ML080770404

AEP:NRC:8054-02, Attachment 5, Figure A5-41, Scotch 77 Fire Retardant Tape Test 1 Post-Test Picture to Attachment 7, Regulatory Commitments.

ML080770404
Person / Time
Site:	Cook
Issue date:	02/29/2008
From:	Indiana Michigan Power Co
To:	Office of Nuclear Reactor Regulation
References
GL-04-002 AEP:NRC:8054-02
Download: ML080770404 (48)

Text

Attachment 5 to AEP:NRC:8054-02 Page 21 Fiaure A5-41 Scotch 77 Fire Retardant TaDe Test I Post-Test Picture Figure A5-42 Scotch 77 Fire Retardant Tape Test I Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 22 Figure A5-43 Scotch 77 Fire Retardant Tape Test I Post-Test Picture j Figure A5-44 Scotch 77 Fire Retardant Tape Test 2 Pre-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 23 Fiqure A5-45 Scotch 77 Fire Retardant Tape Test 2 Post-Test Picture ire A5-46 Scotch 77 Fire Retardant Tape Test 2 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 24 Fiaure A5-47 Scotch 77 Fire Retardant TaDe Test 3 Pre-Test Picture Figure A5-48 Scotch 77 Fire Retardant Tape Test 3 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 25 Fioure A5-49 Scotch 77 Fire Retardant TaDe Test 4 Pre-Test Picture Figure A5-50 Scotch 77 Fire Retardant Tape Test 4 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 26 Fioure A5-51 Scotch 77 Fire Retardant TaDe Test 5 Pre-Test Picture ure A5-52 Scotch 77 Fire Retardant Tape Test 5 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 27 Fiaure A5-53 Scotch 77 Fire Retardant Tape Test 5 Post-Test Picture Fiqure A5-54 Electromark Labels Test I Pre-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 28 Fiaure A5-55 Electromark Labels Test I Post-Test Picture A5-56 Electromark Labels Test 2 Pre-Test Picture Attachment 5 to AEP:NRC:8054-02 Figure A5-57 Electromark Labels Test 2 Post-Test Picture Page 29 Fiaure A5-58 Electromark Labels Test 3 Pre-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 30 Figure A5-59 Electromark Labels Test 3 Post-Test Picture ire A5-60 Electromark Labels Test 4 Pre-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 31 Figure A5-61 Electromark Labels Test 4 Post-Test Picture ire A5-62 Jacketed Armaflex Insulation Test I Pre-Test Picture Attachment 5 to AEP:NRC:8054-02 Fiqure A5-63 Jacketed Armaflex Insulation Test I Post-Test Picture Page 32 Figure A5-64 Jacketed Armaflex Insulation Test I Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 33 Fiaure A5-65 Jacketed Armaflex Insulation Test I Post-Test Picture e A5-66 Jacketed Armaflex Insulation Test 2 Pre-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 34 Figure A5-67 Jacketed Armaflex Insulation Test 2 Post-Test Picture Figure A5-68 Jacketed Armaflex Insulation Test 2 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 35 Figure A5-69 Jacketed Armaflex Insulation Test 2 Post-Test Picture Fioure A5-70 Jacketed Armaflex Insulation Test 3 Pre-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 36 Fioure A5-71 Jacketed Armaflex Insulation Test 3 Post-Test Picture Figure A5-72 Jacketed Armaflex Insulation Test 3 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 37 Figure A5-73 Jacketed Armaflex Insulation Test 3 Post-Test Picture ire A5-74 Jacketed Armaflex Insulation Test 4 Pre-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 38 Flaure A5-75 Jacketed Armaflex Insulation Test 4 Post-Test Picture Figure A5-76 Jacketed Armaflex Insulation Test 4 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 39 Ficure A5-77 Jacketed Armaflex Insulation Test 4 Post-Test Picture Figure A5-78 Jacketed Armaflex Insulation Test 5 Pre-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 40 Ficiure A5-79 Jacketed Armaflex Insulation Test 5 Post-Test Picture ire A5-80 Jacketed Armaflex Insulation Test 5 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 41 Fiqure A5-81 Jacketed Armaflex Insulation Test 5 Post-Test Picture ire A5-82 Jacketed Armaflex Insulation Test 5 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 42 Figure A5-83 Jacketed Armaflex Insulation Test 6 Pre-Test Picture Figure A5-84 Jacketed Armaflex Insulation Test 6 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 43 Figure A5-85 Jacketed Armaflex Insulation Test 6 Post-Test Picture Figure A5-86 Jacketed Armaflex Insulation Test 6 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 44 Fiqure A5-87 Jacketed Armaflex Insulation Test 6 Post-Test Picture Fiqure A5-88 Jacketed Armaflex Insulation Test 7 Pre-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 45 Fiqure A5-89 Jacketed Armaflex Insulation Test 7 Post-Test Picture Figure A5-90 Jacketed Armaflex Insulation Test 7 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 46 Fioure A5-91 Jacketed Armaflex Insulation Test 8 Picture\Figure A5-92 Jacketed Armaflex Insulation Test 8 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 47 Fiqure A5-93 Jacketed Armaflex Insulation Test 9 Pre-Test Picture ire A5-94 Jacketed Armaflex Insulation Test 9 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 48 Fiaure A5-95 Jacketed Armaflex Insulation Test 10 Pre-Test Picture Figure A5-96 Jacketed Armaflex Insulation Test 10 Post-Test Picture Attachment 5 to AEP:NRC:8054-02 Page 49 Fiaure A5-97 Jacketed Armaflex Insulation Test 10 Post-Test Picture ATTACHMENT 6 TO AEP:NRC:8054-02 RESPONSES TO NRC REQUEST FOR ADDITIONAL INFORMATION Unless otherwise noted, the sections referenced are from Attachment 3.No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses Plant Materials Identify the amounts (i.e., surface area) of the following materials that are: 2a (a) submerged in the containment pool following a loss-of-coolant accident (LOCA), 2al -aluminum This value is provided in Table 3o4a-3, Containment Materials.

