ML17303A565

Forwards Response to NRC Bulletin 87-001, Thinning of Pipe Walls in Nuclear Power Plants

ML17303A565
Person / Time
Site:	Palo Verde
Issue date:	09/11/1987
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
161-00501-JGH-J, 161-501-JGH-J, IEB-87-001, IEB-87-1, NUDOCS 8709230406
Download: ML17303A565 (18)

Text

DOCKET 05000528 05000529 05000530 REGULA Y INFORMATION DISTRIBUTIO 'STEM (RIDS)

ACCESSION NBR: 8709230406 DOC. DATE: 87/O'P/11 NOTARIZED:

YES FACIL:.STN-50-528 Palo Verde Nuclear Stations Unit ii Arizona Pub li STN-50-529 Palo Verde Nuclear Stations Unit 2. Arizona Publi STN-50-530 Palo Verde Nuclear Stations Unit 3i Arizona Pub li AUTH. NAME AUTHOR AFFILIATION HAYNES'. G.

Arizona Nuclear Poeer Prospect

< formerly Arizona Public Serv RECIP. NAME RECIPIENT AFFILIATION Document Control Branch

<Document Control Desk)

SUBJECT:

Foreards response to Bulletin 87-001'Thinning of Pipe Walls in Nuclear Power Plants.

DISTRIBUTION CODE:

IE11D COPIES RECEIVED: LTR ENCL SIZE:

TITLE: Bulletin Response (50 DKT)

NOTES: Standardized plant.

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LPDR NSIC COPIES LTTR ENCL 1

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TOT*L NUMBER OF COPIES REQUIRED:

LTTR 21 ENCL 20

Arizona Nuclear Power Project P.O. SOX 52034

~

PHOENIX, ARIZONA85072-2034 161-00501-JGH/JBK September 11, 1987 Docket Nos.

STN 50-528/529/530 U.

S. Nuclear Regulatory Commission Document Control Desk Washington, D.C.

20555

Subject:

NRC Bulletin No. 87-01:

Thinning of Pipe Walls in Nuclear Power Plants File:

87-055-026 The subject Bulletin was received by ANPP on July 13, 1987 and requested information concerning Palo Verde's piping erosion/corrosion monitoring program.

Attached please find ANPP's response to each Bulletin item.

If you have any question or require additional information, do not hesitate to call.

Very truly yours, J.. G.

Haynes Vice President Nuclear Production JGH/JBK/dim Attachment cc:

0.

M.

De Michele E.

E.

Van Brunt, Jr.

J.

B. Martin E. A. Licitra A.

C. Gehr J. Ball (a11 w/a) 870923040b 8709ib PDR ADOCK 05000528 9,

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STATE OF ARIZONA

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COUNTY OF MARICOPA)

I, Jerry G.

Haynes, represent that I am Vice President of Nuclear Production of Arizona Nuclear Power Project, that the foregoing document has been signed by me on behalf of Arizona Public Service Company with full authority to do so, that I have read such document and know its contents, and that to the best of my knowledge and belief, the statements made therein are true and correct.

fg-Jerry G.

aynes Sworn ro before me rhfs~l day of 0 Il

, 1987.

Notary Pu c

My Commission Expires:

'<y Co~~'s'.i<n F.:.pires Nov, 19. 1998

1

ATTACHMENT ANPP RESPONSES TO NRC BULLETIN NO. 87-01

NRC QUESTION Within 60 days from the receipt of this bulletin, licenses are requested to provide the following information concerning their programs for monitoring the wall thickness of pipes in condensate, feedwater,

steam, and connected high-energy piping systems, including all safety-related and non-safetymelated piping systems fabricated of carbon steel:

l.

Identify the codes or standards to which the piping was designed and fabricated.

ANPP RESPONSE In general, all applicable codes including ASME Sections I, III and VIII, ASTM, ANSI B16.5 and ANSI B31.1 were used for the design and fabrication of Palo Verde's piping systems.

Specific information for individual pipes is available in the PVNGS Design Criteria Manual and PVNGS Piping Material Classification List.

aV t

l l

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NRC QUESTION 2.

Describe the scope and extent of your programs for ensuring that pipe wall thicknesses are not reduced below the minimum allowable thickness.

Include in the description the criteria that you have established for:

a.

Selecting points at which to make thickness measurements.

b.

Determine how frequently to make thickness measurements.

c.

Selecting the methods used to make thickness measurements.

d.

Making replacement/repair decisions.

ANPP RESPONSE ANPP has developed pipe erosion monitoring guidelines which address point selection criteria, inspection frequency, inspection method and replacement/.

repair decisions.

Point selection criteria currently include review of piping drawings and actual plant installation while considering whether the component:

Is carbon steel pipe Contains less than 1X chrome,

.5X Molybdenum,

.3X Copper Is any flow restricting device Contains fluid temperatures greater than 250 degrees Fahrenheit Contains flow velocities greater than 14 feet per second Has fittings or flow restrictions within five pipe diameters Experiences changes in flow direction These criteria and individual pipe data are then used by the EPRI "CHEC" program to determine the relative erosion wear rate and minimum wall thickness.

Inspection frequency of the selected inspection points is expected to be each refueling outage.

Inspection method will utilize nondestructive examination or an equivalent method.

Results of each examination will be compared to the minimum allowable wall thickness to determine whether replacement/repair should be immediate or during the next outage.

NRC QUESTION 3.

For liquid-phase

systems, state specifically whether the following factors have been considered in establishing your criteria for selecting points at which to monitor piping thickness (Item 2a):

a.

Piping material (e.g.,

chromium content) b.

Piping configuration (e.g.,

fittings less than 10 pipe diameters apart) c.

pH of water in the system (e.g.,

pH less than 10) d.

System temperature (e.g.,

between 190 and 500'F) e.

Fluid bulk velocity (e.g., greater than 10 ft/s) f.

Oxygen content in the system (e.g.,

oxygen content less than 50 ppb)

ANPP RESPONSE Palo Verde's methodology for selecting erosion-corrosion monitoring inspection points utilizes the guidelines cited in the previous response and the EPRI "CHEC" computer program which addresses all of the listed factors.

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NRC QUESTION 4.

Chronologically list and summarize the results of all inspections that have been performed, which were specifically conducted for the purpose of identifying pipe wall thinning, whether or not pipe wall thinning was discovered, and any other inspections where pipe wall thinning.

was discovered even though that was not the purpose of that inspection.

a.

Briefly describe the inspection program and indicate whether it was specifically intended to measure wall thickness or whether wall thickness measurements were an incidental determination.

b.

Describe what piping was examined and how (e.g.,

describe the inspection instrument(s),

test

method, reference thickness, locations

examined, means for loading measurement point(s) in subsequent inspections).

c.

Report thickness measurement results and note those that were identified as unacceptable and why.

d.

Describe actions already taken or planned for piping that has been found to have a nonconforming wall thickness.

If you have performed a failure analysis, include the results of that analysis.

Indicate whether the actions involve repair or replacement, including any change of materials.

ANPP RESPONSE ANPP has not performed any inspections for specifically identifying pipe wall thinning.

Additionally, no other unrelated inspections have discovered pipe wall thinning.

fl

NRC QUESTION 5.

Describe any plans either for revising the present or for developing new or additional programs for monitoring pipe wall thickness.

ANPP RESPONSE ANPP has no plans for revising the present program or developing additional programs for monitoring pipe wall thickness until results from the initial inspections are reviewed.