ML20211F440

Cycle 6 Startup Test Rept for Seabrook Station,Unit 1

ML20211F440
Person / Time
Site:	Seabrook
Issue date:	09/26/1997
From:	NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO)
To:
Shared Package
ML20211F438	List: ML20211F433 ML20211F440
References
NUDOCS 9710010077
Download: ML20211F440 (11)

Text

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. . Docket No. 50443 .

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SEABROOK STATION -

UNIT NO,1 STARTUP TEST REPORT CYCLE 6 ,

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- INDEX

'I.0 CIIRONOLOGICAL

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 THERMAUHYDRAULIC DATA 1-

l'.0 ' CIIRONOLOGICAL

SUMMARY

4 Cycle 6 Fuel Load was completed June 12, 1997. Subsequent operation / testing milestones were completed as follows:

INITIAL CRITICALITY 06/26/97 LPPT COMPLETED 06/27/97 ON LINE 06/28/97 30% PAT COMPLETED 06/29/97 50% PAT COMPLETED 06/30/97 75% PAT COMPLETED 07/01/97 l 90% PAT COMPLETED 07/02/97 l

FULL IOWER 07/02/97 t-5

2'.0 CORE des 1GN

SUMMARY

The Cycle 6 core is designed to operate for 22,253 MWD /MTU (575 Effective Full Power Days). Eighty Four (84) fresh fuel assemblies wrn loaded into the Cycle 6 core. Eighty have an enrichment of 4.95 w/o. In addition, the top and bottom 6 inches have an j enrichment of 2.6 w/o creating an axial annular blanket. The remaining four fuel assemblies have an enrichment of 2.4 w/o. They are replacements for four once burned fuel assemblies i

that had degraded fuel rodsi By comparison, Cycle 5 utilized 80 fresh fuel assemblies with i

enrichments of 4.4 and 4.8 w/o with a similar 2.6 w/o axial annular blanket configuration.

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. Fresh assemblies for this cycle are Vantage 511 ZlRLO. This design utilizes ZIRLO for fuel clad, control rod guide tubes and instrument thimbles and Zircaloy-4 for the six low pressure drop mid grids. The mechanical design is identical to the Cycle 5 design which utilized the Inconel protective bottom grid.

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3.0 -- LOW POWER PIIYSICS TESTING

SUMMARY

Testing was performed in accordance with the following general sequence:

1 Initial Criticality: Criticality was achieved using a controlled withdrawal of the Control banks once all the Shutdown banks had been withdrawn.

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2. Zero Power Test Range Determination: This was determir.ed after the point of adding

heat had been demonstrated. Additional emphasis was placed on this measurement to

prevent testing too low in the test range, thus minimizing gamma contribution to the L excore signal.

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3. On-line Verification of the Reactivity Computer: This was detennined using stable startup rates du.'ing flux doubling measurements.

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4. Boron Endpoint Measurement: This was determined with all the Control and Shutdown banks withdrawn and again with only the Control banks inserted.

5. Isothcnnal Temperature Coefficient Measurement (lTC): This was determined from the reactivity change measured during a Reactor Coolant temperature change. The Moderator Temperature Coefficient (MTC) was calculated from the ITC Data.

6. Rod Worth Measurement: Individual Control Bank wcrths were measured during rod insertion.

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. l 4.0 POWER ASCENSION TESTING

SUMMARY

c . Testing was perfonned_ at- specified power plateaus of 30%, 50%, 75%, 90%_ and 100%

l . Rated Thermal Power (RTP). Power changes were governed by operating procedures and-L fuel preconditioning guidelines specified by the fuel vendor, Westinghouse.

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

j- :50L 90% and 100% RTP using the Fixed Incore Detector System. The resultant' peaking

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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 C

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

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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.

g 2. RCS Delta-T Indication: The initial scaling of RCS AT was left the same as' Cycle 5. At 90% RTP, aemal full power AT was extrapolated out using data fro.n 30E 50%,75%

and 90% and AT was rescaled accordingly. Final adjustments were performed at 100%

RTP.

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3. Upper Plenum Anomaly: In early 1992, Westinghouse notified North; Atlantic.that-Seabroek Station may be susceptible to a phenomenon known as- the Upper Plenum Anomaly _(UPA). The UPA is primarily characterid by a periodic step changes of 1*F to 2*F in hot leg temperature. A Design _ Document was prepared at that time to.