2a2 -zinc (from galvanized steel and from This value is provided in Table 3o4a-3, Containment Materials.

inorganic zinc coatings)2a3 -copper From Section 3.o.4.a) -Per WCAP-16530 methodology, this material is not considered as a participant in sump pool chemistry.

2a4 -carbon steel not coated From Reference 148, there is no carbon steel that is not coated.2a5 -uncoated concrete This value is provided in Table 3o4a-3, Containment Materials.

2b (b) in the containment spray zone following a LOCA: 2bl -aluminum This value is provided in Table 3o4a-3, Containment Materials.

-zinc (from galvanized steel and from This value is provided in Table 3o4a-3, Containment Materials.

inorganic zinc coatings)2b3 -copper From Section 3.o.4.a) -Per WCAP-16530 methodology, this material-is not considered as a participant in sump pool chemistry.

2b4 -carbon steel not coated From Reference 148, there is 32,666 ft 2 of carbon steel that is not 2b4_ coated.2b5 -uncoated concrete This value is provided in Table 3o4a-3, Containment Materials.

Attachment 6 to AEP:NRC:8054-02 Page 2 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses Compare the amounts of these materials in the A comparison between the ICET material quantities and the quantities submerged and spray zones at your plant relative used for testing at the strainer vendor, CCI, was not performed since to the scaled amounts of these materials used in an additional 30-day integrated chemical effects~test was also 2c the Nuclear Regulatory Commission (NRC) performed, and there was not an ICET that matched the CNP nuclear industry jointly-sponsored Integrated environment.

As stated in the response to Information Item 3.o, the Chemical Effects Tests (ICET) (e.g., 5x the results of the 30-day test will be provided in the final response to GL amount of uncoated carbon steel assumed for 2004-02.the ICETs).2cl -aluminum Refer to the response to Information Item 3.o for the quantities of-zinc (from galvanized steel and from materials used for chemical effects testing at the strainer vendor CCI.2c2 inorganic zinc coatings)

The total quantity of zinc coated steel material in containment is 2c3 -copper 71,162 ft 2 (submerged) and 504,728 ft 2 (non-submerged).

The total 2c4 -carbon steel not coated quantity of copper is 1022 ft 2 (submerged) and 39,735 ft 2 5- uncoated concrete (unsubmerged).

