ML17228A295

Cycle 12 Startup Physics Testing Rept.

ML17228A295
Person / Time
Site:	Saint Lucie
Issue date:	09/01/1993
From:	Jimenez M, Mead W, Wachtel P FLORIDA POWER & LIGHT CO.
To:
Shared Package
ML17228A294	List: ML17228A293 ML17228A295
References
NUDOCS 9309160163
Download: ML17228A295 (19)

Text

9309160163 930910 (PRES4WAN)

PDR ADOCK 05000335 P PDR

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St. Lucie Unit 1, Cycle 12

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>et>ev M2M~Patricia ~ChdM Wachtel Date~~g~~

Reactor Engineering, St. Lucie Plant Reviewed M~ J. 7i~

Walter D.

Date Myoid, jr Reactor Engineering, St. Lucie Plant Reviewed ~PdS~ D,, zg~y'~e Modesto Jimenez Reactor Support Supervisor, Nuclear Fuel Date

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Approved Erwin J. Wunderlich Reactor Engineering Supervisor St. Lucie Plant Page 2 of16

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St. Lucie Unit 1, Cycle 12

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Table of Contents Section ~Pa e Title I 4 Introduction II 4 Cycle 12 Fuel Design III 5 Approach to Criticality IV 5 Zero Power Physics Testing V 7 Power Ascension Program VI 7 Summary VII 8 References List of Fi ures Fi ure No. Titles 9 Cycle 12 Core Loading Pattern 10 Inverse Count Ratio Plot- Channel B 10 Inverse Count Ratio Plot- Channel D 11 RCS Boron Dilution Plot 12 Power Distribution- 25% Power 13 Power Distribution- 50% Power 14 Power Distribution- 100% Power List of Tables Table No. Title 15 Cyde 12 Reload Sub-Batch ID 15 Approach to Criticality 16 Comparison of SPCND Calculations with Measured Values Page 3 of-16

~ St. Lucie Unit 1, Cycle 12

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I. Introduction The purpose of this report is to provide a description of the fuel design and.

core load, and to summarize the startup physics testing performed at St. Lucie Unit 1 following the Cycle 12 refueling. Startup physics testing verifies key core parameters are as predicted. The major parts of this tesbng program are:

1) Initial Criticality following reload,

2) Zero Power Physics Testing and,

3) Power Ascension Testing.

II. C cie12 Fuel Desi The Cycle 12 core consists entirely of fuel manufactured by Siemens Power Corporation Nuclear Division (SPCND). The 217 assemblies in the Cycle 12 core are comprised of fuel from three batches. Of these, 84 are fresh batch R assemblies consisting of natural uranium axial blanket assemblies, 84 are once burnt batch P assemblies consisting of 76 natural uranium axial blanket assemblies and 8 Vessel Fluence Reduction Assemblies (VFRAs), and 49 are twice burnt batch M assemblies.

A further breakdown of the distinct sub-batches is contained in Table 1.

This is the sixth cycle of operation utilizing gadolinia, in the form of Gd>O3, as a burnable absorber, coupled with the use of natural uranium blankets at the top and bottom of each fuel assembly. "The batch R fuel is the fifth cycle of fuel provided by SPCND that uses long lower end-caps as a means of providing protection against debris fretting in the Lower End-Fitting region.

The Cycle 12 core map is represented in Figure 1. The assembly serial numbers and Control Element Assembly (CEA) serial numbers are given for each core location. As in Cycle 11, the Cycle 12 reload employs a low-leakage design that relies on batch M fuel around the periphery, augmented with VFRAs in the core flats to further reduce the fluence on the reactor vessel welds for life extension purposes. Each VFRA is constructed to the design of a standard fuel assembly with the exception of the fuel pellets loaded in each fuel rod. The VFRA design utilizes depleted uranium instead of the standard reload enrichments. In addition, each of the outer four guide tube finger holes is loaded with a full-length hafnium insert to further suppress the flux at the vessel boundary.

