ML17334B584

Provides Info Requested in NRC Bulletin 96-001, Control Rod Insertion Problems

ML17334B584
Person / Time
Site:	Cook
Issue date:	04/08/1996
From:	Fitzpatrick E INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
AEP:NRC:1249, IEB-96-001, IEB-96-1, NUDOCS 9604100083
Download: ML17334B584 (45)

Text

Indiana Michigan Power Company P.O. Box 16631 Coiumbus, OH 43216 April 8, 1996 AEP:NRC:1249 Docket Nos.:

50-315 50-316 U.

S. Nuclear Regulatory Commission ATTN:

Document Control Desk Washington, D.

C.

20555 Gentlemen:

Donald C.

Cook Nuclear Plant Units 1 and 2

NRC BULLETIN 96-01:

CONTROL ROD INSERTION PROBLEMS The purpose of this letter is to provide information requested in NRC Bulletin 96-01.

NRC Bulletin 96-01 was sent to all holders of pressurized water reactor (PWR) operating licenses to alert them to problems encountered during recent events in which control rods failed to completely insert upon a scram signal and to request an assessment of the operability of control rods, particularly in high burnup fuel assemblies'onald C.

Cook Nuclear Plant Unit 1 is currently operating in its fifteenth fuel cycle, and Unit 2 is shut down for refueling after its tenth fuel cycle.

Our response to the NRC Bulletin is contained in the attachments.

Our response to NRC Bulletin 96-01 was requested to be made under oath or affirmation according to the provisions of Section 182a of the Atomic Energy Act of 1954, as amended, and 10 CFR 50.54(f).

As

such, an oath statement is included with this letter.

Sincerely, SWORN TO AND SUBSCRIBED BEFORE ME EP E.

E. Fitzpatrick Vice President THIS~

DAY OF Notary Public 1996 Attachments

(

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'&0408 PDR j )'ADOCK 05000315 8

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U.

S. Nuclear Regulatory Commission Page 2

AEP:NRC:1249 CC:

A. A. Blind G. Charnoff H. J. Miller - Region IIIAdministrator NFEM Section Chief NRC Resident Inspector

- Bridgman J.

R. Padgett

ATTACHMENT 1 TO AEP:NRC'1249 REQUESTED ACTIONS AND INFORMATION IN NRC BULLETIN 96-01

ATTACHMENT 1 TO AEP:NRC:1249 PAGE 1 Bulletin 96-01 Re uested Actions and Information To ensure that the required shutdown margin is maintained during a reactor trip, all licensees of Westinghouse-designed plants were requested to take the following actions.

(1)

Promptly inform operators of recent events in which control rods did not fully insert and subsequently provide necessary training, including simulator drills, utilizing the required procedures for responding to an event in which the control rods do not fully insert upon reactor trip.

(2)

Promptly determine the continued operability of control rods based on current information, (3)

Measure and evaluate at each outage of sufficient duration during calendar year 1996, the control rod drop times and rod recoil data for all control rods.

If appropriate plant conditions exist where the vessel head is removed, measure and evaluate drag forces for all rodded fuel assemblies.

(4)

For each reactor trip during calendar year 1996, verify that all control rods have promptly fully inserted and obtain other available information to assess the operability and any performance trend of the rods.

In the event that all rods do not fully insert

promptly, conduct tests to measure and evaluate rod drop times and rod recoil.

This Bulletin required Westinghouse-designed plants to submit the following written information.

(1)

Within 30 days of the date of this Bulletin, a report certifying that control rods are determined to be operable; actions taken for Requested Actions (1) and (2) above; and the plans for implementing Requested Action (3) and (4).

This information is contained in Attachment 2, (2)

Within 30 days of the date of this Bulletin, a core map of rodded fuel assemblies indicating fuel type (materials,

grids, spacers, guide tube inner diameter) and current and pro]ected end of cycle burnup of each rodded assembly for the current cycle; when available, provide the same information for the next cycle.

