ML20117G766

Provides Info on Plant Action Taken During Current Refueling Outage Re Recent Control Rod Insertion Problems

ML20117G766
Person / Time
Site:	Catawba
Issue date:	08/29/1996
From:	Mccollum W DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
IEB-96-001, IEB-96-1, TAC-M95018, NUDOCS 9609050318
Download: ML20117G766 (8)

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. l1 I Dukennwr Company Wtu. intr. AhDtwn JR Catawba Nudear Generation Department Yuce hesident

• 4800ConcordRoad (8W)S3125m Oflice York, SC29745 (8M)s31426nu

~DUKEPOWER August 29,1996 U.S. Nuclear Regulatory Commission ATTENTION: DocumentControlDesk Washington, DC 20555-0001 1

SUBJECT:

Duke Power Company Catawba Nuclear Station - Unit 1 Docket No. 50 413 NRC Bulletin 96 Outage Test Data (TAC M95018)

NRC Bulletin %-01, dated March 8,1996, requested holders of operating licenses for -  :

l Westinghouse designed plants to take actions and supply information to the NRC regarding i

. recent control rod insenion problems. The initial Duke Power response to this bulletin was l l

provided by letter dated April 4,1996 and supplemented with additional information by l l

letters dated April _30,1996 and June 7,1996. This letter provides information on Catawba l Unit I actions taken during the current refueling outage (IEOC9). j

( Restated below am peninent sections of the NRC Bulletin %-01 requiring actions during L the current Catawba Unit I refueling outage.' ,

p  ;

Requested Action (3):

f (3) Measure and evaluate at each outage of sufficient duration during calendar year L 1996 (end of cycle, maintenance, etc.), the control rod drop times and rod recoil  !

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

l a. Rods failing to meet the rod drop time in technical specifications shall be deemed inoperable.

j. b. Rods failing to bottom or exhibiting high drag forces shall require prompt corrective action in accordance with Appendix B to Part 50 of Title 10 of the Code of Federal Regulations (10 CFR Part 50).

3 Required Response Item (3):

1 9609050318 960829 PDR ADOCK 05000413 G PDR i e -ymo m-

U.S. Nuclear Regulatory Commission August 29,1996 Page 2 l

(3) Within 30 days after completing Requested Action (3) for each outage, submit a report that documents and summarizes the data obtained. This is also applicable -

to Requested Action (4) when any abnormal rod behavior is observed. j

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l Catawba Response to Item (3):

Included as Attachments I and 2 to this letter is a summary report of the Catawba Unit I  !

data for Requested Action (3) obtained during testing performed in conjunction with the i

Unit 1 End-of-Cycle 9 refueling outage. This testing was completed on July 31,1996. l I

Catawba Nuclear Station has no further refueling outages planned for the remainder of 1996. However,if forced outages of sufficient duration occur in 1996, data requested in 96-01 will be collected. Duke Power continues to have 100% successful rod insertions in  !

Mark BW fuel and continues to have substantial margin to the required Technical j Specification insertion times. Please direct any questions on this matter to Allen Smith at  !

, (803) 831-3952.

i I declare, under penalty of perjury, that the statements set forth herein are true and correct ;

to the best of my knowledge.  !

Very truly yours, I

.~ y '

i W. R. McCollum Jr. 1 i

i Attachments xc: S.D. Ebneter, Regional Administrator, Region II '

( R.J. Freudenberger, Senior Resident Inspector l

P.S. Tam, Senior Project Manager, ONRR

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Catawba Nuclear Station NRC Bulletin 96-01 l Attachment 1 Unit 1 EOC-9 Control Rod Drop Testing Results On June 14,1996 control rod drop timing was performed in accordance with the requirements of NRC Bulletin 96-01. The following is a summary of the data analysis of the End-of-Cycle (EOC) control rod drop testing results for Catawba Nuclear Station Unit 1.

During the current Unit I refueling outage (IEOC9), rod drop timing testing was performed on the control rod drive lines and rod control cluster assemblies (RCCAs).

This included a detailed analysis of control rod drop times (see attached Table 1 for drop times) and rod recoil data.

Catawba Nuclear Station has trended control rod drop times from initial plant startup in 1985. The data have been consistent during all testing on both Unit 1 and Unit 2. The test methodology used consisted of selecting a control rod bank, withdrawing the bank to the hard rod stop (231 steps), removing power from both digital rod position indication (DRPI) system data cabinets (Data A and Data B), dropping each individual RCCA by removing its movable gripper (MG) and stationary gripper (SG) fuses, recording the voltage profile induced by the RCCA drive shaft as it dropped through the coils ofits associated DRPI detector, restoring power to both DRPI data cabinets, verifying each RCCA completely inserted, and repeating this test method until all 53 control rods had been tested.