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St. Lucie Unit 1, Cycle 12

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Following the fuel shuffle and prior to the approach to criticality, CEA drop time testing was performed. The objective of this test was to measure the time of insertion from the fully-withdrawn position (UEL) to the 90% inserted position under hot, full-flow conditions. The average CEA drop time was found to be 2.30 seconds with maximum and minimum times of 2.50 seconds and 2.14 seconds, respectively. All drop times were within the requirements of Technical Specifications 3.1.3.4 (i.e. less than or equal to 3.1 seconds).

III. A roach to Criticali The approach to criticality involved diluting from a non-critical boron concentration of 1633 ppm to a predicted critical boron concentration of 1408 ppm.

The actual critical concentration was observed to be 1377 ppm. Inverse countrate ratio (ICRR) plots were maintained during the dilution process using wide range channels B and D. Refer to Figures 2 and 3 for ICRR information, Table 2 summarizes the dilution rates and times, as well as the beginning and ending boron concentrations.

Initial criticality for St. Lucie Unit 1, Cycle 12 was achieved on May 29, 1993 at 0421 with CEA group 7 at 60 inches withdrawn and all other CEA's at the all rods out (ARO) position, IV. Zero Power Ph sics Testin The purpose of the Zero Power Physics Testing program is to verify that the core operating characteristics are consistent with the design predictions and to provide assurance that the core can be operated as designed. The major tests performed for the startup of Cycle 12 were the following:

1) Reactivity Computer Checkout

2) CEA Symmetry Test

3) All Rods Out Critical Boron Concentration

4) Isothermal Temperature Coefficient Measurement

5) CEA Group Rod Worth Measurements Page 5 of 16

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St. Lucie Unit 1, Cycle 12

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The tests above were performed in accordance with approved procedures .

Zero Power Physics Testing started on May 29, 1993, following initial criticality. Following the Reactivity Computer Checkout, the CEA Symmetry Test commenced. The initial test showed indications of a possible unlatched CEA and the Unit was returned to cold shutdown conditions, the reactor was disassembled, and the CEA was relatched. Criticality was achieved, again, on June 11, 1993, and Zero Power Physics Testing was reinitiated on June 12, 1993.

Proper operation of the Reactivity Computer was verified for a second time through the performance of two tests. In the first, reactor power was elevated sufficiently high to ensure maximum sensitivity of the reactivity measuring system and at the same time preserve adequate margin to the point of adding heat. The second test ascertained response to a known value of positive or negative reactivity by measuring the values of positive or negative reactor periods that result. The results of the Reactivity Computer checkout were compared to the appropriate predictions supplied by the fuel vendor. Satisfactory agreement was obtained.

Verification of proper CEA latching was confirmed through the use of the CEA Symmetry Test utilizing the Unit 1 Shutdown Groups A and B which contain

=dual CEA's. The prescribed acceptance criteria was that the reactivity measured for each dual CEA shall be within + 15.0 pcm of the average reactivity measured for the entire group. There were no unlatched CEA's for either Shutdown Group.

The All Rod's Out Critical Boron concentration was performed. The measured value was 1418.7 ppm which compared favorably with the design value of 1456 ppm, This was within the acceptance limits of k 100 ppm.

The measurement of the Isothermal Temperature Coefficient was performed and the resulting Moderator Temperature Coefficient (MTC) was obtained, The MTC was determined to be +1.54 pcm/'F which fell well within the acceptance criteria of 2 2.0 pcm/'F of the design MTC of +1.38 pcm/'F (corrected). This agreed favorably with the Unit 1 Technical Specification 3.1.1.4 which states that the MTC shall be less positive than 7.0 pcm/'F.

The final section of interest for low power physics testing is in the measurement of CEA Group Rod Worths. Rod worth measurements were performed using the Rod Swap methodology. This method involves exchanging the reference group, measured by the boration dilution technique, with each of the remaining test groups. A comparison of the measured and design CEA reactivity Page 6 of 16

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St. Lucie Unit 1, Cycle 12 0

worths is provided in Table 3. The following acceptance criteria apply to the measurements made:

1) The measured value of each test group is within %15% or 2100 pcm of the design CEA worths, whichever is greater.

2) The measured worth of the Reference Group, and the total worth for all the CEA groups measured is within 210% of the total design .

worth.

All acceptance criteria were met in that the Reference Group measured worth was within 210% of design worth and each test group was within +15% or 2100 pcm of design worth.

