ML20154H217

Safety Evaluation Accepting Util 880414 Submittal Re Reload Startup Physics Test Program

ML20154H217
Person / Time
Site:	Mcguire, Catawba, McGuire, 05000000
Issue date:	05/18/1988
From:	Office of Nuclear Reactor Regulation
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ML20154H185	List: ML20154H181 ML20154H217
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NUDOCS 8805250266
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• ENCLOSURE SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO RELOAD STARTUP PHYSICS TEST PROGRAM DUKE POWER COMPANY HCGUIRE NUCLEAR STATION, UNITS 1 AND 2 CATAWBA NUCLEAR STATION, UNITS 1 AND 2 DOCKET NOS. 50-369 AND 50-370 DOCKET N05. 50-413 AND 50-414

1.0 INTRODUCTION

By letter dated February 2,1988, Duke Power Company (DPC), the licensee for the ficGuire and Catawba Nuclear Stations, Units 1 and 2, submitted a startup physics test program which would be used for plant cycle startup following a refueling cutage. The purpose of the submittal was to formally document the minimum reload physics tests necessary to ensure that the reactor core can be operated as designed. DPC states that there were no significant changes in the proposed physics test program to that currently being performed following refueling at the four units. NRC approval was requested because the proposed reload startup physics program was intended to replace the initial cycle physics test program described in the FSARs.

The DPC startup physics test program is modeled primarily after the ANSI /ANS 19.6.1-1985 standard on reload start-up tests for PWRs. This standard has been extensively reviewed by the staff, as well as others, and incorporates the changes and views suggested by the staff. By letter dated April 18, 1985, this standard was approved with comments by the NRC staff member on the American flational Standards Comittee N17 on Research Reactors, Reactor Physics, and Radiation Shielding. The standard ANSI /ANS-19.6.1 1985 currently serves as the staff guidance on the minimum startup physics test program for a PWR following a refueling outage, kk P

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The staff performed an initial review of DPC's February 2,1988 subnittal l and by letter dated March 11, 1988, informed DPC that the proposed startup i physics test program was unacceptable. A telephone conference call was held on March 24, 1988 to discuss the dental and to identify the means for resolving the staff's concerns. Subsequently, DPC resubmitted its proposed startup i physics test program by letter dated April 14, 1988. j i

The staff's evaluatien of the proposed DPC startup physics test program, as resubmitted, follows. ,

2.0 EVALUATION -

Because DPC's proposed startup physics test program is modeled after the j ANSI /ANS-19.6.1-1985 standard on reload startup physics tests for PWRs and {

because this standard provides acceptable guidance on such tests for the staff. I our review and evaluation of DPC's test program was performed on the basis of )

confornance to the standard. The staff's evaluation of each proposed test f' follows+

A. Critical Boron Concentration Measurement - All Rods Out DPC has changed the description of the tests initial condition which states that the lead test bank should be inserted to less than 20 inches in the core to state that the lead test bank should be near fully withdrawn. DPC states that this limits the inserted reactivity to the verified measurement range of the reactivity cor.puter (typically + 0.00055 j delta rho for positive reactivity insertions) ratNr than to an arbitrary bank position. This change is acceptable since it meets the intent of standard ANSI-19.6.1-1985.

The staff concludes that the initial conditions, the test method, and acceptance criterion are consistent with the standard and, therefore, this test is acceptable.

