ML20138M242

Sser Re Power Ascension Test Program Acceleration.Change Acceptable Except for Elimination of Testing at Test Condition 4.Justification for Deleting Testing at Test Condition 4 Insufficient

ML20138M242
Person / Time
Site:	Hope Creek
Issue date:	12/16/1985
From:	NRC
To:
Shared Package
ML20138M241	List: ML20138M237 ML20138M242
References
NUDOCS 8512200311
Download: ML20138M242 (4)

Text

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o,, UNITED STATES o NUCLEAR REGULATORY COMMISSION

,a WASHINGTON, D. C. 20555

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SUPPLEMENTAL SAFETY EVALUATION INPUT HOPE CREEK GENERATING STATION POWER ASCENSION TEST PROGRAM ACCELERATION This is the second of a series of test program changes submitted for approval as part of the program to accelerate power ascension testing for the Hope Creek Generating Station. Hope Creek accelerated power ascension testing also has become the lead plant for generic changes for acceleration to the traditional General Electric (GE) Company's Boiling Water Reactor (BWR) power ascension test program.

The requested changes were submitted by letter from R. L. Mittl, Public Service Electric and Gas Company, (PSE&G), to W. Butler, NRC, dated September 20, 1985. These changes are as follows:

1. Deletion of tuning of Reactor Core Isolation Cooling System (RCIC) controllers at low reactor pressures, Final Safety Analysis Report (FSAR) subsection 14.2.12.3.12.

, 2. Deletio' '" tuning of the High Pressure Coolant Injection System (HPCI) controll e s at low reactor pressures, FSAR subsection 14.2.12.3.13.

3. Substitution of the Technical Specification surveillance testing for the Selected Process Temperatures power ascension test, FSAR subsection 14.2.12.3.14. This test assures that idle recirculation loop temperature differentials are within Technical Specification limits before restarting the pump and confirm that pump lower limits are sufficient to prevent temperature stratification in the reactor

. pressure vessel lower head region.

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4. Delete response checks of the Local Power Range Monitors (LPRM) to control rod movements during plant heatup and Test Condition 1 for the LPRM Calibration, FSAR subsection 14.2.12.3.9.

5. Delete all testing at the natural circulation condition, Test Condition 4 (TC 4).

Items 1 through 5 are addressed below:

I and 2. DELETION OF CONTROLLER TUNING AT LOW PRESSURES FOR THE RCIC AND HPCI SYSTEM TESTS --

Currently, tuning of the controllers for the RCIC and HPCI is peFformed at both low pressure and near rated reactor pressure. The applicant indicates that testing experience with recently commercialized BWRs has demonstrated 11 851216 gja2QCK05000354 A

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that a best estimate controller setting may be selected from previous test data and used to bench calibrate the controllers during preoperational testing. This preliminary bench controller tuning is sufficient for low pressure testing and final tuning near rated reactor pressure. Experience at previous plants has shown that controller tuning at the low pressure condition does not result in optimum perfomance at higher pressures. The applicant is requesting deletion of controller tuning at the low reactor pressure condition, relying on controller tuning or optimization at or near rated reactor pressure. Testing at low reactor pressure with the rated reactor pressure controller setting will be completed to confirm acceptable, but, perhaps, less than optimized system performance at low pressure conditions.

The staff has reviewed the applicant's requested change to the method of testing these two systems. The staff recognizes that it would be unlikely that operation of these two systems could be optimized over the entire pressure range for which they are expected to operate. Selecting rated pressure conditions for the point of optimization is reasonable and acceptable to the staff because acceptable operation at low reactor pressure will be confimed with the rated pressure controller setting.

3. SUBSTITUTION OF TECHNICAL SPECIFICATION SURVEILLANCE TEST OF STARTUP OF AN IDLE REACTOR RECIRCULATION LOOP FOR PORTIONS OF THE SELECTED PROCESS TEMPERATURES AND DELETE DETERMINATION OF LOW PUMP SPEED LIMIT The applicant is requesting the substitution of the Technical Specification surveillance test for startup of an idle reactor recirculation loop for portions of the selected process temperatures startup procedure and deletion of determination of the low pump speed limit by utilizing a fixed value established from results of this test on previous plants.

