IR 05000336/1986031

Insp Rept 50-336/86-31 on 861208-17.No Violations Noted. Major Areas Inspected:Startup Physics Testing Following Cycle 8 Refueling,Including Test Program,Precritical Tests & Low Power Physics Tests

ML20212Q465
Person / Time
Site:	Millstone
Issue date:	01/15/1987
From:	Petrone C, Wen P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20212Q423	List: IR 05000336/1986031 ML20212Q420
References
50-336-86-31, NUDOCS 8702020266
Download: ML20212Q465 (8)

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- j U.S. NUCLEAR REGULATORY COMMISSION  ;

REGION I

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Report N /86-31 Docket N !

License No. DPR-65 e

Licensee: Northeast Nuclear Energy Company P. O. Box 270 Hartford, Connecticut 06141-0270 Facility Name: Millstone Unit 2 l Inspection At: Waterford, Connecticut Inspection Conducted: December 8-17, 1986 Inspectors: /4 (* ltds //M-/17 -

P. C. Wen, Reactor Engineer date *

Approved by: d bwe ,//sM/7 l C. Petrone, Chief, Test Program Section, ~date 08, DRS Inspection Summary: Inspection on December 8-17, 1986 (Inspection Report N /86-31).

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Areas Inspected: Routine, unannounced inspection of startup physics testing following refueling of Cycle 8. The inspection included the test program, '

pre-critical tests, and low power physics test Results: No violations were identifie !

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DETAILS 1.0 Persons Contacted

R. Bigelow, Nuclear Fuels Supervisor (NUSCO)

• Borchert, Acting Reactor Engineer i

P. Hoffspiegel, Test Engineer (CE)

T. Itteitag, Assistant Chemistry Supervisor i *J. Keenan, Unit 2 Superintendent S. Long, Test Engineer (CE)

W. Ross, QC Engineering Specialist

! J. Smith, Operations Supervisor l C. Stafford, Test Engineer (CE)

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T. Rebelowski, Senior Resident Inspector

" Denotes those present at the exit interview on December 16, 198 I The inspector also contacted other licensee employees in the course of I the inspectio ! 2.0 Cycle 8 Reload Safety Evaluation and Core Verification l The Cycle 8 reactor core is comprised of 217 fuel assemblies (FAs).

During the Cycle 7/8 refueling, 64 fresh FAs (Batch K) were loaded into the core. The remaining 153 FAs were from previous cycles operatio Among those, 8 FAs (1-Batch F and 7-Batch G) were reconstituted from fuel assemblies that were prematurely discharged due to fuel f:tilure af ter the i Cycle 5 operation. The major change in Cycle 8 operation also included 1 replacing of 16 Control Element Assemblies (CEAs). The licensee and its

, fuel vendor (Westinghouse) performed the required safety evaluation in

association with these Cycle 8 related changes, and concluded that there I

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were no unreviewed safety questions. The inspector reviewed the Cycle 8 reload design change package (PDCR No. 2-70-86), and noted that these changes did not alter the previous reference Cycle's safety analysis

! result The basic assumption used in the Cycle 8 reload safety evaluation was Cycle 7 burnup of 11,700 MWD /MTV. The inspector verified the actual Cycle i

7 burnup to be 11,547 MWD /MTU. The assumptien is thus valid.

j Through radiochemistry data trend review and discussion with the reactor i engineer, the inspector noted that the Cycle 7 fuel performance was ( satisfactorily. Consequently, there are no known leaking fuel assemblies being loaded into the Cycle 8 core.

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The inspector reviewed one-half of the core verification videotapes and verified that the as-loaded core agreed with the intended core loading plan (Westinghouse Drawing No. 1840E90, " Millstone II Core Loading Plan Cycle 8," Revision 2).

