ML101400507

E-mail Handouts for the 5/20/2010 Kewaunee Public Meeting

ML101400507
Person / Time
Site:	Kewaunee
Issue date:	05/19/2010
From:	Tam P NRC/NRR/DORL/LCPAB, Plant Licensing Branch III
To:	Collins M, John Repetto NRC/OIS/IRSD
References
GL-04-002, TAC MC4691
Download: ML101400507 (261)

Text

Collins, Michael From: Tam, Peter Sent: Wednesday, May 19, 2010 4:26 PM To: Collins, Michael; Repetto, John

Subject:

Handouts for the 5/20/10 Kewaunee public meeting Mike:

I just brought to your office the complete set of handouts for the 5/20/10 Kewaunee public meeting. Please have the whole set scanned and entered into the package indicated below in ADAMS, and made publicly available. Use the following information for the profile:

Availability: Public Docket No.: 05000305 License No.: DPR-43 Reference No.: TAC MC4691 Author: Gadzala, J Author Affiliation: Dominion Energy Kewaunee, Inc.

Package Accession No.: ML101380268 Release date: 5121/2010

Contact:

Peter Tam Sensitivity: Non-sensitive g'ete S. gam Senior Project Manager (for Kewaunee and Monticello)

Plant Licensing Branch Il1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Tel. 301-415-1451 1

U. S. Nuclear Regulatory Commission Serial No.10-025 Attention: Document Control Desk LIC/JG RO Washington, DC 20555-0001 Docket No. 50-305 License No. DPR-43 DOMINION ENERGY KEWAUNEE, INC.

KEWAUNEE POWER STATION RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING NRC GENERIC LETTER 2004-02 The Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation during Design BasiL Accidents at Pressurized-WaterReactors, on January 11, 2008. This GL was issued to resolve NRC Generic Safety Issue (GSI) 191, Assessment of Debris Accumulation on PWR Sump Performance. GL 2004-02 requested 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 letter and, if appropriate, take additional actions to ensure system function.

Dominion Energy Kewaunee (DEK) responded to GL 2004-02 by letters dated March 7, 2005, July 6, 2005, September 1, 2005, February 29, 2008, and May 21, 2008. By letter dated December 18, 2008, additional updates were provided following resolution of the topics of downstream effects and chemical effects.

On August 14, 2009, the NRC staff transmitted a request for additional information (RAI)

(Reference 1) regarding the response to GL 2004-02 for Kewaunee Power Station (KPS). Following a telephone conference between DEK and NRC staff on September 15, 2009, revised Questions 5, 6, 7, and 12 to the RAI (Reference 2) were received from NRC on October 14, 2009.

Several teleconferences were held between DEK and NRC staff between September 2009 and March 2010 to discuss DEK's response to the RAIs. Subsequently, on March 30, 2010, DEK verbally informed NRC staff of our intent to remove certain fibrous materials from the Containment building to ensure the recirculation strainer head los"&.

tests already performed for Kewaunee remain bounding. A summary of the planned changes and an implementation schedule are presented in Attachment 1 to this letter.

The staff's questions and associated DEK responses are provided in Attachment 2 to this letter.

DRAFT April 23, 2010

Serial No.10-025 Page 2 of 4 If you have any questions regarding this response, please contact Mr. Jack Gadzala at (920) 388-8604.

Sincerely, J. Alan Price Vice President - Nuclear Engineering COMMONWEALTH OF VIRGINIA

)

COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mr. J. Alan Price, who is Vice President - Nuclear Engineering of Dominion Energy Kewaunee, Inc. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that Company, and that the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this day of _2010.

My Commission Expires:

Notary Public DRAFT April 23, 2010

Serial No.10-025 Page 3 of 4 Attachments:

Attachment 1- Summary of Planned Changes and Implementation Schedule Attachment 2 - Response to Request for Additional Information: Generic Letter 2004-02 Attachment 3 - List of Enclosures Commitments made in this letter:

1. Fibrous insulation will be removed from components in the RCS loop vaults as follows.

a. The fibrous insulation (TempMat) on the pressurizer surge line pipe whip restraints will be removed and replaced with a nonfibrous material.

b. The fibrous insulation on the service water piping that passes through the top of the "B" reactor coolant pump vault will be removed and replaced with a nonfibrous material.

2. The JM Thermobestos insulation (calcium silicate insulation with asbestos fibers) in Vault A will be secured with stainless steel banding, similar to that performed in Vault B (opposite train) to enable use of a Zone of Influence (ZOI) size equal to 5.45D.

3. Fibrous material remaining in containment will be assumed to be fines and subject to transport to the recirculation sump strainer.

4. For analysis purposes, 15% of the fibrous fines, along with 15% of the Thermobestos particulate and qualified coatings, will be assumed to transport to the inactive sump below the reactor vessel (Sump C) during the sump fill prior to the start of recirculation.

5. The allowable quantity of latent debris (dirt, dust) in containment will be limited to 61 Ibm to prevent formation of a thin bed of fiber on the recirculation sump strainer when combined with the remaining fiber in containment.

6. A thin bed of fiber on the recirculation sump strainer will be defined as greater than or equal to 1/16 inch.

DRAFT April 23, 2010

Serial No.10-025 Page 4 of 4

References:

1. Letter from Peter S. Tam (NRC) to David A. Heacock (DEK), "Kewaunee Power Station - Request for Additional Information Regarding Response to Generic Letter 2004-02 (TAC No. MC4691)", dated August 14, 2009.

2. Email from Peter S. Tam (NRC) to Jack Gadzala, Thomas Breene and Craig Sly (DEK), "Kewaunee - Revised Questions 5, 6, 7, and 12 of the 8/14/09 RAI (TAC MC4691)", dated October 14, 2009.

cc: Regional Administrator, Region III U. S. Nuclear Regulatory Commission 2443 Warrenville Road Suite 210 Lisle, IL 60532-4352 Mr. P. S. Tam Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 08-H4A 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Kewaunee Power Station DRAFT April 23, 2010

ATTACHMENT I

SUMMARY

OF PLANNED CHANGES AND IMPLEMENTATION SCHEDULE DOMINION ENERGY KEWAUNEE, INC.

KEWAUNEE POWER STATION DRAFT April 23, 2010

Serial No. 08-0017A Attachment 1 Page 1 of 7

SUMMARY

OF PLANNED CHANGES AND IMPLEMENTATION SCHEDULE Following a series of teleconferences between Dominion Energy Kewaunee (DEK) and NRC staff regarding the resolution of Generic Letter (GL) 2004-02, DEK has elected to remove fibrous insulation material from the containment building. The insulation removal, along with other specified changes outlined below, will ensure the fibrous materials remaining in the containment will not form of a thin bed of fiber on the recirculation strainer as a result of post-LOCA generated debris. A thin bed of fiber on the recirculation sump strainer, along with particulate and chemical debris, has the potential to cause high head loss across the strainer and challenge the operation of the containment sump recirculation system.

The changes outlined below will address the remaining debris generation and testing concerns identified by NRC staff and will prevent the need to retest the Kewaunee Power Station (KPS) recirculation sump strainer system. The planned changes and the impacts of those changes are presented below, along with an implementation schedule.

A.

SUMMARY

OF PLANNED CHANGES Debris Generation and Transport

1. Fibrous insulation will be removed from components in the RCS loop vaults as follows.

a. The fibrous insulation (TempMat) on the pressurizer surge line pipe whip restraints will be removed and replaced with a nonfibrous material.

b. The fibrous insulation on the service water piping that passes through the top of the "B" reactor coolant pump vault will be removed and replaced with a nonfibrous material.

2. The JM Thermobestos insulation (calcium silicate insulation with asbestos fibers) in Vault A will be secured with stainless steel banding, similar to that performed in Vault B (opposite train) to enable use of a Zone of Influence (ZOI) size equal to 5.45D.

3. Fibrous material remaining in containment will be assumed to be fines and subject to transport to the recirculation sump strainer.

4. For analysis purposes, 15% of the fibrous fines, along with 15% of the Thermobestos particulate and qualified coatings, will be assumed to transport to the inactive sump below the reactor vessel (Sump C) during the sump fill prior to the start of recirculation.

DRAFT April 23, 2010

Serial No. 08-0017A Attachment 1 Page 2 of 7 Allowable Latent Debris Quantity to Prevent Thin Bed Effect

5. The allowable quantity of latent debris (dirt, dust) in containment will be limited to 61 Ibm to prevent formation of a thin bed of fiber on the recirculation sump strainer when combined with the remaining fiber in containment.

6. A thin bed of fiber on the recirculation sump strainer will be defined as greater than or equal to 1/16 inch.

B. ISSUE RESOLUTION AS A RESULT OF THE PLANNED CHANGES The goal of the fibrous insulation removal and Thermobestos insulation banding activities, in combination with revising the maximum allowed latent debris in Containment, will reduce the overall quantity of fibrous material that could be generated by a LOCA such that a thin or thick bed of fiber will not form on the recirculation strainer.

Eliminating the potential for a thick or thin bed of fiber will address the NRC concerns regarding PCI strainer testing performed for Kewaunee, such as, but not limited to, the quantity and preparation of fibrous material for testing and the pre-test transport evaluation (e.g., TempMat tumbling velocity applied, computational fluid dynamics model results at the wall opening near the center of the recirculation strainer).

Debris Generation and Transport Removal of the fibrous material from the pressurizer surge line pipe whip restraints and the Service Water piping in RCS Loop B equipment vaults will eliminate the majority of the fibrous material in the limiting postulated LOCA break locations.

The JM Thermobestos insulation (calcium silicate insulation with asbestos fibers) on the steam generator blowdown piping in Vault A will be secured with stainless steel banding, similar to that performed in Vault B (opposite train) to enable use of a ZOI size equal to 5.45D. Additional locations outside the RCS Loop Vaults may also be banded if deemed necessary to minimize the ZOI size for other non-limiting break locations. The use of banding, in addition to the current insulation fasteners which consists of a combination of bands, rivets and screws, ensures the calcium silicate lagging configuration is equal to or better than Ontario Power Generation test configuration referenced in NEI 04-07 (Section 9, Reference 7) that resulted in a ZOI size determination of 5.45D. The quantity of Thermobestos material generated in RCS Loop A Vaults following banding activities, is equal to DRAFT April 23, 2010

Serial No. 08-0017A Attachment 1 Page 3 of 7 3.7 ft3 , whereas 10% of this material is fibrous (0.37 ft3 ) and 90% is particulate (see response to RAI Question 2). The quantity of Thermobestos material in the RCS Loop B Vaults is 2.3 ft3 (0.23 ft3 fibrous).

Due to the revised debris inventory following the changes noted above, postulated break locations were re-evaluated to determine if the location of the limiting debris generating break has changed. Table B-1 depicts the review of the postulated break locations and the debris generation for all materials. This review determined the limiting break remains the RCS Loop B hot leg break at the steam generator.

The new debris inventory will assume all of the noted fibrous material as being Fines (no Smalls or Larges). This is conservative in that all of the fibrous material noted will be assumed to transport to the recirculation strainer.

However, the transport of fiber Fines, Thermobestos particulate and qualified coatings will credit transport of 15% of this material to the inactive sump during the recirculation fill prior to the start of recirculation. The inactive sump, Sump C, is located beneath the reactor vessel. The volume of water in Sump C below the entry point into the sump is 3,500 ft3 (see response to RAI Question 34) which is

> 15% of the recirculation sump water volume at the onset of recirculation (22,550 ft3 ) and supports use of the 15% value. Unqualified coatings will not be assumed to transport to Sump C as it is plausible that Sump C would fill prior to debris generation and transport of this debris type.

Table B-1 indicates the limiting postulated RCS break that generates the most fibrous debris and detrimental mixture and quantity of debris is the RCS Loop B hot leg break at the steam generator. A break at the RCS Loop A hot leg break would create a larger quantity of particulate debris, but there would be less fiber on the strainer to filter the particulate. For either limiting break, the total quantity of fibrous debris will be limited to prevent creating a thin bed of fiber on the recirculation strainer.

DRAFT April 23, 2010

Serial No. 08-0017A Attachment 1 Page 4 of 7 TABLE B-i: BREAK CASES THERMO- THERMO- CERA- LATENT UNQUALIFIED MK EAK BESTOS BESTOS BLANKET FIBER(14) COATINGS QUALII FIBER(1,2) PARTIC.(1,2) FIBER (1) COATIN,

)opA 0 ft3 0 ft3 0 ft 3 0 ft 3 3.82 ft 3 3.91 ft 3 Note

)op A 0 ft3 0 ft3 0 ft 3 0 ft 3 3.82 ft 3 3.91 ft 3 Note

.d. Leg

)op A 0.32 ft 3 2.86 ft3 0 ft3 0 ft 3 3.82 ft3 3.91 ft 3 Note

)op B 0 ft 3 0 ft3 0 ft3 0 ft 3 3.82 ft 3.91 ft3 0.45

)op B 0 0 ft3 0.48 ft 3 0 ft 3 3.82 ft3 3.91 ft 3 0.53

!d. Leg of B .20 1.7 ft 048 ft Oft3 3.Y82 ft3 3.91 f 3 . 10 sel Cold 0ft3 0 ft3 0 ft3 0.43 ft3 3.82 ft3 3.91 ft 3 Note sel 0 ft3 0 ft3 0 ft3 0.22 W 3.82 W 3.91 ft3 Note Hot Leg (1) Credits 15% of material as transported to inactive Sump C (2) Thermobestos material, calcium silicate with asbestos fibers, 10% fiber, 90% particulate (3) Pressurizer heater cables fibrous insulation material (4) Based on 61 Ibm total allowable latent debris (see discussion below) (3.323 ft3

• 1.15)

(5) Not calculated, however values are assumed to be equivalent to Loop B data due to mirror image coated structures (6) Not calculated, however due to the location of this break being mainly contained within the reactor vessel shield wall, the majority of the debris generated, including failed qualified coatings, would be deposited into the inactive sump below the reactor vessel Allowable Latent Debris Quantity to Prevent Thin Bed Effect A reduction in the quantity of allowable latent debris (dirt, dust) in Containment will prevent the formation of a thin bed of fiber on the recirculation strainer, when combined with other fibrous material remaining in the postulated break locations.

A new limit of 61 Ibm will be set for the maximum allowable latent debris in Containment.

Historically, a bed of fiber equal to 1/8 inch was believed to cause the most detrimental strainer head loss when particulate is present in the debris mix.

Industry strainer head loss testing has identified that higher head losses can occur at lesser fiber thicknesses, especially when calcium silicate is present in the debris mix (NRC Staff Review Guidance Regarding Generic Letter 2004-02 Closure in the Area of Strainer Head Loss and Vortexing, dated March 2008).

Kewaunee's recirculation strainer has an effective surface area of 768.7 ft2 . A maximum fiber bed thickness of 1/16 inch is selected to ensure high head loss DRAFT April 23, 2010

Serial No. 08-0017A Attachment 1 Page 5 of 7 does not occur from a thin bed of fiber filtering particulate debris. The source of fiber is from latent debris and the small quantities of fibrous materials noted in Table B-1 above. The quantity of calcium silicate particulate debris in Kewaunee's Containment is low (1.8 ft3 in the limiting break location with the inactive sump credited). The Containment recirculation sump volume at the onset of recirculation is 22,550 ft3 . This is the volume at the minimum sump water level of 43.44 inches (see RAI Question 32 for further detail). This results in a calcium silicate volume concentration of 7.9 E-05, which is sufficiently low that it would be expected to have a negligible impact on the strainer head loss.

Using the fibrous debris load from the limiting RCS hot leg break at the steam generator, and using a maximum fiber bed thickness of 1/16 inch, the maximum quantity of latent debris is determined to be 61 Ibm.

TABLE B-2: STRAINER BED THICKNESS FOR 768.7 FT2 STRAINER STRAINER FIBER BED STRICNER S 1/8 IN 1/10 IN 1/12 IN 1/14 IN .i/1,6i IN",

THICKNESS Bed Thickness IN 0.125 0.100 0.083 0.071 0.063 Bed Thickness FT 0.010 0.008 0.007 0.006 0.005 Bed Volume FT3 8.007 6.406 5.338 4.575 4.003 Non-Latent Fiber (1) FT3 0.680 0.680 0.680 0.680 0.680 Allowable Latent Fiber FT3 7.327 5.726 4.658 3.895 3.323 Allowable Latent Fiber (2) LBM 17.585 13.741 11.179 9.349 7.976 Allowable Latent Debris LBM 117.232 91.609 74.528 62.327 53.176 44059'~le 7LL

,-BM 134.816 105.351 85.707 71.676 61.152"'

crdtiniog nja cc______44_MIA____)

(1) Thermobestos, Okotherm (2) 2.4 lbm/ft3 (3) Assumes 100% of generated fibrous material is placed on the strainer surface DRAFT April 23, 2010

Serial No. 08-0017A Attachment 1 Page 6 of 7 Revised Debris Load - Comparison to Strainer Flume Tests The results of the strainer head loss tests are presented in Enclosures F-2, 1-2 and 1-3 in this letter. The minimum specified quantity of fine fiber and other debris materials used during the tests is presented in Table B-3 below, in comparison to the revised debris load for the limiting break location.

" Small fiber pieces (Smalls) are not used in the comparison since very few pieces were observed to have transported to the recirculation strainer when the test flume was drained down (see Enclosure 1-4) and the new debris inventory will not include fibrous material larger than Fines.

" TempMat Fines are not used in the comparison since NRC staff has questioned the debris preparation used for the tests (Fines were questioned as not being prepared with sufficient individual fibers).

TABLE B-3: TESTED CONFIGURATION VS. LIMITING BREAK LIMITING BREAK DEBRIS U/M TEST 3 TEST 1 REVISED (ENCL. I-2) (ENCL. I-3) DEBRIS LOAD Thermobestos Fiber Fines FT3 0 0 0.20 Okotherm Fiber Fines FT3 0.23 0.23 0.48 Latent Fiber Fines rFT- 4.69 (2) 4.69 (2) 3.82 Owens Corning Pipe Cover FT 3 0.44 0.88 0 Fines Thermobestos Particulate FT 3 0.49 0.49 1.78 Latent Particulate LBM 85 100 51.82 85 100(85% of 61 Ibm)

Zinc Coating Particulate FT' 0.84 0.84 Epoxy/Enamel Coating FT3 4.68 4.68 5.00 Particulate Epoxy Coating Chips FT3 0.09 0.09 Chemical Precipitant LBM 12.51 25.02 12.51 (100% of design) (200% of design)

(1) Maximum allowable strainer head loss is 10 ft of water (2) Quantity added AFTER the pump was started The data shown in Table B-3 indicates the large scale strainer head loss flume tests conducted by PCI at the Alden Research Laboratory facility bounds the revised debris inventory.

DRAFT April 23, 2010

Serial No. 08-0017A Attachment 1 Page 7 of 7

" The quantity of fibrous Fines in the revised debris inventory is bounded by the quantity used in the flume tests, and includes only those fiber Fines added after the recirculation pump was started.

" The method of debris preparation for the Fines used in the test shown in Table B-4 were not questioned by NRC staff (only TempMat Fines preparation was questioned).

• A thin bed of fiber was not formed on the recirculation strainer during the tests as can be seen from the flume draindown photos that show bare strainer surfaces (Enclosure 1-4) and by the low strainer head loss achieved during the tests, even with 200% chemical debris addition to the test flume.

• There was sufficient fibrous Fines added to the test flume to create a potential bed thickness between 1/12 and 1/10 inch.

This information, along with the responses to the individual RAI questions in /

Attachment 2 to this letter, provide assurance that the recirculation strainer flume tests performed by PCI for Kewaunee remain accurate and bounding and negate the need for retest.

C. IMPLEMENTATION SCHEDULE The changes will be implemented no later than two refueling outages following the current operating cycle's refueling outage. This will afford the time necessary to conduct additional plant walkdowns, perform design activities, order materials and plan and perform the installation to minimize personnel dose and the impact on plant operations.

Following implementation of these changes, the Kewaunee Updated Safety Analysis Report will be updated to reflect the revised recirculation system design basis, including the maximum allowable fibrous debris in Containment.

DRAFT April 23, 2010

ATTACHMENT 2 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION GENERIC LETTER 2004-02 DOMINION ENERGY KEWAUNEE, INC.

KEWAUNEE POWER STATION DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 1 of 77 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION KEWAUNEE POWER STATION Dominion Energy Kewaunee (DEK) responded to GL 2004-02 by letters dated March 7, 2005, July 6, 2005, September 1, 2005, February 29, 2008, May 21, 2008, and December 18, 2008. On August 14, 2009, the NRC staff transmitted a request for additional information (RAI) (Reference 1) regarding the response to GL 2004-02 for Kewaunee Power Station (KPS). Revised Questions 5, 6, 7, and 12 to the RAI (Reference 2) were received from NRC on October 14, 2009.

The staff's questions and associated DEK responses are provided below. One additional clarification was verbally requested during a teleconference with NRC staff on March 4, 2010.

Clarification Item - Zone of Influence Size for Inorganic Zinc Coatings NRC Request Please clarify that the Zone of Influence (ZOI) size for qualified inorganic zinc coatings remains as 10D.

Response

The DEK response dated February 29, 2008 (refer to Tables 3.B-2 and 3.H-2 in response), indicates that KPS implemented a reduced ZOI equal to 4D for the epoxy coating systems listed in the table below. This ZOI reduction was based on evaluating Kewaunee's use of Florida Power & Light's coating test report, JOGAR-06-001, Revision 0.

COATING SYSTEMS PRIMER / TOPCOAT(S)

• Carboline 195 / Phenoline 305 Concrete

• Phenoline 305 / Carboline 195 / Phenoline 305 0 Phenoline 305 / Phenoline 305 Steel 0 Carboline Carboguard 890 / Carboguard 890

• Carboline Carbozinc 11 / Phenoline 305 A ZOI equal to 1OD is applied to all other qualified coatings not shown in the table above.

In addition, 100% of unqualified coatings are assumed to fail.

DRAFT April 23, 2010

Serial No.10-025 Attachment,£ Page 2 of 77 A. Break Selection NRC Question 1 Please provide the following additional information regarding the break selection evaluation:

a. the systematic method used in the break selection evaluation,

b. the specific locations of the selected breaks along their respective piping component,

c. specification of which reactor coolant loop contains the pressurizer,

d. justification for not having a reactor vessel nozzle break in the list of break selections.

Response

The systematic method used to determine Kewaunee's break selection was provided in our response dated September 1, 2005 (Attachment 1, pg 6 of 19) and February 29, 2008 (Attachment, pages 3 and 4 of 42).

Three reactor coolant system (RCS) breaks in Loop (Train) B were evaluated. Those breaks were: RCS hot leg break at the steam generator, RCS cold leg break at the reactor coolant pump (RCP), and RCS intermediate leg break at the steam generator.

The RCS hot leg break at the steam generator was determined to be the limiting break.

RCS Loop B contains the pressurizer and therefore, the RCS breaks in Loop B result in the largest types and/or quantity of debris.

Due to the large zone of influence (ZOI) for the debris types present in these areas (see Enclosure A), additional breaks on the RCS loops were not analyzed as the debris source term would not change. The insulation debris materials in RCS Loop B include:

• Reflective metal insulation (RMI) (ZOI 28.6D)

" TempMat encased in 24 gauge stainless steel panels (ZOI 17D)

" Thermobestos (calcium silicate with asbestos fibers) (ZOI 5.45D)

" Fiberglass pipe cover (ZOI 17D)

• Pressurizer heater fibrous cable insulation (ZOI 17D)

A ZOI of 17D or larger encompasses the entire Loop B vaults/compartments (includes reactor coolant pump, steam generator, and pressurizer compartments - see Enclosure A). The limiting break, RCS hot leg at the steam generator, results in the most detrimental mixture of insulation debris. It creates additional debris due to its location near the pressurizer, such as, RMI debris from the pressurizer and pressurizerr heater fibrous cable insulation debris.

The RCS break at a reactor vessel nozzle was initially not analyzed as a limiting debris generation location due to its location outside the RCS Loop B vaults. The nozzles are DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 3 of 77 located within the reactor vessel shield wall, shielded overhead by "sand plugs" each weighing 3,800 lbs. This break will not result in the most detrimental debris generation.

The reactor vessel nozzles are insulated with reflective metal insulation (RMI). Reactor vessel nozzle pipe restraints were installed in 1980 in the shield wall penetrations between the RCS Loop vaults and the reactor vessel sump. The restraints were insulated with 0.032 inch thick stainless steel type 304 sheet metal panels encapsulating 3" thick Johns Manville cerablanket. The volume of cerablanket insulation in the RCS Loop B hot leg shield wall penetration is estimated at 0.26 ft3 . The volume of cerablanket insulation in the RCS Loop B cold leg shield wall penetration is estimated at 0.5 ft 3 .

Debris generated due to a RCS pipe break at the reactor vessel nozzle would cause the RMI to blow down to the bottom of inactive Sump C below the reactor vessel. Some small pieces of RMI and the cerablanket material would blow into the RCS Loop B vault compartment and could potentially wash down to the Containment sump (basement) by blowdown or Containment Spray washdown. However, a break at this location would not produce any other fibrous debris, other than latent fiber, and would result in minimal coating debris. Further, the debris that would blow down to Sump C below the reactor vessel would stay in this location and not transport to the recirculation strainer as the .

water in this location does not freely recirculate with the Containment basement sump pool. A RCS pipe break in the RCS Loop vault/compartment would blow the restraint insulation in the shield wall penetration(s) into the void below the reactor vessel.

Pictorial views of the analyzed breaks are provided in Enclosure A.

As stated in Attachment 1, Kewaunee plans to remove the fibrous TempMat material from the pressurizer surge line pipe whip restraints and the fibrous insulation on the service water piping in Vault B. Due to these changes, the postulated break locations were re-evaluated, including the reactor vessel nozzle break. The limiting break remains as a RCS Loop B hot leg break at the steam generator. Refer to Attachment 1, Table B-1.

B/C. Debris Generation/Zone of Influence/Characteristics NRC Question 2 Please justify adopting the safety evaluation-approved 5.45D zone of influence for calcium silicate insulation for the Thermobestos installed at Kewaunee by comparing the respective jacketing/banding systems to ensure that the Thermobestos is as well-protected as the Ontario Power Generation-tested calcium silicate insulation.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 4 of 77,

Response

The calcium silicate insulation (Johns Manville Thermobestos) on the steam generator blowdown lines in Containment was judged to be similar to the calcium silicate insulation tested by Ontario Power Generation (NEI 04-07, Vol 1, Table 3-1). The calcium silicate insulation tested by Ontario Power Generation was clad with 0.016" aluminum jacketing with stainless steel bands (Ontario Hydro Report N-REP-34320-10000-ROO). Kewaunee's calcium silicate insulation is wrapped in stainless steel (SS) jacketing, 0.010" minimum thickness, and is fastened with a combination of SS rivets, SS bands and SS screws.

Type 304 stainless steel jacket on the KPS steam generator blowdown lines has more strength than aluminum jacket. The tensile strength of aluminum alloy 1100, as cited in the Ontario Power Generation Report N-REP-34320-1 0000-ROO, "Jet Impact Tests -

Preliminary Results and Their Applications," Ontario Power Generation, April 2001, is 13,000 psi. The tensile strength of Type 304 stainless steel is 73,200 psi. The Ontario Power Generation (OPG) test utilized /2 inch 0.02 inch thickness stainless steel bands to fasten the jacketing. Kewaunee's insulation jacketing is fastened with a combination of SS rivets, SS bands and SS screws. In lieu of evaluating the strength of the OPG configuration against Kewaunee's various configurations, Kewaunee added 1/2" SS bands, 0.02 inch thickness, 6 inches on center on the Thermobestos insulation in the limiting debris generation break locations (Vault B, RCS Loop B). This change ensures Kewaunee's insulation configuration is bounded by the OPG test configuration. As indicated in Attachment 1 to this letter, the Thermobestos insulation in Vault A, RCS Loop A, will also be banded to utilize a ZOI of 5.45D at this location as well.

Additional Verbal NRC Request Provide the basis for assuming Thermobestos is 10% fibrous.

Response

The Johns Manville Thermobestos material installed at KPS is assumed to be 10%

fibrous material. Material specification datasheets are not available for this material as it is no longer made and could not be provided by the vendor. Consequently, the material is assumed to be similar to a current Johns Manville product, Thermo-1 2, calcium silicate insulation with cellulose fiber. Thermo-12 has less than10% fibrous material as indicated on the Material Safety Datasheet for this product (Enclosure A-i).

NRC Question 3 Please describe the repairs that were made to the calcium silicate (Thermobestos) and fiberglass insulation systems that justify reducing the amounts of debris generated by these two insulation types. State the zones of influence used for these materials in the updated debris generation evaluation. Provide the bases and assumptions for the DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 5 of 7,7 bases for the zones of influence if they differ from those in the staff safety evaluation (SE) on the NEI Guidance Report 04-07.

Response

As reported in our February 28, 2009 letter, jacketed calcium silicate (Thermobestos) insulation that could become submerged post-accident was repaired to eliminate gaps in the jacketing. The location of this insulation is on the steam generator blowdown piping in the Containment basement elevation. It is not in a large break loss of coolant accident (LOCA) worst case debris-generating zone of influence (not inside the RCS Loop Vaults), therefore, the insulation is not counted in the debris source term. To ensure the insulation remains in place while submerged and does not create calcium silicate insulation debris in the recirculation pool, the gaps in the insulation jacketing exposing the calcium silicate insulation were closed by adding, adjusting or replacing the jacketing, and bands and rivets, as required.

Repairs were also made to jacketed fiberglass insulation on the upper elevation of Containment, on the service water lines that supply the reactor vessel shroud cooling coils. This insulation is located above and to the south of the reactor vessel. This insulation is only subject to Containment Spray impingement. It is not in a debris-generating zone of influence. The insulation in this location was identified as having many dents and gaps in the 0.010 inch thick stainless steel jacketing that exposed the fiberglass material underneath. Consequently, a work order was implemented that replaced entire sections of the insulation and jacketing to ensure there would be no gaps in the jacketing that could allow the release of individual fibers into the refueling cavity pool when wetted by Containment Spray.

The repaired insulation is not within the scope of insulation planned for removal described in Attachment 1 because it is not in a worst case break location for debris generation.

NRC Question 4 Please verify that all latent debris is assumed to be Fines or provide a justification for any different classification. Specify separately the amount of latent particulate and latent fiber assumed in the evaluation.

Response

All KPS latent debris is assumed to be Fines.

Debris is assumed to be 15% fibrous debris and 85% particulate debris (ref. February 29, 2008 response; Section 3.D, Attachment pg 9 of 42) in accordance with NEI 04-07.,

The latent fiber surrogate selected for strainer flume testing was NUKON processed through a shredder. The latent particulate selected for strainer flume testing was the DRAFTApril 23, 2010

Serial No.10-025 Attachment 2 Page 6 of 77 Performance Contracting Incorporated (PCI) Pressurized Water Reactor (PWR) Dirt Mix. PWR Dirt Mix consists of various sizes of silica sands, ranging from < 75 microns to 2000 microns.

Kewaunee's GSI-191 analyses currently assume a total of 100 Ibm latent debris in Containment, however, as noted in Attachment 1, this value will be reduced to 61 Ibm.

The quantity of latent debris used in Kewaunee's large scale flume testing was 100 Ibm (in the design basis case, Test 3) and 115 Ibm (in the supplemental design basis case, Test 9). See also the response to Questions 8 and F.19.c.ii.

NRC Revised Questions 5, 6, 7, and 12 Please provide the following information regarding debris generation, debris transport, and erosion of debris so that the NRC staff can verify that the amounts and size distribution of debris added to the strainer test were appropriate. Please provide this information for fiberglass, TempMat, and Thermobestos.

a. The amount of each debris type generated by the limiting break(s), including the size categorization of the debris as it is initially generated by the LOCA blowdown.

Include the bases for this information, such as approved guidance or test data.

b. The amounts of TempMat, fiberglass pipe cover, and Thermobestos that are considered to erode into fine debris over the entire sump mission time and the basis for the amounts provided. Include information regarding how the initial size distribution of the debris affected the erosion results for each type of debris.

c. Describe how debris that was considered to reach the strainer by the transport calculation and was added to the head loss test flume, but settled prior to reaching the strainer, was treated with respect to erosion. Did the strainer test include a sufficient quantity of fine debris to account for this source? Debris of interest includes Thermobestos, fiberglass, and TempMat. If a sufficient quantity of fine debris to account for the eroded Fines from these components was not added to the test, provide a justification for not doing so or show that the test was not affected non-conservatively by this issue.

d. The amount of each debris type added to the head loss test broken down into the size components fine, small, large, intact. Please include a description of what each debris component represents.

e. The scaling factor used during strainer testing and the basis for this factor.

Response

As noted in Attachment 1 to this letter, Kewaunee will remove the TempMat insulation from the pressurizer surge line pipe whip restraints and will remove the fiberglass pipe cover from the Service Water piping in the RCS Loop B Vault. Following these two DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 7 of 77 modifications, there will not be any TempMat or fiberglass pipe cover in the limiting break locations, a RCS hot leg break in either RCS Loop. Therefore, only Thermobestos material will be addressed in this RAI response.

The quantity of Thermobestos material generated by the limiting breaks, a RCS hot leg break at either RCS Loop A or RCS Loop B, and the quantity of material placed in the large scale strainer flume tests is addressed in Attachment 1, Tables B-1 and B-3. For either limiting break location, there will be insufficient fibrous material generated to create a thin bed of fiber on the strainer, that when filtering particulate, would result in the strainer head loss exceeding the maximum allowable loss of 10 ft of water.

The ZOI size used for Thermobestos material, 5.45D, is addressed in response to Question 2, and in Attachment 1 to this letter.

The fibrous portion of the Thermobestos material will be considered as Fine fiber, therefore, erosion of this material is no longer applicable.

The surrogate materials used during the large scale flume tests were:

o 10% fibrous portion: TempMat Smalls - this material should have been Fines and therefore, is not credited in Attachment 1, Table B-3.

o 90% particulate portion: Pulverized calcium silicate powder. A photograph of, adding pulverized calcium silicate powder to the test flume can be found in Enclosure B.

The 2008 large scale flume tests were performed with a 7.129% scaling factor. One full-sized strainer module supplied from Kewaunee's inventory was used in the large scale flume tests. The strainer module has a surface area of 54.8 ft2 when fully submerged, as it was during the tests. Kewaunee's installed strainer has 14 modules with a total surface area of 768.7 ft2. Therefore, the test strainer was 7.129 percent of the size of the installed strainer (54.8 / 768.7) and the debris load for the test was scaled to place 7.129% of the specified material* in the flume. (*Specified material was debris quantity determined to transport to the strainer, plus margin.)

D. Latent debris NRC Question 8 The staff noted that the licensee provided estimates of the mass of latent fiber and particulate. However, only a brief description of the methodology used to estimate the quantity of the latent debris was provided. The staff determined that the methodology was not presented in sufficient detail to judge its adequacy and conservatism. Similarly the staff noted that although the licensee provided quantitative estimates of the area of tapes, tags, signs and stickers, the procedure used was described insufficiently to judge DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 8 of 77 the adequacy and conservatism of the evaluation. The staff also noted that latent debris quantity (11.3 Ibm) is the lowest measured latent debris quantity of any pressurized-water reactor plant (approximately 1 / 1 0 th the median value), even though the Containment sampling was performed during a relatively dirty condition with work in progress. The licensee stated that its strainer head loss analysis and testing assume 100 Ibm of latent debris, substantially greater than the 11.3 Ibm measured but staff notes, that many plants (including some with low amounts of fibrous and/or particulate insulation), have measured more than 100 Ibm of latent debris in Containment, so staff needs to have confidence that the licensee's sampling method is sufficiently accurate that the 100 Ibm assumed for testing is conservative. Therefore, please describe the surfaces where samples were collected and the number of samples per surface. Please justify that the sample locations were representative of floors, walls, ductwork and equipment surfaces where latent debris could collect. Please summarize the extrapolation/statistical method used to estimate the total latent debris quantity in Containment.

Response

Kewaunee is a relatively small PWR with a low latent debris load. The Containment parameters are as follows:

• 597 MWe

• 105 ft inside diameter

• 192 ft height - basement floor elevation to dome roof

• 1,320,000 ft3 free volume 0 Four floor elevations 0 Reflective metal insulation (RMI) plant

• Coated surfaces The following latent debris sampling and evaluation procedures were forwarded to the Staff for their review on September 16, 2009 (forwarded by e-mail):

Note: The following procedures were superseded by Dominion fleet procedure CM-AA-CRS-101, Revision 2, and calculation Cl1928, Revision 0, in February2010. See response below.

• NEP-04.23, Containment Latent Debris Sample Collection, Rev. 2

• NEP-04.22, Containment Latent Debris Sampling Evaluation, Rev. 2 Initial latent debris sampling and evaluation was performed in October 2004. The evaluation quantified 11.3 Ibm latent debris. Fifteen samples were collected. The first three samples were discarded as "practice samples" and one sample with weight loss was not used. The evaluation was based on the eleven remaining samples. With a small number of samples and using statistical analysis, this resulted in a high assumed debris load for some categories. Example:

2 Floor Surfaces: Sample 12 = 0.021 g/ft DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 9 of 77 2

Sample 13 = 0.003 g/ft Sample 4 = 0.187 g/ft2 Mean Debris Loading = 0.181 g/ft2 The next sample collection and evaluation will be conducted during the Spring 2011 Refueling Outage.

During the initial sample collection and evaluation, samples were collected from floors, ventilation ductwork, the Containment liner and walls. Table 8-1 displays the data collection and evaluation summary:

Table 8-1 Sample Debris Area Loading 90% Conf. Total Area Total Identification (g) (ft2) (g/ ft2) Upper Limit Evaluated Debris (g/ft2) (ft2) (Ibs)

Floors Sample 12 0.7 33 0.021 Sample 13 0.15 56 0.003 0.181 18,575 7.4 Sample 4 1.8 9.625 0.187 Containment Liner Sample 7 0.1 51.8

__________ _ _ 0.002

__ __0.006__ 0.006 __ 41,240_ 0.6 Sample 9 0.3 72 0.004 _

Ventilation Samples Sample 6 0.3 3.4 0.088 0.094 (horiz.) 2,230 (h)

Sample 8 0.8 10 0.08 0.09 (hori.) 4,667 (v) 1.1 Sample 14 0.4 7.6 0.053 0.059 (vert.) 4,667 (v)

Cable Trays Subject to Containment Spray (1T See Note 1 N/A N/A N/A 0.094 1,795 0.4 Walls Sample 10 0.5 34.9 0.014 Sample 11 0.1 36 0.003 0.059 13,738 1.8 Sample 15 2.0 45 0.044 TOTAL: 82,245 11.3 (1) Cable tray debris was not sampled due to concerns about employee safety and equipment operation. The debris load for cable trays is assumed to be the same as horizontal ventilation ducts.

The evaluation methodology used for the latent debris quantification is as follows.

Debris samples were grouped by surface type: floors, Containment liner, ventilation ductwork, cable trays subject to Containment Spray impingement and walls.

The Sample Mean and the Sample Standard Deviation were determined for the debris mass found per unit area.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 10 of 77 Where: X- mean 1or group of samples (g/ftM) xi- individual sample mass per area (gift2-n- number of samples in group S- sample standard deviation (g/ft2 Assuming the debris is normally distributed, and the number of samples is small relative to the total population, an upper limit on the mean debris loading was determined from the T-distribution. A 90% confidence was selected.

T - DISTRIBUTION VALUES The upper-tailed t -distribution values provided are (Ret. 6.1.8, pg. 230) [partial table below) at the 90% confidence level 4Q = 1 - 0,9 = 0.1), where the degrees of freedom (v) is the number of samples minus 1.

= 1.886 a for 3 samples t = 3.078 o for 2 samples v , 1 0.25 (75%) 0.10 (90%) 0.05 (95%) 0.025 (97.5%)

1 1.000 3.078 6.314 12.706 2 0.816 1.886 2.290 4.303 3 0.765 1.638 2.353 3.182 4 0.741 1.533 2.132 2.776 5 0.727 1.476 2.015 2,571

6. 0,718 1.440 1.943 2.447 7 0.711 1.415 1.895 2.365 8 0.706 1.397 1.860 2.306 9 0.703 1.383 1.833 2.262 X'UL - x+t+tL Where: tUL- t distribution value at 90% confidence for sample size n AUL- upper limit on the mean debris loading at 90% confidence To estimate the debris mass for a surface type, the upper limit on mean debris loading is multiplied by the total area for that surface type. The total latent debris is the sum of the totals for each surface type.

Recent Programmatic Chanqes While preparing the response to this RAI, industry benchmarking was performed that concluded:

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 11 of 77

" The number of latent debris samples collected by our program is low compared to others

• There are additional surfaces in Containment that should be added to our program, and

• Kewaunee's Containment is smaller than many PWRs Consequently, the following changes were recently made to Kewaunee's program:

1. The initial latent debris evaluation performed for Kewaunee by a vendor was embedded in the debris generation calculation. A new calculation has been issued that supersedes the latent debris portion of the initial vendor calculation. The new calculation will be used in concert with Dominion fleet procedure, CM-AA-CRS-1 01, Latent Debris Collection and Sampling Procedure, Revision 2, which was adopted at Kewaunee in February 2010. The new calculation:

• Provides guidance where to collect latent debris samples.

" Specifies obtaining at least 24 usable samples, with samples from each of the surface types.

" Specifies additional surface area and surface types. Debris loading for the newly identified surfaces in the evaluation was assumed based on sample results from similar surfaces. Additional samples are scheduled to be taken during the next refueling outage in 2011.

" The revised quantity of latent debris in Containment is 21.903 lbs. The revised quantity is bounded by the 100 Ibm latent debris assumed in the GSI-191 analyses, and the 100 Ibm latent particulate and 15 Ibm latent Fine fiber used in the large scale flume testing. Note: As indicated in Attachment 1, the new maximum allowable quantity of latent debris in Containment will be limited to 61 Ibm to ensure a thin bed of fiber cannot form on the recirculation strainer.

The new latent debris calculation, C1l1928, Revision 0, is included as Enclosure C-1.

2. As noted in Item 1 above, the Dominion fleet procedure for latent debris sampling, CM-AA-CRS-101, Revision 2, was adopted at Kewaunee in February 2010.

Kewaunee-specific Nuclear Engineering Procedures (NEP), NEP-04.22 and NEP-04.23, were subsequently deleted. Revision 2 of the Dominion fleet procedure, CM-AA-CRS-1 01, incorporated Kewaunee-specific latent debris sampling and evaluation guidance.

The fleet procedure, when used with Kewaunee's latent debris evaluation calculation, provides guidance similar to that found previously in procedures NEP-04.22 and NEP-04.23, with the following exceptions:

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 12 of 77

" The fleet procedure allows use of masslin cloth or a vacuum with a high efficiency particulate air (HEPA) filter for sample collection. The previous Kewaunee procedure, NEP-04.23, only specified using a vacuum for sample collection.

• The fleet procedure specifies a sampling frequency of every fifth refueling outage if cleaning is performed each refueling outage, or every-other-refueling outage if routine cleaning is not performed. Sampling is also specified to be conducted after any invasive or extended maintenance (steam generator replacement, for example), or on any frequency specified by the site GSI-191 Program Owner. Kewaunee has adopted this sampling frequency specified by the fleet procedure.

Dominion fleet procedure, CM-AA-CRS-101, Latent Debris Collection and Sampling Procedure, Revision 2, is included as Enclosure C-2.

E. Debris Transport NRC Question 9 Insufficient information was provided in the supplemental response to demonstrate that the debris interceptor testing was conducted in a manner that is prototypical of the expected plant condition. If the interceptor tests are not being used to demonstrate adequate strainer performance, please so state, and the additional questions below need not be addressed. If the interceptor tests are being used to demonstrate adequate strainer performance, then please provide the following additional information concerning the debris interceptor testing:

a. the basis for adding debris with the test pump stopped

b. a description of the procedure for preparing fine debris

c. a discussion as to whether fine and small debris were prepared and weighed separately to determine the quantities used for testing

d. discussion concerning the concentration in the debris slurries prepared for testing and the potential for debris to agglomerate during preparation and addition in a nonprototypical manner

e. description of the debris addition sequence for all types and sizes of debris used in the test. If particulate debris was not included, then please justify not including it in the testing, since it could result in increased flow restriction at the interceptors, leading to greater flow over the tops of the interceptors, consequently increasing downstream transport.

f. description of how far in front of the debris interceptor the debris was added to the test flume and a technical basis

g. description of whether a case considering total blockage at the debris interceptors was considered in the test matrix DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 13 of 77

h. the technical basis for scaling the debris quantity used for debris interceptor testing to the total debris interceptor area

i. description of the extent to which floating transport was analyzed by the test program, since the debris was likely mixed with water (thereby removing trapped air) prior to the test initiation

j. discussion of any sources of drainage from Containment Spray, the refueling canal, the pipe rupture, etc., that enter the Containment pool near the strainer, and the technical basis for considering the overhead sprays used in the test as representative of the plant condition that would likely involve more concentrated streams of break and spray drainage

k. comparison of the range of velocity and turbulence conditions used for the debris interceptor testing to the computational fluid dynamics calculation for the plant condition and the technical basis for the flow conditions used for the testing I. discussion of the flume width and water level used for flume testing and whether these parameters are representative of the analogous parameters for Kewaunee

m. description of the physical characteristics of the debris interceptors including at a minimum the height of the interceptors, the size of any openings in the interceptors, and the total surface area of the debris interceptors

n. discussion of the specific individual percentages of the Fines and of small pieces that transported downstream of the debris interceptors

o. the technical basis for using a 40% Fines and 25% small pieces size distribution for Thermobestos and Okotherm debris. Please further describe the form of the remaining 35% of the Thermobestos and Okotherm debris and provide a technical basis for this debris not being considered as transporting to the debris interceptors either in its destroyed form or as eroded Fines.

p. description of how the results of the debris interceptor testing are being applied to the Kewaunee strainer performance analysis and identification of the quantities of each type and size of debris assumed to be trapped on the plant debris interceptors.

q. description of the methodology used to determine the differential pressure across the debris interceptors due to debris blockage to ensure structural adequacy.

r. explanation for why the interceptor tests with less debris added to the flume experienced greater percentages of debris downstream of the interceptor.