This information is contained in Attachment 3.

ATTACHMENT 1 TO AEP'NRC'1249 PAGE 2 (3)

Within 30 days after completing Requested Action (3) for each

outage, a report that summarizes the data and that documents the results obtained.

This information is contained in Attachment 4.

ATTACHMENT 2 TO AEP:NRC'1249 NRC BULLETIN 96-01

RESPONSE

NO.

1

ATTACHMENT 2 TO AEP:NRC:1249 PAGE 1 Res onse No.

1 Action 1 - Trainin Cook Nuclear Plant training department personnel met with shift supervisors on March 20,

1996, to discuss the subject Bulletin's Action Item 1.

The shift supervisors indicated that all licensed operators were aware of the most recent issues related to rod drop problems with Westinghouse fuel.

They further indicated that operators were capable of taking the appropriate actions set forth in our existing emergency operating procedures for a multiple stuck rod situation.

As far as simulator training is concerned, a scenario will be developed by April 15, 1996.

This will provide the operators the opportunity to practice pose-trip stuck rod events.

The training is scheduled to be completed by the end of the current Unit 2

refueling outage.

Action 2 - 0 erabilit Determination A control rod operability determination was performed on March 21, 1996.

This review concluded that, based on available information, the control rods for Cook Nuclear Plant Units 1 and 2 are operable and can perform their intended functions of shutting down the reactor from 100/ power and keeping the reactor subcritical at hot conditions.

This conclusion was based on the following points that apply to both units:

(2)

(4)

(5)

(6) excess Shutdown Margin is available to accommodate a number of RCCAs not fully inserting; control rod operability testing, as required by the technical specifications, assures that the CRDMs are performing properly; past trips indicate full insertion of rods based on Analog Rod Position Indication (ARPI) system readings'nd rod bottom lights (some initial indications of incomplete insertion have occured in the past but have all been resolved after further investigation);

beginning of cycle rod drop and drag test data have shown no abnormalities in rod insertion; the CVCS boron injection system is available as a backup for negative reactivity insertion; and data gathered by Westinghouse show no control rod problems in the majority of plants.

ATTACHMENT 2 TO AEP:NRC:1249 PAGE 2 Action 3 - Control Rod Tests Cook Nuclear Plant Unit 2 was shut down for refueling on March 23, 1996.

Shut down was accomplished, by tripping from approximately 20X Rated Thermal Power.

All rods fully inserted as expected during the trip ~

Rod drop tests were conducted at hot conditions to determine the behavior of the RCCAs in a simulated trip.

A plot of induced voltage, due to rod movement, and rod drop time was obtained for each RCCA.

The traces also show any "bounce" due to an RCCA hub assembly hitting the top of the fuel assembly and any subsequent RCCA bounce due to the spring in the RCCA assembly. It should be noted that the technique used on March 23 for measuring rod drop time was changed from that used at the beginning of cycle test to allow for multiple rod drop.

The trip breaker, served as the initiation signal in the new system as compared to pulling the stationary gripper coil fuse in the old system.

Due to this, the rod drop times are slightly increased (0.1 sec.

- 0.15 sec.) for all RCCAs from the previous beginning of cycle results.

Analysis of the traces indicated that all rods inserted completely and the drop times were well within the technical specification limit of 2.7

seconds, The slowest measured rod was in core location H-14 at 1.589 seconds and the fastest was in core location M-12 at 1.395 seconds.

All rods exhibited similar traces as the beginning of cycle traces including the "bounce".

Since the rod drop test did not show any abnormality, drag testing was not conducted.

This had been previously discussed with the NRC staff on March 18, 1996.

Based on the information from the Unit 1 trip that is described in Action 4 below and the Unit 2 rod drop test, it is our conclusi.on that the phenomena that have occurred at South Texas and Wolf Creek are not being seen at Cook Nuclear Plant.

As a result we will perform rod drop testing for pre-planned outages (where the reactor is shutdown) of five days or longer during calendar year 1996.