The total quantity of uncoated carbon steel is 2c5 -32,666 ft 2 (unsubmerged).

Identify the amount (surface area) and material (e.g., CNP does not currently have any scaffold material stored in aluminum) for any scaffolding stored in containment, containment.

However, procedures allow locating a small quantity of Indicate the amount, if any, that would be submerged galvanized scaffolding material in the annulus region (submerged) or in the containment pool following a LOCA. Clarify if upper containment (subject to spray) to support on-line work. This scaffolding material was included in the response to quantity would be insignificant compared to the total quantity of Question 2. galvanized steel in containment.

Therefore, scaffolding material was not included in Table 3o4a-3, which is referenced in the response to Question 2.Provide the type and amount of any metallic paints CNP does not have any metallic paints that would be exposed to spray or non-stainless steel insulation jacketing (not or be submerged in the containment pool. The only known metallic included in the response to Question 2) that would paint in containment, other than cold galvanizing (which is accounted 4 be either submerged or subjected to containment for as an unqualified coating), is applied to the ice condenser floor spray. cooling isolation valves which are fully encapsulated and not subjected to jet impingement.

CNP does not have any non-stainless steel insulation jacketing that would be submerged or subjected to spray.

Attachment 6 to AEP:NRC:8054-02 Page 3 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses SContain*ment Pool Chemistry,__

___Provide the expected containment pool pH during The values for the assumed pool pH values are provided in Table the emergency core cooling system (ECCS) 3o4a-2, "pH Time History & Water Volumes." The CNP calculation recirculation mission time following a LOCA at the that provided the input to the CNP post-LOCA chemical effects 5 beginning of the fuel cycle and at the end of the fuel analysis (Reference 147) assumed both a maximum RCS boron cycle. Identify any key assumptions.

concentration and minimum RCS boron concentration, reflective of beginning of fuel cycle and end of fuel cycle conditions, for determination of minimum and maximum pH conditions.

For the ICET environment that is the most similar to The post-accident containment pool at CNP does not match any of the your plant conditions, compare the expected ICET environments.

The conditions identified in ICET 4 are the containment pool conditions to the ICET conditions closest to CNP conditions.

However, ICET 4 does not include the 6 for the following items: boron concentration, buffering sodium tetraborate contribution that would exist at CNP, and the pH is agent concentration, and pH. Identify any other greater than determined for CNP. The response to Information Item significant differences between the ICET 3.o.4 provides the values used for determination of chemical effects.environment and the expected plant-specific The ICET data was not used for determination of pool conditions.

environment.

For a LBLOCA, provide the time until ECCS external The time until the initiation of the manual recirculation sequence is recirculation initiation and the associated pool provided in the response to Information Item 3.g.5. The remaining 7 temperature and pool volume. Provide estimated information is provided in the response to Information Item 3.o.4.pool temperature and pool volume 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after a Figure 3o4a-2 provides the sump water temperature at approximately LBLOCA. Identify the assumptions used for these 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of 138 0 F, which assumes minimum ice melt.estimates.

P,. !ant!,,Specific Chemical Effects <11<Discuss your overall strategy to evaluate potential This information is provided in the response to Information Item 3.o.chemical effects including demonstrating that, with chemical effects considered, there is sufficient net 8 positive suction head (NPSH) margin available during the ECCS mission time. Provide an estimated date with milestones for the completion of all chemical effects evaluations.

Attachment 6 to AEP:NRC:8054-02 Page 4 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses Identify, if applicable, any plans to remove certain The materials that were removed from containment are described in 9 materials from the containment building and/or to the response to Information Item 3.i.5. I&M currently has no plans to make a change from the existing chemicals that change any existing chemicals that buffer the containment pool pH'buffer containment pool pH following a LOCA. following a LOCA.If bench-top testing is being used to inform plant The testing described in the response to Information Item 3.0 used specific head loss testing, indicate how the bench- bench top testing at both CCI and ALION. The inputs for this bench top test parameters (e.g., buffering agent top testing used plant-specific parameters (References 67, 69, and concentrations, pH, materials, etc.) compare to your 153).plant conditions.