Response

The debris interceptor fiber transport test results reported in our February 29, 2008 letter were performed to model the recirculation system with the debris interceptors in the flume.

The debris interceptors are sections of C8x18.75 channel placed between the interior and outer Containment walls to surround the strainer. The debris interceptors act similar to the existing concrete curb that the original recirculation strainer was installed on. The debris interceptors can prevent debris that may be traveling along the Containment floor from reaching the strainer. The interceptors are 8.375 inches tall (8 inch channel height, mounted on 3/8 inch steel plate). The debris interceptor DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 14 of 77 arrangement is shown in Enclosure D. The lengths of the three debris interceptors are as follows:

" The debris interceptor on south end of strainer (near end module) is 9 feet 2.6 inches in length

• The debris interceptor on the west side of the strainer, between the two interior Containment basement walls, is six feet in length

" The debris interceptor on the north end of the strainer (near the exit piping) is 8 feet 3.4 inches in length The purpose of the debris interceptor fiber transport tests was to determine the quantity of fiber that collects on the recirculation sump strainer without artificially placing the debris directly on the strainer as was done during the 2006 tests. Although the results of the fiber transport tests are still valid, subsequently, Kewaunee performed a series of large scale flume tests to measure strainer head loss with the design basis debris load and with an improved chemical debris surrogate. The debris interceptors were modeled in the large flume. The large scale flume tests are the design basis strainer head loss tests, therefore, the questions related to the debris interceptor tests will not be addressed.

NRC Question 10 The supplemental response described erosion testing that was used as a basis for the assumption of 10 percent erosion of fiberglass pipe cover and Temp Mat fibrous debris.

a. Please describe the test facility used and demonstrate the similarity of the flow conditions (velocity and turbulence), chemical conditions, and fibrous material present in the erosion tests to the analogous conditions applicable to the plant condition.

b. Please justify taking credit for any erosion tests conducted at a minimum tumbling velocity if debris settling was credited in the test flume for velocities in excess of this value (e.g., in front of the debris interceptor).

c. Please identify the duration of the erosion tests and describe how the results were extrapolated to the sump mission time.

Response

As noted in Attachment 1 to this letter, Kewaunee will remove the TempMat insulation from the pressurizer surge line restraints and will remove the fiberglass pipe cover from the RCS Loop B Vault. Following these two modifications, there will not be any TempMat or fiberglass pipe cover in the limiting break locations, a RCS hot leg break in either RCS Loop. Therefore, this RAI is no longer applicable.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 15 of 77 NRC Question 11 Please identify whether erosion of Thermobestos debris in the Containment pool was accounted for in the sump performance analysis. Please state the erosion percentage assumed over a 30-day period and discuss the technical basis for the assumed erosion' percentage.

Response

See response to "NRC Revised Questions 5, 6, 7, and 12".

NRC Question 12 See "NRC Revised Questions 5, 6, 7, and 12" above.

NRC Question 13 Please identify the computational fluid dynamics code used to determine the flow pattern in the Containment pool and provide an overview of the simulations run and modeling assumptions. In addition to this general discussion, please also provide the following specific information:

a. description of how the debris interceptors were modeled in the input deck (e.g., as a porous medium, fully blocked, time-dependent modeling, etc.) and how the flow split between the various interceptors was determined.

b. description of the locations where drainage from the break, Containment Sprays, and any other sources of significant water addition, is assumed to enter the Containment pool and how they are modeled in the code.

c. description of the size of the computational domain and boundary conditions in the model.

d. discussion of the main physical models used in the computational fluid dynamics simulation (e.g., turbulence).

e. basis for concluding that the simulations run are bounding with respect to debris transport.

Response

Kewaunee's computational fluid dynamics (CFD) analysis of the recirculation sump pool was performed by Alden Research Laboratories (ARL). ARL utilized the following computer codes in the development of the CFD:

Fluent, Version 6.1.22 Gambit, Version 2.1.6 AutoCAD, Version 2008 Microsoft Excel 2007 DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 16 of 77 FLUENT Version 6.1.22, is a state-of-the-art general-purpose commercial CFD software for modeling flows involved in complicated geometries. Fluent version 6.1.22 was used to perform the Kewaunee Power Station CFD simulations.

GAMBIT Version 2.1.6 was used to generate the computational mesh and define boundary conditions on surfaces required to perform the CFD simulation. The final solid model included all pertinent features from floor elevation to the water surface elevation at the start of the recirculation.

Microsoft Excel 2007 was used for general spreadsheet calculations.

AutoCAD Version 2008 was used to compute the projected areas where-the velocity exceeds the incipient tumbling velocity.

The objective of the CFD analysis was to model the entire Containment basement, determine the sump pool area velocities, and determine the amount of debris, classified by type and size, which could potentially transport to the Containment sump strainer or debris interceptor areas during the recirculation phase of a LOCA.

The Containment sump pool was segregated into six zones for the purpose of debris transport analysis. Debris transport is determined by comparing the sump pool velocity in each zone to the incipient tumbling velocity for each debris type in the zone. If the Containment sump zone has transport velocities higher than the debris' tumbling velocity, the debris is assumed to transport towards the strainer and/or debris interceptor area.

The analytical methodology follows the methodology outlined in NEI 04-07 and in NRC Safety Evaluation Report (SER) for NEI 04-07. A steady state CFD simulation was performed for the worst-case debris generating break scenario (RCS Loop B hot leg break) to a converged solution. The CFD results were post-processed by plotting three-dimensional (3D) surfaces of constant velocity. The extent of the 3D surfaces were projected onto a horizontal plane to form a flat contour. Closed curves around the projected velocity contour were automatically digitized and the area within the curves was calculated. The area calculated was compared to the total floor area of the zone containing the particular debris type/size under consideration. This comparison was made to determine the fraction of the floor area susceptible to transport. The results of each calculation were tabulated to determine the total fraction of debris transported toward the strainer area for each debris type.

The model was created as follows:

" The model was prepared using plant drawings, photographs and dimensions provided by Dominion staff from field walkdowns.

• Objects above the defined water surface elevation of 595.375 ft (Containment vessel floor elevation 592 ft + water depth 40.5 inches = 595.375 ft) were not included in the model.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 17 of 77

" Relatively small individual objects less than six (6) inches in longest dimension were not included in the model.

" Walls, concrete columns and steel support columns are addressed in the model since they are considered to play an important role in restricting flow. Typically the walls and concrete columns have regular shape and are modeled as shown in the plant drawings. For some steel support columns, the detailed structure, such as the anchor bolts, are not modeled or their shape is simplified.

" The strainer has 14 modules which each has 6 disks. Instead of modeling each disk, each strainer module is simplified as a cubic box with dimensions of 2.25 ft wide, 0.71446 ft long, and 2.89583 ft high and its six faces (top, bottom, north, south, east, west) are open to flow. The cross shape structures on the sides of the strainer modules are not modeled.

" The modules are connected by a pipe with a diameter of 18" which is modeled.

• The three debris interceptors at the entrance of the three openings to the strainer area are modeled as solid shapes. The 3/8 inch gap between the interceptor bottom and the floor is ignored and is blocked to flow.

• The refueling cavity filter skid near the strainer assembly is simplified by modeling four cylinders 32" high and 10" in diameter, and 14 cylinders 32" high and 5" in diameter. All the cylinders are sitting on a 47 high flat slab.

" The reactor coolant drain tank is surrounded by solid walls. The tank is not included in the model, but the walls are included.

" The regenerative heat exchanger is not included in the model. It is assumed not to influence the general flow pattern in the Containment sump because it is a relatively long distance from the strainer area and it is located within a rectangular shape cubicle with three wall sides.

• The service water valve gallery (cluster), in Zone 6 and out of the main recirculation flow path, was modeled as a solid cube for simplification.

An overview of the CFD simulations follows:

Using the solid model, a body-fitted hybrid (hexahedral and tetrahedral cell topology) three dimensional mesh was constructed in GAMBIT, including objects submerged underneath the selected water surface level in the Containment. This geometry was meshed in GAMBIT. The Containment was divided into six proximity zones for debris transportation analysis. The mesh was structured according to the division of the zones. Each zone included a few volumes. The meshed volumes in each zone were grouped as one fluid group. Although hybrid mesh topology was used accordingly, hexahedral topology was applied as much as possible. The entire computational domain was meshed and consists of about 2.7 million cells. Finer mesh was distributed in Zones 1 through 5, which are closer to the strainer modules. Inflow and outflow boundaries for the numerical model were specified in GAMBIT. ARL developed a method for introducing the break flow into the pool, at the water surface, which preserved the momentum and vertical trajectory of the break flow but did not require extending the numerical simulation to the elevation of the break. Spray flow into the pool at the water surface was included in this study. The computational mesh and inflow/outflow boundary specifications were exported from GAMBIT and imported into DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 18 of 77 the FLUENT CFD software program. The values for each boundary condition were set in FLUENT as were the properties of the working fluid (water). Two-equation standard turbulence k-s model with wall functions was used to compute the turbulence kinetic energy, k, and its dissipation rate, F. The computed k and c were used to calculate the turbulence viscosity which was used to close the governing equations. Steady-state converged solution was obtained.

A variety of hydrodynamic parameters were available from the steady-state converged results. Among these parameters and which were used in this study for analysis included velocity components in x, y, and z directions. It should be pointed out that beside the velocities, the pressure, kinetic energy and its dissipation rate were used to monitor and control the convergence of solution.

Two flow simulations were modeled:

" The condition at the initiation of recirculation. Flow to the RCS and out the RCS break is equal to 4456 gpm which is the maximum RWST injection (2586 gpm, SI and RHR) plus recirculation flow through the strainer (1870 gpm). An additional 1390 gpm Containment Spray injection flow enters the sump pool. This condition is modeled at the minimum sump level at the initial onset of recirculation and lasts approximately 14 minutes.

• The long term recirculation condition. This is modeled as 1870 gpm flow through the recirculation strainer that enters the RCS and spills from the RCS back to the sump.

For conservatism and simplification, this scenario is modeled at the same minimum sump water level, however, the actual sump water level at this condition would be significantly higher.

Both flow simulations were prepared for the limiting break, a RCS Loop B hot leg break.

A break in RCS Loop B not only creates the worst quantity and combination of debris, but RCS Loop B is also physically closer to the recirculation sump strainer. Closer proximity to the strainer results in a more conservative evaluation of turbulence caused by the RCS spill flow as well as debris distance traveled.

See also the Alden presentations from the September 15, 2009, and November 10, 2009, teleconferences, included as Enclosures E-1 and E-2.

See also response to Questions E.15, velocity and turbulence contour plots, and E. 16, debris distance traveled.

NRC Question 14 Drainage from the elevation above the Containment basement was assumed to reach the Containment pool primarily through the south stairwell due to a 2-inch floor collar, weirs, and a toe-rail at the north stairwell. Following a loss of coolant accident, if large pieces of debris are able to settle out on this floor elevation, flow to the south stairwell DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 19 of 77 could be partially restricted, resulting in pooling of water and redirection of part of the drainage through the north stairwell that is closer to the Containment sump strainer.

Please describe how these phenomena were analyzed in the debris transport calculation, how flow to the Containment pool was distributed between the north and south stairwells, and whether any hold up of water on this elevation was considered.

Response

Note: As indicated in Attachment 1 to this letter, Kewaunee will remove the TempMat insulation from the pressurizersurge pipe whip restraintsand will remove the fiberglass pipe cover from the Service Water piping in RCS Loop B Vault. These two activities will eliminate any fibrous debris that would be largerthan Fines. Reflective metal insulation, although not transportablein the Kewaunee sump pool, is still a generated debris larger than Fines, therefore, this RAI will be responded to.

The steam generators, reactor coolant pumps and pressurizer are located inside concrete compartments (referred to as "vaults"). The RCS piping, except immediately adjacent to the reactor nozzles, is located inside the vaults (refer to Enclosure A).

Inside the vaults are horizontal steel grate work platforms and solid concrete floor surfaces, and vertical wall partitions. The concrete vault structures are open to the Containment on top, above the highest floor elevation (see Enclosure M, page 2), and are open to the Containment at the bottom of the Vaults, approximately 13 ft above the Containment basement floor elevation. Debris generated by a LOCA inside the vaults could wash down to the sump (basement elevation) from the openings in the vaults, or could be ejected into the upper Containment elevation. Debris ejection into the upper Containment elevation would be minimal or limited to small debris due to the concrete and steel structures and components inside the vaults (see response to RAI Question 40).

Potential LOCA pipe break locations outside the Vaults include a break at the reactor vessel nozzle, or piping connected to the RCS with a much smaller diameter than the RCS. A reactor vessel nozzle break is not a limiting debris generation location (see Response to Question 1). There are no breaks outside the Vaults that would generate large debris on the Containment floor elevations above the basement floor as to cause a potential for debris blockage of the drainage path down the unobstructed south stairwell.

Containment Spray drainage enters the Containment basement via the following main paths: 1) spray into upper vaults that drains to the basement out the bottom of the vaults, 2) spray into the refueling cavity that drains to the Containment basement via the cavity drain, 3) spray onto solid floor surfaces that drains to lower floor elevations and eventually to the basement via unobstructed floor penetrations (on two upper floor elevations only; the floor elevation above the Containment basement has collars around floor penetrations ), 4) down unobstructed stairwells, or 5) through floor drains that lead to an isolated waste sump that overflows into the basement/sump elevation. There is DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 20 of 77 no Containment Spray after the RWST injection phase ends for the design basis event (recirculation spray is not used in response to a design basis event).

The calculation of minimum sump water level at the initiation of recirculation assumes water holdup on all floor elevations due to Containment Spray drainage that has not yet reached the sump (see response to Question 34).

Views of the Containment Vault configurations are included as Enclosures A, E-3 (new) and M.

NRC Question 15 Please provide contour plots of the velocity and turbulence in the Containment pool.

Please also provide close-up plots of the velocity and turbulence contours in the region of the strainer and its immediate surroundings. In addition, please provide a table of the head loss test flume (average) velocity as a function of distance from the test strainer and the basis for the velocities chosen. Please identify the turbulence level simulated in the test flume and state the flume width(s) used for testing.

Response

Note: As indicated in Attachment I to this letter, following removal of the fibrous insulation materialon the pressurizersurge line pipe whip restraintsand the Service Water piping in RCS Loop B Vaults, all remainingfibrous materialin Containment will be considered Fines and subject to transportto the strainerand is not of sufficient quantity to create a thin bed of fiber on the strainer.

See Enclosure E-2 for the ARL presentation used during the November 10, 2009 telecon between Dominion staff, their vendors and the Nuclear Regulatory Commission.

The pictorials on the following page display the layout of the Containment sump. For the limiting break, RCS Loop B hot leg break at the Steam Generator (SG), the break location is located one elevation above Zone 1. RCS break flow exits the SG/Reactor Coolant Pump (RCP) vault and washes into the sump from three vault openings.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 21 of 77 C8x18.75 channel (typ.)

VDebris Concrete support wall (typ.)

Interceptor SStrainer I Debris Interceptor Break Flow to Sump 0 Over north and south ledges T 0 Through 2x3 ft hatch Flow exiting the vault above Zone 1 washes primarily into Zones 2, 4 and 6 during the sump pool fill phase.

Velocity contour plots for the Containment sump were prepared. Contour plots for the debris transport determination, the start of recirculation with combined reactor vessel DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 22 of 77 injection and Containment Spray from the RWST and Containment sump recirculation in progress, are shown below. Break flow momentum over the north and south ledges results in higher sump pool turbulence and velocities to maximize debris transport. The plots display the velocity and turbulent kinetic energy distribution at the middle of the water column.

1.00e+00 9.50e-01 9.00e-01 8.50e-01 8.00e-01 7.50e-01 7.00e-01 6.50e-01 6.00e-01 5.50e-01 5.00e-01 4.50e-01 4.00e-01 3.50e-01 3.00e-01 2.50e-01 2.00e-01 1.50e-O1 1.00e-01 5.00e-02

"_X 0.00e+00 Velocity magnitude (ft/s)

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 23 of 77 1.OOe-0 1 I

9.50--02

9. DD*-02 8.509-02 8.DOe-02 7.509-02

7. D09-02 6.50o-02 6.00e-02 5.50e-02 5.DOOe-02 4.508-02 4.00O-02 3.50e-02 3.006eM0 2.50e-02 2.DOL-02 1.50e-02 1.O0e-02 5.OOe-03

ý-_x

0. OOei-OC Turbulence (ft 2 /sec 2 )

Contour plots for the long term recirculation condition are displayed below (injection phase complete). The contour plots are conservative as a low sump pool water level (40.5 inches depth) was used for simplicity when preparing the CFD. The minimum sump water level at the onset of recirculation is calculated as 43.44 inches and the sump water level during long term recirculation is > 5.75 ft. The test flume was constructed to represent the conditions for long term recirculation, using the conservative low sump pool water level.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 24 of 77 5.00.-01 I

4.750-01 4.500-01 4.250-01 4.000-01 3.75"-01 3.50e-01 3.25.-01 3.00.-01 2.75",1 2.50"1l 2.250-01 2.00e-01 1.750-01 1.500-01 1.250-01 1.00C-01 7.500-02 5.00e-02 2.500-02 0.000+00 Velocity magnitude (ft/s) 1.000-02 I

9.500-03 9.000-03 8.500-03 8.000-03 7T500-03 7.00e-03 6.500-03 6.000-03 5.500-5.000-03 4.50"-3 4.000-03 3.500-03 3.000-03 2.500-03 2.000-03 1.500-03 1.006-03 5.00-04 0.6+00'X Turbulence (ft 2 /sec 2 )

Overall, the sump pool is relatively calm in the area of the strainer, as shown below.

Velocity and turbulence levels are low, especially in the main transport paths to the strainer, approaching from the north (right side of page) and south (left side of page).

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 25 of 77 2.008-01 I

1.90e-01 1.800-01 1.70e-01 1.60e-01 1.506-01 1.40e-01 1.306-01 1.20e-01 1.l1Oe-01I 1.000-01 9.00e-02 8.00e-02 7.00e-02 6.00e-02 5M00-02 4.00e-02 3.00e-02 2.00e-02 el m n0e-0.000e+00 Velocity magnitude (ft/s) 1+00e-02 I

9.500-03 9.00e-03 8.50e-03 8.00e-03 7.50e-03 7.00e-03 6.50e-03 6.00e-03 5.509-03 5.00e-03 4.50e-03 4.00e-03 3.50e-03 3.00e-03 2.50e-03 2.00e-03 1.50e-03 1.000-03 5.00e-04 0.00e+00 Turbulence (ft 2/sec 2 )

The center debris interceptor between the interior support walls (C8xl 8.75 channel, shown in the first pictorial above) limits flow to the strainer at this location by creating a toroidal flow pattern. Flow exiting the upper elevation falling out of the 2x3 ft hatch above Zone 1 (see first pictorial above), penetrates the water column and spreads along DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 26 of 77 the floor of Containment. The jet sets up a vortical flow field. When the jet hits the debris interceptor, the water is forced vertically upward and sets up a complex three dimensional flow field that allows only a portion of the flow to penetrate to the strainer side of the debris interceptor. This results in higher approach velocities at the north and south ends of the strainer.

lJ00l+00 I

• 5.061 9.006-01 7.50-l01 7.00.-C1 6.560101 6.00.-01 450.-01 4.60"1C 4.00,01 3.50641 3.00s-01 2 .00@-Cl 1.000-CI 5.000-02 0.00.*0O Hatch Flow Spreads Along the Floor i oroldal i-low Pattern The velocity field calculated for long term recirculation was used as the basis to develop the approach velocity to the strainer in the test flume. Three main approaches exist to the strainer, from the left (south), right (north) and center (west) as viewed in the figures.

The west approach is limited by the debris interceptor and the toroidal flow field at that location that results in flow both toward and away the strainer with little net flow. The average velocities calculated over each of the approaches to the strainer were then DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 27 of 77 averaged again, weighting the highest velocity double to more conservatively represent the overall approachto the strainer. The approach planes were trimmed to neglect any stagnant areas of flow in the general approach area. The following table shows the approach velocities calculated in this manner as a function of distance away from the strainer. The table also includes the flume width calculated based on the modeled module flow rate and water depth (40.5 in.). Finally, the table also includes the local Reynolds Number obtained at each location in the flume. Although the Reynolds Numbers are low, they are firmly above that required for turbulent free surface flow (2000). The figure that follows compares the turbulence calculated over the same approaches in the Containment and in the test flume. The turbulence plotted for the flume represents the effective turbulence level, accounting for the significant difference in viscosity between the test temperature and the Containment recirculation temperature (1100 F vs. 2000 F).

DISTANCE FROM VELOCITY FLUME WIDTH HYDRAULIC REYNOLDS STRAINER (FT/SEC) (IN.) RADIUS (FT) NUMBER (FT) 1 0.10 10.4 0.39 6704 2 0.10 9.9 0.37 6045 3 0.10 11.3 0.41 6644 6 0.08 14.3 0.51 6435 10 0.09 11.7 0.42 6617 21 0.12 8.9 0.33 6821 25 0.13 8.5 0.32 6852 30 0.13 8.4 0.32 6861 0.0025 0.002 0.0015 i=.

0.001 0.0005 00 0 5 10 15 20 25 30 35 Distance Back From Strainer (ft)

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 28 of 77 Following removal of fibrous insulation material on the pressurizer surge line pipe whip restraints and the service water piping in RCS Loop B Vaults, all remaining fibrous material in containment will be considered Fines and will be subject to transport to the strainer. It is not of sufficient quantity to create a thin bed of fiber on the strainer.

NRC Question 16 Please identify the distance from the strainer at which debris was added to the test flume. Please justify the conservatism or prototypicality of this distance based on the transport analysis results for blowdown, washdown, and pool-fill transport.

Response

The large scale flume tests conducted at ARL in August 2008 measured strainer debris bed head loss. Other than latent fiber addition which is addressed in F.19.c.ii, debris was introduced into the flume via the drop zone, 29 ft upstream of the strainer.

ARL performed an analysis to determine the distance debris traveled in the sump pool to the strainer area. Refer to Enclosure E-2. Note: Enclosure E-2 indicates transportof material to the inactive sump (Sump C) is not credited. As stated in Attachment I to this letter, the revised debris inventory will credit 15% of fibrous Fines, Thermobestos particulateand qualified coatings as transportingto the inactive sump.

The following is a description of the sump pool fill transport:

" As shown in Enclosure E-2, for purpose of conducting the CFD, the Containment sump was divided into six zones.

" Zone 1 is located one elevation below the RCS Loop B RCP and SG vaults where the limiting debris generation break occurs. The flow path out of the vault area into the basement/sump is over the north and south ledges of the elevated vault, and through a 2 ft x 3 ft hatch opening in the vault floor slab.

" Flow exiting the vault above Zone 1 washes primarily into Zones 2, 4 and 6 due to the large sump volume in these zones.

• Zone 6, which is located the farthest away from the recirculation strainer, contains > 60% of the sump volume. Therefore, a significant quantity of debris will wash into this area during sump pool fill. This transport of debris away from the strainer during pool fill was not credited in the CFD debris transport analysis.

ARL determined the distance traveled by the debris using the CFD and peak transport conditions (start of recirculation with RWST injection in progress). The six Containment zones were subdivided where appropriate according to the fraction of flow in each zone.

The centroid of each zone or subzone is determined and the distance from each DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 29 of 77 centroid to the strainer is calculated. Using a relatively low tumbling velocity for debris, 0.06 ft/sec for example, the distance measured from the centroid of each zone/subzone to the strainer was calculated as follows (refer to Enclosure E-2 for pictorial view):.

ZONE DISTANCE (FT) COMMENT Z11 41.14 Z13 39.43 Z2 39.56 Z3 24.18 Z4 30.74 Z5 6.10 Zone 5 is the strainer area Z61 61.73 Z63 88.06 Using this same methodology, the zones were divided based on the fraction of flow for, the selected sump pool velocity, the centroid was determined for each zone and the distance from the centroid to the strainer for each zone was measured. The quantity and type of debris in each zone was considered and the resultant debris travel distances are determined:

DEBRIS SUMP POOL VELOCITY DISTANCE TO (FT/SEC) STRAINER (FT) 100% Transportable N/A 51 Debris Debris w/Tumbling 0.06 50 Velocity > 0.06 ft/sec Debris w/Tumbling 0.25 45 Velocity > 0.25 ft/sec Debris w/Tumbling 0.66 38 Velocity > 0.66 ft/sec Using the analysis above, placing the debris in the test flume 29 ft upstream of the strainer is determined to be conservative for the purposes of testing.

NRC Question 17 Please describe how the potential for debris transport. in the vicinity of the strainer via.

floatation was considered in the head loss tests for Kewaunee.

Response

The large scale flume tests conducted at ARL in August 2008 measured strainer debris bed head loss. These tests were conducted in a large flume with heated (approximately 1200 F) water. The large scale flume included a heat recirculation loop with a heat recirculation pump and 800,000 BTU/hr heat exchanger. Use of heated water eliminated trapped air bubbles in the debris and resulted in minimal floating debris.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 30 of 77 Prior to entry into the flume, non-chemical debris was placed in hot water (~120' F) and mixed to help eliminate trapped air in the debris.

Additional Verbal NRC Request Address the potential for debris transport via floatation in the Containment.

Response

As indicated in Attachment 1 to this letter, following removal of the fibrous insulation on the pressurizer surge line pipe whip restraints and the Service Water piping in RCS Loop B, the remaining fibrous material in Containment will be considered as Fines and subject to transport to the recirculation strainer. The total quantity of fibrous material will be limited to prevent creating a thin bed of fiber on the recirculation strainer that can filter particulates and result in a high strainer head loss. Because all debris generated ig.

assumed to transport to the strainer, this question is no longer applicable.

F. Head Loss and Vortexing NRC Question 18 Please provide the clean strainer head loss (CSHL) methodology for the non-strainer portions of the assembly. Please provide the assumptions used for the CSHL calculation.

Response

PCI calculated Kewaunee's clean strainer head loss. The CSHL value includes losses from the strainer assembly, as well as the exit piping that discharges the strained water into the recirculation sump pit where the RHR pumps take suction. The following presents first the CSHL calculation for the strainer assembly, and then the non-strainer components, i.e., the attached discharge piping and sump entry.

Strainer Assembly CSHL The following equation was used to calculate the strainer exit velocities: 4r Vex = Qstr / Aex Where, Qstr = strainer water flow rate, gpm x 0.002228 to convert to ft3/sec 2

Aex = exit area, or cross section area of the inside of the strainer's core, ft Vex = Strainer Exit Velocity, ft/sec DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 31 of 77 The equation for the strainer only CSHL, i.e., without any pipe and/or fitting losses, is:

HLstrainer- A + K1 v Vex + K2 (Vex2 / 2g)

Where, v = water's kinematic viscosity, ft2/sec (a function of water temperature) 2 g = gravitational constant, which is 32.2 ft / sec A = a constant with a very small value of 0.002205 feet of water - 0, and is therefore ignored K1 = a coefficient multiplied by v to allow adjustment to the water temperature K2 = another coefficient that is multiplied times the dynamic head of the water at the strainer's exit.

Coefficients, K1 and K2 have the following values (determined by a regression analysis of the PCI test data):

K1 = 1,024 and K2 = 0.8792 With the values of the coefficients determined and utilizing the CSHL equation, the Base Head Loss, HLBase was calculated for different water temperatures where the value of kinematic viscosity, v is selected based on the design basis water temperature.

Kewaunee specified a conservative long term sump water temperature of 65°F. The actual base CSHL is computed using the value of Exit Velocity, Vex for the particular water flow rate. Selecting a value of v. for the water temperature, the Exit Velocity is computed using Vex = Qstr / Aex and the values of specified water flow rate values, respectively, for the Kewaunee strainer. Each strainer's core tube has an 18.00 inch outside diameter and a 0.06 inch wall thickness. Therefore, the value of internal cross sectional area of the core tube is computed by the following equations:

Aex = 71 Dex 2 /4 Where, Dex = inner core tube diameter Dex = outer diameter - 2 x core tube wall thickness

= 17.88 inches 2

Therefore, Aex = 1.744 ft Using the computed value for Aex the Exit Velocity, Vex, for the strainer assembly is computed using the specified flow rate of 1920 gpm (see response to Questions 33 and 19.c for flow rate discussion).

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 32 of 77 Vex = Qstr / Aex 3 2

= 1920 gpm x 0.002228 ft /s/gpm / 1.744 ft

= 2.453 ft/s The resultant value for Vex was then used to calculate the CSHL from the previously discussed equations as follows:

HLstrainer= K1 V Vex + K2 (Vex2 / 2g)

= (1024) (1.138 x 10-5) (2.453) + (0.8792) (2.4532/ 64.4)

= 0.02859 + 0.08215

= 0.111 The following table provides a summary of the values obtained from the above equations and the resultant Clean Strainer Head Loss for the strainer assembly without the discharge piping.

Summary of Calculated Strainer Only Clean Strainer Head Loss Parameter Value Total Suction Flow, gpm 1,920 Water Temperature, OF 65 Water Kinematic Viscosity, ft2/sec 1.138 x 10.'

Internal Core Tube Outer Diameter, inches 18.00 Internal Core Tube Thickness, inches 0.06 Internal Core Tube Inner Diameter, inches 17.88 Internal Core Tube Cross-Sectional Area, ft2 1.744 Design Strainer Exit Velocity, ft/sec 2.453 Calculated Uncorrected CSHL, feet of water 0.111 DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 33 of 77 Strainer Discharge Piping and Sump Entrance The 18.00 inch (outside diameter, OD) strainer core tube discharge is attached to the 18.00 inch OD strainer assembly discharge piping. The strainer discharge flow enters a short straight run of pipe where it passes through a horizontal 120 mitered elbow, then enters a straight run of pipe. The flow then enters a horizontal 34.30 mitered elbow, a short straight run of pipe, and a horizontal 55.00 mitered elbow that aligns the strainer discharge pipe to the sump cover. At the sump cover, the strainer discharge flow passes through a 900 short radius elbow that discharges into the sump pit reservoir.

Head loss was calculated for each subcomponent, then summed and added to the strainer assembly head loss to obtain the total clean strainer head loss. The subcomponent calculations are provided below.

Straight Pipe The piping between the strainer assembly and the sump pit cover plate is 18 inch OD schedule 10S stainless steel with a 0.25 inch wall thickness. The pipe's inside diameter is slightly less than that of the core tube (i.e., 17.50 inch vs. 17.88 inch). For the pipe, the ID = OD - 2 x wall thickness = 18.00 - 2 (0.25) = 17.50 inches or 1.458 feet, which we will call DID. The cross-sectional area, Apipe, of the pipe is then calculated.

Apipe = TT DID 2 /4 2

= 1.670 ft With the pipe cross-sectional area determined, the flow velocity, Vpipe is calculated.

Vpipe = Qstr / Apipe

= 1920 x 0.002228 / 1.670 Vpipe = 2.562 ft/s The straight pipe runs cumulatively total approximately 156 inches, or 13 feet. Using this length as a bounding value, along with the flow velocity, Vpipe, an estimate of the head loss resulting from this straight pipe is determined. The Darcy-Weisbach equation is used for head loss associated with incompressible flow in pipe to calculate the head loss per unit length of pipe.

Ahf = f/D(Vpipe) 2 /2gAL Where, A hf = head loss for a straight pipe, ft. water, AL = total pipe length = 13 ft.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 34 of 77 Vpipe = local water velocity in the pipe, ft/sec = 2.562 ft/s f = friction factor, dimensionless D = internal diameter of the pipe = 17.50 in = 1.458 ft g = gravitational constant = 32.2 ft/sec 2 .

The friction factor, f depends on the Reynolds Number (Re), which is dimensionless, and the pipe diameter (D). Any temperature effect is incorporated in v, the water's kinematic viscosity, which is temperature dependent. Re is then calculated by using the following equation:

Re =V D/v Where the value of v = 1.138 ft2 X 10-5 / s for the evaluated 650 F water. Re is calculated to be 3.282 x 10 5 . Utilizing the Moody Diagram results in a conservatively determined friction factor value, f of 0.013.

The value of f is then used to calculate head loss for water flow through the total 13 foot length of straight pipe.

HLstr pipe= (0.013/1.458) (2.5622) / (2 x 32.2) x 13

= 0.0118 feet of water Increasing this value by 10% for conservatism results in a total straight pipe head loss, HLstr pipe, of 0.0130 feet of water.

Mitered Elbow The mitered elbows consist of three (3) different miters: 120, 34.30, and 550. Each of these requires consideration for head loss, as detailed in the following sections.

For a mitered elbow, the head loss can be calculated utilizing the following generalized equations:

HLfitting = Kfitting V2 / 2g and Kfitting = axf 120 Mitered Elbow DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 35 of 77 The 120 miter elbow is bound by a 150 mitered elbow for which the value of a = 4. With the friction factor, f = 0.013, the value of K 12 miter can be determined as follows.

K 12 miter aa 12 x f = 4 x 0.013 = 0.052 34.30 Mitered Elbow The 34.30 mitered elbow is bound by the a value for a 450 mitered bend, a = 15.

K 34 .3 miter = a 34 .3 X f= 15 x 0.013 = 0.195 550 Mitered Elbow The 550 mitered elbow is bound by the a value for a 600 mitered elbow, a = 25.

K55 miter = a60 X f = 25 x 0.013 = 0.325 The sum of the coefficients associated with the three (3) mitered elbows is 0.572 feet.

900Short Radius Elbow The head loss for the 900 short radius elbow is determined, where a = 20 and f = 0.013 for a smooth inside surface on a 18 inch pipe elbow.

K 90 el = a90 elbow X f = 20 x 0.013 = 0.260 Mitered and 900 Short Radius Elbow Head Loss With the individual K value established for the subject mitered and 900 short radius elbows, the head loss is then calculated for the subject fittings.

Kfittings = K 12 miter + K 34 .3 miter + K 55 miter + K 90 el

= 0.052 + 0.195 + 0.325 + 0.260 = 0.832 Utilizing a generalized equation and the velocity value, Vpipe = 2.562 ft/s, the head loss contribution from the four fittings, HLfittings can be determined.

H Lfittings = Kfittings X Vpipe 2 / 2g

= 0.832 x 2.562 2 / 64.4

= 0.0848 feet of water.

Increasing this value by 10% for conservatism results in a head loss associated with the fittings of 0.0933 feet of water.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 36 of 77 Water Enterinq Sump Pit Head Loss The head loss associated with the strainer discharge flow entering vertically downward into the sump pit is addressed. There is a final head loss resulting from the expansion of that flow into a "reservoir" (i.e., sump pit). For this configuration, Kexit = 1.00 and Vpipe

= 2.562 ft/s.

HLexit = Kexit x Vpipe 2 / 2g

= 0.102 feet of water.

Increasing this value by 10% for conservatism results in a HLexit of 0.112 feet of water.

The table below summarizes the bounding values of head loss discussed above. All.

head losses are in feet of water.

Calculated Clean Strainer Subcomponent Head Loss Parameter Value Uncorrected CSHL 0.111 6% Uncertainty Correction of the CSHL 0.007 Strainer Length HL Corrections 0.020 Strainer Module to Module Transition (+10% 0.0085 conservatism)

Attached Piping Head Loss (+10% conservatism) 0.0130 Fitting Head Loss (+10% conservatism) 0.0933 (Elbows)

Entering Sump Water Head Loss (+10% 0.112 conservatism)

Total Corrected CSHL with Attached Piping 0.365 NRC Question 19 Very little head loss and vortexing information was included in either submittal. Please provide information on the testing conducted on the strainer including the following, along with other relevant information:

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 37 of 77 19.a Identify the maximum debris head loss measured during testing. Identify the test clean strainer head loss portion of the total separately. Provide the temperature at which the head loss was measured.

Response

As reported in our December 18, 2008 response, the following data was provided:

The August 2008 large scale flume tests were conducted with one full size strainer module, as compared to a smaller-scale strainer module used in February 2006.

For conservatism, the original calculated 40.5 inch recirculation sump level was maintained. The strainer head loss test results validated the Kewaunee recirculation strainer design and is summarized in the table below.

TEMP- TEMP- TOTAL TEMP-'.° CORRECTED DEBRIS BED CORRECTED CORRECTED TEST CLEAN HEAD HEAD LOSS DEBRIS BED LOSSES (Note 1) LOSS (FT OF WATER) HEAD LOSS (FT OF (FT OF WATER) (FT OF WATER) WATER)

Maximum design basis debris load, 0.365 0.51 0.83 1.10 with margin (Note 2)

Maximum design basis debris load, with additional 0.365 1.67 3.01 3.28 debris load margin (Note 3)

Note 1: Test results are temperature-corrected, where noted, to 65 deg. F.

Note 2: The first head loss test in August 2008 included the following debris load margin:

a. TempMat test quantity included 10% margin above the transported quantity

b. Fibrous cable insulation included 10% margin

c. Thermobestos/calcium silicate insulation included 10% margin

d. Latent debris included 785% margin

e. Inorganic zincs included 107% margin

f. Phenolic Epoxies included 7% margin

g. Enamel and factory coatings included 8% margin.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 38 of 77 Note 3: A supplemental head loss test was conducted. The debris load margin was increased as follows (see table above):

a. TempMat test quantity included 20% margin above the transported quantity.

b. Chemical debris was doubled, providing 100% margin.

c. Fiberglass pipe cover included 83% margin.

d. Latent debris included 918% margin.

The maximum measured head loss across the debris-laden recirculation strainer, 3.28 ft of water, which includes debris load margin and clean strainer losses, is significantly less than the maximum allowable strainer head loss of 10 ft of water.

19.b Provide information that clearly shows how the debris head loss was extrapolated to temperatures other than the test temperature. If plant CSHL was adjusted for temperature, please provide the CSHL at the various temperatures that were considered. Provide the plant CSHL and debris head loss separately for each temperature.

Response

CSHL and debris bed head loss was determined for the given test temperature, then corrected to a conservative long term sump water temperature of 65 deg F.

Head loss values at intermediate temperatures were not calculated. The maximum allowable strainer head loss (debris bed and clean strainer losses combined) is 10 ft of water.

The following data summarize the CSHL and debris bed losses at the temperature-corrected values.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 39 of 77 COL. A COL. B COL. C COL. D COL. E COL. F CSHL STRNR AND CSHL DEBI DEBRIS BED TOTAL TEST DISCHARGE STRAINER TEST CSHL BED HEAD HEAD LOSS LOSSES (Note 1) PIPING ONLY (FT OF (FT OF WATER) LOSSFT (FT OF (FOF FTFOF (FT OF WATER) WATER) WATER) WATER)

WATER)

Maximum design basis debris load, 0.365 0.111 0.01807 0.51 0.83 1.10 with margin (Test 3)

Maximum design basis debris load, with 0.365 0.111 0.01807 1.67 3.01 3.28 additional debris load margin (Test 9)

Notes:

1) Columns A, B, C, E and F values are temperature-corrected to 65 deg. F

2) Column A - calculated CSHL, strainer modules plus discharge piping losses

3) Column B - calculated CSHL, strainer modules only

4) Column C - measured CSHL by test, strainer modules only

5) Column D - measured debris bed losses by test

6) Column E - debris bed losses temperature-corrected to 65 deg. F

7) Column F - total head loss; strainer, discharge piping and debris bed losses [Col. A -

Col. B + Col. C + Col. E = Col. F]

The CSHL (Col. A) temperature-correction was calculated using the kinematic viscosity of the water at 65 deg. F. The debris bed head loss temperature correction (Col. E) was calculated using the dynamic viscosity of the water at the test temperature(s) and the long term temperature (65 deg F.). Excerpts from the Clean Head Loss and Total Head Loss calculations are included as Enclosures F-1 and F-2. The test. plots are provided in response to Question 23.

19.c Provide the head loss test methodology including details of the following, for each test:

i. debris introduction sequences ii. if any debris additions, including latent debris surrogate, were made at less than the scaled 100% flow rate, provide the flow rate at which the debris was added iii. debris preparation methodology and resulting surrogate size distributions iv. debris characteristics for all debris surrogates used during testing

v. general procedure/steps for conducting the tests vi. description of the test facility DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 40 of 77 vii. description of debris introduction techniques including the debris mixtures and concentration (with respect to water) for each debris addition viii. thin bed incremental amounts of fibrous debris added (theoretical thickness and the basis) and the type(s) of fiber added ix. the amounts (volume or mass) of each size (fine, small, etc.) of all debris that was added to the test flume for each debris addition, and the location of the debris addition with respect to other equipment within the test flume

x. scaling factors xi. flow rates xii. verification that particulate debris surrogate amounts were density-corrected so that the required volume of surrogate was used during testing xiii. statement as to whether stirring was used, and if used, whether the stirring affected the debris bed (either by forcing larger debris onto the bed or washing debris from the bed) xiv. the amounts of debris that settled in the test apparatus xv. information that justifies that excessive agglomeration of debris did not occur due to higher than prototypical debris concentrations within the flume or higher than expected concentration during debris addition

RESPONSE

Test Overview The 2008 large scale flume tests were performed for Kewaunee by PCI and AREVA at Alden Research Laboratories (ARL). The flume layout was configured for Kewaunee's test to include varying widths from 8.375 to 14.25 inches. Water depth was 40.5 inches.

Flume length was 45 feet. A CFD analysis was performed by ARL to determine the test flume wall design. A debris interceptor was placed across the width of the flume, upstream of the strainer. The debris interceptor was a replica of the plant design, a steel C8x1 8.75 channel. The debris interceptor was mounted on 3/8 inch steel plate to model installation in the Containment.

Debris introduced into the flume included all debris types, fibrous, particulate and chemical debris. Head loss tests were performed at the design basis flow rate of 1920 gpm (1870 gpm flow through the strainer, plus 50 gpm additional for conservatism).

Scaling Factor (F.19.c.x)

A full size strainer module from Kewaunee's inventory was used for the tests. The strainer module has a surface area of 54.8 ft2. The surface area of the strainer installed in the plant is 768.7 ft2. The flume test conditions (flow rate and debris quantities) were scaled down to 7.129% for the test strainer size.

54.8 ft2 / 768.7 ft2 plant strainer = 7.129% scale Description of Test Facility (F.19.c.vi)

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 41 of 77 Flume design layout and photographs are included in Enclosure G.

The ARL test apparatus consisted of a steel flume measuring 10 ft wide, 5 ft deep and 45 ft long. Inside the steel flume, plywood was used to contour the flume wall to simulate the Containment approach velocities. The upstream end of the flume was used to introduce the flow into the flume, resulting in a 30.59 ft long test section. The flume was equipped with two flow systems designated as the Strainer Flow Loop and the Heat Recirculation Loop. To reduce the hydrostatic forces on the plywood walls, water was added on both sides of the flume testing section in order to prevent the flume wall from collapsing due to high pressures from the water inside the flume. The flume was filled with city water using a two inch diameter hose and was drained into waste water storage tanks using the elevation head of the flume.

The Strainer Flow Loop was constructed from four inch and eight inch diameter schedule 40 PVC piping and contained a 20 HP variable speed centrifugal pump with a-rated capacity of 1500 GPM at 40 ft of head. During testing, flow from the strainer was discharged to the upstream end of the flume through an orifice meter. The loop was designed to provide strainer flow rates from 75 GPM to 210 GPM and measure pressure differentials across the test strainer ranging from 0.02 ft of water to 20 ft of water.

The Heat Recirculation Loop was used to heat and maintain the flume water temperature at approximately 120 deg. F, with a variance of approximately 20 deg. F.

The loop contained a heat recirculation pump and a 800,000 BTU/hr heat exchanger. A secondary closed loop system, consisting of a separate pump and a boiler, supplied the heat input for the heat exchanger. Once the water temperature reached - 120 deg. F,.

the boiler was shut down and the Heat Recirculation Loop isolated. Water temperature was maintained during the tests using immersion heaters installed in the upstream end of the test flume.

Flow meters used in the testing were calibrated using the weight time method in the ARL meter calibration facility, which is traceable to the National Institute of Standard and Technology (NIST). Calibration curves for each meter were used in the data recording to calculate flows in gallons per minute. The calibration interval for flow meters was in accordance with ARL's calibration procedures.

An automated data recording system was able to read the output of four differential '

pressure cells to record the flow through the flow meters and the pressure differential across the strainer. Each cell was calibrated using a NIST traceable dead weight tester.

Each cell used during a test was checked against a micro manometer at two deflections before the test was started. The cell calibration interval was in accordance with ARL's calibration procedures.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 42 of 77 Water temperature measuring devices were checked against a NIST traceable temperature device using a controlled temperature bath adjusted to provide temperatures over the range encountered during the strainer study.

A 200-lb capacity scale was used for weighing debris in a dry state.

All instrument calibration intervals were as stated in ARL's calibration procedures.

Test Conditions (F.19.c.xi)

The test flume volume was 238.1 ft3 (1781 gal) and the piping volume was 30.79 ft3 (230 gal) for a total liquid volume of 268.89 ft3 (2011 gal).

