume was configured to accommodate the Turkey Point Unit 4 strainer module and simulate the fluid flow to the module based on the Turkey Point Unit 4 specific CFD model. The termination criteria for the test was the change in head loss was less than 1% in the last 30 minute interval and a minimum of 15 flume turnovers after all the debris had been inserted into the test flume. This testing is further described in Topic 3.0.

The results of the test showed a relatively small head loss, 1.06 ft of water due to the design basis debris loading including chemicals. This value is based on maximum flow of 3750 gpm and a water temperature of 100.7 0 F.

Note that a specific test was performed with fiber only. After introducing the design basis amount of Nukon fiber an additional amount of 1.5 lb was introduced. The test flume was drained. The majority of the screen surface was free of fiber.

The basis for the strainer design maximum head loss is adequate NPSH margin for the RHR/LPSI pumps. These are the only pumps that take suction from the containment sump

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 19 of 78 during recirculation. This margin was determined to be a minimum of 6.53 ft. The following methodology/assumptions were utilized:

" The total head loss calculation was based on testing for the strainer head loss and a separate calculation for the clean strainer head loss that included the piping and fittings.

The test for the strainer head loss was scaled based on a strainer area reduced by 100 ft2 to account for miscellaneous such as tags and labels. Testing showed that this type debris would settle and not reach the strainer.

" The test results for the strainer head loss attributed to the debris bed were adjusted for temperature using the dynamic viscosities at the test temperature and at the design temperature. The flow across through the debris is laminar and the head loss, therefore, is proportional to the dynamic viscosity.

The clean strainer head loss was determined at a maximum flow of 3750 gpm at a maximum temperature of 170'F. It was also determined at a flow of 2697 gpm at a temperature of 300'F. The calculated value for the clean strainer head loss, strainer piping and fittings, fittings connected to the plenum box and the transfer piping and fittings, includes a 6%

uncertainty factor for the strainer assembly and a 10% uncertainty factor for the connecting plenum and fittings.

" Two distinct methodologies were used to calculate head loss. The first methodology for strainer only head loss, employed an equation that was experimentally derived, and which was used to determine the strainer head loss contribution. The second methodology utilized classical standard hydraulic head loss equations for the plenum and fitting to determine the total head loss contributions of the strainer, plenum, and fittings. The individual head loss results from the strainer, plenum, and fittings were added together to obtain the head loss of the entire strainer assembly configuration. The clean strainer head loss was 1.76 ft. at a flow of 3,750 gpm and 170'F and 0.91 ft. at a flow of 2697 gpm and 300'F.

" The debris head loss was determined by testing.

Containment accident pressure was not credited in evaluating whether flashing would occur across the strainer surface. The pressure of containment was assumed to be the minimum allowable partial pressure of air at the start of the accident adjusted for temperature plus the vapor pressure equivalent to the temperature of the sump water. The potential for flashing was examined for a temperature range of 650 F to 300 0 F.

[RAI 36] Debris settling upstream of the sump strainer, the near field effect, was credited during testing to support the design basis. The debris transport characteristics of miscellaneous debris, tags, labels, stickers, tape, RMI etc., were tested. Heavy debris tested for transport characteristics was excluded from the final integrated test if the results of the debris transport test illustrated that the heavy debris settles and/or does not transport to the strainer. This was considered conservative since the heavy debris may entrap debris that may tumble along the flume floor.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 20 of 78 The debris transport test showed that RMI and miscellaneous debris, labels, stickers, tape, placards, tags, and glass, settled in the test flume and did not reach the strainers. 100% of this debris settled and was not included in further tests.

[RAI 39] The strainer system is described in the response to NRC Topic 3.j, Screen Modification Package.

The total strainer system head loss was evaluated for two recirculation flow conditions. For the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after a LOCA, the maximum flow rate is 2697 gpm. After 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months the maximum flow rate is 3750 gpm. The debris laden head loss determined by testing was 1.06 ft. of water.

This head loss does not include the clean strainer head loss or the fitting losses. This head loss was determined at an average temperature of 100.7°F. The table below shows the head losses at a temperature of 170'F for 3750 gpm and 300°F for 2697 gpm. This table includes the results of testing and calculations to determine the total head loss.

Table 3.f-1: Strainer System Head Loss Summary Temperature corrected Condition Flow Temp Strainer Piping Total Rate OF Head Loss Head Loss Head Loss (gpm) (ft) (Note 1) (ft) (ft)

Debris Laden (< 24 hours) 2,697 300 0.313 0.886 1.199 Clean (< 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ) 2,697 300 0.024 0.886 0.91 Debris Laden (< 24 hours) 3,750 170 0.628 1.712 2.340 Clean (< 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ) 3,750 170 0.048 1.712 1.76 Note 1: These values are based on the head loss testing at a flow rate corresponding to 3750 gpm, which is conservative.

The remaining margin for head loss is based on the effect on net positive suction head. NPSH was determined for two cases. Case 1 is for a flow of 2697 gpm, which occurs up to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months post LOCA. Case 2 is for a flow of 3750 gpm, which occurs after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months post LOCA. For Case 1 the minimum NPSH margin is 6.53 ft and occurs at a temperature of 196.5 0 F. For Case 2 the minimum NPSH margin is 7.22 ft. and occurs at a temperature of 170 0 F. The contribution of the containment atmosphere pressure for the calculation was the partial pressure of the air in containment at the start of the LOCA or the vapor pressure equivalent to the sump temperature, whichever was greater. The partial pressure of the air in containment at the start of the LOCA was based on a maximum air temperature of 125°F, 100% humidity, and minimum allowable pressure. The pressure of this volume of air was adjusted based on temperature.

[RAI 40] The strainer module tests were conducted at a test submergence of 3 inches versus the minimum submergence of 3.36 inches for a SBLOCA and 7.2 inches for a LBLOCA. No vortexing or air ingestion was observed. Also, during the test the water level was dropped and the strainer was observed for vortexing. At the scaled flow rate to represent the maximum strainer of 3750 gpm no vortexing was observed when the water level reached the top of the perforated plate.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 21 of 78 Fiqure 3.f-1: ECCS/CSS Pipinq Schematic UNIT4 RWST (This Unit 3 Fiqure is tyDical of Unit 4 as well)

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 22 of 78 Topic 3.g: Net Positive Suction Head (NPSH)

FPL Response Following a large break LOCA (LBLOCA) both trains of the RHRJLow Head Safety Injection (RHR/LHSI) Pumps and High Pressure Safety Injection (HHSI) pumps are automatically started on a safety injection signal (SIS). Both Containment Spray (CS) pumps are automatically started on a containment high pressure signal (CHPS). Recirculation is initiated manually on the refueling water storage tank (RWST) low level alarm, which occurs at approximately 30 minutes after the LBLOCA. At the changeover to recirculation both RHRILHSI pumps are manually stopped and switched over from the RWST to the recirculation sump. One RHR/LHSI pump is then manually restarted. At this point, the CS and HHSI pumps continue to draw water from the RWST although one CS pump is manually stopped. When the RWST level reaches 60,000 gallons the HHSI and CS pumps are manually stopped and aligned to take suction from the RHR/LHSI pumps ("piggyback" mode), and one HHSI pump is restarted.

Following a small break LOCA (SBLOCA) both trains of the RHR/LHSI Pumps and HHSI pumps could automatically start if an SIS is received. Both Containment Spray (CS) pumps could automatically start if a CHPS is received. If the recirculation phase is entered, suction to the safety injection pumps is provided by the RHR/LHSI pumps as in the LBLOCA. For a SBLOCA where the RCS pressure is above the RHR/LHSI shut-off head, the RHRILHSI pumps will not deliver flow into the RCS during the injection phase. Under these conditions the time to recirculation, which is based on the RWST level, is increased beyond the LBLOCA value of approximately 30 minutes.

The range of SBLOCA breaks includes those that require recirculation from the containment sump as well as those that permit the operators to depressurize the RCS and initiate the shutdown cooling mode of decay heat removal, which does not require suction from the containment sump. Because the SBLOCA produces less debris, the debris load on the sump strainers is less than the design basis debris load. However, for the purpose of evaluating the sump strainer under SBLOCA conditions, it is conservatively assumed that the recirculation flow from the containment sump and the debris load are the same as the LBLOCA, and that the water level is that of the SBLOCA.

Contrary to the usual single failure analyses for safety analysis which are postulated to minimize overall safeguards flows, the failure mode postulates for the containment sump strainer design are most limiting when ECCS/CS recirculation flows from the post-LOCA containment pool are maximized, or when the overall available suction strainer area is minimized, thus maximizing strainer head losses and reducing the safeguards pumps overall (NPSH) margin.

The alignment of the ECCS and CS from the injection mode to the recirculation mode of operation is accomplished entirely by manual action in accordance with Emergency Operating Procedures (EOPs). A detailed single failure analyses was performed to determine the worst case single failure. The analysis considered each component action requiring manipulation or mechanical action dictated by EOPs and documented the component, the postulated failure mode, resultant outcome and net incremental recirculation flow effect. Two postulated scenarios involving valve alignment failures (RHR cold leg header isolation valves and RHR alternate discharge isolation) were determined to be the worst case single failures. The evaluation concluded that the Turkey Point ECCS/CS recirculation strainer design flow bounds the worst case postulated single failures of this evaluation.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 23 of 78 The minimum sump water level is 17.35 feet for the LBLOCA and 17.03 feet for the SBLOCA.

The assumptions made in the calculation for minimum containment sump level are as follows:

" The initial RWST level is assumed to be at the minimum Tech. Spec. level.

" The worst case instrument error is assumed.

The RWST inventory is reduced by the equivalent water volume needed to make up the LOCA steam/air mixture.

For the large break accident the vessel is considered to be flooded, thus the volume of the vessel, RCS piping, and reactor coolant pumps is not included in the sump water.

The RWST volume is reduced by the volume required to fill the containment spray piping.

The RWST volume is reduced by the volume to fill the sump water solid.

The calculation of the water condensation film on all passive heat sink surfaces exposed to air in the containment utilizes the conservative heat sink areas. The thickness of the film is based on classic laminar film condensation calculations. Conservatively, the average thickness plus 10% was used

" The water held up inside containment as spray droplets was calculated utilizing the containment spray flow, the droplet fall distance, and droplet terminal velocity.

During a SBLOCA the volume of the RWST water spills to the containment floor.

A 20% margin is added to the combined length of containment spray piping to account for small bore piping and configuration differences.

The remaining net volume, after the above adjustments, was divided by the free area above 14 ft elevation to determine the minimum corresponding water height within the containment. For conservatism, the volume occupied by equipment other than the vessel and large concrete structures will not be considered.

The following table provides a summary of the water sources:

Table 3.q-1 Post-LOCA Containment Pool Water Sources Component Water Volume Sources ft 3 - LBLOCA ft3 _ SBLOCA Steam Generators: 2,805 N/A Pressurizer 780 N/A Pressurizer Relief Tank 1,300 N/A Accumulator Tanks 2,625 N/A Reactor Vessel 3,667 N/A RCS Piping 783 N/A Reactor Coolant Pumps 192 N/A Total volume inside containment at LOCA t=0 10,852 0 Refueling Water Storage Tank: 42,778 42,778 Total volume inside containment at initial RAS (recirculation actuation signal) = 53,630 42,778 The LBLOCA sump flow rates used to calculate the NPSH margin are 2697 gpm for the period prior to 24 hrs and 3750 gpm after 24 hrs, which are the same as those used to determine the strainer system head loss discussed in the response to NRC Topic 3.f, Head Loss and

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 24 of 78 Vortexing. In recirculation mode, the CS and HHSI pumps operate in "piggyback" mode on the RHR/LHSI pumps. Therefore they are already included in the RHR/LHSI pump flow.

Containment accident pressure input s consistent with Regulatory Guide 1.1 The temperature ranges used to calculate the NPSH margin are 65 OF to 300 OF for the period prior to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , and 65 OF to 170 OF for the period after 24 hrs. The minimum NPSH margin occurs at a temperature of approximately 200 OF.

With chemical effects, for a flow of 2,697 gpm and temperature range of 170 to 300 0 F, the minimum NPSH margin is 6.53 ft and occurs at a temperature of about 200 0 F. For a flow of 3,750 gpm and temperature range of 65 to 170 0 F, the minimum NPSH margin is 7.22 ft and occurs at a temperature of 170°F. The NPSH required (NPSHR) is based on pump test curves

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 25 of 78 Topic 3.h: Coatings Evaluation FPL Response At Turkey Point Unit 4, coatings are classified as qualified/acceptable, or unqualified. The qualified/acceptable coating systems used in the Turkey Point Unit 4 containment are listed in Table 3.h-1 below.

Table 3.h-1 Qualified/Acceptable Coatinqs in the Turkey Point Unit 4 Containment Application Coating Substrate Application Thickness Product (mils)

Steel 1 st Coat Carboguard 890 6 2 nd Coat Carboguard 890 6 1 st Coat (Note 1)

Carbozinc 11 4.5 2 nd Coat (Note 1) Phenoline 305 5 Concrete Floor 1st Coat Carboguard 2011S 50 2 nd Coat Carboguard 890 7 3 rd Coat Carboguard 890 7 1 st Coat (Note 1) Phenoline 305 4.5 Concrete Primer 2 nd Coat (Note 1) Phenoline 305 4.5 Concrete Wall 1st Coat Carboguard 2011S 35 2 nd Coat Carboguard 890 7 3 rd Coat Carboguard 890 7 1 st Coat (Note 1) Phenoline 305 Concrete Primer 2 nd Coat (Note 1) Phenoline 305 4.5 Note 1: Specified thickness of original coatings. Repaired coatings are thicker, and the debris generation is based on the application coating thicknesses of the repair coatings Selected features of the treatment of qualified and unqualified coatings in the determination of coating debris that reaches the sump strainers have been updated since the September 1 response. These changes are discussed individually below.

[RAI 30] As discussed in previous sections, FPL conducted integrated chemical effects testing in a large flume on the Turkey Point Unit 4 strainer design. This test addressed the maximum debris generation and a minimal debris generation case that can produce the "thin bed effect."

Based on debris generation and transport calculations, enough debris could reach the strainer to form thin bed. Consistent with the staff's SE of NEI 04-07 for thin fiber bed cases, all coating debris is treated as particulate with 100% transportation of active pool coatings to the sump screen. Treating all coatings as particulates conservatively maximizes transport to the screen.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 26 of 78 In order to ensure testing was conservative, a test was performed where 125% of the coatings that could potentially fail as chips were introduced into the flume. This was in addition to the particulates that were added assuming 100% of the coatings failed as particulates. The results of this test showed a negligible increase in head loss, which validates the coatings assumptions are bounding.

Assumptions made and/or data used to justify use of surrogates are as follows:

Particles of "like" size, shape and density will perform in the same way as other particles of "like" size, shape and density.

Particles of similar size that are less dense will suspend more easily, and when added to the debris mix at the postulated mass of the actual coating material is bounding and conservative for these tests.

Particles of smaller sizes will bound particles of larger sizes. This is because smaller particles can fill more of the interstitial spaces between fibers than will larger particles; which will increase head loss on a relative scale.

Zinc has a specific density of 457 lb/ft3 and tin has a specific density of 455.1 lb/ft 3 .

" Walnut shells have a density range of 74.9 to 93.6 lb/ft3 .

Walnut shell flour (based on density, size, shape, texture, etc.) was determined to be a bounding and conservative surrogate material for coatings with densities above 75 Ibs/ft 3, and was utilized for coatings such as epoxy, enamel, acrylic, and alkyd coatings. For inorganic zinc coatings (including primers), the use of tin powder was utilized as an acceptable surrogate.

[RAI 29] The qualified coating ZOI in the September 1 response for Turkey Point Unit 4 was 1OD. The ZOI for qualified coatings has subsequently been reduced to 4D. The 4D ZOI is based on testing that was completed at the St. Lucie Plant during February of 2006. A description of the test, the test data, and the evaluation of the test data were previously provided to the NRC Staff for information on July 13, 2006 in letter L-2006-169 (R. S. Kundalkar (FPL) to M.G. Yoder (NRC), "Reports on FPL Sponsored Coatings Performance Tests Conducted at St.

Lucie Nuclear Plant"). The evaluation of the test results confirms that a 4D ZOI is applicable to the in-containment qualified coating systems at Turkey Point Unit 4. As stated in the test plan, heat and radiation increase coating cross linking, which tends to enhance the coating physical properties. Therefore, since artificial aging, heat or irradiation to the current plant conditions could enhance the physical properties and reduce the conservatism of the test, the test specimens were not aged, heated or irradiated.