Describe your plans for addressing 10 uncertainties related to head loss from chemical The response to Information Item Section 3.0 describes the use of the effects including, but not limited to, use of chemical results of chemical effects testing.surrogates, scaling of sample size and test durations.

Discuss how it will be determined that allowances made for chemical effects are conservative.

Attachment 6 to AEP:NRC:8054-02 Page 5 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses Plant Environ~nent Spocifi&K V.V2 Provide a detailed description of any testing that has This information is provided in the response to Information Item 3.o.been or will be performed as part of a plant-specific chemical effects assessment.

Identify the vendor, if applicable, that will be performing the testing.Identify the environment (e.g., borated water at pH 9, deionized water, tap water) and test temperature for any plant-specific head loss or transport tests.Discuss how any differences between these test 11 environments and your plant containment pool conditions could affect the behavior of chemical surrogates.

Discuss the criteria that will be used to demonstrate that chemical surrogates produced for testing (e.g., head loss, flume) behave in a similar manner physically and chemically as in the ICET environment and plant containment pool environment.

For your plant-specific environment, provide the This information is provided in the response to Information Item 3.o.13.maximum projected head loss resulting from chemical effects (a) within the first day following a 12 LOCA, and (b) during the entire ECCS recirculation mission time. If the response to this question will be based on testing that is either planned or in progress, provide an estimated date for providing this information to the NRC.

Attachment 6 to AEP:NRC:8054-02 Page 6 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses__ICET 1 and ICET 5 Plants~Results from the ICET #1 environment and the ICET#5 environment showed chemical products appeared to form as the test solution cooled from the constant 140°F° test temperature.

Discuss how these results are being considered in your evaluation of chemical effects and downstream effects.13 The chemical effects testing described in the response to Information 3.o was performed at temperatures less than the expected CNP post-accident temperature.

Information related to the ALION integrated chemical effects testing, and the downstream effects analysis results will be provided as given in the response to Information Item 2. As discussed in the response to RAI 6, CNP is not an ICET 5 plant. CNP is not a fiberglass insulation plant. An update to this RAI will not be provided since the only fiberglass debris at CNP is the assumed quantity of fiber from latent debris.

Attachment 6 to AEP:NRC:8054-02 Page 7 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses.. ....Coatings.

.$ Y ii___ Generic -A//lPlants

~ ______________________________

25 Describe how your coatings assessment was used to identify degraded qualified/acceptable coatings and determine the amount of debris that will result from these coatings.

This should include how the assessment technique(s) demonstrates that qualified/acceptable coatings remain in compliance with plant licensing requirements for design basis accident (DBA) performance.

If current examination techniques cannot demonstrate the coatings' ability to meet plant licensing requirements for DBA performance, licensees should describe an augmented testing and inspection program that provides assurance that.the qualified/acceptable coatings continue to meet DBA performance requirements.

Alternately, assume all containment coatings fail and describe the potential for this debris to transport to the sump.The response to Information Item 3.h.7 describes the safety-related coatings program.N The response to Information Items 3.h.5 and 3.h.6 describes the methodology and assumptions for determining the debris produced -from the identified coatings.Tables 3h5-1 through 3h5-4 provide the amount of coating debris for the DEGB and the DGBS breaks.The response to Information Item Section 3.i describes the coatings assessment program and the changes that have been made to enhance that program.

Attachment 6 to AEP:NRC:8054-02 Page 8 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses SPlantS ecifc '. I I Provide test methodology and data used to support a The information is provided in the response to Information Items 3.h.5 zone of influence (ZOI) of 5.0 LID. Provide and 3.h.6.justification regarding how the test conditions simulate or correlate to actual plant conditions and will ensure representative or conservative treatment in the amounts of coatings debris generated by the 26 interaction of coatings and a two-phase jet. Identify all instances where the testing or specimens used deviate from actual plant conditions (i. e., irradiation of actual coatings vice samples, aging differences, etc.). Provide justification regarding how these deviations are accounted for with the test demonstra tin the proposed ZOI.ý29 Not7 aplicable.