The water level for the tests was 40.5 inches (3.375 ft) with 3.25 inch strainer submergence. This was more conservative than plant conditions: minimum sump level of 43.44 inches and strainer height of 37.25 inches resulting in 6.19 inch submergence.,

The flume width was determined by a flume wall calculation performed by ARL. The flume was constructed with varying widths to obtain the average approach velocities to the strainer at distances to the strainer up to 30 ft. This included the increased velocity over the debris interceptor.

Flow through the strainer module in the test flume was 136.9 GPM (0.305 ft3/sec). This flow rate is equivalent to 1920 GPM through the strainer during the design basis event (1870 GPM, plus 50 GPM added for margin). The velocity through the strainer module was 0.0056 ft/sec.

Debris Preparation (F.19.c.iii)

The following table displays the test materials, surrogates and how they were processed for the tests.

Note: As indicated in Attachment 1, following removal of the fibrous insulation on the pressurizersurge line pipe whip restraintsand the Service Water piping in RCS Loop B Vaults, the remainingdebris inventory applicable to the tested materialsare:

Thermobestos, Okotherm cable insulation, latent debris, coatings and chemical debris (see Attachment 1, Table B-3). However, all materials tested are included in this table for completeness.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 43 of 77 MATERIAL/SIZE TEST SURROGATE HOW PROCESSED TempMat - Fines TempMat raw fibers from Dry shredded with food processor manufacturer prior to or similar needling TempMat - Smalls TempMat blanket Cut into pieces sized to fit through 1x4 opening Fiberglass Pipe Cover - Owens Corning fiberglass Dry shredded with food processor Fines or similar Fiberglass Pipe Cover - Owens Corning fiberglass Processed through leaf shredder; Smalls pieces small enough to pass through 1x4 grid Okotherm cable insulation TempMat raw fibers from Dry shredded with food processor

- Fines manufacturer prior to or similar needling Okotherm cable insulation TempMat blanket Cut into pieces sized to fit through

- Smalls 1x4 opening Thermobestos (Calcium TempMat blanket Cut into pieces sized to fit through silicate w/asbestos fibers) 1x4 opening

- Fibrous portion (10%)

Latent fibers - Fines Nukon Dry shredded with food processor or similar Thermobestos (Calsil Calcium silicate Pulverized powder w/asbestos fibers) -

particulate portion (90%)

Latent particulate PCI PWR Dirt Mix Small < 75 microns (37%)

Medium 75 to 500 microns (23%)

Large 500 to 2000 microns (40%)

Coatings - Zinc Tin Powder Powder form Coatings - Epoxy, Acrylic Powder Powder form Enamels Coatings - Epoxy outside Acrylic Chips 1/64" to 1/4" chips ZOI Chemical Debris Sodium Aluminum Silicate WCAP AIOOH Surroqate Debris Characteristics (F.19.c.iv., F.119.c.xii)

Actual debris materials were used where possible. A description of the surrogate materials used is documented in SFSS-TD-2007-004, Sure-Flow Suction Strainer -

Testing Debris Preparation & Surrogates, Rev. 0. This document was submitted previously by PCI to NRC in accordance with 10 CFR 2.390 (note it is marked Proprietary and Confidential).

Surrogate debris was density-corrected. Weight conversions were applied to the surrogates (e.g., Ibs/ft3). The debris quantities were then scaled to the test volume.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 44 of 77 Tin Powder PCI's review of tin powder found it to be stable, not easily oxidized in air, resistant to corrosion and incompatibilities (i.e., halogens, halogen trifluorides, nitric acid, sodium peroxide, sulfur, copper nitrate, hydrochloric acid, tin chloride, sodium peroxide, and potassium peroxide), slow reacting when heated in air, and have no reaction with cold water or when heated in steam, have very slow reaction with dilute hydrochloric acid, and have very slow reaction with diluted sulfuric acid.

Owens-Corning Fiberglass pipe insulation (pipe cover) with an original manufactured density of 3.5 - 5.5 lb/ft3 was used as the surrogate material for fiberglass since it has a higher density than other types of fiberglass.

Latent Fiber Latent fiber debris exists primarily in the form of Fines from unknown sources, but may include fiberglass insulation, fiberglass cloth, fibrous cloth, and protective clothing, among other similar type materials. Although Kewaunee does not have NUKONR insulation in Containment, NUKON insulation was used as the surrogate material for latent fiber since it has similar debris characteristics. NUREG/CR-6877 indicates that NUKONfibers are comparable to plant latent fiber samples.

Calcium Silicate Powder IIGThermo-12calcium silicate insulation was procured by PCI from the manufacturer.

The product is standard thermal insulation calcium silicate block material that meets ASTM C533-95 and has a density of 14.5 lb/ft3. The product was purchased directly from the manufacturer in a pulverized form.

Acrylic Chips Coating debris specified as chips was formed from Carboline Carboguard 890 dry film coating. Chips used in Kewaunee testing were sized between 1/64" and 1/4".

Sodium Aluminum Silicate Kewaunee's chemical precipitate formed in the sump pool is sodium aluminum silicate (NaAlSi308). Because NaAlSi308 is considered a hazardous material, aluminum oxyhydroxide (AIOOH) was used in lieu of NaAlSi308 for the tests. This surrogate is acceptable as indicated in Section 7.3.2 of WCAP-16530-NP Rev. 0. The chemical precipitates were generated using the methodology in WCAP-16530-NP and the final Safety Evaluation Report, WCAP-16785-NP, and PWROG letter OG-07-270. The DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 45 of 77 chemical materials were generated in mixing tanks and introduced into the test flume within the parameters provided in the PWROG letter OG-07-270.

PWR Dirt Mix (Latent Particulate)

PCI blended three different silica sand products and achieved:

Small < 75 microns (37%)

Medium 75 to 500 microns (23%)

Large 500 to 2000 microns (40%)

Procedure Steps (F.19.c.v) and Debris Introduction Sequence (F.19.c.i)

Prior to conducting the strainer debris head loss tests, a clean strainer head loss (CSHL) test was conducted. Upon obtaining the CSHL test data, the test continued to perform a transport test of select miscellaneous debris materials. The materials that were found not to transport were not placed in the test flume during the debris bed head loss tests to avoid it capturing other debris, such as fibrous debris, and prevent its movement toward the strainer. The CSHL and transport test procedure steps were as follows:

CSHL and Debris Transport Tests

1) Verify flume and piping have been cleaned and free of residual debris

2) Fill flume to designated water level and heat to 120 OF

" document water level

• manually verify strainer submergence depth

" record water level and strainer submergence

3) Start recirculation pump and obtain 75 GPM flow rate

4) Maintain the strainer flow rate and monitor head loss through the strainer

5) Manually record on 2 minute intervals

" flow rate

" water temp

" dp across strainer

6) Measure and record the pH of the flume water; observe strainer for vortexing

7) Increase strainer flow to next incremental value (target flow rates: 75, 136.9, 175, 200 and 215 GPM)

8) Repeat steps 4 through 7; end of CSHL test

9) Adjust flow to design basis flow rate (136.9 GPM)

Note: Debris drop zone was located - 29 ft upstream of leading edge of strainer

10) Add miscellaneous debris samples at the upstream end of the flume (1/4" x 1/4" RMI, 1/2" x 1/2" RMI, 1" x 1," RMI, 3 in. strip of Y2" width Dymo label, 7 in. strip of Y2" DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 46 of 77 Dymo label, 3/4" plastic decal, -12 in. piece of plastic decal, -3 in. piece of plastic decal, 3/4" x 3/4" piece of electrical tape, 7 in. tie wrap, -3.5 in. tie wrap, 1," x 4" paper labels, 1" x 2.5" Brady labels)

11) Run the test for at least one full pool turnover or until debris settles on flume floor

12) Document the miscellaneous debris location in relation to the drop zone

13) Terminate the test The following procedure was used for the strainer debris bed head loss design basis case (labeled "Test 3"). The duration of Test 3 was just over 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. The test was repeated a second time at design basis conditions with additional debris added to the flume for debris inventory margin (labeled "Test 9"). Test 9's duration was also - 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Debris Bed Strainer Head Loss Tests

1) Verify flume and piping have been cleaned and free of residual debris

2) Prepare debris (see 19.c.iii)

" non-chemical debris is weighed dry

" separate non-chemical debris by type and size into individual batches

" combine each batch with hot water (120 IF)

" fine fibrous debris:

o mix with 3 parts water to 1 part fibrous (by volume) o fill 5 gal. bucket w/3 gal. hot water o place 1 gal of pre-mixed fine fiber into 5 gal. bucket o remix 5 gal. bucket with paddle mixer or similar o repeat until all fine fibrous is diluted

3) Fill flume to designated water level and heat to 120 OF

• document water level 0 manually. verify strainer submergence depth

• record water level and strainer submergence 0 check immersion heaters periodically for debris accumulation

4) Prior to starting pump, add 25% of latent fine fibrous; this debris is evenly distributed throughout the lenqth of the test flume by pouring from its mixing container; rinse container with city water to ensure all debris entered into flume

5) Wait 5 minutes

6) Start recirculation pump (design basis flow rate)

7) Measure and record pH of flume water; observe strainer for vortexing

8) Manually record on 2 minute intervals

• flow rate

" water temp DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 47 of 77

" differential pressure across strainer

" observation for vortexing

" observation for bore hole formation

" additional information as appropriate

9) Insert all fine particulate debris

10) Insert all/remaining fine fibrous Note: Debris in the test flume was not manually or mechanically stirred.

(F.19.c.xiii)

11) Wait at least one pool turnover

12) Insert all small particulate

13) Insert all small fibrous

14) Wait at least one pool turnover 0 maintain flow rate 0 monitor head loss

15) Measure and record pH; observe for vortexing

16) Insert chemical debris; 51 batches inserted incrementally over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 0 33% of base chemical concentration was added in increments. pH of the flume water is measured and recorded when approximately 25%, 50%, 75% and 100%

of this debris is added. Head loss is monitored for at least two pool turnovers.

• The process is repeated for the next two batches (66%, 99%).

0 At this point, the flume volume concentration is essentially met.

• An additional 20% of the base chemical concentration is added to the flume to compensate for chemical debris that may have settled or captured in the debris bed to ensure the flume volume chemical concentration is maintained. These 20% additions continue until the full amount of chemical is added.

• The chemical debris storage tanks and lines are rinsed and flushed to ensure the total chemical debris is added in the flume.

17) Terminate the test when the change in head loss is less than 1% in the last 30 minute time interval, and a minimum of 15 flume turnovers occurred after all the tested debris is inserted into the test flume.

Debris Introduction Techniques (F.119.c.vii)

Latent Debris (initial flume introduction) (F.19.c.ii) 25% of the latent fibrous debris, represented using fine Nukon fibers, was added to the test flume prior to starting the recirculation pump. This debris was evenly distributed throughout the length of the test flume by pouring from its mixing container. Prior to placement in the flume, the latent fibers (Fines) were mixed in hot 120 deg F water, three parts water to one part fibrous debris by volume. The container was then rinsed DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 48 of 77 with tap water and emptied into the flume to ensure all debris entered the flume. After a hold time of five minutes, the flume recirculation pump was started.

RAI F.19.c.ii, and a follow up teleconference with NRC staff on September 15, 2009, questioned whether adding 25% latent fiber prior to starting the pump would allow the fiber to settle and limit its transport to the strainer. RAI F.19.c.ii is no longer applicable since the new debris inventory described in Attachment 1 to this letter specifies a new maximum allowable latent debris quantity that is bounded by the quantity of latent debris added to the test flume after the recirculation pump was started. No other debris was placed in the flume prior to starting the recirculation pump, or at a reduced flow rate.

Other Non-Chemical Debris (F.19.c.xv)

Non-chemical debris was retained in separate containers, segregating the debris by both type and size. 120 deg F water was added to each container to aid in removing trapped air bubbles. The debris was mixed using a mechanical paddle mixer or similar:'

This debris was introduced into the flume in accordance with the procedure direction through the "drop zone", approximately 29 ft upstream of the leading edge of the strainer module. The containers were rinsed with tap water and emptied into the flume to ensure all debris entered the flume.

Agglomeration of the debris was prevented by preparing and maintaining the debris by size and type in separate containers until addition to the flume (see F.19.c.iii). The debris addition was sequenced with time between debris additions to prevent agglomeration. There was one full pool turnover between adding fine debris and small debris, and again between adding small debris and beginning chemical debris addition.

See also available photos of the debris preparation (Enclosure B for Questions 5/6/7/12) and debris addition (Enclosure H).

Chemical Debris The base chemical concentration for Kewaunee "Test 3" (design basis debris load) was 12.51 Ibm sodium aluminum silicate (NaAlSi308) (AIOOH surrogate). Using a 7.129%

scaling factor, 0.93 Ibm at 11 grams/liter was placed in the test flume.

When directed by procedure, the chemical debris was introduced as follows:

51 batches were inserted incrementally over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />

• 33% of base chemical concentration was added in increments. pH of the flume water was measured and recorded when approximately 25%, 50%, 75% and 100% of this debris was added. Head loss was then monitored for at least two pool turnovers.

• The process was repeated for the next two batches (66%, 99%).

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Serial No.10-025 Attachment 2 Page 49 of 77

• At this point, the flume volume concentration was essentially met.

" An additional 20% of the base chemical concentration was added to the flume to compensate for chemical debris that may have settled or captured in the debris bed to ensure the flume volume chemical concentration was maintained. These 20% additions continued until the full amount of chemical was added.

" The chemical debris storage tanks and lines were rinsed and flushed to ensure the total chemical debris was added in the flume.

The strainer debris bed head loss test was repeated "Test 9" (design basis debris load with additional debris for margin) and 200% chemical addition was used for this test.

Therefore, the chemical concentration was 25.02 Ibm sodium aluminum silicate (NaAlSi308) (AIOOH surrogate). Using a 7.129% scaling factor, 1.86 Ibm at 11 grams/liter was placed in the test flume using the same chemical debris introduction sequence listed above.

Chemical concentration worksheets for Test 3 and Test 9 are included as Enclosure J.

Quantity of Debris Added to the Test Flume (F.19.c.ix)

The following table displays the debris added during the design basis tests.

TEST3QTY TEST 9 QTY MATERIAL SIZE (DESIGN (DB TEST BASIS TEST) W/ADD'L DEBRIS)

TempMat Fines 4.95 FT3 5.4 FT3 TempMat Smalls 5.95 FT3 6.5 FT3 Fiberglass Pipe Cover Fines 0.44 FT3 0.88 FT3 Fiberglass Pipe Cover Smalls 1.56 FT3 3.12 FT3 Okonite Cable Insulation Fines 0.23 FT3 0.23 FT3 Okonite Cable Insulation Smalls 0.33 FT3 0.33 FT3 Calsil fiber Fines 0.054 FT3 0.054 FT3 Latent fiber Fines 6.25 FT3 6.25 FT3 Calsil particulate Pulverized powder 0.486 FT3 0.486 FT3 Latent particulate Small < 75 microns (37%) 85 LBM 100 LBM Medium 75 to 500 microns (23%)

Large 500 to 2000 microns (40%)

Zinc coatings Tin powder 0.8424 FT3 0.8424 FT3 Epoxy coatings Acrylic Powder 1.3 FT3 1.3 FT3 Epoxy coatings Chips 0.09 FT3 0.09 FT3 Enamel coatings Acrylic Powder 3.3783 FT3 3.3783 FT3 AIOOH WCAP 12.51 LBM 25.02 LBM DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 50 of 77 Debris Quantity Added per Each Debris Addition Latent Fines - 25% added prior to pump start (see F.19.c.ii)

Chemical Debris - administered in 51 batches (see F.19.c.vii)

All other debris additions - total/remaining debris quantity added (not in increments) -

see F.19.c.v and F.19.c.i above Location of Debris Addition wrt Other Equipment With the exception of 25% of the latent Fines addressed in F.19.c.ii, the debris was introduced into the flume through the "drop zone", approximately 29 ft upstream of the leading edge of the strainer module. A debris interceptor (C8x1 8.75 channel) was present in the flume, 1.4 ft upstream of the leading edge of the strainer. There were no other equipment in the flume.

Thin Bed of Fiber (F.19.c.viii)

Kewaunee did not perform a thin bed test in the large scale flume in 2008. Instead, the large scale flume tests were used to determine the actual debris transport and strainer head loss at the design basis flow rate. A thin bed of fiber did not form during these tests.

In 2007, fiber transport tests were performed in the 20' 11" x 27" ARL flume. A debris interceptor was modeled in the flume and the flow rate was equal to the maximum flow rate over the debris interceptors as determined by a CFD. In this test, a thin bed of fiber did not form on the strainer.

In 2006, a thin bed flume test was performed in the 20' 11" x 27" ARL flume by placing enough Nukon Fines into the flume until a 1/8" bed of fiber was formed on the strainer.

The pump flow rate was equivalent to 4000 GPM, more than two times the design basis flow rate through the strainer. All particulate debris was placed in the flume. Chemical debris was inserted, equivalent to 665 mg/L NaAlSi308, in powder form. Measured head loss was 2.3 ft of water (temperature corrected to 65 deg F). Total head loss was 2.3 ft + 1.45 CSHL = 3.75 ft, which remained significantly below the 10 ft allowable head loss.

Results (F.19.c.xiv)

The results of the clean strainer losses plus strainer debris losses remained well below the 10 ft of water allowable total head loss. See response to Questions 19.b and 23 for the quantitative results.

The CSHL test plots (raw data, prior to temperature correction) are included in Enclosure I-1.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 51 of 77 The miscellaneous debris items placed in the test flume to document their transport (labels, etc.), were all found to settle in the flume between 4 ft and 14 ft past the drop zone and therefore, was excluded from the strainer debris bed head loss tests. The strainer debris bed head loss tests included fibrous, particulate and chemical debris.

• The test plot for "Test 3", with the design basis debris load, is included in Enclosure 1-2.

" The test plot for "Test 9", with additional debris load for added margin, is included in Enclosure 1-3.

Similar to the CSHL plot, the Test 3 and Test 9 plots depict raw test data (without temperature correction).

Upon draining the test flume, it was observed that nearly all debris, with the exception of chemical debris and suspended fibers, settled in the test flume, well upstream of the debris interceptor. Small and Fine TempMat debris was found near the drop zone, other fibrous debris was found a few feet beyond the drop zone, and some Fine fiber was found on the upstream side of the debris interceptor. See photos in Enclosure 1-4.

NRC Question 20 Please provide a vortexing evaluation including test conditions, assumptions, and their basis. Include any additional vortexing evaluation that was conducted not based on test observations.

Response

During the large scale flume tests conducted in August 2008, the flume test procedure specified observing the strainer on regular intervals during the test for signs of vortexing (see response to F.19.c.v.). No vortices were observed during the debris bed head loss tests.

Additionally, PCI performed a vortex evaluation for the Kewaunee strainer design. The evaluation is included as Enclosure K. The largest opening for water to enter the recirculation sump pit where the RHR pumps take suction is 0.066 inch diameter holes in the strainer assembly. The size of the perforated plate holes will preclude formation of a vortex. The strainer module internal design includes wire stiffeners with small openings inside the strainer that directs flow to the core tube and ultimately the sump pit. These obstructions and small clearances will also prevent a vortex formation.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 52 of 77 NRC Questions 21 & 22 Please provide the conditions assumed for the voiding evaluation and their bases.

Please include an evaluation for the potential of degasification of the sump fluid as it passes through the debris bed.

Provide the conditions assumed for the evaluation of flashing in the strainer and their bases. Please provide the margin to flashing for each condition considered.

Response

Void formation is the result of the pressure of a fluid being reduced below the saturation pressure with the resulting voids being formed by the flashing of the liquid phase. Air does not need to be present to create significant voiding.

Evaluation TDI-6008-07, Revision 6 (Enclosure K), includes an evaluation for air ingestion. Air ingestion is evaluated and results in a Froude Number for the Kewaunee strainer that is substantially less than the guidance stated in Regulatory Guide 1.82, Revision 3. Air ingestion is not expected to occur in Kewaunee's strainer due to having a low Froude Number, a lack of an air entrainment mechanism (no vortex formation),

and complete strainer submergence.

TDI-6008-07, Revision 6 (Enclosure K) also evaluates for void formation. The evaluation uses a conventional hydraulic and fluid flow calculation and concludes 0%

void fraction in the strainer discharge flow.

TDI-6008-07, Revision 6 (Enclosure K) also evaluates for flashing at the strainer debris bed and gas evolution (deaeration) downstream of the strainer. The evaluation concludes any void fraction that could occur at the strainer debris bed would be very minimal and the voids caused by flashing at the strainer will have collapsed before they enter the recirculation pump inlet lines. It also concludes that due to the significant elevation difference between the sump outlet and recirculation pump inlet, re-initiating void fraction downstream of the sump outlet is not possible.

NRC Question 23 Please provide head loss plots for the testing including annotations of relevant steps in the tests.

Response

Head loss plots are included as Enclosures 1-1, 1-2 and 1-3. The test plots provide the raw test data prior to temperature correction. See response to Question 19.b for a tabulation of the strainer losses.

a Enclosure I-1 provides the clean strainer head loss test plot.

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Serial No.10-025 Attachment 2 Page 53 of 77

" Enclosure 1-2 provides the strainer debris bed head loss test plot at the design basis flow rate and with the design basis debris load.

• Enclosure 1-3 provides the strainer debris bed head loss test plot at the design basis flow rate and with the design basis debris load supplemented by revising the chemical debris load to 200% the design basis value, and with additional insulation and latent debris for additional debris load margin.

For all cases, the more conservative temperature-corrected strainer head loss (clean strainer and debris bed losses combined) remained significantly below the allowable 10 ft of water loss.

NRC Question 24 Please provide information on whether the strainer is vented.

Response

The recirculation strainer is self-venting by design. The strainer is located on the Containment basement floor elevation. The strainer empties into the sump pit where the RHR pumps take suction. The Containment basement will flood during the LOCA event and the sump pit begins to fill when the Containment basement water elevation reaches 9.5 inches above the basement floor elevation, when water begins to enter the strainer's inner core tube and empty into the sump pit. The strainer core tube has a slotted design around its circumference that allows air to escape out the upper half of the core tube and strainer as the pit and strainer exit piping fills. The strainer is fully submerged prior to the RHR pump being started in the recirculation mode.

NRC Question 25 Please provide the head loss test termination criteria. Include test data that verifies the criteria were met.

Response

The PCI test protocol specified terminating the test when the change in head loss was less than 1% in the last 30 minute time interval, and a minimum of 15 flume turnovers occurred after all the tested debris has been inserted into the test flume. In both strainer head loss tests (Test 3 w/design basis debris load, Test 9 w/additional debris load - see F.19.c), the maximum measured strainer head loss occurred at or just after 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br /> of flume operation. The test termination criteria was met approximately two hours later in each occurrence and the strainer head loss was decreasing (see Test 3 and Test 9 plots in Enclosures 1-2 and 1-3).

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 54 of 77 NRC Question 26 Please provide any extrapolation of head loss test results to the plant strainer mission time and the methodology used. Please provide adequate data that the staff can verify that the extrapolation was performed conservatively.

Response

At 26 hours3.009259e-4 days <br />0.00722 hours <br />4.298942e-5 weeks <br />9.893e-6 months <br /> and 49 minutes after the start of the Design Basis Test (Test 3), the last chemical debris batch was inserted into the flume. The test continued for another three hours and 49 minutes (from 26:49 to 30:38). After inserting the final chemical batch, the head loss climbed slightly as expected, then leveled off and began to slowly decrease over the last three hours of the test. With the full debris load in the recirculation sump and head loss continually decreasing, an extrapolated decrease in head loss was not calculated. The design basis test with additional debris load (Test 9) had similar behavior. Test 3 and Test 9 plots are included as Enclosures 1-2 and 1-3.

NRC Question 27 Please provide a schematic representation of the test flume that includes relevant measurements and articles within the flume.

Response

Kewaunee's large scale flume arrangement is shown in Enclosure G. Debris introduction occurred 29 ft upstream of the leading edge of the strainer module. A debris interceptor, C8x1 8.75 channel, was mounted 3/8 inch off the flume floor to replicate Containment conditions, and was placed 1.396 ft upstream of the strainer.

NRC Question 28 Please state whether any debris interceptors were included in the head loss testing. If debris interceptors were included in the testing, please provide details of how the debris interceptors are installed in the plant and how the interceptors were installed in the test flume. Please provide adequate details so that the staff can evaluate the prototypicality of the test setup against the plant.

Response

See response to Question F.27 for the flume design, including placement of the debris interceptors in the flume. See Enclosure D for a pictorial layout of the debris interceptors as they are installed in the Containment basement (sump).

The debris interceptors installed in the plant are constructed from C8x1 8.75 channel and are mounted on 3/8 inch steel plate. The same material and mounting was used in the flume design.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 55 of 77 The flume wall calculation evaluated the placement of the debris interceptor in the flume and determined the flume wall width necessary to achieve the desired flow velocity, 0.138 ft/sec, over the debris interceptor. Considering the debris interceptor placement in the flume 1.396 ft upstream of the strainer module, and an effective water height above the debris interceptor equal to 2.677 ft, a required flume width of 0.829 ft at the debris interceptor was determined. Therefore, the flume wall width contracted slightly at the debris interceptor placement to achieve the desired flow velocity at that location.

The flow rate over the flume debris interceptor, 0.138 ft/sec, is the weighted average flow velocity over the three debris interceptors installed in the plant. However, the CFD flow patterns indicate the majority of the flow towards the strainer approaches the strainer from the south, over the south debris interceptor. The average flow velocity over the south debris interceptor is 0.111 ft/sec, therefore, the flume design is conservative. See also response to Question 15.

G. Net Positive Suction Head (NPSH)

NRC Question 29 The basis for the stated design flow rates for the residual heat removal (RHR) pumps was not provided. Please provide the methodology and assumptions for the calculation of these flow rates.

Response

One RHR pump operates in the recirculation mode, resulting in flow through the recirculation strainer at 1870 GPM and flow through the pump at 1990 GPM (includes pump recirculation flow). 1920 GPM flow through the strainer (1870 GPM, plus 50 GPM margin) was specified as the flow rate for the large scale flume tests.

Fluid flow analysis program PROTO-FLO, Version 4.5, was used to model the recirculation system and determine these flow rates. The maximum flow through the recirculation strainer was determined conservatively assuming the RHR pump discharge throttle valve (RHR-8A/B) is failed in the full open position. A high sump level of 6 ft is used in the analysis to provide a conservative high flow rate. The Containment temperature is assumed to be 210 deg. F and Containment pressure at 35 psia.

Pressure drop through the sump strainer is assumed to be negligible to result in a higher RHR flow rate. The RHR pump is assumed to be operating on the vendor's shop test (certified) pump curve, rather than in a degraded condition. The reactor vessel/RCS pressure is assumed to be the same as the Containment pressure to maximize RHR flow. An additional 10% conservatism (uncertainty) is applied to the calculated flow rate. As indicated in our December 18, 2008 response, the resultant flow rate through the recirculation strainer with one RHR pump taking suction from the sump is 1870 GPM. The flow through the RHR pump was conservatively calculated as DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 56 of 77 1990 GPM, which includes flow through the strainer plus pump recirculation flow. The flow rate through the strainer, 1870 GPM, was conservatively increased to 1920 GPM for conducting the 2008 large scale flume tests.

NRC Question 30 The basis for the NPSH required for the RHR pumps at the design flow rate was not provided. Please provide the basis for the RHR pump NPSH required, including any assumptions or acceptance criteria used by the pump vendor.

Response

Kewaunee's RHR pumps are Byron Jackson, Type 6 x 10 x 18 Vertical V-DSM.

NPSH required (NPSHR) is 8 ft of water at 2000 GPM. This was determined from the original manufacturer pump curves, Byron Jackson Tests T-32129 and T-32130. The vendor pump tests were performed at 1770 RPM and 2000 GPM. Total developed head was 280 ft of water at 80% pump efficiency.

2000 GPM exceeds the design basis flow rates through the RHR pumps. The design basis flow through the RHR pumps is 1990 GPM when supplying the reactor vessel in the Containment sump recirculation mode (see response to Question 29). One RHR pump operates in the recirculation mode in response to the design basis event.

NPSH margin based on most recent tests and calculations is as follows:

PARAMETER HEAD COMMENT (FT)

NPSH Available 24.108 Total water height at the onset of recirculation, minus piping friction losses [26.224 - 2.116]

Maximum measured 3.28 Includes clean strainer head loss, debris laden strainer strainer discharge piping losses and head loss debris bed losses combined (Notes 1, 2)

NPSH Required 8 At design flow rate 2000 GPM NPSH Margin 12.828 Note 1: The ECCS recirculation strainer design is limited to 10 ft head loss at 4000 GPM, unless the structural integrity of the strainer is analyzed to exceed that value.

Note 2: The maximum measured head loss through testing is 3.28 ft of water (see response to Question 19.b).

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 57 of 77 NRC Question 31 The methodology for the calculation of suction line friction head losses for the NPSH calculations was not provided. Please provide the NPSH calculation methodology along with the calculation's assumptions and the bases for these assumptions.

Response

Piping friction losses were calculated using the Darcy-Weisbach formula. The losses were calculated for the RHR pump suction line from Containment to the pump suction.

The suction piping includes the inlet pipe bell, suction piping, Containment isolation valves, and pipe fittings.

In the calculation, the sump water temperature is assumed to be 700 F. Although the sump water temperature would be much greater than 700 F when the RHR suction supply is switched over from the RWST to the Containment sump, using a lower fluid temperature resulted in greater piping head losses due to friction in the suction piping.

This assumption is conservative in that it results in lower NPSH available (NPSHA) at the RHR pumps because of the higher calculated friction losses.

The friction losses were calculated with an assumed flow rate 2000 gpm, which is the design flow point for the RHR pump. This assumption is conservative as the maximum flow through the suction piping is less than 2000 gpm (see response to Question 33).

The relative roughness of the suction piping is assumed to be consistent with new clean commercial steel pipe. The RHR system piping is stainless steel which is not readily susceptible to corrosion.

The following equation expresses the frictional losses term (hfs):

hfs = hstrainer + 2'hpipe Where, hstrainer = head loss across the strainer (in feet)

Jhpipe = sum of friction losses through piping, valves, and fittings at rated flow (in feet)

The general equation for frictional losses through a pipe (pressure drop), known as Darcy's formula and expressed in feet of liquid, is:

2 h LV D 2.g DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 58 of 77 Where, f = friction factor L = equivalent length of pipe (in feet)

V = mean velocity (in feet per second)

D = internal diameter of pipe (in feet) 2 g = acceleration of gravity = 32.2 feet/sec The friction factor (f) is a function of Reynold's Number (Re) and the character of the pipe wall (relative roughness). Reynold's Number is defined as (dimensionless):

Re - g Where, p=62.3--b @ 70 deg. F V = velocity of fluid (feet/sec)

D = inside pipe diameter (feet)

=20.10-5 Ibfsec ft 2 @ 70 deg. F 2

g = acceleration of gravity = 32.2 feet/sec The relative roughness of the pipe is defined in Crane Technical Paper 410 as:

Relative Roughness = F- / D Where, F= 0.00015 ft [for commercial steel pipe]

D = inside pipe diameter (feet)

When Reynold's number and relative roughness are known, the friction factor (f) is read from the Moody chart published on page A-25 of Crane Technical Paper 410.

The RHR pump suction piping from the Containment sump is segregated into three sections for the purposes of calculating friction losses. Those sections are:

• from the suction pipe end bell in the sump pit to the first isolation valve (14 inch diameter; called RUN 1)

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 59 of 77

" from the first isolation valve through the second isolation valve to a reducer (12 inch diameter; called RUN 2)

" the pipe from the second isolation valve to the RHR pump suction (10 inch diameter; called RUN 3)

The results of the calculated friction losses for RUN 1 are as follows:

RUN 1

• p.Q .D1 s Rei s , A-s* )

g 3

S Ibf ft 62.3 - .4.465 .1.1042ft ftl sec 0.9576ft 2.05.10-5 Ibf.ft2sec 2

Reis = ft 32.2-sec2 Res = 4.86x10 5 Relative Roughness = E / Dis Relative Roughness = 0.00015/1.1042 Relative Roughness = 1.358x1 04 Using the Moody Chart on page A-24 of Crane Technical Paper 410, the friction factor corresponding with the Reynold's Number and relative roughness is:

fls = 0.0147 The results of RUN 2 equal 0.0148. The results of RUN 3 equal 0.0149.

The overall calculated friction losses from the sump suction to the RHR pump suction are:

Lis Q2 L2s Q2 L3s Q2

~hpipe = fi S 1 2 * +f2S* 5 2 *__2 +f

• hDis.As 2.g CD 2s.A 2s "g (D3sA 3s) 2-g 3

W 12 '-2 3s2 ft 4.465 4.465 _ (4.465 I Yh =0.0147- 106.488 ft sec) + 0.0148- 56.299_ft 4 6 +0.049. 65.740 ft 4 6sec_ 2 (1.1042ft.(0.9576ft2)f. 2.32.2 t + 4 0.995ft.(0.778ft)') 2-32.2 _+ 0.0 835ft.(0.548ft2Y)' 2.32.2 2

-'pi2 2 1 6f c see Jhpipe =2.116 ft DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 60 of 77 NRC Question 32 Differences between the conditions and assumptions for the small- and large-break loss of coolant accident cases were not provided. Please provide any differences in conditions for the small- and large-break loss of coolant accident cases or demonstrate one case to be limiting.

Response

(See response to Question 33 regarding recirculation flow paths and RHR pump flow rates.)

The NPSH evaluation for the RHR pumps operating in the recirculation mode is prepared for the bounding large break LOCA (LBLOCA) case.

Recirculation is assumed to be initiated at the 37% RWST level (tank 63% depleted).

This is the soonest recirculation can be initiated and is based on having two ECCS trains available. The 37% RWST level switchover to recirculation results in the lowest (most conservative) Containment sump water level. Additional details are provided below.

NPSH required is based on the RHR pump design flow rate of 2000 gpm. This is a conservatively high flow rate for either the LBLOCA or small break LOCA (SBLOCA) case. See response to Questions 29 and 33.

Containment atmospheric pressure is assumed to be equal to the vapor pressure of the sump water. This assumption is conservative in that it does not credit Containment pressurization to assist in the available NPSH to the RHR pumps during a transient and bounds both the SBLOCA and LBLOCA cases.

The head loss across the debris laden recirculation strainer is assumed to be at the maximum allowable 10 feet of water and bounds both the SBLOCA and LBLOCA cases.

Sump Level The minimum Containment water level at the start of recirculation is an input in determining the NPSH margin for the RHR pumps in the recirculation mode.

Kewaunee's minimum recirculation sump water level calculation evaluated two limiting scenarios.

Scenario 1 modeled a two inch or greater pipe break at or below the elevation of the RCS loops. Following the break in Scenario 1, the Containment volume begins to fill with pressurized steam, steam begins to condense on the Containment heat sinks, and a portion of the RCS water inventory spills to the Containment basement floor. The spilled RCS contracts when it reaches the cooler sump. The contraction is equal to the DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 61 of 77 ratio of the two water densities. The safety injection system takes suction from the RWST and delivers it to the reactor vessel. At the same time, the ICS system takes water from the RWST to provide spray to Containment. The injected water spills out the break onto the Containment basement floor and begins to fill Containment (waste)

Sump A and (recirculation) Sump B. The sprayed water initially accumulates on the upper Containment floors before cascading down to the Containment basement floor.

In Scenario 1 it is conservatively assumed that the safety injection accumulators do not discharge and the water in them is not added to the Containment sump level. This was conservatively assumed because there may be some small break LOCA scenarios where the RCS pressure does not drop below the accumulator pressure. The accumulators have a nitrogen cover charge and are maintained at approximately 750 psig. The minimum accumulator pressure allowed by plant Technical Specifications is 700 psig and minimum volume is 1225 ft3 (2450 ft3 total for two accumulators).

Scenario 2 modeled the equivalent of a two inch break at the top of the pressurizer. It is similar to Scenario 1 except that no water from the RCS inventory spills to the Containment floor. Instead, the volume of the pressurizer that is normally filled with steam becomes water solid. The reactor coolant system (RCS) pressure decreases to 700 psia after 1900 seconds, discharging the safety injection accumulators, and stabilizes at 550 psia after 2700 seconds. The water from the accumulators expands when it reaches the hotter, less dense sump water. The expansion is equal to the ratio of the two water densities. At 550 psia, the RWST injection flow into the RCS equals approx. 533 gpm. The internal containment spray injection flow rate with two trains running is approx. 2780 gpm. With a combined RWST injection flow rate of 3313 gpm, the available water volume in the RWST would deplete in approx. 2880 seconds.

Scenario 2 is not the limiting (lowest) sump water level scenario at the onset of recirculation as the accumulators are credited as contributing to the sump level. In the event the accumulators did not fully complete their discharge prior to starting recirculation, the sump water level would still be > 43.44 inches level calculated in Scenario 1, as the accumulators contribute 0.46 inches to the sump level when fully discharged and any quantity discharged results in a higher sump level than calculated in Scenario 1. (The small break LOCA analysis is documented in Kewaunee's Reload Transition Safety Report dated July 2002, and the Updated Safety Analysis Report, Section 14.3.)

In both scenarios, after Sump A and Sump B RHR pump suction pit (below the basement floor elevation) are filled, the water level above the Containment basement elevation begins to rise. When the water level reaches 2' 5" above the floor elevation, water spills into the inactive Sump C, below the reactor vessel. As Sump C fills, there is no change in the Containment basement sump water level until Sump C water level reaches the level in the basement. Then the water level in the Containment basement F (Sump B) and Sump C (below the reactor vessel) rises in response to additional water supplied from the RWST.

When the RWST is depleted to the switchover setpoint of 37% RWST level, the transfer to Containment sump recirculation begins. There is a delay before recirculation begins DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 62 of 77 due to operator response time required to perform the manual switchover actions.

During the switchover procedure, one ICS pump and one injection pump are shut down.

The operating pumps continue to deplete the RWST lower than 37% during the switchover to recirculation.

Hold up volumes were applied to both scenarios and are addressed in response to Question 34.

At the start of recirculation, the minimum sump water level for each scenario is as follows:

SCENARIO MIN. SUMP LEVEL STRAINER WATER LEVEL ABOVE BASEMENT HEIGHT (IN.) ABOVE STRAINER FLOOR ELEV. (IN.) (IN.)

Scenario 1 43.44 37.25 6.19 Scenario 2 43.9 37.25 6.65 Debris Generation SBLOCA vs. LBLOCA It is recognized that the Containment sump water level will be different for the scenarios mentioned above. It is also recognized that the amount of debris generated for the scenarios will be different, i.e., a LBLOCA will generate more debris (have a larger ZOI) than a smaller diameter pipe break. However, KPS analyses were prepared assuming the maximum debris generation (RCS Loop B hot leg break) and the minimum sump water level (which corresponds to a break of any size two inches or greater at or below the elevation of the RCS loops).

SBLOCA Emergency Operating Procedures specify performing a RCS cool down as fast as possible (but less than 100 deg F/hr) following a LOCA. Therefore, in response to a SBLOCA, it is quite feasible that the RCS could be cooled and depressurized during the RWST injection phase of the accident and Containment sump recirculation may not be required.

NRC Question 33 Please discuss the potential for differences between hot-leg and cold-leg injection flow rates and NPSH margins. Alternatively, please demonstrate that the evaluated case is limiting or that other cases are not required at Kewaunee.

DRAFT April 23, 2010

Serial No.10-025, Attachment 2 Page 63 of 77

Response

See response to Question 32 for the evaluated LOCA events for determining the minimum Containment sump water level which is an input to the NPSH margin evaluation.

In response to a large break LOCA with a depressurized RCS, the RHR pumps will feed the reactor core via the upper plenum (reactor vessel) injection line. In the recirculation mode, design basis flow through the RHR pump for this scenario is calculated as 1990 GPM, therefore, the NPSH required (NPSHR) 8 ft of water at 2000 GPM used in the NPSH evaluation is bounding. (Design basis flow through the recirculation strainer is calculated as 1870 GPM. Flow through the RHR pump includes pump recirculation flow. Pump recirculation discharges to the pump suction, downstream of the strainer.)

In response to a LOCA with the RCS greater than 150 psig, the Safety Injection pumps will feed the RCS via cold leg injection. The maximum Safety Injection flow to the core when piggybacked on a RHR pump is approximately 1265 GPM. This value, plus approximately 115 GPM RHR pump recirculation flow remains significantly below the NPSHR 8 ft of water at 2000 GPM used in the evaluation.

Kewaunee's emergency operating procedures do not specify use of hot leg injection.

In the NPSH margin evaluation, the Containment atmospheric pressure is assumed to be equal to the vapor pressure of the sump water. This assumption is conservative in that it does not credit Containment pressurization to assist in the available NPSH.to the RHR pumps during a transient.

The Containment sump water elevation is assumed to be 595.62 feet (43.44 inches of water above the Containment basement floor). This is the calculated minimum Containment sump water elevation at the start of recirculation. The RHR pump suction elevation is 569.396 feet, resulting in a difference of 26.224 feet. RHR pump suction friction losses are calculated as 2.116 feet of water, resulting in 24.108 feet of head available.

The head loss across the debris laden recirculation strainer is assumed to be at the maximum allowable 10 feet of water.

The NPSH margin for operating the RHR pump in the Containment sump recirculation mode with the assumed maximum allowable strainer losses was reported in our December 18, 2008 response and is reiterated below:

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 64 of 77 PARAMETER HEADCOMMENT (FT OF WATER)

Total water height at the onset NPSH Available 24.108 of recirculation, minus piping friction losses Maximum allowable debris Includes clean strainer head 10losadebibdhados laden strainer head loss (Note 1) combined NPSH required 8 At gmpmdesign flow rate 2000 gpm/pump NPSH margin 6.108 Note 1: See also table in response to Question 30.

NRC Question 34 Please identify the water sources and hold up volumes considered in the minimum water level calculation and provide quantitative values for each hold up volume for the limiting water level for the small- and large-break loss of coolant accident cases.

Response

Question 32 above describes the scenarios analyzed for determining the minimum recirculation sump water level, including description of the water sources.

The following table displays the hold up volumes that are included in the minimum recirculation sump water level calculation. All hold up volumes listed below were applied to both evaluated scenarios.

VOLUME (CU.F DESCRIPTION OF HOLD UP VOLUME (CU. FT.)

Waste Disposal Containment Sump A. The sump is below the 592' Containment basement floor (sump) elevation. It fills and remains 112.6 filled during the LOCA response scenario.

Sump B recirculation pit. The pit is below the 592' Containment basement floor (sump) elevation. The RHR pumps take suction from the Sump B recirculation pit. Although not a true hold up volume because this water is part of the recirculation sump, the sump is assumed to be empty at the start of the LOCA event. It fills with water 464.2 as Sump B (basement level) fills. Included in this volume is the initial fill of the RHR suction piping up to the second isolation valve (SI-351A/B).

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 65 of 77 VOLUME CU.F DESCRIPTION OF HOLD UP VOLUME (CU. FT.)

Containment Sump C. This sump is located under the reactor vessel.

Assuming the LOCA event does not occur at a reactor vessel nozzle (which is not a limiting break for debris generation), the sump will remain empty until the water level in the Containment basement floor reaches elevation 594'-5" or 2'-5" above the Containment basement elevation. At that time, Sump C begins to fill via the opening in the sump manway hatch. After sump C is filled to elevation 594'-5", the water level in Containment and sump C will continue to rise in 3,500 response to additional water supplied from the RWST. The volume of this sump at the point where the water level reaches the opening into Sump C is 3,764 cu. ft., less the volume of the flooded portion of the bottom of the reactor pressure vessel. At this point the hold up volume is approximately 3,500 cu. ft.

Hold up in the lowest elevation of refueling cavity due to the presence of a standpipe in the floor drain. 74.2 RWST volume to fill the normally empty portion of Internal 233 Containment Spray (ICS) piping and the ring header. f*

The volume of water from Containment Spray water droplets falling that have not reached the Containment sump. 41.1 Water held up at upper elevations of Containment on horizontal surfaces due to Containment Spray or condensation drainage. 1238.1 The steam and condensate mass in Containment as a result of the LOCA. 1008.1 TOTAL HOLD UP VOLUME (CU. FT.): 6,600 NRC Question 35 Please identify whether the emergency operating procedures would allow operators to manually operate two trains of RHR in recirculation mode. If this configuration is allowed, quantify its impact on the pumps' NPSH margin. Please provide similar information regarding the operation of the internal Containment Spray system in recirculation mode.

Response

The emergency operating procedures specify running one RHR pump in the recirculation mode in response to the design basis LOCA event.

The emergency operating procedures allow starting a second RHR pump in the recirculation mode to provide recirculation spray in response to a beyond-design basis DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 66 of 77 event (increasing containment pressure and less than two fan coil units operating). The beyond-design-basis event is not addressed in this response.

H. Structural analysis NRC Question 36 In accordance with the first portion of Section 3.k of the Revised Content Guide for Generic Letter 2004-02 Supplemental Responses, licensees were requested to provide the design code of record used in the structural qualification of their replacement strainer components. The licensee did not provide this information in the supplemental responses. Please provide the applicable code(s) of record for the qualification of the strainer modules, piping, piping supports, Sump B pit cover, Sump B pit maintenance hatch strainer, and any other applicable components.

