ML17306B112

Forwards Response to Request for Addl Info Re Concerns Addressed in 920514 Submittal.Review of Info Determined No Impact on Plant Safety

ML17306B112
Person / Time
Site:	Palo Verde
Issue date:	10/20/1992
From:	Conway W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
102-02316-WFC-T, 102-2316-WFC-T, NUDOCS 9211130178
Download: ML17306B112 (12)

Text

ACCELERATED DISTRIBUTION DEMONSTRATION SYSTEM REGULRY INFORMATION DISTRIBUTI SYSTEM (RIDE)

ACCESSION NBR:9211130178 DOC.DATE: 92/10/20 NOTARIZED: NO DOCKET FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 STN-50-530 Palo Ver'de Nuclear Station, Unit 3,'Arizona Publi 05000530 AUTH. NAME AUTHOR AFFILIATION CONWAYFW.F. Arizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION MARTIN,J.B. Region 5 (Post 820201)

SUBJECT:

Forwards response to request for addi info re concerns addressed in 920514 submittal. Review of info determined no impact on plant safety. D, DISTRIBUTION CODE: IEOZD 'COPIES RECEIVED'LTR r ENCL TITLE: General (50 Dkt)-Insp Rept/Notice of Violation L SIZE~

Response

NOTES:STANDARDIZED PLANT '050005/

Standardized plant. 05000529 Standardized plant. 050005~

D.

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME'RAMMELL,C LTTR ENCL D

PD5 PD 1 1 1 1 INTERNAL: ACRS 2 AEOD 1 1 AEOD/DEIB 2 AEOD/DSP/TPAB 1 1 AEOD/TTC -1 DEDRO . 1 1

.NRR MORISSEAU,D 1 NRR/DLPQ/LHFBPT 1 1 NRR/DLPQ/LPEB10 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PEPB9H 1 NRR/PMAS/ILRB12 1 1 NUDOCS-ABSTRACT 1 i 1 1 OGC/HDS1 1 G FILE 02 1 ~ 1 RGNS FILE Ol 1 EXTERNAL: EG&G/BRYCEFJ.H. 1 1 NRC PDR 1 1 NSIC 1 1 0 -.

NOTE TO ALL RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL 0

DESK.

ROOM Pl-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED! S TOTAL NUMBER OF COPIES REQUIRED: 'LTTR 24 ENCL 24

Arizona Public Service Company P.O, BOX 53999 ~ PHOENIX. ARIZONA 85072-3999 102-023]6-WFC/TRB/RKR WILLIAMF. CONWAY EXECUTIVEVICE PRESIDENT October 20,'992 NUCLEAR r

Mr. John B. Martin Regional Administrator, Region V U. S. Nuclear Regulatory Commission 1450 Maria Lane, Suite 210 Walnut Creek, CA 94596-5368

Reference:

Letter dated September 14, 1992, from K. E. Perkins Jr., Director, Division of Reactor Safety and Projects, NRC, to W. F. Conway, Executive Vice President, Nuclear,,Arizona Public Service Company

Subject:

. Palo Verde Nuclear Generating Station (PVNGS)

Units1,2, and 3 Docket Nos. STN 50-528/529/530 Reply to NRC Request for Information File: 92-070-026 The referenced letter requested Arizona Public Service Company (APS) to provide additional information for one of the concerns addressed in APS'ay 14, 1992 submittal.

Enclosed is APS'esponse to your request for additional information. A review of this information determined that there was no impact on plant safety. During a telephone conversation on October 13, 1992, between H. Wong, NRC, and T. R. Bradish, APS, an extension of the due date'for this response from October 14, 1992 to October 20, 1992, was granted.

If you have any questions, please contact Thomas R. Bradish at (602) 393-5421.

Sincerely, WFC/TRB/RKR/pmm Enclosure cc: J. A. Sloan Document Control Desk 9211130178r921020 PDR ADOCK 05000528 PDR

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ENCLOSURE REPLY TO REQUEST FOR INFORMATION

REPLY TO REQUEST FOR INFORMATION NRC BACKGROUND STATEMENT Arizona, Public Service Company (APS) letter 102-02148-WFC/TRB/RKR, dated May 14, 1992, provided a response to concerns stated. in an NRC letter, Zimmerman to Conway,,

dated April 7, 1992. Concern No. 2 indicated that, "MSSV test pr'ocedures were not being followed in that the setpoints of some valves were changed following the initial test instead of the third test as required by the procedure."

The APS response to this concern indicated that test procedure, 73ST-9ZZ18, Main Steam PSV Set Pressure Verification, permitted the test director to deviate from the requirement to perform two tests prior to setpoint adjustment if he felt that the additional testing would not provide relevant data for purposes of performing a setpoint adjustment.

The response went on to indicate that a note in the procedure stated that, 'The Test Director shall determine when to make adjustments."