V. Power Ascension Pro ram During Power Ascension, the fixed incore detector system is utilized to verify that the fuel is loaded properly and there are no abnormalities occurring in the various core parameters (core peaking factors, LHR, and Tilt) for power plateaus at 25%, 50%, and >98% rated thermal power. Calorimetric, Nuclear, and hT power calibrations were performed at each of the plateaus prior to advancing reactor power to the next higher power level. A summary of the results of the flux maps at each power level is provided in Figures 5, 6, and 7.

1 Within seven days of attaining 100% power, the Hot Full Power (HFP) MTC test was performed by maintaining power constant and varying temperature. The center CEA, 7-1, was inserted to permit compensation of the resulting reactivity changes. The HFP MTC was measured to be -5.7772'pcm/'F which was within +2.0 pcm/'F of the design value of -4.2810 pcm/'F. This test also verified compliance with Technical Specification 3.1.1.4 which requires the measured MTC be less negative than -28.0 pcm/'F and less positive than 2.0 pcm/'F while thermal power is greater than 70%.

VL ~Summar A second rod drop test was performed, prior to reaching criticality on June 11.

The results of that test were consistent with the previous test conducted in May.

The average CEA drop time'was 2.36 seconds and the maximum and minimum times were 2.54 seconds and 2.22 seconds, respectively. Compliance with the applicable Technical Specifications was satisfactory for all tests.

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St. Lucie Unit 1, Cycle 12 VII. References

1) "St. Lucie Unit 1, Cycle 12 Startup and Operations Report," EMF-93-076(P), .

dated April, 1993.

2) "Initial Cr'iticality," Pre-Operational Test Procedure Number 1-3200088, Revision 3.

3) "Reload Startup Physics Testing," Pre-Operational Test Procedure Number 3200091, Revision 1.

4) "Reactor Engineering Porkier Ascension Program," Pre-Operational Test Procedure Number 3200092, Revision 3.

5) St. Lucie Unit 1 Technical Specifications.

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St. Lucie Unit 1, Cycle 12

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FIGURE 1 CYCLE 12 CORE LOADINGPATTERN P M K H Y X W V T S J G F E D C B A I

FROB M21 M18 FR 04 a b a b 21 d c d c M13 R01 POS RO5 R03 P07 R07 M12 124 125 20 MBO R17 P16 R49 R29 M03 A51 P10 R19 126 127 123 128 19 R25 R78 P75 R59 R76 M57 122 120 119 18 201 Mlo R21 P29 R33 P42 R65 R37 M33 R67 P39 R35 R24 M16 129 118 117 130 17 RO9 P12 R73 ':: P38,.;-. M92 P66 R41 M90 R83 P13 R12 116 81 82 115

.'c k>+4 R53 P72 P46 P70 R69 R56 114 132 113 83 112 15 131 FA01 a R13 Mol R64 R45 P17 R84 R81 P24 R48 M32 R61 R16 'a'~..",.b-.:~c 14 d c 13 133 111 110 109 108 134  ::.M23.'.

M19 R39 12 R32 P74 R40 P48 M87 P47 M27 P73 R31 301 107 135 106 303 11 10 R15 M07 R62 M31 R47 P23 i RBO,", P49 R82 P18 R46 M35 R63 R14 136 105 103 102 137 FA02 9,

FR05 8 a b a b R55 P'l9 P45 P71 P61 R71 ::PBO,'54 d c d c 101 99 98 84 R11 P14 R75 M89 P64 R44 M 26 R42 M91 R74 Pll Rlo 96 95 85 94 M15 R23 P35 R36 R60 R38 M 29 R58 P41 R34 R22 M09, 138 93 92 139 M58 R28 P31 R77 RBB P76 R66 R79 R26 203 91 90 89 88 69 M55 R20 P09 R52 M04 R30 M06 R50 P15 R18 140 87 304 F02 141 Ml1 R06 POB R04 ROB PO6 R02 M14 142 143 FR&, M17 M22 FA07

'a'.:'~': b a b d:I"c' c Page S of16

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St. Lucie Unit 1, Cycle 12

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HGURE 2 WIDERANGE CHANNELB BORON DILUTION 1.0 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6