The coating thicknesses in the September 1 response were assumed to be 3 mils of inorganic zinc primer plus 6 mils of epoxy (or epoxy-phenolic) top coat for qualified coatings and 3 mils of inorganic zinc (IOZ) for unqualified coatings. Subsequently the analyses have been updated, and now conservatively assume the maximum thicknesses for each applicable coating system.

The coating area in the ZOI in the September 1 response was assumed to be equal to the surface area of the ZOI. Subsequently, the updated debris generation calculations calculate the quantity of qualified coatings for each break by using the concrete and steel drawings to determine the amount of coating that will be within the ZOI for each break. Coatings that are shielded from the jet by a robust barrier are not included in the total. The calculated volume of qualified steel coating is then increased by 10% to account for small areas of additional items such as piping, pipe/conduit/HVAC/cable tray supports, stiffener plates, ladders, cages, handrails, and kick plates.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 27 of 78 The quantity of unqualified/failed coatings in the September 1 response was 6 ft 3.

Subsequently, with the changes discussed above, the total quantity of unqualified/failed coatings is now 9.26 ft 3.

Since the September 1 response the process for controlling the quantity of degraded qualified coatings in containment has been enhanced to ensure that the quantity of degraded qualified coatings does not exceed the design basis.

The previous program for controlling in-containment coatings was described in the FPL response to NRC Generic Letter 98-04, "Potential for Degradation of the Emergency Core Cooling System and the Containment Spray System After a Loss-of-Coolant Accident Because of Construction and Protective Coating Deficiencies and Foreign Material in Containment" in letter L-98-272 on November 9, 1998. The letter summarized the program in place at that time for assessing and documenting the condition of qualified/acceptable coatings in primary containment at Turkey Point Units 3 and 4.

[RAI 25] The current program for controlling the quantity of unqualified/degraded coatings includes two separate inspections by qualified personnel during each refueling outage, and notification of plant management prior to restart if the volume of unqualified/degraded coatings approaches pre-established limits.

The first inspection takes place at the beginning of every refueling outage when all areas and components from which peeling coatings have the potential for falling into the reactor cavity are inspected by the FPL Coating Supervisor. The second inspection takes place at the end of every refueling outage when the condition of containment coatings is assessed by a team (including the Nuclear Coating Specialist) using guidance from EPRI Technical Report 1003102

("Guidelines On Nuclear Safety-Related Coatings," Revision 1, (Formerly TR-1 09937)). All accessible coated areas of the containment and equipment are included in the second inspection. Plant management is notified prior to restart if the volume of unqualified/degraded coatings approaches pre-established limits.

The initial coating inspection process is a visual inspection. The acceptability of visual inspection as the first step in monitoring of Containment Building coatings is validated by EPRI Report No. 1014883, "Plant Support Engineering: Adhesion Testing of Nuclear Coating Service Level 1 Coatings," August 2007. Following identification of degraded coatings, the degraded coatings are repaired per procedure, if possible. For degraded coatings that are not repaired, areas of coatings determined to have inadequate adhesion are removed, and the Nuclear Coatings Specialist assesses the remaining coating to determine if it is acceptable for use. The assessment is by means of additional nondestructive and destructive examinations as appropriate.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 28 of 78 Topic 3.i: Debris Source Term FPL Response Information related to programmatic controls for foreign materials was provided to the NRC in previous submittals. Such information was provided in letter L-2003-201 which responded to NRC Bulletin 2003-01, and most recently in letter L-2005-181 which responded to GL 04-02. In general, the information related to programmatic controls that was supplied in these responses remains applicable. However, since the September 1 response, modifications, tests and walkdowns have been completed and these have been used to update the programmatic controls that support the new sump strainer system design basis.

To maintain the required configuration of the containment recirculation function that supports the inputs and assumptions utilized to perform the mechanistic evaluation of this function, Turkey Point Unit 4 has implemented programmatic and process controls as described below.

FPL has implemented a number of actions to enhance containment cleanliness as documented in the response to Bulletin 2003-01. Detailed containment cleanliness procedures exist for unit restart readiness and for containment entry at power. These procedures incorporate the industry guidance of Nuclear Energy Institute (NEI) 02-01, Revision 1 to minimize miscellaneous debris sources within the containment. The requirements to assure that the containment is free of loose debris and fibrous material, and that items not approved for storage in the containment are removed, are specifically addressed. Detailed containment sump inspections are performed at the end of each outage. Plant procedures also require that the Plant General Manager and the Site Vice President perform a detailed walkdown of the containment prior to entry into Mode 4 at the end of each refueling outage to ensure plant readiness.

The results of the recently completed walkdowns performed at Turkey Point Unit 3 (which is representative of Turkey Point Unit 4) to assess the quantities of latent and miscellaneous (foreign) debris are discussed in the response to NRC Topic 3.d, Latent Debris. These walkdowns were conducted without any preconditioning or pre-inspections. Consequently, the debris found during the walkdowns is characteristic of approximately 34 years of operation under the existing housekeeping programs. Given the small quantity of latent and miscellaneous debris after approximately 34 years of operation under the current housekeeping program, it is concluded that the current housekeeping program is sufficient to ensure that the new strainer system design bases will not be exceeded.

Programmatic controls of containment coatings are described in NRC Topic 3.h, Coatings Evaluation.

The process for controlling insulation and other materials inside containment was strengthened prior to December 31, 2007. This included updating engineering procedures to require: (a) a review of changes to insulation or other material inside containment that could affect the containment sump debris generation and transport analysis and/or recirculation functions and (b) a review of the effect of a design change package for its impact on containment sump debris generation and transport. In addition, the thermal insulation engineering specification which provides general guidance on insulation control was revised to require that material changes within the containment be reviewed for affect on post-accident PWR sump blockage issue (GSI-191) assumptions and evaluation. These procedural controls are sufficient to ensure that the new strainer design basis will not be exceeded. However, subsequent to these procedure and

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 29 of 78 specification updates it was determined that it would be advantageous to provide additional guidance for maintaining the containment insulation configuration in the insulation engineering specification. The insulation engineering specification was enhanced to require that insulation modifications for new piping be addressed in an approved engineering document. This engineering document will evaluate the type and amount of insulation added/removed to the containment and the change/addition will be reconciled via a calculation revision to contain accurate inventory of potential debris. The revision also requires that repairs to damaged or missing insulation will be performed in accordance with the insulation engineering specification to track insulation configuration. Insulation changes that are not like-for-like will be reconciled against the containment insulation volume calculation. This additional guidance employs the insulation information that was obtained for the debris generation calculations by Turkey Point systems and design engineers via walkdown during outage PT4-20. The guidance in the insulation specification supplements the procedural guidance that was already in place.

As was done as part of the implementation of the already installed Turkey Point Unit 3 replacement strainers, the engineering design package process will ensure that procedures such as containment closeout inspection and containment recirculation sump strainer inspection are reviewed and updated (or replaced) as necessary based on the requirements of the final strainer design.

One new procedure has been written for inspection of the new strainer system, and the containment close-out procedure has been updated. The new procedure requires that there are no holes or gaps greater than 3/32 inch (0.095 inch) in the strainers. The new procedure includes all of the new strainer system components in the final containment closeout inspection.

The second debris source term refinement discussed in Section 5.1 of NEI 04-07, "Change-out of Insulation," was utilized to improve the debris source terms and is summarized below:

During refueling outage PT4-23 (fall 2006), the calcium silicate insulation on the pressurizer relief tank was removed as committed to in Attachment 1 of letter L-2006-028 dated, January 27, 2006. Debris interceptors were installed in five (5) separate locations to limit debris transport from the inside to the outside bioshield.

During refueling outage PT4-24 (spring 2008) the thermal insulation on the reactor coolant pumps were replaced with reflective metallic insulation to reduce the quantity of insulation debris.

In accordance with 10 CFR 50.65 (Maintenance Rule), PTN-4 maintenance activities (including associated temporary changes or temporary system alterations) are controlled by plant procedure. This process maintains configuration control for non-permanent changes to plant structures, systems, and components while ensuring the applicable technical reviews and administrative reviews and approvals are obtained. If, during power operation conditions, the temporary alteration associated with maintenance is expected to be in effect for greater than 90 days, the temporary alteration is subject to the requirements of 10 CFR 50.59 prior to implementation maintenance activities. Associated temporary changes are also assessed and managed in accordance with the Maintenance Rule, 10 CFR 50.65.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 30 of 78 Topic 3.j: Screen Modification Package FPL Response During Turkey Point Unit 4 refueling outage PT4-23 (fall 2006), two passive strainer modules were installed to supplement the existing ECCS recirculation sump debris screens in the containment building, adding approximately 462 ft2 of additional screen area at each of the north and south sumps. The interim strainer modules consist of a series of vertically oriented passive disk sets stacked on a horizontal axis. Piping is routed from the discharge of each strainer module to its respective sump. The installation of the interim strainer modules exceeded screen area committed to in the January 27, 2006 letter as a mitigative measure in resolving GSI-191.

During the Unit 4 fall 2006 refueling outage (PT4-23), debris interceptors were installed at the entrances of the biological shield wall, and modifications were made to existing penetrations in the biological shield wall.

The original Turkey Point Unit 4 sump screens and interim strainers discussed above were completely removed and replaced with the strainer system described below during the spring 2008 refueling outage (PT4-24).

The replacement strainers are a Performance Contracting, Inc (PCI), Inc Sure-Flow suction strainer assemblies design. The replacement PCI design consists of three (3) strainer module assemblies designated as A, B, and C. Each of the three (3) strainer assemblies consist of five (5) modules. Each module has thirteen (13) disks. All disks have a 48 inch width, 30 inch height, and a nominal one-half (1/2) inch thickness. Each disk is separated by a screened 1-inch gap resulting in twelve (12) gaps for each module. Each strainer assembly has a total of 1,204.6 ft 2 of strainer surface area. The strainers have the same components except for varied core tube hole patterns.

Strainer assembly A connects directly through piping to a common plenum box over the south sump. Strainer assemblies B and C merge together and connect through an 18-inch diameter "lateral T" and piping to the same common plenum box over the south sump. The strainer system and interconnecting piping is located on the 14 foot elevation of the containment building.

The A, B, and C horizontally oriented strainer assemblies have a total strainer area of approximately 3,614 ft 2. The proposed layout of the replacement strainer system is shown in Figure 3.j-1. A typical strainer assembly is illustrated in Figure 3.j-2.

[RAI 32] The strainer design is completely passive (i.e., they do not have any active components or rely on backflushing). In addition, there are no plans to incorporate any other active approaches.

As in the original screen design, the new distributed strainer system serves both ECCS suction intakes. The original ECCS intake design has a permanent cross-connection downstream of the containment ECCS sump inlets (outside the containment), which permits either train to draw from both ECCS sump inlets. The new strainer design provides a pathway inside the containment that is parallel to the original cross-connection. Because the original Turkey Point Unit 4 design contained this ECCS cross-connection, the new design is not a departure from the existing design basis. It is consistent with the current design basis, Technical Specifications

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 31 of 78 and regulatory commitments for Turkey Point Unit 4. The new strainer system is sized for the full debris load and full ECCS flow from the ECCS/CSS systems (design basis flow is discussed in the response to NRC Topic 3.f, Head Loss and Vortexing.) Because a single non-redundant strainer system is used, the system was designed such that there is no credible passive failure mechanism that could render both ECCS trains inoperable. Active strainer failure mechanisms are not considered because the strainer system is completely passive. The strainer system structural design is discussed in the response to NRC Topic 3.k, Sump Structural Analysis.

The strainer assemblies are composed of individual disks formed by a perforated plate, bolted together in horizontal stacks with intermediate stiffener support plates and a core tube for the flow of water to the sumps via the interconnecting piping. The strainer perforations are nominal 3/32-inch diameter holes. The strainer system is designed for retention of 100% of particles larger than 0.103 inches. The entire strainer system is designed and situated to be fully submerged at the minimum containment water level during recirculation.

The capability of the strainer system to accommodate the maximum mechanistically determined debris volume was confirmed by a combination of testing and analysis. The volume of debris at the screen is discussed in the response to NRC Topic 3.c, Debris Characteristics. The capability to provide the required NPSH with this debris volume is discussed in the response to NRC Topic 3.g, Net Positive Suction Head (NPSH). The capability to structurally withstand the effects of the maximum debris volume is discussed in the response to NRC Topic 3.k, Sump Structural Analysis.

The debris interceptors were installed in five separate locations that limit debris transport from inside to the outside of the containment biowall during the previous refueling outage. Figure 3.j-3 illustrates the arrangement to the debris interceptors in the Turkey Point Unit 4 containment.

The debris interceptors including anchors and fasteners are composed of stainless steel. They have a maximum height of 33.5 inches which is less than the minimum containment post-LOCA water level. The debris interceptors function by filtering debris having a size large enough to be retained by the debris interceptor screens. The interceptor roof panel increases the amount of debris retained by the debris interceptor system by limiting movement of debris over the top with the fluid. Movement of debris over the top of the debris interceptor is inhibited due to the volumes of low flow velocities and stagnation created by the roof where debris would settle out.

Recirculation fluid will flow through the holes in the interceptors and over the top of the roof of the interceptors. Debris may bypass these interceptors if it is smaller than the interceptor hole size, light enough to float, or has a large enough effective flow area such that the flowing fluid can drag it over the top of the interceptor roof. Debris that bypasses the debris interceptors will be filtered by the replacement strainers. The debris interceptor function was included in the plant design basis.

An additional modification necessitated by the sump strainer modification created a cylindrical core bore approximately 151/2 feet long beneath the refueling cavity (also known as the fuel transfer canal) to provide a pathway for the piping that connects the strainer assemblies to the south ECCS sump suction inlet. This core bore is located between the north and south ECCS recirculation sump inlets in Figure 3.j-1. The core bore was implemented during the spring 2008 refueling outage when the replacement strainers were installed.

The modification that installed the strainers also relocated two flow transmitters to a more

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 32 of 78 accessible location to facilitate periodic calibration. The installed location of strainer C would have prevented access to these flow transmitters.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 33 of 78 Fiqure 3.i-1: Turkey Point Unit 4 Sump Strainer System PARTIAL PLAN VIEW

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 34 of 78 Fiaure 3.J-2: Turkey Point Unit 4 Strainer Assembly (TvricaI)

Y=

FLOOD WATER ELEV. 17.01' j II III IL TYPICAL STRAINER ELEVATION VIEW IL n FLOOR ELEV. 14'-0"

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 35 of 78 Ficaure 3.J-3: Turkey Point Unit 4 Debris Interceptor Arranaement

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 36 of 78 Topic 3.k: Sump Structural Analysis FPL Response The previous sump strainer system has been completely replaced by a new strainer system as described in the response to NRC Topic 3.j, Screen Modification Package.

The new strainer system is located between a bioshield near the outer wall of containment and a primary shield that surrounds the reactor cavity. The bioshield is a two-piece wall with one wall starting at the floor and extending upwards, and the other starting at the ceiling and extending down. An evaluation of potential breaks and potential targets in both the inner annulus and the outer annulus concluded that there are no concerns for the strainer system with respect to pipe whip or high energy line breaks.

The system only operates once the containment is filled with water and the entire system is fully submerged. The system is also designed to vent during containment flood up, and there is no requirement to be leak tight. That is, the strainers and piping are not pressure-retaining vessels, but rather are required to guide the screened water to the pump suction lines while fully submerged. However, the strainers and associated piping have been designed to withstand a crush pressure of 14 psi. The maximum debris ionlý head loss experienced by the strainers is 0.628 A. of water, which is much less than the design crush strength. Note that this head loss is at 170°F and 3750 gpm. This head loss will increase as the sump temperature cools based on viscosity scaling. However, the head loss across the strainer surface will remain small compared to the design crush pressure.

The strainer assemblies are passive and do not employ mechanical or hydraulic cleaning or flushing following a LOCA. Therefore, there are none of these forces on the strainers.

The potential loads for the Operating Basis earthquake and Safe Shutdown Earthquake load combinations for the strainer system are provided in Table 3.k-1.

Table 3.k-1 Potential OBE and SSE Load Combinations Load Loads Allowable Applicable Environmental Combination Condition LC1 D+L 1.0 S Sump is dry or flooded LC2 D + L+T 1.0 S Sump is dry or flooded LC3 D + L+T + E 1.33S Sump is dry or flooded LC4 D + L + T + E' 1.5 S or Y Sump is dry or flooded LC5 D+L+T+P+J+R Y Sump is dry or flooded D is the dead weight load component.

L is the live loads.

Ldp is the differential pressure live load across a debris covered strainer.

Ldeb is the debris weight live load. The live load of the strainer includes the weight of the debris, which accumulates on the strainer during accident conditions. The debris is considered captured by the strainer and is, therefore, active during a seismic event.

