ML20215N678
| ML20215N678 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 10/27/1986 |
| From: | Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| ANPP-38862-JGH, IEB-85-003, IEB-85-3, NUDOCS 8611070153 | |
| Download: ML20215N678 (3) | |
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.h Arizona Nuclear Power Project ip W6 P.o. BOX $2034 e PHOENIX, ARIZONA 85072-2034 bl O
October 27, 1986 Q.
~g U. S. Nuclear Regulatory Commission
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Region V 1450 Maria Lane, Suite 210 Walnut Creek, CA 94596-5368 Attention: Mr. Dennis F. Kirsch, Director Division of Reactor Safety and Projects
Subject:
NRC IE Bulletin 85-03:
Motor-Operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Fettings N
File: 86-055-026 References (A) Letter from ANPP to U.S.
(
Subject:
Sahe; ANPP-37192-EEVB/JBK/98.05; dated June 30, 1986).
(B) Letter to ANPP from U.S.
NRC
(
Subject:
Same; dated Septe.nbe r 17, 1986).
Dear Mr. Kirsch:
Reference (A) contained ANPP's response to Item e in the subject bulletin.
Reference (B) that was received by ANPP on September 23, 1986, requested further clarification for two specific areas within ANPP's response _ to f the
/
bulletin.
Attached please find the responses to the ' two specific areas requested.
However, your inferences that ANPP has paraphrased the Bulletin's requirements in our original response are inappropriate and we will provide substantiation if required.
/
If you necd additional information or if you have any questions, do not 4
s hesitate to call.
s.
Very truly yours, s
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s J. G. Ha Vice President Nuclear Production JGil/JBK/ dim Attachments cc O. M. DeMichele (all w/a)
E. E. Van Brunt, Jr.
R. P. Zimmerman E. A. Licitra J. B. Martin A. C. Gehr U. S. Nuclear Regulatory Commission (Original)
Document Control Desk Washington, D.C. 20555 i
8611070153 861027 11 l
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ATTACHMENT A NRC QUESTION (1)
How were the values for the Delta P of the valves listed in Attachment B
-derived?
(The use of purchase documents for this purpose would not. be sufficient.
These valuec must be based on the design requirements of each valve).
l ANPP RESPONSE The Delta P values for each valve listed in Attachment B are. derived using the
' design basis events documented in the ' PVNGS FSAR/CESSAR, and the normal and emergency operating procedures.
Particular derivations and assumptions are documented in calculations for the AFW system and HPSI system.
For. the AFW system, the maximum differential pressure for each valve is determined using the most severe design basis event (i.e.,
the design basis event which imposes maximum differential pressure. at the valve) coupled with sufficient conservatism (e.g., frictionless flow).
For the HPSI system, ths maximum differential pressure is also determined using' the most severe design basis event coupled with sufficient conservatism.
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NRC QUESTIONs-i*
(2)
How will you determine if the valves are operable where testing with the
. maximum expected Delta P cannot be practicably performed?
Also, please elaborate concerning how Delta P testing will be accomplished.
s ANPP RESPONSE
\\
ANPP currendly utilizes differential pressure testing and MOVATS testing for.
the determination of valve operability, and is investigating the ' applicability of these techniques for determining valve operability at pressures that are not within the test Delta P range.
The valve test methodologies under review are:
'\\3 1.
Differential pressure test at or below maximum Delta P to demonstrate operability.
If the test is performed below maximum Delta P for a particular valve, the justification for the operability at maximum' Delta P will be accomplished from a conservative extrapolation from the lower DeltaPdqtatothehigherDeltaPdata.
2.
Motor Operated Valve Analysis and Test System (MOVATSTM) incorporated MOV Performance and Monitoring Program utilizes a signature analysis method to measure the general mechanical. condition and electrical configuration of a particular motor operated' valve.
The MOVATS device allows valve testing at below maximum Ialta P,
and for those valves s
where sufficient information is available, valve operability at maximum Delta P can be, determined by extrapolation from the below maximum Delta P data to the higher Delta P data.
Moreover, the M0 VATS device is presently utilized at PVNGS as a diagnostic tool-for investigating motor operated valve problems.
Therefore, when a stroke test cannot be performed at maximum differential pressure or flow rafe, the valve's operability will be verified using the methodologies under review or an adequate siternative method.
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