Response

The strainer modules are mounted to the Containment basement floor elevation. The discharge of the strainer is piped to the recirculation sump pit where the residual heat removal pumps take suction. Adjacent to the piping sump pit entrance, a maintenance hatch strainer is positioned on the top of the sump pit. The maintenance hatch strainer is not credited in the design basis accident strainer surface area.

The strainer modules and maintenance hatch strainer, including the strainer mounting tracks and support channels that span across the sump pit, were evaluated using a combination of manual calculations and finite element analyses using the GTSTRUDL computer program, Version 25, and the ANSYS computer program, Version 5.7.1.

The strainer discharge piping and pipe supports, and sump cover plate (pipe entry into Sump B, recirculation sump pit), were evaluated using a combination of manual calculations and computerized analysis using the AutoPIPE Program, Version 8.50.

The strainer and related components were designed, fabricated and evaluated to USAS(ANSI) B31.1, Power Piping, 1967 Edition.

NRC Question 37 In accordance with the second portion of Section 3.k of the Revised Content Guide for Generic Letter 2004-02 Supplemental Responses, licensees were requested to provide the design margins for the strainer components which were analyzed for structural adequacy. Please provide and summarize, in tabular form, the design margins and/or interaction ratios for the strainer components analyzed for resolution of GL2004-02.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 67 of 77

Response

The requested information is included as Enclosures L-1 and L-2, with photos of the strainer assembly included to aid the review.

Enclosure L-1 is from the structural evaluation of the strainer modules and maintenance hatch strainer, including the strainer mounting tracks and support channels that span across the sump pit.

Enclosure L-2 is from the structural evaluation of the strainer discharge piping, pipe supports and sump cover plate (pipe entry into Sump B, recirculation sump pit).

The strainer modules and associated components are designed for a maximum allowable head loss of 10 ft of water at 4000 GPM. Head loss less than 10 ft and reduced flow rates (such as the recalculated 1870 GPM design basis flow through the strainer; see response to Questions 33 and 19.c) results in additional structural margin.

NRC Question 38 The third portion of item 3.k of the revised content guide for the GL 2004-02 supplemental responses requests that the licensees "Summarize the evaluations performed for dynamic effects such as pipe whip, jet impingement, and missile impacts associated with high-energy line breaks (as applicable)." Please provide a detailed summary along with any additional supporting information regarding the assessment that the strainer modules are not subject to the aforementioned dynamic effects.

Response

An evaluation was performed to verify that the recirculation strainer and debris interceptors would not be impacted by a LOCA jet. The recirculation strainer is located in the east side of the Containment basement, between 3' 2" feet thick concrete support walls and the outer Containment wall (see Enclosures D and E-2 for pictorials). There are no postulated pipe breaks between the support walls and the outer Containment wall where the strainer is located. Postulated pipe breaks on the west side of the interior basement walls, west of the strainer, were evaluated and determined not to cause jet impingement or pipe impact on the strainer or debris interceptors. The nearest lines evaluated included:

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 68 of 77 PIPING PIPE OUTSIDE COMMENTS DIAMETER (IN.)

RHR outlet from RCS 8 No impact. A postulated guillotine break Loop B hot leg at valve RHR-1 B would travel parallel to the RHR pipe axis and would not impinge on the debris interceptors (D.I.) or strainer. A jet from a longitudinal break would impact the inside of the east shield wall but not the D.I. or strainer.

Pressurizer surge line 10 No impact. This line is located inside the Loop B vaults and is one floor above the Containment basement (sump) elevation.

Accumulator injection 12 No impact. This line is located within the 1B (SI-22B to RCS) Loop B RCP vault and is located above the Containment basement (sump) elevation.

Safety Inject to RCS 6 No impact. This line is located within the cold leg (SI-13B to Loop B RCP vault and is located above RCS) the Containment basement (sump) elevation.

Charging line to cold 2 No impact. This line enters Loop B RCP leg (CVC-12 to RCS) vault from the north side of Containment, west of the strainer area. A postulated break in the Containment basement elevation would impinge on the RCP B support steel beams.

CVC letdown off the 2 No impact. This two inch line is located crossover leg 8' 6" above the 592' floor elevation. A guillotine break at valve RC-200B would result in a jet parallel to the pipe run and to the inside of the shield wall. A guillotine break at the tee upstream of RC-200B would result in a circular jet approximately 3' 6" radius which would not reach the D.I. or strainer.

RTD lines 1, 2 & 3 No impact. These lines are located within the Loop B vaults and are located above the Containment basement (sump) elevation.

Cold leg to pressurizer 2 &3 No impact. This line is located within the Loop B vaults and is located above the Containment basement (sump) elevation.

Low head safety 4 &6 No impact. These lines are located one injection (SI-304A(B) to elevation above the Containment sump Rx Vessel) elevation.

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 69 of 77 NRC Question 39 Figure 4 of the licensee's February 2008 supplemental response indicates that three debris interceptors were installed as part of Dominion Energy Kewaunee, Inc.'s GL 2004-02 resolution efforts. However, these components were not mentioned in Section 3.k of the supplemental response. Please provide additional information regarding the structural adequacy of these components including a description and summary of the structural analyses that were performed to demonstrate the ability of these components to maintain their structural integrity during a design basis accident.

Response

The debris interceptors, C8x18.75 channel, were structurally evaluated for consideration of drag and hydrostatic loads, deadweight and seismic loads, including the inertia effects of the hydrodynamic mass during a seismic event. There are no dynamic loads on the debris interceptors from a postulated pipe break (no jet impingement or pipe impact).

Water Level for 3" Strainer Submergence (El. 595-4-1/4") ,r Water Flow H

El. 592'-o" Debris Interceptor Sump Strainer The debris interceptors were evaluated for a minimum water level of 40.5 inches which bounds the minimum water level at the start of recirculation. Evaluation with minimum water level provides a more conservative drag load for the evaluation.

The debris interceptors were conservatively evaluated with a sump flow rate of 4000 gpm, however, the actual design basis flow rate through the strainer was subsequently calculated as 1870 gpm.

The three design load combinations for the debris interceptors' steel structure are:

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 70 of 77 Condition Load Combination Allowable Normal, DL + LL (Note 1) AISC allowable Operating Basis DL + LL + DBA + OBE AISC allowable Earthquake (OBE) (Note 2)

Design Basis Earthquake DL + LL + DBA + DBE 1.5 x AISC allowable but no (DBE) (Note 2) greater than 0.9Fv Notes:

1) By comparison of Normal Condition and OBE, and since each has the same allowable, OBE is the bounding combination and therefore, the Normal Condition was not evaluated.

2) Each load combination containing DBA and seismic is divided into two sub-combinations. One is when the water level reaches the total height of the debris interceptor on the upstream side of the barrier and has no fluid on the downstream side (this condition maximizes hydrostatic head). The other sub-combination is when the fluid level reaches a steady state head of 40.5 inches and the interceptor is completely submerged.

The following is a summary of lateral loads associated with each critical load combination.

Combined Loads Condition Hydrostatic Drag Dynamic Hydrodynamic OBE water 0.0 psf (top)

= 46.8 psf 2.0 psf 23.0 psf 38.20 psf 110.00 psf (bottom)

ORE dEpth water N/A 2.0 psf 23.0 psf 44.78 psf 69.78 psf depth = 40.5" DBE water 0.0 psf (top)

= 46.8 psf 2.0 psf 46.0 psf 76.40 psf 171.20 psf (bottom)

DBE DEpth water N/A 2.0 psf 46.0 psf 89.56 psf 137.56 psf depth = 40.5" Notes:

1) Dynamic and hydrodynamic loads for DBE are twice OBE loads

2) Hydrostatic pressure is conservatively treated as a uniform pressure with base pressure applied over the entire height of the debris interceptor

3) Sub-combinations OBE water depth = 9" and DBE water depth = 9" are bounding pressures within each combination DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 71 of 77 The debris interceptors were initially evaluated for use of C9x13.4 channel. Subsequent to the evaluation, C8x18.75 channel was selected based on material availability and the C8x18.75 channel was evaluated and found to be acceptable. The evaluation included structural adequacy of the channel material, structural posts, welds between the channel and base plate, base plate material, and expansion anchors.

I. Upstream Effects NRC Question 40 Please describe the size of the refueling cavity drain line, the minimum flow restriction in this line, and any line losses associated with the drain line. Please also describe the types and quantities of debris that could transport to the refueling cavity, and the basis for concluding that debris blockage or partial blockage will not occur at the cavity drain.

The evaluation should account for the potential for some types of debris to remain buoyant following a loss of coolant accident, transport toward the cavity drain due to surface currents, and potentially sink on top of the cavity drain as water gradually displaces the air trapped in the debris material's pores. Please quantify the holdup volume assumed for the refueling cavity in the Containment pool minimum water level calculation.

Response

Debris blockage of the refueling cavity drain line was determined to be not credible.

The refueling cavity drain is located at the lowest cavity elevation, 608' 0", at the north end of the cavity (see Enclosure M). The drain opening is eight inches in diameter, connected to a four inch diameter drain line. The refueling cavity drain line enters Containment Sump A, below the Containment basement floor (recirculation sump) elevation. Containment Sump A drains to the Sludge Interceptor Tank in the Auxiliary Building, however, this line is isolated upon a Containment isolation signal.

Containment Sump A, when filled, overflows onto the Containment basement floor (recirculation sump).

The refueling cavity drain is located directly under the fuel transfer lifting frame. The drain has a removable standpipe that is eight inches in diameter, six inches high and has a 1 inch x 1 inch grid recessed in the standpipe top. Installation of the standpipe is controlled by a plant procedure to ensure the standpipe is in place during plant operation. The standpipe prevents non-suspended debris in the refueling cavity from entering the drain.

The minimum Containment sump water level calculation for the start of recirculation (2006-01660, Rev. 1) credits a hold up volume in the refueling cavity equal to 8.25 inches water height in the lower canal, or 74.2 ft3 (555 gal.). This is the height of water held up by the presence of the standpipe (C10941, Rev. 1). Ultimately, the cavity will DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 72 of 77 drain to 6" water height when Containment Spray is ceased. Containment Spray duration is approximately 55 minutes. Clean water enters the cavity from Containment Spray (injection mode). Kewaunee does not credit the use of recirculation spray for the LOCA event.

For the limiting hot leg break in the RCS Loop B Steam Generator Vault, large debris is not postulated to exit the top of the Steam Generator or Reactor Coolant Pump vaults and land directly on top of the refueling cavity drain line standpipe.

o The vertical vault walls will direct uplifted debris vertically into Containment.

o The refueling cavity drain standpipe is located horizontally approximately 57 ft from the break location. The break location is recessed in the Steam Generator Vault at the 617' 10" elevation. The top of the Steam Generator Vault walls are at the 666' and 660' elevation. The operating floor elevation is 649'. The refueling cavity drain is located at 608' elevation.

o There are multiple obstructions between the RCS hot leg piping and the standpipe that would prevent large debris from reaching upper Containment or the refueling cavity standpipe. These obstructions could also stop or deflect the transport of small debris.

" Steel grate work platforms surround the Steam Generator at the 624' 1" elevation.

" Steel handrails and work platforms surround the Steam Generator above the 660' elevation vault wall tops (shown in Enclosure M).

" In the adjacent/adjoining Reactor Coolant Pump Vault, steel grate work platforms are located at the 620' 3" and 633' 2" elevations.

" Many other obstructions are located between the break location and the refueling cavity drain, such as but not limited to, permanent ladders, handrails, equipment, ventilation equipment, structural steel, reactor vessel internals lift rig, the refueling cavity bridge crane and the fuel assembly transfer equipment.

o A piece of debris would need to be at least 8 in. wide and planar, and transportable or land horizontally and directly over the standpipe to block the drain line, and maintain this position as the refueling cavity pool fills. There is no credible scenario for this type of debris, trajectory and behavior during pool fill. r o A crumpled piece of sheet metal, if one were to land in the cavity, would not land directly over the drain opening due to the fuel assembly lifting frame over the drain, would not transport towards the drain due to the DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 73 of 77 weight of the material, and would not seal a drain opening due to its shape.

o Any fibrous insulation entering the refueling cavity pool would not land directly over the drain opening due to the fuel assembly lifting frame over the drain, would not be of sufficient size and density to block an eight inch diameter opening, and would not transport to the drain opening due to the high temperature of the pool water and low transport velocity in the pool.

• • The Containment atmosphere will be at approximately 210 deg F.

The sprayed water into the refueling cavity and Containment structures will therefore be hot which will aid in sinking debris and prevent or eliminate air bubbles trapped with the debris. Small fibrous insulation debris that may have entered the refueling cavity would occur in the initial phase of the break blowdown which allows time to settle in the refueling cavity during the time the cavity fills to above the drain standpipe opening. NUREG/CR-6808, Section 5.2.1, states, "Fiberglass insulation readily absorbs water, particularly hot water, and sinks rapidly (...from 20 to 30 seconds in-120°F water)." The revised debris inventory described in Attachment 1 to this letter indicates fibrous debris size will be limited to Fines after the described insulation removal activities are complete.

• • Floating debris would likely consist of Fines and small debris such as coatings that would pass through the drain opening.

• o The transport velocity around the drain, greater than 17 in. from the drain centerline, is calculated to be less than 0.1 fps. Any debris that transports over the cavity ledge to the lower cavity falls into an area where the velocity is less than 0.1 fps. NUREG/CR-6808, Section 5.2.1, states, "Water velocities needed to initiate motion of sunken insulation are on the order of 0.2 ft/s for individual shreds, 0.5 to 0.7 ft/s for individual small pieces (up to 4 in. on a side), and 0.9 to 1.5 ft/s for individual large pieces (up to 2 ft on a side)."

Therefore, any debris that may enter the pool other than Fines will not transport down the standpipe drain.

In addition to the limiting debris generation RCS hot leg break, other breaks are considered:

o A break in the RCS Loop A piping (hot leg, cold leg, or intermediate leg) would not generate any fibrous insulation debris, with the exception of fibers contained in calcium silicate (Thermobestos) insulation on the steam generator blowdown DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 74 of 77 lines. The fibrous portion of calcium silicate insulation is limited to Fines. There is no TempMat or Okotherm insulation in the RCS Loop A vaults.

The refueling cavity drain standpipe is closer in proximity to the "A" Steam Generator Vault, however, similar to the RCS Loop B configuration, between the postulated RCS Loop A piping and the refueling cavity drain there are several steel grating work platforms, structural steel shapes, equipment, piping, ladders and handrails that will deflect, distort and limit the size of reflective metal debris exiting the top of the vault. Additionally, due to the drain pipe location being below the fuel assembly lifting frame, an 8 inch diameter planar piece landing directly on top of the drain pipe is not credible.

o A RCS Loop B cold leg or intermediate leg break, similar to the limiting hot leg break, would be at an elevation within the vault below several steel work platform grating elevations. A cold leg break would not generate any calcium silicate (Thermobestos) debris. The cold leg and intermediate leg are located between the TempMat and Okonite cable insulation materials and the refueling cavity drain, therefore, it is postulated that this debris would likely be blown in the opposite direction from the cavity drain location.

o The reactor vessel top head is insulated with reflective metal insulation. A non-isolable leak or break at this location will not produce large fibrous debris into the refueling cavity.

As noted above, 555 gallons of hold up water volume is assumed to exist in the refueling cavity at the initiation of recirculation when the Containment sump water level is at its lowest during the recirculation phase. 555 gallons equates to approximately 0.22 inch sump water level at that time (Containment elevation) during the sump fill. At the onset of recirculation, the minimum sump water level is calculated at 43.44 inches.

The strainer height is 37.25 inches, therefore, the sump water level is 6.19 inches above the strainer surface. The strainer is analyzed for a minimum submergence equal to two inches above the top of the strainer. Therefore, the refueling cavity holdup volume accuracy is not critical to strainer submerge, however, note that blockage of the refueling cavity drain and accumulation of additional holdup at this location is not postulated.

J. Downstream Effectslln-Vessel NRC Question 41 The NRC staff considers in-vessel downstream effects to not be fully addressed at Kewaunee as well as at other pressurized water reactors. The licensee's submittal refers to draft WCAP-16793-NP, "Evaluation of Long-Term Cooling Considering Particulate, Fibrous, and Chemical Debris in the Recirculating Fluid." The NRC staff has not issued a final safety evaluation (SE) for WCAP 16793-NP. The licensee may DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 75 of 77 demonstrate that in-vessel downstream effects issues are resolved for Kewaunee by showing that the licensee's plant conditions are bounded by the final WCAP-16793-NP and the corresponding final NRC staff SE, and by addressing the conditions and limitations in the final SE. The licensee may also resolve this item by demonstrating without reference to WCAP-16793 or the staff SE that in-vessel downstream effects have been addressed at Kewaunee. In any event, the licensee should report how it has addressed the in-vessel downstream effects issue within 90 days of issuance of the final NRC staff SE on WCAP-1 6793.

Response

Kewaunee will submit a response to this item following the issuance of the SE for WCAP-16793. The response will be submitted within 90 days of issuance of the final SE on WCAP-1 6793.

K. Chemical Effects NRC Question 42 Please identify and justify all plant-specific refinements made to the WCAP-16530-NP base chemical model predictions and indicate how much each refinement reduced the predicted amount of precipitate compared with the October 2006 analysis. For example, if silicate inhibition was credited, please provide justification. Please provide any relevant bench-top testing and analysis that support reduction of the Kewaunee-specific chemical precipitate loading. Discuss why the overall plant-specific chemical effects evaluation remains conservative when crediting reductions to the WCAP-1 530-NP base chemical model. Additional information concerning staff expectations for the use of plant-specific refinements to WCAP-16530 is available in Section 9 of the Chemical Effects Review Guidance available at ML080380214.

Response

No plant-specific refinements were made to the WCAP-16530-NP base chemical model predictions. No bench-top testing was performed. Chemical precipitate loading was not reduced.

NRC Question 43 The licensee's February 29, 2008 supplemental response states that the minimum pH range calculation assumes end of cycle, minimum boron concentration. Likewise, the maximum pH is based on beginning of cycle maximum boron concentration. The staff would expect the maximum boron concentration to result in the minimum sump pool pH and the minimum boron concentration to result in the maximum sump pool pH. Please explain the basis for the pH calculations with respect to boron concentration at the DRAFT April 23, 2010

Serial No.10-025 Attachment 2

• Page 76 of 77 beginning and end of cycle. Also, please explain if the volume and concentration of sodium hydroxide is adjusted during the operating cycle.

Response

The following table was provided in our February 29, 2008 response, as Table 3.0-1 in Section 3.0, Chemical Effects. The text description in the "Input" column for the Low pH Range and High pH Range was transposed in the February 29, 2008 response.

The table below shows the corrected information. The transposition in the February 29, 2008 letter was a typographical error and does not affect our chemical precipitation analysis.

We do not adjust the volume or concentration of sodium hydroxide in the caustic standpipe during the operating cycle.

START OF LOCA 1,000,000 SECONDS (0 SEC.) (11.5 DAYS) INPUT pH pH Maximum RWST and Accumulator Boron Low pH Range 4.66 7.5 Concentration; RCS at 1514 ppm boron (beginning of cycle)

Minimum RWST and High pH Range 5.13 7.8 Accumulator Boron Concentration; RCS at 0 ppm boron (end of cycle)

L. Licensing Basis NRC Question 44 Please describe any surveillance requirements applicable to the emergency core cooling recirculation strainer installed at Kewaunee to ensure that the strainer is not restricted by debris and that there is no evidence of structural distress or abnormal corrosion.

Response

There currently are no Technical Specification surveillance requirements for the Emergency Core Cooling recirculation sump strainer. However, Kewaunee is transitioning to Improved Technical Specifications (ITS). The ITS will include a new surveillance requirement for a visual inspection of the strainer and debris interceptors every 18 months. The ITS submittal was sent to NRC on August 24, 2009 (ADAMS Accession No. ML092440426).

DRAFT April 23, 2010

Serial No.10-025 Attachment 2 Page 77 of 77 The new surveillance will verify no debris restrictions and no structural distress. The requirement also includes visual inspection to ensure no abnormal corrosion, however, the strainer and debris interceptor components are constructed from stainless steel materials.

The new surveillance requirement has already been incorporated into plant procedures OP-KW-OSP-CCI-003, Cold Shutdown Containment Inspection, and OP-KW-OSP-CCI-002, Containment Inspection During Power Operation.

DRAFT April 23, 2010

Serial No.10-025 Docket 50-305 Attachment 3 Page 1 of 1 LIST OF ENCLOSURES Enclosure Description No. of Pages A (RAI 1) Analyzed LOCA Pipe Breaks for Debris Generation 4 A-1 (RAI 2) MSDS for Thermo-12 (Pg 1 of 5) 1 B (RAI 5/6/7/12) Photos of TempMat, Fiberglass, Thermobestos 3 C-1 (RAI 8) Latent Debris Calculation C11928, Revision 0 44 C-2 (RAI 8) Latent Debris Procedure CM-AA-CRS-101, Revision 2 11 D (RAI 9) Debris Interceptors Installed in the Plant 2 E-1 (RAI 13/15/16) ARL Presentation from 9/15/09 Teleconference with NRC 8 E-2 (RAI 13/15/16) ARL Presentation from 11/10/09 Teleconference with NRC 14 E-3 (RAI 14) Containment Layout Cut-Away View 3 F-1 (RAI F.19.a) Excerpt from Clean Strainer Head Loss Calculation 4 F-2 (RAI F.19.a) Excerpt from Total Head Loss Calculation 4 G (RAI F. 19.c.vi) Flume Design Layout and Photographs 4 H (RAI F.19.c.xv) Photos of Debris Addition During Large Scale Tests 5 I-1 (RAI 23 & F.19.c.xiv) Clean Strainer Head Loss Test Data 2 1-2 (RAI 23 & F.19.c.xiv) Test 3 Design Debris Load Head Loss Test Data 1 1-3 (RAI 23 & F.19.c.xiv) Test 9 Supplemental Debris Load Head Loss 1 Test Data 1-4 (RAI F.19.c.xiv) Photos of Flume Drain down 3 J (RAI F.19.c.xv) Chemical Concentration Worksheets 2 K (RAI 20/21/22) Vortex Calculation TDI-6008-07, Revision 6 33 L-1 (RAI 37) Photos and Excerpts from Strainer Module Structural 8 Evaluation L-2 (RAI 37) Photos and Excerpts from Strainer Piping Structural 6 Evaluation M (RAI 40) Refueling Cavity Drain Location 4

Serial No.10-025 Docket 50-305 ENCLOSURE A (RAI 1) ANALYZED LOCA PIPE BREAKS FOR DEBRIS GENERATION ANALYZED RCS COLD LEG BREAK - NOT LIMITING BREAK REACTOR COOLANT PUMP I\ STEAM PRESSURIZER GENERATOR BREAK S1 RCS COLD LEG ZOI=5.45D R=12'-6" Page 1 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE A (RAI 1) ANALYZED LOCA PIPE BREAKS FOR DEBRIS GENERATION I ANALYZED RCS INTERMEDIATE LEG BREAK - NOT LIMITING BREAK I REACTOR COOLANT PUMP STEAM GENERATOR BREAK S2 RCS CROSSOVER LEG ZOI = 5.45 D R = 14'-1" -

PRESSURIZER Page 2 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE A (RAI 1) ANALYZED LOCA PIPE BREAKS FOR DEBRIS GENERATION ANALYZED RCS HOT LEG BREAK -LIMITING BREAK REACTOR COOLANT PUMP BREAK S3 RCS HOT LEG ZOI = 5.45 D R = 13'-2" PRESSURIZER Page 3 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE A (RAI 1) ANALYZED LOCA PIPE BREAKS FOR DEBRIS GENERATION ANALYZED RCS HOT LEG BREAK -LIMITING BREAK N

N%

/

/

j

/

• 1 BREAK S3 RCS HOT LEG ZOI= 17D R = 41'-1" - - /

ZOI = 28.6D R = 69'- 1 1/" (not shown) /

/

4%

Page 4 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE A-i (RAI 2) FIBER COUNT FOR JM THERMO'-12 (PG 1 OF ONLY)ý FORTHERMOBESTOS COMPARISON ONLY Date: 8/31/200ý5; IVMSDS ID: 20501 Rev: 1.0.4 industrialIhnsulationGroup Replaces:10/ýý/2003

&A 6a~iielJbhna manviille jott venture' Material safety Datas heet Material Narm e::Calciumri Silicate Insulation Section 1- Chemical Productand Company Identification Product Name: Thermo.12e Gold Calcium'Silicate6Iisulatibn CAS# Mixture/None Assigned Generic Name: Insulation (CalciumrSilicate)

Formula: Mixture Chemical Name:; Synthetic Calcium Silicate Manufacturer information -

industriatl ns ulaibi6n'Gb roup 21'00'12ine Street Brunswick,, GA. 31520 Phonenumber for Health and Safety Information: 970.85&6211 (M-F, 7:00a~m. t0 4:00p.m., Mountain"Time)

Trade Name: Thermno-12, Gold Sectioný2 - Composition and Information on ingredientsIOSHA ACGIH NIOSH CAS:# Component Percent PEL TLV REL UNITS3 1344-95-2 Synthetic Calcium-Silicate '>93 ' 15(T) 5(R) 10 10(T) 5(R).. mg/M 3

51274-00A1 Iro*-based color ... 15(T) 5(R) 10 NE. mg'/M3 65997-17-3 Synthetic Vitreous Fiber 0- 2 15(T) 5(R) 5' 5, mg/M 3

9004-34-6 :Cellulose Fiber 0-2 15(T) 5(R) 10 "10(T) 5(R) mg/M 3

1344-09-8 So~lium,.Silicate, 0- 6 15(T) 5(R). 10 NE nig/M NE= NotEstablished A*cGIH TLVs 'are2003 Viauesý. OSHA PELsiare those ineffect on the date of.preparation of ths* MSDS. The listed PE~s, 1VLs and RELs ae'tim~e weighted average exposure limit~s.

Component Related Regulatory information

'This product may be regulated, have exposure limits orlother.information identified as-the following:

Nuisance particulates.

Section 3-- Hazards Identification Emergency Overvlew APPEARANCE AND ODOR:. Odorless, Yellow semi-ciicle or block insulation with coloring throughout asa visual marker to indicatethis isan asbestos-free product.

This product is'an article and-under normal conditions of use, this product,:is notexpected-to create any unusual emergencyhazards. However, cutting, sawing, or, abrading may increaseihe risk of pers5hnihexposuIre Inhalation of excessive amounts of dust created when fabricating, cutting, or other mnechanical alterationsof the product may cause temporary upper respiratory irritation and/or congestidn- remove affected i..dividualsto fresh.

air.

Skir* irritation may be-treated-by gently washing affected area with soap and warm water.

Eye irritationmay be treated by flushing eyes with large amounts of water. Ifirritation persists, contact a physician.

Prolonged contact with dust from this product may cause Dermatitis.

In the event of fire, use normal fire fighting procedures to prevent inhalation of smoke and gases.

IIG20501 1 of 5 Page 1 of 1

Serial No.10-025 Docket 50-305 ENCLOSURE B (RAI 5/6/7/12) PHOTOS OF TEMPMAT, FIBERGLASS, THERMOBESTOS TempMat Fines TempMat Smalls Page 1 of 3

Serial No.10-025 Docket 50-305 ENCLOSURE B (RAI 5/6/7/12) PHOTOS OF TEMPMAT, FIBERGLASS, THERMOBESTOS Owens Corning Fines Owens Corning Smalls Page 2 of 3

Serial No.10-025 Docket 50-305 ENCLOSURE B (RAI 5/6/7/12) PHOTOS OF TEMPMAT, FIBERGLASS, THERMOBESTOS Nukon (Latent) Fines Pulverized Calsil Powder Page 3 of 3

Serial No.10-025 Docket 50-305 ENCLOSURE C-1 (RAI 8) LATENT DEBRIS CALCULATION C11928, REVISION 0 CALCULATION ATTACHED

CALCULATION COVER SHEET AND REVIEW REPORT Calculation No. C.1 1928 Title of Calculation: Latent Debris Determination Rev. No. 0 Addendum Letter N/A Title of Addendum: N/A Safety Related Z Yes ED No (1) (2)

System(s) / System No(s):

ICS/23, S1/33, RHR/34 (3)

Oriinating Document:

CR347736 (4)

Supersedes: uperseded By:

Calculation No(s). N/A alculation No(s). N/A Addendum No(s). *ddendum No(s).

(5) (6)

Discipline:

F1 Engineering Mechanics/Structural Engineering (EM/SE) E I&C D] Chemistry/Radiation Protection (Chem/RP) [] Nuclear ED Computer 0 Mechanical Dl Electrical (7)

This Calculation has been reviewed and was accomplished by the following: Reviewers' Initials (8)

Z Verification (Independent Review) _,_ _

El Technical Review Preparer Reviewer Comments Discipline Printed Name Signature - ESP Qual Date (9)

Attached Required

[] [-IYes E.....[ ID No Mech Lana Rabas .. .. . .. _____ '<Y

[1 X 0Z Yes El No Mech Lori Christensen Eli EYes F-1No Eli _________

... El E Yes El No 50.59 Applicability, Form Attached R1 Yes 50.59 Screen Form Attached El Yes N No 50.59 Pre-Screen Form Attached N Yes El No 50.59 Evaluation Attached [] Yes 0 No A4pprover: Wisconsin PE Stamp (If Required)

Printed Name: uJM. -41V4,i4 4,g N/A Signature:

Date:

Effective Date:

(See Steps 6.4,4 and 6.4.5 if E ate) 7 e1CiV (10) (11)l Form GNP-04.03.04-1 Rev. 009 Page 25 of 29 E USE

TABLE OF CONTENTS AND REVISION CONTROL Calculation No. C1 1928 Revision No. 0 Addendum Letter N/A Section, Attachment, or Other Description Page #(s) Revision Calculation Cover Sheet and Review Report (Form GNP-04.03.04-1) NA NA Table of Contents and Revision Control (Form GNP-04.03.04-2) NA NA Calculation Verification Checklist (Form GNP-04.03.04-3) NA NA Calculation Verification Comment/Resolution (Form GNP-04.03.04-4) NA NA Impacted Documents / Alternate Plant Configurations (Form GNP-04.03.04-5) NA NA Applicable 50.59 Review Forms (Reference NAD-04.04) NA NA Section 1.0 - Purpose 1 0 Section 2.0 - Background 1 0 Section 3.0 - Inputs and Assumptions 1 0 Section 4.0 - Methodology and Acceptance Criteria 3 0 Section 5.0 - References 5 0 Section 6.0 - Calculation and Results 6 0 Section 7.0 - Conclusions and Recommendations 10 0 1.2 pgs. 0 8 pgs. 0 6 pgs. 0 4 I.

+/- I-4 I.

+ I.

I Form GNP-04.03.04-2 Rev. 20 Date: AUG 25 2009 Page 26 of 29 REFERENCE USE

CALCULATION VERIFICATION CHECKLIST Calculation # C11928 Revision 0 Verification Items YES NO N/A Purpose 0 Clear objective and problem statement El El 0 Affected SSC been identified El 0 Intended use of results been identified El Er 0 Any limitation of applicability El 11 0 Revision content been summarized ET El Appropriate 50.59 products completed El El Methodology

• Discussion of the method/approach and major steps Er' El

• Limitation of use of methodology identified El El IT El Acceptance Criteria El

• Clear definition of acceptance criteria El

• Exceptions clearly defined Rl El

• Sources of acceptance criteria clearly defined El Assumptions B" El

" Sufficient rationale to permit verification of assumption El

• Have unverified assumptions been identified as such El

" References provided for assumptions El Inputs El

• All applicable Design Inputs been identified Er- El

• Has source document for inputs been identified and verified to be appropriate for use K*El

• Computer data program SQA approval 0E 0 El ],

References

• Have all controlled plant input documents been identified El El

• If a procedure is cited, has the process owner been notified El E]

• Are references available from KPS records, or have they been attached El Calculation and Results

• Correct formula/method used to support the objective El El

• Formula variables (including units) clearly labeled and consistent with sources El 191,

• Computer program input/output been reviewed E]

• Reference to sketches provided El El El

• Sufficient bases/rational to permit verification of engineering judgment El El

• Proper carry over and use of significant digits El El El

• Computations reasonable, correct. Ell El El El Conclusions and Recommendations

" Clear statement of the results consistent with the objective El El

• Acceptability of the results clearly defined El

• Recommendation for unacceptable results, CR written if necessary El El El

• Clear definition of limitations or requirements imposed by the calculation necessary to maintain the validity of the results

• Have the effects of the calculation on output documents been identified and addressed HagEl El Form GNP-04.03.04-3 Rev. 20 Date: AUG 25 2009 Page 27 of 29 REFERENCE USE

CALCULATION VERIFICATION COMMENT/RESOLUTION Calculation # C11928 Revision 0 Reference Material Used: GNP-04.03.04 and Cl 1928 references Reviewer's Comment Preparer Resolution Reviewer Item # Concurrence 5.2.1 - The cited reference is not retrievable Cited a different probability and ....

(unless purchased). Cite a new reference statistic book that I have available.

that is readily available.

Additional impacted documents include:

51-9020502, Rev. 3, including Addendum Documents added on Form GNP-2 A, CN-CSA-05-78, Rev. 1, including 04.03.04-5 and GNP-05.27.07-1. L_

Addendum A, and CN-CSA-05-79, Rev. 1.

Latent debris total quantity acceptance criteria shall be listed in 4.2, else make Provided in 4.2. Revised 7.0 reference to plant procedures where the accordingly.

acceptance criteria currently resides.

Add additional references: 51-9020502, Rev. 3, sample and evaluation procedures Included references.

(NEP-04.22, NEP-04.23, CM-AA-CRS-101), and P&S Activity RE304731.

Table 6-2 and Attachment 2, corrections 5 noted for cable trays 1CL7S5, 1CT106N, Corrected values.

1CT107N, ICT108N and 1CX112N.

Attachment 3, revise mass and area values 6 for horizontal equipment surfaces (pg 5 of Revised values.

6).

Incorporate changes to Sections 4 and 7 to 7 allow deletion of NEP-04.22 and NEP- Incorporated changes.

04.23.

Comment cycle complete:

Preparer: Lana Rabas ,... -, . Date: i;/J i -. t Print S' nature - ESP Qual Required Reviewer: Lori Christensen 16Date0/-, Date-, /,2 Print "'S gnature - ESP Qual Required Form GNP-04.03,04-4 Rev. 20 Date: AUG 25 2009 Page 28 of 29 REFERENCE USE

KEWAUNEE IMPACTED CALCULATION DOCUMENTS / ALTERNATE PLANT PROCESS CONFIGURATIONS NOTE: Refer to GNP-04.03.04, Step 6.2.12 or Step 6.5.5 for Form Instructions.

Calculation Number: C 11928 Rev.: 0

Title:

Latent Debris Determination Responsible Condition Report or Document or APC Document or APC Individual or Revisions Corrective Action Number Description or Title Process Owner Required Number(s) 32-9071852, Kewaunee Power Station - L Christensen Yes CR 360908 Rev. 0 Debris Transport WPS-06-36, Rev Downstream Effects Evaluation L Christensen Yes CR 360908 0 including Add. To Support The Resolution Of A GSI-191 For Kewaunee Update Nuclear Fuel and Reactor Vessel Analysis To Reflect WCAP-16406-P Revision 1 And Debris Load Changes TDBD-KPS- Generic Safety Issue - 191 L Christensen Yes CR 360908 GSI-191, Rev. 2 Assessment of Debris Accumulation on PWR Sump Performance, Kewaunee 2004-08820, GSI-191 Debris Generation L Christensen Yes CR 360908 Rev. 3 Calculation 51-9020502, Chemical Precipitation Analysis L Christensen Yes CR 360908 Rev. 3 For Kewaunee Power Station Using WCAP-16530-NP CN-CSA-05-78, GSI-191 Downstream Effects for L Christensen Yes CR 360908 Rev. 1 including Kewaunee Debris Ingestion Add. A Evaluation CN-CSA-05-79, Kewaunee GSI-191 Downstream L Christensen Yes CR 360908 Rev. 1 Effects Debris Fuel Evaluation 51-9020502, Chemical Precipitation Analysis L Rabas Yes CR 360908 Rev. 3 Add. A For Kewaunee Power Station Using WCAP-1 6530-NP Maximum Allowable Aluminum Content Evaluation C 11828, Rev. 0 Kewaunee Post-LOCA L Christensen Yes CR 360908

.... _ Particulate Deposition on Fuel Form GNP-04.03.04-5 Rev. 20 Date: AUG 25 2009 Page 29 of 29 REFERENCE USE

50.59 APPLICABILITY REVIEW (Is the activity excluded from 50.59 review?)

1. Document/Activity number: Calculation CI 1928, Rev. 0

2. Brief description of proposed activity (what is being changed and why):

This calculation determines the total latent debris in Containment based on sample measurments and Containment surface areas Does the proposed activity involve or change any of the following documents or processes? Check YES or NO for EACH applicability review item.

Explain in comments if necessary. [Ref. USA 50.59 Resource Manual]

NOTE: If you are unsure if a document or process may be affected, contact the process owner.

Yes No Document or Applicable Contact/Action S V" Process Regulation Process change per LI-AA-l 01.

Technical Specifications or Operating License IOCFR50.92 Coct cesng.

a E] N Contact Licensing.

Identify NRC letter in conmnents below. Process b [] Activity/change previously approved by NRC in IOCFR50.90 change.

license amendment or NRC SER Contact Licensing for assistance.

Activity/change covered by an existing approved I OCFR50 Appendix B Identify screening or evaluation in comments below.

IOCFR50.59 review, screening, or evaluation. Process change.

0 10CFR50.54(a) Contact QA.

d El Dominion Quality Assurance Program Description (DOM-QA-1) Refer to NO-AA-! 01.

Contact EP, e Emergency Plan 10CFR50.54(q) Refer to FP-R-EP-02.

f [Security Plan 10CFR50.54(p) Contact Security.

Refer to FP-S-SPE-01.

0l 1Z IST Plan 10CFR50.55a(f) Contact IST process owner.

g I I Refer to ER-AA-IST-10.

h1 El z Ih_________SIPlan_10CFR50.55ag)_ER-AA-NDE-122, ISI Plan ICFR5.55a(g) Contact ISI process owner. Refer to NAD-01.05, and NAD-05.1 1.

I F-1 ECCS Acceptance Criteria 10CFR50.46 Contact Licensing.

USAR or any document incorporated by reference - Process USAR change per NEP-05,02.

j Check YES only if change is editorial (see IOCFR50.71 Contact USAR process owner forassistance.

Attachment A).

Commitment - Commitment changes associated Contact Licensing.

k E [a with a response to Generic Letters and Bulletins, or IOCFR50 Appendix B Refer to LI-AA-1 10.

if described in the USAR require a pre-screening.

Maintenance activity or new/revised maintenance Evaluate under Maintenance Rule.

El 0 procedure - Check YES only if clearly maintenance and equipment will be restored to its as-designed IOCFR50.65 Refer to ER-AA-MRL- 10, ER-AA-MRL- 100, and NAD-08.21.

condition within 90 days (see Attachment C).

New/revised administrative or managerial directive/procedure (eg., NAD, GNP, Fleet SE contr a change t anyt rocedure)document other procedrawing)r which IOCFR50 Appendix B Process procedure/document revision.

clearly editorial/administrative. See Attachments A and B.

o El S Fire Plan I 0CFR50.48 Fire Protection Program Document Change Control, GNP-05.30.01.

0o El Independent Spent Fuel Storage Installation (ISFSI) I OCFR72.48 Implement DNAP-3004, starting with Applicability.

4. Conclusion. Check one of the following:

All documents/processes listed above are checked NO. IOCFR50.59 applies to the proposed activity. A 50.59 pre-screening shall be perfonned.

F- One or more of the documents/processes listed above are checked YES, AND controls all aspects of the proposed activity. IOCFR50.59 does NOT apply. Process the change tunder the applicable program/process/procedure.

FE One or more of the documents/processes listed above are checked YES, however, some portion of the proposed activity is not controlled by any of the above processes. 10CFR50.59 applies to that portion. A 50.59 pre-screening shall be performed.

5. Coimnents:

None

6. Print name followed by signature. Attach completed fonn to docunent/activity/change package.

Prenared by: Lana Rabas / Date: , aiŽ J 1'-/(_,

(print/sign)

Date: 2 10 Reviewed by: Lori Christensen (print/sign)

Form GNP-04.04.01-1 Rev. 12 Date: APR 08 2008 Page 15 of 16 INFORMATION USE

50.59 PRE-SCREENING (Is a 50.59 screening required?)

1. Document/Activity number: Calculation Cl 1928, Rev. 0

2. Brief description of proposed activity (what is being changed and why):

This calculation detennines the total latent debris in Containment based on sample measurements and Containment surface areas.

3. Does the proposed activity involve or change any of the following documents or processes? Explain in Comments if necessary.

Check YES or NO for EACH pre-screening item. [Ref. USA 50.59 Resource Manual]

NOTE: If you are unsure if a document or process may be affected, contact the process owner.

NOTE: An asterisk (*) indicates that the document is incorporated by reference in the USAR or is implicitly considered part of the USAR.

NOTE: Check NO if activity/change is considered editorial, administrative, or maintenance as defined in Attachments A, B, and C. Explain in Comments if necessary.

Document/Process Directive/

Yes -/ No" Procedure a F ] Updated Safety Analysis Report (USAR) NEP-05.02 b []

Zi

• Technical Specifications Bases or Technical Requirements Manual (TRM) LI-AA-IO1, LI-AA-101-1001 c [] [

• Commitments made in response to NRC Generic Letters and Bulletins, and those described in the USAR LI-AA-110 d E] M

• Environmental Qualification (EQ) Plan NAD-01.08 e

• Regulatory Guide 1.97 (RG 1.97) Accident Monitoring Instrumentation Plan NAD-05.22 f F1 Z

• Fire Plan NAD-01.02 g LI [

• Appendix R Design Description NAD-01.02 h N] - Fire Protection Program Analysis (FPPA) NAD-01.02 i EJ Z

• Offsite Dose Calculation Manual (ODCM) NAD-05.13 j Z

• Radiological Environmental Monitoring Manual (REMM) NAD-05.13 k E] Z

• Station Blackout Design Description 1

• Control Room Habitability Study Plant Drawing Changes/Discrepancies-Check YES only if: I) the change adds information to, deletes information from, or alters the configuration of a drawing that is incorpomted in the USAR, or 2) configures an SSC NAD-05.01 differently than described or credited in USAR text.

Calculations/Evaluations/Analyses/Computer Software - Check YES only if: 1) It affects a method of evaluation Various described in the USAR, or 2) It independently (i.e., not part of a modification) affects the licensing or design basis.

o [Zl Permanent Plant Physical Changes - All require a screening. NAD-04.03 P El E] Temporary Plant Physical Changes (TCRs) - Check No only if installed for maintenance AND in effect for less NAD-04.03 than 90 days at power conditions.

QA Typing Determinations - Check YES only if reduction in classification, or affects design function as described NAD-01.01 q LI [] in USAR.

r E] N Setpoint or Acceptance Criteria - Check YES only if change affects plant monitoring, perfommance, or operation. Various LI ~ Plant Procedures/Revisions - Check YES only if the change directly or indirectly involves operating, controlling NAD-03.0I or configuring an SSC differently than described or credited in USAR.

t Engineering Specifications - Check YES only if a design function or design requirement may be affected. NAD-05.03 o Operations Night Orders or Operator Work Arounds - Check YES only if SSCs are operated or configured GNP-03.30.01 differently tian described in USAR.

NAD-08.14, Temporary plant alterations (e.g., jumpers, scaffolding, shielding, barriers) - Check YES only if installed (or in GMP- 127, v El z effect) for maintenance for longer than 90 days at power conditions. GNP-01.23.04, FPP-08-09

- [Temporary plant alterations - Check YES only if not associated with maintenance.

x D Conrective/Compensatory Actions - Check YES only if degraded/non-conforming plant condition accepted "as-is" OP-AA-102 xorcompensatory action taken, 4 Conclusion. Check one of the following:

All of the documents or processes listed above are checked NO, A 50.59 screening is NOT required. Process change in accordance with the applicable program/process/procedure.

LI One or more of the documents or processes listed above are checked YES. A 50.59 screening shall be perforned.

5 Comments:

Item n: This calculation does not affect a method of evaluation. It does not independently affects the licensing or design basis as the latent quantity remain below the analyzed quantity.

6 Print name followed by signature. Either the preparer or reviewer shall be 50.59 screening qualified. Attach completed form to document/activity/change package. . -......

Prepared by: Lana Rabas /A1--- K /' . Date: k(JJ*.;(,..i (print/sign) /I/-D Reviewed by: Lori Christensen /: * .//.7/;_______._Date:_____

t/ e.....

7 Form GNP-04.04.01-2 Rev. 12 Date: APR 08 2008 Page 16 of 16 INFORMATION USE

KEWAUNEE NUCLEAR POWER PLANT DESIGN BASIS DATABASE LOAD FORM DOCUMENT INFORMATION 6.2.1.1 Document Type Calculation / Evaluation 6.2.1.2 Document ID C11928 6.2.1.3 Document Title Latent Debris Determination 6.2.1.4 KPS Revision 0 6.2.1.5 Addendum N/A 6.2.1.6 Document Date 6.2.1.7 Topic This calculation determines the total latent debris (dirt, dust) in Containment based on sample measurements and Containment surface areas.