We believe that a five day outage is an "outage of sufficient duration" considering the time to establish the proper system conditions and set up the necessary equipment without adversely affecting critical path for restart.

Also, regarding the minimum interval betweeri testing, data will be collected for trips that occur after a burnup interval of greater than 2500 MWD/MTU since the previous trip unless the trip data indicates abnormal control rod behavior.

This is consistent with a verbal NRC staff agreement during a meeting with the Westinghouse Owners Group Issues Review Group on March 25, 1996.

As usual, the beginning of cycle rod drop test and drag test willbe performed before the Unit 2 cycle start-up.

It should be noted that no other refueling outages are scheduled for the remainder of 1996.

ATTACHMENT 2 TO AEP:NRC:1249 PAGE 3

We will continue to follow industry experience in this area and the Westinghouse root cause analysis and will modify our plans as necessary.

Action 4 - Reactor Tr Cook Nuclear Plant Unit. 1 tripped on March 17, 1996.

Control room operators confirmed immediate rod bottom light activation and full insertion of the RCCAs.

As is our practice, verification will continue to be performed for each reactor trip to assure that all rods insert fully without delay.

In the event that all rods do not fully insert promptly, tests will be conducted to measure and evaluate rod drop time and rod "bounces."

ATTACHMENT 3 TO AEP:NRC:1249 NRC BULLETIN 96-01

RESPONSE

NO.

2

ATTACHMENT 3 TO AEP:NRC:1249 PAGE 1 R~es ense 2

Fuel type information and a

core map indicating the rodded assemblies are provided on the following pages for Units 1 and 2.

Also, burnup information for the following is provided:

(1)

(2)

(3)

(4)

(5)

Unit 1, Cycle 15 Unit 1, Cycle 15 Unit 1, Cycle 15 Unit 2, Cycle 10 Unit 2, Cycle 10 beginning of cycle burnup current burnup as of March 27, 1996 projected end-of-cycle burnup beginning of cycle burnup end-of-cycle burnup Assembly burnup information transmitted at a later time.

for Unit 2,

Cycle 11 will be

ATTACHMENT 3 TO AEP'NRC:1249 PAGE 2 Donald C.

Cook Nuclear Plant U~nie Fuel T e Informatio Fuel Type Core Power Cycle 15 Length 15 x 15 OFA 3250 MWz 425 EFPD Fuel 'Rod Data Fuel Material Clad Material Clad Outer Diameter UO~

Zircaloy-4 0.422" II.

RCCA Data RCCA Absorber Material RCCA Clad Material RCCA Clad Outer Diameter Ag-In-Cd SS-304 0.439" III.

Guide Thimble GT Data GT Material GT Inner Diameter (above dashpot)

(at dashpot)

Zircaloy-4 0.499" 0.455" IV.

Grid Data Grid Material No. of Grids (mid-span grids)

(top/bottom grid)

(inactive length)

(Total)

Zircaloy-4 Inconel-718 6

7 Intermediate Flow Mixin Grid Data (only in 8 fuel assemblies)

Grid Material No. of Grids Zircaloy-4 3

ATTACHMENT 3 TO AEP:NRC:1249 PAGE 3

Donald C.

Cook Nuclear Plant Unit 2 Fuel T

e Informatio Fuel Type Core, Power Cycle 10 Length 17 x 17 VANTAGE 5 3411 MWz 427 EFPD I.

Fuel Rod Data Fuel Material Clad Material Clad Outer Material UO~

Zircaloy-4 0.360" II.

RCCA Data RCCA Absorber Material RCCA Clad Material RCCA Clad Outer Diameter Ag-In-Cd SS-304 0.381" III.

Guide Thimble GT Data GT Material GT Inner Diameter (above dashpot)

(at dashpot:)

Zircaloy-4 0.442" 0 397" IV.

Grid Data Grid Material (mid-span grids)

(top/bottom grid)

No. of grids (in-active length)

(total)

Zircaloy-4 Inconel-718 7.

