ML20128B629
| ML20128B629 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 04/12/1985 |
| From: | Tucker H DUKE POWER CO. |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| SD-414-85-03, SD-414-85-3, NUDOCS 8505240632 | |
| Download: ML20128B629 (3) | |
Text
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e at s Duxe Powna Gownwxy P.O.mox(MH89 CHAussrrE, N,0. 3334g gi. 37 3J bN April 12, 1985 Dr. J. Nelson Grace, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 RE: Catawba Nuclear Station, Unit 2 Docket Nos. 50-414 Significant Deficiency No. 414/85-03 Dear Dr. Graces Pursuant to 10CFR 50.55(e), please find attached Significant Deficiency Report No. 414/85-03.
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Very truly yours.
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Hal B. Tucker LTP/mjf Attachment cc: Director Mr. Robert Guild, Esq.
Office of Inspection and Enforcement Attorney-at-Law U. S. Nuclear Regulatory Commission P. O. Box 12097 Washington, D. C. 20555 Charleston, South Carolina 29412 NRC Resident Inspector Mr. Jesse L. Riley Catawba Nuclear Station Carolina Environmental Study Group Palmetto Alliance 854 llenley Place 2135 Devine Street Charlotte, North Carolina Columbia, South Carolina 29205 28207 INPO Records Center Suite 1500 1100 circle 75 Parkway Atlanta, Georgia 30339 Z a7 m
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CATAWBA NUCLFAR STATION REPORT NUMBER:
SD 414/85-03 REPORT DATE:
April 12, 1985 FACILITY: CATAWBA NUCLEAR STATION UNIT 2 IDENTIFICATION OF DEFICIENCY:
Certain portions of piping systems were not protected from the effects of certain postulated LOCA pipe ruptures.
This had an effect on containment isolation provisions for two piping penetrations.
INITIAL REPORT:
On 3/15/85 Virgil Brownlee (NRC, Region 2) was informed by T.L.
Utterback and R.C.
Gamber (Both Duke Power Co., 422 South Church St., Charlotte, N.C. 28242)gvia telephone.
l ACTIVITY:
l This deficiency pertains to use of incorrect information in determining how containment isolation requirements would be met.
l DESCRIPTION OF DEFICIENCY:
The valves associated with several Component Cooling Water System (KC) containment penetrations were excluded from Type C testing requirements based, in part, on assurance of piping integrity inside containment following a LOCA.
Catawba FSAR Table 6.2.3-1 identifies the associated piping as being protected from effects of pipe whip, missiles and jet forces resulting from a LOCA. During an interaction review it was discovered that certain postulated LOCA breaks could potentially damage sone of the KC piping associated with two of the penetrations.
ANALYS!$ OF SAFETY IMPLICATIONS:
As a result of this deficiency it is possibte that following certain postulated LOCA pip 6
- breaks, post-accident containment atmosphere could enter KC system piping.
There are two containment penetrations and a total of five valves associated with this piping.
The valves were initially intended to serve as containment isolation valves.
Three of them are electric motor operated gate valves which receive a closure signal for containment isolation and are powered from safety sources.
These valves are connected with a seal water system which prevents containment atmosphere leakage when the valve closes in response to a containment isolation signal.
The remaining two valves are check valves.
With no valve or valve seal water system failure, containment isolation would be assured.
Assuming a specific break which damaged a portion of the KC piping and a failure of one of the gate valves outside containment it would be possible that containment atmoshpere could leak through a check valve and into the system piping in the Auxiliary Building.
The amount of leakage cannot be ascertained to be within acceptable limits.
... o CORRECTIVE ACTIONS:
The two check valves will be added to the list of valves which will be Type C tested.
Such testing in combination with the existing gate valves receiving a sealing fluid will assure acceptable containment isolation.
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