$D 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 GALLONS DILUTED FIGURE 3 WIDERANGE CHANNELD BORON DILUTION 1.0 1.0 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6

~0.5 0.5 O

0.4 0.4 0.3 0.3 0.2 0.1 GALLONS DILUTED Page 10 of 16

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St. Lucie Unit 1, Cycle 12

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FIGURE 4 RCS BORON DILUTION BORON CONCENTRATION VS. GALLONS DILUTED 165 165 162 62

~159 59 CI p 156 56 0

p 53 1153

~150 50 UO147 47 gc144 141 41 138 38 135 135 PZ Eel GALLONS DILUTED Page 11 of 16

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FIGURE 5 POWER DISTRIBUTION COMPARISON WITH DESIGN AT 25% POWER MEASURE: (CECOR/~INPA UNIT 1 SNAPSHOT ID ¹ 0/

POWER LEVEL EXPOSURE EFPH CEA POSITION BORON CONC.

22.25 1 'PM DESIGN: 0.7260 0.7480 DATA SOURCE: EMF-93-076(P) -0.0220 POWER LEVEL EXPOSURE EFPH 1.1210 0.9830 CEA POSITION 2 N 1.1440 1.0150 BORON CONC 60 PPM -0.0230 -0.0320 1.0720 1.1340 1.0200 1.0890 1.1580 1.0530

-0.0170 -0.0240 -0.0330 3 0.8260 1.0300 1.1610 0.8090 0.8390 1.0410 1.1790 0.8440

-0.0130 2 -0.0110 -0.0180 -0.0350 4 1.3080 1.0780 1.2030 0.8090 1.1120 1.3150 1.0880 1.2040 0.8160 1.1310

-0.0070 2 -0.0100 2 -0.0010 2 -0.0070 -0.0190 1.1470 1.1320 1.2330 1.1420 1.2300 1.1030 1.1580 1.1400 1.2310 1.1280 1.2160 1.0940

-0.0110 3 -0.0080 3 0.0020 0.0140 21 0.0140 0.0090 6 0.4000 1.1830 1.2280 1.3070 0.9980 1.2900 0.4070 1.1980 1.2210 1.2870 0.9750 1.2500

~KEY

-0.0070 4.0150 0.0070 2 0.0200 2 0.0230 0.0400 7 MEASURED 0.4290 .1.1020 1.0010 1.3040 1.0700 DESIGN 0.4680 1.1060 0.9830 1.2500 1.0060 DELTA

-0.0390 3 -0.0040 2 0.0180 0.0540 1 0.0640 8 0.1000 0.3490 RMS DEVIATION ~gg~o 0.0970 0.3350 0.0030 1 0.0140 g Page 12 of 16

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St. Lucie Unit 1, Cycle 12

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FIGURE 6 POWER DISTRIBUTION'OMPARISON WITH DESIGN AT 50% POWER UNIT 1 MEASURE: (CECCRI~NPAX tlst I ttlttttt 0.7570 0.7770

-0.0200 1 DESIGN:

1.1390 1.0120 DATA SOURCE: 1.1710 1.0440 POWER LEVEL -0.0320 1 -0.0320 EXPOSURE CEA POSITION 1.0870 1.1500 1.0400 BORON CONC PPM 1.1110 1.1850 1.0800

-0.0240 4.0350 1q -0.0400 3 0.8470 1.0460 1.1710 0.8160 0.8550 1.0640 1.2070 0.8680

-0.0080 2 -0.0180 4.0360 1 -0.0520 1.3080 1.1000 1.2190 0.8300 1.138p 1.3030 1.0950 1.2180 0.8360 1.1480 0.0050 2 0.0050 2 0.0010 -O.OO6O 1 -O.O1OO 6 1.1350 1.1420 1 257p 1 154p 1.2470 1.1330 1.1350 1.1260 1 224p 1 13pp 1.2230 1.1010 0.0000 3 0.0160 3 0.0330 2 0.0240 2q 0.0240 0.0320 6 0.3810 1.2080 1.27gp 1.324p 1.0040 1.2820 0 4000 1 1730 1.2030 1.2740 0.9790 1.2450