8 V.

Intermediate Flow Mixin Grid Data Grid Material No. of Grids Zircaloy-4 3

U

ATTACHHENT 3 TO AEP:NRC:1249 PAGE 4 UNXT 1 CONTROL ROD PATTERN R

P N

M L

K J

H G

F E

P C

B A

180 2.

A' B 90'+

sc D

sA D

SA

'o sA Se se 270 12 13 QA sA 14 00

ATTACHMENT 3 TO AEP:NRC:1249 UNIT 2 CONTROL ROD PATTERN PAGE 5 R

P N

N L

K J

H G

F E

D C

3 180' 3

6 90'A SA B

C S

SEE D

C A

D A

D SEE 'C SA 0

D Sg SEI SA 270'4 SA Sp C

A 0

S SEI SA B

C Sp D

SA SC SA QO

~

re J

Be innin of C cle Assembl Burnu Page 6

Unit 1, Cycle 15 Assembly ID EE17 EE20 EE21 EE23 EE27 EE28 EE31 EE35 EE36 EE37 EE44 EE45 EE48 FF13 FF21 FF33 FF34 FF59 FF60 FF62 FF66 FF69 FF70 FF74 FF80 GG09 GG15 GG18 GG20 GG21 RCCA ID R28 R39 R501 R46 R509 R16 R26 R51 R52 R44 R10 R510 R07 R520 R41 R55 R503 R37 R40 R21 R504 R09 R15 R511 R17 R14 R30 R521 R38 R56B Core Location H10 H12 H04 H06 M08 F08 K10 F10 K06 H08 D08 K08 F06 G05 L07 E09 J13 C07 N09 G13 G03 N07 C09 J03 POS H14 H02 B08 M04 Cycle 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 Burnup 27821 28648 28688 27683 28878 27825 27660 27750 27800 30569 28726 27550 28092 18543 18481 18546 18494 17649 17598 17350 17447 17362 17383 17481 17465

/s

Attachment 3

to AEP:NRC:1249 Page 7

Assembly ID GG22 GG23 GG24 GG25 GG26 GG27 GG28 GG29 GG30 GG31 GG32 GG49 GGSO GG51 GG52 GG53 GG54 GG55 GG56 GG57 GG58 GG59 GG60 RCCA ID R08 R56A R505 R18 R508 R05 R506 R42 R13 R25 R35 R36 R502 R03 R32 R24 R47 R519 R02 R11 R29 R20 R01 Core Location D04 M12 D12 C11 L03 E13 E03 N05 C05 N11 L13 B06 K02 B10 F02 N03 K14 F14 N13 C13 C03 P06 P10 Cycle 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 Burnup

,I C

II

'I t

lt M

Attachment 3

to EP:NRC:1249 Current Assembl Burnu Unit 1, Cycle 15 Page 8

Assembly ID EE17 EE20 EE21 EE23 EE27 EE28 EE31 EE35 EE36 EE37 EE44 EE45 EE48 FF13 FF21 FF33 FF34 FF59 FF60 FF62 FF66 FF69 FF70 FF74 FF80 GG09 GG15 GG18 GG20 GG21 RCCA ID R28 R39 R501 R46 R509 R16 R26 R51 R52 R44 R10 R510 R07 R520 R41 R55 R503 R37 R40 R21 R504 R09 R15 R511 R17 R14 R30 R521 R38 R56B Core Location H10 H12 H04 H06 MOS F08 K10 F10 K06 H08 D08 K08 F06 G05 L07 E09 J13 C07 N09 G13 G03 N07 C09 J03 P08 H14 H02 B08 M04 Cycle 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 Burnup 31884 32704 32767 31753 32933 31881 31709 31809 31886 34343 32792 31615 32151 23215 23132 23227 23140 22571 22527 22291 22381 22333 22293 22411 22464 5271 5220 5385 5210 5796

