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{{#Wiki_filter:INDIANA 8 NICHIGAN ELECTRIC COiMPANY P.O.BOX 16631 COLUMBUS, OHIO 43216 ItarCh 23, 1984 AEP:NRC:0860B Donald C.Cook Nuclear Plant Unit No.2 Docket No.50-316 License No.DPR-74 SUPPL1&EVZAL INFORMATION TO THE APPLICATION FOR UNIT 2 TECFKICAL SPECIFICATION CHAKZS FOR CYCLE 5 MLQAD Mr.Harold R.Denton, Director Office of Nuclear Reactor Regulation U.S.Nuclear Regulatory
{{#Wiki_filter:INDIANA 8 NICHIGAN ELECTRIC COiMPANY P.O. BOX 16631 COLUMBUS, OHIO 43216 ItarCh 23, 1984 AEP:NRC:0860B Donald C. Cook Nuclear Plant Unit No.       2 Docket No. 50-316 License No. DPR-74 SUPPL1&EVZAL INFORMATION TO THE APPLICATION FOR UNIT 2 TECFKICAL SPECIFICATION CHAKZS FOR CYCLE 5 MLQAD Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory     ~ssion Washington, D. C. 20555
~ssion Washington, D.C.20555  


==Dear Mr.Denton:==
==Dear Mr. Denton:==
The attachment to this letter provides responses to cpestions fran your staff which relate to the proposed change to Technical Specification (T/S)4.5.2.h.The proposed change was addressed in letters AEP:NRC:0860 (dated March 1, 1984)and AEP:NRC:0860A (dated March 15, 1984)and involved the flowrate for the flow balance test for the Safety Injection (SI)pumps.For consistency, a copy of this letter is being transmitted to the appropriate official of the State of Michigan.This docurrent has been prepared following Corporate procedures which incorporate a reasonable set of controls to insure its accuracy and ccepleteness prior to signature by the undersigned.
 
