ML022190243

Cycle 9 Startup Report

ML022190243
Person / Time
Site:	Seabrook
Issue date:	07/31/2002
From:	St.Pierre G North Atlantic Energy Service Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NYN-02075
Download: ML022190243 (13)

Text

North Atlantic Energy Service Corporation P.O. Box 300 North P Atlantic Seabrook, NH 03874 (603) 474-9521 The Northeast Utilities System July 31, 2002 Docket No. 50-443 NYN-02075 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 Seabrook Station Cycle 9 Startup Report In accordance with the requirements of Technical Specification 6.8.1.1, enclosed is the Cycle 9 Startup Report for Seabrook Station.

Should you require further information regarding this matter, please contact Mr. Paul V. Gurney, Manager - Reactor Engineering, at (603) 773-7776.

Very truly yours, NORTH ATLANTIC ENERGY SERVICE CORP.

4 G.F. St. Pierre Station Director cc: H. J. Miller, NRC Region I Administrator R. D. Starkey, NRC Project Manager, Project Directorate 1-2 G.T. Dentel, NRC Senior Resident Inspector A vo!

ENCLOSURE TO NYN-02075 SEABROOK STATION UNIT NO. 1 STARTUP TEST REPORT CYCLE 9

INDEX 1.0 CHRONOLOGICAL

SUMMARY

2.0 CORE DESIGN

SUMMARY

3.0 LOW POWER PHYSICS TESTING

SUMMARY

(LPPT) 4.0 POWER ASCENSION TESTING

SUMMARY

(PAT) 5.0 TEST RESULTS TABLE 1 LPPT RESULTS TABLE 2 PAT FLUX MAP RESULTS TABLE 3 FULL POWER THERMAIJHYDRAULIC DATA i

1.0 CHRONOLOGICAL

SUMMARY

Cycle 9 Fuel Load was completed May 16, 2002. Subsequent operation/testing milestones were completed as follows:

INITIAL CRITICALITY 05/30/02 LPPT COMPLETED 05/30/02 ON LINE 05/31/05 30% PAT COMPLETED 06/01/02 50% PAT COMPLETED 06/02/02 80% PAT COMPLETED 06/03/02 94% PAT COMPLETED 06/04/02 FULL POWER 06/04/02 1 of 9

2.0 CORE DESIGN

SUMMARY

The Cycle 9 core is designed to operate for 17,940 MWD/MTU with a coastdown to 19,400 MWD/MTU. Eighty-four (84) fresh fuel assemblies were loaded into the Cycle 9 core. Seventy-two have an enrichment of 3.6 w/o and twelve have an enrichment of 4.0 w/o. In addition, the top and bottom 6 inches have an enrichment of 2.6 w/o creating an axial annular blanket. By comparison, Cycle 8 utilized 88 fresh fuel assemblies, 64 with enrichments of 3.8 w/o with a similar 2.6 w/o axial annular blanket configuration and the remaining 24 at 4.2 w/o with a similar 2.6 w/o axial annular blanket configuration.

Two mechanical designs are used in the Cycle 9 core:

" The fresh region 11 fuel is of the Robust Fuel Assembly (RFA) design, which includes slightly thicker RCC guide and thimble tubes as well as a different mid grid design. The mid-grid design is expected to mitigate grid-to-rod fretting seen in V5H assemblies.

"* The remaining reload regions 8, 9 and 10 are Vantage 5H.

" All fuel utilizes ZIRLO for fuel clad, control rod guide tubes and instrument thimbles. The top and bottom grids are Inconel-718. In addition, all fuel contains a Performance+ debris mitigation grid located at the bottom end plug of the fuel rod

"* Region 8 and 9 low-pressure drop mid-zone grids are Zircaloy-4 with Zircaloy sleeves.

"* Region 10 and 11 low-pressure drop mid-zone grids are ZIRLO with ZIRLO sleeves.

"* Region 10 and 11 fuel assemblies also have three ZIRLO intermediate flow mixers grids.

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3.0 LOW POWER PHYSICS TESTING

SUMMARY

Testing was performed in accordance with the following general sequence:

1. Initial Criticality: Criticality was achieved by withdrawing all shutdown and control banks and diluting to critical.

2. Zero Power Test Range Determination: This was determined after the point of adding heat had been demonstrated.

3. On-line Verification of the Reactivity Computer: This was determined by examining the output of the Advanced Digital Reactivity Computer (ADRC) during rod withdrawal and the determination of the point of adding heat.

4. Boron Endpoint Measurement: This was determined with all the Control and Shutdown banks withdrawn using the ADRC.

5. Isothermal Temperature Coefficient Measurement (ITC): This was determined using the ADRC during a Reactor Coolant temperature change. The Moderator Temperature Coefficient (MTC) was calculated from the ITC Data.

6. Rod Worth Measurement: Individual control bank and shutdown bank worths were measured using the Dynamic Rod Worth Measurement (DRWM) technique with the ADRC.

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4.0 POWER ASCENSION TESTING

SUMMARY

Testing was performed at specified power plateaus of 30%, 50%, 80%, 94% and 100%

Rated Thermal Power (RTP). Power changes were governed by operating procedures and fuel preconditioning guidelines.

In order to determine the core power distribution, flux mapping was performed at 30%,

50% and 100% RTP using the Fixed Incore Detector System. The resultant peaking factors were compared to Technical Specification limits to verify that the core was operating within its design limits.