Page 9

Assembly ID GG22 GG23 GG24 GG25 GG26 GG27 GG28 GG29 GG30 GG31 GG32 GG49 GG50 GG51 GG52 GG53 GG54 GG55 GG56 GG57 GG58 GG59 GG60 RCCA ID ROS R56A R505 R18 R508 R05 R506 R42 R13 R25 R35 R36 R502 R03 R32 R24 R47 R519 R02 Rll R29 R20 R01 Core Location D04 M12 D12 Cll L03 E13 E03 N05 C05 Nll L13 B06 K02 B10 F02 N03 K14 F14 N13 C13 C03 P06 P10 Cycle 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 Burnup 5697 5690 5680 5581 5714 5611 5609 5557 5583 5600 5603 5515 5639 5522 5562 4986 5515 5605 4971 4873 4964 5447 5546

Attachment 3

to AEP:NRC:1249 Page 10 End of C cle Assemhl Burnu Unit 1, Cycle 15 Assembly ID EE17 EE20 EE21 EE23 EE27 EE28 EE31 EE35 EE36 EE37 EE44 EE45 EE48 FF13 FF21 FF33 FF34 FF59 FF60 FF62 FF66 FF69 FF70 FF74 FF80 GG09 GG15 GG18 GG20 GG21 RCCA ID R28 R39 R501 R46 R509 R16 R26 R51 R52 R44 Rlo R510 R07 R520 R41 R55 R503 R37 R40 R21 R504 R09 R15 R511 R17 R14 R30 R521 R38 R56B Core Location Hlo H12 H04 H06 M08 F08 K10 Flo K06 H08 D08 K08 F06 G05 L07 E09 J13 C07 N09 G13 G03 N07 C09 J03 P08 H14 H02 B08 M04 Cycle 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 Burnup 41642 42947 42970 41627 42935 41643 41814 41828 41786 43750 42945 41590 41808 34766 34682 34766 34765 34492 34503 34534 34506 34539 34450 34502 34570 18451 18287 18489 18421 19470

Attachment 3

to AEP:NRC:1249 Page ll Assembly XD GG22 GG23 GG24 GG25 GG26 GG27 GG28 GG29 GG30 GG31 GG32 GG49 GG50 GG51 GG52 GG53 GG54 GG55 GG56 GG57 GG58 GG59 GG60 RCCA ID R08

R56A, R505 R18 R508 R05 R506 R42 R13 R25 R35 R36 R502 R03 R32 R24 R47 R519 R02 Rll R29 R20 R01 Core Location D04 M12 D12 C11 L03 E13 E03 N05 C05 Nll L13 B06 K02 B10 F02 N03 K14 F14 N13 C13 C03 P06 P10 Cycle 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 Burnup 19351 19358 19317 19321 19482 19378 19344 19215 19341 19351 19336 19430 19487 19423 19444 16683 19390 19601 16678 16430 16674 19206 19448

k k

I

Attachment 3

to AEP:NRC:1249 Page l2 Be innin of C cle Assembl Burnu Unit 2, Cycle 10 Assembly XD W61 Xo1.

X02 X03 X06 X09 Xll X14 X15 X16 X17 X18 X20 X37 X40 X42 X48 X50 X51 X53 X57 X58 X61 X62 X63 X65 X67 X68 X71 X72 RCCA T.D R131 R116 R122 Rill R141 R146 R127 R134 R120 R123 R154 R140 R101 R144 R107 R103 R124 R128 R108 R117 R147 R01 R118 R129 R112 R125 R130 R135 R150 R133 Core Location H08 K10 F06 C05 Cll E03 F10 K06 L03 N05 E13 Nll L13 M08 H04 H12 D08 J03 N09 N07 G13 J13 C07 C09 G03 M12 D12 H06 H10 K08 Cycle 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 Burnup 32513 24584 24668 24790 24814 24831 24650 24765 24698 25001 24814 24842 24909 23254 23249 23345 23326 23248 23646 23125 23726 23698 23448 23631 23639 24683 24766 23496 22852 23407

+a]