T is the thermal load. There are no thermal expansion loads since the strainers are basically free to expand without restraint due to sufficient fabrication tolerances which allow for thermal growth.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 37 of 78 E is the operating basis earthquake load.

E, is the operating basis earthquake including underwater earthquake effects.

E' is the safe shutdown load.

E'w is the safe shutdown earthquake including underwater earthquake effects.

P is the differential pressure loads where they occur. The strainer is designed for a maximum differential pressure that is applicable in all load combinations such that it is considered a live load.

J is the jet impingement force where it occurs. There are no jet impingement loads applied to the strainer components. There are no high energy line breaks postulated in this area of containment.

R is the pipe rupture reactions where it occurs. There are no pipe rupture reactions applied to the strainer.

S is the required section strength based on the elastic design methods and the allowable stresses.

Y is the yield strength of material.

The following two load combinations are code checked to envelope the above five load combinations for the analysis of the assembly using the GSTRUDL model.

Load Combination Allowable Applicable Environmental Condition Norm: D + Ldeb + Ldp 1.0 S These are the LC2 loads with submerged strainer at maximum fluid temperature vs LC2 allowables.

SSE: D + Ldeb + Ldp + Ew 1.33 S These are the LC4 loads with submerged Strainer at maximum fluid temperature vs LC3 allowables.

The material properties for stainless steel materials at elevated temperatures are taken from ASME Section III, Appendix 1, 1989 Edition.

In general, applicable design and analysis methods and equations from B31.1-1973 are used for the strainer components. A proper allowable stress is determined based on the code most applicable to the type of component.

The fabricated non pressure components that provide load bearing support within the assembly are designed using allowable stresses in accordance with AISC 9t edition.

Since AISC "Steel Construction Manual" was developed for carbon steels, ANSI/AISC-N690 was used for guidance regarding design of austenitic steels to ensure the analysis was conservative. The stainless steel members in compression were checked against allowables from ANSI/AISC-N690.

The B31.1 Code does not provide design requirements for perforated plates. Therefore, for the perforated plates, the equations from Appendix A Article A-8000 of the ASME B&PV Code,Section III, 1989 Edition were used to calculate the perforated plate stresses. The maximum principal stresses were calculated and compared to the allowable limits, S, as given in Appendix A of the B31.1 Code.

The interaction ratios for the components in the models are provided in Table 3.k-2. The results of the calculation indicate the interaction ratios for the strainer assembly components are below

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 38 of 78 1.0, and the strainers meet the acceptance criteria for all applicable loadings.

Table 3.k-2 Interaction Ratios for strainer Assembly Components Strainer Component Normal SSE Disk Rim Rivets 0.05 0.41 Gap Rivets 0.08 0.07 Mounting Bolt Connection 0.05 0.14 Angle Iron Tracks 0.13 0.70 Alternate Angle Iron to Angle Iron Track Weld 0.09 0.77 Alternate Angle Iron Stiffener Welds 0.08 0.19 Angle Track Expansion Anchors (envelopes alternate clip angle 0.09 0.82 and cross anchor bolts)

Cross Beam Assembly 0.12 0.74 Module to Module Sleeve Banding 0.35 0.88 End Cover Assembly 0.83 0.66 End Cover Anchor Bolts 0.74 0.92 The structural qualification of the piping and supports for the piping were evaluated via a separate calculation. The piping is evaluated in accordance with ANSI B31.1 Power Piping 1973 Edition. Basic material allowable stresses are taken from Appendix A of B31.1. Load combinations are as follows:

Load Condition Stress Combination Allowable Stress Normal (Sustained) P + DW 1.0 Sh Thermal (Displacement) T 1.0 SA Upset (Occasional) P + DW + OBE 1.2 S, Faulted (Occasional) P + DW + DBE (SSE) 1.0 SY Sh is the basic material allowable stress at temperature for normal service condition, T=283°F.

S, is the basic material allowable stress at ambient temperature, t=700 F.

SA is the allowable code stress range, (1.25 x So + 0.25 x Sh).

SY is the yield stress.

Since specific detailed guidance is not provided in B31.1 for flanges, the bolted flange connections were evaluated in accordance with the guidelines of ASME Section III, Appendix L.

The allowable stresses on the piping support components are based on the 1989 AISC Specification included in the 9 th Edition but utilizing the more conservative compression allowables for stainless steel provided in ANSI/AISC-N-6190. The load combinations are as follows:

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 39 of 78 Load Condition Load Combination Allowable Stress Normal DW+T 1.0 AISC Upset DW + T + OBE 1.33 AISC Faulted DW + T + DBE (SSE) 1.33 AISC The interaction ratios for the piping, flanges, and supports in the models are provided in Table 3.k-3. The results of the calculation indicate the interaction ratios for the strainer piping and supports are below 1.0, and the strainers meet the acceptance criteria for all applicable loadings.

Table 3.k-3 Interaction Ratios for Piping, Flanges, and Supports Item Maximum of Normal, Upset, or Faulted Pipe segment 1 0.61 Pipe segment 2 0.77 Pipe segment 3 0.32 12" Pipe Support 0.94 18" Pipe Support 0.87 14" Pipe Support 0.65 Integral Welded Attachments Segment 3 0.74 Integral Welded Attachments Segment 1 0.86 Concrete for Anchors 0.91 Normal Upset Faulted Flange Bolting 18" 0.76 0.90 0.73 Flange Bolting 14" 0.47 0.49 0.42 Flange Bolting 14"s 0.18 0.20 0.17 Flange Bolting 12" 0.45 0.69 0.53 Flange Bending 18" 0.63 0.75 0.61 Flange Bending 14" 0.52 0.53 0.45 Flange Bending 14"s 0.12 0.13 0.11 Flange Bending 12" 0.64 0.99 0.76 Flange Weld to Pipe 18" 0.57 0.60 0.61 Flange Weld to Pipe 14" 0.43 0.46 0.48 Flange Weld to Pipe 14"s 0.05 0.06 0.06 Flange Weld to Pipe 12" 0.36 0.41 0.41

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 40 of 78 Topic 3.1: Upstream Effects FPL Response In the September 1 response it was noted that the refueling canal drains required further evaluation to determine if they constituted potential choke points. Subsequent to the September 1 submittal, a walkdown was conducted in the Turkey Point Unit 4 containment specifically to evaluate ECCS recirculation flow paths. The walkdown utilized the guidance in Nuclear Energy Institute (NEI) Report 02-01, NEI Report 04-07 and the staff's SE of NEI 04-07.

[RAI 38] The information obtained during the walkdown confirmed that the only potential choke points are the fuel transfer canal drain covers at the bottom of the refueling canal. The drain covers are intended to prevent items from falling into the drains during refueling operations.

There are two drain lines in the refueling cavity. These drains are six inches in diameter and as such any debris that would reach the lower cavity is expected to drain through this large line provided the covers are removed. Therefore, these potential choke points have been eliminated by updating the containment closeout procedure to ensure that the drain covers are removed prior to restart. The procedure changes are described in the response to NRC Topic 3.i, Debris Source Term.

Other specific NEI and NRC concerns that were addressed in the walkdown are itemized below:

Choke points will not be created by debris accumulating on access barriers (fences and/or gates).

Choke points will not be created by debris accumulation in narrow hallways or passages.

No curbs or ledges were observed within the recirculation flow paths. At the upper elevations, concrete slabs smoothly transition to grating or open space without any contiguous curbs.

No potential chokepoints were observed at upper elevations, including floor grates, which would be expected to retain fluid from reaching the containment floor.

" The containment floor was surveyed for chokepoints formed by equipment, components and other obstructions. While some debris hold up may occur, it will not prevent water from reaching the sump strainers.

During refueling outage PT4-23 (fall 2006), subsequent to the choke point walkdown, debris interceptors were installed in the containment to limit the quantity of debris that could reach the sump strainers and screens. The debris interceptors were installed in five separate locations that limit debris transport from the inside to the outside of the biowall. The debris interceptors are designed to have an open flow channel above them, even at the minimum sump pool levels.

This assures that water is not prevented from reaching the sumps and therefore, no choke points are created by installation of the debris interceptors regardless of debris accumulation.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 41 of 78 Topic 3.m: Downstream Effects - Components and Systems FPL Response

[RAI 31] Component downstream analyses have been completed and use the methodologies of WCAP-16406-P Revision 1 (WCAP-16406-P, "Evaluation of Downstream Sump Debris Effects in Support of GSI-1 91", Revision 1, August 2007). The Turkey Point Unit 4 responses to the NRC staff's Limits and Conditions related to the staff review of WCAP 16406-P are provided in , Enclosure 1.

The analysis of downstream effects at PTN-4 primarily follows that set forth in WCAP-16406-P, Revision 1. A summary of the application of those methods is provided below with a summary and conclusions of the downstream effects calculations performed. Any exceptions or deviations from the NRC-approved methodology are noted below. The methodology, summary, and conclusions are provided as related to downstream component blockage and wearing, the subjects addressed by Topic 3.m.

Blockage/Pluqqing of ECCS and CSS Flowpaths and Components GL 2004-02 Requested Information Item 2(d)(v) addresses the potential for blockage of flow restrictions in the ECCS and CSS flowpaths downstream of the sump screen, while item 2(d)(vi) refers to plugging of downstream components due to long-term post-accident recirculation. The difference in requirements is that blockage refers to the instantaneous blockage of flowpath components due to the maximum debris size that passes the recirculation sump filtration system, as compared to plugging which is due to the settling of any size debris in downstream components long-term. The evaluations performed for downstream components at PTN-4 considered both blockage and plugging as required for a particular component type, although the terminology was used interchangeably in the evaluations. The following summarizes the evaluation of downstream components that was performed at PTN-4, using the blockage and plugging terminology consistent with the GL 2004-02 Requested Information Item.

As part of the resolution for GSI-191, the existing sump screen system was removed and replaced with PCI Sure-Flow stainless steel modular sump strainers. Following the installation, the nominal strainer opening size has been reduced from a 1/4 in. nominal square opening (diagonal dimension of 0.354 in.) to a nominal round opening of 0.095 in. diameter. The new strainer system is described in the response to NRC Topic 3.j, Screen Modification Package.

GL 2004-02 Requested Information Item 2(d)(v) requires that the licensee state "the basis for concluding that adverse gaps or breaches are not present on the screen surface." The inspection procedure to ensure that adverse gaps or breaches are not present on the screen surface is described in NRC Topic 3.i, Debris Source Term.

WCAP-16406-P Section 5.5 provides assumed particle dimensions for recirculation debris ingestion based on sump screen hole dimensions. Rather than the WCAP-1 6406-P suggested asymmetrical dimensions, the PTN-4 downstream components were analyzed for blockage based on a maximum 0.125 in. spherical particle. The actual maximum spherical size particulate debris that can pass through the strainer system and into the ECCS and CSS recirculation flowpaths is documented as 0.103 in.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 42 of 78 All ECCS and CSS downstream components that see active flow during recirculation (including control valves, orifices, flow elements, containment spray nozzles, and heat exchanger tubes) were analyzed for blockage due to this maximum particulate debris size. All flowpaths that could see recirculation flow per the plant design basis were considered. In accordance with the WCAP-16406-P methodology, the minimum clearance dimension within the component was checked to ensure it is larger than 0.125 in. The results of that analysis are summarized below.

Where necessary, low-flow components and piping were analyzed for plugging due to settling, as described below. Finally, static instrument sensing lines, relief valves, and check valves required to close during recirculation were analyzed for potential debris interference as discussed below.

Control Valves WCAP-1 6406-P Section 7.3 lists possible failure modes for valve types that can be expected in the recirculation flowpaths. The SER Section 3.2.5 notes that this list is comprehensive and acceptable for general use, but notes that it is not all-inclusive. In accordance with the SER recommendation, all valves in all possible recirculation flowpaths were considered and found to be of standard types as listed in WCAP-16406-P Section 7.3. Every recirculation control valve was compared to the general criteria in WCAP-16406-P Table 8.2-3; any valve requiring further evaluation for plugging per WCAP-1 6406-P Section 8.2.4 was identified, including all throttled valves (globe, needle, and butterfly) and globe and check valves less than 1.5 in. nominally.

The minimum flow clearance through these valves was determined from vendor drawings, and for any throttled valves based on the subcomponent dimensions and lift settings. This minimum flow clearance was compared to the cross-sectional area of a 0.125 in. sphere to ensure that blockage would not occur. The WCAP-16406-P does not require analyzing valves for debris settling. In general, control valves see higher flow velocities than the pipe leading to them, and therefore the valves were not checked for debris settling where the pipe velocity was sufficient (see below).

Root valves and other valves in static instrument sensing lines were analyzed with those instrument lines as discussed below. Relief valves were analyzed for interference as discussed below. Check valves that open but then may require closing during recirculation were also checked for possible interference issues as identified in WCAP-1 6406-P Table 7.3-1. This could occur where low flow causes debris settling around the valve seat while open, and then the debris prevents proper closure when the check valve should close. In accordance with WCAP-16406-P guidance, a flow velocity of 0.42 ft/s was considered sufficient to prevent debris settling and thereby preclude interference with proper valve closure. The flow velocity for settling was determined from the larger flow area of the nominal pipe size leading to the valve.

Because all flow clearances were sufficiently large to preclude blocking and flow velocities are fast enough to preclude plugging and interference, all control valves at PTN-4 were found to be acceptable with respect to blockage and plugging during recirculation. Again, relief valves and instrumentation root valves were addressed separately as discussed below.

Relief Valves Relief valves on the recirculation flow paths were also considered for interference issues. Here, the maximum pressure in the primary line during recirculation operation was conservatively determined based on maximum containment pressure, pump shut-off heads, and no line losses.

Where the relief valve set pressure was higher than this pressure, it was determined not to open

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 43 of 78 during recirculation and therefore debris interference was not an issue. If a relief valve could potentially open, then blockage and the effects of debris interference with closure would be considered. This was not applicable to PTN-4 because all relief valves were found not to be subject to opening during recirculation.

Heat Exchangers All heat exchangers that see recirculation flow were also considered for blockage and plugging.

This included both the major heat exchangers as well as those in the pump seal subsystems that see debris-laden flow. In accordance with WCAP-16406-P Section 8.3.1, the inner diameter of tubes was compared to the maximum assumed particle size. In accordance with the SER Section 3.2.6, the heat exchanger tubes were also checked for plugging due to settling within the tubes, by comparing the minimum average flow velocity in the tubes to the WCAP-16406-P settling velocity (0.42 ft/s). All heat exchangers were found to be acceptable with respect to blockage and plugging.

Orifices, Flow Elements, Spray Nozzles All orifices, flow elements, and spray nozzles in the ECCS and CSS recirculation flowpaths were checked for blockage. In accordance with WCAP-16406-P Section 8.4, the minimum flow clearance of each was compared to the maximum assumed particle size. All orifices, flow elements, and spray nozzles were found to be acceptable with respect to blockage. The WCAP-16406-P does not suggest analyzing orifices, flow elements, and spray nozzles for debris settling. In general, orifices, flow elements, and spray nozzles see higher flow velocities than the pipe leading to them, and therefore were not checked for debris settling where the pipe velocity was sufficient (see below).

Instrumentation Lines All instrumentation branch lines on the ECCS and CSS recirculation flow paths were analyzed for blockage and plugging. WCAP-1 6406-P Section 8.6 generically justifies static flow (water-solid) sensing lines on the basis of minimum expected flow velocities compared to debris settling velocities. However, the PTN-4 review of instrument lines was plant-specific. First, the actual orientation of each instrument line was determined. Water-solid sensing lines oriented horizontally or above are considered not susceptible to debris settling into the lines. For any instrument lines oriented below horizontal, the actual minimum flow velocity through the header line at the point of the branch was determined. This velocity was compared to the WCAP-16406-P bounding settling velocity of 0.42 ft/s, as opposed to the lower debris-specific settling velocities listed in WCAP-16406-P Table 8.6-1. This approach is consistent with the recommendation of the SER to WCAP-16406-P. All sensing lines were found to be acceptable with respect to plugging due to debris settling. Because the lines are water-solid, they are not susceptible to direct blockage due to large debris flowing into the lines.

Any sampling lines on the ECCS and CSS recirculation flowpaths that are required by plant procedure to be used post-accident were also considered. The sampling lines were analyzed as any other flow path when opened to take a sample: blockage and plugging of the tubing and each component was considered. The orientation of each sampling line was also checked, like an instrument line, to ensure it was not susceptible to settling of debris into the line when water-solid. All sampling lines were found to be acceptable.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 44 of 78 Per the guidance of WCAP-16406-P Section 8.6.10, the PTN-3 RVLIS design was compared to the generic designs reviewed and deemed acceptable by the WCAP-16406-P. The plant design was found to be consistent, and therefore it is expected to be acceptable with regards to recirculation operation. However, the SER Section 3.2.6 notes that "evaluation of specific RVLIS design and operation is outside the scope of this SE and should be performed in the context of a licensee's reactor fuel and vessel evaluations." This is discussed in Attachment 2, , L&C19.

