ML20086Q713

Startup Test Rept,Vermont Yankee Cycle 18

ML20086Q713
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	07/25/1995
From:	VERMONT YANKEE NUCLEAR POWER CORP.
To:
Shared Package
ML20086Q689	List: ML20086Q686 ML20086Q713
References
NUDOCS 9507280158
Download: ML20086Q713 (12)

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r STARTUP TEST REPORT  :

VERMONT YANKEE CYCLE.18

Introduction:

' Vermont Yankee Cycle 18 initial startup commenced on May 2,1995 l following a 45 day outage for refueling and maintenance activities. 3 The core loading for Cycle 18 consists of:

l 40 BP8DWB311-10GZ reinserts from Cycle 16 80 BP8DWB311-11GZ reinserts from Cycle 16 i 96 BP8DWB335-10GZ reinserts from Cycle 17 32 BP8DWB335-11GZ reinserts from Cycle 17 1 88 BP8DWB335-10GZ non-irradiated assemblies  !

32 BP8DWB335-11GZ non-Irradiated assemblies  !

I An as-loaded Cycle 18 core map is included as Figure 1. Details of i the Cycle 18 core loading are contained in the Yankee Atomic Electric  !

Company document YAEC-1908, " Vermont Yankee Cycle 18 Core Performance ,

Analysis Report", January 1995.

l l-The final as-loaded core loading was verified correct by Vermont Yankee personnel on April 13,1995. '

Control rod coupling verification was performed satisfactorily for  !

all 89 control rods on April 13 and 14,1995. Control rod scram testing  ;

was performed satisfactorily prior to reaching 30% power per Technical Specifications. The testing was performed for all 89 control rods on  :

April 23 and May 3,1995. l An in-sequence critical was performed satisfactorily on May 2,1995. ,

The shutdown margin was verified to be satisfactory based upon the l data collected from the in-sequence critical.

. Startup commenced May 2,1995 and steady state full power conditions were reached May 9,1995. j 1

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l 9- l Cor6 Verification:

The final core loading was verified correct on April 13,1995 in accordance with Vermont Yankee procedure OP1411. Three separate criteria.

were checked:

1. Proper bundle seating was verified.

2. Proper bundle orientation, channel fastener integrity and upper tie plate cleanliness were verified.

3. Proper core loading was verified by checking the serial number of each bundle through the use of a video camera. This verification was recorded on video tape and was later independently reviewed and reverified to agree with the licensed core loading of Figure 1.

Process ComDuter Data Checks:  :

Process computer data shuffling checks were completed on #

April 26,1995. These checks included various manual and computer checks of the new data constants. A check for consistency of the data was also performed by Yankee Atomic Electric Company (YAEC) and found to be satisfactory.  !

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.in-Seauence Critical:

The in-sequence critical test was performed on May 2,1995 as l' part of the reactor startup. Control rod sequence 18-A-2(1) was used to perform the in-sequence critical test. Criticality was achieved on the 9th rod in group 2 (18-31) at notch position 18. The moderator temperature was 136 F.

The actual critical rod pattern and the prediction agreed within j

+ /- 1% AK. Figure 11 shows the actual, predicted and the + /- 1% AK i critical rod patterns.

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e Cold Shutdown Marain Testina:

The cold shutdown margin calculation was performed using data .

collected during the in-sequence critical and information provided in  !

the YAEC " Cycle 18 Core Management Report" (YAEC-1915). The minimum ,

shutdown margin required was 0.32% AK. The actual shutdown margin was  ;

shown to be 1.41% AK. j Control Rod Scram Testina:  ;

Single rod scram testing of all 89 control rods was completed on ,

April 23 and May 3,1995. Allinsertion times were within the limits  ;

defined in the Vermont Yankee Technical Specifications. Results of the testing are presented in Table IA.

i in accordance with Technical Specifications Section 4.3.C.2, scram time information availabla for scrams occurring since the ,

transmittal of the previous startup test report is included in Table IB. i Thermal Hydraulic Limits and Power Distribution:

The core maximum fraction of limiting critical power ratio (MFLCPR),-

the core maximum fraction of limiting power density (CMFLPD), the maximum ,

average planar linear heat generation rate ratio to its limit (MAPRAT) and the ratio of CMFLPD to the fraction of rated power (FRP) were all checked daily during the startup using the process computer. All checks of core thermal limits were within the limits specified in the Technical Specifications.

l The process computer power distribution was updated twice ,

using the traversing incore probe (TIP) system during the ascent to full power. The results of these updates are presented in Table 11.  ;

The local power range monitors (LPRMs) were manually calibrated once in conjunction with the TIP system. The LPRM high and low trip alarm set points were verified correct prior to startup on April 30,1995.  :

. All LPRM operating voltages and the initial calibration currents for the two new LPRM strings were' set prior to startup. The TIPS'and the LPRMs i were both functionally tested and found to operate satisfactorily.