Attachment 6 to AEP:NRC:8054-02 Page 9 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses The NRC staff's safety evaluation (SE) addresses The information is provided in response to Information Items 3.f.4, two distinct scenarios for formation of a fiber bed on 3.f.6, 3.h.3, and 3.h.4.the sump screen surface. For a thin bed case, the SE states that all coatings debris should be treated as particulate and assumes 100% transport to the sump screen. For the case in which no thin bed is formed, the staff's SE states that the coatings debris should be sized based on plant-specific analyses for debris generated from within the ZOI and from outside the ZOI, or that a default chip size equivalent 30 to the area of the sump screen openings should be used (Section 3.4.3.6).

Describe how your coatings debris characteristics are modeled to account for your plant-specific fiber bed (i. e. thin bed or no thin bed). If your analysis considers both a thin bed and a non-thin bed case, discuss the coatings' debris characteristics assumed for each case. If your analysis deviates from the coatings' debris characteristics described in the staff-approved methodology, provide justification to support your assumptions.

Your submittal indicated that you plan to use a debris The response to Information Item 3.e.4 documents that Dis were not interceptor as a method to impede transport of debris installed to specifically limit debris transport to either the main or to the ECCS sump screen. What is the amount (in remote strainers.

31 either volume or percentage) of debris that is expected to be captured by the interceptor?

Is there an evaluation for the potential to overload the debris interceptor?

Attachment 6 to AEP:NRC:8054-02 , Page 10 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses What structural analysis was performed on the The DI provided at the flood-up overflow wall was analyzed for dead debris interceptor design? load, seismic, hydrostatic, and hydrodynamic loading assuming it was 32 fully blocked withý debris, and the water temperature was at 236 0 F (which is significantly above the maximum expected temperature), per References 51 and 63.33 You indicated that you would be evaluating downstream effects in accordance with WCAP 16406-P. The NRC is currently involved in discussions with the Westinghouse Owner's Group (WOG) to address questions/concerns regarding this WCAP on a generic basis, and some of these discussions may resolve issues related to your particular station. The following issues have the potential for generic resolution; however, if a generic resolution cannot be obtained, plant-specific resolution will be required.

As such, formal RAIs will not be issued on these topics at this time, but may be needed in the future. It is expected that your final evaluation response will specifically address those portions of the WCAP used, their applicability, and exceptions taken to the WCAP. For your information, topics under ongoing discussion include: Refer to the response to Information Items 3.m and 3.n. As tabulated in Attachment 7 to this letter, I&M has committed to provide the response to this information item following completion of the associated analysis.a. Wear rates of pump-wetted materials and the effect of wear on component operation b. Settling of debris in low flow areas downstream of the strainer or credit for filtering leading to a change in fluid composition 33c c. Volume of debris injected into the reactor vessel and core region 33d d. Debris types and properties Attachment 6 to AEP:NRC:8054-02 Page 11 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses 33e e. Contribution of in-vessel velocity profile to the formation of a debris bed or clog f. Fluid and metal component temperature impact 33g g. Gravitational and temperature gradients 33h h. Debris and boron precipitation effects 33i i. ECCS injection paths 33j 1. Core bypass design features 33k k. Radiation and chemical considerations 331 L Debris adhesion to solid surfaces 33m m. Thermodynamic properties of coolant Your response to GL 2004-02 question (d) (viii) An active approach was not considered due to the complexity of indicated that an active strainer design will not be design. Backflushing is not being credited for design basis mitigation used, but does not mention any consideration of any capability.

As described in the response in Section 3.f.4, testing was 34 other active approaches (i.e., backflushing).

Was an performed that sequentially reduced flow from 100% to 0%, and then active approach considered as a potential strategy or restarted flow with subsequent increase back to 100%. The head loss backup for addressing any issues? plots provided in that section demonstrate the results of this flow sequencing.

The licensee states that the final containment The response to Information Item 3.d provides the response to this walkdowns for Unit I and Unit 2 will be completed in item.accordance with Nuclear Energy Institute (NEI)02-01 during-the fall 2006 and fall 2007 outages, 35 respectively.

The licensee also states that bounding analyses have already been completed in the areas of debris generation and transport.

Please discuss the plans to incorporate the results of these future containment walkdowns into these analyses.