Very truly yours, M..Al'ch Vice P sident~-&MPA/pb Attachment cc: John E.Dolan W.G.Smith, Jr.-Bridgman R.C.Callen G.Charnoff E.R.Swanson, NRC Resident Inspector-Bridgman 8403270 i i 0" 840323 PDR ADOCK 050003ih PDR Mr.Harold R.AEP: NRC: 0860B ATTACHMXZ TO AEP:NRC: 0860B RESPCNSES TO NRC QU1HTICNS CONCERNING THE PROPOSED TtXHNICAL SPECIFICATION CFIRE IN FIXNRATE FOR THE SAFlKY INJZCTICN PUMPS FLCN BAIZCKE TEST Mr.Harold R.n AEP:NRC: 0860B QUESTION 1 Provide the safety injection flow delivered for each pump type in the original Unit 1 analysis and the Unit 1 analysis with the edification.
The attachment   to this letter provides responses to cpestions fran your staff which relate to the proposed change to Technical Specification (T/S) 4.5.2.h. The proposed change was addressed in letters AEP:NRC:0860 (dated March 1, 1984) and AEP:NRC:0860A (dated March 15, 1984) and involved the flowrate for the flow balance test for the Safety Injection (SI) pumps.
Re nse to Question 1: TABLE 1: CCNPARISCN OF SAFlKY INJ1ZTICN FLCN DELIVERH)TO THE RCS D.C.Cook Unit 1 Analysis 30 GEM Minif low&308 GPM Pump Runout RCS PRESSURE psia 14.7 114.7 140.7 214.7 414.7 614.7 814.7 1014.7 1214.7 1314.7 400 105.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 HHSI lb/sec 63.0 61.5 60.0 59.0 53.5 48.3 42.0 34.7 25.5 19.0 CHAlKING 1b/sec 47.7 45.8 45.0 44.0 40.0 36.0 31.6 27.2 22.7 20.5 TOl'AL lb/sec 510.7 213.2 105.0 103.0 93.5 84.3 73.6 61.9 48.2 39.5 D.C.Cook Unit 1 Analysis 60 GPM Pump Miniflow 6 300 GPM Pump Runout RCS PRESSURE psia 14.7 114.7 140.7 214.7 414.7 614.7 814.7 1014.7 1217.7 1314.7 400 105.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 HHSI lb/sec 61.6 59.1 58.3 56.6 51.1 45.4 39.0 31.8 22.7 16.1 CHARGING lb/sec 47.7 45.8 45.0 44.0 40.0 36.0 31.6 27.2 22.7 20.5 TOZAL lb/sec 509.3 210.8 103.3 100.5 91.1 81.4 70.6 59.0 45.4 36.6 NOZE: W has confirmed that the D.C.Cook Units 1 and 2 have tb sana SI flowrates.
For consistency, a copy of this letter is being transmitted to the appropriate official of the State of Michigan.
Mr.Harold R.n AEP: NRC: 0860B QUZSTICK 2 Provide the peak and average linear heat generation rate and the volurretric heat generation rate to support the applicability of the sensitivity study performed on Unit 1 to Unit 2.Res nse to Question 2: Provided belier are the peak and average linear heat generation rates for both D.C.Cook Units 1 and 2 LOCA analysis: Peak Linear Heat Generation Unit 1 16.67 kw/ft Unit 2 12.88 kw/ft Heat Generation 7.187 kw/ft 5.55 kw/ft Both plants were analyzed (current SBLCCA analyses)at 3411 MNt and an FQ=2.32.The actual Unit 2 peaking factor limit is less, since it is based on large break LOCA results.The difference in linear heat generation values is due to the different number of fuel rods between the two units.The higher peak values for D.C.Cook Unit 1 lead to higher heat-up rates and therefore application of the Unit 1 sensitivity study to Unit 2 is conservative.
This docurrent has been prepared following Corporate procedures which incorporate a reasonable set of controls to insure its accuracy and ccepleteness prior to signature by the undersigned.
The fuel design is the only major difference be~the two Units.Therefore, the following volunetric parameters are supplied, deaanstrating similarity in these paraneters between the two units and thus, the applicability of the Unit 2 sensitivity to the Unit 1 results.(1)Fuel Volumetric
Very   truly yours, M.   . Al 'ch Vice P sident       ~-&
=Total kw Heat Generation Total ft 3 for Total Core of Fuel Unit 1 3 988~7kw ft of Fuel Unit 2 98~35 kw ft of Fuel (2)Total Volume of Fluid in Core Region 614.8 ft 613.0 ft (1)Note-Volumetric heat generation per cubic feet of core fluid can be determined by the ratio (1)/(2)(2)Note-Since both units have 193 fuel assanblies and assuna an FQ=2.32 in their SBLOCA analyses, the oaap;u.ison of these parameters for the two plants for just the hot.assembly for both (1)and (2)would be similar.
MPA/pb Attachment cc:   John E. Dolan W. G. Smith,   Jr. Bridgman R. C. Callen G. Charnoff E. R. Swanson,   NRC   Resident Inspector Bridgman 8403270 ii0"050003ih PDR ADOCK 840323 PDR
Mr.Harold R.AEP:NRC: 0860B QUESTICN 3 Why does core recovery occur saner in the transient for the reduced HHSI case?Mmt causes the 86 F PCT penalty?Re nse to Question 3: A ccxoparison between the D.C.Cook Unit l base case analysis and the analysis with minif law modification (reduced HHSI flaw), was performed to determine the two times of core recovery.The follawing table surmarizes this comparison:
 
Reduced HHSI Time of minimum core mixture Hgt.(Core recovery due to acceaulator injection ccaaences beyond this time)793 sec 9 5.5'88 sec 9 5.0'im core mature level first recovers to elev.above top of active fuel.838 sec 848 sec Therefore, the first recovery of the core and turrmnund of the PCT is very similar between the two cases and in fact is slightly later for the reduced HHSI case.Note that the value for core recovery, in the sequence of events table (in appendix of additional results)of the reduced HHSI transrru.ttal, denotes the time of final core recovery and has no impact on PCT.Both analyses dermnstrate this behavior of subsequent core recovery due to intermittent accumulator injection.
Mr. Harold R.                                             AEP: NRC: 0860B ATTACHMXZ TO AEP:NRC: 0860B RESPCNSES TO NRC QU1HTICNS CONCERNING THE PROPOSED TtXHNICAL SPECIFICATION CFIRE IN FIXNRATE FOR THE SAFlKY INJZCTICN PUMPS FLCN BAIZCKE TEST
The PCT penalty of 86 F observed for the reduced HHSI case can be attributed to the lawer min~mm core mixture level and slower core recovery transient.
 