The NRC reviewed the APS response to Concern No. 2 and reviewed test procedure 73ST-9ZZ19, Revision No. 4, PCN No. 3. We observed'that the note following procedure step 8.1.13 indicated that the test director could determine when to make adjustments, but a similar note following step 8.2.10 did not.indicate that the test director could determine when to make'adjustments. We concluded that the APS response to Concern No. 2 did not appear to take into account the difference in the procedure notes.

On October 9, 1991, MSSV testing was performed using procedure section 8.2, the Trevitest Method., A review of the test data indicated that valve SGEPSV574 had an acceptable lift setpoint for two tests but failed the third test. The data indicated the valve was adjusted after the third test, and the surveillance test log indicated that, "... contrary to note following step 8.2.10, valve will be adjusted 1.5 flat cw due to the decreasing trend."

NRC REQUEST APS is requested to provide additional information with regard to Concern No. 2 since, the initial APS response did not appear to take in account the difference between the notes in procedure sections 8.1 and 8.2. APS is requested to review the testing of SGEPSV574 on October 9, 1991, determine if procedure 73ST-9ZZ1 8 was followed, and provide the results of the determination. In addition, APS is requested to provide an assessment of the significance of adjusting valve SGEPSV574'fter one test failure.

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APS RESPONSE 1

The notes in procedure 73ST-9ZZ1 8 for steps 8.1.13 and 8.2.10 were not identical in that the note for 8.2.10 did not include the statement that 'The Test Director shall determine when to'make adj'ustments." Section 6.2, "Personnel Responsibilities," step 6.2.1 states that "A Responsible Engineering Evaluation Representative shall be the Test Leader and responsible for the following: 6.2.1.2 Directing test personnel," and "6.2.1.9 Determining what adjustments are to be made on valves found out of tolerance." Therefore, even

-though the notes are not the same, the procedure states that the Test Director/Leader is responsible for "Directing test personnel" and "Determining what adjustments are to be made on valves found out of tolerance."

The note in procedure 73ST-9ZZ18 for step 8.2.10 (i.e., step applicable to the testing

• being performed) stated that "In the event of an initial test failure, DO NOT make any adjustments to valve setpoint. After a'inimum 15 minute wait, the test may be reperformed. If results are still unacceptable, adjustment of setpoint is necessary (after 2 or 3 successive out-of-tolerance lifts), Section 8.3 steps shall be performed and verified in Appendix C, page 1 of 2." Section 8.3 provides instructions for set pressure adjustment. The note provides additional guidance for an initial test failure.

Subsequently, APS recognized that there could be a mis'understanding of the purpose of the note, and the notes in procedure 73ST-9ZZ18 for steps 8.1.13 and 8.2.10 were revised (effective January 15, 1992). The note in the test instructions section of the procedure was changed to state, "In the event of a failure of the initial (as-found) test, no adjustments should be made to the valve setpoint. After a minimum 10 minute wait, the test may be reperformed. If results are still unacceptable, adjustment of the setpoint may be necessary. Otherwise, the test director shall determine when to make adjustments."

As stated in our initial submittal, APS has reviewed the records of past performan'ce of the Main Steam Safety Valves (MSSV) test procedures and found that at least two tests

, were performed prior to setpoint adjustment. In the case of MSSV SGEPSV574, the setpoint was adjusted after the third test. The note in the procedure provided direction for an initial (as-found) test failure. If the initial test is satisfactory, then the valve may or may not be adjusted based on the Test Director's direction. Therefore, even though it was the first failure (on the third test), the Test Director was responsible for determining when setpoint adjustment was to be performed. Therefore, the comment referencing the note in step 8.2.10 was not required for setpoint adjustment to proceed.

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On October 17, 1991, MSSV SGEPSV574 was reset after three tests. The setpoint for MSSV SGEPSV574 is 1315 pound per square inch gauge (psig) +1% (allowed range of .

1302 psig to 1328 psig). MSSV SGEPSV574 lifted at the following pressures:

Test 1 1312.6 psig Test 2 1303.5 psig.

Test 3 1298.4 psig Test 4 1303.5 psig Test 5 1309.5 psig Test 6 1307.5- psig APS considers that it was appropriate to adjust MSSV SGEPSV574 after the third test.

The acceptance criteria in the procedure requires three consecutive lifts within the allowed range and the third test resulted in a failure prior to completing three consecutive lifts.

The lift pressure for Test 3 was below the minimum allowed pressur'e of 1302 psig and the lift pressure was trending down for the first three tests. This is not uncommon when an MSSV undergoes consecutive tests. Since the lift pressure was trending down and Test 3 was below the allowed range, the Test Director correctly determined that the valve should be adjusted prior to continuing further testing. Following the adjustment, the next three consecutive tests (Tests 4 through 6) were within the allowed range and required no further adjustment or testing.

Based on the discussion above, APS considers that the procedure was followed.

Therefore, adjusting the valve SGEPSV574 after the one failure on the third test was appropriate and is not significant since the failure was on the third test and the lift pressure was trending down.

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