No unacceptable conditions were identifie .0 Cycle 8 Startup Testing Program The startup test program was conducted according to test procedures T86-15, " Initial Criticality / Low Power Physics Test-Cycle 8" and T86-16,

" Power Ascension Test - Cycle 8". . The test sequence outlined the steps in the testing program, set initial conditions and prerequisites, speci-fied calibration or surveillance procedures at appropriate points in the test sequence, and referenced detailed test procedures and data collection in appendices. Initial criticality of Cycle 8 was achieved on December 14, 1986. The Low Power Physics Tests (LPPT) were completed on December 17, 1986. Preliminary evaluation indicated that all LPPT results met acceptance criteria. The Power Ascension Tests will be conducted when the unit reaches to an appropriate power leve The inspector independently verified that the predicted values and accep-tance criteria were obtained from "The Nuclear Design and Core Management of the Millstone Nuclear Power Station Unit No. 2 Cycle 8," WCAP-1126 The inspector witnessed most portions of the LPPT and reviewed test re-suits and documents described in this report to ascertain that the post startup testing was conducted in accordance with technically adequate procedures and as required by Technical Specifications (TS). The detailed findings of the review are described in Sections 4 and .0 Cycle =d, Start-up Testing - Precritical Tests The inspector reviewed calibration and functional test results to verify the following:

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Procedures were provided with detailed instructions;

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Technical content of procedure was sufficient to result in satisfactory component calibration and test;

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Instruments and calibration equipment used were traceable to the National Bureau of Standards;

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Acceptance and operability criteria were observed in compliance with T .

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i The following tests were reviewed:

4.1 CEA Drop Time

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The CEA drop time measurement was. performed in accordance with Test Procedure SP21010, "CEA Drop Times," Revision 1, on December 12,

1986. CEA drop times were measured at hot full flow conditions. The l process computer timing mechanism was utilized'to measure the CEA drop times. To qualify this process computer timing method, test

runs using visicorder trace were also performed in parallel for one

(1) rod in each CEA group. The inspector reviewed several visicorder

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traces and process computer timing results, and noted that the re-

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suits from both methods showed good agreement. All 61 CEAs met the TS drop time surveillance requiremen .2 Reactivity Computer Setup / Verification Both reactivity computers (General Atomic and Combustion Engineering)

were set up and calibrated according to procedure EN?1004, "Reac-tivity Measurements," Revision 3, prior to reaching criticality. The inspector verified that the reactivity computers were adjusted with j the correct inputs of delayed neutron fractions (betas) and decay ,

constants (lambdas), and noted that the results of " cold" calibration check using doubling time method were satisfactory.

i Both reactivity computers were further checked when the reactor was critical on,. December 14, 1986. Comparisons of predicted and measured reactivities based on a given startup rate were acceptabl The GA reactivity computer was initially being used as an official i  : reactivity computer for the LPPT measurement. However, during the

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Isothermal Temperature Coefficient (ITC) measurement at all rods out condition which was the first test of LPPT, a discrepancy was shown between the computer digital. display and strip chart recorde The GA reactivity computer was declared inoperable, and the CE

' reactivity computer was brought in for us The ITC measurement at all rods out condition test was repeated at the end of LPPT on December 16, 1986. Therefore, all LPPT test data i were derived from the qualified CE reactivity compute No unacceptable conditions were identifie .0 Cycle 8, Startup Testing - Post-Critical Tests i

The inspector reviewed selected test program to verify the following:

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The test programs were implemented in accordance with the approved i procedures; I

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Step-wise instructions of test procedures were adequately provided including Precautions, Limitations and Acceptance Criteria in con-formance with the requirements of the TS;

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Provisions for recovering from anomalous conditions were provided;

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Methods and calculations were clearly specified and the test was performed accordingly;

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Review, approval, and documentation of the results were in accordance with the requirements of the TS and the licensee's administrative control .1 Critical Boron Measurements The licensee measured the critical boron concentration in accordance with the procedure specified in T86-15, Sections 7.5 and 7.10. The inspector noted the following result Predicted Measured Confiouration Value (ppm) Value (ppm)

All Rods Out (ARO) 1207 85 1217 CEA Groups 7 thru 795 85 817 2 Full In Test results were within acceptance criteri .2 Isothermal Temperature Coefficient (ITC)

ITCs were measured in accordance with procedure specified in T86-15, Sections 7.7 and 7.11. The inspector noted the following result Predicted Value Measured Value Configuration (pcm/ F) (pcm/ F)