This is best observed by camparing the PCT plots for both cases.The reduced HHSI also has a slightly lawer core mixtxue level during the uncovery transient due to poor replenishment of boiloff in the core.Question 4: What is the reason for increasing the SI pump minif law?Re nse to Question 4: The increase frcxn 30 gpn to 60 gpn in mininMm recirculation flaw through the minif law orifice has been requested to reduce recirculation in the iapellers; to reduce the temperature rise through the pump when operating in the shutoff configuration; and to reduce the effect of any partial blockage that could be caused by a canponent malfunction.
Mr. Harold R.         n                                       AEP:NRC: 0860B QUESTION 1 Provide the safety injection flow delivered for each pump type in the original Unit 1 analysis and the Unit 1 analysis with the edification.
Although the existing 30 gpn minif law design is adequate, an increase to 60 gpn will inc+ease the safety margin for maintaining the pump integrity by reducing the tenperature rise through the pump and allowing another operation.
Re   nse to Question 1:
Mr.Harold R.AEP:NRC: 0860B Question 5: With exception of the respective cores, are the Zhergency Core Cooling Systems (ECCS)and the prism~systems the same for both Units 1 and 2?Re nse to Question 5: The Unit 1 and Unit 2 ECCS system ccaponents have essentially the sana flow characteristics.
TABLE   1: CCNPARISCN OF SAFlKY INJ1ZTICN FLCN DELIVERH) TO THE RCS D. C. Cook Unit 1 Analysis   30 GEM Miniflow & 308 GPM Pump Runout RCS PRESSURE                             HHSI          CHAlKING            TOl'AL psia                                 lb/sec          1b/sec          lb/sec
The Residual Heat Rermval, Safety Injection and Centrifugal Ch;~ing pumps;and the four Residual Heat EKchangers are each designed to the same specifications and operating conditions for both Units.All of re~ive parts of the pumps and heat exchangers are interchangeable.
: 14. 7               400              63.0            47.7             510. 7 114.7               105.9            61.5            45.8              213.2 140.7                  0.0           60. 0           45.0             105.0 214.7                  0.0           59.0           44.0             103.0 414.7                  0.0           53.5           40.0               93.5 614.7                   0.0           48.3            36.0               84.3 814.7                   0.0           42. 0           31.6              73.6 1014.7                  0.0          34.7            27.2              61.9 1214.7                  0.0          25. 5          22.7              48.2 1314.7                  0.0          19. 0          20.5              39.5 D. C. Cook   Unit 1 Analysis   60 GPM Pump Miniflow 6 300 GPM Pump Runout RCS PRESSURE                             HHSI          CHARGING          TOZAL psia                                 lb/sec          lb/sec          lb/sec
The other fluid path components for both Units are similar.The piping layouts for each Unit are syraetrical to each other (i.e., they have the same paths but one unit is essentially a mirror image of the other).Additionally, the safety injection pump and centrifugal charging pump discharge flow paths are balanced to the same technical specification values for both units by adjustment of valves in their flow paths.Question 6: What are the basic differences between Unit 1 and Unit 2?Re nse to Question 6: The differences in the non-Nuclear Steam Supply Systems (non-NSSS) for the two Units are described in the FSAR, Chapter 10.In essence, the Unit 1 non-NSSS design is consistent with the General Electric turbine design and the Unit 2 non-NSSS design is consistent with the Brown Boveri turbine design.The differences in the Reactor and the Reactor Coolant System operating param ters for both units are listed in the FSAR Chapters 3 and 4.However, we note that the Westinghouse evaluation which was done in support of the proposed T/S change was performed using 3411 MWt instead of 3250 MWt.The following are differences be~the Unit 1 and Unit 2 cores: a.Unit 1 has 15X15 fuel assemblies.
: 14. 7               400              61.6            47. 7           509. 3 114. 7               105.9            59.1            45.8            210.8 140. 7                 0.0           58.3            45.0             103.3 214. 7                  0.0           56.6            44.0             100.5 414.7                  0.0           51.1            40.0               91. 1 614.7                  0.0           45.4            36.0               81.4 814.7                  0.0          39.0            31. 6             70.6 1014.7                  0.0           31.8           27. 2              59.0 1217.7                   0.0          22.7            22. 7             45.4 1314.7                  0.0           16.1            20.5              36.6 NOZE:    W has confirmed  that the D. C. Cook  Units 1 and 2 have  tb  sana SI flowrates.
Unit 2 has 17X17 fuel assemblies.
 