Attachment 3

to EP:NRC:1249 Page 13 Assembly ID X73

,X75 X76 Y01 Y02 Y03 Y04 Y05 Y06 Y07 Y08 Y47 Y48 Y49 Y51 Y52 Y54 Y55 Y56 Y57 Y58 Y62 Y63 RCCA 1D R114 R126 R139 R105 R113 R106 R145 R109 R142 R138 R143 R121 R136 R153 R104 R137 R18 R110 R102 R119 R155 R115 R40 Core Location F08 M04 D04 B12 M02 D14 D02 P04 B04 P12 M14 K02 P06 K14 B10 H02 F02 B08 P10 B06 P08 F14 H14 Cycle 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 Burnup 22893 24829 24675 0

pl@

Attachment 3

to AEP:NRC:1249 Page 14 End of C cle Assembl Burnu Unit 2, Cycle 10 Assembly ID W61 X01 X02 X03 X06 X09 X11 X14 X15 X16 X17 X18 X20 X37 X40 X42 X48 X50 X51 X53 X57 X58 X61 X62 X63 X65 X67 X68 X71 X72 RCCA ID R131 R116 R122 R111 R141 R146 R127 R134 R120 R123 R154 R140 R101 R144 R107 R103 R124 R128 R108 R117 R147 R01 R118 R129 R112 R125 R130 R135 R150 R133 Core Location H08 K10 F06 C05 C11 E03 F10 K06 L03 N05 E13 N11 L13 M08 H04 H12 D08 J03 N09 N07 G13 J13 C07 C09 G03 M12 D12 H06 H10 K08 Cycle 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 Burnup 49823 42372 42389 43348 43198 43403 42390 42599 43451 43680 43460 43344 43410 43528 43380 43417 43144 43169 43718 43217 43641 43454 43274 43485 43492 44392 44502 42124 41589 42253

Attachment 3

to AEP:NRC:1249 Page 15 Assembly ID X73 X75 X76 Y01 Y02 Y03 Y04 Y05 Y06 Y07 Y08 Y47

. Y48 Y49 Y51 Y52 Y54 Y55 Y56 Y57 Y58 Y62 Y63 RCCA ID R114 R126 R139 R105 R113 R106 R145 R109 R142 R138 R143 R121 R136 R153 R104 R137 R18 R110 R102 R119 R155 R115 R40 Core Location F08 M04 D04 B12 M02 D14 D02 P04 B04 P12 M14 K02 P06 K14 B10 H02 F02 B08 P10 B06 P08 F14 H14 Cycle 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 Burnup 41550 44743 44511 16172 15415 15617 15514 15516 15517 15360 15416 22069 21850 21896 22260 22240 21688 22400 21972 22111 22218 22059 21962

ATTACHMENT 4 TO AEP:NRC:1249 NRC BULLETIN 96-01

RESPONSE

NO.

3

ATTACHMENT 4 TO AEP:NRC:1249 PAGE 1

~Res esse 3

This attachment contains results of recent rod drop tests performed at Cook Nuclear Plant.

(1)

Unit 1, Beginning of Cycle 15 (2)

Unit 2, Beginning of Cycle 10 (3)

Unit 2, End of Cycle 10 It should be noted that a

new methodology for rod drop testing (multiple rod drop technique) was employed for the beginning of Unit 1, Cycle 15 and the end-of Unit 2, Cycle 10 tests.

Since the trip breaker serves as the initiation signal in the new system, the rod drop time is slightly increased (0.1 sec.

- 0.15 sec).

f To assure the rods inserted completely, the traces obtained from the Unit 2 end of cycle 10 rod drop tests were studied.

All traces exhibited similar characteristics to the beginning of cycle traces including the "bounces".

This means that all RCCAs entered the dashpot region without delay.

If additional tests are performed, the data from these tests will be transmitted as well.