- implement a number.of operating contingencies should the UPA be present. Cycle 6 data -

collected at 100% RTP identified the presence of UPA for RCS loops 2 and 3. ~ Revised Tuor Average Scaling (RTAS) was not implemented.

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

Evalua: ions for Delta-T ( F), Tavo Deviation Alarm Setpoint and T A va / Tars Indication  ;

were performed.

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 perforned.'

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

Evaluations for deviations betwe(n redundant channels on individual steam generators were performed.

7. Turbine Impulse Pressure (Tarr): The initial scaling of impulse pressure was left the same as Cycle 5. Impulse pressure was evaluated at the 75% and 90 % RTP plateaus to determine if the existing scaling would support continued power increase. The Cycle 6 full power value was within 4 PSIG of the initial scaling value. The need for rescaling to the Cycle 6 full power value is being evaluated.

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

9. RCS Flow: 'A primary heat balatee was performed at 90% RTP to determine total RCS flow. The measured flow was coirected for the effects of RCS " hot leg temperature streaming" using Westinghouse methodology [WCAP-145-11]. 1 The power ascension test program required no major changes from Cycle 5. 1

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$.0 'RFSULTS

1. Low- Power Physics Testing: The acceptance and review criteria were revised per

' Westinghouse letter 94 NA#-G-0030, Recommended Westinghouse Physics Test Results.

The acceptance criteria and review criteria were met. See Table 1 for results.

2.- Flux Mapping: No problems were identified during the flux maps a: 30%,50%,90%

and 100% RTP. See Table 2 for results.

3. Full Power Thermal /Ilydraulic Evaluation: No problems were encountered with the  ;

instrumentat:an. An Upper Plenum-Anomaly was identified, however, RTAS was not-implemented. See Table 3 for results.

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TABLE 1 LOW POWER PHYSICS RESULTS CYCLE 6 ITEM- MEASURED PREDICTED ERROR CRITERIA -

- CONTROL BANK D POSITION 174 steps 116 steps 166 pcm 1500 pcm AT CRITICALITY BORON END POINTS:

• - Al.L RODS OUT 2096 ppm 2138 ppm 257 pcm i 1000 pcm o CONTROL BANKS INSERTED 1622 ppm 1632 ppm 62 pcm 2 500 pcm *

- ALL RODS OUT ITC- (pcm/*F) -2.45 -1.80 0.65 i 2*

ALL RODS OUT MTC (pcm/*F) -0.81 -0.14 N/A < l.16**

CONTROL BANK ROD WORTilS: (pcm)

• D 426 401' 25 i 100*

'e .C 918 942 24 2 141*

• B- 920 951 31 i 142*

• A 845 842 3-- i 126*

'o TOTAL 3109 3136 27 2 2822

• 314 NOTE:

• Review criteria, all others are acceptance criteria.

• • COLR limit is 1.16 at BOC (1.35 is the max over the entire cycle).

TABLE 2 POWER ASCENSION FLUX MAP RESULTS CYCLE 6 1

ITEM MAP 1 MAP 2 MAP 3 MAP 4

. DATE OF MAP . 06/29/97 06/30/97 07/02/97 07/02/97 POWER LEVEL (%) 29.5 47.6 91.2 100.0 CONTROL BANK D POSITION (steps) 169 191 210 225 RCS BORON (ppm) 1888 1774 1544 1480 Fo- 2.3419 2.2346 1.9272 1.8952 Fm 1.6453 1.5999 1.5368 1.5200 INCORE TILT 1.0178 1.0185 1.0170 1.0169

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TA BLE 3 FULL POWER THERMAL-IIYDRAULIC DATA: CYCLE 6 ITEM VALUE REACTOR COOLANT T4va 586.05 *F REACTOR COOLANT DELTA-T:

• LOOP 1 57.46 *F

= LOOP 2 57.61 F

= LOOP 3 57.19 F e LOOP 4 57.96 *F REAGOR COOLANT FLOWS: (corrected for hot leg streaming affects)

. LOOP 1 100745 GPM

= LOOP 2 99559 GPM e LOOP 3 103971 GPM e LOOP 4 99695 GPM e TOTAL 403969 GPM AUCTIONEERED 111G11 TAvo 587.13 *F Tatr 587.I8'F TURBINE IMPULSE PRESSURE 669.7 PSIG STEAM GENERATOR PRESSURES:

• A 970.5 PSIG

= B 968.4 PSIG

= C 970.I PSIG

= D 967.9 PSIG 9