b.Unit 1 fuel has 7 grid straps along the~lenc~of the fuel assemblies.
Mr. Harold R.         n                                        AEP: NRC: 0860B QUZSTICK 2 Provide the peak and average linear heat generation rate and the volurretric heat generation rate to support the applicability of the sensitivity study performed on Unit 1 to Unit 2.
(1)'Ihe 113 Exxon fuel assemblies have Zircaloy straps which are 2.25 inches high, with Inconel springs.(2)The 80 Westinghouse fuel assemblies have top and bottcxn Inconel straps which are 1.5 inches high.The five middle straps are made of Zircaloy and are 2.25 inches high.Unit 2 fuel has 8 grid straps along the axial length of the fuel assemblies.
Res  nse  to Question 2:
(1)She 164 Exxon fuel assemblies have 2.5 inch Zircaloy straps with Inconel springs.(2)Ghe 29 Westinghouse fuel assemblies have Inconel straps which are 1.32 inches high.
Provided belier are the peak and average linear heat generation rates          for both D. C. Cook Units 1 and 2 LOCA analysis:
Mr.Harold R.AEP:NRC: 0860B c.The Unit 1 fuel rods have a larger outside diam ter than Unit 2, as indicated below: Unit 1 Unit 2 Exxon fuel 5 of assemblies Outside Dianeter 113.424" 164.360" Westin house fuel I of assemblies 80 29 Outside Diaster.422".374" The Unit 1 guide tubes/instrurreatation tubes have a larger outside dianeter than Unit 2, as indicated below: Unit 1 Unit 2 Exxon fuel I of assemblies 164 Outside Dianeter.480" I of assemblies 80 Outside assemblies
Unit  1                      Unit  2 Peak  Linear Heat Generation                        16.67  kw/ft                12.88  kw/ft Heat Generation                          7.187  kw/ft                5.55  kw/ft Both plants were analyzed (current SBLCCA analyses) at 3411 MNt and an FQ=2.32. The actual Unit 2 peaking factor limit is less, since based on large break LOCA results. The difference in linear heat it  is generation values is due to the different number of fuel rods between the two units. The higher peak values for D. C. Cook Unit 1 lead to higher heat-up rates and therefore application of the Unit        1  sensitivity study to Unit 2 is conservative.
.533" 29.482" e.Both cores have Ag-In~control rods.Both cores have 53 Rod Control Cluster Assemblies (ROC').Unit 1 has 20 rods per RCCA and Unit 2 has 24 rods per RCCA.Unit 1 has Mt Annular Burnable Assorbers (WhBA)for burnable poisons: Annular B C.A1 0 pellets, clad in Zircaloy, with H20 in the midcLle.Unit 2 has solid B4C A1203 pellets, clad in Zircaloy, for burnable poisons.g The following are the respective flowrates (mass)for the Units: Unit 1 (3250 NÃt)135.6 X 106 lbs/hr.Unit 1 (3411 NNt)138.6 X 106 lbs/hr.Unit 2 (3411 MÃt)142.7 X 10 lbs/hr.h.Unit 1 (3250)Unit 1 (3411)Unit 2 (3411)536.3 545.5 543.1 The following are the respective inlet'empexatures for the Units: F avg'67.8 577.1 574.1 i.The ncxninal pressure for both Units is 2250 psia.j.The following are the best estimates for the respective pressure drops across the core during normal operations.
The  fuel design is the only major difference      be~    the two Units.
Unit 1 (3250)Unit 1 (3411)Unit 2 (3411)22.4 p ia 27.15 psia 24.5 psia}}
Therefore, the following volunetric parameters are supplied, deaanstrating similarity in these paraneters between the two units and thus, the applicability of the Unit 2 sensitivity to the Unit 1 results.
Unit  1            Unit  2 (1) Fuel Volumetric = Total kw3          988~7kw  ft3        98~35  kw ft Heat Generation     Total ft               of Fuel              of Fuel for Total Core        of Fuel (2) Total Volume of                      614.8  ft          613.0  ft Fluid in Core Region (1)  Note  Volumetric heat generation per cubic      feet of core fluid can be determined by the ratio (1) /(2)
(2)  Note  Since both  units have 193  fuel assanblies and assuna an FQ=2.32  in their SBLOCA analyses, the oaap;u.ison of these parameters  for the two plants  for just the  hot. assembly    for both (1) and (2) would be similar.
 