6.2.1.8 Document Status Current 6.2.1.9 Superceded By N/A 6.2.1.10 Attachments Y 6.2.1.11 Safety Related Y AUTHOR INFORMATION 6.2.2.1 Author/Submitter Lana Rabas 6.2.2.2 Vendor N/A 6.2.2.3 Vendor Author N/A 6.2.2.4 Discipline Mechanical DOCUMENT RELATIONSHIPS 6.2.3.1 System(s) 023,033,034 6.2.3.2 DCR(s) N/A 6.2.3.3 Keyword(s) CALC INDEX GSI-191, Strainer, LOCA 6.2.3.4 Inputs 2004-08820 Rev. 3, N-I4,* -ve.7 , CM-AA-CRS-101 6.2.3.5 Outputs 32-9071852 Rev. 0, WPS-06-36 Rev. 0 & Add. A, TDBD-KPS-GSI-191 Rev. 2, 51-9020502 Rev. 3 & Add. A, CN-CSA-05-78 Rev. 1 &

Add. A, CN-CSA-05-79 Rev. 1, C11828 Rev. 0 ADMIN/RECORDS USE ONLY 6.2.4.1 Comments 6.2.4.2 Record Type 6.2.4.3 Retention Period 6.2.4.4 Software Application 6.2.4.5 Vault Location 6.2.4.6 Film Reel 6.2.4.7 Reel Odometer" Form GNP-05.27.07-1 Rev. 9 Date: MAR 20 2008 Page 11 of 11 INFORMATION USE

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination 1.0 PURPOSE This calculation determines the total quantity of latent debris (dirt, dust) in Containment. The quantity is determined by debris samples collected by CM-AA-CRS-101, Latent Debris Collection and Sampling Procedure (Reference 5.2.14).

Latent debris is part of the Post-LOCA (Loss of Coolant Accident) generated debris inventory. This debris inventory is an input to the debris transport calculation (Reference 5.2.9). The transport calculation determines the quantity of post-LOCA debris that has the potential to reach the Containment recirculation sump strainer (158-051) and affect the head loss for the strainer (Reference 5.2.11). The transported debris can also affect the quantity of debris that can bypass (flow through) the strainer and impact the amount of wear on downstream components due to operating with debris-laden fluid, as well as potentially impact the debris bed formed on the nuclear fuel support grids (Reference 5.2.8 and 5.2.10). Latent debris is also an input to the post-LOCA chemical precipitation analysis (Reference 5.2.13).

2.0 BACKGROUND

This calculation supersedes Attachment 8.12 of Calculation 2004-08820, Rev. 3, "GSI-191 Debris Generation." During a review of the latent debris sampling and statistical analysis evaluation it was noted that several surface areas were omitted from the original calculation that should have been included (Reference 5.2.12). This calculation is updated to include the new surfaces and re-evaluates the overall quantity of latent debris in Containment with the additional surfaces.

3.0 INPUTS AND ASSUMPTIONS 3.1 INPUTS 3.1.1 Sample Data Table 3-1: Sample Data Debris Area Loading Sample (g) Area (ft2) (g/ft2) Surface Direction Elevation 12 0.7 11'0" x 3'0" 33.0 0.021 Clean Floor Horiz 649' 13 0.15 7'0" x 8'0" 56.0 0.003 Clean Floor Horiz 592' 4 1.8 3'6"x 5'6" / 2 9.625 0.187 Dirty Floor Horiz 592' 5 -0.1 4'4" x 5'2" 22.4 0.000 Clean Wall Vert 606' 7 0.1 5'9" x 9'0" 51.8 0.002 Clean Wall Vert 626' 9 0.3 4'0" x 18'0" 72.0 0.004 Clean Wall Vert 626' 6 0.3 Various 3.4 0.088 Dirty Horizontal Horiz 606' 8 0.8 2'6" x 4'0" 10.0 0.080 Dirty Equipment Horiz 626' 14 0.4 1'4" x 5'8" 7.6 0.053 Dirty Ductwork Horiz 592' 11 0.1 30" x 4'0" x 3 36.0 0.003 Dirty Ductwork Vert 649' 10 0.5 4'6" x 7'9" 34.9 0.014 Dirty Wall Vert 649' 15 2.0 5'0" x 910" 45.0 0.044 Dirty Wall Vert 592' Page 1 of 10

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination See Attachment I for sample collection data sheets.

The initial debris sample collections were performed by Sargent & Lundy during the 2004 refueling outage.

Samples 1, 2, and 3 were preliminary samples and the results were skewed; therefore, these were not included.

3.1.2 t - Distribution Values The upper-tailed t-distribution values provided are at the 90% confidence level (Q = 1 - 0.9 = 0.1), where the degrees of freedom (v) is the number of samples minus 1 (Ref. 5.2.1) [partial table below].

t = 1 .886 cy for 3 samples t = 3.078 (Yfor 2 samples Table 3-2: Upper-Tailed t-Distribution Values v/Q 0.15 (85%) 0.10 (90%) 0.05 (95%) 0.025 (97.5%)

1 1.963 3.078 6.314 12.706 2 1.386 1.886 2.290 4.303 3 1.250 1.638 2.353 3.182 4 1.190 1.533 2.132 2.776 5 1.156 1.476 2.015 2.571 6 1.134 1.440 1.943 2.447 7 1.119 1.415 1.895 2.365 8 1.108 1.397 1.860 2.306 9 1.100 1.383 1.833 2.262 3.2 ASSUMPTIONS 3.2.1 It is assumed that the debris is normally distributed for a given surface type. This assumption is supported by walkdown observations that debris distribution appeared uniform for a given surface type.

3.2.2 It is assumed that the debris loading on cable trays is the same as the loading on ventilation ductwork. Debris samples are not collected from cable trays (Reference 5.2.14).

Page 2 of 10

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination 3.2.3 It is assumed that debris loading for a given surface or surface type, when not available due to lack of sample data, is the same as debris loading for a similar surface type. The assumptions will be documented in Table 6-2.

4.0 METHODOLOGY AND ACCEPTANCE CRITERIA 4.1 METHODOLOGY 4.1.1 Data collection is performed in accordance with procedure CM-AA-CRS-101, Latent Debris Collection and Sampling Procedure (Reference 5.2.14).

4.1.1.1 Using Table 6-2, determine the locations for sample collection.

4.1.1.2 Obtain at least 24 usable samples, with samples from each of the surface types.

4.1.1.3 Determine if the new sample data will supersede the previous samples, or if the new sample data will be added to the existing data.

Consideration should be given to cleaning activities that many have occurred since the previous samples were obtained.

4.1.2 The Containment surfaces used to determine the total post-LOCA latent debris (dirt, dust) loading that can potentially reach the Containment sump recirculation strainer are listed in Table 6-2.

4.1.2.1 The surface area calculations are included as Attachment 2.

4.1.3 For each surface or surface type, dependent on sample availability, determine the sample mean and sample standard deviation.

5c E X-i (Eq. 4-1) n-1 S (Eq. 4-2)

Where: * = mean for group of samples (g/ft2 )

X= individual sample mass per area (g/ft2) n= number of samples in group s= sample standard deviation (g/ft2) 4.1.4 Assuming the debris is normally distributed and the number of samples is small relative to the total population, determine an upper limit on the mean debris loading from the t-distribution at 90% confidence.

-tuL- < A < x+ tuLS Page 3 of 10

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination 5 + tU s (Eq. 4-3)

Where: tUL = t distribution value at 90% confidence for sample size n AUL = upper limit on the mean debris loading at 90%

confidence (g/ft2 )

4.1.5 Estimate the total debris mass for each surface and surface type by multiplying the total area for the surface type by the upper limit on the mean debris loading at 90% confidence (g/ft2).

4.1.6 When data is not available for a given surface, substitute a debris loading from a similar surface type until future data is available. Document the substitution as a calculation assumption in Table 6-2.

4.1.7 When the acceptance criteria administrative limit is exceeded, or is being approached, initiate a Condition Report (CR) to evaluate Containment cleanliness and determine if corrective actions are necessary.

4.2 ACCEPTANCE CRITERIA 4.2.1 The acceptance criteria for the total allowable quantity of latent debris in Containment is determined by the quantity of latent debris assumed in the GSI-191 tests and analyses.

4.2.1.1 The acceptable quantity of latent debris for the entire Containment Building is 100 lbs.

4.2.1.2 Fifteen (15) percent of the latent debris is assumed to be fibrous debris.

4.2.1.2.1 The acceptance criteria for latent fibrous debris is 15 lbs.

4.2.1.2.2 The administrative limit for latent fibrous debris is 10 lbs.

4.2.1.3 Eighty-five (85) percent of the latent debris is assumed to be particulate debris.

4.2.1.3.1 The acceptance criteria for latent particulate debris is 85 lbs.

4.2.1.3.2 The administrative limit for latent particulate debris is 60 lbs.

Page 4 of 10

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination

5.0 REFERENCES

5.1 DRAWINGS 5.1.1 S-220, Revision J, Reactor Building Containment Vessel 5.1.2 S-221, Revision U, Reactor Building Containment Vessel 5.1.3 S-235, Revision 0, Reactor Building Concrete Basement Floor El. 592'-0".

5.1.4 S-237, Revision 0, Reactor Building Concrete Sections & Details.

5.1.5 5-239, Revision Y, Reactor Building Concrete Mezzanine Floor El. 606'-0".

5.1.6 S-246, Revision BC, Reactor Building Concrete Floor Plan at El. 626'-0".

5.1.7 S-258, Revision V, Reactor Building General Section -Concrete Reinforcing.

5.1.8 S-263, Revision H, Reactor Building Unit 1 Reactor Shield Liner 5.1.9 S-250, Revision AB, Reactor Building Concrete Floor Plan at El. 649'-6'.

5.1.10 S-272, Revision S, Reactor Building Wall Reinforcing - Elevation & Details.

5.1.11 S-273, Revision T, Reactor Building Wall Reinforcing - Elevation & Details.

5.1.12 E-314, Revision E, Cable Tray & Conduit System Reactor Bldg. Partial Plans El.

606'-0" Sh. 1.

5.1.13 E-315, Revision H, Cable Tray & Conduit System Reactor Bldg. Partial Plans El.

606'-0" Sh. 2.

5.1.14 E-316, Revision J, Cable Tray & Conduit System Reactor Bldg. Plan El. 592-0" 5.1.15 E-317, Revision Q, Cable Tray & Conduit System Reactor Bldg. Plan El. 606'-0".

5.1.16 E-318, Revision N, Cable Tray & Conduit System Reactor Bldg. Plan El. 626'-0".

5.1.17 M-365, Revision AK, Reactor Bldg. Piping-Chem & Vol. Control, Sample, Reactor Coolant, Waste Disposal 5.1.18 M-684, Revision D, Ventilation Reactor Building Dome.

5.1.19 M-685, Revision F, Ventilation Reactor Building El. 649'-8".

5.1.20 M-686, Revision N, Ventilation Reactor Building El. 626'-0".

5.1.21 M-690, Revision C, Ventilation - Reactor Building CRDM Cooling.

5.1.22 M-693, Revision D, Ventilation Reactor Building Elevations.

5.1.23 M-694, Revision C, Ventilation - Reactor Bldg. Sections.

5.1.24 M-695, Revision E, Ventilation Reactor Building - Sections.

5.1.25 M-696, Revision D, Ventilation Reactor Building Sections.

5.1.26 XK-100-1, Revision 17A, Steam Generator, 51 Series -Outline Sh. 1 and 2 5.1.27 XK-100-161, Revision 5, Pressurizer Relief Tank 5.1.28 XK-106-27, Revision 0, Crane Girder 5.1.29 XK-126-1, Revision 4A, General Arrgt of 2 Bridges Plan & Elevation 5.1.30 XK-126-5, Revision 5A, General Arrgt 3 Motor Trolley - Plan View 5.1.31 XK-126-6, Revision 2, General Arrgt 3 Motor Trolley - Elevations 5.1.32 XK-310-19, Revision C, Pump, Coolant - Insulation Arrangement 5.1.33 XK-310-22, Revision A, Pump, Coolant - Insulation Top & Bottom Head Page 5 of 10

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination 5.2 OTHER DOCUMENTS 5.2.1 Walpole, Ronald E., et al. Probability & Statistics for Engineers & Scientists. 7 th Edition. Upper Saddle River, NJ: Prentice-Hall Inc., 2002 5.2.2 Safety Evaluation by the Office of Nuclear Reactor Regulation Related to NRC Generic Letter 2004-02, Nuclear Energy Institute Guidance Report (Proposed Document Number NEI 04-07), "Pressurized Water Reactor Sump Performance Evaluation Methodology," Draft Issued September 20, 2004.

5.2.3 Calculation 2006-01660, Revision 1, Post LOCA Containment Flood Level (DCR 3605).

5.2.4 Vendor Technical Manual ALLIE-0004, Revision 0, Telescoping Boom Crane Model TB24-65.

5.2.5 Kewaunee Power Station Updated Safety Analysis Report (USAR), Section 6.2.2 and Table 6.2-13, Revision 21.4 - Updated Online 09/30/09.

512.6 Kewaunee Cable Raceway Application, Version 1.0.0, Run Date: 10/28/09.

5.2.7 Calculation 2004-08820, Revision 3, GSI-191 Debris Generation 5.2.8 Calculation 51-9017897, Revision 2, Kewaunee RHR, SI and ICS Pump Evaluation for GSI-191 Downstream Effects 5.2.9 Calculation 32-9071852, Revision 0 including Add. A, Kewaunee Power Station -

Debris Transport 5.2.10 Calculation WPS-06-36, Revision 0 including Add. A, Downstream Effects Evaluation To Support The Resolution Of GSI-191 For Kewaunee 5.2.11 Calculation TDI-6008-06, Revision 8, Total Head Loss (ECCS Recirculation Strainer) - Kewaunee Power Station 5.2.12 CR347736, GSI-191 Latent Debris Calculation, 9/9/2009.

5.2.13 Calculation 51-9020502, Revision 3, Chemical Precipitation Analysis For Kewaunee Power Station Using WCAP-16530-NP 5.2.14 CM-AA-CRS-101, Revision 1, Latent Debris Collection and Sampling Procedure 5.2.15 Planning and Scheduling Activity RE304731, Latent Debris Collection 5.2.16 TDBD-KPS-GSI-191, Revision 2, Generic Safety Issue - 191 Assessment of Debris Accumulation on PWR Sump Performance, Kewaunee.

6.0 CALCULATION AND RESULTS 6.1 Sample data collection results are included as Attachment 1.

6.2 The surface area evaluations are included as Attachment 2 and the results are presented in Table 6-2.

Page 6 of 10

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination 6.3 Using the t-distribution values from Input 3.1.2, the mean debris loading at 90% confidence was determined for each surface type or specific surface listed in Table 6-2. Refer to Attachment 3 for the mean debris loading evaluation.

6.3.1 The results of the evaluation are summarized in Table 6-1 and are based on sample data available to date.

Table 6-1: Debris Loading Results SURFACE TYPE SAMPLE NUMBERS DEBRIS LOADING 2

(gift )

Floors and Horizontal Structures 4, 12, 13 0.181 Containment Liner 7, 9 (sample 5 omitted) 0.006 Walls 10, 15 0.076 Vertical Ventilation/Ductwork 11 0.003 Horizontal Ventilation/Ductwork 14 0.058 Cable Trays Not sampled (use horizontal 0.058 vent/duct data)

Horizontal Equipment Surfaces 6, 8 0.097 Vertical Equipment Surfaces Not available (use wall data) 0.076 6.4 The total debris mass for each surface type and specific surface are listed in Table 6-2.

Page 7 of 10

Dominion Energy Kewaunee Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Table 6-2: Latent Debris Evaluation and Results SURFACE AREA DEBRIS LOADING DEBRIS TOTAL DEBRIS TOTAL ASSUMPTIONS/NOTES 2

SURFACE TYPE (ft ) ~(qift ) 2 (g) (Ibm) __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Floors and Horiontal Structures 649'-6" Floor Elevation 4,670.995 0.181 845.450 1.864 626'-0" Floor Elevation 2,478.400 0.181 448.590 0.989 606'-0" Floor Elevation 5,758.569 0.181 1,042.301 2.298 592'-0".." Floor.. ... Elevation

-. .................. .3 8,145.001 3 0.181 2...........................

-.6 ..............

.... 1,474.245 3.250 w s --

666'-0" Pressurizer Missile Shield 36260.181 _ 55.445 0.122 Includes top of vault walls at this location 655'-6" Elevation RCP A/B Vault Wall Tops 257.971 0.181 46.693 0.103 660'-0. Elevation SG NB Vault Wall Tops 483. 906 0.181 87.587 0.193 Refueling Cavity Pool Floor (Elevations 623'-7", 1,021.754 0.181 184.937 0.408 " per vault 613'-6', & 608'.......-0 ----. 813 2 24.6 8Include s two slabs at elevation in609'-1 B vault 609'- l" 17 4 440 .... --------------

088Slab on elevation 616*-0" only SG AiB Vault Floors (Elevations 605'-4", 17444.113224 and 616'-0")

,48.0000.11 48.80 0990Surface area per USAR Table 5.8-1 (assume Floo/Stir ratng Subject to Containment Spray 41,239.087 0.006 247.435 0.545 606'-0" elevation and above Basement Elevation 4,618.141 0.006 27.709 0.061 592'-0" elevation ........ ........... ....

........ 2 ........... ........................ _... ........... ........

~  ? 0* £ * ..........

Waits.

W au...t.....G

..... ~ ns£c...  !*

p~........ ............ ......................... ................12,902.052

.~~. . .

SG and RCP Vault Walls 0.076 980.556 2.162 Pressurizer Exterior Vault Walls 835,339 0.076 63.486 0.140 Interior walls protected from spray and break jet PeuzEtiVatas33006384 by missile shield and floors within vaults Refueling Cavity Pool Walls 5,033.580 0.076 382.552 0.843 Walls likely cleaner due to pool flood/drain Due to 0.064 Due to only one sample available, 10% 10% is is added added Horizontal 649'-6" Elevation and Above 1,833.057 0.058 29.111 s fr __a fdior mar..................

Verticatlo 698nEeaio n/boe0031u2 499.323 0.058 106.867 0.236 t .loeadings the d 008Dutolonsmleviale 0 i de Horizontal CRDM and 626'-0" Elevation added is ---------

---

t-Due todeonly the---- ri one lo disampleg---ar~ available, 10% --------

............................... 12,828 0.028 3,887,397 0.003 Vertical 649'-6" Elevation and Above 2.573 0.006 Det nyoesml vial,1%i de 779.804 0.003 Vertical CRDM and 626'-0" Elevation to the debris Ioadinp for mar~gin Page 8 of 10

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Table 6-2: Latent Debris Evaluation and Results (cont.)

SURFACE AREA DEBRIS DEBRIS DEBRIS SURFACE TYPE 2 LOADING2 TOTAL TOTAL ASSUMPTIONS/NOTES (ft ) (gift ) (g) (Ibm) l .... a--..... -- --

-a __---- ...

Subject to Containment Spray 1,794.500 0.058 104.619 0.231 Due to only one sample available, 10% is added Due to only one sample available, 10% is added Submerged Post-Accident 2,773.000 0.058 161.666 0.356 to the debris loadin for margin NO' M M, S~

Hoeontalý.Peidestal Canl'urfacsYT6o Side Pedestal Crane 7.0 75.000 0.097 7.275 0.016 Due to no (or infrequent) cleaning, assume Polar Crane 1,802.354 0.181 326.226 0.719 higher debris load similar to floor vs. the e_qu*me.n.ts.urface loing.

Polar Crane Rails (Elevations 715'-6" and Due to no (or infrequent) cleaning, assume 3,646.863 0.181 660.082 1 1.455 higher debris load similar to floor vs. the 703'-6")

equipMentsu rface loading.

Steam Generators 409.488 0.097 39.720 0.088 Insulated diameter A nn7 Assume debris loading same as walls due to lack Pedestal Crane 200.000 0.076 15.200 0.034 of equipme-nt surface data Assume debris loading same as walls due to lack Polar Crane 4,444.852 0.076 337.809 0.745 of..ýg qui*p*ent surface data Assume debris loading same as walls due to lack Polar Crane Rail Supports 1,067.500 0.076 81.130 0.179 of eýuip ment surface data Steam Generator Sides 6,209.853 0.076 471.949 1.040 Insulated diameter; assume debris loading same as walls due to lack of equipment surface data same RCPs/Motor sides 1,570.796 0.076 119.381 0.263 Insulated diameter; assume debris loading as walls due to lack of equipment surface data Surface area per USAR Table 5.8-1 (assume Floor/Stair Grating (Vertical Surfaces) 9,920.000 753.920 1.662 80% of grating is vertical surface); assume debris

. ...... . loading similar to wall sample data -..

Pressurizer Relief Tank 41 .226 0.091 100% of tank surface; assume debris loading 542.448 Page 9 of 10

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination

7.0 CONCLUSION

S AND RECOMMENDATIONS 7.1 Conclusions 7.1.1 The total quantity of latent debris in Containment is 21.903 lbs.

7.1.1.1 The quantity of latent fibrous debris is 3.285 Ibs. This is below the administrative limit of 10 lbs.

7.1.1.2 The quantity of latent particulate debris is 18.618 lbs. This is below the administrative limit of 60 lbs.

7.2 Recommendations 7.2.1 No CR is required. Latent fiber and particulate debris quantities remain well below the administrative limits.

Page 10 of 10

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1 KEWAUNEEMNUCLEAR POWER PLANT LATENT DEBRtI WALKMOWN San*e 4 Filter & g Weight Inltft uuIu Seome Vacuum Aftr VacL~im Aua Type (Raoo, Equp, etc) Ei&n-Area (Approxnate) ILxW1 A_____IVI__ ( iJ 4, f'2Z / f Provid. a slwoh of the area below (kinldte conlalnment kCAt0IW IarefltrmMM Slnsurzý ý4 t Page 1 of 12

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1 KEWAUNEE NUCLEAR POWER PLANT LATENT DEBRIS WALKDOWN Sample S Fitr &Beg Weight IrihiaW Dan Before Vacuumr 11 ZL Ad lo-a.o; 4--

After Vacuum Area Type (Roar, Equip, 0to)

Elevatin£o, cm f.- J Area (ApproxAmaW) L x WL.- 1 J,7-o Pravide a dketch of the area be&w* (ncdude oontainment location nserence measuremernt):

4 SWWWM

<ý ý Oga% 77ode+64 Page 2 of 12

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1 KEWAUNEE NUCLEAR POWER PLANT LATENT DEBRIS WALKDOWN Satnpl 8 Ffter &Ba Weig InIw Din-Before Vacuum Alter Vacuum AMe TYpe (Flowr Equip. etc) L Elevation ~i  ? ~ 2 2 Amea(A~mlrnx~ale) [Lx W] (Pt 1 Jtf j 7 Pravdae a skcetch of fte area below (include cotairnment location refenreec.memaeurnets):

Al ecyViA07 cvr-31j34ý

&Le Opacvdor ~oe~)I

1. • A. 4 )LW W~kc 44(t)ppf , 4a 1(0 140f~ 1V Sigature ý08 Page 3 of 12

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1

,KEWAUNEE &LEAR POWER PLANT LATENT DEBRSF WALKDOWN Sample 7 FMer & W WO it ale Before Vacuwn After Vacuum

_,.*.~ ~ A AV ... A0:*.-

, -,* -o.

Area Type (Floo, Equip, atc) 60nr-Lo .

Area (Appmximate) (LxW1 . &A.b-27=

PrrM a eke=c od Mle ar bao (Munfctl con1tWnment loSion mlOrOWfM Mqna Mf)!

4:.n.P

¢-,d,,r-Signature 4:ý?.Oale Page 4 of 12

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1 KEWAUNEE NUCLEAR POWER PLANT LATENT DEBRIS WALKOOWN SaMe 8 Fifter &'Bag Welaf InImis . Dals Before Vacuum .. L& _2.L/4L /6-fl-c 1--f After Vecnum flea Type (Floo. Equip Mic) A2*-OI 1 t..

SEWatio 62_ (9ttc__ _

Area (Apprxknals)( Lx W) .... CI4- 27'-0t Provkle a swlth of the ala below (Include conlalnment localin reference measurements);

4 Signature ZSA Page 5 of 12

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1 KEWAUNEK NUCLICAB"PWER MLAW LATENT DE-BRIS WLALKROWN Swiple 9 A~fer &BegWool Dt OMOil After Vacum j Area Type (Flawr, Equip. etc) Zi.L L&

Area (Aqpo~ma~t) (LXW x Ats$~

J5i HL4d ProMuja sketcn coft area below (Includo cant~akmt Wekon reference measurenleiw4)

F-. i' I

$ionalite Dt Page 6 of 12

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1 KEWAUNEE NUCLEAR POWER PLANT LATENT DERIS WALKDOWN Sample l1 Fitter &Bag Weigh Initals 0818 Before VaMuwu 10J ( -ý MAftr Vacuum 14L0 i--> A2/ 0 Area Type (FlOor, Equip, etc) - -

..... I,.-,e m,, , O) L I: 4'* /O -.* 7-o 4-Eta, at,,,

(AWnnclu) (Lxm reea W1 AkL IL. d 0-> 77- c1 Prov~de aLeltreth of ft area below (include ooritakmeM lixcetinu Weerone inessubernwot).

lA Page 7 of 12

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1 KEWAUNEE NUCLEAR POWER LATENT DEBRIS.WALKDOWN Samle 11 Fiter &'fBtgW 't ktt IniW DOWA Befor Vacum ZQ. 5 aL L I Lk After Vacuwm IJH, o , Qt'J§91:

• io-a7- 0.--

Area Type (Moorý, iqwip etc) X *-*.

Asea (Avvoirote)IL xV) je.

AV2 VLf2@ 2 /0-;k7 Provide a skaldh A ftharea below (I decntimnmt locatbio re~erwof meaaureieuts 1*-4,I t-1A 7YF'N SWgOtur Date Me64 Page 8 of 12

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1 KEWAUNEE NUCLEAR POWER P T LATENT DEBRIS WALKDOWN Samwple 12 Filter &Bq Weght

• iMlal5 Dfte adfore Va0Jum q1i-3 Alter Vaouwn jobL ____ Ion-p)7- o4 Area Type (Floor, Equip, etc) Ekf.

Am .(Aproxlmale)tx P)'x3V2V i1L~4 Providle a skelMt d the area below (Include ccwitakmient localior reference measuremlents):

1~'

0o Signaure Daewd~Q Page 9 of 12

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1 KEWUNE N CLgAl EOM F LATENT DEBRIS WALKDOWN

$smpleg KJ Filter &Bag Weight Initial Do Before Vacuum ZQ2Q VM-Q- o4-After Vacuum Area Type (Floor. Equip, 9ec) " ,* ..

Elevailon __ _ __ _ _ _ __ _ _ _ __ _ _

Atea (Approximate) [L x WI 9(CdIL x~~~ lo/ 7- IL Provice a sketch of the area below (Include containment location reference measurements):

Signature D04-Page 10 of 12

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1 KEWAUNEENUCLEAR POWER PLANT LATENT DEBRIS WALKDOW, Sample 1j Filter &sag We80ht bItiars owe, Before V-Uum After Vacuum Area Type (Floor, Equip. eatc) D'4,-..

Elevation _________ j__la______it Area (Approximate) [L x W) Je 5 "f 7-/

Provk(e a sketch of the avea belo'w (include containment locaton refllonce mesureementa):

d J6)e-SIgnature 4ý Z Date -MOO Page 11 of 12

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 1 KEWAUNEE NUCLEAF ,,OWIER PLANT LATENT DEBRIS WALKDOWI Sampt*.J5 FIlter& Bag Weight Iniltals Dale eOiM'Vocuum .. o.*.... . L., (A*A o-.27-o 1!-

After Vacuum Area Type (Floor, Equip, etc) j..LL Elevation p 2 L ~ L/ ~7O-Area (Approxinat) [ILxWJ Si (W1/.- /0 Provide a sketch of IhS area below (include vonlainment location reference measurements):

'4

.1 oA~t;('1 4 46"~~i Aw4*10i 4&,4,v, 6c~4~

41*0k4.r -Sk 41

• 2:::~:~

Sigatue Date - 22AuL9-ý Page 12 of 12

Dominion Energy Kewaunee, Inc. Calculation Cl 1928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 2 AREA DETERMINATIONS 649'-6" Floor Elevation a1c.

1~

Wall t'-R"y 7'-7 IR" V-8` 71- 1/8 14'-7 51M" x '2 14'-7 518" x T-2" 19 1V-10 a/8" x T'-2" ý '/,

4- 1-(5'1-71/" + 3'-10 118") x 3'-2" 1----~

(7'-5 13/16" - 5'-7/'"x 3'-2" '-/

W4'-11 3/8" 10 1/8") x 3'-2"

• Y 1*

f29'-4 3/16") x 3-2" 1*~ 1* (I 1'-11/4"/4 x 3T-2" *1/2/ k5 (13'-8 7/16" + 2'-7 7,'8"* x '2 f -8 71"+2 -7718 -

x T--

3-2" + 8-3 3/8" + 14'-5 3116 + 10'-9 3/16") x 3'-2" 606'-0" Floor Elevation SG A Cavity Walls 1'-7 518" x 3'-2"

_____ _____T__1_ 10 5/8"x 3'-2* 2 __ I

__________________________ W-71/4 + 3-10 118") x 3-2" I1

____________________________ W-5 13/16" - 5'-7/4") x 3'-2" *__1/_

____ ________ ____ ___ (4-_-11 3/8"-3'-10 1/8") x3T-2"'*___/2 T-1Y" x 3'-2"

• YS 68-3 3/8" + 14'-5 3/16 + 10'-9 3/16") x T-2" (i R

....... I 0" -6" T-11/4-Wall 7A

Dominion Energy Kewaunee, Inc. Calculation Cl 1928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 2 AREA DETERMINATIONS Category Sub-Category Dimensions Area (ft2) Reference (13'-8 7/16" + 2'-7 7/8" 0") x 3'-2" (29.6710) S-235 (3'-2" + 8'-3 3/8" + 14'-5 3/16 + 4'-81") x 3-2" (96.7977) S-235 SG A Cavity Walls (5-8 7/16" + 2'-7 7/8") x 3-2" (26.5043) S-235

. (29'-4 3/16" - 2'-7 7/8" - 12'-6") x 3'-2" (44.9436) S-235 (6'-6"-1--1Y") x 3'-2" (17.0868) S-235 1'-1%" x 3T-2"

• V2 (1.7483) S-235 (4'-11 318"- 3'-10 1/8") x 3'-2"

• 2 (1.7483) S-235 (5'-71/," + 3'-10 1/8") x 3'-2" (29.9184) S-235 (T7-5 13/16" - 5'-7") x 3'-2"*1/2 (2.9770) S-235 (56-61/4" - 3'-7 5/8") x 3-2" * / (2,9852) S-235 592'-0" Floor Elevation .....

(Cont.)-7 5/8" x 3'-2" (11.5122) S-235 (Cont.) (8'-2" + 8'-0" + 3-6") x 3'-2" (62.2778) S-235 Columns 2'-6" x 2'-D" x 4 (20.0000) S-235 3'-0" x 2'-0" x 2 (12.0000) S-235 2T-0" x 2'-0" x 1 (4.0000) S-235 Regen Rx Wall 3'-7 9/16 x 4'-0" (14.5208) S-235

...... _ 6'-0" x (3-2" + 4'-41,W' + 4'-3 5/8" - 1'-6%") (61.9375) S-235 1V-6_/." x 6-0" - Y (4.5625) S-235 V1'-6"x 6'-0"

• 1/2,5625) S-235 6'-" x -0" 180000 S-235 Rectangular Area Adj. to SG 1B 19'-10" x 11'-2 9/16" 222.4019 S-250 666'-0" Pressurizer 2 Triangular Areas 6'-1 7/16" x 6'- 7/16" 37.4519 S-250 Missile Shield Rectangular Area between Triangular Area 7'-7 1/8" x 6'-1 7/16" 46.4722 S-250 RCP B West Wall T-9" x 12'-3/8" 21.0547 S-250 RCP B North Wall 3'-2" x 18'-4 5116" 58.1380 S-250 RCP B East Wall T-2" x 116-5 3116" 48.8689 S-250 RCP A East Wall 1'-9` x 15'-2 3/8" 26.5964 S-250 RCP A South Wall T-2" x 17-2 5/16" 54.4436 S-250 RCP A West Wall T-2" x 16'-5 3116" 48.8689 S-250 SGli ault Wal RCPfP= &a RCP & SG Vault Wall SG B West Wall 3'-2" x 21'-5 518" 67.9844 S-250 Tops SG B North Wall 3'-2" x 16'-8 9/16" 52.9262 S-250 SG B East Wall 3'-2" x 15F-1 3/8" 49.7101 S-250 SG B East Wall T-2" x 12'-13/8" 38.3628 S-250 SG A North Wall 3'-2" x 20'-1/4" 63.3993 S-250 SG A West Wall 3'-2" x 12'-5 3/16" 39.3689 S-250 SG A West Wall 3'-2" x 13'-11" 44.0694 S-250 SG A South Wall 3'-2" x 17-8 9116" 56.0929 S-250 SG A East Wall 3'-2" x 22'-8 13116" 71.9922 S-250 Page 2 of 8

Dominion Energy Kewaunee, Inc. Calculation C01928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 2 AREA DETERMINATIONS Category Sub-Category Dimensions Area (ft2) Reference Rx Vessel Elevation 623'-7" 22'-0 x 26'-6" 583.0000 S-258 &S-246 Rx Vessel Area 14'-0" D (153.9380) S-263 Mid Elevation 613'-6" Rectangle 22'-0" x 13'-3.24' 291.9400 S-258 &S-246 & Figure 1 Refueling CavityPool Mid Elevation 613'-6" Rectangle 11'-0.12"x 8'-11.76" 98.8698 S-258 & S-246 & Figure 1 Floor Mid Elevation 613'-6" Triangle 2-10.44" x 1-6.6" 2.2243 S-258 & S-246 & Figure 1 Mid Elevation 613'-6" Triangle 14'-11.52" x 8-11.44" 60.7376 S-258 & S-246 & Figure 1 Mid Elevation 613'-6" Triangle 5'-11.76" x 11 '-0.12" 32.9199 S-258 & S-246 & Figure 1 Fuel Transfer Elevation 608'-0" 106.0000 Calc. 2006-01660 (pg 29)

Vault B 616'-0" Platform below PZR 13'-6' x 14'-2" 191.2500 S-272, S-246 Vault B 609'-1" South Shelf 10'-6 3/8" x 19'-1 3/4" (max.) 201.6296 S-272, S-246 5-3 114" x 19'-1 3/4" (max.) 100.9145 S-272, S-246 Steam Generator A/B Vault B 609'-1" North Shelf 444.5423 S-272, S-246 Vault Floors Vault B 605'-4" Shelf 23'-2 5/8" x 19'-1 3/4" (max.)

Vault A 609'-1" South Shelf 10'-6 3/8" x 20'-1 3/4" (max.) 212.1608 S-273, S-246 Vault A 609'-1" North Shelf 5-3 1/4" x 20'-1 3/4" (max.) 106.1853 S-273, S-246 Vault A 605'-4" Shelf 23'-2 5/8" x 20'-1 3/4" ýmax.) 467.7611 S-273, S-246 USAR Table 5.8-1 Floor/Stair Grating USAR Table 5.8-1 Liner 105' D from 731'-6" to 606'-0" 41,398.3372 S-220 Transfer Canal 15'-2" x 10'-6" (159.2500) S-221 Containment Liner jQ1 to ................

SG A Cavity (11'V-5" + 6-3 9/16") x (El. 660'-0" - 649'-6" + 3'-4" + 2'-8") 292.2734 S-250 & S-273 SG A Cavity Outer Perimeter (El. 660'-0" - El. 649'-6") x (13'-11" + 4'-1 3/8" + 7-5 13/16" 736.8047 S-250 & S-273

+ 20'-0 1/4" + 32" + 3-2" + 10'-0" + 8-3 5/8") ....

SG A Cavity Inner Perimeter (El. 660'-0" - El. 606'-0") x (5'-7Y" + 3-10 1/8" + 8'-3 5/8" 2,046.9375 S-250 & S-273

+ 10'-0"+ 13'-11"- 1-1X"-2'-7 7/8") .....

RCP A Cavity (11'-5" + 6-3 9116") x (El. 660'-0" - 649'-6" + 3'-4" + 2'-8") 292.2734 S-250 & S-273 RCP A Cavity Outer Perimeter (El. 655'-6" - El. 649'-6") x (15-5 1/16" + 18'-4%" + 13'-11 3/16" 293.8438 S-250 & S-273

+ 1'-3 3116")

RCP A Cavity Inner Perimeter (El. 7/8"-+El.

655'-6"

- 2'-7 606'-0")

11'-5" x 9/16"1-

+ 6'-3 2'-6"++ 1-3 (10'-9 3/16" 3/16" 11'1-5"1 + 151-5

+ 6'-3 1/16" 9/16")S25 2,857.3359 S-250 & S-273 (10'-5" + 6'-3 9/16") x (El. 660'-0" - 649'-6" + 3-4" + 2'-8") 275.7734 S-250 & S-272 Vault Walls SG B Cavity SG B Cavity Outer Perimeter (El. 660'-0" - El. 649'-6") x (13'-11" + 4'-1 3/8" + 7-5 13/16" + 3'2" 526.5859 S-250 & S-272

+ 3'-2" + 10'-0" + 8'-3 5/8") .....

SG B Cavity Inner Perimeter (El. 660'-0" - El. 606'-0") x (5-714" + 3-10 1/8" + 8'-3 5/8" + 10'-0" 2,046.9375 S-250 & S-272

+ 113'-11"- 1'-1X"-2'-77/8")

SG B Cavity Inner Perimeter (Przr Side) (El. 660'-0" - El. 646'-0") x (14'-8") 205.3333 S-250 & S-272 RCP B Cavity (10'-5" + 6'-3 9/16") x (El. 660'-0" - 649'-6" + 3'-4" + 2'-8") 275.7734 S-250 & S-272 RCP B Cavity Outer Perimeter (El. 655'-6" - El. 649'-6")x (15'-5 1/16" + 18'-4Y" + 13'-11 3/16" + 1-3 3/16") 293.8438 S-250 & S-272 RCP B Cavity Inner Perimeter (El. 655-6" - El. 606'-0") x (10'-9 3/16" + 1-3 3/16" + 15'-5 1/16" 2,758.3359 S-250 & S-272

-2'-77/8" 10'-5"+6'-39/16"-2'-6"+10'-5"+6'-39/16")1 Page 3 of 8

Dominion Energy Kewaunee, Inc. Calculation C1 1928 Calculation/Evaluation Revision 0

Title:

Latent DebrisDetermination Attachment 2 AREA DETERMINATIONS Category Sub-Category Dimensions Area (ft2) Reference PZR Cavity Outer Perimeter (El. 666'-0" - El. 649'-6") x (8'-2" + 3'-0 9/16" + 3-0 9/16" + 5F-3 3/8" 733.3392 S-250 &S-272 VaultWalls_(Cont.)_ + (2"3'-9 91/16") + (2 * (6-0"+ 3'-2" 0 9116"),. 2-0.5))

Vault Walls (Cent.) PZR Cavity Outer Perimeter (SG Side) El. 666'-0" - El. 660'-0") x 17' 102.0000 S-250 &S-272 1-6" 1 x 5'1"86_17 -5_&S-4 Rx Vessel Elevation 623'-7" to 649'-6" 26'-6" x 25'-11" 686.7917 S-258 &S-246 Rx Vessel Elevation 623'-7" to 649'-6" 22'-0" x 25'-11 " 570.1667 S-258 &S-246 Rx Vessel Elevation 623'-7" to 649'-6" 26--6" x 25'-1 1" 686.7917 S-258 &S-246 Elevation 613'-6" to 649'-6" 14'-9 7/8" x 36'-0" 533.6250 S-258 &S-246 Elevation 608'-0" to 649'-6" 5-8.825" x 41'-6" 238.0198 S-258 &S-246 Refueling Cavity Pool Elevation 608'-0" to 649'-6" 10'-6 3/4" x 41'-6" 438.3438 S-258 &S-246 Elevation 608'-0" to 649'-6" 2'-0" x 41'-6" 83.0000 S-258 &S-246 WallsElevation 608-0" to 649-6" 4'- 3/4" x 41'-6" 196.2604 S-258& S-246 Elevation 608'-0" to 649'-6" 0'-11 5/16" x 41'-6" 39.1224 S-258 & S-246 Elevation 608'-0" to 649'-6" 3'-4" x 41'-6" 138.3333 S-258 &S-246 Elevation 608'-0" to 649'-6" 4'-1 12" x 41'-6" 171.1875 S-258 &S-246 Elevation 613'-6" to 649'-6" 12'-6 5/16" x 36'-0" 450.9375 S-258 &S-246 Elevation 613'-6" to 649'-6' 22'-3 x 36'-0" 801,0000 S-258 &S-246 041 ffm ,-,'~ Wwl .Ry ______________

Dome Vents - Angled 16"D x (1U'x.6) x 4 502.6548 M-684 Plan Dome Vents - Supply ,Horizontal 24"D x 29' x 2 182.2124 M-684 Plan Dome Vents - Supply - Horizontal 24"D x 8' 25.1327 M-684 & M-693 Sec E-E Vent Supply - Horizontal 48"D x 40' 251.3274 M-685 & M-693 Sec B-B Vent Supply - Horizontal 48"D x 46' 289.0265 M-685 & M-695 Sec B-B Vent Supply - Horizontal 40"D x 40' 209.4395 M-685 Vent Supply - Horizontal 24"(x72") x 60' 120.0000 M-685 Vent Supply - Horizontal 24"(x60") x 30' 60.0000 M-685 Vent Supply Rx Support - Horizontal 20"D x 25' 65.4498 M-685 Plenum Inlet - Horizontal 34"D x 12' x 2 106.8142 M-685 & M-693 Sec B-B Purge Su [y- Horizontal 42" (x30" x 6' 211.0000 M-685 & M-694 Sec A-A Ventilation/Ductwork CRDM - Horizontal 18"D x,3,3" 77.7544 M-690 CRDM - Horizontal 32"D x 5' 20.9440 M-690 CRDM Shroud - Horizontal 5.5' x 8' 44.0000 M-690 Cavity A Vent Supply - Horizontal 23' x 40" (x30") 76.6667 M-686 Cavity B Vent Supply - Horizontal 32'x 40" (x40") 106.6667 M-686 Cavity A Vent Supply - Horizontal 9.5' x 45" (x40") 35.6250 M-686 Cavity A Vent Supply - Horizontal 8' x 26" (x24") 17.3333 M-686 Cavity B Vent Supply - Horizontal 10' x 30" (x25") 25,0000 M-686 Cavity A Vent Supply - Horizontal 22" (x14") x 21' 38.5000 M-686 Cavity B Vent Supply - Horizontal 22" (x14") x 21' 38.5000 M-686 Cavit B PZR Vent Sul- Horizontal 22" x1 x 10- 18.3333 M-686 Dome Vents -Vertical 16"D x(10'x 1)x4 167.5516 M-684 Sec A-A I Dome Vents - Vertical 18" x 28" x 56'x 4 1,381.3333 M-684 Sec A-A Page 4 of 8

Dominion Energy Kewaunee, Inc. Calculation C11928 Catculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 2 AREA DETERMINATIONS Category Sub-Categor .Dimensions Area (ft22) Reference I')nmA. VeFnts - Riinnlv - Vprtirnl 94I'D 49' x 9 615.7522 1M-693 Sec D-D &E-E DomeV entSuplVrSp .24" ica x 44'x 26.0000...

Vent Hot Supply - Vertical 72"x 44' 264.0000 M-685 Vent Hot Supply - Vertical 60" x 16' 80,0000 M-685 Plenum - Vertical 34" x 36" x 12.5' 106.2500 M-685 & M-693 Sec B-B Vent Supply Rx Support - Vertical 20"D x 37' 193.7315 M-693 Sec A-A Rx Gap Vent - Vertical 24"D x 18'x 2 226.1947 M-693 Sec B-B Vent Supply- Vertical 48"D x 1T 213.6283 M-693 Sec B-B Purge Exhaust - Vertical 40"D x 24' 251.3274 M-685 & M-694 Sec A-A Purge Supply - Vertical 30" x 42" x 14.5' 174.0000 M-685 & M-694 Sec A-A Vent Suoolv- Vertical 48"D x 17' 213.6283 M-695 Sec B-B Ventilation/Ductwork {':RFlM - VP~rticn~i 1813x8_5' x 18"D x 825'x 3 y

CRDIVI - Vertical  ?+ 8'x 8'x 2 (Cont.) CRDM Shroud - Vertical 5,5' x L Cavity A Vent Supply - 40" (x x 10'x2 I-Cavity A Vent Supply - 40' (x x 13'x 2 1~

Cavity B Vent Supply -VE 40" (x x 16'x 2 I-Cavity B Vent Supply - VE 40"Lx x 6'x 2 Cavity B Vent Supply - Ve 40" (x inl'x 2 Cavity A Vent Supply - 40" (x x 9.5'x 2 24" (x x 8'x 2 Cavity A Vent Supply - Ve 25" (x x 10'x 2

-' 14" (x x 21'x 2 7* M'l tx B\ 14" (x )x21'x 2 x 10'x 2

• 14 - E-318 14 - E-318 14 - E-318 x 38' 14 - E-318 x39' 14 - E-318 x 39-x 39' 14 - E-318 73 x 38' 14 - E-318 x 15' + 24" x 23' 14 - E-318 x 20' 14 - E-318 y l1t' 14 - E-318 x 14' y 9(' 14 - E-318 Cable Trays x 20-4"x30' 14 - E-318 30' xx 30' 14 - E-318 x50' 14 - E-318 4-x50' 14 - E-318 4-x 50' 14 - E-318 14 - E-318 14 - E-318 I-14 - E-318 x 85' 127. 14 - E-318 x 85' 127. 14 - E-318 Page5 of 8

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 2 AREA DETERMINATIONS Category Sub-Category Dimensions Area M2) Reference 1CX304N 12"x 85' 85.0000 IE-314- E-318 lCT304S6 12" x 85' 85.0000 E-314 - E-318 1CX303S6 18" x 85' 127.5000 E-314 - E-318 BLU 21 12" x 85' 85.0000 E-314 - E-318 lCL11N 4' __18",_,,_,.6My.0000 E-316 &Cable RacewaI Ak 1CL102N 4'x 18" 6.0000 E-316 & Cable Raceway App.