The analysis method used consisted of a detailed review of each control rod's time based pmfile. The individual drop time for each RCCA was determined by analyzing the recorded voltage profile and are shown in Table 1. Four rods, D-14, F-08, H-06, and H-08, were noted as having slightly longer drop times than the other rods. These rods were identified by calculating two standard deviations from the average drop time and comparing the recorded voltage profiles of each rod. The profiles of eight rods were superimposed on each other and compared. The mean profile was used to compare an additional seven rods.

This process was repeated until all of the rods were analyzed. The same four control rods exhibited a slight variance in their profiles. All rod drop times were well within the technical specification required time ofs 2.2 seconds. The average control rod rod drop time was 1.583 seconds, with an average rod bottom time of 2.129 seconds.

The rod drop traces were analyzed for rod recoil (an indication that the rod is fully inserted to rod bottom). All the recorded rod drop traces exhibited rod recoil with a minimum of 2 recoils for each RCCA.

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Catawba Unit i EOC-9 Control Rod Drop Testing Results Table 1 BOC-9 3/21/95 EOC9 6/14/96 EOCvsBOC Core Time to Time in Total Burnup Time to Time in Total Burnup Time to Time in Total Loc DP DP Time MWD /MTU DP DP Time MWD /MT DP DP Time H06 1.600 0.541 2.141 26000 1.743 0.639 2.382 42710 0.143 0.098 0.241 H10 1.529 0.501 2.030 25900 1.626 0.542 2.168 42260 0.097 0.041 0.138 F08 1.640 0.631 2271 25800 1.699 0.656 2.355 42260 0.059 0.025 0.084 K08 1.562 0.542 2.104 25800 1.611 0.563 2.174 42490 0.049 0.021 0.070 H02 1.559 0.544 2.103 19100 1.538 0.568 2.106 35080 -0.021 0.024 0.003 B08 1.527 0.500_ 2.033 19500 1.547 0.483 2.030 35270 0.020 -0.023 -0.003 H14 1.529 0.565 2.094 19600 1.556 0.539 2.095 35350 0.027 -0.026 0.001 P08 1.603 0.604 2207 19400 1.566 0.564 2.130 35220 -0.037 -0.040 -0.077 F06 1.529 0.532 2.061 20100 1.632 0.559 2.191 39450 0.103 0.027 0.130 F10 1.525 0.528 2.053 20000 1.570 0.542 2.112 39080 0.045 0.014 0.059 K10 1.632 0.579 2211 19900 1.600 0.577 2.177 38880 -0.032 -0.002 -0.034 K06 1.516 0.531 2.047 19800 1.597 0.556 2.153 39360 0.081 0.025 0.106 D02 1.714 0.603 2.317 23800 1.641 0.577 2.218 32810 -0.073 -0.026 -0.099 B12 1.646 0.593 2.239 23400 1.585 0.574 2.159 32440 -0.061 -0.019 -0.080 M14 1.735 0.621 2.356 23600 1.652 0.592 2.244 32590 -0.083 -0.029 -0.112 PO4 1.639 0.604 2.243 23200 1.562 0.559 2.121 32290 -0.077 -0.045 -0.122 B04 1.589 0.520 2.109 23000 1.599 0.469 2.068 32040 0.010 -0.051 -0.041 D14 1.666 0.536 2.202 23700 1.693 0.557 2250 32840 0.027 0.021 0.048 P12 1.600 0.563 2.163 23300 1.562 0.542 2.104 32230 -0.038 -0.021 -0.059 M02 1.600 0.560 2.160 23500 1.617 0.542 2.159 32550 0.017 -0.018 -0.001 E03 1.557 0.526 2.083 17000 1.579 0.542 2.121 35220 0.022 0.016 0.038 C11 1.538 0.535 2.073 16500 1.553 0.510 2.063 34820 0.015 -0.025 -0.010 L13 1.567 0.508 2.075 16800 1.553 0.510 2.063 35050 -0.014 0.002 -0.012 N05 1.533 0.519 2.052 17100 1.541 0.542 2.083 35470 0.008 0.023 0.031 C05 1.557 0.533 2.090 17100 1.547 0.542 2.089 35410 -0.010 0.009 -0.000 1

