TXX-6607, Interim Deficiency Rept CP-87-18 Re Errors Identified During Review of Vendor Qualification Documentation for Component Cooling Water Hxs.Initially Reported on 870608.HX Loadings Evaluated.Next Rept Expected by 870911
| ML20236K736 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/03/1987 |
| From: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| CP-87-18, TXX-6607, NUDOCS 8708070236 | |
| Download: ML20236K736 (2) | |
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Log # TXX-6607 l
i F9 File # 10110 l
909.2 f
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Ref # 10CFR50.55(e) l 1UELECTRIC l
August 3, 1987 3.,
Executive Vks Presuknt U. S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.C.
20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50-445 AND 50-446 COMP 0NENT C0OLING WATER (CCW) L! EAT EXCHANGER SEISMIC QUALIFICATION SDAR:
CP-87-18 (INTERIM REPORT)
Gentlemen:
On June 8, 1987, we verbally notified your Mr. I. Barnes of a deficiency involving errors identified during a review of the vendor qualification documentation for the CCW heat exchangers that indicated the seismic and nozzle loading conditions exceed specification requirements and could be overstressed. This is an interim report of a potentially reportable item under the provisions of 10CFR 50.55(e).
Our initial evaluation of the subject heat exchangers showed stresses exceeding the allowables in both the heat exchanger shell and the supports.
We have also determined that the specification nozzle loadings contributed a significant portion of the total heat exchanger loading.
To reduce the l
conservatism in the initial evaluation, the heat exchangers were evaluated j
further using the as-built piping loadings.
Piping as-built nozzle loadings were obtained and were found to be l
significantly lower than the specification loadings.
The nozzle loads and the seismic inertia loads were applied to a finite element model (FEM) of the heat exchanger to obtain shell loadings, support loadings, and reaction forces.
Overall heat exchanger shell stresses, local shell stresses at nozzles, local shell stresses at supports, and support stresses have been analyzed.
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40a North Olive Street LB Si Dallas, Texas 75201 5
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August 3, 1987 i
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Preliminary results from this evaluation indicate that the Unit I heat exchangers meet ASME Boiler & Pressure Vessel code and FSAR stress limits.
Before the evaluation is finalized, the following items must be addressed:
1)
The first mode frequency of the heat exchanger was determined to be less than 33 Hz. The impact of the heat exchanger flexibility on the piping analyses must be determined.
2)
The heat exchanger anchorage loadings must be evaluated.
3)
The heat exchanger concrete pedestal supports must be evaluated to determine the pedestal natural frequencies.
If the pedestal fundamental frequency is found to be less than 33 Hz, further evaluation of the heat exchangers will be required.
4)
Unit 2 as-built nozzle loadings must be obtained before an evaluation can be performed on the Unit 2 heat exchanger.
5)
Piping mode shapes and frequencies for the piping connected to the CCW heat exchanger nozzles must be obtained to justify combining the four nozzle seismic loadings as performed in the evaluation.
i Our next report on this issue will be submitted no later than September 11, 1987.
Very truly yours, 7&
W. G. Counsil MCP/mgt c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3) 1
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