The staff has previously discussed the acceptability of utilizing Technical Specification surveillance testing as data taking sections of initial

- startup test procedures where applicable in our memorandum to T. M. Novak, ,

, . DL, from D. L. Zeimann, DHFS, dated October 11, 1985 and find this l requested substitution acceptable. The Region staff will confirm during future test procedure review that the surveillance test has been properly incorporated into the procedure and that all necessary test data will be obtained.

The staff found that the request to delete the determination of the low pump speed limit in favor of using a fixed limit derived from previous plant tests was not supported by sufficient information. The applicant supplied additional information on the startup testing for the Brunswick Steam Electric Plant, Unit I and Edwin T. Hatch, Unit 2 which was reviewed by the staff. This information was contained in the Final Summary Report -

Edwin I. Hatch Unit 2 - Startup Test Results, NED0-24734, R. W. Turkowski and W. Yee, October 1979 and Brunswick Unit 1 - Startup Test Resiilts - 1 Final Summary Report, NED0-24562, I. D. Poppel, November 1977. This  :

additional information and regulation mandated startup reports of other l

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plants were reviewed and allowed the staff to confirm that a fixed low pump speed limit could be selected based on previous plant testing which assures adequate coolant mixing and, therefore, acceptable temperature differentials in the lower plenum.

4. DELETION OF RESPONSE CHECKS OF THE LOCAL POWER RANGE MONITORS (LPRM) TO CONTROL ROD MOVEMENTS DURING PLANT HEATUP AND TEST CONDITION 1 The applicant has requested that their planned response checks to control rod movements during heatup and Test Condition 1 be deleted for the LPRM calibration test, 14.2.12.3.9, because many of the LPRM detectors do not have usable signals at low power levels due to low flux levels.

The staff notes that this is a level of detailed implementation which does not appear in the FSAR test abstract, but may be reviewed at the regional level in the detailed procedure. The staff recognizes that early confirmation of control rod movement and proper installation of the LPRM detector is valuable when the detector output is in its useful range.

However, until the threshold of usefulness is attained, checks of this type are of little value. Because the requested deletion does not change the test objective, summary test method or acceptance criteria of the test abstract, the staff finds the proposed changes conceptually acceptable.

5. DELETION OF TESTING AT THE NATURAL CIRCULATION CONDITION, TEST

CONDITION 4

. The applicant requests deletion of all testing at Test Condition 4 l (approximately 50% power and 30% core flow) based on the stated premise that the applicant does not intend to operate in this domain of the power / core flow map and that the only way this domain would be approached l would be an abnormal operational transient (trip of two recirculation l pumps) and resulting natural circulation. The plant technical

, specifications require that with no reactor coolant system recirculation loops in operation, the operator must take immediate action to reduce l thermal power to less than or equal to that allowed by the Core Thermal Power to Core Flow Map within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and, further, the operator must take

, action to place the plant in at least startup within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Therefore, l the applicant states that testing need not be done at Test Condition 4.

The staff felt that the applicant's justification for deleting testing at  !

Test Condition 4 was inadequate. The reactor manufacturer, GE submitted additional discussion to supplement the applicant's justification by letter from J. F. Klapproth, GE, to R. A. Becker, NRC, dated November 6,1985. The staff included this information in addition to the applicant's gubmission in its review. ..

The staff finds that the justification for deleting testing at Test Condition 4 is insufficient. The staff considers that the tech 61 cal specifications define the "possible operating modes" whether or not, the i, , . . -

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applicant foresees their utilization at the commencement of the plant's 40 4

- year life. The length of time allowed at or near natural circulation is long compared to phenomenon ~which could generate a safety concern such as stability. The staff agrees with the applicant that .the generic natural

' circulation and stability have been sufficiently confirmed in recent

. domestic and foreign commercialized BWRs. However, the staff believes.the testing encnmpassed by. Regulatory Guide 1.68, Appendix A, Section 5, third

' introductory paragraph refers to plant specific confirmatory testing and

' Test Condition 4 represents one of the " extremes of possible operating -

modes" referred to in the Regulatory Guide. Therefore, thorough testing dictates equipment specific testing at the natural circulation, Test Condition 4 and the staff finds the elimination of_ testing at Test

Condition 4 to be unacceptable.

Principal Contributor

R. A..Becker

Dated: December 16, 1985 j

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