Attachment 6 to AEP:NRC:8054-02 Page 12 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses The licensee states that testing to support other than 100% fines generation for calcium silicate (Cal-Sil)and Marinite insulation fragments will be completed in March 2006. Please provide a description of this test plan-including purpose for this testing. The staff expects that the licensee will provide information to justify the plant-specific application for the Cal-Sil and Marinite debris size distribution that results from such testing.36 The Cal-Sil and Marinite size distribution, with the supporting justification is provided in the response to Information Item 3.b.Additional testing was performed to determine the maximum quantity of fines that would be generated from the spray, dissolution, and pool flow erosion of Cal-Sil and the pool flow erosion of Marinite pieces.This testing was performed by ALION and determined that a bounding quantity of 17% fines would be generated from Marinite pieces. This testing was performed with I&M supplied materials that were the same as those installed in CNP Unit 1 and Unit 2 containments.

The basic methodology that was used for the testing was as follows:* The erosion tests were conducted at temperatures between 63 0 F (no flow tests) and up to 11 0°F (for flow and spray erosion tests) in reverse-osmosis treated water.* Dissolution tests were performed at 190°F +/- 5 0 F with 3000 ppm boron under five different sump chemistries.

• Flow erosion testing was conducted at a flow velocity of 0.4 ft/s which was the measured incipient tumbling velocity of the samples (3 in by 3 in by 1 in Cal-Sil, and 3 in by 3 in by 1/2 in Marinite).

• The spray flow for spray erosion testing was modeled on the CNP flow rates, nozzle size, and expected terminal velocity of the droplets." The Marinite flow erosion testing determined that after 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br />, the sample weight average loss was 1.18%." The Cal-Sil flow erosion testing determined that for a 720 hour0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> duration, the average weight loss was between 13.5% and 16.9%.* The dissolution tests for Cal-Sil resulted in a weight loss of between 1% and 5.5%. These values are bounded by the weight loss determined through the flow erosion testing.

Attachment 6 to AEP:NRC:8054-02 Page 13 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses Please discuss the treatment of LBLOCAs and A specific analysis for the generation of debris from a SBLOCA was small-break loss-of-coolant accident (SBLOCAs) in not performed.

The debris generation analysis, as described in the the debris generation analyses.

The staff SE on the response to Information Item 3.b, determined the debris generated alternate evaluation methodology defines a "debris from a DEGB of the largest RCS pipe and the DGBS that was generation break size" which distinguishes between equivalent in area to the double-ended rupture of the largest pipe customary and realistic design-basis analyses.

This attached to the RCS piping (14 in). The results of these breaks are methodology classifies all American Society of provided in the response to Information Item 3.b. The DGBS was Mechanical Engineers Boiler and Pressure Vessel treated as a LBLOCA. Both the DGBS and DEGB were treated in Code (ASME Code) Class 1 reactor coolant system traditional design basis analysis manner. Refer to the response to (RCS) attached piping, and breaks in the RCS main Information Items 3.b, 3.e, 3.f, and 3.o for additional discussion of the 37 loop piping equivalent to a double-ended guillotine treatment of these breaks.break (DEGB) of a 14-inch schedule 160 pipe as being analyzed using design-basis analyses.

The licensee identifies LBLOCAs as those greater than a 14-inch diameter pipe. It is not clear how the licensee is treating these breaks. For example, the DC Cook 14 inch diameter pressurizer surge line and 14 inch diameter residual heat removal (RHR)system cooldown pipe to RCS Loop No. 2 should be treated in a traditional design-basis analysis fashion. It is not clear that breaks in these lines were treated in this manner.The licensee states that for materials which have no The information on the applied ZOI radii is provided in the response to experimentally determined ZOI, a conservative Information Item 3.b. The only material for which a ZOI radius could assumption was made and the lowest available not be determined was assumed to fail, independent of a ZOI, in those 38 destruction pressure and ZOI were adopted (28.6 D). areas where breaks that could lead to recirculation could occur. That Please provide a listing of the materials for which this material was the PVC jackets on flexible conduit.ZOI was applied and the technical reasoning for concluding this is conservative.

Attachment 6 to AEP:NRC:8054-02 Page 14 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses It is not clear from the GL response how the Refer to the "Conclusion" section of the response to Information Item 3 alternate approach is being applied. Please provide for the discussion on the application of the alternate evaluation 39 a more detailed discussion of the approach taken. Is methodology.