Pip-in The WCAP-16406-P does not require evaluation of piping for potential blockage or plugging.

However, in accordance with the SER Section 3.2.6, ECCS and CSS system piping was evaluated for potential plugging due to debris settling. As stated above, control valves in the ECCS and CSS lines were checked to ensure debris settling does not interfere with valve movement. The valves were checked using the flow area of the pipe in which the valves are installed. Therefore, the evaluation for control valves was used to validate that settling will not occur in the system pipes generally. It was verified that the analysis of control valves included valves in all lines in the ECCS and CSS used for recirculation, so that local flow velocities of the various line sizes and flow rates in the PTN-4 ECCS and CSS were all considered. As with other settling reviews, the minimum expected system flow rates in each line were used to minimize the flow velocity. The average velocity was determined for each pipe size based on the specific flow rate in that line and compared to the bounding settling velocity of 0.42 ft/s. All valve locations, and therefore all lines, were found acceptable with respect to plugging. Piping was not considered specifically for blockage because flow restrictions in the lines are more limiting with respect to minimum flow clearance.

Reactor Internals and Fuel Blockage WCAP-16406-P Section 9 provides general guidance concerning the evaluation of the reactor internals and fuel assembly for potential debris blockage. The SER Section 3.2.7 states that this guidance is general in nature and provides a starting point for evaluation, while more detailed methodology is provided by WCAP-16793-NP and the NRC's SE thereto. The evaluation that was performed is discussed in Topic 3.n Downstream Effects - Fuel and Vessel.

Pumps The WCAP-16406-P addresses two concerns with regard to debris blockage or plugging. First, Section 7.2 states that debris in the pumped flow has the potential of blocking the seal injection flow path, or limiting the performance of the seal components due to debris buildup in bellows and springs. A review of the PTN-4 ECCS and CSS pump seals in accordance with the WCAP-16406-P methodology determined that the HHSI and LHSI pumps have seal injection arrangements using only recirculated seal cavity fluid. This precludes blockage of the seal injection flow path and the injection of debris laden post-LOCA fluids into the seal cavity chamber so that sump debris will not enter the seal chamber and will not impact the operation of seal internal components. The CS pump seals previously used a seal cooling system relying on process water with a cyclone separator. Consistent with WCAP-1 6406-P guidance as augmented by the SER Section 3.2.5, a plant-specific review of pump operation determined that a water seal system that utilizes recirculated seal cavity fluid was preferable to the use of injected process fluid and was subsequently installed. Further, the SER Section 3.2.6 disagreed with a WCAP-1 6406-P statement that seal failure due to debris ingestion is

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 45 of 78 considered unlikely, because the WCAP-1 6406-P statement was founded upon only a single test. However, since the PTN-4 pump seals use only recirculated seal cavity fluid in the spring and bellow areas of the seal that were identified as a concern, the SER Section 4.0 limitation expressing concern with this WCAP-16406-P statement is not applicable. Otherwise, the SER endorses the mechanical seal analysis recommended by the WCAP-1 6406-P with respect to debris interference.

WCAP-16406-P Section 7.2.3 further states that running clearances of 0.010 inch on the diameter could be clogged when exposed to pumpage with 920 PPM and higher debris concentration from failed containment coatings. It states that as a consequence of the clogging, a packing type wear pattern was observed on the rotating surface. This clogging of running clearances creates asymmetrical wear, but was not identified as having a negative impact on pump performance aside from increased wearing (which was considered as discussed below).

Also, the WCAP-16406-P states that shaft seizure due to packing debris build-up is unlikely.

The SER Section 3.2.5 also endorses this WCAP-1 6406-P guidance.

No other areas of concern for debris plugging or blockage within ECCS and CSS pumps were identified by either the WCAP-16406-P or the SER. Wear analysis of the pumps due to debris-laden water in close-tolerance running clearances, including packing type debris build-up, was considered as discussed below.

Conclusion (Blockage/Plugginq)

As summarized above, analysis of all lines and components in the recirculation flowpaths at PTN-4 determined that there is no potential for either debris blockage or long-term plugging, which would threaten adequate core or containment cooling.

Wearing of ECCS and CSS Recirculation Flowpath Components GL 2004-02 Requested Information Item 2(d)(vi) concerns excessive wear of ECCS and CSS recirculation components due to extended post-accident operation with debris-laden fluids. All ECCS and CSS downstream components that see active flow during recirculation (including pumps, control valves, orifices, flow elements, containment spray nozzles, piping, and heat exchanger tubes) were analyzed for wear due to an analytically determined bounding debris load for the full recirculation mission time. All flowpaths that could see recirculation flow per the plant design basis were considered.

The evaluation of long-term wearing of ECCS and CSS recirculation components was performed for a 30-day period following initiation of recirculation post-LOCA. The 30 days period is consistent with the SE of NEI 04-07, WCAP-16406-P, and the PTN-4 UFSAR. All components were analyzed for a full 30 days of operation, unless plant specific procedures and system configurations established a shorter maximum duration of operation. WCAP-16406-P Section 4.2 provides guidance for reducing mission times outside of plant licensing basis for components that are predicted to fail due to recirculation wear. However, consistent with SER Section 3.2.2, only plant-specific component mission time input in accordance with design and licensing basis was utilized for any deviation from a 30 day mission time, and only existing design basis hot-leg recirculation methods were credited. The following summarizes the evaluation of downstream components that was performed at PTN-4.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 46 of 78 Debris Concentration and Size Distribution The PTN-4 debris concentration and size distribution for downstream effects wear was calculated based upon the methodology provided by WCAP-16406-P, except as otherwise noted.

The total debris load was determined for a bounding LBLOCA in accordance with NEI 04-07. A minimum sump water volume for recirculation was determined for a SBLOCA to maximize the debris concentration in containment. All debris was assumed to be in the sump pool and eroded (to the extent it would be after 30 days) at the start of recirculation. Only RMI and fiberglass insulation (Nukon) were categorized into fines and debris too large to pass the strainer (e.g., small, large, and intact); this categorization was based on industry experimental data. All other debris was assumed to be entirely fines, capable of passing the strainer unless its final eroded size is larger than 0.125 in. based on a detailed size distribution described below (see above regarding debris size assumed to pass through the strainer). Based on these inputs, the initial debris concentration at the start of recirculation was calculated.

The debris concentration was then depleted over the recirculation mission time in accordance with the methodology presented in WCAP-16406-P Section 5. For the purposes of debris depletion, only latent particulate debris, Cal-Sil, and unqualified coatings were size distributed.

The Cal-Sil and latent debris size distributions were calculated from industry data. The distributions were calculated based on empirical data and for the specific debris types at PTN-4, but the distribution was not based on plant-specific testing. For unqualified coatings, the size/mass distributions of the WCAP-16406-P were used. Qualified coatings were not taken to fail entirely to 10 micron spherical particulate, which is consistent with the WCAP-16406-P as amended by the SER Section 3.2.15 since a fibrous thin-bed was not substantiated. While SER Section 3.2.15 states that plant-specific analysis should be performed to size the coating debris, 50 microns was assumed as the coating debris size for qualified coatings based on the upper size limit documented in NEI 04-07 Appendix A.

The particulate debris distribution (in addition to reducing the amount of debris assumed to initially pass the strainer, as discussed above) was utilized to deplete the particulate over time due to settling in the reactor vessel. Consistent with the WCAP-1 6406-P guidance, the particulate debris size subject to vessel depletion was calculated for each debris type based on force balance methods using a maximum core flow rate (cold leg recirculation for a hot leg break) to minimize debris settling. All particulate debris was assumed to be spherical for determination of settling size. Debris smaller than the calculated size for a given type was taken to remain in solution throughout recirculation. Two cases were analyzed for particulate depletion: a high vessel flow rate that would occur if low-head safety injection were used during long-term recirculation was used to calculate particulate depletion for input into the LHSI pump wear analysis (discussed below); a lower vessel flow rate that would occur if high-head safety injection were used to calculate particulate depletion for the HHSI pump wear analysis. The depletion coefficient for depletable particulate was calculated according to WCAP-16406-P Section 5.8 based on plant specific inputs for conditions to minimize depletion.

Two deviations were taken from the WCAP-16406-P approach with respect to fibrous debris depletion. First, all fiber was assumed to be depletable and no fibrous debris is too small as to remain in solution. Second, in lieu of the 95% fiber capture efficiency for the strainer suggested by WCAP-16406-P, or an empirically determined fiber capture efficiency as stated by the SER Section 3.2.17, the strainer capture efficiency was calculated based on an equation originally

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 47 of 78 found in Draft Rev. 0 of the WCAP-16406-P. This resulted in a conservative strainer capture efficiency of only 44.89%. However, in all cases, the depletion coefficient used for the fibrous debris was the SER and WCAP-16406-P agreed conservative value of (A = 0.07/hr or half-life of 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months ).

For analysis of abrasive wear (pump moving parts), the debris was further categorized based on the size distribution of particulate debris as erosive versus abrasive debris. All fibrous debris was assumed to be large enough to be abrasive. For particulate debris, a modification to the WCAP-16406-P methodology was used to refine the distribution of abrasive versus erosive debris. While the WCAP-16406-P considers 50 microns to be the constant threshold for abrasive debris (which is equal to 2.5X the wear ring gap of the hypothetical pump considered therein), PTN-4 used 2.5X the actual wear ring gap at any given time to define the threshold for abrasive-sized particulate. In other words, as the wear ring gap opens, the abrasive debris is reduced. However, the amount of abrasive debris that was reduced was then taken to contribute to erosive wear.

The calculation of erosive wear considered the effect of small particulates. Credit was taken for reduced erosive wear in accordance with the Hutchings Summation methodology presented in WCAP-16406-P Appendix F. The Hutchings Summation was conservatively calculated based upon the particulate distribution discussed above.

The time-dependent debris concentration calculated according to the above methodology was then utilized for the calculation of wear on all ECCS and CSS recirculation components. The calculation of wear for each type of component, including the effect of the wear on component performance, is summarized below.

Pumps The ECCS and CSS pumps were analyzed for wear in general accordance with the methodology presented in Sections 7.2 and 8.1 of WCAP-16406-P. The depleting abrasive and erosive debris concentrations as discussed above were a primary input of the analysis.

For all pumps, the wear rings were assumed to have a starting gap equal to the midpoint of the wear ring acceptability range prescribed by the pump manufacturer. All wear rates were calculated specifically for each PTN-4 pump based on actual pump dimensions, materials, and operating speeds, and the debris concentration at a given time (the generic wear rates determined in the WCAP-1 6406-P were not applied). The wear analysis considered the combined effect of abrasive wear due to larger debris and debris packing, and erosive wear due to smaller debris (as defined above). The wear rate at each hour was numerically integrated to determine the total material wear following the recirculation mission time.

Pump wear analysis considered the combined effect of abrasive wear due to larger debris, and erosive wear due to smaller debris (as defined above). In accordance with WCAP-16406-P Appendix Q and the SER Section 3.2.23, a penalty was applied to the debris concentration wear rate because the total concentration of abrasive particulates and fibrous debris exceeds 720 PPM at the start of recirculation. A conservative deviation from the WCAP-1 6406-P approach was made in that all debris large enough to be abrasive was considered to wear equally, as opposed to the WCAP-16406-P approach of taking coatings as softer. In accordance with the SER Section 3.2.23, the ratio of abrasive to fibrous debris was verified as less than 5 to 1.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 48 of 78 The single-stage CS and LHSI pumps were analyzed for symmetrical wearing of the inboard and outboard wear rings (no "suction multiplier" was applied). Packing-type wear was not applied to the single-stage pumps, in accordance with the WCAP-1 6406-P. The total material wear after the recirculation mission time was then used to determine the final wear rings gaps for the suction and discharge side. The change in gap was used to evaluate the impact on pump hydraulic performance per the approach of WCAP-16406-P Section 8.1. The discharge head following 30 days of wear was determined to be acceptable for the CS and LHSI pumps.

Per WCAP-1 6406-P Section 8.1.4, no vibration analysis was performed for single-stage pumps.

The mechanical seals were evaluated for debris interference concerns as discussed above.

The multistage HHSI pumps were also analyzed for concurrent abrasive and erosive wear.

Here, however, packing-type abrasive wear was found to be more limiting than free-flowing abrasive wear. Therefore, the HHSI pumps were analyzed according to the Archard wear model presented by WCAP-16406-P Appendix 0. For inputs into the Archard wear equation, the pressure drop across the wear rings was calculated for the actual PTN-4 pumps based on actual pump head at the expected recirculation flow rate, actual pump (subcomponent) dimensions were used, the eccentricity was assumed maximum, and the wear coefficient was taken as the bounding of the range provided by the WCAP-1 6406-P. The packing-type abrasive wear was assumed to occur immediately upon pump recirculation initiation, and to continue until a wear ring gap of 50 mils was attained, at which point the packing at each discharge-side wear ring was assumed to expel, in accordance with the WCAP-1 6406-P methodology. If the expulsion of the packing occurred prior to the end of the analyzed mission time, the wear of the discharge side wear ring was analyzed for continuing abrasive and erosive wear (free-flow) until the end of the mission time. The suction-side wear rings were taken to wear asymmetrically as a result of the packing-wear on the discharge side, and were analyzed using a suction multiplier of 0.205, per PWR Owners Group document OG-07-510.

The final wear ring gap of the suction and discharge sides after the recirculation mission time was then utilized to perform hydraulic and vibration analyses of the multistage pumps. Based on the pumps' starting discharge head (per IST history) and the acceptable range, the discharge head following 30 days of wear was determined to be acceptable for the HHSI pumps. The shaft centering load (Lomakin effect) method in WCAP-16406-P Appendix 0 was used to evaluate the HHSI pumps for vibration failure due to wear. In order to maximize vibration, the centering load was maximized by assuming a minimum friction coefficient, maximum eccentricity, and also maximized in relation to Cd (diametric clearance) and f (friction coefficient).

Again, the wear ring pressure drop was calculated based on actual pump head at the expected recirculation flow rate. The resulting shaft stiffness based on the centering load and wear ring gap was calculated using the suction and discharge side wear ring gaps following 30 days of wear. The stiffness was compared with the stiffness that would result from increasing the suction and discharge side wear ring gaps to 2.5X the manufacturer's allowable wear ring gap (symmetric wear acceptability criterion from WCAP-16406-P). Plant-specific rotor dynamic analysis determined that the HHSI pumps are acceptable for wear ring gaps 2.5X the manufacturer's new ring clearance. The shaft stiffness of the HHSI pumps under asymmetric wear was found to be greater than this acceptance criteria and, therefore, the HHSI pumps were determined to be acceptable with respect to vibration. The mechanical seals were evaluated for debris interference concerns as discussed above.

Non-mechanistic failure of an ECCS or CSS pump seal is considered as a single-failure in the plant design basis and is acceptable. The WCAP-1 6406-P attempts to justify failure of the seals due to recirculation debris, which is a potential common-mode failure. The pump seals at PTN-

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 49 of 78 4 have been evaluated as not susceptible to failure by debris-laden water because they recirculate only seal cavity fluids. Therefore the only potential failure that must be considered is an assumed single failure of the pump seal, which again is part of the existing design basis of the plant (bounded by a moderate energy line break in the pump room). The potential for debris to cause an increased leakage flow through the disaster bushing following that single-failure is evaluated below.

A 50 gpm seal leak has been evaluated for PTN-4 (ref. DBD 5610-050-DB-002, Residual Heat Removal System, section 2.3.12). Calculations have been performed on other multistage pumps which has demonstrated the leakage to be less than 50 gpm and that the wear for the 30 minute duration of the leak is relatively minor (ref Westinghouse calculation CN-SEE-I-08-18, rev 0, Seabrook Unit 1 Mechanical Seal Evaluation for ECCS and CS Pumps, page 38). At Turkey Point Unit 4 the rooms containing the containment spray pumps, the high head safety injection pumps, and the RHR pumps are not habitable following a LOCA.

Based on the calculations for similar multistage pumps, the short duration of the leak, and the existing dose rates in the area, any increased leakage flow through the disaster bushing is determined to be acceptable.

The WCAP-16406-P criteria were based on performance of each individual component.

However, the SER further identifies the need to check the entire ECCS and CSS systems in an integrated approach to ensure that the combination of pump and system component wear would not threaten adequate core cooling, considering increased system flow and decreased pump performance due to wear. An overall system performance assessment determined that these systems remain capable of fulfilling their required safety related functions in the presence of debris-laden fluid following a LBLOCA at the PTN-4 Nuclear Power Plant.