Mr. Harold R.                                               AEP:NRC: 0860B QUESTICN 3 Why  does core recovery occur saner in the transient    for the reduced HHSI case?    Mmt causes the 86 F PCT penalty?
Re    nse  to Question 3:
A ccxoparison between                        l the D. C. Cook Unit base case analysis and the analysis with miniflaw modification (reduced HHSI flaw), was performed to determine the two times of core recovery. The follawing table surmarizes  this comparison:
Time  of minimum  core mixture Hgt. (Core recovery due to acceaulator injection ccaaences 5.
5'88 793 sec  9 Reduced HHSI 5.
sec  9 beyond this time)                                                    0'im core mature level first              838 sec            848 sec recovers to elev. above top of active fuel.
Therefore, the first recovery of the core and turrmnund of the PCT is very similar between the two cases and in fact is slightly later for the reduced HHSI case. Note that the value for core recovery, in the sequence of events table (in appendix of additional results) of the reduced HHSI transrru.ttal, denotes the time of final core recovery and has no impact on PCT. Both analyses dermnstrate this behavior of subsequent core recovery due to intermittent accumulator injection.
The PCT  penalty of 86 F observed for the reduced HHSI case can be attributed to the lawer min~mm core mixture level and slower core recovery transient. This is best observed by camparing the PCT plots for both cases. The reduced HHSI also has a slightly lawer core mixtxue level during the uncovery transient due to poor replenishment of boiloff in the core.
Question 4:    What  is the reason  for increasing the SI pump  miniflaw?
Re    nse  to Question 4:
The  increase frcxn  30 gpn to 60 gpn in mininMm recirculation flaw through the miniflaw  orifice  has been  requested to reduce recirculation in the iapellers; to reduce the temperature rise through the pump when operating in the shutoff configuration; and to reduce the effect of any partial blockage that could be caused by a canponent malfunction.
Although the existing 30 gpn miniflaw design is adequate, an increase to 60 gpn will inc+ease the safety margin for maintaining the pump integrity by reducing the tenperature rise through the pump and allowing another operation.
 
Mr. Harold R.                                                   AEP:NRC: 0860B Question 5: With exception of the respective cores, are the Zhergency Core Cooling Systems (ECCS) and the prism~ systems the same for both Units  1 and 2?
Re    nse  to Question 5:
The Unit 1 and Unit 2 ECCS system ccaponents have essentially the sana flow characteristics. The Residual Heat Rermval, Safety Injection and Centrifugal Ch;~ing pumps; and the four Residual Heat EKchangers are each designed to the same specifications and operating conditions for both Units. All of      re~ive      parts of the pumps and heat exchangers are interchangeable.      The other fluid path components for both Units are similar. The piping layouts for each Unit are syraetrical to each other (i.e., they have the same paths but one unit is essentially a mirror image of the other) . Additionally, the safety injection pump and centrifugal charging pump discharge flow paths are balanced to the same technical specification values for both units by adjustment of valves in their flow paths.
Question 6:      What are  the basic differences between Unit    1  and Unit 2?
Re    nse  to Question    6:
The  differences in the non-Nuclear Steam Supply Systems (non-NSSS) for the two Units are described in the FSAR, Chapter 10. In essence, the Unit 1 non-NSSS design is consistent with the General Electric turbine design and the Unit 2 non-NSSS design is consistent with the Brown Boveri turbine design.
The differences in the Reactor and the Reactor Coolant System operating param ters for both units are listed in the FSAR Chapters 3 and 4.
However, we note that the Westinghouse evaluation which was done in support of the proposed T/S change was performed using 3411 MWt instead of 3250 MWt.
The following are differences      be~     the Unit 1 and Unit  2  cores:
: a. Unit  1  has 15X15  fuel assemblies.
b.
Unit  2  has 17X17 Unit 1 fuel has fuel assemblies.
(1) 7 fuel assemblies.
grid straps along the ~    lenc~ of the
                  'Ihe 113 Exxon fuel assemblies have Zircaloy straps which are 2.25 inches high, with Inconel springs.
(2)  The 80 Westinghouse fuel assemblies have top and bottcxn Inconel straps which are 1.5 inches high. The five middle straps are made of Zircaloy and are 2.25 inches high.
Unit 2 fuel has    8  grid straps along the axial length of the fuel assemblies.
(1)  She 164 Exxon fuel assemblies have 2.5 inch Zircaloy straps with Inconel springs.
(2)  Ghe 29 Westinghouse fuel assemblies have Inconel straps which are 1.32 inches high.
 