ARO .0 1.89 Groups 7-2 In - .0 -7.30 The measured ITC (f.20) was based on an average RCS temperature of 528.4 F, and an RCS baron concentration of 1222 ppm, while the predicted value is based on 532 F and 1207 ppm. The following is the inspector's independent verification:

The AITC temperature adjustment from 532 F to 528.4 F is: 0.031 !

pcm/ F/ F *(532 - 528.4) *F = 0.11 pcm/ j I

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The AITC boron adjustment from 1207 ppm to 1222 ppm is: 0.011 pcm/ F/ ppm * (1222 - 1207) ppm = 0.17 pcm/ Therefore, the predicted ITC value based on the actual test conditions is 1.8 + 0.11 + 0.17 = 2.08 pcm/ The difference between the measured and predicted values is 2.08 - 1.89 = 0.19 pcm/ F, and this value is within the acceptance criteri The inspector noted that the actual test condition (530.1 F, 817 ppm) for the CEA Groups 7-2 In case was close to the predicted condition (532 F, 795 ppm). The AITC adjustment is believed to be minor, and the test result is within the test acceptance criteri The calculated Moderator Temperature Coefficient (MTC) from the ITC measurement is:

MTC TS Limit Conditions (pcm/ F) (pcm/ F)

ARO/HZP/BOL 4.23 <5

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Test results were within the acceptance criteri .3 CEA Worths The CEA Worth measurements were performed in accordance with the Procedure T86-15, Sections 7.9 and 7.12. The licensee conducted individual group Worth measurements using conventional boron dilution techniques and overlap group CEA Worth measurements using the boration method. The inspector witnessed portions of the test and observed that all surveillance requirements associated with entering TS special test exceptions were properly performed. The following test results were obtained:

Dilution Method CEA Measured Predicted Acceptance Group (% Arho) (% Arho) Criteria 7 .845 .832 0.1% arho or 15% difference 6 .439 .427 "

5 .238 .232 "

4 1.068 1.101 "

3 0.548 0.560 "

2 1.236 1.173 "

Total 4.374 4.325 Within i 10%

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Boration Method CEA Measured Predicted Acceptance Group (% Arho) (% Arho) Criteria 2 1.229 1.173 0.1% Arho or

1 15% difference 3 0.54 0.560 "

4 thru 7 2.548 2.592 Within i 10%

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Total 4.317 4.325 Within 10%

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Test results were within the acceptance criteria.

I 5.4 CEA Symmetry Checks The licensee performed CEA Symmetry Checks in accordance with the Procedure T86-15, Section 7.8. Responses from the rod swaps among a

selected CEA group were evaluated to determine any unexpected flux

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til Rods in CEA Groups 3, 1, A, and B were selected for this, f tes The calculated deviations of any CEA from its group average

were all within the acceptance criteria of 2.5c reactivit Test results indicate that the Cycle 8 core contains no excessive flux tilt.

i 6.0 Independent Calculations / Verifications The inspector performed independent calculations / verifications of Cycle 8 startup physics testing related activities. These included the following:

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Core loading verification as described in Section ,

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Test acceptance criteria verification as described in Secticn 3.

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Independent engineering calculations as described in Section . QA/QC Interface Through document review and discussion with a QC Engineering Specialist, the inspector noted that QA/QC had performed surveillance in reactor engineering activities including; new fuel inspection,' core shuffling witnessing, and final core loading verification. All nonconformance items identified by the QC inspector in these activities were resolved.

' The startup physics testing audit work is traditionally conducted by the NUSCO QA group. Because the Cycle 8 startup testing is still in progress j during this inspection period (December 8-17,1986), this audit has not been performe i No unacceptable conditions were identifie . . . . . . .- - ., . ._ .. -. .

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8.0 Exit Interview L1censee management was informed of the purpose and scope of the inspection at the entrance intervie The findings of the inspection were periodically discussed and were summarized at the conclusion of the inspection on December 17, 1986. Attendees at the exit interview are denoted in paragraph 1. Based on the NRC Region I review of this report and discussions held with licensee representatives at the exit interview, it was determined that this report does not contain information subject to 10 CFR 2.790 restriction No written material was provided to the licensee by the inspector at any time during this inspection.

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