Heat Exchanqers In accordance with WCAP-16406-P Section 8.3, the recirculation heat exchangers (both the primary system heat exchangers, and the pump seal heat exchangers) were analyzed for erosive wear. The standard erosive wear formulas in the WCAP-16406-P, adjusted for the actual material hardness and adjusted via the Hutchings Summation described above, were used with the PTN-4 heat exchanger dimensions and maximum recirculation flow rates to predict the maximum erosive wear over 30 days of recirculation. All heat exchangers were found to have sufficient wall thickness margin for a maximum possible differential pressure across the heat exchanger tubes.

Valves The WCAP-16406-P guidance is that manual throttle valves should be analyzed for the effects of erosive wear. It is assumed that a manually throttled valve as defined in WCAP-16406-P is one that requires an operator to locally throttle the valve (at the valve location) as opposed to a remote manual valve that can be adjusted from the control room. It is further assumed that a remote manual valve can be adjusted from the control room to compensate for an increase in flow area due to erosive wear. Therefore, erosion wear analyses were not performed for remote manual valves. Since there are no locally throttled ECCS or CSS valves at PTN-4, no wear analysis was required to assess downstream effects on valves in the recirculation paths.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 50 of 78 Orifices, Flow Elements, Spray Nozzles All orifices, flow elements, and the containment spray nozzles in the PTN-4 recirculation flowpaths were analyzed for the effects of erosive wear upon performance. The standard erosive wear formulas in the WCAP-1 6406-P, adjusted for the actual material hardness and adjusted via the Hutchings Summation described above, were used with the PTN-4 component dimensions and maximum recirculation flow rates to predict the maximum erosive wear over 30 days of recirculation. The total material wear was used with the WCAP-1 6406-P formulas to predict the maximum change in flow rate due to the erosive wear of an orifice, flow element or spray nozzle. A conservative deviation was made from the WCAP-1 6406-P guidance in that a 3% limit for change in flow was applied for all orifices, flow elements, and spray nozzles.

Furthermore, all orifices were assumed to be sharp-edged, which creates a higher change in flow rate for a given amount of wear. Based on the analysis, all PTN-4 orifices, flow elements, and the containment spray nozzles were found to be acceptable. Only the CSS spray nozzles were found to exceed the 3% for negligible change in flow, but a conservative evaluation of the impact on system performance (including pump NPSH available) determined that the change in flow was acceptable.

The SER to WCAP-1 6406-P requires that licensees perform a piping wear evaluation. The SER Section 3.2.6 does not detail the scope of the assessment, but since it refers to the need for a vibration assessment if areas of high piping wear are identified, it is taken to mean that piping should be checked for wall-thinning (structural) purposes like the heat exchanger tubes. With regard to pipe wall erosion, WCAP-16406-P states "There is no expected impact on ECCS and CSS piping based on downstream sump debris... since the pipe wall thickness is sufficiently larger than expected wear." To validate this assumption, the material wear of the bounding orifice in the ECCS and CSS was compared to the pipe wall thicknesses used in the systems.

This conservative material wear exceeds that applicable to piping because the flow velocities in piping are much less compared to the bounding orifice velocity (the wear rate is proportional to the flow velocity squared), while the material of construction is the same. The material wear was found to be insignificant compared to the pipe wall thick-nesses used in the ECCS and CSS. Therefore, all recirculation pipes were determined to have sufficient margin, and the erosion was considered so slight as to not require vibration analysis.

Conclusion (Wear)

No other components required erosive wear analysis. As summarized above, analysis of all lines and components in the recirculation flowpaths at PTN-4 determined that the components are expected to wear acceptably based on the WCAP-1 6406-P criteria for 30 days of recirculation.

The WCAP criteria were based on the performance of each individual component. The SER further identifies the need to check the ECCS and CSS systems in an integrated approach to ensure that the combination of pump and system component wear would not threaten adequate core cooling, considering increased system flow and decreased pump efficiency due to wear.

Based on an overall system performance assessment, the ECCS and CSS remain capable of fulfilling their required safety related functions in the presence of debris-laden fluid following a LBLOCA at the PTN-4 Nuclear Power Plant.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 51 of 78 Summary of Desiqn or Operational Changes Additionally, NRC Content Guide Topic 3.m requests that licensees "Provide a summary of design or operational changes made as a result of downstream evaluations." The following plant design changes made in response to GSI-1 91 contribute to the resolution of downstream effects:

As previously discussed, in response to downstream blockage concerns the new strainer system was designed with nominal strainer opening holes of 0.095 in. diameter, reduced from the previous 1/4 in. nominal square opening (diagonal dimension of 0.354 in.). The new strainer system is described in the response to NRC Topic 3.j, Screen Modification Package. The actual maximum spherical size particulate debris that can pass through the new strainer system and into the ECCS and CSS recirculation flowpaths is documented as 0.103 in.

A modification was completed to remove the cyclone separators on the seal water lines for the containment spray pumps and replace the mechanical seals with an API plan 23 design.

With this design seal water in a closed loop is pumped to a heat exchanger and back to the mechanical seal. The mechanical seal functions as a pump. The heat exchanger was repositioned above the mechanical seal to allow thermal recirculation to assist the pumping action of the mechanical seal.

Existing insulation on the RCPs in containment was replaced with RMI, which reduced particulate and fibrous insulation in the recirculation fluid.

The insulation on the Pressurizer Relief Tank was permanently removed. This reduced the quantity of Cal-sil insulation that can be generated during a LOCA and thus resulted in decreased wearing of downstream components.

The only operational change made related to downstream effects is that inspection requirements were updated for the new strainer system. Inspection of the strainer system requires verification of maximum strainer equipment gaps to meet new specifications to maintain debris bypass size limits, and inspection now includes new strainer system piping in addition to the strainer filtration surface. The inspection procedure to ensure that adverse gaps or breaches are not present on the screen surface is described in NRC Topic 3.i, Debris Source Term.

No other design or operational changes were required in response to ECCS and CSS downstream effects evaluations.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 52 of 78 Topic 3.n: Downstream Effects - Fuel and Vessel FPL Response FPL participated in the PWR Owners Group (PWROG) program to evaluate downstream effects related to in-vessel long-term cooling. The results of the PWROG program are documented in WCAP16793-NP (WCAP-16793-NP "Evaluation of Long-Term Cooling Considering Particulate, Fibrous and Chemical Debris in the Recirculating Fluid," Rev. 0, May, 2007) which was provided to the NRC Staff for review on June 4, 2007. The program was performed such that the results apply to the entire fleet of PWRs, regardless of the design (e.g., Westinghouse, CE, or B&W).

The PWROG program demonstrated that the effects of fibrous debris, particulate debris, and chemical precipitation would not prevent adequate long-term core cooling flow from being established. In the cases that were evaluated, the fuel clad temperature remained below 800 OF in the recirculation mode. This is well below the acceptance criterion of 2200 °F in 10 CFR 50.46, "Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors." The specific conclusions reached by the PWROG are noted below.

Adequate flow to remove decay heat will continue to reach the core even with debris from the sump reaching the RCS and core. Test data has demonstrated that any debris that bypasses the screen is not likely to build up an impenetrable blockage at the core inlet.

While any debris that collects at the core inlet will provide some resistance to flow, in the extreme case that a large blockage does occur, numerical analyses have demonstrated that core decay heat removal will continue.

Decay heat will continue to be removed even with debris collection at the fuel assembly spacer grids. Test data has demonstrated that any debris that bypasses the screen is small and consequently is not likely to collect at the grid locations. Further, any blockage that may form will be limited in length and not be impenetrable to flow. In the extreme case that a large blockage does occur, numerical and first principle analyses have demonstrated that core decay heat removal will continue.

Fibrous debris, should it enter the core region, will not tightly adhere to the surface of fuel cladding. Thus, fibrous debris will not form a "blanket" on clad surfaces to restrict heat transfer and cause an increase in clad temperature. Therefore, adherence of fibrous debris to the cladding is not plausible and will not adversely affect core cooling.

WCAP 16793-NP Rev. 0 concluded that the calculations, summarized in the bullets above, for fiber debris are applicable to all PWRs, hence they are applicable to Turkey Point Unit 4.

Using an extension of the chemical effects method developed in WCAP-16530-NP to predict chemical deposition of fuel cladding, two sample calculations using large debris loadings of fiberglass and calcium silicate, respectively, were performed and are reported in WCAP-16793-NP, Rev. 0, Appendix E. The cases demonstrate that decay heat would be removed and acceptable fuel clad temperatures would be maintained. However, FPL has performed a plant-specific calculation using Turkey Point Unit 4 parameters and the recommended WCAP methodology to confirm that chemical plate-out on the fuel does not result in the prediction of fuel cladding temperatures approaching the 800 OF value. This calculation concluded that the maximum fuel cladding temperature is 366.04 OF.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 53 of 78 The Turkey Point Unit 4 responses to the NRC staff's Limits and Conditions related to the staff review of WCAP 16793-NP are provided in Attachment 2, Enclosure 2.

The Turkey Point Unit 4 responses to the NRC staff's Limits and Conditions related to the staff review of WCAP 16530-NP are provided in Attachment 2, Enclosure 3.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 54 of 78 Topic 3.0: Chemical Effects FPL Response The permanent replacement strainers were installed during refueling outage PT4-24 (spring 2008) in accordance with the GL 2004-02/GSI-191 extension requested in the letter L-2006-028 dated January 27, 2006 and approved by the NRC on April 13, 2006.

AREVA NP, Performance Contracting, Inc. (PCI), and Alden Research Laboratory, Inc.

(ALDEN) performed the testing of a PCI Sure-Flow prototype strainer to determine the head loss of the strainer based on the water flow and debris mix conditions expected in the Turkey Point Unit 4 containment following a postulated Loss of Cooling Accident (LOCA). The testing was performed at ALDEN in Holden, Massachusetts, during the weeks of 3/24/08 and 4/3/08.

The testing was witnessed by personnel from FPL, AREVA NP, and PCI.

After accounting for head losses due to debris, chemical, and temperature dependent effects, the new strainer system provides a minimum NPSH margin of 7.22 ft for the period prior to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months and 6.53 ft for the period after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

The NRC Issues related to Topic 3.0 in accordance with Enclosure 3, chemical effects, to the letter from the NRC to NEI dated September 27, 2007 are presented below. The responses to those issues are then presented, as applicable to Turkey Point Unit 4. Additionally, answers to the chemical effects RAIs are presented below.

The objective of the chemical effects section is to evaluate the effect that chemical precipitates have on head loss and core cooling.

1. Provide a summary of evaluation results that show that chemical precipitates formed in the post-LOCA containment environment, either by themselves or combined with debris, do not deposit at the sump screen to the extent that an unacceptable head loss results, or deposit downstream of the sump screen to the extent that long-term core cooling is unacceptably impeded.

2. Content guidance for chemical effects is provided in Enclosure 3 to a letter from the NRC to NEI dated September 27, 2007 (ADAMS Accession No. ML0726007425).

2.1 Sufficient 'Clean' Strainer Area: Those licensees performing a simplified chemical effects analysis should justify the use of this simplified approach by providing the amount of debris determined to reach the strainer, the amount of bare strainer area and how it was determined, and any additional information that is needed to show why a more detailed chemical effects analysis is not needed.

2.2 Debris Bed Formation: Licensees should discuss why the debris from the break location selected for plant-specific head loss testing with chemical precipitate yields the maximum head loss. For example, plant X has break location 1 that would produce maximum head loss without consideration of chemical effects. However, break location 2, with chemical effects considered, produces greater head loss than break location 1. Therefore, the debris for head loss testing with chemical effects was based on break location 2.

2.3 Plant Specific Materials and Buffers: Licensees should provide their assumptions (and basis for the assumptions) used to determine chemical effects loading: pH

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 55 of 78 range, temperature profile, duration of containment spray, and materials expected to contribute to chemical effects.

2.4 Approach to Determine Chemical Source Term (Decision Point): Licensees should identify the vendor who performed plant-specific chemical effects testing.

2.5 Separate Effects Decision (Decision Point): State which method of addressing plant-specific chemical effects is used.

2.6 AECL Model: Since the NRC USNRC is not currently aware of the testing approach, the NRC USNRC expects licensees using it to provide a detailed discussion of the chemical effects evaluation process along with head loss test results. Licensees should provide the chemical identities and amounts of predicted plant-specific precipitates.

2.7 WCAP Base Model: Input of plant parameters into the WCAP-16530 spreadsheet should be done in a manner that results in a conservative amount of precipitate formation. In other words, plant parameter inputs selection will not be biased to lower the predicted amount of precipitate beyond what is justified. Analysis, using timed additions of precipitates based on WCAP-16530 spreadsheet predictions should account for potential non-conservative initial aluminum release rates.

Licensees should list the type (e.g., AIOOH) and amount of predicted plant-specific precipitates.

2.8 WCAP Refinements: State whether refinements to WCAP-16530-NP were utilized in the chemical effects analysis. Conservative assumptions in the WCAP-16530 base model were intended to balance uncertainties in the GSI-191 chemical effects knowledge. Therefore, overall chemical effects assessment remains conservative when implementing these model refinements.

2.9 Solubility of Phosphates, Silicates and Al Alloys: Licensees should clearly identify any refinements (plant-specific inputs) to the base WCAP-1 6530 model and justify why the plant-specific refinement is valid.

2.10 Precipitate Generation (Decision Point): State whether precipitates are formed by chemical injection into a flowing test loop or whether the precipitates are formed in a separate mixing tank.

2.11 Chemical Injection into the Loop: Licensees should provide the one-hour settled volume (e.g., 80 ml of 100 ml solution remained cloudy) for precipitate prepared with the same sequence as with the plant-specific, in-situ chemical injection.

2.12 Pre-Mix in Tank: Licensees should discuss any exceptions taken to the procedure recommended for surrogate precipitate formation in WCAP-1 6530.

2.13 Technical Approach to Debris Transport (Decision Point): State whether near-field settlement is credited or not.

2.14 Integrated Head Loss Test with Near-Field Settlement Credit: Licensees should provide the one-hour or two-hour precipitate settlement values measured within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of head loss testing.

2.15 Head Loss Testing Without Near Field Settlement Credit: Licensees should provide an estimate of the amount of debris and precipitate that remains on the tank/flume floor at the conclusion of the test and justify why the settlement is acceptable.

2.16 Test Termination Criteria: Provide the test termination criteria.

2.17 Data Analysis: Licensees should provide a copy of the pressure drop curve(s) as a function of time for the testing of record. Licensees should explain any extrapolation methods used for data analysis.

2.18 Integral Generation (Alion): Licensees should discuss why the test parameters (e.g.,

temperature, pH) provide for a conservative chemical effects test.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 56 of 78 2.19 Tank Scaling / Bed Formation: Explain how scaling factors for the test facilities are representative or conservative relative to plant-specific values. Explain how bed formation is representative of that expected for the size of materials and debris that is formed in the plant specific evaluation.

2.20 Tank Transport: Explain how the transport of chemicals and debris in the testing facility is representative or conservative with regard to the expected flow and transport in the plant-specific conditions.

2.21 30-Day Integrated Head Loss Test: Licensees should provide the plant-specific test conditions and the basis for why these test conditions and test results provide for a conservative chemical effects evaluation. Licensees should provide a copy of the pressure drop curve(s) as a function of time for the testing of record.

2.22 Data Analysis Bump Up Factor: Licensees should provide the details and the technical basis that show why the bump-up factor from the particular debris bed in the test is appropriate for application to other debris beds.

Issue 3.o.1:

Chemical precipitates that form in the post-LOCA containment environment combined with debris do not result in an unacceptable head loss. The effects of the sump chemical environment were evaluated in an integrated chemical effects head loss test by PCI with support from Areva at the Alden Research Lab. The testing program implemented assumed chemical precipitates do form in accord with the WCAP 16530-NP methodology. The effect of the chemical debris on the head loss across the screen has been measured in a test using the protocol reviewed by the NRC with PCI and the strainer users group. The results of the chemical effects testing have been incorporated into the NPSH calculations as discussed in section 3.g above.

Issue 3.o.2.

Content Guide for Chemical Effects Evaluation. The chemical effects evaluation process flow chart provided in the NRC guidance document has been modified, as shown in Figure 3.o-1, to highlight the process approach taken for testing and evaluation.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 57 of 78 Figure 3.o-1 Chemical Effects Evaluation Process Flow Chart Issue 3.o.2.1 Turkey Point Unit 4 did not perform a "simplified" chemical effects evaluation.