~KEY

-0.0190 3 0.0350 3] 0.0760 2 0.0500 0.0250 0.0370 MEASURED 0.4790 1.1380 1.pp4p 1.2760 1.0290 DESIGN 0 4620 1.0820 p.g67p 1.2430 1.0010 DELTA ID 0.0170 3 0.0560 2 0 0370 2 0.0330 0.0280 8 0.1010 0.3470 0.0990 0.3410 RMS DEVIATION~ ~gg1 0.0020 0.0060 9 Page 13 of 16

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St. Lucie unit 1, Cycle 12

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FIGURE 7 POWER DISTRIBUTION COMPARISON WITH DESIGN AT 100% POWER MEASURE: (CECOR/INPAX)

UNIT 1 SNAPSHOT ID ¹ POWER LEVEL 880 EXPOSURE CEA POSITION BORON CONC. 7 PPM DESIGN: 0.8290 0.8520 DATA SOURCE: MF- 0.0040 POWER LEVEL EXPOSURE EFPH 1.1910 1.0760 CEA POSITION 1.2240 1.1050 BORON CONC -0.0330 "-0.0290 1.1290 1.2010 1.0960 1.1540 1.2310 1.1310

-0.0250 1 -0.0300 11 -0.0350 3 0.8770 1.0760 1.2080 0.8640 0.8850 1 0990 1.2450 0.9140

-0.0080 2 -0.0230 1 -0 0370 -0.0500 1.2860 1.0930 1.2060 0 8480 1.1480 1.2830 1.1020 1.2300 0.8680 1.1790 0.0030 2 -0.0090 2 -0.0240 2 -0.0200 -0.0310 5 1.1080 1 09 0 1.1970 1.0970 1.2080 1.1040 1.1030 1.1020 1 2p3p 1.1280 1 228p 1.1180 0.0050 3 -0.0070 3 -0.0060 2 -0.0310 2q 4.0200 1 -0.0140 6 0.3850 1.1200 1.1860 1.2460 0.9780 1.2440 0.3850 1 1210 1.1620 1.2400 0.9810 1.2500 0.0000 0240 ~KEY 3 -0.0010 3$ 0 2 0.0060 2 4.0030 1 .0060 MEASURED 0.4230 1.0400 p.954p 1.2150 0.9550 0.4440 1.0270 1.2090 DESIGN, 0.9260 0.9940 DELTA

-0.0210 3 0.0130 2 0.0280 0.0060 1 -0.0390 8 RMS DEVIATION= ~~ 0.1010 0.1010 0.0000 1 0 3310 0 3470

-0.0160 g Page 14 of 16

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St. Lucie Unit 1, Cycle 12

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TABLE 1 CYCLE 12 RELOAD SUB-BATCH ID Sub-Batch ¹ of Assemb Enrich.

Ml 16 4.00 M2 12 3.97 M3 8 3.90 M4 9 3.89 M5 4 3.87 Pl 16 3.75 P2 12 3.73 P3 40 3.65 P4 4 3.64 P5 4 3.62 P6 8 0.30 Rl 16 3.90 R2 12 3.88 R3 20 3.81 R4 24 3.79 RS 12 3.76 TABLE 2 APPROACH TO CRITICALITY Dilution Rate Init. Boron Conc. Final Boron Conc. Dilution Time(min) 88 gpm 1633 ppm 1444 ppm 151 1444 ppm 1377 ppm 78 Page 15 of 16

TABLE 3 COMPARISONS OF SPCND CALCULATIONS WITH MEASURED VALUES CEA Group Worth Summary CEAGrou Measured Desi n  % Diff.

B/5 509 570 11.98 %

7 654 591 - 9.63 %

2 699 674 - 3.58 %

1 759 689 - 9.22%

4 824 714 -13.35 %

6/3 929 825 -11.19 %

A 1099 '1059.2 -3.62 %

Total 5473 5122.2 -6.41%

Note: All worths in pcm

'%iff= (D/M-1)100 HZP Critical Boron Condition Measured Design(Adj) . Difference (M-D)

ARO 1418.7 ppm 1456 ppm -37.3 ppm Moderator Temperature Coefficient Condition Measured Design(Adj) Difference(M-D)

ARO +1.56 pcm/'F +1.38 pcm/'F +0.18 pcm/'F Page 16 of 16