The sump design was based on the limiting large break the proposed sump design based on the 14-inch case.debris generation break size or the limiting large-break case (Loop 4 cross-over break)?Please discuss any evaluations or considerations for I&M is not requesting exemptions as a result of applying the Alternate exemption requests as a result of applying the Break Methodology.

Section 6 methodology.

The NEI guidance report, 40 "Pressurized Water Reactor Sump Performance Evaluation Methodology," NEI 04-07, and associated NRC staff SE recognized that exemptions from the regulations may be needed if this methodology was applied.The licensee acknowledges that use of the alternate The information is provided in the response to Information Items 3.b, evaluation methodology requires that mitigative 3.e, 3.f, 3.o, and the "Conclusion" section of the response to capability be demonstrated for the Region II breaks Information Item 3. Refer also to the information contained in 41 (up through the DEGB of the largest RCS pipig). References 11, 12, and 14.The staff expects that the licensee will provide information to demonstrate this mitigative capability in their updated GL response.

Attachment 6 to AEP:NRC:8054-02 Page 15 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses 42 The September 2005 response to GL 2004-02 appears to indicate that, while the replacement strainer would be submerged, it would also be continuously vented to the containment atmosphere.

In this case, it is not clear to the staff whether a complete water seal would be preserved over the entire strainer surface if the head loss across the strainer were to exceed the vertical distance between the containment pool surface and the top of the vent pipe's connection to the strainer The September 2005 response stated that the maximum predicted head loss would be 8.17 ft (which was identified as possibly being overly conservative), and that analyzed containment water levels during the first 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> following an accident were identified as being in the range of 5, 9 -7.5 ft. Thus, it appears possible that, as a result of head loss across the suction strainer debris bed, the water level in the vent line could be drawn down to the point of uncovering a portion of the strainer surface. Without a complete water seal over its surface, the replacement strainer would no longer appear to meet the definition of a "fully submerged" sump in Appendix A to Regulatory Guide 1.82, Revision 3.Therefore, the NRC staff requests that the licensee provide further information concerning whether the potential exists for vent uncovery to break the water seal across the strainer surface. If this phenomenon is credible, please additionally state the criteria used to evaluate sumrn failure for this case.This information is provided in the response to Information Item 3.f. 11.

Attachment 6 to AEP:NRC:8054-02 Page 16 No. GL 2004-02 RAI Questions GL 2004-02 RAI Responses Has debris settling upstream of the sump strainer The information is provided in the response to Information Items 3.f.12 (i.e., the near-field effect) been credited or will it be and 3.o.1. I&M is not crediting near-field settling of debris upstream of credited in testing used to support the sizing or thd strainers.

analytical design basis of the proposed replacement strainers?

In the case that settling was credited for 43 either of these purposes, estimate the fraction of debris that settled and describe the analyses that were performed to correlate the scaled flow conditions and any surrogate debris in the test flume with the actual flow conditions and debris types in the plant's containment pool.What is the minimum strainer submergence during The information is provided in the response to Information Items 3.f. 1, the postulated LOCA? At the time that the re- 3.f.2, 3.f.3, and 3.j. Due to the design of the strainers at CNP, there is circulation starts, most of the strainer surface is not an entrance path for water or air on top of the strainers.

Buoyant expected to be clean, and the. strainer surface close debris on top of the remote strainer would not create a flow path for air to the pump suction line may experience higher fluid into the strainer due to the solid top plate on the strainer.flow than the rest of the strainer.

Has any analysis been done to evaluate the possibility of vortex formation close to the pump suction line and possible air ingestion into the ECCS pumps? In addition, has any analysis or test been performed to evaluate the possible accumulation of buoyant debris on top of the strainer, which may cause the formation of an air flow path directly through the strainer surface and reduce the effectiveness of the strainer?

ATTACHMENT 7 TO AEP:NRC:8054-02 REGULATORY COMMITMENTS The following table identifies those actions committed to by I&M in this letter. Any other actions discussed in this submittal represent intended or planned actions by I&M. They are described to the NRC for the NRC's information and are not regulatory commitments.