1CL102N 18" 2'x 6.0000 E-316 & Cable Raceway App.

1CL103N 12'x 12" .1.0000 E-316 & Cable Raceway App.

ICL104N 12" 22'x 12.0000 E-316 & Cable Raceway App.

1CL106N 18'4x 12" 18.0000 E-316 & Cable Raceway App.

ICLI07N 18'x 12" 18.0000 E-316 & Cable Raceway App.

ICL1I08N 23'x 12" 23.0000 E-316 & Cable Raceway App.

ICL1I09N 20'x 12" 20,0000 E-316 & Cable Raceway App.

1CL10S5 25'x 12" 25.0000 E-316 & Cable Raceway App.

1CL115N 43'x 18" 64000 E-316 & Cable Raceway App.

1CLI11N 30'x 18" 45.0000 E-316 & Cable Raceway App.

1CLI12N 43'x 18" 64.5000 E-316 & Cable Raceway App.

1CL113N 27'x 18" 40.5000 E-316 & Cable Raceway App.

1CL114N 20'x 18" 30.0000 E-316 & Cable Raceway App.

1CL115N 20'x 18" 30.0000 E-316 & Cable Raceway App.

1CLllS5 23'x 12" 23.0000 E-316 & Cable Raceway App.

Cable Trays (Cont.) 1CL12S5 47'x 18" 70.5000 E-316 & Cable Raceway App.

1CL13S5 33'x 18" 49.5000 E-316 & Cable Raceway App.

ICL14S5 48'x 18" 72.0000 E-316 & Cable Raceway App.

1CL15S5 35'x 18" 52.5000 E-316 & Cable Raceway App.

1CLIS5 27'x 12" 27.0000 E-316 & Cable Raceway App.

lCL2S5 27' x 12" 27.0000 E-316 & Cable Raceway App.

1CL3S5 27'x 12" 27.0000 E-316 &Cable Raceway App.

lCL4S5 3'x 18" 4.5000 E-316 &Cable Raceway App.

lCL5S5 3'2x 18" 4.5000 E-316 &Cable Raceway App.

1CL6S5 16' x 12" 16.0000 E-316 &Cable Raceway App.

1CL7S5 16' x 12" 16.0000 E-316 &Cable Raceway App.

1CL8S5 27' x 12" 27.0000 E-316 &Cable Raceway App.

1CL9S5 38'x 12" 38.0000 E-316 &Cable Raceway App.

1CT101N 25' x 12" 25.0000 E-316 &Cable Raceway App.

1CT102N 27' x 12" 27.0000 E-316 &Cable Raceway App 1CT103N 25'x 12" 25.0000 E-316 &Cable Raceway App.

1CT104N 27'x 12" 27.0000 E-316 & Cable Raceway App.

1CT105N 32'x 12" 32.0000 E-316 &Cable Raceway App.

1CT106N 45'x 12" 45.0000 E-316 &Cable Raceway App.

1CT107N 30' x 12" 30.0000 E-316 &Cable Raceway App.

1CT108N 42'x 12" 42.0000 E-316 & Cable Raceway App.

1CT109N 25' x 12" 25.0000 IE-316 &Cable Raceway App.

1CT10S5 30' x 12" 30.0000 *E-316 & Cable Raceway App.

1CT110N 27' x 24" 54.0000 :E-316 & Cable Ra,,ceway App.' ..

1CT111N 20 x 12" 20.00001 E-316 &Cable Raceway App.

Page 6 of 8

Dominion Energy Kewaunee, Inc. Calculation Cl 1928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 2 AREA DETERMINATIONS Category Sub-Category Dimensions Area 1COT1 28' x 12" 28 & Cable Raceway App.

lCT1 28'x 12" 28 & Cable Raceway App.

1CT2 5'x 12" 5 & Cable Raceway App.

1CT3 35' x 12" 35 & Cable Raceway App.

I CT4 43'x 12" 43 & Cable Raceway App.

1 CT5 43'x 12" 43 & Cable Raceway App.

1 CT6 43' x 12" 43 & Cable Raceway App.

1CT7 45'x 12" 45 & Cable Raceway App.

1 CT8 40'x 12" 4C4 & Cable Raceway App.

1CT9 45' x 12" 45 &Cable Raceway App.

ICx1 30'3x 12" R 16 & Cable Raceway App.

1CXl 15'x 18" 7 is &Cable Raceway App.

1CX1 132'x 18" 48 & Cable Raceway App.

ICxl 130'x 18" 45 & Cable Raceway App.

1 CXl 45' x 18" 67 & Cable Raceway App.

1COX1 42' x 18" 63 IV & Cable Raceway App.

1Ccx1 40' x 18" 60 16 & Cable Raceway App, 1Cxl 43' x 18" 64 & Cable Raceway App.

1Cx1 35' x 18" 52 & Cable Raceway App.

Cable Trays (Cont.) iCXl 52' x 18" 78 & Cable Raceway App.

30' x 18" 45 & Cable Raceway App.

32' x 18" 48 & Cable Raceway App.

S30'x 12" 30 & Cable Raceway App.

25' x 18" 37 & Cable Raceway App.

25' x 12" 25 & Cable Raceway App.

25'x 12" ,25 & Cable Raceway App.

8' x 18" 12 & Cable Raceway App.

20' x 18" 30 & Cable Raceway App.

35' x 18" 52 & Cable Raceway App.

42' x 18" 63 & Cable Raceway App.

45' x 18" 67 & Cable Raceway App.

43' x 18" 64 & Cable Raceway App.

45' x 18" 67 & Cable Raceway App.

• 171 Y IR" ri & Cable Raceway App.

INUL- INUL .il - UI. .. U.V- V.I UOy( -11YtlU= LULCIIYýUUiIVIIvcU, UUL 1I[11 I* C conservative value and will also encompass the small amount of piping that will be submerced oost-accident.

"I"'* ' * " *... * "' " 1'" Wf) " # i-M ALLIE-0004 Pedestal Crane VTM ALLIE-0004 Trolley Top Surface 31'-3" x 14'-0" 437.5000 XK-126-5 Bridge Top Surface 97'-5 7/8" x 7-0" (value doubled to account for additional surfaces) 1,364.8542 XK-126-1 Polar Crane Trolley Side Surfaces (2 Sides) 14'-0" x 8'-0" + 31'-3" x 8'-0" 724.0000 XK-126-6 Bridge Side Surfaces (4 Sides) 97'-5 7/8" x 9'-6 1/2" 3,720.8524 XK-126-1

____________ '~'~' t~~'y~ ~~ K ~ t '~' ________Ilk-__

Page 7 of 8

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 2 AREA DETERMINATIONS Category Sub-Category Dimensions Area (ft2) Reference Containment Wall Radius 52'-6" 8,659.0148 XK-106-27 Radius to Inside Crane Rail 46'-7 3/4" 6,8355834 XK-106-27 P o la r C ra ne R ails RI E WE' gW IL g7 "_ _._ __,_ _ _ _ _ _ _ _ _ _ _ __"

Vertical Supports 9"(2 sides) x 5" (2 sides) x 10'-2" high 23.7222 XK-106-27 Top of Upper Cylinder Dia.: 14'- 7 3/4"+1.5' 204.7438 XK-100-1 Insulation thickness: 1.5' added for sides and 0.75' added for top Steam Generators Lower Cylinder Height: 37'-0.82"+.75' Dia.: 11'-3" + 1.5' 1,514.8249 XK-100-1 Upper Cylinder Height: 30'-7.18"+.75' Dia,: 14'-7 3/4" +1.5' 1,590.1013 XK-100-1 Insulation thickness: 1.5' added for sides and 0.75' added for top Motor Top Radius: 5'-0" (Assumed with Insulation) 78.5398 XK-310-22 RCPs/Motors Motor and Pump Sides 5'-0" Radiusx 25'-0' Hih Assumed with Insulation) 785.3982 M-365 & XK-310-19 Pressurizer Relief Tank )*"%PRT (Cylinder) Lenfth: 17'-7"

• " '.'* Dia.: 8'...

!* . ,- *-= .*" **"" * ,.. *"** ' ' - ,"" 542.4483 XK-100-161 Figure 1: 613'-6" Elevation of Refueling Cavity Pool Page 8 of 8

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 3 Sape ye 1:Foors andHoriontal Structures tUL- 1.886 for 90% probability that the mean will be less than x + t*s/(n" 2) with 3 samples Assumes Normal Distribution Sample # Mass Area Mass/Area (g) ft2) (g/ft) 12 0.7 33 0.02121212 13 0.15 56 0.00267857 4 1.8 9.625 0.18701299 Sample Mean (x) = 0.070 g/ft2 Eq. 4-1 2

Sample Std Dev (s) = 0.101 gift Eq. 4-2 2

90% Confidence Limit Mean (AL/L) = 0.181 gift Eq. 4-3 Page 1 of 6

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 3 Sample Type 2: Containment Liner tUL= 3.078 for 90% probability that the mean will be less than x + t*s/(n" 2) with 2 samples Assumes Normal Distribution Estimate with 2 Samples Sample # Mass T Area 2

Mass/Area (g) (ft ) (g/ft2) 7 0.1 51.8 0.0019305 9 0.3 72 0.00416667 Sample Mean (x) = 0.003 g/ft2 Eq. 4-1 2

Sample Std Dev (s) = 0.002 g/ft Eq. 4-2 90% Confidence Limit Mean (AVL) = 0.006 g/ft2 Eq. 4-3 tUL= 1.886 for 90% probability that the mean will be less than x + t*s/(nt/ 2) with 3 samples Assumes Normal Distribution Estimate with 3 Samples Sample Mass Area Mass/Area

.(g) (Wt) (g/ft2 )

5 0 22.4 0 7 0.1 51.8 0.0019305 9 0.3 72 0.00416667 Sample Mean (x) = 0.002 g/ft2 Eq. 4-1 2

Sample Std Dev (s) = 0.002 g/ft Eq. 4-2 2

90% Confidence Limit Mean (RV) = 0.004 g/ft Eq. 4-3 Page 2 of 6

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 3 Sample Type 3: Walls, Vertical Equipment Surfaces, Other tUL= 3.078 for 90% probability that the mean will be less than x + t*s/(n1 2) with 3 samples Assumes Normal Distribution Sample #

Mass Area 2 Mass/Area

( /ft2 )

(ff )

10 0.5 34.9 0.01432665 15 2.0 45.0 0.04444444 Sample Mean (x) = 0.029 g/ft2 Eq. 4-1 Sample Std Dev (s) = 0.021 g/ft2 Eq. 4-2 90% Confidence Limit Mean (pvL) = 0.076 g/ft2 Eq. 4-3 Page 3 of 6

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 3 Sample Type 4: Ventilation/cluctwork. Cable Trays Vertical Horizontal Since only one sample was obtained for the vertical and horizontal ductwork, a 10% margin will be added to the loading for conservatism. As more samples are taken during future walkdowns, the debris loading will be obtained by using the t-distribution 90% confidence level.

Vertical Loading with 10% Margin: .003 g/ftz Horizontal Loading with 10%Margin: .058 g/ft2 Page 4 of 6

Dominion Energy Kewaunee, Inc. Calculation C11928 Ca Iculatio n/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 3 Sample Type 5: Horizontal Equipment Surfaces tUL= 3.078 for 90% probability that the mean will be less than x + t*s/(nu' 2 ) with 3 samples Assumes Normal Distribution I

Sample #

Mass Area Mass/Area 2

(g) (fW ) (g/ft2) 6 8

0.3 0.8 21 3.4 10 0.08823529 0.080 Sample Mean (x) = 0.084 gift2 Eq. 4-1 Sample Std Dev (s) = 0.006 gift2 Eq. 4-2 90% Confidence Limit Mean (tvL) = 0.097 g/ft2 Eq. 4-3 Page 5 of 6

Dominion Energy Kewaunee, Inc. Calculation C11928 Calculation/Evaluation Revision 0

Title:

Latent Debris Determination Attachment 3 Equation Sheet for Sample Type 1: Floors and Horizontal Structures tuL= 1.886 for 90% probability that the mean will be less than x + t*s/(n"2 ) with 3 samples Assumes Normal Distribution Mass Area Mass/Area Sample # (g) (ft2 ) (g/ft 2) 0.7 33 12 =C7/D7 0.15 56 13 =C8/D8 1.8 9.625 4 =C9/D9 2

Sample Mean (x) = =AVERAGE(E7 :E9) gift Eq. 4-1

ýSQRT(t/(COUNT(E7:E9)-

1)*(SUM(E7^2,E8^2,E9^2)-

(SUM(E7 :E9)^2/COUNT(E7:E 2

Sample Std Dev (s) = 9)))) gift Eq. 4-2 90% Confidence =E 1 +$C$2*E12/(SQRT(COU Limit Mean (*UL/)= NT(E7:E9))) 2 gift Eq. 4-3 Page 6 of 6

Serial No.10-025 Docket 50-305 ENCLOSURE C-2 (RAI 8) LATENT DEBRIS PROCEDURE CM-AA-CRS-101, REVISION 2 PROCEDURE ATTACHED

Nuclear Fleet oeDominionw Technical Procedure

Title:

Latent Debris Collection and Sampling Procedure Procedure Number Revision Number Effective Date and CM-AA-CRS-101 2 Approvals On File Revision Summary Section 1.1 - Added "[CM 8.1.4]."

Section 1.3 - Added "[CM 8.1.1] [CM 8.1.2] [CM 8.1.3] ([CM 8.1.5] KPS only)."

Section 3.5

" Added "Use the site's current latent debris evaluation or tracking document to determine the quantity and locations of samples to be collected (See Section 5.2)."

• After "should be" replaced "identified" with "listed or documented."

• After "walkdown" deleted "in order" and "assure a comprehensive collection population."

Section 4.8 - Move first sentence to last sentence position.

Section 5.3, last sentence - Changed "bag and cloth or filter" to "bags and cloths or filters."

Section 5.4

"(old)

The sample area size should be an area between 1 ft 2 and 100 ft 2 . Samples are required from each of the following surface types in the areas subject to containment spray or post-LOCA flooding.

" Horizontal concrete surfaces

" Vertical concrete surfaces

" Containment steel liner

" Equipment surfaces such as ductwork, piping, fan coils, valves, etc.

SELECT the specific location for sample collection as previously determined during the walkdown plan and obtain sample. MEASURE the area from which the sample was taken and record the results on Attachment 1.

" (new)

The sample area size should be selected to provide a representative quantity of debris on the surface type.

MEASURE and DOCUMENT the sample dimensions of the surface area from which the sample will be taken and RECORD the results on Attachment 1.

Functional Area Manager: Manager Nuclear Site Engineering Programs INFORMATION USE

DOMINION CM-AA-CRS-101 REVISION 2 PAGE 2 OF 10 Revision Summary (continued)

Sections 5.9 and 5.10 (old section) - Reversed order.

Section 5.10 (renumbered 5.9)- Moved "Provide results to GSI-1 91 Site Owner" to Section 5.11 (new section).

5.9 (renumbered 5.10)

" After "zero" added "and not within the scale accuracy."

" Changed "REPEAT Section 5.8" to "REPEAT Sections 5.3 through 5.9, as necessary."

Section 5.12 (new section)

" STORE the sample collection bags in a proper containment storage area, or as advised by Health Physics staff, until notified by Engineering that the samples may be discarded.

Section 5.13 (new section)

" WHEN notified by Engineering that samples may be discarded, THEN CONTACT Health Physics for disposal Guidance.

Section 8.1.1 - Added "(See Section 1.3)."

Section 8.1.2 - Added "(See Section 1.3)."

Section 8.1.3 - Added "(See Section 1.3)."

Section 8.1.4 - Added "(See Section 1.1)."

Section 8.1.5 (new section) - Dominion Letter to NRC, Serial No.05-212, Kewaunee Power Station, Millstone Power Station, Units 2 and 3, North Anna Power Station, Unit 1 and 2, Surry Power Station, Units 1 and 2, Response to Generic Letter 2004-002, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors (See Section 1.3)

Section 8.3.12 (new section)- Dominion Letter to NRC, Serial No.05-212, Kewaunee Power Station, Millstone Power Station, Units 2 and 3, North Anna Power Station, Unit I and 2, Surry Power Station, Units 1 and 2, Response to Generic Letter 2004-002, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors Section 8.3.13 (new section) - Kewaunee COMTRACK 2005-167, NRC Commitment to Develop a Procedure to Routinely Sample Containment Latent Debris Attachment 1 - Reformatted table and added Sample Surface Type Code "OTH (Other)." Added form number.

INFORMATION USE

DOMINION CM-AA-CRS-101 REVISION 2 PAGE 3 OF 10 TABLE OF CONTENTS Section Page 1.0 PURPO SE ....................................................................................................................................... 4 2.0 SPECIA L TO O LS AND EQ UIPM ENT ......................................................................................... 4 3.0 PREREQ UISITES ............................................................................................................................ 4 4.0 PRECA UTIO NS A ND LIM ITATIO NS .......................................................................................... 5 5.0 INSTRUCTIO NS .............................................................................................................................. 5 6.0 ACCEPTA NCE A ND SIG N O FF ................................................................................................. 7 7.0 RECO RDS ....................................................................................................................................... 7 8.0 A DM INISTRATIVE INFO RM ATIO N ........................................................................................... 7 8.1 Com m itm ents ........................................................................................................................ 7 8.2 Definitions .............................................................................................................................. 8 8.3 References ............................................................................................................................. 8 ATTACHMENTS 1 Latent Debris Walkdown Sample Record Sheet (Form No. 729451 (Jan 2010)) .................. 10 INFORMATION USE

DOMINION CM-AA-CRS-1 01 REVISION 2 PAGE 4 OF 10 1.0 PURPOSE 1.1 This procedure outlines the guidelines and methods for the collection and sampling evaluation of latent debris (particulate and fibrous debris, i.e., dust, dirt, lint, fibers, shavings, etc.) in containment. [CM 8.1.4]

1.2 This procedure outlines the walkdown activities for collection of debris samples, required equipment, collection methods, and proposed locations.

1.3 This procedure is used to gather latent debris samples to determine ifthe current quantity of latent debris in containment (debris inventory) remains bounding by the debris assumption for design basis for the Emergency Core Cooling Sump (ECCS)

Recirculation Strainer. [CM 8.1.1] [CM 8.1.2] [CM 8.1.3] ([CM 8.1.5] KPS only) 2.0 SPECIAL TOOLS AND EQUIPMENT 2.1 Instruments and equipment for latent debris walkdown collection and sampling activities may include, but are not limited to:

" Personnel Protective Equipment (to be determined by the governing Radiation Work Permit (RWP) and Site Safety Manual

" Masslin cloth (at least 50 approx. 24" x 24")

" HEPA vacuum cleaner designated for use in Radiologically Controlled Area (RCA) with removable filter element

" Calibrated scale with an accuracy of at least 0.1 gram

" Plastic ziplock bags (at least 50), bags sized to contain one Masslin cloth or HEPA vacuum cleaner filter element

" Approved ink type markers

" Location maps

" Labels (at least 50) minimum size 1" x 3"

" Narrow brush with long bristles and long handle

" Portable illumination, i.e., flashlight

" Tape measure 3.0 PREREQUISITES 3.1 Walkdown personnel shall be aware of the potential for inaccuracies involving the initial and post collection weights of specimen containers and specimen samples taken for debris determination inventory. This discrepancy has been described in Sargent & Lundy Performance Improvement Process (PIP) 2005-0278 (Reference 8.3.6).

3.2 Walkdown personnel should be familiar with the walkdown plan by the GSI-1 91 Site Owner, and knowledgeable on use of the equipment used for sampling.

INFORMATION USE

DOMINION CM-AA-CRS-101 REVISION 2 PAGE 5 OF 10 3.3 Health Physics (HP) shall be notified prior to performing the walkdown inside containment, as well as requisite HP briefing.

3.4 The sampling frequency shall be every fifth refueling outage after completion of the sump modification, if containment wash downs are performed during each refueling outage. The sampling frequency shall be every other outage after completion of the sump modification if containment wash downs are not performed. Sampling shall also be performed after any invasive or extended maintenance has occurred such as a steam generator replacement, or more frequently ifdetermined by the GSI-191 Site Owner.

3.5 Use the site's current latent debris evaluation or tracking document to determine the quantity and locations of samples to be collected (See Section 5.2). Sample area locations should be listed or documented on the respective site containment area maps prior to walkdown to identify areas for HP assessment, preparation of RWP requirements, and to maximize ALARA while collecting the samples in containment.

4.0 PRECAUTIONS AND LIMITATIONS 4.1 Sampling for latent debris collection shall commence near the end of the outage after bulk work in containment is completed.

4.2 Perform walkdown, and latent debris collection in a safe manner practicing ALARA.

4.3 Prior to starting work in a Radiation Area, have HP survey the work area. Ensure the proper RWP has been issued.

4.4 Ensure components and structures will not be damaged (gouged, dented, deformed) or operationally altered while gaining access or while obtaining debris samples.

4.5 Steps may be performed concurrently or in any sequence consistent with good engineering and construction practices.

4.6 During collection of sample, minimize to greatest extent possible, the creation of fugitive airborne dust and dirt. Give special attention to assure the items within the vicinity of the sample collection, are covered and protected as required.

4,7 Provide adequate supplemental lighting as necessary to perform sample collection activities.

4.8 If samples are collected from cable trays, energized equipment, electrical cabinets, and equipment with moving parts, ensure equipment is placed in a safe condition prior to obtaining sample. Personnel collecting samples on all energized equipment shall be qualified and have completed the necessary site electrical training.

4.9 Remove all collected samples from the RCA, in accordance with HP directives. If contaminated after evaluation, then dispose of in accordance with HP procedures as Radwaste.

Site 5.0 INSTRUCTIONS Engineeringor Designee 5.1 Walkdowns may require climbing ladders or scaffold access. ADHERE to site procedures governing the use of these items for access and approval from HP.

INFORMATION USE

DOMINION CM-AA-CRS-101 REVISION 2 PAGE 6 OF 10 5.2 REFER to the site specific design basis calculation for guidance on general area locations, number of samples, and sampling methodology. In general, sample locations should include floors, containment liner, horizontal, and vertical ventilation duct, walls, horizontal and vertical equipment, horizontal, and vertical piping, and miscellaneous items such as structural steel, junction boxes, and monitoring devices.

The specific number and location of sample locations should approximately correspond to the original site specific sampling locations performed for the original walkdown where samples were obtained that established the original latent debris design input. As a minimum, there should be at least three samples from each distinctive surface type.

5.3 PLACE Masslin cloth or HEPA vacuum filter element inside the respective plastic collection bag. The collection bag should have an identification label with a unique identifying number correlating to all pre-determined locations in containment where samples are desired. PRE-WEIGH the sample bags and cloths or filters element and RECORD on Attachment 1.

5.4 The sample area size should be selected to provide a representative quantity of debris on the surface type.

MEASURE and DOCUMENT the sample dimensions of the surface area from which the sample will be taken and RECORD the results on Attachment 1.

5.5 WIPE with the Masslin cloth or vacuum the selected area collecting as much of the debris as possible and deposit debris and cloth or vacuum filter element in the collection bag.

5.6 The actual sample area locations may be changed during the walkdown ifthe original location can not be accessed, or due to HP discretion based on ALARA considerations, or interference with other on-going outage activities. Clearly identify location on Attachment 1. Consider supplementing sample location information using marked up area maps.

5.7 For cylindrical horizontal sections (pipe, equipment, etc.) WIPE only the top portion of the surface. On the Latent Debris Walkdown Sample Record Sheet (Attachment 1), RECORD the length and the outside diameter of the section.

5.8 WEIGH each sample on a calibrated scale and record on Attachment 1.

NOTE: For samples measured at zero to less than 0.1 gram, round up to 0.1 gram.

5.9 TABULATE the results.

5.10 IF the weight of the post walkdown sample is questionable (i.e., less than zero and not within the scale accuracy, Reference 8.3.6), THEN INVESTIGATE the discrepancy and obtain another sample from a similar surface at comparable plant location. REPEAT Sections 5.3 through 5.9, as necessary.

5.11 PROVIDE results to the GSI-191 Site Owner.

INFORMATION USE

DOMINION CM-AA-CRS-101 REVISION 2 PAGE 7 OF 10 5.12 STORE the sample collection bags in a proper containment storage area, or as advised by Health Physics staff, until notified by Engineering that the samples may be discarded.

5.13 WHEN notified by Engineering that samples may be discarded, THEN CONTACT Health Physics for disposal Guidance.

Site 6.0 ACCEPTANCE AND SIGN OFF Engineeringor Designee 6.1 Verify that all work areas are cleaned and all collection bags and Masslin cloths brought in containment are accounted for and removed from containment.

6.2 Complete the required work entries on the Work Order package.

NOTE: Formally document results (e.g., Technical Report, Engineering Transmittal, etc.).

GSI-191 Site 6.3 Compare tabulated results against data in the design basis. For non-acceptable Owner results, initiate CR for follow-up evaluation and to clean containment, if necessary.

6.4 Confirm that a repetitive work order/activity exists to evaluate the need for a sampling activity for the next refueling outage to meet the frequency requirements of Section 3.4.

Site 7.0 RECORDS Engineering or Designee Complete all documentation and related documents completed as a result of performance or implementation of this procedure and submit to Records Management in accordance with site procedures.

8.0 ADMINISTRATIVE INFORMATION 8.1 Commitments 8.1.1 Dominion Letter to NRC, Serial No. 08-0017, Kewaunee Power Station NRC Generic Letter 2004-02, Supplemental Response Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors (See Section 1.3) 8.1.2 Dominion Letter to NRC, Serial No. 07-0797, Millstone Power Station Units 2 and 3 Supplemental Information of Corrective Actions in Response to NRC Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurizer Water Reactors (See Section 1.3) 8.1.3 Dominion Letter to NRC, Serial No. 08-0019, North Anna Power Station Units 1 and 2 Supplemental Response to NRC Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurizer-Water Reactors (Implied reference in NRC GL 2004-02, Plant Audit of North Anna Power Station ADAMS ML072740400) (See Section 1.3)

INFORMATION USE

DOMINION CM-AA-CRS-101 REVISION 2 PAGE 8 OF 10 8.1.4 Dominion Letter to NRC, Serial No. 08-0018, Surry Power Station Units 1 and 2 Supplemental Response to NRC Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors (See Section 1.1) 8.1.5 Dominion Letter to NRC, Serial No.05-212, Kewaunee Power Station, Millstone Power Station, Units 2 and 3, North Anna Power Station, Unit 1 and 2, Surry Power Station, Units 1 and 2, Response to Generic Letter 2004-002, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors (See Section 1.3) 8.2 Definitions 8.2.1 Latent Debris Unintended dirt, or combination of particulate and fibrous matter such as dust, dirt, lint, shavings, grit, sand, paint chips, fibers, pieces of paper (shredded or intact), plastic, tape, or adhesive labels, fines or shards of thermal insulation, fireproof barrier or other materials that are already present in the containment prior to a postulated break in a high-energy line inside containment. Potential origins for this material include activities performed during outages and foreign particulates brought into containment during outages.

8.3 References 8.3.1 NRC Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors 8.3.2 NEI 04-07, Pressurized Water Reactor Sump Performance Evaluation Methodology, Revision 0, including NRC Safety Evaluation dated 2004 8.3.3 NEI 02-01, Condition Assessment Guidelines: Debris Sources Inside PWR Containment 8.3.4 Dominion Topical Report DOM-QA-1, Nuclear Facility Quality Assurance Program Description 8.3.5 American Society of Mechanical Engineers, ASME NQA-1-1994, Quality Assurance Requirements for Nuclear Facility Application 8.3.6 Sargent & Lundy Performance Improvement Process (PIP) 2005-0278, Latent Debris and Label Walkdown Deficiencies 8.3.7 Dominion Letter to NRC, Serial No. 08-0017, Kewaunee Power Station NRC Generic Letter 2004-02, Supplemental Response Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors INFORMATION USE

DOMINION CM-AA-CRS-101 REVISION 2 PAGE 9 OF 10 8.3.8 Dominion Letter to NRC, Serial No. 07-0797, Millstone Power Station Units 2 and 3 Supplemental Information of Corrective Actions in Response to NRC Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurizer Water Reactors 8.3.9 Dominion Letter to NRC, Serial No. 08-0019, North Anna Power Station Units 1 and 2 Supplemental Response to NRC Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurizer-Water Reactors 8.3.10 Dominion Letter to NRC, Serial No. 08-0018, Surry Power Station Units 1 and 2 Supplemental Response to NRC Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors 8.3.11 NRC Generic Letter 2004-02, Plant Audit of North Anna Power Station (ADAMS ML072740400) 8.3.12 Dominion Letter to NRC, Serial No.05-212, Kewaunee Power Station, Millstone Power Station, Units 2 and 3, North Anna Power Station, Unit 1 and 2, Surry Power Station, Units 1 and 2, Response to Generic Letter 2004-002, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors 8.3.13 Kewaunee COMTRACK 2005-167, NRC Commitment to Develop a Procedure to Routinely Sample Containment Latent Debris INFORMATION USE

a 0

Z Latent Debris Walkdown Sample Record Sheet Z

~Dominion A. B. C. D. E. F. G. H. I.

Sample No. Surface Surface Location Surface Type Surface Area Initial Sample Post-Walkdown Debrs Weight Debris Loading Type/Description (elevation, Code (ft2) Bag Weight Sample Bag (grams) G - F (g/ft2) H/E and Size (ft x ft) quadrant, other) (grams) Weight (grams) 4 4 4 4 + + I

-I I. 4 4 4 Sample Surface Type Code:

HCT- Horizontal Cable Tray Station: L] KPS E] MPS FI NAPS LM SPS VCT - Vertical Cable Tray HE - Horizontal Equipment HD - Horizontal Duct VD - Vertical Duct Unit: [L] 1 E12 F-13 OTH - Other Prepared by (print/sign): Date:

0-c 0;UhZ Form No. 729451 (Jan 2010)

Serial No.10-025 Docket 50-305 ENCLOSURE D (RAI 9) DEBRIS INTERCEPTORS INSTALLED IN THE PLANT DEBRIS INTERCEPTOR Page 1 of 2

Serial No.10-025 Docket 50-305 ENCLOSURE D (RAI 9) DEBRIS INTERCEPTORS INSTALLED IN THE PLANT Page 2 of 2

Serial No.10-025 Docket 50-305 ENCLOSURE E-1 (RAI 13/15/16) ARL PRESENTATION FROM 9/15/09 TELECONFERENCE WITH NRC ARL PRESENTATION DATED SEPTEMBER 15, 2009

~'

[ 2 Kewaunee Power Station 1~ NRC Agenda Setting Meeting 9/15/2009 79 ALDEN---~

RAI E9j: Concentrated sources of drainage

• No concentrated spray and drainage sources are located in the immediate vicinity of the strainer

• The closest source is modeled in the transport calculation and the flume wall calculation

" The influence of the source can be seen in the calculated approach velocity profile

• The drainage source influence was represented in the large flume test 0-140 Wekgte Avrage and Average Approach Velocities 0.100 oO040 00,20 0000 0 to W1. *. 20ZP) 2 30 3 35

-M El 3a-e: CFD modeling of containment flow Simulations were conducted using Fluent and followed the standard calculation methodology

• The standard k-E model was used for turbulence calculations

• Debris transport calculations were conservatively performed at the water level for the start of recirculation High transport fractions were obtained for most zones up to a tumbling velocity of 0.2 ft/sec AIV' ---

Y

~

El 3a-e: CFD modeling of containment flow

" Detailed accounting was performed to model spray and break flow drainage into the recirculation pool

" Concentrated sources of falling water were treated ideally converting all water potential energy into kinetic energy

" The debris interceptor curb was modeled with few simplifying assumptions

• No assumptions with regard to debris interceptor debris loading were necessary No credit was taken for lift-over-curb transport limitations over the debris interceptor curb ALDE Sovn flow prbemssne19

IE 5: Turbulence in containment and flume /test configuration Flume configuration based on long-term recirculation conditions

- Achieved 14 minutes after recirculation start Water level in containment for analysis and test maintained at 40.5"

- 40.5" is water level for the start of recirculation

- Actual water depth is more than 2 ft higher for long-term recirculation

• Velocity and turbulence levels in vicinity of strainer are low

• Containment structure divides break flow into three sources distributing break flow momentum 2.00e-01 100.-02 I I 9.50e-03 1*800-01 I 1.0e-01 9.008-3 1.70"-01 8.500-03 1.60e-01 8,00.-03 1.500-01 7.500-03 1.406-01 7 D0-03 1.30e-01 6.500-03 12*0e-01 6.008-03 1100e-01 5.50-03 1000-01 5 0Oe..03 900.-02 8.00e-02 4.50e-03 4,00-03 7 000-02 3.508-03 600M02 3.000-03 500&02 2.50e-03 3.00e-02 2000-03 1 50.-03 23 000-02 OOe-0 1.00e03 1.00e-02 5,000-04 0,00+00 0.00.400 Long-term recirculation velocity magnitude (ft/s) Long-term recirculation TKE (ft2/s 2 )

AL D S

El 5: Turbulence in containment and flume / test configuration

" Debris interceptor, despite its low height blocks most break flow from reaching strainer

• Flume Reynolds numbers are in the turbulent range

" Flume effective turbulence is on par with that calculated in containment

• Turbulence levels calculated in containment correspond to a maximum of 0.02 ft/sec RM 0.0025 0.002 Distance from Velocity Flume Width Hydraulic Radius screen (ft) (ft/sec) (in) (ft) Reynolds #

0.0015 1 0.10 10.4 0.39 6704 2 0.10 9.9 0.37 6045 3 0.10 11.3 0.41 6644

" 0.001 6 0.08 14.3 0.51 6435 10 0.09 11.7 0.42 6617 0.0005 21 0.12 8.9 0.33 6821 25 0.13 8.5 0.32 6852 0

0 5 10 15 20 25 30 35 30 0.13 8.4 0.32 6861 Distance Back From Strainer (ft)

ALDEN

El 6: Pool fill transport & distance traveled by debris

" Preferential pool fill transport is limited except during sump C fill-up

• Sump C fill-up preferentially causes debris to move away from strainer bank

• No credit for this transport is taken in the analysis

• The average distance traveled by debris is greater than 30' when considering calculated zone exit flow splits opnp TempMat calculated transport fraction was increased by 20% of debris generated for conservatism in determining test quantity Transport testing at Alden showed 3x - 4x approach velocity profile only yielded partial transport of TempMat smalls.

ALDEN Solving flow problems sit-ice 1894

Serial No.10-025 Docket 50-305 ENCLOSURE E-2 (RAI 13/15/16) ARL PRESENTATION FROM 11/10/09 TELECONFERENCE WITH NRC ARL PRESENTATION DATED NOVEMBER 10, 2009

1'~

C01 Kewaunee Power Station NRC Follow-Up Meeting 11/10/2009

-'7ý ALD0EN 0~

M Kewaunee Containment

• Sump area is covered and does not receive spill flow

• Break flow does not directly impact Zone 1

• Break flow separates into three parts Break flow sources:

• Two ledges & one hatch

• 22% of flow is through hatch ALD0EN -;e

E15: Velocity & Turbulence

• Test velocity based on long-term recirculation conditions

- Conditions after RWST injection has ceased

- Water level is assumed to remain at that for start of recirculation

• True water level is 70% higher 5.00e-01 1.00e-02 I I 4 75e-01 9.50e-03 4.50e-01 9.00e-03 4.25e-01 8.50e-03 4.00e-01 8.00e-03 3.75e-01 7.50e.03 3.50e-01 7.00"-03 3.25e-01 6.50e-03 3.00e-01 6.00e-03 2.75e-01 5.50e-03 250e-01 5.00e-03 2.25e-01 4.50e-03 200e-01 4,00e-03 1.75e-01 3.50e-03 1.50e-01 3.00e-03 1.25e-01 2.50e-03 100e-01 2.00e-03 7.50e-02 1.50e-03 5.00e-02 1.00e-03 2,50e-02 5.00e-04 0.00Xe+C 0.00e+00 Velocity magnitude (ft/s)

ALDE Sovn flo @0blrn sic 1894

E15: Velocity & Turbulence

" Area immediately around strainers is very calm

" Dominant strainer approaches are slow: '~'0.12 ft/s

" Break flow does not aggressively leave Zone 1 Dominant exit paths of Zone 1 away from strainer bank 1 2 faZone 22% of break flow 6% of break flow approaches strainers through opening ALDE Sovn flo prblm sic09

Zone 1 Flow Pattern

• Break flow from hatch streams along floor

• Debris interceptor curb turns flow vertically upward I

• Flow pattern sets up large toroidial "roller" I

100..CC 9.00-1 850.001 7.06-01 75.-Cl, S.S0-01 Toroidial flow Dattern 5.00.-01 I

45.-Cl0 4.76.-0l 4.600-01 4260-01 I50S-C 4.000-01

.00"6-1 3.76e-01

.00&-02

ýý,ý,Iz 3.50.-01 32541-0

.00.8Cl 3.00)-01 2.75.-Ol 2.10a-01 226*-01 2.00e-01

1. 75.-Cl t .See-01 1260-01 1.000-01 7.50*-02 5C.O~-02 2.00*-02 2Cfl-02

Zone 1 Flow Pattern

• Net flow through from Zone 1 to strainer bank is low

• Significant areas of reverse flow in center of opening I

1350e-01 1.ý35e.0 120e-01 1.05e-01 9.00e-02 7.50e-02 6.00e-02 4.50e-02 3.000-02 11.50e-02 0.00e400

-1.50e-02

-3.00e-02

-4.50e-02

-6.00e-02

-7.500-02

-9.00e-02

-1.05e-01

-1.20e-01

-1+356-01

-1.500-01 Thru-flow velocity (Positive is to strainer bank)

ALDE Sovn flo prblm sine 89

E15: Turbulence comparison

• Flume Reynolds numbers are in the turbulent range

• Flume effective turbulence is on par with that calculated in containment

• Turbulence levels calculated in containment correspond to a maximum of 0.02 ft/sec RMS 0.0025 Distance from Velocity Flume Width Hydraulic Radius 0.002 screen (ft) (ft/sec) (in) (ft) Reynolds #

1 0.10 10.4 0.39 6704 0.0015 2 0.10 9.9 0.37 6045 3 0.10 11.3 0.41 6644 0.

6 0.08 14.3 0.51 6435 10 0.09 11.7 0.42 6617 0.0005 21 0.12 8.9 0.33 6821 25 0.13 8.5 0.32 6852 0 30 0.13 8.4 0.32 6861 0 5 10 15 20 25 30 35 Distance Back From Strainer (ft)

ALDEN *S~

E16: Debris Addition Distance

• Pool fill transport:

- Transport is out of Zone 1 into Zones 2,4 and 6 predominantly

- 15% inactive sump hold-up not credited e Mostly suspended debris

- Preferential transport to Zone 6

" Zone 6 contains > 60% of volume

" Not credited in pool fill analysis Sump C opening ALDE /1 Sovn flo prblm sic 18943

El1: Debris Addition Distance

• Debris Transport is based on peak transport conditions

- Near end of RWST injection

-* '- . C 0 - Occurs only short-term at recirculation start

_ Large fraction of debris transports:

,,. More than 75% for vtumble =0.06 ft/s 2 I,'. - More than 66% forVtumble 0.12 ft/s

__

• Performed analysis determining a measure of distance traveled by debris SLook at flow balance by zone first Ze -

ALDN 0Slvn flo prblm s inc 189

E16: Debris Addition Distance U U Z63 2292 83%

Z64 -1713 Z13 3438 46%

ALDE

• I E16:,' Debris Distance j

" Complex containment flow pattern

• NO net flow from Zone 1 to strainer train 17

" Zone 1 & Zone 6 have two exits:

- Divide Zone 1 into areas according to flow fraction e Nearly 50/50 split

- Divide Zone 6 into areas according to flow fraction 9 Very little flow approaches strainer train from left from Zone 6

-i*< .7,,i I

"4 V

DEN 0Sovn flo prolem -sic 189

E16:m Debris Distance

• Example distance calculation for 0.06 ft/s proj. surface

- Logical division of Zone 6

- Simple segments from centroid to calculate distance ZONE DISTANCE (ft Zil 41.14 Z13 39.43 ZONE4 Z2 39.56 Z3 24.18 ZONE13 Z4 30.74 Z5 6.10 Z61 61.73 ZONE5 Z63 88.06 KEWAUNEE CONTAINMENT ZONE3 VELOCITY = 0.06 FT/S 1ý 0 10 wmwmmmlý50w W0 ALDE

j 1~~

I 16PDers Distance

• Apply to all initial tumbling velocity surfaces

• Weight the distance from each zone by local debris:

0

- Allows distance to properly represent initial debris distribution

- Calculation results:-

- For 100% transportable debris: 51 ft

- For transport velocity 0.06 ft/s: 50 ft

- For transport velocity 0.25 ft/s: 45 ft

- Minimum debris distance (for v = 0.66 ft/s): 38 ft IA

• Adding debris at ~*'29ft from the strainer is conservative V

ALDE Sovn flo prblm since 1894

Serial No.10-025 Docket 50-305 ENCLOSURE E-3 (RAI 14) CONTAINMENT DRAINAGE NORTH STAIRWELL Page 1 of 3

Serial No.10-025 Docket 50-305 ENCLOSURE E-3 (RAI 14) CONTAINMENT DRAINAGE Containment floor plan - one elevation above the basement (sump) level. Worst case postulated RCS break locations (RCS Loops) are within the concrete vaults (compartments) shown on previous page. Smaller breaks outside the compartments do not generate large quantities of debris that could block the unobstructed south stairwell at this elevation, or the north or south stairwells at the upper containment elevations.

Page 2 of 3

Serial No.10-025 Docket 50-305 ENCLOSURE E-3 (RAI 14) CONTAINMENT DRAINAGE L-

-'.. .- Steam Generator

_Aý Aý1_ 1 Vt r

• /t-x, :4k.-

,#*7ft*j*r .. b Reactor Coolant Pump Pressurizer i I,,h 1"4 r*L,=',IP" A,

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mttirVI_ - .I

- I ill I' ~. -.- ,'

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'u.n I I' I4#-----t * *  :..,T ;Iaaauuu axon I I-

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2' Vaul Wal(

Au~ uf '-I

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J [

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• t Owl 4006 L

• • 4f'.

kt~f I Im If

• I

• 0 ~~h- [~-~

~ 1V 1 J

+/-UEIJT"~'

~ 4 Drainage Path out of /

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Containment Sump (basement elevation)

]

Page 3 of 3

Serial No.10-025 Docket 50-305 ENCLOSURE F-1 (RAI F.19.A) EXCERPT FROM CLEAN STRAINER HEAD LOSS CALCULATION 7.0 Calculation(s)

In order to determine the Total Corrected Clean Strainer Head Loss two (2) distinct calculation methodologies are employed as described in section 5.0 Methodology. Each methodology is utilized to separately calculate the head loss for the strainer and for the pipe and fittings.

7.1 Clean Strainer Head Loss As summarized in [Reference 9.3], PCI developed a head loss curve as a function of strainer exit velocity for the test strainer, PCI Prototype II. The subject curve supports the determination of strainer head loss for strainers of different diameter internal core tubes from the prototype that was tested (NOTE: The subject head loss determination must be corrected for the Kewaunee strainer assemblies). PCI also considered a number of minor adjustments to address other physical differences between the Kewaunee strainer and the PCI Prototype II, such as the differences in strainer length between the Prototype II strainer and the Kewaunee strainer, and the specific penetration velocity through the Kewaunee strainer plates.

7.2 Clean Strainer Test Data In order to calculate the Clean Strainer exit velocities, PCI utilized Equation 1 from [Reference 9.4]. The calculation is as follows.

Equation I V.1 = Qgt, I Aqx [Reference 9.4]

Where, Qs, = strainer water flow rate, gpm x 0.002228 to convert to ftl/sec Ax =exit area, or cross section area of the inside of the strainer's core, ft2 Vex = Strainer Exit Velocity, ft/sec As discussed in [Reference 9.4], the equation for the strainer only (i.e.,

without any pipe and/or fitting losses) Clean Head Loss is given by Equation 2 below.

Equation 2 H. = A+ K1 v V + K2 (Vex 2 1 2g) [Reference 9.4]

Page 1 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE F-1 (RAI F.19.A) EXCERPT FROM CLEAN STRAINER HEAD LOSS CALCULATION Where, v = water's kinematic viscosity, ftlsec (a function of water temperature) g = gravitational constant, which is 32.2 ft / see2 A = a constant with a very small value of 0.002205 feet of water - 0, as defined in [Reference 9.3], and can therefore be ignored.

K,- a coefficient multiplied by v to allow adjustment to the water temperature K2 = another coefficient that is multiplied times the dynamic head of the water at the strainers exit.