A total of 13 APRM gain adjustments were done as required during the startup from May 2 through May 10,1995.

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3, The process computer power distribution update performed on May -16,1995 (TIP set 1529) was used as a basis for comparison with an off line calculation performed using the Yankee Atomic Electric Company nodal code SIMULATE-3. For that power distribution, the SIMULATE-3 core average axial power distribution was compared to that calculated by the plant process computer. Comparisons are shown in Table Ill. A comparison was also performed between SIMULATE-3 and process computer peak radial power. These values show reasonable agreement and are presented in Table IV.

At approximately 25, 50, 75 and 100 percent power levels the process computer heat balance was compared with an off-line computer calculation.

The values of core thermal power from each method were found to be in excellent agreement (within 5 Megawatts thermal).

A core flow calibration was completed on May 15,1995 to ensure that the core flow calculation by the process computer is accurate over the entire operating range.

TIP Reproducibility and TIP Symmetryl TIP system reproducibility was checked in conjunction with the power distribution update performed on May 4,1995. All three TIP system traces were reproducible to within 2.3%. A TIP intermachine calibration was successfully completed on May 5,1995. A check of tip axial alignment was completed on May 31,1995 and found to be acceptable.

The total TIP uncertainty was calculated using TIP set 1529. Since the rod pattern was symmetric, the actual plant TIP readings were used in the calculation. The resulting total TIP uncertainty for this case was 1.35%. The results of the TIP uncertainty test as shown in Figure 111 are well below the 8.7% acceptance criteria.

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TABLE IA CONTROL ROD SCRAM TESTING RESULTS VERMONT YANKEE BEGINNING OF CYCLE 18 Single Rod Scrams - April 23, May 3,1995 Maximum 92.01% insertion time (seconds) = 2.973 Tech. Spec. Limit for slowest 90% insertion time (seconds) = 7.000 Mean time for % insertion 4.51 % 25.34 % 46.18% 87.84 %

Measured time (sec) 0.317 0.821 1.334 2.413 ,

Tech. Spec. limit (sec) 0.358 0.912 1.468 2.686 Slowest 2x2 arrav for % insertion 4.51% 25.34 % 46.18 % 87.84 %

Measured time (sec) 0.324 0.839 1.361 2.474 Tech. Spec. limit (sec) 0.379 0.967 1.556 2.848 i

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l TABLE IB CONTROL ROD SCRAM TESTING RESULTS ,

VERMONT YANKEE CYCLE 17 )

i Full Scram - April 10,1994 Maximum 92.01% insertion time (seconds) = 2.758 Tech. Spec. Limit for slowest 90% insertion time (seconds) = 7.000 Mean time for % insertion 4.51 % 25.34 % 46.18 % 87.84 %

Measured time (sec) 0.308 0.803 1.303 2.376 Tech. Spec. limit (sec) 0.358 0.912 1.468 2.686 Slowest 2x2 arrav for % insertion 4.51% 25.34 % 46.18 % 87.84 %

Measured time (sec) 0.324 0.836 1.354 2.461 Tech. Spec limit (sec) 0.379 0.967 1.556 2.848 i

Single Rod Scrams at Power - Sept. 2,1994 Maximum 92.01% insertion time (seconds) = 2.804 Tech. Spec. Limit for slowest 90% insertion time (seconds) = 7.000 Mean time for % insertion 4.51 % 25.34 % 46.18 % 87.84 %

Measured time (sec) 0.314 0.818 1.326 2.402 Tech. Spec. limit (sec) 0.358 0.912 1.468 2.686 Slowest 2x2 array for % insertion 4.51% 25.34 % 46.18 % 87.84 %

Measured time (sec) 0.331 0.850 1.370 2.479 ,

Tech. Spec. limit (sec) 0.379 0.967 1.556 2.848

4, TABLE 11 Vermont Yankee Power Distribution Measurements Cycle 18 Start-Up  !