1 Ei

(

1 I

Page 2

Summa of Rod Dro Times Unit 1 Cycle 15 Beginning of Cycle Bank Group SBA-1 SBA-1 SBA-1 SBA-1 SBA-2 SBA-2 SBA-2 SBA-2 SBB-1 SBB-1 SBB-1 SBB-1 SBB-2 SBB-2 SBB-2 SBB-2 SBC-1 SBC-1 SBC-1 SBC-1 SBD-1 SBD-1 SBD-1 SBD-1 Rod Location D4 D12 M12 M4 G5 E9 L7 G3 C9 J13 N7 C7 G13 N9 J3 H2 B8 H14 P8 F6 F10 Klo K6 Time to Dashpot (Tl) 1.354 1.349 1.366 1.377 1.449

1. 413 1.412 1.418 1.389 1.450 1.381

1. 413 1.410

1. 415 1.410 1.359 1.377 1 ~ 371 1.369 1.428 1.410 1.392 1.428 1.396 Total Drop Time (T2) 2.079 1.998 1.960 1.951 2.105

2. 163 2.008 2.088 2.093

2. 049 2.046 2.098 2.180 2.034

2. 179 2.056

2. 075 2.043 1.987

2. 169

2. 184

2. 045

2. 092

2. 133 Bank-Group CBA-1 CBA-1 CBA-1 CBA-1 CBA-2 CBA-2 CBA-2 CBA-2 CBB-1 CBB-1 CBB-2 CBB-2 CBC-1 CBC-1 CBC-1 CBC-1 CBC-2 CBC-2 CBC-2 CBC-2 CBD-2 CBD-1 CBD-1 CBD-1 CBD-1 CBD-2 CBD-2 CBD-2 CBD-2 Rod Location E3 Cll L13 N5 C5 E13 Nll L3 D8 M8 H4 H12 C3 C13 N13 N3 H6 F8 Hlo K8 H8 Blo K14 p6 B6 F14 P10 K2 Time to Dashpot (Tl) 1.358 1.379 1.364 1.450 1.389 1.365 1.403 1.391

1. 426 1.434 1.381 1.426 1.351

1. 371 1.366 1.369 1.392 1.407 1.403 1.434 1.481 1.385 1.424 1.390 1.391 1.463 1.498 1.458 1.462 Total Drop Time (T2) 2 014

2. 031

2. 120 2 ~ 197 2.008 2.100 2.046 2.044

2. 126 2.078 2.031

2. 098 1.978

2. 017 2 '73 2.035 2.082 2.154 2.184 2.083 2.280 1.976 2.054 1.985

2. 145

2. 072 2.151

2. 130 2.092

gib Attachment 4

to AEP:NRC:1249 Summa of Rod Dro Times Unit 2 Cycle 10 Beginning of Cycle Page 3

Bank Rod Group Location Time to Dashpot (Tl)

,Total Drop Time (T2)

Bank-Group Rod Location Time to Dashpot (Tl)

Total Drop Time (T2)

CBA-1 CBA-1 CBA-2 CBA-2 CBB-1 CBB-1 CBB-1 CBB-1 CBB-2 H6 Hlo F8 K8 F2 Blo K14 P6 B6 1.36 1.37 1.36 1.36 1.38 1.42 1.39 1.40 1.39 1.79

1. 83 1.80 1.95 1.93

1. 88 1.89 1.92

1. 88 CBD-1 CBD-2 CBD-2 CBD-2 CBD-2.