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BOC-9 3/21/95 EOC9 6/14/96 EOCysBOC Core Time to Time in Total Burnup Time to Time in Total Burnup Time to Time in Total E13 1.568 0.534 2.102 17100 1.576 0.560 2.136 35440 0.008 0.026 0.034 N11 1.546 0.517 2.063 17000 1.535 0.525 2.060 35090 -0.011 0.008 -0.003 LO3 1.639 0.595 2234 16900 1.526 0.642 2.168 35360 -0.113 0.047 -0.066 H04 1.507 0.533 2.040 27100 1.559 0.556 2.115 44430 0.052 0.023 0.075 D08 1.546 0.524 2.070 26700 1.626 0.560 2.186 43910 0.080 0.036 0.116 <

H12 1.542 0.516 2.058 27100 1.614 0.560 2.174 44030 0.072 0.044 0.116 M08 1.542 0.515 2.057 26800 1.562 0.509 2.071 43870 0.020 -0 006 0.014 F02 1.635 0.614 2249 16100 1.579 0.592 2.171 32720 -0.056 -0.022 -0.078 B10 1.514 0.555 2.069 16500 1.544 0.524 2.068 33180 0.030 -0.031 -0.000 K14 1.576 0.514 2.090 16100 1.597 0.489 2.086 32830 0.021 -0.025 -0.004 ,

P06 1.541 0.554 2.095 16200 1.553 0.559 2.112 32910 0.012 0.005 0.017 B06 1.520 0.533 2.053 15900 1.559 0.512 2.071 32520 0.039 -0.021 0.018 F14 1.600 0.561 2.161 16100 1.629 0.574 2203 32950 0.029 0.013 0.042 P10 1.554 0.518 2.072 16200 1.567 0.510 2.077 32790 0.013 -0.008 0.005 K02 1.602 0.548 2.150 16100 1.579 0.527 2.106 33000 -0.023 -0.021 -0.044 D04 1.540 0.531 2.071 19900 1.550 0.542 2.092 37650 0.010 0.011 0.021 M12 1.552 0.534 2.086 19900 1.547 0.542 2.089 37530 -0.005 0.008 0.003 D12 1.562 0.545 2.107 20000 1.582 0.542 2.124 37830 0.020 -0.003 0.017 M04 1.540 0.490 2.030 19700 1.564 0.490 2.054 37540 0.024 -0.000 0.024 H08 1.649 0.596 2.245 30200 1.702 0.592 2294 44940 0.053 -0.004 0.049 G03 1.628 0.542 2.170 16800 1.564 0.542 2.106 36310 -0.064 -0.000 -0.064 C09 1.530 0.504 2.034 16700 1.544 0.492 2.036 36020 0.014 -0.012 0.002 J13 1.511 0.535 2.046 16600 1.518 0.521 2.039 35900 0.007 -0.014 -0.007 N07 1.530 0.504 2.034 16600 1.503 0.521 2.024 36130 -0.027 0.017 -0.010 C07 1.550 0.525 2.075 16300 1.582 0.539 2.121 35570 0.032 0.014 0.046 G13 1.580 0.516 2.096 16300 1.576 0.528 2.104 35590 -0.004 0.012 0.008 N09 1.556 0.508 2.064 16900 1.588 0.539 2.127 36210 0.032 0.031 0.063 J03 1.510 0.482 1.992 16600 1.526 0.490 2.016 36160 0.016 0.008 0.024 Average 1.573 0.543 2.116 20062 1.583 0.546 2.129 36445 0.011 0.003 0.013 2

Catawba Nuclear Station NRC Bulletin 96-01 Attachment 2 Unit 1 EOC-9 RCCA Drag Testing Results On July 31,1996 rod control cluster assembly (RCCA) drag testing was performed in accordance with the requirements of NRC Bulletin 96-01. The following is a summary of the_ data analysis of the end-of-cycle (EOC) RCCA drag testing results for Catawba Nuclear Station Unit 1.

During the current Unit I refueling outage'(1EOC9), drag tesdng was performed on the -

rod control cluster assemblies (RCCAs) in the spent fuel pool after core unload. This included a detailed analysis of RCCA drag data (see attached Table 2 for drag data).

The control rod drag test arrangement consisted of a pancake load cell attached to the Spent Fuel Pool manipulator crane auxiliary hoist. The load cell was attached to the lifting bail of the spent fuel pool RCCA grappling tool. The pancake load cell's analog output was connected to a digital indicator and strip chart recorder. The RCCA grappling tool was then attached to each RCCA. The total measured weight of the RCCA and tool was recorded using the strip chart recorder while withdrawing and inserting each RCCA.

