TXX-6461, Final Deficiency Rept CP-86-64 Re Internal Coatings for Unit 2 Diesel Fuel Oil Tanks.Initially Reported on 860904. Coatings Neither safety-related Nor Reportable Per 10CFR50.55(e)
| ML20214H962 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 05/22/1987 |
| From: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| CP-86-64, IEIN-87-004, IEIN-87-4, TXX-6461, NUDOCS 8705270560 | |
| Download: ML20214H962 (2) | |
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M Log # TXX-6461
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File # 10110 L
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Ref # 10CFR50.55(e) 1 1UELECTRIC
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May 22, 1987 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 INTERNAL C0ATINGS FOR UNIT 2 DIESEL FUEL OIL TANKS SDAR: CP-86-64 (FINAL REPORT)
Gentlemen:
On September 4,1986, we verbally notified your Mr. I. Barnes of a deficiency involving the internal protective coatings for the Unit 2 diesel fuel oil storage tanks. We have submitted interim reports, logged TXX-6013, TXX-6263, and TXX-6336, dated October 3, 1986, February 6, 1987, and March 23, 1987, respectively. Our evaluation is completed and our conclusion is, had the issue remained uncorrected it would not have affected the safe operation of the plant. This issue is not reportable under the provisions of 10CFR50.55(e).
Our investigation has determined that the original intent in invoking the requirements of Specification AS-31, " Protective Coatings," for the diesel fuel oil storage tanks was to ensure a high quality of workmanship through the specification's inspection and documentation requirements, not to classify the coating. However, once governed by the AS-31 specification for Safety Related containment coating, the tank coating became regarded (incorrectly) as Safety Related.
In 1985, when this specification was declassified and containment coating became Non-Safety, the impact of this change on the tank coating was not addressed. These events led to the "... unresolved issues involving the repair process for the internal coatings of the Safety Related tanks" referred to in our letter TXX-6013.
We have concluded that the coating inside the fuel oil storage tanks is not Safety Related. Our assessment considered coating degradation and potential blockage of the suction lines to the fuel oil transfer pumps.
Fluid flow rates in the immediate vicinity of the suction lines are too low (on the order of five feet per minute) to transport the large paint chips which would be required to block the end of the suction line.
Should blockage of one suction line occur however, the redundant transfer pump and its suction line may be used to continue fuel transfer while the initial line blockage is cleared.
In addition, the day tank holds three hours of fuel below the low level alarm setpoint. Technical Specifications require the contents of the storage tanks to be sampled every 92 days for moisture and sediment.
In the event that paint chips began to accumulate in the tank, the condition would be identified through these inspections and appropriate maintenance actions, as required by l
the Technical Specifications for CPSES, would be initiated.
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B705270560 870522 DR ADOCK 0500 6
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l TXX-6461 May 22, 1987 Page 2 of 2 We have additionally evaluated the cumulative effects of. corrosion to the diesel generator fuel oil storage tanks. Our evaluation determined that corrosion had been considered in the design of the fuel oil storage tanks.
The fuel oil tanks provide an additional wall thickness in excess of the one sixteenth inch (1/16") corrosion allowance for the 40 year design life.
We have completed our assessment of Nuclear Regulatory Commission Information Notice 87-04 impact on this issue and find it does not affect our evaluation.
We therefore conclude that neither the presence of failed coating particles or resulting corrosion could have adversely affected the safety of plant operation and the deficiency is not reportable per 10CFR50.55(e).
Records supporting this evaluation are available for your inspectors' review at the CPSES site.
Very truly yours M fars/,
W. G. Counsil RWH/gj c - Mr. R. D. Martin - Region IV CPSES Resident Inspector - 3 copies i
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