Issue 3.o.2.2 As discussed in section 3.a, a break at the B hot leg generates the greatest quantity of particulate and fibrous debris and therefore, was selected for the strainer design basis. During the integrated test, inspections were performed that confirmed that a fibrous thin bed was not formed upon completion of debris loaded testing. Therefore, the break at the B hot leg, which generated the greatest quantity of particulate and fibrous debris, yields the maximum head loss.

Issue 3.o.2.3 The following assumptions were used to determine the chemical effects loading.

The temperature profile used to calculate the possible chemical effects is based on the FSAR temperature curves for accident analysis. The temperature profiles presented in the FSAR are conservative since the safety analyses assume single failures of portions of ECCS/CS supply to yield higher containment pressures and temperatures. The maximum temperature profile was from 240°F up to 2560 F and then down to 122TF. Note the temperature profile was reduced by 5°F and 10°F for separate case studies to ensure that the higher temperatures produced the maximum amount of chemicals. The bounding chemical effects were determined to be at the higher temperature.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 58 of 78

The duration of containment spray is assumed to be 30 days.

Plant specific values of the quantities of materials that contribute to chemical effects were utilized. Aluminum, concrete, Nukon insulation, cal-sil, and NaTB were utilized as inputs in the analysis.

Issue 3.o.2.4, The effects of the sump chemical environment were evaluated in an integrated chemical effects head loss test by PCI with support from Areva at the Alden Research Lab.

Issue 3.o.2.5 The effects of the sump chemical environment were evaluated in an integrated chemical effects head loss test by PCI with support from Areva at the Alden Research Lab. The testing program implemented assumed chemical precipitates do form in accord with the WCAP 16530-NP methodology.

Issue 3.o.2.6 Turkey Point Unit 4 does not use the AECL based models for testing.

Issue 3.0.2.7 Bounding maximum debris volumes, material surface areas, and temperature and pH transient profiles were used as inputs for this analysis. Plant-specific design information was utilized as inputs.

The total mass of chemical precipitate expected to form post-LOCA was calculated as 1182.27 kg. The types and quantities of chemical precipitates expected to form in the Turkey Point Unit 4 containment sump and reactor coolant system following a Design Basis LOCA are as follows; 492.29 kg of sodium aluminum silicate (NaAISi 3O,) and 689.97 kg of aluminum oxyhydroxide (AIOOH). This analysis was comprised of the bounding set of inputs.

Issue 3.o.2.8 The chemical precipitates were calculated utilizing the methodology in WCAP-16530-NP. No refinements to WCAP-16530-NP were utilized in the chemical effects analysis.

Issue 3.o.2.9 The chemical precipitates were calculated utilizing the methodology in WCAP-16530-NP. No refinements to WCAP-16530-NP were utilized in the chemical effects analysis.

Issue 3.o.2.10 Precipitates used in testing are formed in a separate mixing tank and subsequently introduced into the test loop.

Issue 3.o.2.11 Chemical injection into the test loop was not used for Turkey Point Unit 4 testing.

Issue 3.o.2.12 The chemical precipitates were generated utilizing the methodology in WCAP-16530-NP and final SER, and PWROG letter OG-07-270. The chemical materials were generated in mixing tanks and introduced into the test flume within the parameters provided in the PWROG letter OG-07-270. Aluminum Oxyhydroxide (AIOOH) was injected based on the predicted chemical formation.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 59 of 78 Section 7.3.2 of WCAP-16530-NP, Rev. 0, states that the characteristics of sodium aluminum silicate are sufficiently similar to aluminum oxyhydroxide (AIOOH), thus AIOOH was used in lieu of sodium aluminum silicate. Based on Section 7.3.2 of WCAP-16530-NP Rev. 0, the production of sodium aluminum silicate is considered hazardous. Therefore, AIOOH was generated in accordance with the directions in Section 7.3.2 of WCAP-1 6530-NP for strainer testing when either AIOOH or sodium aluminum silicate is required.

Issue 3.o.2.13 Near field settlement was credited by the design of the test. The test flume walls were arranged such that the velocity fields around the testing strainer were representative or bounding of the expected velocity fields in the containment building during a LOCA (see section 3.e, Debris Transport). The objective of this test protocol was to allow debris settling as it can occur in the actual post-LOCA environment.

Issue 3.o.2.14 Testing was performed within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of precipitate mixing with preparation in accordance with WCAP-16530. Settling rates were verified to be acceptable in accordance with the WCAP criteria.

Issue 3.o.2.15 Turkey Point Unit 4 utilized near field settling. Therefore, this section is not applicable Issue 3.o.2.16 The termination criterion for this test is if the change in head loss is less than 1% in the last 30 minute time interval and a minimum of 15 flume turnovers after all the debris has been inserted into the test flume.

Issue 3.o.2.17 Based on the test results, the Design Basis Tests head loss was extrapolated over 30 days and resulted in a final head loss of 1.06 feet of water across the face of the screen. This is the pressure drop for debris and chemical effects only. Pressure drop was recorded in data tables and documented in the test report.

The data were analyzed and an exponential curve fit was utilized to extrapolate the head loss to 30 days.

Issues 3.o.2.18 throuqh 3.o.2.22 Turkey Point Unit 4 did not use the Integral Generation of Chemical Products In-Situ (Alion) model for testing. Therefore, sections 3.o.2.18 through 3.o.2.22 are not applicable.

[RAI 2]

The Integrated Chemical Effects Test Project Test #5 Data Report is most applicable to the current plant specific conditions at Turkey Point Unit 4. The comparison between the Turkey Point Unit 4 specific conditions with the parameters in the NRC/industry Integrated Chemical Effects Test plan was performed and is summarized as follows:

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 60 of 78 Material Value of Turkey Point Unit 4 Unit 4 Ratio1 ICET values for submerged and Ratio for the Total Amount unsubmerged Test 2

Zinc in Galvanized Steel 8.0 (ft 2/ft3) 70,000 ft 2.2 (ft 2/ft3) 5% submerged 10% submerged 95% unsubmerged 90% unsubmerged Inorganic Zinc Primer Coating 4.6 (ft 2/ft3) 5000 ft 2 0.16 (ft2/ft3)

(non top coated) 10% submerged 4% submerged 90% unsubmerged 96% unsubmerged 2

Aluminum 3 3.5 (ft 2/ft ) 51,740 ft 1.6 (ft2/ft3) 5% submerged 7.5% submerged 95% unsubmerged 92.5% unsubmerged Copper 3 6.0 (ft 2/ft ) 3452 ft2 0.11 (ft 2/ft3)

(including Cu-Ni alloys) 25% submerged 75% unsubmerged 2

Carbon Steel 0.15 (ft 2/ft3) 100 ft 0.00 (ft 2/ft3) 34% submerged 10% submerged 66% unsubmerged 90% unsubmerged 2

Concrete (uncoated) 0.045 (ft2/ft3) 1300 ft 0.04 (ft 2/ft3) 34% submerged 60% submerged 66% unsubmerged 40% unsubmerged 3

Concrete (particulate) 0.0014 131.3 Ibm 0.004 Ibm/ft 100% submerged (Ibm/ft3) 0% unsubmerged Note 1: Minimum volume of water at the start of recirculation is 32,136 ft3 .

As indicated by the table, the quantities of materials used in the Integrated Chemical Effects Test Project Test #5 Data Report bound the actual conditions at Turkey Point Unit 4.

[RAI 3] For Turkey Point Unit 4, the small amount of carbon steel knuckles and aluminum ladders stored in the containment are included in the debris quantities used for design inputs used to perform the chemical effects testing. The carbon steel DBA-qualified coated scaffold poles and steel ladders are not considered as a contributor for chemical testing.

Turkey Point Unit 4 currently has approval for scaffolding poles and connector storage in containment during power operation for 3,432 square-feet scaffold poles and 507 square-feet galvanized steel connectors. Only scaffolding poles that have a DBA-qualified coating applied are allowed. The connecting knuckles are galvanized steel and are permanently installed or stored in the approved seismically restrained stainless steel barrels. The barrels are sealed and

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 61 of 78 are not a concern for exposure to containment spray or immersion in floodwater.

The scaffold poles on 14'-0" elevation are permanently installed and the pole ends would be submerged in the event of a LOCA. The calculated flood water level is 17.35' post LBLOCA.

For the permanently installed connectors, less than 5 square feet of galvanized steel knuckles would be submerged in LOCA floodwater. There would be no adverse effect due to coatings to the Containment Spray (CS) and Emergency Core Cooling System (ECCS) since only an insignificant amount of galvanized knuckles are submerged.

Six stainless steel ladders are permanently installed in the containment building. The stainless steel ladders are installed on the 58'-0" elevation for Steam Generator A, B & C inspection ports, and there is no adverse impact to the CS and ECCS.

[RAI 4] The metallic coating used at Turkey Point is zinc primer. The response to RAI 2 included an allowance for zinc primer that did not receive an epoxy topcoat.

The response to RAI 2 included an allowance of the insulation jacketing that is aluminum.

[RAI 5] The minimum pH immediately following a LOCA is 4.95. The final pH is achieved by manual addition rather than an automatic addition by fixed chemicals. The EOPs direct addition of the buffer until a pH of 7.2 is obtained. Thus, the beginning or end of a fuel cycle is not relevant.

[RAI 6] The chemical effects evaluation for Turkey Point Unit 4 was completed using the methodology published in WCAP-16530. The chemical effects evaluation did not take credit for any independent chemical effects based benchmark testing results. Therefore, this question is not applicable to the Turkey Point Unit 4 chemical effects evaluation or related strainer performance testing activities. However, the response to RAI 2 shows the quantities of materials used in the Integrated Chemical Effects Test Project Test #5 Data Report bound the actual conditions at Turkey Point Unit 4.

[RAI 7] For Turkey Point Unit 4 the minimum time to initiation of sump recirculation is 30 minutes with an estimated pool temperature of 253 0 F. At 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after LBLOCA, the estimated pool temperature is 174TF. The pool volumes are provided in section 3.g above.

[RAI 8] This RAI requested information on the FPL chemical effects testing program. This information is provided in NRC Topic 3.g, Net Positive Suction Head (NPSH), and NRC Topic 3.o, Chemical Effects.

[RAI 9] There are no plans to remove additional material from containment, and no plans to make a change from the existing chemicals that buffer containment pool pH following a LOCA.

[RAI 10] Bench top testing was not utilized for Turkey Point Unit 4.

[RAI 11] Performance Contracting, Inc., along with team members AREVA NP, Inc. and Alden Research Laboratories are the vendors who defined the test plan for the specified design basis.

The test plan protocol implemented was developed with the NRC staff beginning in April 2007, and the NRC staff has reviewed the protocol in detail prior to its actual implementation. This protocol was further refined following comments from NRC staff members who witnessed tests in January and February 2008.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 62 of 78 Testing used Holden, MA city tap water pre-heated and maintained to a nominal 120 IF temperature. Prior to testing, CFD analyses were implemented to define a "bounding" flow stream in one foot increments to the screen. The objective of this test protocol was to allow debris settling that can occur in the actual post-LOCA environment.

Non-chemical debris was procured and produced in accord with PCI standards; also in accordance with discussions held with the NRC staff over the same review period. Non-chemical debris was introduced in accord with NRC preferences; namely, particulates first; then fine fibers; then smalls, etc.

Chemical debris was produced and accepted for use in accordance with the WCAP 16530-NP in a chemical tank prior to its introduction into the flume. Introduction of acceptable precipitates always occurred within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of its manufacture.

Since PCI implemented the WCAP 16530-NP to define the quantities and types of chemical precipitates to be formed in the post-LOCA, and generated/qualified these precipitates in accord with the WCAP 16530-NP and NRC preferences, the effect of the post-LOCA environment is bounded in the implemented test protocol.

[RAI 12] This RAI requested FPL provide the maximum projected head loss resulting from chemical effects (a) within the first day following a LOCA, and (b) during the entire ECCS recirculation mission time. The overall chemical effects testing program is discussed in NRC Topic 3.o, Chemical Effects, and the resulting NPSH is discussed in NRC Topic 3.g, Net Positive Suction Head (NPSH). Note that the full 30 day debris load (both chemical and non chemical) is applied at the initiation of recirculation. This is extremely conservative since as the chemical products are being created during the 30 days, the sump pool is cooling down providing additional NPSH margin.

[RAI 13] The WCAP 16530-NP methodology was utilized to define the quantities and types of chemical precipitates to be formed post-LOCA. The results of the Integrated Chemical Effects Test Project Test #5 were not directly utilized for chemical effects testing. Therefore, the effect of the post-LOCA environment is bounded in the implemented test protocol.

[RAI 15] At the time of the September 1 response, it was planned to change the buffering agent from sodium tetraborate (borax) to tri-sodium phosphate (TSP). Subsequently, in consideration of results from the industry Integrated Chemical Effects Tests (ICET), FPL notified the NRC in L-2006-028, dated January 27, 2006, that this buffer change will not be implemented.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 63 of 78 Topic 3.p: Licensing Basis FPL Response No changes to the plant licensing basis were required to ensure compliance with the regulatory requirements of GL 04-02. However, the Technical Specification Bases and the ECCS procedures have been updated to incorporate the new strainer design basis. These changes did not affect the plant licensing basis or existing UFSAR analyses. All of the changes were completed in accordance with the requirements of 10 CFR 50.59.

The Technical Specification Bases were updated to expand the definition of the recirculation sump inspection requirements to include the entire distributed sump strainer system. This change ensures that the entire system will come under the technical specification requirements for sump inspection and control.

Previously, two of the seven allowable ECCS/CSS recirculation pump alignments operated both RHR/LHSI pumps simultaneously. These pumps are redundant, and the other five alignments operate only one of the redundant pumps. The design basis sump strainer flow is consistent with the plant design basis which relies on a single RHR/LHSI pump. Therefore, because the ECCS/CSS alignments that operated two RHR/LHSI pumps simultaneously are were not needed to meet design basis requirements and exceed the design flow of the new sump strainers, they have been removed from the emergency operating procedures.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 64 of 78 Enclosure 1 (Turkey Point Unit 4 Updated Supplemental Response)

NRC Safety Evaluation Report Limitations and Conditions for WCAP 16406-NP Revision 0

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 65 of 78 L&C No. NRC Limitations & Conditions (WCAP-16406-NP Rev. 0) FPL (Turkey Point Unit 4) Response

1. Where a TR WCAP-1 6406-P, Revision 1, section or General WCAP-16406-P examples and technical appendix refers to examples, tests, or general technical data were not used for site specific input. The data, a licensee should compare and verify that the wear equations developed in the WCAP-16406-P information is applicable to its analysis. based on tests and general technical data were developed and benchmarked on equipment and with debris similar to that found at Turkey Point Unit 4. The wear equations were adjusted for the specific materials and debris concentration at Turkey Point Unit 4.

2. A discussion of EOPs, AOPs, NOPs or other plant-reviewed The downstream effects analysis for Turkey Point alternate system line-ups should be included in the overall Unit 4 considered all procedural recirculation system and component evaluations as noted in the NRC system line-ups that are used by the plant, staffs SE of NEI 04-07, Section 7.3 (Reference 13). including any alternate line-ups. Analysis of components in the alternate flowpaths was performed for the full recirculation mission time, like the primary flowpath components. The system evaluation discusses the procedures and alternate system line-ups.

3. A licensee using TR WCAP-16406-P, Revision 1, will need The downstream effects analysis uses a bounding to determine its own specific sump debris mixture and sump site-specific sump debris mixture and the actual screen size in order to initiate the evaluation. sump strainer hole size. Since site specific debris bypass test data were not available, the WCAP-16406-P methodology of strainer efficiency and retention size were utilized. The assumed maximum particulate size capable of passing the strainer was altered from the suggested WCAP-16406-P approach. Fiber penetration size was not available and therefore not considered within the calculation; fibrous debris was modeled as completely depletable based on strainer capture efficiency, only. Debris size distribution was determined based on experimental data (not site specific) and the Turkey Point Unit 4 specific debris types were used.

4. TR WCAP-16406-P, Revision 1, Section 4.2, provides a Recirculation operation is analyzed for 30 days general discussion of system and component mission times. post-LOCA. The mission time of all components It does not define specific times, but indicates that the is 30 days unless the plant's recirculation defined term of operation is plant-specific. As stated in the procedures limit the time that specific components NRC staffs SE of NEI 04-07, Section 7.3 (Reference 13), are used. The 30 day recirculation duration is each licensee should define and provide adequate basis for based on the SE of NEI 04-07, and was reviewed the mission time(s) used in its downstream evaluation. and found to be consistent (does not conflict) with the Turkey Point Unit 4 design and licensing basis.

