TXX-7126, Final Deficiency Rept CP-87-70 Re Prebend Pipe Wall Thickness.Initially Reported on 870824.Preformed Pipe Bends Ultrasonically Tested.Item Not Reportable Per 10CFR50.55(e)
| ML20238D812 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 12/28/1987 |
| From: | Counsil W, John Marshall TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| CP-87-70, TXX-7126, NUDOCS 8801040448 | |
| Download: ML20238D812 (2) | |
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nlELECTRIC December 28, 1987 William G. Counsil Executist %ce President U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C.
20555
SUBJECT:
COMANCilE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50-445 AND 50-446
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PRE-BEND PIPE WALL THICKNESS SDAR: CP-87-70 (FINAL REPORT)
Gentlemen:
On August 24, 1987, we verbally notified your Mr. H. S. Phillips of a potentially reportable item involving possible violation of pre-bend pipe wall thickness due to inadequate OC inspection procedures. Our last report was logged TXX-7088, dated December 22, 1987. After further evaluation we have determined that this item is not reportable pursuant to 10CFR50.55(e).
This item was identified by third party review, as documented in Corrective Action Request (CAR) 87-41, of bender qualification results.
This review identified that wall thinning due to the bending process can be as high as 12.3*5.
However, procedure CP-CPM 6.9E " Pipe Fabrication and Installation,"
allows the use of piping with a pre-bend wall thickness as little as 6%
thicker than the manufacturer's minimum pre-bend pipe wall thickness.
This may have resulted in some instances of post-bend pipe wall thicknesses below the manufacturer's minimum requirements.
To date, approximately 208 pipe bends have been ultrasonically tested. All bends tested meet the manufacturer's minimum pipe wall thickness requirement.
There is no indication that either the bending process, nor the lack of post-bend inspections (resulting from the inadequate QC inspection procedures) resulted in any pipe wall thickness violations.
This provides the basis for our evaluation that this item is not reportable pursuant to 10CFR50.55(e).
To further assure that pipe wail thicknesses does not violate this criteria, all pipe bends preformed at CPSES will be inspected to confirm acceptable minimum post-bend wall thickne;s by walkdown and ultrasonic testing as required by CPE-SWEC-FVM-EE/ME/IC/CS-089 and 090 " Post Construction Hardware Validation (PCilV) Program Erigineering Walkdowns," as part of the Post Construction Hardware Validation (PCHV) Program.
Any pipe bends found to violate manufacturer's minimum pipe wall thickness requirements will be documented and dispositioned using CPSES nonconformance reporting procedures.
60 8801040448 871228 f
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TXX-7126 December 28, 1987 Page 2 c f 2 In order to prevent recurrence of this problem, 2323-MS-100 " Piping Erection Specification" and procedure CP-CPM-6.9E " Pipe Fabrication and Installation" have been revised to require recording of pre-bend pipe wall thickness on the Manufacturing Record Sheet and confirmation that manufacturer's minimum wall thickness be met after bending.
Walkdown and testing results will be available at the CPSES site following the completion of the Post Construction Hardware Validation (PCHV) Program for this activity, currently scheduled for March 1,1988.
Very truly yours,
((l, (. (ou a si (
W. G. Counsil O
By:
JJ S. Marshall Supervisor, Generic Licensing HAM /grr c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3) e