ML20067C085

Cycle 5 Startup Physics Test Summary

ML20067C085
Person / Time
Site:	Grand Gulf
Issue date:	02/02/1991
From:	Cottle W ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GNRO-91-00016, GNRO-91-16, NUDOCS 9102110187
Download: ML20067C085 (7)

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W. T. Cottle we %3n C-g ery4 4r;

.CnsiGW*1ur twsn February :2, i1991 U.S. Nuclear Regulatory Commission Mail Station P1-137 Washington, D.C. . 20555 Attention: Document Control Desk'

SUBJECT:

-Grand Gulf Nuclear' Station .

Unit 1 Docket No. 50-416 License No. NPF-29 Post RF04 Startup Test Report q GNRO-91/00016 Gentlemen:

Entergy Operations, Inc. is transmitting, with this letter, the Grand Gulf ,

'NuclearStation(GGNS) Unit.1PostRefuelingOutage-4-(RF04)-StartupTest Report. This report'is ser.t in compliance with the requirements of Grand Gulf lechnical Specifications 6.9.1.1, 6.9.1.2, and 6.9.1.3.

The'startup physics testing was completed on-December 3,.~1990. The attached report provides a summary of each test and the results where applicable.

If further information-is required, please contact this office.

Yours truly,

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February 2, 1991 GNRO-91/00016 Page 2 of 3 i

cc: Mr. D. C. Hintz (w/a)'.

Mr. R. B. McGehee.(w/a)_

Mr.N.'S.Reynolds:(w/a)

Mr. H. L.. Thomas (w/o)

Mr. J. L. Mathis (w/a) >

Mr.StewartD.Ebneter(w/a)

Regional Administrator-U.S. Nuclear Regulatory Commission ,

Region II- . .

-101 Marietta St. , N.W., Suite 2900_

Atlanta, Georgia 30323; Mr.- L _ L. Kintner, Project Manager-(w/a) ~ a Office of Nuclear Reactor Regulation J U.S. Nuclear Regulatory Consission Mail Stop 11021 '

Washington, D.C. 20555 4

1 i RF04RPT/SCMPFLR

Grand Gulf Nuclear Station Unit 1 Cycle 5 Startup Physics Test Summary Grand Gulf Nuclear Station (GGNS) resumed commercial operation for Cycle 5 on November 26, 1990 following a Refueling / Maintenance Outage. The Cycle 5 reload consisted of-replacing 284 Advanced Nuclear Fuels (ANF) 8X8 fuel assemblies with 284 ANF 9X9 fuel assemblies. These startup tests were performed during RF04 and while attaining full power after RFO4 and are summarized in this report:

1) Core Loading Verification

2) Control Rod Functional Testing

3) Shutdown Margin Determination

4) TIP Asymmetry the startup test In addition program to the above included: startup physics Core Monitoring System tests,ication, Verif Neutron Monitoring System Response, Recirculation System Calibration, and other surveillance testing as required.by GGNS Technical Specifications. The additional test results are available c.t the site on request.

Startup' Physics TestL11L Core Loading' Verification Purpose Ensure each reactor fuel assemblyL ist in its correct-core location, oriented properly,-

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andfseated properly-in its' support piece. Li criteria The reactor core-is visually checked;to verify conformance to'the vendor supplied core loading pattern. Fuel assembly serial numbers, orientations, and-core locations are recorded.- A height-check is performed to verify all assemblies are properly; seated.

Results The ANF- Cycle 5 core loading pattern wasimodified' after a fuel, movement incident which resulted in a bundle being rendered unusable. The unusable bundle was replaced by a: discharged bundle that had a similar exposure history.

The as-loaded core was verified for proper = fuel-assemblyLserial:

numbers locations,' orientation, and seating in accordance with-the modified ANF Cycle 5, core loading pattern. The core verifi-cation procedure was successfully-completed onLNovember 2, 1990.

l Startup Physics Test #2 Control Rod Functional Testing Purpose i Verify operability of each control rod by:-

normal withdrawals and insertions, ensuring it is latched to its control rod drive, and moves at design speeds without excessive friction.

Criteria Functional testing of each control rod is performed to ensure proper operability. This testing includes withdrawal and-insertion timing, coupling verification, friction testing where required and scram time testing.

Results Each control rod was verified operable before~the Reactor Vessel Operational Hydro Test.

A control rod coupling check was performed in-accordance with GCNS Technical Specification surveillance requirement 4.1.3'.4 each time a control rod was fully withdrawn.

Each individual control rod was timed during a normal withdrawal and insertion sequence. Control rods with stroke times outside the tolerance of normal stroke time + 20% were readjusted to within normal stroke time + 10%. - ThTs was in accordance with GE recommendations.

Eighteen control rod drives were replaced during RF04. Each of these control rods were tested for excessive friction. None of the control rods indicated abnormal friction.

Each control rod was scram time tested during the Operational l

Hydro-Test or reactor startup in accordance with GGNS Technical specification surveillance requirement 4.1.3.2. All of the-control rod scram times were within the allowable'11mits.

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Startup Physics Test #3 Shutdown Margin Determination Purpose To ensure: i

- the reactor can be made subcritical from all operating conditions, the reactivity transients associated with postulated accident conditions are controllable within acceptable limits,

- the reactor will be maintained sufficiently subcritical to preclude inadvertent criticality in the shutdown condition.

Criteria Control rods are withdrawn in their standard sequence until criticality is achieved. The shutdown margin of the core is determined from calculations based on the critical rod pattern, the reactor period, and the moderator temperature. To ensure no reactivity anomaly exists, the actual critical control rod positions will be verified to be within 1% delta k/k of the predicted critical control rod position.

Results gg The in-sequence critical shutdown margin surviellance procedure was completed on November 24, 1990.

The Cycle 5 minimum shutdown margin (SDM) at the beginning-of-cycle (Boc) was calculated to be 0.837% delta k/k (R value is equal to 0) which was well within GGNS Technical Specification 3.1.1 requirement of 0.38% delta k/k.

The calculated reactivity difference between the actual and predicted SDM was 0.33% delta k/k which was well within GGNS-l Technical Specification 3.1.2 requirement of 1% delta k/k.

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, Startup Physics Test #4 TIP Asymmetry Check Purpose Verification that the observed variance in integral MICROBURN-calculated TIP responses at GGNS is statistically consistent with the variance of the integral TIP measurements used in ,

i ANF's Neutronics Methods for Design and Analysis. l Criteria A gross as p etry check is performed as part of a detailed i statistical uncertainty evaluation of the TIP System. A I complete set of TIP data is obtained at steady state conditions while greater than 65% rated power. A total  !

average deviation or uncertainty is determined for all, I symmetric TIP pairs as well as the maximum absolute deviation.

The results will be evaluated to assure proper operation of the TIP System and symmetry of the core loading.

1 Results The TIP Reproducibility and Symmetry Uncertainty calculations were performed on December 03 1990 at a reactor core thermal power of 100%. A total of fs..r Chi-squared tests were performed.

The first consistency test examined the variance in the combined measured and calculated integal TIP data. The second consistency test-evaluated variance in the measured integral TIP responses for symmetric locations. The third and fourth test repeated the first two tests on a planar basis by renormalizing the nodal TIP distribution to unity within each plane separatel distributions. y for both the measured and calculated TIP The results of the four tests are as follows:

Test Chi-Squared Value Critical Value 1 7.38 60.48 2 2.26 30.14

. 3 151.37 950.13 4 38.92 426.46 All of the Chi-squared values were much less than the Critical values indicating no TIP Assymmetry exists.

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