5. TR WCAP-16406-P, Revision 1, Section 5.8, assumes that Turkey Point Unit 4 utilizes lower plenum injection.

the coolant which is not spilled flows into the reactor system and reaches the reactor vessel downcomer. This would be true for most PWR designs except for plants with UPI.

Therefore, the methodology of Section 5.8 may not be applicable to plants with UPI and its use should be justified on a plant-specific basis.

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6. TR WCAP-16406-P, Revision 1, Section 5.8, provides The initial particulate debris concentration was equations which a licensee might use to determine determined for Turkey Point Unit 4 based on a particulate concentration in the coolant as a function of time. plant-specific limiting debris loads and sump water Assumptions as to the initial particulate debris concentration volumes. Debris depletion in the calculations is are plant-specific and should be determined by the licensee. based on plant specific flows, debris types and In addition, model assumptions for ECCS flow rate, the debris concentrations. The size of debris subject fraction of coolant spilled from the break and the partition of to settling in the lower plenum was determined on large heavy particles which will settle in the lower plenum a plant-specific basis; the ECCS flows and and smaller lighter particles which will not settle should be spillage assumed are the most conservative for determined and justified by the licensee. this purpose.

7. TR WCAP-16406-P, Revision 1, Sections 5.8 and 5.9, The site specific debris settling size is determined assumes that debris settling is governed by force balance in downstream calculations which were according methods of TR Section 9.2.2 or Stokes Law. The effect of to force balance methods. The methodology uses debris and dissolved materials on long-term cooling is being empirical friction factors based on the debris evaluated under TR WCAP-16793-NP (Reference 12). If shape. This methodology is benchmarked against the results of TR WCAP-16793-NP show that debris settling the NRC-sponsored testing of paint chip settling is not governed by force balance methods of TR Section reported in NUREG/CR-6916.

9.2.2 or Stokes Law, then the core settling term determined from TR WCAP-16793-NP should be used.

8. TR WCAP-16406-P, Revision 1, Section 7.2, assumes a Analysis was performed for a mission time of thirty mission time of 720 hours0.00833 days 0.2 hours 0.00119 weeks 2.7396e-4 months for pump operation. Licensees days following initiation of LBLOCA event. No should confirm that 720 hours0.00833 days 0.2 hours 0.00119 weeks 2.7396e-4 months bounds their mission time or reduction in mission time is credited in this provide a basis for the use of a shorter period of required analysis. The use of a full thirty day mission time operation. is consistent with NEI 04-07 and its NRC SER, and the UFSAR. Additionally, use of a 30 day mission time is consistent with the time periods anticipated in NUREG 0800, Section 9.2.5, Ultimate Heat Sink. Reasonable and prudent management and operator action is credited for any actions required beyond thirty days to ensure continued safe operation of needed ECCS and CSS pumps. The mission time of individual components was a full 30 days except where the plant's recirculation procedures limit the time that specific components are used.

9. TR WCAP-16406-P, Revision 1, Section 7.2, addresses The downstream effects calculation considers the wear rate evaluation methods for pumps. Two types of wear maximum of either free-flow or packing type are discussed: 1) free-flowing abrasive wear and 2) packing- abrasive wear until a wear ring clearance of 50 type abrasive wear. Wear within close-tolerance, high-speed mils diametral is reached. Beyond that time, the components is a complex analysis. The actual abrasive packing is assumed expelled and free-flow wear wear phenomena will likely not be either a classic free- (abrasive and erosive) is modeled.

flowing or packing wear case, but a combination of the two.

Licensees should consider both in their evaluation of their components.

10. TR WCAP-16406-P, Revision 1, Section 7.2.1.1, addresses Debris depletion coefficients in the calculations debris depletion coefficients. Depletion coefficients are are based on plant specific flows, debris types and plant-specific values determined from plant-specific debris concentrations and the strainer design.

calculations, analysis, or bypass testing. Licensees should The ECCS flows and spillage assumed are the consider both hot-leg and cold-leg break scenarios to most conservative for this purpose of either cold or determine the worst case conditions for use in their plant hot-leg break scenarios. The calculated plant-specific determination of debris depletion coefficient. specific depletion coefficient is only utilized where it is lower than (i.e., more conservative) the WCAP-16406-P lower-limit values.

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11. TR WCAP-16406-P, Revision 1, Section 7.3.2.3, recognizes Wear of elastomeric materials, reduced by a factor that material hardness has an effect on erosive wear. TR of 10, is not applicable to any of the downstream WCAP-16406-P, Revision 1, suggests that "For elastomers, effects wear calculations.

the wear rate is at least one order of magnitude less than steel. Therefore, for soft-seated valves, divide the estimated wear rate of steel from above equations by 10 per Appendix F." The NRC staff agrees that the wear rates of elastomers are significantly less than for steels. However, the wear coefficient should be determined by use of a suitable reference, not by dividing the steel rate by a factor of 10.

12. TR WCAP-16406-P, Revision 1, Section 8.1.1.2, "Evaluation Non-mechanistic failure of an ECCS or CSS pump of ECCS Pumps for Operation with Debris-Laden Water seal is considered as a single-failure in the plant from the Containment Sump," states that "Sufficient time is design basis and is acceptable. The WCAP-available to isolate the leakage from the failed pump seal 16406-P attempts to justify failure of the seals due and start operation of an alternate ECCS or CSS train." to recirculation debris, which is a potential Also, Section 8.1.3, "Mechanical Shaft Seal Assembly," common-mode failure. The pump seals at Turkey states: "Should the cooling water to the seal cooler be lost, Point Unit 4 have been evaluated as not the additional risk for seal failure is small for the required susceptible to failure by debris-laden water mission time for these pumps." These statements refer only because they recirculate seal cavity fluid.

to assessing seal leakage in the context of pump operability Therefore the only potential failure that must be and 10 CFR Part 100 concerns. A licensee should evaluate considered is an assumed single failure, which leakage in the context of room habitability and room again is part of the existing design basis of the equipment operation and environmental qualification, if the plant (bounded by a moderate energy line break in calculated leakage is outside that which has been previously the pump room). The potential effect of debris assumed. causing an increased leakage flow through the disaster bushing following that single-failure has been evaluated and determined to be acceptable.

13. TR WCAP-16406-P, Revision 1, Section 8.1.3, discusses The CS pump seal configuration at Turkey Point cyclone separator operation. TR WCAP-16406-P, Revision Unit 4 was modified to utilize recirculated seal 1, generically concludes that cyclone separators are not cavity fluid in the seal, which included removal of desirable during post-LOCA operation of HHSI pumps. The the cyclone separators. The resulting seal NRC staff does not agree with this generic statement. If a configuration is consistent with that already licensee pump contains a cyclone separator, it should be utilized on the LHSI and HHSI pumps.

evaluated within the context of both normal and accident operation. The evaluation of cyclone separators is plant-specific and depends on cyclone separator design and the piping arrangement for a pump's seal injection system.

14. TR WCAP-16406-P, Revision 1, Section 8.1.4, refers to The pump wear analysis assumes 30 days of pump vibration evaluations. The effect of stop/start pump continuous wear. Turkey Point Unit 4 procedure operation is addressed only in the context of clean water does not direct to stop then start the ECCS/CSS operation, as noted in Section 8.1.4.5 of TR WCAP-16406- pumps during recirculation. In the event the P, Revision 1. If an ECCS or CSS pump is operated for a pumps must be stopped and restarted, the period of time and builds up a debris "packing" in the tight Archard wear model assumed the highest friction clearances, stops and starts again, the wear rates of those factors and eccentricity postulated by the WCAP-areas may be different due to additional packing or 16406-P. Therefore, any "additional packing" that imbedding of material on those wear surfaces. Licensees could be caused by stopping and starting the who use stop/start operation as part of their overall ECCS or pumps is bounded by the Archard model used.

CSS operational plan should address this situation in their evaluation.

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15. TR WCAP-16406-P, Revision 1, Section 8.1.4, states: The plant's procedures were not changed to "should the multistage ECCS pumps be operated at flow reflect the WCAP-16406-P concerns. The Turkey rates below 40% of BEP during the containment Point Unit 4 multistage pumps performed recirculation, one or more of the pumps should be secured adequately with respect to pump design and plant to bring the flow rate of the remaining pump(s) above this design basis before GSI-191 concerns. The pump flow rate." The NRC staff does not agree with this assessment concludes that the HHSI pumps statement. System line-ups and pump operation and continue to be capable of performing their operating point assessment are the responsibility of the intended design basis functions based on the licensee. Licensees must ensure that their ECCS pumps pump's hydraulic characteristics after 30 days of are capable of performing their intended function and the wearing.

NRC has no requirements as to their operating point during the recirculation phase of a LOCA.

16. TR WCAP-16406-P, Revision 1, Section 8.1.5, makes a The pump wear analysis assumed a starting wear generic statement that all SI pumps have wear rings that are ring clearance as the average of the vendor good "as new" based solely upon "very little service beyond recommended gap range. The combination of low inservice testing." A stronger basis is needed to validate run time and very clean fluids would justify an this assumption, if used (e.g., maintenance, test and assumption that the wear rings are "as good as operational history and/or other supporting data). new" and thus closer to the low end of the recommended ring clearance, but the wear calculation conservatively assumes that the wear rings are mid-way between the lower and the upper ring clearance recommended by the pump manufacturers.

17. TR WCAP-16406-P, Revision 1, Section 8.3, identifies The minimum heat exchanger tube velocity was criteria for consideration of tube plugging. Licensees should calculated and compared to the bounding particle confirm that the fluid velocity going through the heat settling velocity. No heat exchangers were found exchanger is greater than the particle settling velocity and to be susceptible to debris settling within the evaluate heat exchanger plugging if the fluid velocity is less tubes.

than the settling velocity.

18. TR WCAP-16406-P, Revision 1, Section 8.6, refers to The evaluation of instrumentation tubing was evaluation of instrumentation tubing and system piping. based primarily on the instrument line's specific Plugging evaluations of instrument lines may be based on configuration, and then upon the local flow velocity system flow and material settling velocities, but they must for instrument lines oriented below the horizontal consider local velocities and low-flow areas due to specific datum. Plant-specific layout and actual local flow plant configuration. velocities were used in all cases.

19. TR WCAP-16406-P, Revision 1, Sections 8.6.7, 8.6.8, 8.6.9, The Turkey Point Unit 4 RVLIS design was and 8.6.10 describe, in general terms, the Westinghouse, compared to the generic designs reviewed and CE, and B&W RVLIS. TR WCAP-16406-P, Revision 1, deemed acceptable by the WCAP-16406-P.

recommends that licensees evaluate their specific Turkey Point Unit 4 utilizes a Heated Junction configuration to confirm that a debris loading due to Thermocouple System consisting of eight pairs of settlement in the reactor vessel does not effect the operation heated/unheated thermocouples. Two pairs of of its RVLIS. The evaluation of specific RVLIS design and thermocouples are located in the upper head operation is outside the scope of this SE and should be region above the upper support plate and six pairs performed in the context of a licensees reactor fuel and are located in the upper plenum region between vessel evaluations. the core alignment and support plates. Since the probes are not in the lower plenum where debris could potentially settle, debris settling will not affect the operation of the RVLIS.

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20. TR WCAP-16406-P, Revision 1, Section 8.7, refers to ECCS and CSS system piping was checked for evaluation of system piping. Plugging evaluations of system potential plugging due to debris settling. At each piping should be based on system flow and material settling control valve in the recirculation systems, the velocities. Licensees should consider the effects of local minimum expected system flow rates in each line velocities and low-flow areas due to specific plant were used to minimize the flow velocity and configuration. A piping wear evaluation using the free- compared to the bounding settling velocity. The flowing wear model outlined in Section 7 should be evaluation at control valve locations considered performed for piping systems. The evaluation should the local flow velocities of all the various line sizes consider localized high-velocity and high-turbulence areas. and flow rates used for recirculation in the Turkey A piping vibration assessment should be performed if areas Point Unit 4 ECCS and CSS. All lines were found of plugging or high localized wear are identified. acceptable with respect to plugging. Regarding wear, the material wear of the bounding ECCS/CSS orifice, which sees much higher wear than system piping, was compared to the pipe wall thicknesses in the recirculation lines. The material wear was found to be insignificant compared to the pipe wall thickness. Therefore, all pipes were determined to have sufficient wear margin, and the erosion was considered so slight as to not require vibration analysis.

21. TR WCAP-16406-P, Revision 1, Section 9, addresses A plant specific analysis using the Westinghouse reactor internal and fuel blockage evaluations. This SE LOCA deposition Model in reference to WCAP summarizes seven issues regarding the evaluation of 16793 was performed for Turkey Point Unit 4.

reactor internal and fuel. The PWROG indicated that the The results of the calculation yielded a maximum methodology presented in TR WCAP-16793-NP (Reference fuel cladding temperature and thickest calculated

15) will address the seven issues. Licensees should refer to scale well below the threshold criteria, see NRC TR WCAP-16793-NP and the NRC staffs SE of the TR Topic 3.n, Downstream Effects - Fuel and Vessel.

WCAP-16793-NP, in performing their reactor internal and fuel blockage evaluations. The NRC staff has reached no conclusions regarding the information presented in TR WCAP-16406-P, Section 9.

22. TR WCAP-16406-P, Revision 1, Table 4.2-1, defines a plant This WCAP-16406-P guidance was not utilized.

Category based on its Low-Head / Pressure Safety Injection Turkey Point Unit 4 has single-failure tolerant hot-to RCS Hot-Leg Capability. Figure 10.4-2 implies that leg recirculation capability as part of the existing Category 2 and 4 plants can justify LHSI for hot-leg design and licensing basis. No credit was taken recirculation. However, these categories of plants only have for a single hot-leg injection pathway as one hot-leg injection pathway. Category 2 and Category 4 suggested by the WCAP-16406-P.

plant licensees should confirm that taking credit for the single hot-leg injection pathway for their plant is consistent with their current hot-leg recirculation licensing basis.

23. TR WCAP-16406-P, Revision 1, Appendix F, discusses The debris and wear models were conservatively component wear models. Prior to using the free-flowing applied to ensure that they conservatively predict abrasive model for pump wear, the licensee should show expected wear. Actual pump dimensions, that the benchmarked data is similar to or bounds its plant characteristics, and materials, and the actual plant conditions. debris concentration were utilized in predicting pump wear.

24. TR WCAP-16406-P, Revision 1, Appendix H, references The pump calculations all assume that the starting American Petroleum Institute (API) Standard 610, Annex 1 point for the wear rings is the midpoint of the eighth edition. This standard is for newly manufactured manufacturers recommended ring clearance (see pumps. Licensees should verify that their pumps are "as #16, above). Since the pumps rings are in new good as new" prior to using the analysis methods of API- condition, the analysis methods of API-610 are 610. This validation may be in the form of maintenance applicable.

records, maintenance history, or testing that documents that the as-found condition of their pumps.

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25. TR WCAP-16406-P, Revision 1, Appendix I, provides This SER limitation is simply a statement of the guidelines for the treatment, categorization and amount of limit of the NRC's review; no action is required.

DBA Qualified, DBA Acceptable, Indeterminate, DBA For reference, however, the amount of specific Unqualified, and DBA Unacceptable coatings to be used in a types of coatings used in the downstream effects licensee's downstream sump debris evaluation. A technical analysis was determined on a plant-specific basis review of coatings generated during a DBA is not within the considering the types of coatings actually in use in scope of this SE. For guidance regarding this subject see the Turkey Point Unit 4 containment.

the NRC staffs SE of NEI-04-07 (Reference 13) Section 3.4 "Debris Generation."

26. TR WCAP-16406-P, Revision 1, Appendix J, derives an This approach that is "only applicable to screens" approach to determining a generic characteristic size of was only applied to the sump screens (strainers in deformable material that will pass through a strainer hole. the case of Turkey Point Unit 4). The This approach is only applicable to screens and is not characteristic size of debris that can pass through applicable to determining material that will pass through the sump strainer was calculated and then other close tolerance equipment. compared to the smallest passages of downstream components. The component was deemed acceptable where the smallest passage is larger than this characteristic size, in other words the deformation of the debris was not credited to allow it to pass the downstream close tolerances.

27. TR WCAP-16406-P, Revision 1, Appendix 0, Section 2.2, The Archard model wear coefficient utilized in the states that the wear coefficient, K, in the Archard Model is Turkey Point Unit 4 HHSI pump wear analysis is determined from testing. The wear coefficient (K) is more the "conservative upper bound" suggested by the uncertain than the load centering approach and K may vary WCAP-16406-P and 5 times larger than the value widely. Therefore, licensees should provide a clear basis, in actually used in the WCAP-16406-P example. Its their evaluation, for their selection of a wear coefficient. use resulted in calculated wear greater than the amount seen in the Davis-Besse testing. The materials, debris types and concentrations are comparable. Therefore, the K-value used appears to be the best conservative information available on ECCS pump wear when exposed to insulation and coating debris.