Each RCCA was withdrawn 9 feet and then insened to rod bottom. The spent fuel pool manipulator crane auxiliary hoist was operated at a constant speed of 16 ft/ min.

The analysis method used consisted of a detailed review of each RCCA's weight profile.

The maximum drag for each RCCA while in the dashpot and guide tube thimble for withdrawal and insertion was determined by analyzing the scorded voltage profile and is shown in Table 2. The weight of the spent fuel pool RCCA grappling tool was 40 lbs. as measured submersed in the pool with no RCCA attached. The average measund weight of j an RCCA and the tool was 113 lbs. with the RCCA raised 9 ft and at rest. This weight was used as the refemnce weight. The recorded maximum drag for each RCCA was calculated by determining the total weight at specific points on the drag traces and subtracting the reference weight (RCCA plus tool). Catawba RCCA drag traces did not reveal any abnormalities of the fuel assemblies tested.

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Catawba Unit 1 EOC 9 RCCA Drag Test R:sults -

Tatde 2

• CORE FUEL ASSEM. DASHPOT GUIDE THIMBLE LOCAT. RCCA ASSEM. BURNUP INSERTION WITHDRAWAL INSERTION WITHDRAWAL DRAG DRAG DRAG DRAG HO6 R46 J29 42710 59 52 38 39 H10 R14 J66 42260 40 35 24 22 F08 R172 J52 42260 48 45 26 27 K08 R07 J02 42490 38 27 21 19 H02 R12 K32 35080 25 21 7 3 B08 R53 K61 35270 20 15 6 2 H14 R27 K17 35350 24 17 8 5 P08 R169 K13 35220 29 27 8 10 F06 RO1 K29 39450 53 39 33 31 F10 R05 K64 39080 23 22 15 12 K10 R170 K12 38880 51 30 14 14 K06 R08 K27 39360 56 37 29 24 D02 R166 J31 32810 28 25 10 10 812 R173 J16 32440 28 22 9 8 M14 R174 J26 32590 21 21 7 5 PO4 R171 J56 32290 21 20 7 4 B04 R20 J62 32040 29 17 6 3 D14 R108 J69 32840 38 23 16 15 P12 R49 J23 32230 31 22 13 10 MO2 R48 J32 32550 28 23 10 9 E03 R03 K55 35220 30 22 7 4 C11 R40 K08 34820 23 27 9 7 L13 R37 K42 35050 23 14 9 4 N05 R29 K23 35470 32 22 4 2 C05 R36 K67 35410 28 20 8 6 E13 R52 K21 35440 43 27 18 12 N11 R42 K39 35090 33 24 10 7 LO3 R167 K57 35360 37 27 10 7 H04 R45 J39 44430 38 32 18 15 D08 R22 J38 43910 36 34 19 17 H12 R107 J14 44030 37 37 19 20 M08 R19 J36 43870 30 22 12 8 F02 R165 K03 32720 33 20 8 4 Page 1 of 2

_ _ _ _ _ _ _ . _ _ . _ _ . _ . . . . _ _ _ ______..___._._ _ __. ______ _ ____ __._._ _ ___ _ ______ _ _ _ _ _ _.___________ _ _ _ _ _ __ _ _ _ d

Catawba Unit 1 EOC 9 RCCA Drag Test Results ,

Table 2 CORE FUEL ASSEM. DASHPOT GUIDE THIMBLE

_LOCAT. RCCA ASSEM. BURNUP INSERTION WITHDRAWAL INSERTION WITHDRAWAL DRAG DRAG DRAG DRAG B10 R51 K69 33180 26 19 9 7 K14 R41 K34 32830 21 21 9 4 P06 R06 K28 32910 27 17 9 6 B06 R31 K76 32520 31 21 9 8 F14 R25 K70 32950 33 27 11 11 P10 R38 K20 32790 17 19 7 4 K02 R64 K36 33000 27 18 6 4 D04 R15 K02 37650 37 20 4 5 M12 R39 K62 37530 21 20 13 7 D12 R158 K60 37830 31 27 16 14 M04 R50 K19 37540 31 22 7 5 H08 R161 J67 44940 40 35 21 19 -

G03 R168 K43 36310 21 26 9 6 C09 R26 K72 36020 17 22 8 4 J13 R16 K71 35900 21 22 10 7 N07 R109 K54 36130 28 20 9 7 C07 R23 K41 35570 31 27 19 14 G13 R47 K50 35590 29 27 15 11 N09 R43 K35 36210 33 20 10 8 J03 R18 K18 36160 33 20 8 4 Page 2 of 2

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