Mr. Harold R.                                                          AEP:NRC: 0860B
: c. The  Unit 1 fuel rods have a        larger outside diam ter than Unit 2, as  indicated below:
Unit   1                Unit  2 Exxon    fuel 5  of assemblies           113                    164 Outside Dianeter          .424"                  .360" Westin house fuel I of assemblies             80                      29 Outside Diaster            . 422"                  . 374" The Unit 1 guide tubes/instrurreatation tubes have a larger outside dianeter than Unit 2, as indicated below:
Unit 1                    Unit 2 Exxon   fuel I of assemblies                                     164 Outside Dianeter                                    .480" I of assemblies              80                       29 Outside assemblies         . 533"                    .482"
: e. Both cores have      Ag-In~ control rods. Both cores have 53 Rod Control Cluster Assemblies (ROC'). Unit 1 has 20 rods per RCCA and Unit 2 has 24 rods per RCCA.
Unit  1  has  Mt Annular Burnable Assorbers        (WhBA) for burnable poisons:      Annular B C.A1 0 pellets, clad        in Zircaloy, with H20 in the midcLle.
Unit  2 has    solid  B4C A1203  pellets, clad in Zircaloy, for burnable poisons.
g    The following are the respective flowrates            (mass)  for the Units:
Unit 1 (3250 NÃt)              135.6 X  106 lbs/hr.
Unit 1 (3411 NNt)              138.6 X  106 lbs/hr.
Unit 2 (3411 MÃt)              142.7 X  10 lbs/hr.
: h. The  following are the respectiveinlet'empexatures for the Units:
F avg'67.8 Unit    1  (3250)         536.3 Unit   1  (3411)          545. 5            577.1 Unit   2 (3411)         543. 1            574.1
: i. The ncxninal pressure      for both Units is 2250 psia.
: j. The   following are the best estimates for the respective pressure drops across the core during normal operations.
Unit    1  (3250)       22.4 p ia Unit   1 (3411)       27.15 psia Unit   2 (3411)         24.5 psia}}

Latest revision as of 12:52, 22 October 2019

Forwards Responses to NRC Questions Re Proposed 840301 & 15 Tech Spec Change Requests to Flow Rate for Safety Injection Pump Flow Balance Test.Info Constitutes Supplemental Info for Changes to Cycle 5 Reload
ML17334A519
Person / Time
Site: Cook American Electric Power icon.png
Issue date: 03/23/1984
From: Alexich M
INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To: Harold Denton
Office of Nuclear Reactor Regulation
References
AEP:NRC:0860B, AEP:NRC:860B, NUDOCS 8403270110
Download: ML17334A519 (7)
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Text

INDIANA 8 NICHIGAN ELECTRIC COiMPANY P.O. BOX 16631 COLUMBUS, OHIO 43216 ItarCh 23, 1984 AEP:NRC:0860B Donald C. Cook Nuclear Plant Unit No. 2 Docket No. 50-316 License No. DPR-74 SUPPL1&EVZAL INFORMATION TO THE APPLICATION FOR UNIT 2 TECFKICAL SPECIFICATION CHAKZS FOR CYCLE 5 MLQAD Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory ~ssion Washington, D. C. 20555

Dear Mr. Denton:

The attachment to this letter provides responses to cpestions fran your staff which relate to the proposed change to Technical Specification (T/S) 4.5.2.h. The proposed change was addressed in letters AEP:NRC:0860 (dated March 1, 1984) and AEP:NRC:0860A (dated March 15, 1984) and involved the flowrate for the flow balance test for the Safety Injection (SI) pumps.

For consistency, a copy of this letter is being transmitted to the appropriate official of the State of Michigan.

This docurrent has been prepared following Corporate procedures which incorporate a reasonable set of controls to insure its accuracy and ccepleteness prior to signature by the undersigned.

Very truly yours, M. . Al 'ch Vice P sident ~-&

MPA/pb Attachment cc: John E. Dolan W. G. Smith, Jr. Bridgman R. C. Callen G. Charnoff E. R. Swanson, NRC Resident Inspector Bridgman 8403270 ii0"050003ih PDR ADOCK 840323 PDR

Mr. Harold R. AEP: NRC: 0860B ATTACHMXZ TO AEP:NRC: 0860B RESPCNSES TO NRC QU1HTICNS CONCERNING THE PROPOSED TtXHNICAL SPECIFICATION CFIRE IN FIXNRATE FOR THE SAFlKY INJZCTICN PUMPS FLCN BAIZCKE TEST

Mr. Harold R. n AEP:NRC: 0860B QUESTION 1 Provide the safety injection flow delivered for each pump type in the original Unit 1 analysis and the Unit 1 analysis with the edification.