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I' B. Isothermal Temperature Coefficient j 1

l The staff concludes that the initial conditions, the test method, and i I

] acceptance criterion are consistent with the standard and, therefore, J

this test is acceptable. ,

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C. Control Rod Bank Worth j By letter dated May 22, 1987, the NRC had previously approved OPC's rod i swap nethodology based upon a two-level set of criteria: (1) review criteriaessociatedwithmeetingdesigncriteriaand(2) acceptance

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criteria associated with meeting safety analyses assumptions. The review l criteria correspond to the recomended test criteria of the ANSI /

j ANS-19.6.1-1985 standard. OPC states that if a review criteria is missed, ,

j remedial action will be taken based on the NRC's May 22, 1987 Safety l j Evaluation Report on DPC's rod swap methodology. These review and  !

i acceptance criteria are acceptable since they meet the intent of the )

ANSI /ANS-19.6.1-1985 standard. l f

The staff concludes that the initial conditions, the test method, the

review and acceptance criteria, and the fact that all control and shutdown i batiks will be measured, constitute an acceptable control rod bank worth f test program in accordance with the standard and this test is, therefore, av eptable, i

O. Flux Symetry Check Low Power DPC has changed the upper power level limit of this test from the 30%

recomnended by the ANS!/ANS-19.6.1-1985 standard to 40% of full rated l

j thermal power. We find that this is acceptable because moderator J

feedback effects in going from 30% to 40% power are not expected to affect

, significantly any power distribution asymmetries. This change is desired by DPC to improve scheduling flexibility of testing during the refueling j outage.

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i Rather than using synnetric core locations for performing the test, OPC ,

uses all operable instrumented locations and compares measured to i

predicted values of F N H or normalized reaction rates. This change to  ;

1 the test method is required due to the limited nuriter of quarter core l 1

symmetric instrumented locations and the use of a novable fission l

detector.  :

I j The staff concludes that both of the changes described above are j f acceptable since they meet the intent of the ANSI /ANS-19.6.1-1985 i i standard with regard to the flux synnetry test at low power. The initial corditions, the test method, and acceptance criteria are consistent with ,

I the standard and, therefore, this test is acceptable.  !

E. Core Power Distributien - Intermediate Power  ;

j DPC has changed the lower limit of the power range reconnended in the ANSI /ANS-19.6.1-1985 standard fren 40% to 50% power. Similarly, DPC has

! changed the upper limit from 75% to 80% power. These changes in the  !

upper and lower limits have been proposed by DPC to improve scheduling i flexibility of testing during tha **':'eling outage. Neither of these 1

changes is of any significance since the intent of the test is to measure i the core power distribution at some internediate power level with broadly j defined but arbitrary limits on the power range. Thus the DPC changes j meet the intent of the ANSI /ANS-19.6.1-1985 standard for perforaing a core i power distribution measurement at some intermediate power level.

4 j The staff concludes that the initial conditions, the test method and

{ acceptance criteria are consistent with the standard and, therefore, this l j test is ecceptable.

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F. Core Power Distribution - High Power j i

The staff concludes that the initial conditions, test method, and acceptance criteria are ici accordance with the standard and, therefore.

this test is acceptable.

G. All Rods Out Critical Boron Concentration - High Power The staff concludes that the initial conditions, test method, and )

acceptance criterion are in accordance with the standard and, therefore, this test is acceptable.

The ANSI /ANS-19.6.1-1985 standard also requires the measurement of the critical boron concentration at hot, zero power with all control rods inserted. OPC l does not explicitly include this test as part of its reload startup physics test program. However, DPC notes that this test would be performed as part i of the control rod bank worth test using the rod swap method. The staff concurs with DPC's assessment concerning this test and the changes noted when the reference bank of the rod swap method is used for the test. The staff concludes that DPC's inclusion of this test in the control rod bank worth test is acceptable because the intent of ANS!/ANS-19.6.1-1985 standard with regard to the comparison of measured and predicted differential boron worth is met.

DPC states that the reload startup physics test program is a minimum program.

Additional tests will be performed when circumstances or unusual conditions require them. This position is acceptable to the staff and conforms to current

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Industry practicts. l

3.0 CONCLUSION

S For the reasons discussed above, the staff concludes that OPC's proposed reload startup physics test program for NcGuire and Catawba Nuclear Stations, '

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linits 1 and 2 is acceptable because it meets, with the changes noted, the intent of the test program discussed in the AflS!/ANS-19.6.1 1985 standard used for staff guidance.

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