Core Date Time Power (%) Flow (%) CMFLPD MFLCPR MAPRAT  :

5/4/95 22:51 68.9 55.0 0.651 0.778- 0.621 5/5/95 02:45 67.2 55.0 0.595 0.764 0.568 The Tech. Spec. limit for the three thermal limits above is '

less than or equal to 1.0.

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9 Comparison of Process Computer.and SIMULATE-3 Core Average Axial Relative Power Distributions '

Vermont Yankee Beginning of Cycle 18  ;

Process l Node SIMULATE-3 Computer 25 0.108 0.122 24 0.195 0.203 23 0.487 0.502 22 0.628 0.658 i 21 0.724 0.762 '

20 0.836 0.854 19 0.934 0.951 18 1.011 1.025 17 1.109 1.108 16 1.207 1.204 15 1.252 1.243  ;

14 1.253 1.226 13 1.272 1.240 12 1.276 1.249 .

11 1.273 1.231 10 1.261 1.220 9 1.282 1.258  !

8 1.309 1.282 ,

7 1.342 1.277 6 1.371 1.342  :

5 1.361 1.353 '

4 1.280 1.269 3 1.134 1.139 -

2 0.859 0.860 1 0.233 0.422 ,

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a3 TABLE IV Comparison of 10 Highest Relative Radial Powers ,

Vermont Yankee Beginning of Cycle 18 l Process Location Computer SIMULATE-3 l

............ .............. .................. 1 25-20 1.391 1.389 29-20 1.343 1.332 25-16 1.343 1.331 i

25-18 1.338 1.317 l

27-20 1.332 1.315 l

23-20 1.324 1.318 25-22 1.320 1.318 29-16 1.308 1.296  !

27-16 1.302 1.289  ;

29-18 1.292 1.288 l

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<. Figure I VERMONT YANKEE i Cycle 18 Core Map g YJ YJ YJ YJ YJ YJ 1151 l1991 1047 l1948 1092 l1152 q YJ YJ YJ YJ YJ YJ 1YJ l YJ334 l5350 5254 5351l5255 l5335 l2591 g YJ YJ YJ YJ g YJ YJ g YJ g YJ 5327 g5287 YJ YJ g YJ LYV g YJ 2579lLYV518 5290 5304 5286 532s 1043 1044 5307 5291 419 2580 Y' Y' Y# Y' #^ Y# Y' Y' 38 113 274 l5342 5278 001 Y'"lVJ" 033lYd* Y##8l*10Y#^lYd" 005 009 06 002 034 Y'"l5279 343l5275l116 I g YJ j YJ J gYJA YJ gYJA YJ gYJA YJ g YJ 'YJAgYJ YJAgYJ ' JAgYJ YJ g YJ 1979 $344 5286 013 1969 837 1183 041 1041 1052 042 1164 038 1040 014 5257 5347 1080 g YJ g YJ VJ YJA VJ YJ YJA YJ YJ YJ YJ YJ gYJA 050 5247 lYJA 1083 5354 YJA 17 l5318 045 l5244 YJA 49 l5242 053 lYJA 054f4243 046f 319 jYJA 018 5355 l1064 y YJ j YJ YJ YJ gYJA YJ gYJA YJ YJ kJAgYJ YJAgYJ YJA YJ YJ g YJ 5358 5322 1987057lYJA 1159 tot 2568 085 2571 l2572 068 1096 082 1180 058 l1088$323 5359 g YJ YJ YJA YJ YJ YJ YJ YJ VJ YJ YJ YJ YJAjYJ5314 877 l5258 081YJA 5234l5235 l5270 271lYJA 082 5259lYJA 5315 074 l070 YJA l5295 l1140 YJA 119 l52$4 069 lYJA 073 078 gg YJ YJ WJ gYJA YJgYJA YJ YJ YJ gYJA 1131 JAgYJ YJAgYJ YJAgYJ YJA g YJ5243 YJ YJ 2587l5338 5282 021YJ gYJA g1132094 1147 085 1155 089 1123 093 1124 090 1154 088 1148 022 5339l2588 YJ W W W W W W YJ YJ YJA YJA YJ YJ YJ 26 5310lWA 025 , WA l5282 1067l5330 97 101""l5235 WA 05 l5250109WAlWA 110 251lYJA 108 5239102flYJA283 l098026l5311 3:1 l1968 g YJ YJ YJ YJ YJ YJ YJ YJ YJ YJ g YJ YJ YJA YJ 1127g5302 1055 gYJA 1075 113g YJA1871 l5298 1143gYJA 117 2575 g2576118YJA 1144g YJ YJ j YJ 029 5299 1972 YJA 114 l1078 030 l105653031128 g YJ YJ YJ YJA YJ YJ YJ YJ YJ YJ YJ YJ YJ YJ YJA YJ YJ YJ 1129 l5304 1057 l0311151977 lYJ A 1873 145its l5300 lYJA 2577 l2578 120YJA l1144 YJA l1078 032 l1058 5301l1074its 5305l1130 20 Y# YJ YJ YJAgYJ YJAgYJ TJAgYJ YJA gYJA YJ gYJA YJ jYJA J gYJA YJ 1059l5332 5312 027jYJA 099 5284 103 5240 107 5252 111 112 5253 108 5241 104 5285 100 YJAgYJ53135333jYJ 028 1070 18 WW W W W W WA WW YJ YJA YJ YJ YJA YJ YJ YJ 2589 l5340 5264 023 r lWA149087 lWA 1157 091 lWA125 l095 1133 l1134 Y#^