Commitment Date I&M will modify the insulation on the NESW lines inside the crane Prior to Unit 1 wall below the SG enclosures such that the foam insulation entry into Mode (Rubatex) is double jacketed without moisture barrier backing. 4 at the end of (Response to Information Items 3.b.3 and 3.i.1) the Spring 2008 RFO.I&M will provide the results of cold galvanizing compound testing Within 90 days of at K&L PPG in the final response to GL 2004-02. (Response to completion of all Information Item 3.b.3) actions needed to address GL 2004-02.I&M will complete removal of labels, tags, signs, tape, and similar Prior to Unit 1 materials to the extent practical in Unit 1, and will collect data for entry into Mode unqualified labels in Unit 1. (Response to Information Items 3.b.1, 4 at the end of 3.b.5 and 3.d.4) the Spring 2008 RFO.I&M will provide an update to this table (Table 3b5-1 Bounding Within 90 days of Quantity of Debris Available to Transport That Can Reduce completion of all Effective Strainer Area) with updated unit-specific values in the actions needed final response to GL 2004-02. (Response to Information Items to address GL 3.b.5 and 3.d.4) 2004-02.I&M will report on the analysis of water samples collected at Within 90 days of selected points during the large scale strainer testing in the final completion of all response to GL 2004-02. (Response to Information Item 3.f.4) actions needed to address GL 2004-02.I&M will perform sampling of latent debris in containment when Ongoing major work activities that could result in the generation of significant quantities of latent debris are performed, e.g., SG replacement. (Response to Information Item 3.i.1)in accordance with CNP procedures, commencing with the Unit 2 Ongoing Spring 2009 RFO, and for every Unit 1 and Unit 2 RFO thereafter, an assessment of containment debris sources will be completed.(Response to Information Item 3.i.1)

Attachment 7 to AEP:NRC:8054-02 Page 2 Commitment Date I&M will maintain the necessary programmatic and process Ongoing controls, such as those described in the response to Information Item 3.i.2, to ensure the ECCS and CTS recirculation functions are maintained in accordance with the applicable regulatory requirements identified in GL 2004-02.(Response to Information Item 3.i.2)I&M is continuing to evaluate station programs and processes to May 31, 2008 ensure the necessary controls to prevent the introduction of foreign material into containment will be in place prior to implementation of the new mechanistic design and licensing basis requirements that support resolution of GL 2004-02., I&M will implement any additional changes identified as necessary.(Response to Information Item 3.i.2)The evaluations of downstream effects within pumps, the reactor May 31, 2008 vessel, and the reactor core will be completed. (Response to Information Items 3.m.1 and 3.n.1)The results of the downstream effects analysis, including any Within 90 days of design or operational changes, will be provided in the final completion of all response to GL 2004-02. (Response to Information Items 3.m.2, actions needed 3.m.3, 3.n.1, 3.o.1, and 3.o.2) -to address GL 2004-02.I&M will provide the final determination of the impact of chemical Within 90 days of effects on strainer head loss considering the CCI testing and completion of all ALION testing in the final response to GL 2004-02. (Response to actions needed Information Items 3.o, 3.o.1, 3.o.14.a) and 3.o.14.b))

to address GL 2004-02.UFSAR Section 7.8 will be revised for Unit 1 following Prior to Unit 1 implementation of associated TS changes. (Response to entry into Mode Information Item 3.p) 4 at the end of the Spring 2008 RFO.I&M will change the licensing basis to reflect the mechanistic May 31, 2008 evaluation of the effect of post accident debris on the ECCS and CTS recirculation function. (Response to Information Item 3.p)

Attachment 7 to AEP:NRC:8054-02 Page 3 Commitment Date The changes to UFSAR Section 6.2, Section 6.3, Figure 6.2-1A, Prior to Unit 1 and Figure 9.3-1 to reflect installation of a new remote strainer in entry into Mode Unit 1 will be made effective. (Response to Information Item 3.p) 4 at the end of the Spring 2008 RFO.I&M will provide an update to the calculated NPSH margins Within 90 days of following completion of analysis associated with determination of completion of all head loss across the strainer, including chemical effects. actions needed (Response to Information Item 3.g.16) to address GL 12004-02.