In [Reference 9.3], it is also shown that these coefficients, K(, and K2 have the following values (determined by a regression analysis of the test data):

K1 = 1,024 and K2 = 0.8792 With the values of the coefficients determined and utilizing Equation 2, the Base Head Loss, HLea was calculated for different water temperatures where the value of kinematic viscosity, v is selected based on the design basis water temperature. Kewaunee has specified that the water temperature for long term cooling following the initiation of a LOCA is 65 0 F [Reference 9.11. Accordingly, the actual base Clean Strainer Head Loss can be computed using the value of Exit Velocity, Vex for the particular water flow rate. Selecting a value of v for the particular water temperature from [Reference 9.7], the Exit Velocity can be computed using Equation I and the values of specified water flow rate values, respectively, for the Kewaunee strainer. Each strainer's core tube has an 18.00 inch outside diameter and a 0.06 inch wall thickness [References 10.1 - 10.7, inclusive). Therefore, the value of internal cross sectional area of the core tube can be computed by Equations 3 and 4 as follows.

Equation 3 AX = n Dex 214 where D= = inner core tube diameter Equation 4 D.= outer diameter - 2 x core tube wall thickness

= 17.88 inches Page 2 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE F-1 (RAI F.19.A) EXCERPT FROM CLEAN STRAINER HEAD LOSS CALCULATION Therefore, Ax = 1.744 ft 2 Using Equation I above and the value for Ax computed above, we can then calculate the values for Exit Velocity, V8x, for the strainer assembly using the specified flow rate of 1920 gpm.

Vex = OB I Ak.

= 1920 gpm x 0.002228 ft3 /s / gpm 1 1.744 ft2

= 2.453 ft/s The resultant value for Vex was then utilized to calculate the Clean Strainer Head Loss from the previously discussed equations as follows, HLst.*r= K1 V V.V.+ K2 (Vex2 1 2g)

= (1024) (1.138 x 10-) (2.453) + (0.8792) (2.4532I 64.4)

= 0.02859 + 0.08215

= 0.111 Table I provides a summary of the values obtained from the subject equations and the resultant Clean Strainer Head Loss for the strainer assembly.

Page 3 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE F-1 (RAI F.19.A) EXCERPT FROM CLEAN STRAINER HEAD LOSS CALCULATION Table I - Summary of Calculated Strainer Only Clean Strainer Head Loss Parameter Value Reference Total Suction Flow, gpm 1,920 9.10 Water Temperature, OF 65 9.1 Water Kinematic Viscosity, ft21sec 1.138 x 10"' 9.7 Internal Core Tube Outer Diameter, Inches 18.00 9.5 Internal Core Tube Thickness, Inches 0.06 9.5 Internal Core Tube inner Diameter, inches 17.88 Equation 4 Internal Core Tube Cross-Sectional Area, ft2 1.744 EquaUon 3 Design Strainer Exit Velocity, ftlsec 2.453 Equation I Calculated Uncorrected CSHL, feet of water 0.111 Equation 2 Page 4 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE F-2 (RAI F.19.A) EXCERPT FROM TOTAL HEAD LOSS CALCULATION 7.2 Strainer Debris Laden Head Loss The Kewaunee Debris Laden Strainer Head Loss tests performed at ARL are summarized in Table 4.

AREVA Tests Nos. 3 and 9 [Reference 9.5] are the Design Basis Test and the Supplemental Design Basis Test for Kewaunee, respectively.

Both Kewaunee Design Basis tests are intended to show recirculation at 1,920 gpm with a water level above the top of the Kewaunee strainer.

AREVA Test No. 9 Supplemental Design Basis Test was performed with an increased debris load to add debris inventory margin, Additional information regarding both the Clean Head Loss and Debris Laden Head Loss testing that was performed at ARL is specifically discussed in detail in [Reference 9.5].

Table 4 - ARL Test Debris Laden Strainer Head Loss Test Strainer Debris Test Laden Head Temperature, Loss, ft of water OF Test No. 3 Design Basis Test 0.51036 105.8 Test No. 9 Supplemental Design 1.66970 116.1 Basis Test NOTE: Debris laden head losses were the measured head losses minus the ARL piping and the Kewaunee clean strainer head losses.

PCI utilized the head losses associated with both Test 3 and Test 9 ARL test results, respectively in combination with the Kewaunee post-LOCA specified recirculation temperature (i.e., 65 'F) to determine the various Kewaunee Strainer Total Head Losses.

7.2.1 Temperature Correction Strainer Debris Laden Head Loss The dynamic viscosity of the specific test water (i.e., 105.8 'F and 116.1 OF, respectively) and the post-LOCA temperature (i.e., 65 "F) is determined by linear interpolation utilizing dynamic viscosity values taken from [Reference 9.7]. Table 5 provides a summary Page 1 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE F-2 (RAI F.19.A) EXCERPT FROM TOTAL HEAD LOSS CALCULATION of the dynamic viscosity associated with the various test and post-LOCA water temperatures that are utilized in this calculation.

Table 5 - Water Dynamic Viscosity Test / Event Temperature, 'F Dynamic Viscosity,2 Ib,-

sift Debris Testing 69 2.06462 x 10"'

(Clean Strainer Head Loss Test)

Debris Testing 105.8 1.33909 x 10.'

(Test 3 - Design Basis)

Debris Testing 116.1 1.20832 x 10"O (Test 9 - Supplemental Design Basis)

End of Post-LOCA 65 2.18108 x 10' Period (End of Post-LOCA Recirculation Period)

The head loss for low velocity water in the laminar flow region through a debris bed of fibers plus particulate is linearly dependent on the water's dynamic viscosity. The Kewaunee specified post-LOCA water temperature is specified. in [Reference 9.1]. The debris head loss requires correction to this temperature to determine the head loss at the Kewaunee specified post-LOCA temperatures. See Section 7.2.2 for temperature correction methodology. The strainer debris laden head loss for low velocity water flow through a debris bed of fibers plus particulate is linearly dependent on the water's dynamic viscosity [Reference 9.19].

7.2.2 Post-LOCA Temperature Correction Strainer Debris Laden Head Loss A head loss correction utilizing Assumption 3.4, which is based on the standard debris head loss equation [Reference 9,111, can be used to calculate a temperature adjusted debris head loss, HLTA.

The HLTA adjusted temperature can be calculated by taking a ratio of dynamic viscosity values at the two different temperatures being Page 2 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE F-2 (RAI F. 19.A) EXCERPT FROM TOTAL HEAD LOSS CALCULATION considered (i.e., the test water temperature and the Kewaunee specific post-LOCA sump water temperature).

HLTA = HLE)L,C (PiST I J TT)

Where HLDL.C= corrected, Debris Loaded Head Loss, ft PST = dynamic viscosity at the Kewaunee Design Basis specified temperature of 650 F pTT '= dynamic viscosity at the various average test temperatures of 69 °F, 105.8 °F, and 116.1 OF HLTA = temperature adjusted debris head loss, ft Applying the HLTA equation to the ARL measured head loss with the three water viscosities (i.e., two (2) average test water temperatures and Kewaunee specified post-LOCA water temperature), the value of HLTA is calculated by the above equation. The HLTA is added to the clean strainer head loss that results in the total head loss for the Kewaunee ECCS based on the various specified post-LOCA water levels and temperatures.

Table 6 in Section 7.3 provides a summary of the Kewaunee ECCS head losses based on the Kewaunee specified post-LOCA water level and temperature.

Page 3 of 4

Table 6 - Strainer Debris Laden Total Head Loss Test Results Clean Head CSHL ARL Clean Head Debris Head Loss, Debris Laden Total Head Loss, Regression Loss, (Table 5) Head Loss, Loss, Temperature Formula, ft of Temperature Temperature Temperature -1 Corrected, ft of water at OF Corrected, ft of Corrected, ft of Corrected, ft of water at OF [Reference 93] water at OF water at OF water at OF

[Reference 9.3] [Reference 9.4] M m

x 65 65 65 105.8 116.1 65 65 0 m

Design Basis 0.365 0.111 0.01807 0.51036 N/A 0.8313 1.1034

-1 Supplemental 0.365 0.111 0.01807 N/A 1.66970 3.0139 3.2860 Basis 0z r-(C)

NOTES: 1. 'Design" corresponds to full submergence conditions [Reference 9.1]. -0

2. The Clean Head Loss (Temperature Corrected) is based on the Clean Head Loss determined in calculation TDI-6008-05. The 0

Clean Head Loss has been temperature corrected for the Kewaunee specified post-LOCA recirculation temperature. The Clean Head Loss for Kewaunee is a "worse case" head loss that may not be applicable to all of the various ECCS operational scenarios.

However, it does provide a 'bounding worse case" head loss for Design Basis conditions that was conservatively utilized for all.

Kewaunee head loss determinations.

3. The Debris Laden Head Loss (Temperature Corrected) is based on Sections 7.2.1 and 7.2.2 and the test data of Table 4. r-

4. The Total Head Loss (Temperature Corrected) is determined by subtracting the CSHL Regression Formula value from the Clean 0Mr-Head Loss (Temperature Corrected) which results in head losses from only the strainer discharge piping and assembly, adding the ARL Test Clean Head Loss (Temperature Corrected) value, and adding the Debris Laden Head Loss (Temperature Corrected) which cumulatively results in the maximum Kewaunee strainer head loss (clean strainertstrainer assembly losses plus debris (i.e., CD fibrous, particulate, miscellaneous, and chemical precipitates) laden losses).

0

5. The values reflected herein may not show trailing digits, which simply means the checking of calculations can yield slightly different (z I-values than has been calculated for the calculation. These rounding errors are considered insignificant and therefore acceptable. 0 Any rounding errors are bounded by the uncertainty applied to the Clean Strainer Head Loss. Z U) 0 0

0 Z CD 0

01 0Q M C) 0J

-~~~y - I- .r'

~~-n 0)

- PC Z 03 CCCD 0

~

4' ~ ~ -~ 17 Z CD 0 r (DOc~

-n, (0M G) -

FLUME LENGTH DIMENSIONS (INCHES) C G CD N) 0 8-3,:8 mz I iý

ý I- it,

.12ý

• iI 71 13i8 12 Gc) 0 a:

0n FLUME WIDTH DIMENSIONS (INCHES) 0 0

0 z

CD 0 C,, C) 0n

Flume Width vs. Distance-from Strainer 16 . .. .. .....

"11 (0

-1n r-C 0 1:23a4 5678 9 1011 12.13141.516 17 1819 2021 22 2,24 2526 27 29 29. 4631: 2.

m Distance from Strainer (ft).

Um mz CD r--U)

CCo 0 >

-9, zO 0M Flume-Width at Flume Width at om DiOtniefrorn. Point A Iftl Linear Intaerpolation Velcityjft/s " Dit n refrom Poi nt A Distance from z0 fft' PointAlin) 1.0O 0.104 0.869 10 3/8 1.396 0.138 0.829 10 C

0 G 3.000 0.096 0.939 ii 2/8 -- !

6.000 0.076 L189 14 2/8 10.000 0.093 0.972 115/8 21.000 0.22 0.741 8 718 Cn CD 25.000 0.128 0.706 84/8 0 0

30.000 0.130 0.697 8.3/8 0 z

c77 0

CD Figure A-6: Flume Width vs Distance from Strainer C)

CQ U1 (31

Serial No.10-025 Docket 50-305 ENCLOSURE G (RAI F.19.C.VI) FLUME DESIGN LAYOUT AND PHOTOGRAPHS STRAINER MODULE Page 4 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE H (RAI F.19.C.XV) PHOTOS OF DEBRIS ADDITION DURING LARGE SCALE TESTS Latent Fines

-*11 [Calcium Silicate Page 1 of 5

Serial No.10-025 Docket 50-305 ENCLOSURE H (RAI F.19.C.XV) PHOTOS OF DEBRIS ADDITION DURING LARGE SCALE TESTS Dirt/Dust S Coatings Tin (Zinc surrogate)

Page 2 of 5

Serial No.10-025 Docket 50-305 ENCLOSURE H (RAI F.19.C.XV) PHOTOS OF DEBRIS ADDITION DURING LARGE SCALE TESTS Coatings Acrylic Powder Coatings Acrylic Chips Page 3 of 5

Serial No.10-025 Docket 50-305 ENCLOSURE H (RAI F.19.C.XV) PHOTOS OF DEBRIS ADDITION DURING LARGE SCALE TESTS Fine TempMat I Fine Owens Corning Page 4 of 5

Serial No.10-025 Docket 50-305 ENCLOSURE H (RAI F.19.C.XV) PHOTOS OF DEBRIS ADDITION DURING LARGE SCALE TESTS TempMat Smalls

[chemical Debris Page 5 of 5

Serial No.10-025 Docket 50-305 ENCLOSURE I-1 (RAI 23 & F.19.C.XIV) CLEAN STRAINER HEAD LOSS TEST DATA Figure 8-1: Temperature Corrected Clean Strainer Head Loss vs. Flow Rate Fl Raft vs. Cean Stnvkw Hed Las 2 y = 4E-07x + 4E45z + 0.0004 Fe = 0,M8 0.0300-0.0250-0.0200 S0.0150" 0.0100 0.0060-0.0000 S0.00 70.00 90.00 110.00 130.00 150.00 170.00 190.00 210.00 230.00 Fow RM (pM)

Note that a polynomial trend line of a 2"' order was used to model the clean strainer head loss versus flow and is shown in Equation 8-I.

Equation 8-1: Clean Strainer Head Loss Trend Line Equation y=4E-07*x2 + 4E-05 *x+0.0004 Where, y = head loss (ft of water) x = flow rate (gpm)

The raw head loss data and flow data collected during testing is displayed in Figure 8-2.

Page 1 of 2

Figure 8-2: Test I Raw Data (Flow and Head Loss) 250 0.035 225 0.032 90 0,029 200 0) 0.026 175 0.023 C-)

0.02 mm I >zo

-o 0.017 0 CD-f) 0.014 m _

0.011 m 0.008 0 50 CD 0.005 25 m 0.002

-Ii cD H

o 4- 0.001 o=_

0 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70,00 80.00 -Z Time (Minute})

CDO" n Measured Flow Rate

• Measured Head Loss (n00 ON) 0101

Figure 8-3: Test 3 Raw Data (Flow and Head Loss) 0.65 . ..........

---

................- 225 Increased Measured Head 0.6 -- - Loss due to a Flow Adjustment

0. to 215 p .7

-200 0.55' Maximum Measured Design Basis Flow Head Loss Reached ,, 7 0.5 -IRate (136.9 gpm) -:----------

0.45--

,E 150~- M 09 0.4 *** -

0 "J 0.35 Chemical Debris Test Termination 125 w* Batching Compete Ciera Met mm v_--- 0. - - - -- - - - - - - - --- - - - - - - - - - - - - - - - - - - - - 10 "0_C r-

"* 0.25 . . . . ... . .. 4 100.L2"oZ

(: zo 0-Batching .- h StaBed * ~~75

• mC 3 ;1 0 .2 -:- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - U m Small Fibrous Decreased Measured Head Debris Complete Loss due to a Flow -,

0.15, Adjustment to -69 gpm 50 0 0.1 -- -------- Fine Fibrous Debris -----..... - I --------------------.L .

Complete ' ,25 -

0.05 --

Fine Particulate 0- Debris Complete '0 or 0 0.00 4.00 8.00 12.00 16.00 20.00 24.00 28.00 32.00 (n Time (Hours) (nu_

T trn

- Measured Head Loss -- Measured Flow Rate M CD 0

00

(.1-Z

> 0 0 WIC:

Figure 8-4: Test 9 Raw Data (Flow and Head Loss) 90 2 150 -n 1.9 140 1.8 130 xU) 1.7 1.6 120 mH 1.5 110 U0 1.4 100 1.3 c

1.2

0. I- m

. 11 80 mz m0 U09 70 " Z CD 0.9 U z

""0.8 60 C 0"-h r-H m 50 N 0.7 m "i-U>

0.6 - 40 0.5 0 30 I-0 .410 0.3 20 l

c I

04 10 m C

0

-I 0 r--

0.00 4.00 8.00 12.00 16.00 20.00 24.00 28.00 32.00 O0 C,,

CD Time (Hours) m 0 C,,

- Measured Head Loss - Measured Flow Rate CDO0 H>

CA)C C

W 0o (C)N)

Serial No.10-025 Docket 50-350 ENCLOSURE I-4 (RAI F.19.C.XIV) PHOTOS OF FLUME DRAIN DOWN Page 1 of 4

Serial No.10-025 Docket 50-350 ENCLOSURE I-4 (RAI F.19.C.XIV) PHOTOS OF FLUME DRAIN DOWN

! I Page 2 of 4

Serial No.10-025 Docket 50-350 ENCLOSURE I-4 (RAI F.19.C.XIV) PHOTOS OF FLUME DRAIN DOWN DEBRIS INTERCEPTOR UPSTREAM END OF FLUME Page 3 of 4

Serial No.10-025 Docket 50-350 ENCLOSURE I-4 (RAI F.19.C.XIV) PHOTOS OF FLUME DRAIN DOWN FIBROUS AND PARTICULATE DEBRIS Page 4 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE J (RAI F. 19.C.XV) CHEMICAL CONCENTRATION WORKSHEETS Test 3 - Design Basis Chemical Batching Volumes ATTACHMENT 3 - C Concentration Calculation I Batch Sizing &Estimated PTO's to Complete TDI.6056.02 Rev 0 los rIla Cft11s* W-

• Iw

'Pape I Wiiu. L-W M I I.. H o-I PewvFun PUMP?L.W RAS *STARTUPt P l.WF~iai Ill' i ulh a t 4r) loR ied.. leo(1w) qg9l) (Cls) Cyc-sl..c)FTC (~~p Fler T01-00241-02L. 0.305 40. E23010 30.15 8 2.01a.44 0305 581.58 14.- 20.35 Alternael Test Water Level' 3.--

3. 0.305 0.00 8.70 0.70 0.0 0 00C 0.00 0.00 0.00 Scaled QtY Chem~cal DebrisConcenrtrations Ukm GI& atI te ortt) tfla"tpsP w~ URA 7

Chemiesl Durrip UipA~declfor Solusbility %L Chemnical"uiUpto Slimnst. Nag Fiber %L m.%woF=

Soxliur AkoarinmrS~tlcat. maitbrit 12.51 0.00 0.3 2%WCAP Surrogate - JU00 Alicmnwn Oxyltyrosre tin= lbi 0.00 0.21 WGAP Suirogsace- A40054 Casial Pohoptwt max bit 2A ILI9 WCAP Swiogte.ps Caictwn Phntcsiae Total WCAP Surroaalto Debris GAS0 0.113

[7ZJ-vy. bct Y.. W61. no, Aill.ted Q&-,dov Solos I&-I _____________________

Qviolyne Phosphtet 0.010 CadPWO COCOOwo 0.00000 lb a 0.00 10.00 0.00 0.00 0 0.00 Totals 12.51 0.53 Tt",t C0000414 0,00046782 ia 0.09 10.03 0.02 50.75 748 0.03

1. 11 CakohlwleVelurrmi of ALOOII P~rmicillt.

to bs AsseailW Plums. 10.1 Gommn 38,153 208.0'. 333

,.r XRi o 11Ca.O4P0)

Atlor hil.o-irif

,lC.;Moret W. fet; AUCO 0.04%

01.10%

0-II 1 00.03

.000 0.On0 0.09 1 0.00 0.03 0.00 0.02 50.75 0 10.0601 O0.00 11,4M3 0. I Conversion of 9IM I lite Ic-I o" a I 9g0IIhm 1 gram 0.00M60 lb:11 1 tstr 0.264172 gA30nS therefore, I oil 0.005345 lbt I grlcw

~

g1 0.091 Me lbs 1glon 0.041727 its;Iallan

1. 4n ptoALOODlddo 0.11? 9610ALOOM.iie 0.0 U en t~tshte ALOON~ Cltemncal Pr~ee.ite Reansis 10.13 qultAWLo 1ALO I Tarigetlamo(ALOOi4 0.03 beAOhlut DA" lslmeLPJ.)

Toll~ws la 70ls.5e lw".0111 190.1 TWA@

42151 3835 422 A,*m~t T~ulseant.I) ¶.uolIntKo) 10.3 .6 0.04 Page 1 of 2

Serial No.10-025 Docket 50-305 ENCLOSURE J (RAI F.19.C.XV) CHEMICAL CONCENTRATION WORKSHEETS Test 9 - Supplemental Design Basis Chemical Batching Volumes ATTACHMENT S - Chenmical Concentration Calculation I Batch Sizing & Estimated PTOas to Complete for Test 9 TDI-605r&02 Rev I al ~e-siftII 10s"r Pag~e I PLMV Acm I~ i n-t 12r- I s'uuP FI.O4FATE Q STARr UIP PUMay (Fma(a (0'!1.w)

Per TID"028.2"j2] .0 ~

40.5 23,1 ~ 3;1 20.69 ID 11.44 036 81.59 14.8 299 Altetriate Test Waster LeOvel,,,,3 ,*,, .

flCi.

Ot, Ais -traaolcloos U184 b. i ft' or li (cV4I1 Oncantlt isml op ups Chml.1tsDumplip Andded tonSotonblllty  % .0 7.13%1 Chemdcal BuampUptoElimrinate OngFitne.  % &09% blva=fit Sodiwum Aluminutm Silica%0 ibmWA [SflCAPuncaw -Al001i A:lwnicm, QOO~lwdioI bra 0.43 WCAPSurrogate-A10COH Calcium PllOaphale moxlm w90LSLlb., Q, WOAPSurtagalo- Caklcum Phosphate Total WCAPSuffocate Oebarto 41.78 `1A8 bMe 041 V.. to poseat Ib A~nntedoueenjos 60am Yo Cacltio RarerPt ow.lCt Race1 &or 11O dwd Aug %t2ha.0C308 25¶DatchIotaivals Charwad to PTO watto glidoe8.0 0 1311Sotch tnlrdals Remain. .2 PTO lm .Kent A" ae 4 -"J JAWbIcam OXavidrOetdo Plata________

CektS~tsh2 2&0 Re.i.~

2si...Test CBS Chrdh P~n AWOWt, 0000088

ý R- Co.

0ICC0925 5Eal 0

018 ale

.AL.

0.08 8.04 8.8 748 1.08 lCalcium Ptbmhoshtta O 0 C b C000s0200 0t lbo-c 0.00ýw 0.00 0.00 0.00 0 00

~oaa 50 2 .2 1.9im.0008 0C20.1835 ba 0.r= 0.04876 748 01.88 M0.464 2.011.4 11al C tf*.ed Voahns of Al.OOt PmedPctlo to be Added to Flunno 20.3 ows 38,131 268.0

• 1.. 33.33% 1 20.00 I 12.43 "hOUrS For ftadtC.-asaioop - he 11OPcM ~nactP- - t1t

'*°l 100,00%

AlOWet C*o 0.004% :1.0898 1000 0.00 0,08 0,19 0.00 0.05805 0.04 0,00, 1 A20 10.00 1 Cosveralea oef"Otra I l*,or" to "lbs I gallon" I gram 0.0022 1l" I liter W.8.417 oaeltcn threfore. 1 /I = M.OWSft Im) gallon 11 gil 0 0.0818 IbB2gal.no DITFIo. G81Chac-2008-04; 11042 So)I a 08*4172 Ibolgollocm Well ass am £ Jeta Batch Volumesa NaAMA* 26.02 0 .. 10323% Gatctls

a '10.058 7905 A¢OOFI 0.00 0 IaiII aC~a4 .5 Ibm, 035 0.04 ia cal phALoluelmho CaC8000 01.0 0 Alia Bolchos Q 8311 0.00 bGi6i

• LQOO4 Clramnlccl PraciltOlte P201l69 20.28 GWWOAL0ON Targe Ibm of ALOOH 1.9 el ALOON . iq O1l1 20.28 Towas 834.70 78.70 a.44 2t 8 G O2n d A5to.2710 3 1 T0 10I .SO8 t 2D.26 5,27 1.69 Page 2 of 2

Serial No.10-025 Docket 50-305 ENCLOSURE K (RAI 20/21/22) VORTEX CALCULATION TDI-6008-07, REVISION 6 CALCULATION ATTACHED

.Pc I PERFORMANCE C;ONIRIACIING INC Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strairier) -

Kewaunee Power St 'ation Technical Document No. TDI-60108-07 Revi*

sion 6 CALCULATION COVER SHEET Calculation Number: TDI-6008-07 Technical Document Rev. No. 6 Addenda No.: N/A Calculation

Title:

Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

- Kewaunee Power Station Safety Related? YES Calculation Verification Method (Check One):

Z Design Review LI Alternate Calculation 0 Qualification Testing Scope of Revision:

Revision to address and incorporate KPS comments.

Revision 6, pages: All Date: /(/*. 0 Date: a// 12-010/a Date: / o TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc PagelIof 32 1

OPCI PERFORMANCL

(')ONIRACIING INC Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer) -

Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 CALCULATION VERIFICATION CHECKLIST Calculation

Title:

Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer) - Kewaunee Power Station Revision: 6 CHECKLIST Yes No n/a

1. Were inputs correctly selected and incorporated? Z El [I

2. Are assumptions adequately described and reasonable? 0 El El

3. Are the appropriate quality and quality assurance requirements specified? Z El El

4. Are the applicable codes, standards and regulatory requirements identified and 0 El El met?

5. Have applicable construction and operating experience been considered? z [E El

6. Have the design interface requirements been satisfied? 0 El El

7. Was an appropriate design method used? 0 0 El

8. Is the output reasonable compared to input? E E] 0

9. Are specified parts, equipment, and processes suitable for the required application? El El Z

10. Are the specified materials compatible with design environmental conditions? El El 0

11. Have adequate maintenance features and requirements been specified? El El 0

12. Are accessibility and other design provision adequate? El E] 0

13. Has adequate accessibility been provided to perform the in-service inspection? El El 0

14. Has the design properly considered radiation exposure? El El Z

15. Are the acceptance criteria incorporated in the design documents sufficient to allow 0 El El verification?

16. Have adequate pre-operational and subsequent periodic test requirements been El El 0 specified?

17. Are adequate handling storage, cleaning and shipping requirements specified? El El 0

18. Are adequate identification requirements specified? EZ El N

19. Are requirements for record preparation, review, approval, retention, etc.,

adequately specified? I El El 0 Has the appropriate Calculation Guideline Verification Checklist been reviewed and 20.

signed?

3060-3 Revision 3 Verified b' TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 2of 32 1

Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer) -

71PCI PERFORMANCE Kewaunee Power Station Technical Document No. TDI-6008-07 CONIRACIING INC Revision 61 TABLE OF CONTENTS CALCULATION COVER SHEET CALCULATION VERIFICATION CHECKLIST TABLE OF CONTENTS 1.0 Purpose and Summary Results 2.0 Definitions and Terminology 3.0 Facts and Assumptions 4.0 Design Inputs 5.0 Methodology 6.0 Acceptance Criteria 7.0 Calculation(s) 7.1 Vortex 7.2 Air Ingestion 7.3 Void Fraction 8.0 Conclusions 9.0 References 10.0 Drawings ATTACHMENTS Attachment 1 Flashing & Gas Evolution Analysis TABLES Table 1 Results Summary Table 2 Calculation Results Originated By:  : _ Date: / /,

TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 3 of 32

MPCI PERFORMANCE CONIRACIING INC Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer) -

Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 1.0 Purpose and Summary Results The US Nuclear Regulatory Commission (USNRC) in generic safety issue (GSI) 191 identified it was possible that debris in PWR containments could be transported to the emergency core cooling system (ECCS) sump(s) following a main steam line break (MSLB) and/or a loss of coolant accident (LOCA). It was further determined that the transported debris could possibly clog the sump screens/strainers and impair the flow of water, thus directly affecting the resultant operability of the various ECCS pumps and the containment spray (CS) system pumps, and their ability to meet their design basis function(s). In order to address and resolve the various issues identified by the USNRC in GSI-191, utilities have implemented a program of replacing the existing ECCS sump screens or strainers with new and improved designs.

Dominion Energy Kewaunee, Inc. (DEK) entered into a contract with Performance Contracting, Inc. (PCI) to address and resolve the specific issues associated with USNRC GSI-191 for the Kewaunee Power Station (Kewaunee).

The primary objective of the contract was for PCI to provide a qualified Sure-FlowR Suction Strainer that has been specifically designed for Kewaunee in order to address and resolve the NRC GSI-191 ECCS sump clogging issue.

PCI has prepared a Qualification Report specifically for the subject strainer. The Qualification Report is a compilation of the various documents and calculations that support the strainer qualification.

As part of the Kewaunee Qualification Report, PCI has performed a number of hydraulic calculations in support of the replacement Sure-Flow Suction Strainer.

This calculation TDI-6008-07, Vortex, Air Ingestion & Void Fraction - Kewaunee Power Station is one of a number of hydraulic calculations that specifically supports the design and qualification of the subject strainer.

This calculation addresses the various issues associated with the separate but related issues associated with vortex, air ingestion, and void fraction as they relate to the sump and strainer assembly that has been designed specifically for Kewaunee.

Kewaunee has one recirculation strainer assembly that feeds a common suction sump. The Kewaunee 'A' or 'B' train ECCS and the CS system are supplied by the recirculation strainer. The horizontally oriented recirculation strainer assembly is comprised of fourteen (14) modules each made up of six (6) strainer disks for a total strainer area of 768.7 ft2 . Flow leaves the strainer and enters a combination of pipe and fittings before discharging into the sump pit. A maintenance hatch (employing two (2) disks) for the sump also provides for Originated By: _________________ Date: / */

TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 4 of 32 1

Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer) -

Kewaunee Power Station PERFORMANCE Technical Document No. TDI-6008-07 CONIACI ING INC Revision 6 water entry into the sump at a lower elevation. However, the maintenance hatch is not credited as a recirculation system strainer and it is not included in the PCI calculations for the recirculation strainer. PCI drawings [Drawings 10.1 - 10.8, inclusive] provide details of the subject configuration.

The results of the calculation are provided in Table 1. The calculation utilizes the Acceptance Criteria established in both Kewaunee and USNRC documents with respect to PWR sump performance to specifically evaluate the Kewaunee Sure-Flow Suction Strainer assembly.

Table 1 - Results Summary Issue Acceptance Criteria Results USNRC Kewaunee Vortex No vortex No detrimental ACCEPTABLE - Vortex formation is effects on ECCS precluded by the PCI Sure-Flow Suction

& CS pumps Strainer design and configuration Air 0% or <2% <2% ACCEPTABLE - Air ingestion will not occur Ingestion since there is no vortex formation associated with the PCI Sure-Flow Suction Strainer design and configuration Void <3% Flashing ACCEPTABLE - Voids will not occur at the Fraction prevented down strainer (calculation indicates <0%) based stream of the on Kewaunee specified post-LOCA strainer pressure and temperature parameters. In addition, the calculation also concludes that voids occurring in the Sure-Flow Suction Strainer assembly will have collapsed by the time the sump water leaves the strainer assembly and discharge piping, and before leaving the KPS containment sump.

Attachment 1, Flashing & Gas Evolution Analysis provides an evaluation of the subject issues. It was determined that there are no flashing or gas evolution issues for KPS.

It was concluded that this calculation, an integral portion of the Qualification Report completely supports the qualification, installation, and use of the PCI Sure-Flow Suction Strainer for DEK's Kewaunee Power Station without any issues or reservations.

Originated By: iv' 1-1 9AIA TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Date:

Page 5 of 32

I C Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer) -

PERFORMANCE CONIRACIING INC ON P01 PC IKewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 2.0 Definitions & Terminology The following Definitions & Terminology are defined and described as they are utilized in this calculation.

Sure-Flow Suction Strainer - Strainer developed and designed by Performance Contracting, Inc. that employs Sure-Flow technology to reduce inlet approach velocity.

Emergency Core Cooling System (ECCS) - The ECCS is a combination of pumps, piping, and heat exchangers that can be combined in various configurations to provide either safety injection or decay heat cooling to the reactor.

Kewaunee Power Station - also known as Kewaunee and KPS.

Main Steam Line Break - also known as MSLB. A MSLB is not a LOCA.

Containment Spray System - also known as CSS or CS. System is utilized to address either a MSLB or a LOCA.

Loss-Of-Coolant-Accident - also known as a LOCA. A LOCA is the result of a pipe break or inadvertent leak that results in the discharge of primary reactor coolant from the normal nuclear steam supply system (NSSS) boundary. A LOCA can be classified as a large break LOCA (LBLOCA) or a small break LOCA (SBLOCA). Classification is directly dependent upon the nominal size of the affected pipe that is associated with the LOCA.

3.0 Facts and Assumptions The following Facts (designated as [F]) & Assumptions (designated as [A]) were utilized in the preparation of this calculation.

3.1 Pressure of 39.3989 psia and temperature of 214.7111 OF were provided by Kewaunee as design input in order to determine head-loss, vortex, air ingestion, and void fraction in accordance with various USNRC guidance documents [Reference 9.18] [F].

3.2 A flow velocity of 0.0056 fps would be characteristic of the Kewaunee strainer, through a debris bed consisting of fibers and particulate is 100%

viscous flow. Accordingly, the head loss is linearly proportional to dynamic viscosity [A].

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Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 3.3 A scale strainer, which is designed to maintain the same approach velocity as the full scale production strainer, can accurately simulate the performance of the full scale production strainer so long as the same scaling factor is used for strainer area, water flow rate, and debris quantities. The scaling factor is defined as ratio of the surface area of the scale strainer and the surface area of the full scale production strainer [A].

3.4 The head loss resulting from flow through a fiber - particulate debris bed at the approach velocity for the Kewaunee strainer (0.0056 ft/s)

[Reference 9.10], is 100% viscous flow, as opposed to inertial flow. As viscous flow, head loss is linearly dependent on the product of viscosity and velocity. Therefore, to adjust the measured head loss across a debris bed with colder water, a ratio of water viscosities, between the warmer specified post-LOCA water temperature and the colder test temperature, can be multiplied by the measured head loss to obtain a prediction of the head loss with water at the specified post-LOCA temperature [A].

4.0 Design Inputs The following combination of DEK and PCI Design Inputs were utilized in the preparation of this calculation.

4.1 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Technical Specification for Containment Sump Strainers, No. K-4890, Revision 0

[Reference 9.1]. This document provides design input associated with strainer flow rate, water temperature, and the maximum allowable head loss.

4.2 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), DIT No. PCI-06-008, Replace Containment Recirculation Sump B Screens, dated 4/18/06 [Reference 9.8]. This document provides specific information for calculating the void fraction for the new strainer.

4.3 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), DIT No. PCI-06-011, Replace Containment Recirculation Sump B Screens, dated 4/21/06 [Reference 9.3]. This document provides specific information for calculating the void fraction for the new strainer.

4.4 Performance Contracting, Inc. (PCI) Calculation TDI-6008-02, SFS Surface Area, Flow and Volume Calculation, Revision 1 [Reference 9.16].

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NAF'C PERFORMANCE I .Kewaunee Power Station Technical Document No. TDI-6008-07 CONIRACTING INC Revision 6 This document provides relevant dimensions and other information specifically associated with the Kewaunee strainer.

4. 5 PCI Calculation TDI-6008-05, Clean Head Loss (ECCS Recirculation Strainer)- Kewaunee Power Station, Revision 4 [Reference 9.10]. This document provides the head loss associated with the "clean" Kewaunee strainer and attached pipe and fittings.

4.6 PCI Calculation TDI-6008-06, Total Head Loss (ECCS Recirculation Strainer)- Kewaunee Power Station, Revision 8 [Reference 9.9]. This document provides the total head loss associated with the Kewaunee strainer and attached pipe and fittings.

4.7 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), DIT No. PCI-06-015, Replace ECCS Recirculation Strainer, dated 7/7/06 [Reference 9.17]. This document provides specific information for calculating the void fraction for the new strainer.

4.8 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), DIT No. PCI-06-016, Replace ECCS Recirculation Strainer, dated 7/12/06 [Reference 9.18]. This document provides specific information for calculating the void fraction for the new strainer.

4.9 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), GSI Chem-2008-04, Revision 2, Chemical Effects Testing, dated 7/16/08 [Reference 9.20]. Document provides revision of Kewaunee debris allocation and ECCS flow rates.

4.10 AREVA Engineering Information Record, Document Identification No. 66-9089247, Kewaunee Test Report for ECCS StrainerPerformance Testing, Revision 0, September, 2008 [Reference 9.4]. This document provides the method and value of the tested debris head loss and the mechanism of adjusting the tested debris head loss to the specified post-LOCA water temperature.

4.11 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), DIT No. PCI-09-001, GSI-191 Resolution, dated 9/24/09 [Reference 9.21]. This document provides specific information regarding the post-LOCA containment water level for calculating flashing and determining gas evolution for the new strainer.

Originated By: (2 Date: /6// ,/

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Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 4.12 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, EOP Setpoint Calculation Wide Range Containment Sump Level Versus Available RWST Volume, C10984, Revision 1, Addendum A [Reference 9.22]. This document provides specific information regarding the post-LOCA containment water level for calculating flashing and determining gas evolution for the new strainer.

5.0 Methodology PCI utilized classical standard hydraulic principles and equations to address the subject issues. PCI recognizes that if it is determined that one of the issues cannot occur and/or can be prevented, then one or more of the other issues cannot occur (e.g., if a vortex is not predicted by calculation then there should be no air ingestion). However, PCI has conservatively assumed that each issue is separate, and each issue will be addressed on its own merits.

6.0 Acceptance Criteria This specific calculation addresses three (3) separate but related issues - vortex, air ingestion and void fraction. Accordingly, each issue has it own separate acceptance criterion. The final overall acceptance criterion is that the Kewaunee ECCS pumps have adequate NPSH margin under all postulated post-LOCA conditions.

Vortex The USNRC in RG 1.82 Revision 3 [Reference 9.6] has indicated that air ingestion can lead to ECCS pump degradation and/or failure. A vortex is a potential source of air ingestion. A vortex can be prevented due to various combinations of sump configuration and the addition of vortex suppressors in the sump.

The Acceptance Criteria for vortex is the complete elimination of occurrence.

Air Ingestion RG 1.82 Revision 3 [Reference 9.6] states that air ingestion can lead to ECCS pump degradation and/or failure if air ingestion is > 3%. Accordingly, the USNRC has recommended a limit of 2% by volume on sump air ingestion. In addition, the USNRC has also recommended that even with air ingestion levels at 2% or less, NPSH can still be affected. The USNRC has further recommended that if air ingestion is indicated, that the NPSH be corrected from the pump curves.

The Acceptance Criteria for air ingestion is < 2%.

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VA PCtI PERFORMANCE Kewaunee Power Station Technical Document No. TDI-6008-07 CONIRACTING INC Revision 6 I Void Fraction USNRC GS1-191 SE [Reference 9.5] has indicated that ECCS pumps can experience cavitation problems when inlet void fraction exceeds approximately 3%.

The Acceptance Criteria for void fraction is <3% in conjunction with an acceptable sump pool temperature operating range as specified in.Attachment V-1 of [Reference 9.7].

7.0 Calculation(s)

In order to address and determine the acceptability and/or issues potentially associated with the three (3) separate but related issues of vortex, air ingestion and void fraction, a separate analysis of each issue was performed.

7.1 Vortex The Kewaunee specification [Reference 9.1], specifically section 3.6.9 addresses strainer vortex, but does not provide limitations on the new strainer design that specifically prohibits the formation of a vortex (i.e., no vortex allowed). Accordingly, PCI has utilized the guidance of USNRC RG 1.82, Revision 3 [Reference 9.4] to address the vortex issue for the Kewaunee strainer.

In [Reference 9.6], the USNRC provided generic guidance with respect to PWR sump performance, sump design, and vortex suppression. The subject reference can be utilized as a means of assessing sump hydraulic performance, specifically the issues associated with a potential vortex in the sump.

The Kewaunee sump pit is approximately 8'-6" (W) x 8'-6" (L) x 7'-9" (D),

including the height of the curb around the sump. The opening into the sump is approximately 2'-8" (W) x 8'-6" (L). The majority of the sump is covered by the Reactor Building floor slab located at elevation 592'-0".

The opening into the sump was previously covered by a plate on which were mounted, two (2) "conical-shaped" vertically oriented strainer elements that were made of Johnson screen [Reference 9.1].

Since the Kewaunee sump and ECCS pump inlets were modified by the addition of the PCI Sure-Flow suction strainer, the guidance offered by the USNRC in [Reference 9.6] is not entirely or specifically applicable.

However, the guidance does provide some information that can be utilized Originated By: Date: //I.

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E PC IKewau nee Power Station PERFORMANCE CONIRACIING INC Technical Document No. TDI-6008-07 Revision 6 in the assessment of the revised Kewaunee sump and strainer configuration with regard to vortex issues.

The "revised" Kewaunee sump and strainer configuration utilizes a horizontally oriented, fourteen (14) module PCI Sure-Flow suction strainer that discharges through attached pipe and fittings to a cover plate mounted directly on the sump. In addition to the suction strainer, a removable maintenance hatch was installed containing a two-disk vertically oriented PCI Sure-Flow suction strainer [Drawing 10.1 - 10.8, inclusive].

The PCI Sure-Flow suction strainer and removable maintenance hatch will be separately analyzed and addressed with respect to vortex issues.

PCI Sure-Flow Suction Strainer The PCI Sure-Flow suction strainer for Kewaunee is comprised of fourteen (14) horizontally oriented modules each containing six (6) disks.

The disks are a nominal 5/8" thick and are separated 1" from each adjacent disk. The interior of the disks contain rectangular wire stiffeners for support, configured as a "sandwich" made up of three (3) layers of wires - 7 gauge, 8 gauge, and 7 gauge. The disks are completely covered with perforated plate having 0.066" holes. The end disk of a module is separated approximately 5" from the end disk of the adjacent module.

The 5" space between adjacent modules is covered with a solid sheet metal "collar." Each of the modules has cross-bracing on the two exterior vertical surfaces of each module.

Based on the design configuration of the Kewaunee strainer assembly, the largest opening for water to enter into the sump is through the perforated plate 0.066" holes. The size of the perforated plate holes by themselves would preclude the formation of a vortex. However, in the unlikely event that a series of "mini-vortices" combined in the interior of a disk to form a vortex, the combination of the wire stiffener "sandwich" and the small openings and passages that direct the flow of water to the strainer core tube would further preclude the formation of a vortex in either the core tube or the sump.

The USNRC in [Reference 9.6], specifically Table A-6 guidance is provided with regard to vortex suppressors. The table specifies that standard 1.5" or deeper floor grating or its equivalent has the capability to suppress the formation of a vortex with at least 6" of submergence.

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Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 The design configuration of the PCI Sure-Flow suction strainer for Kewaunee due to the close spacing of various strainer components and the small hole size of the perforated plate meets and/or exceeds the guidance found in Table A-6. The Kewaunee strainer does not meet the 6" submergence requirement. The configuration for Kewaunee results in an actual submergence of 3" (2" utilized for calculations) to the top of the strainer assembly. However, there is a submergence level of approximately 11" to the top of the core tube. In addition the water flow would have to pass through more than 8" of combined perforated plate, wire stiffener "sandwiches", and cross-bracing which would further preclude the formation of a vortex.

The USNRC carried out a number of tests regarding vortex suppressors at the Alden Research Laboratory (ARL) to arrive at the information summarized in Table A-6 of [Reference 9.6]. The PCI Sure-Flow suction strainer prototype for Kewaunee was also tested at ARL under various conditions. During the original testing of the Kewaunee strainer even when partially uncovered, did not exhibit any characteristics associated with a vortex or vortex development. The recent Kewaunee strainer testing at ARL in August 2008 indicated that there was no indication or observation of vortex initiation or formation [Reference 9.4].

It can therefore be concluded that the configuration of the Kewaunee Sure-Flow suction strainer will prevent the formation of vortex development.

Removable Maintenance Hatch The Removable Maintenance Hatch for Kewaunee is comprised of a single vertically oriented module containing two (2) disks. The disks are a nominal 5/8" thick and are separated 1" from each other. The interior of the disks contain a circular "spider" rectangular wire stiffeners for support, configured as a "sandwich" made up of three (3) layers of wires - 7 gauge, 8 gauge, and 7 gauge. The disks are completely covered with perforated plate having 0.066" holes. An external radial debris stop with integral cross-bracing assists in both the structural stability of the two strainer disks as well as to preclude the introduction of large debris to the disks.

Based on the fact that the subject strainer disks, cross bracing and the addition of the "spider" stiffener are of similar design configuration as that of the Kewaunee strainer assembly, and based upon its lower sump elevation and thus greater submergence than the ECCS Recirculation Strainer it can be concluded that the configuration of the Kewaunee Originated Ewj.

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Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 Removable Maintenance Hatch strainer will prevent the formation of vortex development.

7.2 Air Ingestion The Kewaunee specification [Reference 9.1], sections 3.4.1.10 and 3.4.1.13 address vortex issues, and section 3.4.1.13 specifically requires that the new strainer have a design that limits air ingestion to <2%. This requirement is in accordance with USNRC RG 1.82, Revision 3

[Reference 9.6]. Appendix A and Table A-1 of [Reference 9.6] indicate that sump performance specifically related to air ingestion is a strong function of the Froude Number, Fr. By limiting the Froude Number to a maximum of 0.25, air ingestion can be maintained to <2%.

The flow of post-LOCA water from a piping system associated with a LBLOCA or SBLOCA, or a CS initiation associated with a LOCA collects in the lower areas of the containment and eventually migrates to the ECCS sump. The flow can be considered to be and is classified as open channel flow. For open channel flow, the Froude Number, Fr, is defined as follows

[Reference 9.11].

Fr = V I (g x s)112 Where V = the velocity of water exiting the core tube. For Kewaunee Vex = 2.453 ft/s [Reference 9.10].