Re nse to Question 1:

TABLE 1: CCNPARISCN OF SAFlKY INJ1ZTICN FLCN DELIVERH) TO THE RCS D. C. Cook Unit 1 Analysis 30 GEM Miniflow & 308 GPM Pump Runout RCS PRESSURE HHSI CHAlKING TOl'AL psia lb/sec 1b/sec lb/sec

14. 7 400 63.0 47.7 510. 7 114.7 105.9 61.5 45.8 213.2 140.7 0.0 60. 0 45.0 105.0 214.7 0.0 59.0 44.0 103.0 414.7 0.0 53.5 40.0 93.5 614.7 0.0 48.3 36.0 84.3 814.7 0.0 42. 0 31.6 73.6 1014.7 0.0 34.7 27.2 61.9 1214.7 0.0 25. 5 22.7 48.2 1314.7 0.0 19. 0 20.5 39.5 D. C. Cook Unit 1 Analysis 60 GPM Pump Miniflow 6 300 GPM Pump Runout RCS PRESSURE HHSI CHARGING TOZAL psia lb/sec lb/sec lb/sec
14. 7 400 61.6 47. 7 509. 3 114. 7 105.9 59.1 45.8 210.8 140. 7 0.0 58.3 45.0 103.3 214. 7 0.0 56.6 44.0 100.5 414.7 0.0 51.1 40.0 91. 1 614.7 0.0 45.4 36.0 81.4 814.7 0.0 39.0 31. 6 70.6 1014.7 0.0 31.8 27. 2 59.0 1217.7 0.0 22.7 22. 7 45.4 1314.7 0.0 16.1 20.5 36.6 NOZE: W has confirmed that the D. C. Cook Units 1 and 2 have tb sana SI flowrates.

Mr. Harold R. n AEP: NRC: 0860B QUZSTICK 2 Provide the peak and average linear heat generation rate and the volurretric heat generation rate to support the applicability of the sensitivity study performed on Unit 1 to Unit 2.

Res nse to Question 2:

Provided belier are the peak and average linear heat generation rates for both D. C. Cook Units 1 and 2 LOCA analysis:

Unit 1 Unit 2 Peak Linear Heat Generation 16.67 kw/ft 12.88 kw/ft Heat Generation 7.187 kw/ft 5.55 kw/ft Both plants were analyzed (current SBLCCA analyses) at 3411 MNt and an FQ=2.32. The actual Unit 2 peaking factor limit is less, since based on large break LOCA results. The difference in linear heat it is generation values is due to the different number of fuel rods between the two units. The higher peak values for D. C. Cook Unit 1 lead to higher heat-up rates and therefore application of the Unit 1 sensitivity study to Unit 2 is conservative.

The fuel design is the only major difference be~ the two Units.

Therefore, the following volunetric parameters are supplied, deaanstrating similarity in these paraneters between the two units and thus, the applicability of the Unit 2 sensitivity to the Unit 1 results.

Unit 1 Unit 2 (1) Fuel Volumetric = Total kw3 988~7kw ft3 98~35 kw ft Heat Generation Total ft of Fuel of Fuel for Total Core of Fuel (2) Total Volume of 614.8 ft 613.0 ft Fluid in Core Region (1) Note Volumetric heat generation per cubic feet of core fluid can be determined by the ratio (1) /(2)

(2) Note Since both units have 193 fuel assanblies and assuna an FQ=2.32 in their SBLOCA analyses, the oaap;u.ison of these parameters for the two plants for just the hot. assembly for both (1) and (2) would be similar.

Mr. Harold R. AEP:NRC: 0860B QUESTICN 3 Why does core recovery occur saner in the transient for the reduced HHSI case? Mmt causes the 86 F PCT penalty?

Re nse to Question 3:

A ccxoparison between l the D. C. Cook Unit base case analysis and the analysis with miniflaw modification (reduced HHSI flaw), was performed to determine the two times of core recovery. The follawing table surmarizes this comparison:

Time of minimum core mixture Hgt. (Core recovery due to acceaulator injection ccaaences 5.

5'88 793 sec 9 Reduced HHSI 5.

sec 9 beyond this time) 0'im core mature level first 838 sec 848 sec recovers to elev. above top of active fuel.

Therefore, the first recovery of the core and turrmnund of the PCT is very similar between the two cases and in fact is slightly later for the reduced HHSI case. Note that the value for core recovery, in the sequence of events table (in appendix of additional results) of the reduced HHSI transrru.ttal, denotes the time of final core recovery and has no impact on PCT. Both analyses dermnstrate this behavior of subsequent core recovery due to intermittent accumulator injection.

The PCT penalty of 86 F observed for the reduced HHSI case can be attributed to the lawer min~mm core mixture level and slower core recovery transient. This is best observed by camparing the PCT plots for both cases. The reduced HHSI also has a slightly lawer core mixtxue level during the uncovery transient due to poor replenishment of boiloff in the core.

Question 4: What is the reason for increasing the SI pump miniflaw?

Re nse to Question 4:

The increase frcxn 30 gpn to 60 gpn in mininMm recirculation flaw through the miniflaw orifice has been requested to reduce recirculation in the iapellers; to reduce the temperature rise through the pump when operating in the shutoff configuration; and to reduce the effect of any partial blockage that could be caused by a canponent malfunction.