28. TR WCAP-16406-P, Revision 1, Appendix P, provides a The methodology of Appendix P was not used in method to estimate a packing load for use in Archard's wear the determination of packing loads. The Turkey model. The method presented was benchmarked for a Point Unit 4 calculation utilized the methodology single situation. Licensees are expected to provide a discussed in Appendix 0 of WCAP-16406-P discussion as to the similarity and applicability to their (centering load) for defining loads to be used in conditions. The licensee should incorporate its own specific the packing wear model, and specific design design parameters when using this method. parameters were applied to that methodology.

29. TR WCAP-16406-P, Revision 1, Appendix Q, discusses 9.02E-5 (mils/hr)/10 PPM was not used as the free bounding debris concentrations. Debris concentrations are flowing abrasive wear constant at the plant. The plant-specific. If 9.02E-5 (mils/hr)/10 PPM is to be used as wear rate was calculated for each pump's actual the free flowing abrasive wear constant, the licensee should material hardness and actual debris show how it is bounding or representative of its plant. concentrations, including application of the bounding debris penalty as required.

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30. TR WCAP-16406-P, Revision 1, Appendix R, evaluates a Acceptance criteria and stiffness values from Pacific 11-Stage 2.5" RLIJ pump. The analysis was Appendix R were not used. All pump calculations performed by the PWROG using specific inputs. ECCS utilize plant specific information and data to pumps with running clearance designs and dimensions perform wear calculation and shaft stiffness significantly different than those covered by the analysis evaluations. Example data from the WCAP-should be subjected to pump-specific analysis to determine 16406-P is not used in any calculation. The the support stiffness based on asymmetric wear. If designs and dimensions of the Turkey Point Unit 4 licensees use the aforementioned example, a similarity HHSI pumps were reviewed and found to not be evaluation should be performed showing how the example is significantly different than those covered by the similar to or bounds their situations. WCAP-16406-P analysis.

Multi-stage pumps were evaluated by finding the shaft stiffness at a symmetric increase in wear ring clearance equal to 2.5X as the as-new clearance.

A 2.5X wear ring clearance increase was found acceptable for the Turkey Point Unit 4 HHSI pumps by plant-specific rotor dynamic analysis.

The stiffness of the pumps after debris induced wear was then calculated. The stiffness of the pumps after recirculation asymmetric wear was compared to the allowed stiffness equivalent to a uniform 2.5X initial clearance to judge the acceptability of the pump.

31. Licensees should compare the design and operating The criteria and analysis specific for Pacific 2.5" characteristics of the Pacific 2.5" RLIJ 11 to their specific RLIJ 11 as shown in Appendix S were not used.

pumps prior to using the results of Appendix S in their As stated in response 30 above, all pump component analyses. calculations utilize plant specific information and data to perform wear calculation and shaft stiffness evaluations. Example data from the WCAP-16406-P is not used in any calculation.

Multi-stage pumps were evaluated by finding the shaft stiffness at a symmetric increase in wear ring clearance equal to 2.5X as the as-new clearance.

The stiffness of the pumps after debris induced wear was then calculated. The stiffness of the pumps after recirculation asymmetric wear was compared to the allowed stiffness equivalent to a uniform 2.5X initial clearance to judge the acceptability of the pump

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 72 of 78 Enclosure 2 (Turkey Point Unit 4 Updated Supplemental Response)

NRC Safety Evaluation Report Draft Limitations and Conditions for WCAP 16793-NP Revision 0

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 73 of 78 L&C No. NRC Limitations & Conditions (WCAP-16793-NP Rev. 0) FPL (Turkey Point Unit 4) Response 1 WCAP-16793-NP states that licensees shall either For Turkey Point Unit 4, the bypass testing demonstrate that previously performed bypass testing is represented in WCAP-1 6793-NP, Section 2.1, applicable to their plant-specific conditions, or perform their Blockage at the Core Inlet, is applicable. The own plant-specific testing. The NRC staff agrees with this WCAP LOCA Deposition Model used a bump up factor to represent the bypass debris and allowed stated position. this bypassed material to be deposited in the core in the same manner as a chemical reaction product, see Reference OG-07-534, Transmittal of Additional Guidance for Modeling Post-LOCA Core Deposition with LOCADM Document for WCAP-16793-NP (PA-SEE-0312). In accordance with the referenced methodology, all the Turkey Point Unit 4 plant-specific debris inputs were doubled in the corresponding LOCADM calculation which provided a bump up factor that conservatively bounds any credible bypass fraction for the strainer,

2. There are very large margins between the amount of core A plant specific analysis using the blockage that could occur based on the fuel designs and the Westinghouse LOCA Deposition Model debris source term discussed in the TR and the blockage (LOCADM) was performed for Turkey Point that would be required to degrade the coolant flow to the Unit 4. The results of the calculation yielded point that the decay heat could not be adequately removed, a maximum fuel cladding temperature and Plant-specific evaluations referencing TR WCAP-16793-NP thickest calculated scale well below the should verify the applicability of the TR blockage threshold criteria.

conclusions to the licensees' plant and fuel designs.

(Section 3.2 of this SE)

3. Should a licensee choose to take credit for alternate flow No alternative flow paths were used for

,paths such as core baffle plate holes, it shall demonstrate Turkey Point Unit 4. The flow paths are as that the flow paths would be effective and that the flow holes described in WCAP 16793. No alternative will not be become blocked with debris during a loss-of- flow paths were utilized in the LOCADM.

coolant accident (LOCA) and that the credited flowpath would be effective.

4. Existing plant analyses showing adequate dilution of boric The PWR Owners Group has a project to acid during the long-term cooling period have not develop the approach for boric acid considered core inlet blockage. Licensees shall show that precipitation analyses and evaluations, possible core blockage from debris will not invalidate the Project Number ACS-0264R1, Post LOCA existing post-LOCA boric acid dilution analysis for the plant. Boric Acid Precipitation Analysis Methodology Program. The PWROG provided a response to the NRC for justification of continued operations. FPL will continue to follow the project developments.

5. The staff expects the Pressurized Water Reactor Owners This L&C refers to information to be included Group (PWROG) to revise WCAP-16793-NP to address the in a revision to WCAP 16793-NP.

staffs requests for additional information and the applicant's responses. A discussion of the potential for fuel rod swelling and burst to lead to core flow blockage shall be included in this revision.

6. WCAP-16793 shall be revised to indicate that the licensing Not Applicable. Turkey Point Unit 4 is not an basis for Westinghouse two-loop PWRs is for the upper plenum injection plant. The upper recirculation flow to be provided through the upper plenum plenum injection plants are Westinghouse injection (UPI) ports with the cold-leg flow secured. two-loop PWRs. Turkey Point Unit 4 is a Westinghouse three loop plant.

7. Individual UPI plants will need to analyze boric acid Not Applicable. Turkey Point Unit 4 is not an dilution/concentration in the presence of injected debris for a upper plenum injection plant.

cold-leg break LOCA.

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8. WCAP-16793 states that the assumed cladding oxide The Turkey Point Unit 4 LOCADM calculation thickness for input to LOCADM will be the peak local used the 17% cladding oxide thickness.

oxidation allowed by 10 CFR 50.46, or 17 percent of the cladding wall thickness. The WCAP states that a lower oxidation thickness can be used on a plant-specific basis if that value is justified. The staff does not agree with the flexibility in this approach. Licensees shall assume 17 percent oxidation in the LOCADM analysis.

9. The staff accepts a cladding temperature limit of 8001F as The Turkey Point Unit 4 LOCADM calculation the long-term cooling acceptance basis for GSI-191 used 800'F as the cladding temperature limit.

considerations. Should a licensee calculate a temperature that exceeds this value, cladding strength data must be provided for oxidized or pre-hydrided cladding material that exceeds this temperature.

10. In the response to NRC staff requests for additional The Turkey Point Unit 4 LOCADM calculation information, the PWR Owners Group indicated that if plant- did not use plant-specific refinements for specific refinements are made to the WCAP-16530-NP base chemical product generation, therefore, no model to reduce conservatisms, the LOCADM user shall reduction in the chemical source term is demonstrate that the results still adequately bound chemical present.

product generation. If a licensee uses plant-specific refinements to the WCAP-16530-NP base model that reduce the chemical source term considered in the, downstream analysis, the licensee shall provide a technical justification that demonstrates that the refined chemical source term adequately bounds chemical product generation. This will provide the basis that the reactor vessel deposition calculations are also bounding.

11. WCAP-16793-NP states that the most insulating material The Turkey Point Unit 4 LOCADM calculation that could deposit from post-LOCA coolant impurities would used the deposit thermal conductivity value of be sodium aluminum silicate. WCAP-16793 recommends 0.11 BTU/hr-ft-°F. The Westinghouse that a thermal conductivity of 0.11 BTU/hr-ft-°F be used for LOCADM model listed a default value of 0.2 the sodium aluminum silicate scale and for bounding W/m-K, which is the metric equivalent of 0.11 calculations when there is uncertainty in the type of scale BTU/hr-ft-°F.

that may form. If plant-specific calculations use a less conservative thermal conductivity value for scale (i.e.,

greater than 0.11 BTU/hr-ft-°F), the licensee shall provide a technical justification for the plant-specific thermal conductivity. This justification shall demonstrate why it is not possible to form sodium aluminum silicate or other scales with conductivities below the selected value.

12. WCAP-16793-NP indicates that initial oxide thickness and The Turkey Point Unit 4 LOCADM calculation initial crud thickness could either be plant-specific estimates used 17 percent of the cladding wall based on fuel examinations that are performed or default thickness for peak local oxidation allowed by values in the LOCADM model. Consistent with Conditions 10 CFR 50.46; see item #8 above. The and Limitations item number 8, the default value for oxide default value for the crud thickness used for used for input to LOCADM will be the peak local oxidation input to the LOCADM calculation was 140 allowed by 10 CFR 50.46, or 17 percent of the cladding wall microns, which is a more conservative value thickness. The default value for crud thickness used for than 127 microns.

input to LOCADM is 127 microns, the thickest crud that has been measured at a modern PWR. Licensees using plant- The 140 microns is the bounding crud specific values instead of the WCAP-16793-NP default thickness for all plants provided by values for oxide thickness and crud thickness shall justify Westinghouse.

the plant-specific values. I

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 75 of 78 L&C No. NRC Limitations & Conditions (WCAP-16793-NP Rev. 0) FPL (Turkey Point Unit 4) Response

13. As described in the Conditions and Limitations for WCAP- The Turkey Point Unit 4 LOCADM calculation 16530-NP (ADAMS ML073520891), the aluminum release applied a factor of two to the aluminum rate equation used in WCAP-16530-NP provides a release rate while maintaining the total reasonable fit to the total aluminum release for the 30-day aluminum release to that of the 30 day ICET tests but under-predicts the aluminum concentrations mission time.

during the initial active corrosion portion of the test. To provide more appropriate levels of aluminum for the The methodology for increasing the aluminum LOCADM analysis in the initial days following a LOCA, release rate by a factor of two was provided licensees shall apply a factor of two to the aluminum release in additional guidance to the LOCA as determined by the WCAP-16530-NP spreadsheet, Deposition Model by Westinghouse.

although the total aluminum considered does not need to exceed the total predicted by the WCAP-16530-NP spreadsheet for 30 days. Alternately, licensees may choose to use a different method for determining the aluminum release, but in all cases licensees shall not use a method that under-predicts the aluminum concentrations measured during the initial 15 days of ICET 1.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 76 of 78 Enclosure 3 (Turkey Point Unit 4 Updated Supplemental Response)

NRC Safety Evaluation Report Limitations and Conditions for WCAP 16530-NP Revision 0

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 77 of 78 L&C No. NRC Limitation & Condition (WCAP 16530 NP Rev. 0) FPL (Turkey Point Unit 4) Response A peer review of NRC-sponsored chemical effects testing Not Applicable--This is not a limit or condition.

was performed and a number of technical issues related to GSI-191 chemical effects were raised by the independent peer review panel members (NUREG-1861). The peer review panel and the NRC staff developed a PIRT of technical issues identified by the peer review panel. The NRC staff is working to resolve the technical issues identified in the PIRT. Part of the resolution process includes NRC-sponsored analyses being performed by PNNL. Although the NRC staff has not developed any information related to the PIRT issues resolution that would alter the conclusions of this evaluation, some issues raised by the peer review panel were not completely resolved at the time this evaluation was written. An example of such an issue is the potential influences of organic materials on chemical effects. Therefore, it is possible that additional analysis or other results obtained during the resolution of the remaining peer review panel issues could affect the conclusions in this evaluation. In that event, the NRC staff may modify the SE or take other actions as necessary.

This evaluation does not address TR WCAP-16785-NP, Not Applicable--This is not a limit or condition.

"Evaluation of Additional Inputs to the WCAP-16530-NP FPL used the Pressurized Water Reactor Chemical Model." The NRC staff will provide comments on Owners Group (PWROG) methodology, which WCAP-16785-NP separate from this evaluation. In is in accordance with WCAP-16793-NP, addition, a separate SE will address a related TR, WCAP- Revision 0, to evaluate chemical effects in the 16793-NP, "Evaluation of Long-Term Cooling Considering reactor vessel.

Particulate, Fibrous, and Chemical Debris in the Recirculating Fluid." Chemical effects in the reactor vessel are not addressed in WCAP-16530-NP or in this SE.

Therefore, the approval of this TR does not extend to chemical effects in the reactor vessels.

If a licensee performs strainer head loss tests with The Turkey Point Unit 4 chemical effects surrogate precipitate and applies a time-based pump testing program was performed by PCI which NPSH margin acceptance criteria (i.e., timed precipitate implemented the WCAP 16530-NP to define additions based on topical report model predictions), they the quantities and types of chemical must use an aluminum release rate that does not under- precipitates to be formed in the post-LOCA predict the initial 15 day aluminum concentrations in ICET environment. It was assumed the WCAP 1, although aluminum passivation can be considered 16530-NP has correctly considered the during the latter parts of the ECCS mission time in this aluminum release rate and does not under case. predict the initial 15 day aluminum concentrations. Additionally, since the total quantity of generated precipitants is tested in a 1-2 day test period, the time was conservatively compressed to measure the full effect of chemicals across the screens. All chemical precipitates were qualified in accordance with the WCAP 16530-NP and NRC preferences; the effect of the post-LOCA environment is believed to be bounded in the implemented test protocol.

Turkey Point Unit 4 L-2008-160 Docket No. 50-251 Attachment 2 Page 78 of 78 L&C No. NRC Limitation & Condition (WCAP 16530 NP Rev. 0) FPL (Turkey Point Unit 4) Response For head loss tests in which the objective is to keep Turkey Point Unit 4 did not perform strainer chemical precipitate suspended (e.g., by tank agitation): head loss tests in which the objective is to Sodium aluminum silicate and aluminum oxyhydroxide keep chemical precipitate suspended. All precipitate settling shall be measured within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of the chemical debris generated complied with the time the surrogate will be used and the 1-hour settled settling rates requested by the NRC and was volume shall be 6 ml or greater and within 1.5 ml of the introduced into the flume within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of its freshly prepared surrogate. Calcium phosphate precipitate generation; also see L&C No. 6.

settling shall be measured within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of the time the surrogate will be used and the 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months settled volume shall be 5 ml or greater and within 1.5 ml of the freshly prepared surrogate. Testing shall be conducted such that the surrogate precipitate is introduced in a way to ensure transportation of all material to the test screen.

For head loss testing in which the objective is to settle The Turkey Point Unit 4 chemical effects chemical precipitate and other debris: Aluminum testing program was performed by PCI which containing surrogate precipitate that settles equal to or less tested with the objective to allow settlement of than the 2.2 g/I concentration line shown in Figure 7.6-1 of the chemical precipitates. All chemical debris WCAP-16530-NP (i.e., 1-or 2- hour settlement data on or generated for testing complied with the settling above the line) is acceptable. The settling rate shall be rates requested by the NRC and was measured within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of the time the surrogate introduced into the flume within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of its precipitate will be used. generation.

6. For strainer head loss testing that uses TR WCAP-16530- Turkey Point Unit 4 did not utilize sodium NP sodium aluminum silicate and is performed in a de- aluminum silicate. Instead, PCI utilized ionized water environment, the total amount of sodium aluminum oxyhydroxide for all PCI clients that aluminum silicate added to the test shall account for the specify aluminum oxyhydroxide and/or sodium solubility of sodium aluminum silicate in this environment, aluminum silicate as the chemical debris surrogate.