Thermal-hydraulic parameters, nuclear parameters and related instrumentation were monitored throughout the Power Ascension. Data was compared to previous cycle power ascension data at each test plateau to identify calibration or system problems.

The major areas analyzed were:

1. Nuclear Instrumentation Indication: Overlap data was obtained between the Intermediate Range and Power Range channels. Secondary plant heat balance calculations were performed to verify the Nuclear Instrumentation indications.

2. RCS Delta-T Indication: All RCS AT loops were initially scaled using Cycle 8 values. Data from 30%, 50%, 80%, and 94% RTP met prescribed acceptance criteria. Data was evaluated at 100% RTP and the AT loops were re-scaled.

3. Upper Plenum Anomaly: In early 1992, Westinghouse notified North Atlantic that Seabrook Station may be susceptible to a phenomenon known as the Upper Plenum Anomaly (UPA). The UPA is primarily characterized by a periodic step change of 1VF to 20F in hot leg temperature. Cycle 9 data collected at 100% RTP identified an UPA. The data suggest the UPA is not as aggressive as it was at the start of Cycle 8, however it is still present.

4. RCS Temperatures: Data was obtained for the Narrow Range Loop temperatures.

Evaluations for Delta-T (°F), TAvG Deviation Alarm Setpoint and TAVG / TREF Indication were performed.

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4.0 POWER ASCENSION TESTING

SUMMARY

(Continued)

5. Steam and Feedwater Flows: Data was obtained for the steam and feedwater flows.

Evaluations for deviations between redundant channels on individual steam generators were performed.

6. Steam Generator Pressures: Data was obtained for the steam generator pressures.

Evaluations for deviations between redundant channels on individual steam generators were performed.

7. Turbine Impulse Pressure (TRE): The initial scaling of impulse pressure was left the same as Cycle 8. The full power value was slightly higher than the current scaling value and is within the allowed deviation criteria.

8. Incore/Excore Calibration: Scaling factors were calculated from flux map data using the single point calibration methodology. The nuclear instrumentation power range channels were re-scaled at 50% and 100% RTP.

9. RCS Flow: The RCS flow was measured at the 94% RTP plateau using elbow tap measurements to minimize the effects of observed hot leg streaming.

The power ascension test program is essentially unchanged from Cycle 8.

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5.0 RESULTS

1. Low Power Physics Testing: Acceptance criteria and review criteria were met. See Table 1 for results.

2. Flux Mapping: No problems were identified during the flux maps at 30%, 50%, and 100% RTP. See Table 2 for results.

3. Full Power Thermal/Hydraulic Evaluation: No problems were encountered with the instrumentation. Data collected at 100% RTP suggest the UPA is not as aggressive as it was at the start of Cycle 8. See Table 3 for results.

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TABLE 1 LOW POWER PHYSICS RESULTS: CYCLE 9 ITEM MEASURED PREDICTED ERROR CRITERIA BORON END POINTS:

+/- 1000 pcm HZP ALL RODS OUT 1823 ppm 1820 ppm 22 pcm +/- 500 pcm*

ALL RODS OUT ITC (pcm/F) -1.29 -2.17 0.88 +/- 2*

ALL RODS OUT MTC (pcm/F) 0.47 -0.41 N/A <+ 2.92**

CONTROL BANK ROD WORTHS:

(pcm)

• A 910.6 845.2 -65.4

• B 636.3 601.6 - 34.7 eC 917.4 847.4 -70.0 oD 603.6 562.8 -40.8

• SA 271.7 269.2 -2.5 SB 751.0 728.1 -22.9

.SC 370.3 368.6 - 1.7

• SD

• SE 381.7 369.5 - 12.2 491.2 478.7 - 12.5 8%*

TOTAL 5333.8 5071.1 - 262.7 >90%

NOTE:

• Review criteria, all others are acceptance criteria.

• • COLR limit is 2.92 BOC.

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TABLE 2 POWER ASCENSION FLUX MAP RESULTS: CYCLE 9 ITEM MAP 1 MAP 2 MAP 3 DATE OF MAP 06/01/02 06/02/02 06/04/02 POWER LEVEL (%) 29.4 48.8 99.64 CONTROL BANK D 149 198 226 POSITION (steps)

RCS BORON (ppm) 1602 1558 1307 FQ 2.0379 2.3020 1.8854 FAH 1.5175 1.4965 1.4421 INCORE TILT 1.0094 1.0089 1.0057 8 of 9

TABLE 3 FULL POWER THERMAL-HYDRAULIC DATA: CYCLE 9 ITEM VALUE REACTOR COOLANT TAVG 586.60 OF REACTOR COOLANT DELTA-T:

• LOOP 1 58.68 OF

• LOOP 2 59.09 OF

• LOOP 3 57.52 OF

• LOOP 4 58.04 OF REACTOR COOLANT FLOW: (Based on elbow tap measurements)

TOTAL 406355 GPM AUCTIONEERED HIGH TAVG 587.34 OF TREF 587.39 TI TURBINE IMPULSE PRESSURE 667.28 PSIG STEAM GENERATOR PRESSURES:

"* A 966.37 PSIG

" B 968.10 PSIG

" C 968.64 PSIG

" D 968.59 PSIG 9 of 9