SBA-1 SBA-1 SBA-1 SBA-1 M4 H4 D8 H12 M8 D2 B12 M14 P4 1.38 1.36 1.35 1.38 1.50 1.41

l. 36 1.40 1.38

1. 81 1.75 1.78 1.82 1.96

1. 90

l. 85 1.96 1.86 CBB-2 F14 CBB-2 Plo F

CBB-2 '2 1.39 1.38 1.40

1. 82

1. 86 1.89 SBA-2 SBA-2 SBA-2 B4 D14 P12 1.37 1.43 1.37 1.90 1.94 1.85 CBC-1 CBC-1 CBC-1 H2 B8 H14 1.36 1.39 1.53 1.84

1. 87

2. 19 SBA-2 SBB-1 SBB-1 M2 G3 C9 1.42 1.38 1 ~ 37 2.00 1.96 1;78 CBC-1 P8 1.37 1.86 SBB-1 J13 1.36 1.83 CBC-2 CBC-2 CBC-2 CBC-2 CBD-2 CBD-1 CBD-1 CBD-1 F6 Flo Klo K6 H8 D4 D12 M12 1.37 1.40 1.37 1.37 1.39 1.39 1.37 1.35 1.84 1.83 1.79 1.79

1. 80 1.86 1.86 1.79 SBB-1 SBB-2 SBB-2 SBB-2 SBB-2 SBC-1 SBC-1 SBC-1 SBC-1.

SBD-1 SBD-1 SBD-1 SBD-1 N7 C7 G13 N9 J3 E3 Cll L13 N5 C5 E13 Nll L3 1.37 1.38 1.37 1.38 1.40 1.39 1.41 1.39

1. 41 1.37 1.41 1.40 1.40 1.93 1.77 1 ~ 77 1.77

1. 82 1.83 1.89 1.83 1.85 1.78 1.82 1.89 1.84

I' 4

v>

Attachment 4

to AEP:NRC:1249 Summa of Rod Dro Times Unit 2 Cycle 10 End of Cycle Page 4

Bank Group CBA-1 CBA-1 CBA-2 CBA-2 CBB-1 CBB-1 CBB-1 CBB-1 CBB-2 CBB-2 CBB-2 CBB-2 CBC-1 CBC-1 CBC-1 CBC-1 CBC-2 CBC-2 CBC-2 CBC-2 CBD-2 CBD-1 CBD-1 CBD-1 Rod Location H6 H10 F8 K8 F2 B10 K14 P6 B6 F14 P10 K2 B8 H14 P8 F6 Flo K10 K6 H8 D4 D12 M12 Time to Dashpot (Tl) 1.416 1.456 1.468

1. 462 1.473 1.516 1.452 1.450

1. 503 1.449 1.434 1.450 1.426 1.473 1.589 1.412 1.427 1.458 1.436 1.448 1.434 1.440 1.433 1.395 Total Drop Time (T2) 1.881 1.957 1.950

2. 107 2.030 2.006 1.942 1.988

2. 039 1.892 1 ~ 919 1 937 1 911 1.970 2 '59 1 ~ 904 1.966 1.988 1.921 1.885 1.863 1.982 1 ~ 959 1.830 Bank-Group CBD-1 CBD-2 CBD-2 CBD-2 CBD-2 SBA-1 SBA-1 SBA-1 SBA-1 SBA-2 SBA-2 SBA-2 SBA-2 SBB-1 SBB-1 SBB-1 SBB-1 SBB-2 SBB-2 SBB-2 SBB-2 SBC-1 SBC-1 SBC-1 SBC-1 SBD-1 SBD-1 Rod Location M4 H4 D8 H12 M8 D2 B12 M14 P4 B4 D14 P12 M2 G3 C9 J13 N7 C7 G13 J3 E3 Cll L13 N5 C5 E13 Time to Dashpot (Tl) 1.422 1 406 1.434

1. 436

1. 534 1.'528

1. 478 1.443

1. 444

1. 550

l. 589 1.503

1. 539 1.445 1.453 1.458

l. 419

l. 513

1. 541

1. 507 1.487

1. 457

1. 478

1. 477

1. 451

l. 463

l. 459 Total Drop Time (T2) 1.857 1.812 1.906 1.914 2.032 2.040 1.970 1.994 1.922 2.069 2.109

l. 996 2.114 2.076 1.901 1.946

2. 004

1. 915 1.951 1.919 1.908 1.887

2. 048

1. 915

1. 911 1.893

1. 886 SBD-1 L3 SBD-1 Nll

1. 473 1.455 1.983 1.882

e l

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