Although the existing 30 gpn miniflaw design is adequate, an increase to 60 gpn will inc+ease the safety margin for maintaining the pump integrity by reducing the tenperature rise through the pump and allowing another operation.

Mr. Harold R. AEP:NRC: 0860B Question 5: With exception of the respective cores, are the Zhergency Core Cooling Systems (ECCS) and the prism~ systems the same for both Units 1 and 2?

Re nse to Question 5:

The Unit 1 and Unit 2 ECCS system ccaponents have essentially the sana flow characteristics. The Residual Heat Rermval, Safety Injection and Centrifugal Ch;~ing pumps; and the four Residual Heat EKchangers are each designed to the same specifications and operating conditions for both Units. All of re~ive parts of the pumps and heat exchangers are interchangeable. The other fluid path components for both Units are similar. The piping layouts for each Unit are syraetrical to each other (i.e., they have the same paths but one unit is essentially a mirror image of the other) . Additionally, the safety injection pump and centrifugal charging pump discharge flow paths are balanced to the same technical specification values for both units by adjustment of valves in their flow paths.

Question 6: What are the basic differences between Unit 1 and Unit 2?

Re nse to Question 6:

The differences in the non-Nuclear Steam Supply Systems (non-NSSS) for the two Units are described in the FSAR, Chapter 10. In essence, the Unit 1 non-NSSS design is consistent with the General Electric turbine design and the Unit 2 non-NSSS design is consistent with the Brown Boveri turbine design.

The differences in the Reactor and the Reactor Coolant System operating param ters for both units are listed in the FSAR Chapters 3 and 4.

However, we note that the Westinghouse evaluation which was done in support of the proposed T/S change was performed using 3411 MWt instead of 3250 MWt.

The following are differences be~ the Unit 1 and Unit 2 cores:

a. Unit 1 has 15X15 fuel assemblies.

b.

Unit 2 has 17X17 Unit 1 fuel has fuel assemblies.

(1) 7 fuel assemblies.

grid straps along the ~ lenc~ of the

'Ihe 113 Exxon fuel assemblies have Zircaloy straps which are 2.25 inches high, with Inconel springs.

(2) The 80 Westinghouse fuel assemblies have top and bottcxn Inconel straps which are 1.5 inches high. The five middle straps are made of Zircaloy and are 2.25 inches high.

Unit 2 fuel has 8 grid straps along the axial length of the fuel assemblies.

(1) She 164 Exxon fuel assemblies have 2.5 inch Zircaloy straps with Inconel springs.

(2) Ghe 29 Westinghouse fuel assemblies have Inconel straps which are 1.32 inches high.

Mr. Harold R. AEP:NRC: 0860B

c. The Unit 1 fuel rods have a larger outside diam ter than Unit 2, as indicated below:

Unit 1 Unit 2 Exxon fuel 5 of assemblies 113 164 Outside Dianeter .424" .360" Westin house fuel I of assemblies 80 29 Outside Diaster . 422" . 374" The Unit 1 guide tubes/instrurreatation tubes have a larger outside dianeter than Unit 2, as indicated below:

Unit 1 Unit 2 Exxon fuel I of assemblies 164 Outside Dianeter .480" I of assemblies 80 29 Outside assemblies . 533" .482"

e. Both cores have Ag-In~ control rods. Both cores have 53 Rod Control Cluster Assemblies (ROC'). Unit 1 has 20 rods per RCCA and Unit 2 has 24 rods per RCCA.

Unit 1 has Mt Annular Burnable Assorbers (WhBA) for burnable poisons: Annular B C.A1 0 pellets, clad in Zircaloy, with H20 in the midcLle.

Unit 2 has solid B4C A1203 pellets, clad in Zircaloy, for burnable poisons.

g The following are the respective flowrates (mass) for the Units:

Unit 1 (3250 NÃt) 135.6 X 106 lbs/hr.

Unit 1 (3411 NNt) 138.6 X 106 lbs/hr.

Unit 2 (3411 MÃt) 142.7 X 10 lbs/hr.

h. The following are the respectiveinlet'empexatures for the Units:

F avg'67.8 Unit 1 (3250) 536.3 Unit 1 (3411) 545. 5 577.1 Unit 2 (3411) 543. 1 574.1

i. The ncxninal pressure for both Units is 2250 psia.
j. The following are the best estimates for the respective pressure drops across the core during normal operations.

Unit 1 (3250) 22.4 p ia Unit 1 (3411) 27.15 psia Unit 2 (3411) 24.5 psia

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