ML17305A694

Safety Evaluation Accepting Util Submittals on Summary of Piping Verification Test Program

ML17305A694
Person / Time
Site:	Palo Verde
Issue date:	04/17/1990
From:	Office of Nuclear Reactor Regulation
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ML17305A693	List: ML17305A692 ML17305A694
References
NUDOCS 9004230587
Download: ML17305A694 (6)

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UNITED STATES t NUC LEAR R EG ULATORY COMMISS ION WASHINGTON, D. C. 20555 OFFICE OF NUCLEAR REACTOR REGULATION SAFETY EVALUATION RELATED TO PIPING VERIFICATION TEST

SUMMARY

PALO VERDE NUCLEAR GENERATING STATION UNIT 1 INTRODUCTION License Condition 2.c(9) of NPF-41 requires that Arizona Public Service Company (APS) submit a

summary of piping vibration test results which demon-strate that the vibration of piping systems is within acceptable limits, within three months following completion of the piping vibration test program performed during initial startup.

In response to the license condition, and to a staff request for additional'nformation, APS provided its response in References 1

through 3.

DISCUSSION AND EVALUATION Reference 1 provided a report which summarized the results of the piping veri-fication test program.

In Section 2.7.1.1 of the report, the description of the tests indicated that the acceptability of the experienced vibration was determined by visual inspection and supplemented by vibrometer readings.

Following staff review of this report,, APS:was requested to provide a detailed description of the procedure which was used to verify that the stress values did not exceed one-half of the alternating stress intensity at 10 stress

cycles, as defined by the fatigue curves of Section III of the ASME BKPV Code.

This irformation was provided by Reference 3.

I The vibration test program consisted of obtaining vibration ve'locity measure-ments at selected locations and comparing them to an allowable screening velocity criterion.

This velocity criterion was determined based on ANSI/ASME OM-3-1982 (Reference 4).

Whenever the screening criterion was exceeded additional measurements were taken, including displacements, which were used as input to calculate the maximum stresses due to these displacements.

6These stresses were then compared to one-half of the alternating stress at 10 cycles.

For those cases where the allowable screening criterion was exceeded, no instances were found where the stresses exceeded one-half of the alternating stress.

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CONCLUSION Based on our review, we find both the test results and the screening velocity criterion acceptable, and as such, License Condition 2.c(9) is fully satisfied.

We recomnend, however, that in future piping vibration tests the screening.

velocity criterion be based on OHa-1988, Part 3 (Reference 5

principal, Contributor:

M. Har tzman Dated:

April 17, 1990

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REFERENCES 1.

Letter of April 18, 1986, from E.E.

Van Brunt, Jr.,

ANPP, to Document Control'Desk,

NRC, "PVNGS Unit 1'Piping Verification Test Summary" 2.

Letter of June 24, 1987, from J.G.

Haynes, ANPP, to Document Control

Desk, NRC, "PVNGS Unit 1 Piping Verification. Test 'Summary

'Supplement"'.

Letter of October 29, 1987, from J.G.

Haynes, ANPP, to Document, Control

Desk, NRC 4.

ANSI/ASME OM3-1982, "Requirements for Preoperational and Initial Start-up Vibration Testing of Nuclear Power Plant Systems" 5.

ASME/ANSI OMa-1988, "Operation and Maintenance of Nuclear Power Plants,"

Part 3..

Issued February 15, 1989

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