98 l1126 092 l115 YJA 88 l1150 024 l5265 4 1l2590 W W^ " WA W W W 16

^ 5316 079l5260083 l52725W 071 *975*IW 1141 IW5296lW 238lW 5237 5273 IWA084 5281W IWA 078 W^lW W IWA 080 5317 072 5297 i1942 g YJ YJ YJ YJA VJ YJ VJ , YJ YJ YJ YJ YJ YJ 5360 l5324 089 l059 1141 083 lYJA 569lYJA 067 2573l2574 058YJA 064YJAl2570 YJA l1162 80 l1090 5325l5381 g YJ g YJ JAgYJ YJAgYJ 'YJAgYJ YJA gYJA YJ gYJA YJ gYJA YJ gYJA YJ g YJ 1065 5358 019 5320 047 5248 051 5244 055 054 5245 052 5249 048 5321 020 5357 1066 10 Y' YJ YJ TJ YJA Y' Y' YJ YJ YJA YJ YJ YJ 1081 l5 288 lYJA 1041 l839 itslY'^ I YJ 5349l1082 015 043 1053 1054g44 Y#^l1164040YJ^ l106g18 l5269 WW W 08 1137 l5278 lW 53445280 IWA 035 **lVJA 003 007 Y'A 011 lYJA YJA gYJA 012 003 004 YJA 036 YJ ' VJ g YJ YJ l52815345 5277l1138 00 Y# l'YV Y' Y' Y' YJ YJ VJ YJ YJ YJ YJ YJ 2581 620 5292 l5308 5288 l5328 1045 l1048 5329 l8289 421LYV l2582 5309 l5293 g YJ YJ YJ YJ YJ YJ YJ g YJ 1121 l5338 l5352 5256 l5257 5353 l5337 1122 02 YJ YJ YJ YJ YJ YJ 1153 l1093 1049 l1050 1094 l1154 01 03 05 07 09 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 g LPRM LOCArlON (COMMON LOCATION FOR ALL YlP MACHINES 43 O LPRM LOCATION (LETTER INDICATES TIP MACNINE) 3$

IRM LOCATION 31

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[ SRM LOCA710N 23 19 15 11 07 03 02 06 10 14 18 22 26 30 34 38 42

Figure II

'. t CRITICAL RCD COEfFIGURATION COMPARISON Vermont Yankee Beginning of Cycle 18 43 48 24 39 48 48 48 48 35 48 48 31 48 48 48 27 48 48 23 48 48 48 48 48 48 19 48 48 15 48 26 48 11 48 07 48 48 48 48 03

-it AK Predicted Critical Pattern s2 06 10 14 18 22 26 30 34 38 42 02 06 10 14 18 22 26 30 34 38 42 10 43 48 48 48 48 39 48 l 48 48 48 10 10 35 48 48 48 31 48 18 48 48 48 10 10 10 27 48 48 48 48 23 48 48 48 48 48 48 48 48 10 10 10 19 48 48 48 48 15 48 48 48 l

10 10 11 48 48 48 48 07 48 48 48 48 10 03 -

+1% AK Actual Critical Pattern e

Note: A blank box denotes rod position 00 r

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Figure =III J Vermont Yankee j Total TIP Uncertainty l i

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02 06 10 14 18 22 26 30. 34 38 42 e i

TIP: 1529 'l i

Date: May 16, 1995 .j

-t' CTP: 99.9%

Core Flow: 96.5% 1 Uncertainty: 1.35% j r

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