S = the ratio of the cross-sectional area of the PCI Sure-FlowTM suction strainer core tube, Ae,, and the equivalent diameter of the core tube smallest orifice, Dhole , ft.

2 g = gravitational constant, 32.2 ft/s The most conservative value that can be utilized for s is the case of the core tube cross-sectional area and the smallest hole in the core tube.

From the Kewaunee Clean Head Loss report [Reference 9.10], A.x =

1.744 ft2. The Kewaunee Core Tube Design report [Reference 9.19]

indicates that the smallest calculated hole / slot area, Ahole, 1B = 0.720 in2 or 0.0050 ft2 ,

Therefore, the equivalent diameter of the smallest core tube hole can be calculated as follows.

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FAP(9I Kewaunee Power Station PERFORMANCE C(-)N IRAGiIIINGJ,1INC Technical Document No. TDI-6008-07 CON-A: N IC Revision 6 Dhole, 1A = (4 Ahole, IB I Tr )112

= (4 x 0.0050 / Tr )112

= 0.0798 ft The value s can be calculated as follows.

s =Aex / Dhole, IB

=1.744 / 0.0798

= 21.8546 Accordingly, value of Fr can be calculated as follows.

2 Fr = V I (g x s)11 Fr = 2.453 / (32.2 x 21.8546) 1/2

= 2.453 / 26.5277

= 0.0925 The calculated Froude Number for the Kewaunee PCI Sure-Flow suction strainer is substantially smaller than the USNRC guidance of 0.25 found in

[Reference 9.6]. Therefore due to the combination of a low Froude Number and lack of an air entrainment mechanism (i.e., vortex formation) in conjunction with the complete submergence of the strainer, air ingestion is not expected to occur.

7.3 Void Fraction The Kewaunee specification [Reference 9.1], does not specifically address the issue of Void Fraction. Accordingly, PCI has utilized the guidance of USNRC documents [Reference 9.5, 9.6. 9.7, and 9.15] to address the void fraction issue for the Kewaunee strainer.

Although it is asserted in various regulatory documents that void formation is directly related to air ingestion, this is not correct. Void formation is the result of the pressure of a fluid being reduced below the saturation Originated By: ____ ____ Date: /

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PERFORMANCE P

I Kewaunee Power Station Technical Document No. TDI-6008-07 CONIIRACIING INC Revision 6 pressure with the resulting voids being formed by the flashing of the liquid phase. Air does not need to be present to create significant voiding.

PCI has evaluated the issue of Void Fraction by the use of conventional hydraulic and fluid flow calculations to determine the Kewaunee Void Fraction.

Conventional Calculation Methodology Kewaunee [Reference 9.18] defined the containment post-LOCA water temperature as being 214.7110 F. A corresponding containment pressure of 39.3989 psia was provided [Reference 9.18]. The measured strainer Design Basis debris head loss was 1.1034 feet of water [Reference 9.9]

and the Supplemental Design Basis debris head loss was 3.2860 feet of water [Reference 9.9], based on and adjusted for the Kewaunee Design Basis temperature of 65 OF. By applying a temperature viscosity adjustment [Reference 9.9] to the strainer debris head losses (i.e., Design Basis and Supplemental Design Basis) from the Kewaunee Design Basis water temperature of 65 OF to the specified post-LOCA condition of 214.711 OF, the maximum expected debris head losses (i.e., Design Basis and Supplemental Design Basis) at the subject post-LOCA water temperature can be determined.

Design Basis HLTA = HLDL,C (IJST / P Tr)

Where HLDL,C= corrected, Design Basis Debris Loaded Head Loss, 1.1034 ft of water PST = dynamic viscosity at the post-LOCA specified temperature of 214.711 °F

= 0.000186426 lb/ft-s PTT = dynamic viscosity at the Kewaunee Design Basis temperature of 65 OF

= 0.000701778 lb/ft-s HLTA = temperature adjusted debris head loss, ft

= 1.1034 ft (0.000186426/0.000701778)

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Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6

= 1.1034 ft x 0.2657

= 0.2932 ft of water, or

= 0.1271 psi Supplemental Design Basis HLTA = HLDL,C (liST I P TT)

Where HLDL,C= corrected, Supplemental Design Basis Debris Loaded Head Loss, 3.2860 ft of water PiST = dynamic viscosity at the post-LOCA specified temperature of 214.711 °F

= 0.000186426 lb/ft-s lirr = dynamic viscosity at the Kewaunee Design Basis temperature of 65 OF

= 0.000701778 lb/ft-s HLTA = temperature adjusted debris head loss, ft

= 3.2860 ft (0.000186426 / 0.000701778)

= 3.2860 ft x 0.2657

= 0.8731 ft of water, or

= 0.3785 psi Subtracting the calculated head losses for the Design Basis and Supplemental Design Basis (i.e., 0.1271 and 0.3785 psi, respectively) from the Kewaunee specified containment post-LOCA pressure of 39.3989 psia [Reference 9.1 and 9.18] results in respective pressures of 39.2718 and 39.0204 psia associated with the downstream side of the strainer debris bed. The water vapor pressure at 214.7111 °F is 15.509 psi. This is 23.7628 and 23.5114 psi, respectively less than the calculated downstream strainer debris bed pressures of 39.2718 and 39.0204 psia.

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Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 Therefore boiling and flashing of the sump water will not occur across the strainer debris bed and would not create a > 3% void fraction.

Because "flashing" would not occur at the strainer based on the Kewaunee specified temperature and pressure parameters within the post-LOCA containment, it is highly unlikely that "flashing" or a void fraction > 3% would be present at the outlet of the strainer piping as the strainer discharge flow enters the containment sump.

This conclusion is based on the following analysis.

Given [Reference 9.16]:

Available submergence (total water depth in Kewaunee containment @ centerline of sump suction): 9.175' (110.1")

Worse-Case Strainer Head Loss (i.e., Supplemental Design Basis): 0.8731' Difference: 8.3019' (3.5991 psi)

It was previously determined that a minimum pressure of 0.3785 psi (i.e.,

Supplemental Design Basis Head Loss) is required to prevent "flashing" and subsequent void fraction formation. Accordingly, it can be concluded that any voids caused by "flashing" of the water in the strainer would have collapsed by the time the water leaves the strainer assembly and discharge piping. This is based on the fact that the containment water head is at least 8.3019 feet greater than saturation (i.e., 3.5991 psi >

0.3785 psi). Therefore it can be concluded that there will be 0% void fraction associated with the strainer discharge flow before it leaves the Kewaunee containment sump under the post-LOCA containment pressure and temperature parameters of 39.3989 psia and 214.7111 OF, respectively.

8.0 Conclusions The result of this calculation, specifically the acceptability of the issues associated with vortex, air ingestion, and void fraction are summarized in Table

2. Flashing and gas evolution are addressed in Attachment 1.

It was concluded that the subject issues have been addressed for Kewaunee and the results indicate that there are no problems. This specific calculation Originated By: *'/ .*k, 44 Date:

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Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 61 completely supports the qualification, installation, and use of the PCI Sure-Flow Suction Strainer for DEK's Kewaunee Power Station without any issues or reservations.

Originated By: d/ Wý Date: / /

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- Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 Table 2 - Calculation Results Issue Acceptance Criteria Results Comments USNRC Kewaunee Vortex None No ACCEPTABLE Results applicable to the Kewaunee Sure-Flow detrimental strainer.

(Ref: Rev, 1.82. RG effects on No Vortex - vortex formation is

3) ECCS & precluded by the PCI Sure-Flow

3) pums& Suction Strainer design and CS pumps configuration.

Air Ingestion 0% or <2% ACCEPTABLE Per RG 1.82, Revision 3, if air ingestion is > 0%,

<2% Air Ingestion could occur- calculation the pump NPSH must be corrected by the (Ref: RG indicates > 0% but < 2%. However, relationship, NPSHrequired (fcp<2%) = NPSH 1.82, Rev. since it has been determined that vortex required(liquid)X 03, where P3=1 + 0.50Ocp and ccp is the

3) formation will not occur then it can be air ingestion rate (in percent by volume) at the reasonably concluded that air ingestion pump inlet flange.

will also not occur.

Void <3% Flashing ACCEPTABLE Conventional calculation methodology indicates Fraction (Ref- prevented Voids will not occur at the strainer that a void fraction of >0% will not occur at the USNRC down (calculation indicates <0%) based on strainer.

GS1-191 stream of th (aclto niae 0)bsdo thestreaine GSafety1 KPS specified post-LOCA pressure and Safety strainer Evaluation temperature parameters. In addition, (SE)) the calculation also concludes that voids occurring in the strainer will have collapsed by the time the sump water leaves the strainer assembly and discharge piping, and before leaving the KPS containment sump.

(K7r~/

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Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

- Kewaunee Power Station PERFORMANCE Technical Document No. TDI-6008-07 CONIRACIING INC Revision 6 9.0 References 9.1 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Technical Specification for Containment Sump Strainers,No. K-4890, Revision 0 9.2 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), DIT No. PCI-06-008, Replace Containment Recirculation Sump B Screens, dated 4/18/06 9.3 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), DIT No. PCI-06-01 1, Replace Containment Recirculation Sump B Screens, dated 4/21/06.

9.4 AREVA Engineering Information Record, Document Identification No. 66-9089247, Kewaunee Test Report for ECCS StrainerPerformance Testing, Revision 0, September, 2008 9.5 U.S. Nuclear Regulatory Commission, Safety Evaluation, Pressurized Water Reactor Sump Performance Evaluation Methodology, Guidance Report of the Nuclear Energy Institute (NEI), GSI-191 SE, Revision 0, dated December 6, 2004 9.6 U.S. Nuclear Regulatory Commission, Regulatory Guide 1.82, Water Sources for Long-Term Recirculation Cooling Following a Loss-of-Coolant Accident, Revision 3, dated November 2003 9.7 U.S. Nuclear Regulatory Commission, GSI-191 SE, Attachment V-i, NUREG/CR-6224 Head Loss Temperature Assessment. Revision 0, December 2004 9.8 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), DIT No. PCI-06-008, Replace Containment Recirculation Sump B Screens, dated 4/18/06.

9.9 PCI Calculation TDI-6008-06, Total Head Loss (ECCS Recirculation Strainer)- Kewaunee Power Station, Revision 8 9.10 PCI, Technical Document Number, TDI-6008-05, Clean Head Loss (ECCS Recirculation Strainer)- Kewaunee Power Station, Revision 4 Originated By: Date: / ,,'

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MPC!

PERFORMANCE CONIRACIING INC Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

- Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 9.11 Urquhart, Leonard C., Civil Engineering Handbook, Fourth Edition, McGraw-Hill Book Company, Inc., 1959 9.12 DELETED - Not Used 9.13 Nazeer, Ahmed, Fluid Mechanics, Engineering Press, Inc., 1987 9.14 NEI 04-07, Pressurized Water Reactor Sump Performance Evaluation Methodology, Rev. 0, December, 2004 9.15 DELETED- Not Used 9.16 PCI, Technical Document Number, TDI-6008-02, SFS Surface Area, Flow and Volume Calculation,Revision 1 9.17 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), DIT No. PCI-06-015, Replace ECCS Recirculation Strainer,dated 7/7/06 9.18 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), DIT No. PCI-06-016, Replace ECCS Recirculation Strainer,dated 7/12/06 9.19 PCI, Technical Document Number, TDI-6008-03, Core Tube Design -

Kewaunee Power Station, Revision 2 9.20 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), GSI Chem-2008-04, Revision 2, Chemical Effects Testing, dated 7/16/08 9.21 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, Design Information Transmittal (DIT), DIT No. PCI-09-001, GSI-191 Resolution, dated 9/24/09 9.22 Dominion Energy Kewaunee, Inc., Kewaunee Power Station, EOP Setpoint Calculation Wide Range Containment Sump Level Versus Available RWST Volume, C10984, Revision 1, Addendum A 9.23 Westinghouse Electric Company, Evaluation of Post-Accident Chemical Effects in Containment Sump Fluids to Support GSI-191, WCAP-16530-NP, Revision 0, February 2006 Originated By: ftz Date: /

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EPCI PERFORMANCE CONIRACIING INC Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

- Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 10.0 Drawings 10.1 SFS-KW-GA-01, Revision 3, Kewaunee Power Station, Sure-Flow Strainer,General Arrangement 10.2 SFS-KW-GA-02, Revision 6, Kewaunee Power Station, Sure Flow Strainer,StrainerA 10.3 SFS-KW-GA-03, Revision 5, Kewaunee Power Station, Sure Flow StrainerSump Cover and Piping Layout 10.4 SFS-KW-PA-7100, Revision 5, Kewaunee Power Station, Sure Flow StrainerModule Assembly 10.5 SFS-KW-PA-7103, Revision 4, Kewaunee Power Station, Sure-Flow Strainer,Maintenance Hatch 10.6 SFS-KW-PA-7161, Revision 4, Kewaunee Power Station, Sure Flow Strainer Pipe 1 10.7 SFS-KW-PA-7162, Revision 3, Kewaunee Power Station, Sure Flow StrainerPipe 2 10.8 SFS-KW-PA-7163, Revision 3, Kewaunee Power Station, Sure Flow StrainerPipe 3 Originated By: Date: /16/ C17 TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 22 of 32 I

Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

.Pc PERFORMANCE CON IRACi INr I

N

- Kewaunee Power Station Technical Document No. TDI-6008-07 6

NRevision ATTACHMENT I - Flashing & Gas Evolution Analysis The application of either static water head and/or post-LOCA containment over-pressure for the Kewaunee Power Station (KPS) strainer will result in no flashing based on the very conservative use of the KPS strainer head loss associated with the 65 OF Design Basis temperature (i.e., post-LOCA long-term cooling). In addition the analysis of gas evolution downstream of the strainer indicates that it is significantly less than 0.5% which is also less than the allowable 3% value stated in RG 1.82, Revision 3.

Flashing (boiling) of the post-LOCA containment fluid would occur if the post-LOCA containment pressure was reduced to a value below the corresponding fluid temperature (saturation temperature), or if the head loss associated with the strainer and debris bed is such that the post-LOCA containment fluid passing through the strainer and debris bed is reduced to a value below the corresponding fluid temperature (saturation temperature). The flashing post-LOCA containment fluid would release both condensable and non-condensable gases (gas evolution). If the gases are released in a manner such that they are 'captured' by the strainer discharge fluid flow, they would cumulatively result in potential voids (void fraction) that could be transported to the ECCS/CSS pumps.

In order to address the associated but separate issues of flashing and gas evolution (de-aeration) in a logical and concise manner, the large break loss-of-coolant accident (i.e., LBLOCA) will be addressed to determine and address the issue of flashing including minimum margin to flashing at the strainer debris bed and within the KPS sump. In addition, an evaluation of gas evolution (de-aeration) downstream of the strainer (void fraction) that could reach the ECCS/CSS pump suctions is also provided.

BACKGROUND Large Break Loss-of-Coolant Accident (LBLOCA)

The maximum ECCS/CSS recirculation flow is based on the KPS Design Basis conditions of Case 1, 1,920 gpm at 214.7111 °F (i.e., initial. post-LOCA ECCS/CSS recirculation), and Case 2, 1,920 gpm at 65 OF (i.e., long-term post-LOCA ECCS/CSS recirculation). Conservatively evaluating for a post-LOCA containment water level (i.e.,

minimum water level) at the initiation of ECCS/CSS recirculation for a LBLOCA equal to 2" strainer submergence (i.e., 39.25"), the water level is at Elevation 595.27' (i.e., 3.27' above KPS containment floor elevation of 592'-0"). The post-LOCA containment water level for long-term post-LOCA ECCS/CSS recirculation for a LBLOCA is Elevation 598.17' (i.e., 6.17' above KPS containment floor elevation of 592'-0") [Reference 9.21].

Originated By: (a/_ __ _ Date: /A TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 23 of 32 1

Apul PERFORMANCE CON IRACIING INC Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

- Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 Elevation 598.17' results in 36.79" of strainer submergence during long-term recirculation.

VOID FRACTION PCI Technical Documents No. TDI-6008-07, Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer) - Kewaunee Power Station provides the basis for addressing flashing across the strainer surface. The subject calculation provides the specific methodology, basis, and assumptions for evaluating KPS with regard to the subject issue. However, the subject document initially only addressed the KPS Design Basis case associated with a LBLOCA. Subsequently, the Staff has identified a number of other related issues associated with flashing (void fraction) including head loss at the strainer module debris bed and the evolution of gas (de-aeration) downstream of the strainer module that could reach the ECCS/CSS pump inlets.

Therefore, the strainer head loss is evaluated for two (2) distinct LBLOCA scenarios (i.e., Case 1,920 gpm at 214.7111 OF, and Case 2, 1,920 gpm at 65 OF) based on two (2) distinct time periods (i.e., post-LOCA short-term and post-LOCA long-term). In addition, the related issues of flashing and the evolution of gas (de-aeration) downstream of the strainer module are also evaluated for KPS.

LBLOCA Scenario The post-LOCA short-term is defined as the time period from LOCA initiation to the time when stable containment pressure, post-LOCA containment fluid temperature, and post-LOCA containment water level are achieved, which would occur in the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the initiation of the LOCA. During the initial period of the accident response, chemical precipitate debris and the associated effects on strainer head loss are not required to be considered in the determination of strainer head loss since chemical precipitate debris would not have begun to fully influence the strainer head loss for several more days. The post-LOCA long-term is defined as the post-LOCA containment conditions beyond the initial 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> through the end of the post-LOCA mission time (i.e., 30 days). The long-term post-LOCA period conservatively includes the maximum quantity of chemical precipitate debris and its effect on strainer head loss.

In accordance with the guidance provided in USNRC Safety Guide 1.1 (Regulatory Guide 1.10), the post-LOCA containment initial conditions must be exactly the same as the pre-LOCA conditions for evaluating NPSH. In other words, immediately before the initiation of a LOCA, the pressure and temperature in the containment are at 'normal' operating conditions - usually atmospheric pressure and the associated 'normal' operating temperature. Accordingly, it is very conservatively assumed that the containment post-LOCA fluid peak temperature is >212 OF and atmospheric pressure Originated By: (i*/-f<. ,.**/4 Date:

ToI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 24 of 32 1

Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer) r pc i - Kewaunee Power Station PERFORMANCE conIRACtlnG INC Technical Document No. TDI-6008-07 CON* rlA(AlN "INC Revision 6 was utilized to evaluate the KPS strainer for flashing (void fraction). Based on the stated assumptions, this would result in a very conservative analysis. It is also recognized that the application of post-LOCA containment 'over-pressure' (i.e.,

containment accident pressure) was limited to NPSH calculations as discussed in USNRC Safety Guide 1.1 (Regulatory Guide 1.10). It should be noted that KPS does not take 'credit' for post-LOCA containment 'over-pressure' in their NPSH calculations. The recent issues of strainer blockage and associated head loss (i.e.,

RG 1.82 Rev. 3, GSI-191, and GL-2004-02) at the time SG 1.1 was developed were never considered with regard to the application of the 'over-pressure' credit for addressing strainer head loss rather than NPSH. It should be noted that KPS does not take 'credit' for post-LOCA containment 'over-pressure' in their evaluation of GL 2004-02 issues.

The USNRC safety evaluation report (SER) provided in Volume 2 of NEI 04-07 indicates that ECCS pumps can experience cavitation problems when inlet void fraction exceeds approximately 3%. Since it is very difficult (if not impossible) to calculate the actual percentage of flashing (void fraction) due to the many variables and dynamics of the post-LOCA strainer debris bed, PCI has chosen a solution that completely eliminates flashing (void fraction).

There are two (2) possible methods to address flashing. The first is to assess the static head of water based on the post-LOCA containment minimum water level. The static water head based on the height of the post-LOCA minimum containment water level to the centerline of the ECCS/CSS pump suction inlet must be determined. If the static water head height exceeds the calculated head loss across the strainer debris bed, then the static water head will have 'collapsed' any voids before they leave the containment (sump). In many cases this is the most straightforward and simple method of assessing flashing issues. However, if the static water head height does not exceed the calculated head loss across the strainer bed, then flashing is present. In this case, post-LOCA containment over-pressure credit is needed in order to eliminate the issue of flashing.

The issues of USNRC Safety Guide 1.1 requirements and GSI-191 with regard to credit of post-LOCA containment over-pressure was recently addressed by the Advisory Committee on Reactor Safeguards (ACRS) Letter of March 18, 2009, titled, Crediting Containment Overpressure in Meeting the Net Positive Suction Head Required to Demonstrate that the Safety Systems Can Mitigate the Accidents As Designed (Accession No: ML090700464).

LBLOCA SCENARIO FOR FLASHING At the initiation of the LBLOCA (i.e., Case 1, 1,920 gpm at 214.7111 OF), the amount of post-LOCA debris transported to the strainer will be less than that for the long-term KPS Design Basis LBLOCA. Unqualified coatings and 'wash-down' debris may not have Originated By: C Date: X TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 25 of 32 1

NPCI PERFORMANCE CONIRACiING INC Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

- Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 reached the sump. Post-LOCA chemical particulate debris per the WCAP [Reference 9.23] will not begin to form until the post-LOCA water temperature is approximately 140 OF or less. Therefore, the initial post-LBLOCA debris head loss will be much less than the evaluated KPS Design Basis debris head loss.

Utilizing the KPS Design Basis flow rate of 1,920 gpm for the LBLOCA, the CSHL and total strainer head loss (TSHL) based on the KPS strainer module arrangement were determined including uncertainty. Table Al-1 provides a summary of the estimated approximate head loss associated with the respective flow rates.

Table Al KPS LBLOCA Scenario Head Loss LBLOCA Scenario CSHL, ft TSHL W/O TSHL, ft of of water Chemical Debris, water ft of water Case 1, 1,920 gpm at 214.7111 OF 0.344 0.4444 0.5528 Case 2, 1,920 gpm at 65 OF 0.365 0.7384 1.1034 NOTE: The CSHL, TSHL without chemical debris, and the TSHL were determined based on a combination of PCI KPS calculations and KPS ARIJAREVA Large Flume Test Results. For Case 2, PC[ utilized.the calculated values in TDI -6008-05 & -06. For Case 1, since the subject temperature was not a KPS Design Basis temperature, PCi utilized the same calculation methodology and philosophy found in TDI-6008-05 & -06 to determine the CSHL, TSHL without chemicals debris, and the TSHL for the KPS specified Case 1 temperature of 214.7111 OF.

KPS is a Westinghouse 2 - loop NSSS based design. This design is unique because of the fact that before the Refueling Water Storage Tank (RWST) reaches its 'low' level alarm with respect to remaining volume, post-LOCA ECCS/CSS recirculation is initiated before the RWST is 'emptied'. In other words, ECCS/CSS recirculation is occurring at the same time that the RWST is being depleted by the ECCS/CSS injection process.

Therefore, the KPS strainer experiences continuous rising post-LOCA containment water level following the initiation of ECCS/CSS recirculation until the RWST is depleted.

A conservative timeline for the KPS post-LOCA events [Reference 9.18, 9.20, 9.21, and 9.22] is as follows:

T + 0 min. LBLOCA occurs and RWST injection is initiated for ECCS/CSS Post-LOCA Containment Water Level: El. 592' (0.00')

Sump Temperature: -120 OF T + 29 min ECCS/CSS recirculation is manually initiated, assuming 8 minutes operator response time Originated By: ______/_ _______ Date: le",

TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 26 of 32 1

EPCI PERFORMANCE CONIRACIING INC Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

- Kewaunee Power Station Technical Document No. TDI-6008-07

ý Jmý Revision 6 Post-LOCA Containment Water Level: El. 595.62 (+3.62' & rising)

Sump Temperature: -212 °F T + 43 min. RWST injection ends; RWST at 4% level Post-LOCA Containment Water Level: El. 598.17 (+6.17' final)

Sump Temperature: -206 °F It has been determined that post-LOCA chemical precipitate debris does not begin to form until the post-LOCA containment fluid has dropped to 140 OF or lower in order to

'support' formation of the precipitates. Therefore, the TSHL for temperatures greater than 140 OF should not include the head loss associated with chemical precipitate debris.

Based on this scenario of minimal initial debris transport and chemical particulate debris generation, the KPS LBLOCA scenario can be evaluated by simply utilizing the first method of comparing the submerged strainer elevation static head of water (i.e.,

submergence depth) to the top of the strainer at the initiation of ECCS/CSS recirculation (i.e., 595.62' - 595.10' = 0.52') and to the ECCS/CCS inlet pipe centerline elevation (i.e., 595.62'- 586.17" = 9.45'), which is 0.52 and 9.45 ft of water respectively based on the post-LOCA containment minimum water level to the calculated CSHL. However, the post-LOCA containment water level will continue to rise to a minimum high water elevation of 598.17'. Therefore, based on the final high water minimum level, the submerged strainer elevation static head of water (i.e., submergence depth) to the top of the strainer at the initiation of ECCS/CSS recirculation (i.e., 598.17' - 595.10' = 3.07')

and to the ECCS/CCS inlet pipe centerline elevation (i.e., 598.17' - 586.17" = 12.00'), is 3.07 and 12.00 ft of water respectively. Table A1-2 provides a summary comparison of the LBLOCA Strainer Submergence scenario for CSHL.

Table A1 KPS LBLOCA Strainer Submergence Scenario Head Loss Comparison for CSHL LBLOCA Scenario CSHL, ft of water Comparison, ft of water Case 1,1,920 gpm at 214.7111 OF 0.344 0.52 > 0.344 Case 2, 1,920 gpm at 65 OF 0.365 3.07 > 0.365 NOTE: For Case 2 at 65 'F, the post-LOCA containment water level will be at the high water level of Elevation 598.17', or a strainer I submergence level of 3.07'.

Originated By: CX - I I Date: / /

TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 27 of 32 1

NPICI PERFORMANCE CONRIIACIING INC Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

- Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 Based on the results summarized in Table A1-2, there is sufficient strainer submergence to preclude flashing at the KPS strainer debris bed.

Table A1-3 provides a summary comparison of the LBLOCA Strainer Submergence scenario for the TSHL without Chemical Debris Head Loss.

Table A1 KPS LBLOCA Strainer Submergence Scenario Head Loss Comparison for TSHL Without Chemical Debris Head Loss LBLOCA Scenario TSHL WIO Comparison, ft of Chemical Debris water HL, ft of water Case 1, 1,920 gpm at 214.7111 OF 0.4444 0.52 > 0.4444 Case 2, 1,920 gpm at 65 OF 0.7384 3.07 > 0.7384

__ I NuOTE: F-or Lase 2 at 5 -F, tne post-LU;/ containment water ievel will De at te nign water level o0 Elevation 5.17, or a strainer submergence level of 3.07'. 1 Based on the results summarized in Table A1-3, there is sufficient strainer submergence to preclude flashing at the KPS strainer debris bed.

Table A1-4 provides a summary comparison of the LBLOCA Strainer Submergence scenario for the TSHL.

Table A1 KPS LBLOCA Strainer Submergence Scenario Head Loss Comparison for TSHL LBLOCA Scenario TSHL, ft of water Comparison, ft of water Case 1, 1,920 gpm at 214.7111 OF 0.4444 0.52 > 0.4444 Case 2, 1,920 gpm at 65 °F 1.1034 3.07 > 1.1034 NOTE: It should also be noted that the stated TSHL value for Case 1 of 0.4444 It of head loss is realistic and conservative. It is based on the WCAP [Reference 9.23] that concluded that chemical precipitate debris will not form at temperatures greater than 140 OF. Therefore, since the Case 1 temperature is 214.7111 OF, chemical precipitate debris will not form and is not considered as part of the TSHL. For Case 2 at 65 OF, the post-LOCA containment water level will be at the high water level of Elevation 598.17', or a strainer submergence level of 3.07'.

Originated By: lx 'ýýel'4dxv v

Date: /

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Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

SPCi - Kewaunee Power Station PERFORMANCE Technical Document No. TDI-6008-07 CONIRACIING INC Revision 6 Tables A1-2, A1-3 and A1-4 have shown that flashing will not occur at the KPS strainer perforated plate and/or associated debris bed based on the various 'types' of head loss (i.e., CSHL, TSHL without Chemical Precipitate Debris, and TSHL). In the highly unlikely event that potential flashing does take place at the strainer discharge and/or within the associated KPS sump, and voids occur, Table A1-5 provides a summary comparison of the LBLOCA Strainer Submergence for all of the various 'types' of head loss related to the ECCS/CSS Inlet Pipe Submergence scenario.

Table A1 KPS LBLOCA ECCS/CSS Inlet Pipe Submergence Scenario LBLOCA Scenario CSHL, ft TSHL W/O TSHL, ft Comparison, ft of of water Chemical of water water Debris, ft of water Case 1, 1,920 gpm at 0.344 0.4444 0.5528 12.00 > 0.5528 >

214.7111 OF 0.4444 > 0.344 Case 2, 1,920 gpm at 0.365 0.7384 1.1034 12.00 > 1.1034 >

65 OF 0.7384 > 0.365 Based on the results summarized in Table A1-5, there is sufficient ECCS/CSS inlet pipe submergence to preclude flashing voids from leaving the KPS sump.

An additional evaluation regarding the second method assumed that the static water head height does not exceed the calculated head loss (i.e., across the strainer bed),

and therefore flashing is present. It should be noted that for KPS, this is not the case.

However, PCI evaluated this case for KPS regarding post-LOCA containment over-pressure credit in order to eliminate the issue of void fraction.

The maximum LBLOCA scenario head loss for KPS based on the Beyond Design Basis Supplemental Design Basis is 3.2860 ft of water (- 1.425 psi) at 65 OF for KPS. The KPS maximum allowable head loss of 10.00' results in an equivalent head loss of approximately 4.335 psi at 65 OF for KPS.

Accordingly, post-LOCA containment over-pressure of 1.425 psi or 4.335 psi at 65 OF would be required for KPS to prevent flashing at the strainer debris bed for the calculated (i.e., 1.425 psi or 3.2860 ft of water) and Design Basis allowable maximum head loss (i.e., 4.335 psi or 10.00 ft of water), respectively. Based on the KPS design basis and safety analysis report, there will always be more than adequate post-LOCA containment over-pressure to prevent flashing of the KPS strainer for the LBLOCA Originated By: 67/ Date: / ,Ie TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 29 of 32 1

Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

- Kewaunee Power Station PERFORMANCEL Technical Document No. TDI-6008-07 17,ý77,7,.,*

CONIRACIING ý INC Revision 6 scenario. The report indicates that there will be post-LOCA containment over-pressure of 39.3989 psia at 214.7111 OF.

In addition to the two (2) possible methods to address flashing at the KPS strainer debris bed for the Design Basis SBLOCA scenario, the static water head above the ECCS/CSS pump inlet lines within the sump always exceeds the 'worse-case' strainer total head loss, which is the LBLOCA Design Basis case. Accordingly, in both cases, any voids caused by flashing will have collapsed before they enter the ECCS/CSS pump inlet lines.

STRAINER DOWNSTREAM GAS EVOLUTION EVALUATION In the PCI Technical Documents No. TDI-6008-06, Total Head Loss (ECCS Recirculation Strainer) - Kewaunee Power Station the KPS head loss values were determined for the two (2) KPS Design Basis conditions of Case 1, 1,920 gpm at 214.7111 OF, and for Case 2, 1,920 gpm at 65 OF as 1.263 and 2.37 ft of water, respectively. The vortex, air ingestion, and void fraction analysis concluded that void fraction occurring at the strainer debris bed due to head loss and the accompanying post-LOCA conditions would be reversed and any voids would have collapsed before the strainer discharge fluid left the containment sump and entered the ECCS/CSS inlet lines. The net void fraction (i.e., net air production) is therefore 0%. Therefore, void fraction is not an issue for any of the post-LOCA fluid associated pressure and temperature combinations associated with the subject fluid flow from the strainer to the ECCS/CSS inlet lines.

It is recognized that a small amount of de-aeration will occur due to the difference in the solubility of air in water resulting from the pressure differential across the strainer and debris bed. A conservative assessment was made of the theoretical void fraction (air ingestion rate) which is expected to be minimal.

The solubility of air in water is inversely proportional to the water temperature. In other words, the solubility is a maximum at the lowest water temperature of interest. In addition, the solubility is proportional to absolute pressure. The difference of solubility is 0.023 g Air / kg Water per one atmosphere.

The KPS bounding differential pressure for the strainer is 10.00' (i.e., Design Basis Maximum Allowable Head Loss). Therefore, 10.00' = 3.048 m = 0.295 atm.

Conservatively assuming that the water entering the strainer is fully saturated with air, the bounding difference of air solubility in water is as follows:

0.295 x 0.023 = 0.006785 g Air / kg Water Originated By: /,,,

, - Date: /Z /, /

TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 30 of 32 1

.Pc I PERFORMANCE CON IRACIING INC Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

-Kewaunee Power Station Technical Document No. TDI-6008-07 Revision 6 The densities of air and water are:

Air: 1.169 kg/m 3 at 25 0C and one atmosphere Water: 997 kg/m 3 at 25 0C The volume ratio of air and water therefore is:

(0.000006785 kg Air / kg Water) / 1.169 kg/M 3 x 997 kg/m 3 = 0.00579 or 0.579%

The subject solubility value is at the top elevation of the strainer, actually at the water surface above the top of the strainer that is in contact with the containment post-LOCA atmosphere.

At the ECCS/CSS pump suctions from the KPS sump pit, the strainer discharge water experiences a pressure increase again due to the static water head (i.e., the water column above the ECCS/CSS pump suctions inlets within the sump). The minimum LBLOCA post-LOCA containment water elevation for evaluating 2" strainer submergence is 595.27', but the minimum high water elevation is 598.17'. The ECCS/CSS pump suction inlets in the sump are located at centerline elevation 586.17'.

This would theoretically result in an elevation difference of 9.1' or 12.00', respectively based on the post-LOCA containment water level evaluated. If the minimum post-LOCA water level of 595.27' is utilized, this results in a value, 9.1' of water which is less than the postulated strainer differential pressure of 10.00'. However, the ECCS/CSS pump inlets are located at elevation 569.396'. This would result in an elevation difference of 25.874', which is more than the postulated strainer differential pressure of 10.00'. In the case of the minimum high water elevation of 598.17', the postulated strainer differential pressure is less, 10.00' < 12.00'. Even though there would be no gas evolution for this case, evaluating the ECCS/CSS pump inlets located at elevation 569.396', results in 28.774'.

It should be further noted that the aforementioned discussion was based on a water temperature of 25 0C which is 77 OF. The KPS Design Basis minimum post-LOCA water temperature is 65 OF which is slightly less. Accordingly, at the KPS Design Basis minimum temperature the solubility of air in water would be approximately 15% higher than the conservatively calculated value of 0.579%.

Therefore any void fraction that could occur at the strainer debris bed is very minimal. If any should occur, it is reversed before the strainer discharge water leaves the sump due to the significant static head of water above the ECCS/CSS pump suction inlets within the sump. The net void fraction is therefore zero and is not a problem for any of Originated By: K(..s7,' S- - -7'-

1(e' Date:

TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 31 of 32 1

MPCI PERFORMANCE CONIRACIING INC Vortex, Air Ingestion & Void Fraction (ECCS Recirculation Strainer)

- Kewaunee Power Station Technical Document No. TDI-6008-07

---

IW- Revision 6 the KPS pressures and temperatures from the strainer to the ECCS/CSS pump suction inlets within the sump.

Even though it has been shown that there will be zero void fraction associated with the KPS strainer, the following assessment is provided to address potential void fraction from the sump outlet to the ECCS/CSS pump suction inlets. The assessment will utilize the same methodology utilized to assess void fraction within the sump by demonstrating that the elevation difference (i.e., static water head) between the sump outlet and the pump inlets is greater than the respective piping head losses.

The minimum elevation difference between the sump outlet (elevation 586.17') and the pump inlet elevation 569.396' is 16.774'. This difference is significantly more than the maximum allowable suction line head loss of 10.00' (which also includes the head loss due to the new strainer). Therefore, re-initiating void fraction downstream of the sump outlet is not possible. This analysis results in a void fraction of zero at the ECCS/CSS pump inlets.

Originated By: Date:

TDI-6008-07 Vortex, Air Ingestion & Void Fraction - Rev.6.doc Page 32 of 32 1

Serial No.10-025 Docket 50-305 ENCLOSURE L-1 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER MODULE STRUCTURAL EVALUATION Page 1 of 8

Serial No.10-025 Docket 50-305 ENCLOSURE L-1 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER MODULE STRUCTURAL EVALUATION tstfnr LI legs Figure 6.2 Side view of Strainer Module Page 2 of 8

Serial No.10-025 Docket 50-305 ENCLOSURE L-1 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER MODULE STRUCTURAL EVALUATION L2 Wend Figure 5.2 Axial view of Strainer Module Page 3 of 8

Serial No.10-025 Docket 50-305 ENCLOSURE L-1 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER MODULE STRUCTURAL EVALUATION Figure 6.5-1 GTSTRUDL Model (Horizontal Solid Model)

Page 4 of 8

Serial No.10-025 Docket 50-305 ENCLOSURE L-1 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER MODULE STRUCTURAL EVALUATION R Rcen Rcirc.end

/~ * ~ hback 6.10 End Cover Stiffener Configuration Page 5 of 8

Serial No.10-025 Docket 50-305 ENCLOSURE L-1 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER MODULE STRUCTURAL EVALUATION esprt 1'4 Vbolt.z I-

ý- e hkb e h klý-2ý Figure 6.14 Angle Iron Track Configuration for Mid Modules Vbolt.y.DP TV L sprt bolt.y.DP Figure 6.14 Angle Iron Track Configuration for the End Module Page 6 of 8

Serial No.10-025 Docket 50-305 ENCLOSURE L-1 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER MODULE STRUCTURAL EVALUATION 7.0 RESULTS AND CONCLUSIONS The results of this calculation indicate that the strainers meet the acceptance criteria for all applicable loadings. A summary of the maximum stress Interaction Ratios (calculated stress divided by allowable stress) is provided below.

Strainer Component Ref. Section Interaction Ratio (OBE DE3E)

External Radial Stiffener (Including Collars) 6.6 IRrad.sffnr T = (0.80 0.67 Tension Rods 6.6 IRrod T = (0.96 0.68)

Spacers 6.6 IRspacer T = (0.63 0.43)

Edge Channels 6.6 IRchan T = (0.66 0.57)

Seismic Stiffeners 6.6 IRseis.stfnr.H T = (0.76 0,

.58) )

)

Maintenance Hatch Cover Plate 6.6 lRmh.cover.2 = (0.82 0.55) 2-Disk Support Channels 6.6 IRsprt.2 T = (0.22 0.15)

Core Tube (Biggest Holes) 6.6 IRtube T = (0.05 0.03)

Perforated Plate (DP Case) 6.8.1 IRface.dp T = (0.64 0.54)

T Perforated Plate (Seismic Case) 6.8.1 IRface.bp = (0.06 0.09)

Perforated Plate (Edge Channels) 6.8.3 IRedgeT = (0.10 0.09)

Perforated Plate (Inner Gap) 6.8.4 IRgap T (0.10 0.14)

Wire Stiffener 6.9 IRwire = 0.59 Perforated Plate (Core Tube End Cap DPI Case) T 6.10.1 lRfront.end = (0.29 0.25 Perforated Plate (Core Tube End Cap Seismic Case) T 6.10.1 lRback end =(0.09 0.15)

Radial Stiffening Spokes of the End Cover Stiffener 6.10.2 IRspokeT = (0.71 0.62)

End Cover 6.10.4 IRcoverT = (0.71 0.62)

Page 7 of 8

Serial No.10-025 Docket 50-305 ENCLOSURE L-1 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER MODULE STRUCTURAL EVALUATION RESULTS AND CONCLUSIONS (Cont.)

Strainer Component Ref. Section Interaction Ratio End Cover Welds 6.11.1 T IRw.cover = (0.69 0.48)

Weld of Radial Stiffener to Core Tube 6.11.2 T IRweld.ct = (0.29 0.32)

Weld of Radial Stiffener to Seismic Stiffener 6.11.3 T lRweld.cb = (0.89 0.61)

Weld of hex coupling nut to M.H. cover plate T 6.11.4 IRweld.hex = (0.32 0.16)

Edge Channel Rivets 6.12.1 T IRrv.face = (0.05 0.04)

Inner Gap Hoop Rivets 6.12.2 T IRrv.gap = (0.02 0.03)

T End Cover Rivets 6.12.3 IRrv.end = (0.01 0.01)

Module-to-module Sleeve 6.13.1 T IRsleeve = (0.07 0.10)

Module-to-module Latch Connection 6.13.2 T IRlatch = (0.29 0.46)

Mounting Pins 6.14.1 *T lRboT = (0.91 0.66)

Clevis Hitch Pins 6.14.1 T IRhitch = (0.21 0.26)

Angle Iron Tracks 6.14.2 IRangle T = (0.76 0.61)

Expansion Anchors 6.14.3 T IRhkb = (0.39 0.90)

Alternate Angle Iron Welds 6.14.4 T IRweld.alt = (0.43 0.32)

Bolt connecting cover plate to support channels 6.14.5 T lRbolt.2 = (0.14 0.09)

Lift Case 6.15 IRlift = 0.76 Outage Case 6.16 IRoutage = 0.77 Page 8 of 8

Serial No.10-025 Docket 50-305 ENCLOSURE L-2 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER PIPING STRUCTURAL EVALUATION Page 1 of 6

Serial No.10-025 Docket 50-305 ENCLOSURE L-2 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER PIPING STRUCTURAL EVALUATION A01 A02 MODEL PLOT OF STRAINER PIPING AAM Y'

yY 407 Page 2 of 6

Serial No.10-025 Docket 50-305 ENCLOSURE L-2 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER PIPING STRUCTURAL EVALUATION C

Figure 6.7.1 Three-way Restraint bpit opit Figure 6.6.1 - Sump Pit Cover Details Page 3 of 6

Serial No.10-025 Docket 50-305 ENCLOSURE L-2 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER PIPING STRUCTURAL EVALUATION Lch Fiqure 6.6.2 - Sump Pit Layout R = 13.5" R = 14.5" Figure 6.5.1 - Flange to Sump Cover Plate Page 4 of 6

Serial No.10-025 Docket 50-305 ENCLOSURE L-2 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER PIPING STRUCTURAL EVALUATION 7.0 RESULTS AND CONCLUSIONS A summary of the maximum calculated piping stresses is shown in Section 6.4. Calculated support component stresses are shown in Section 6.7. The interaction ratio for the pipe stresses, flanges, sump cover plate, and supports is shown below:

Pipe Stresses lRpipe:= max(IRnormal, IRupset, IRfaulted, IRthermal) IRpipe = 0.28 Stress Summary for other Components Component Ref. Section Interaction Ratio In-Line Flanme Flange Bolting 6.5.1 IRbolt1 = 0.43 Flange Bending 6.5.1 IRflangel = 0.46 Flange Weld to Pipe 6.5.1 IRwj = 0.19 Flange to Sump Cover Plate Flange Bending 6.5.2 IRflange.plate = 0.94 Flange Weld to Pipe 6.5.2 IR,2 = 0.84 Flange Plate Tabs 6.5.2 IRtabs = 0.38 Hold Down Bolts 6.5.2 Rtab.bofts = 0.30 Sump Cover Plate Cover Plate Bending 6.6 IRpit.pl = 0.97 Weld Sump Cover Plate to Inset Plate 6.6 lRweld.sump = 0.22 Inset Plate Bending 6.6 Rinspl = 0.19 Channel Bending 6.6 IRch = 0.43 Channel Bending Local Stress 6.6 IR10o = 0.09 Page 5 of 6

Serial No.10-025 Docket 50-305 ENCLOSURE L-2 (RAI 37) PHOTOS AND EXCERPTS FROM STRAINER PIPING STRUCTURAL EVALUATION Component Ref. Section Interaction Ratio Pipe Supports Angle Normal Stress 6.7 IRangle norm = (0.57) Emerg Angle Shear Stress 6.7 (/0.05 IRangle-sh =.0.05)

(0.745" Expansion Anchors 6.7 IRbolt-supp = 0.)

(~0.99J Baseplate 6.7 1Rbpl = 0.70I.

(0.908" Weld of Angle to Baseplate 6.7 IRweld = ,0.9)

(0.76)

Saddle Plate Bending 6.7 1RspLbd =032 Saddle Plate Shear 6.7 Rsplsh = (0.95 (0.37 Saddle Plate Welds 6.7 R 1 p =0.33 I0.27)

Saddle Plate Pins 6.7 (Rpin 0.25)

( 0.38)

Shear Lugs 6.7 IRiugs 0.11)

Integral Welded Attachment 6.8 IRiwa = 0.46 The evaluation of the piping and piping supports associated with the suction strainers has shown that the pipe stresses and support loads are acceptable. The piping stresses, flanges, and support component stresses are within their respective applicable limits and are therefore acceptable.

Page 6 of 6

Serial No.10-025 Docket 50-305 ENCLOSURE M (RAI 40) REFUELING CAVITY DRAIN LOCATION Page 1 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE M (RAI 40) REFUELING CAVITY DRAIN LOCATION Reactor Coolant Limiting Hot Leg Break Refueling Cavity Drain in Pump Vault below the Steam recessed area below refueling Generator crane and below fuel transfer lifting frame Page 2 of 4

(

Serial No.10-025 Docket 50-305 ENCLOSURE M (RAI 40) REFUELING CAVITY DRAIN LOCATION Page 3 of 4

Serial No.10-025 Docket 50-305 ENCLOSURE M (RAI 40) REFUELING CAVITY DRAIN LOCATION Standpipe (not installed)

Page 4 of 4