ML20032A325
| ML20032A325 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 10/21/1981 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8110290418 | |
| Download: ML20032A325 (3) | |
Text
_ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _
TENNESSEE VALLEY AUTHORITY [JSNRO REGION 3 ATL ANTA. GEORGIA CHATTANOOGA. TENNESSEE 37401 400 Chestnut Street 'Ibwer II 81 OCT 23 - A B : 37 October 21, 1981-BLRD-50-438/81-53 BLRD-50-439/81-55 C
Mr. James P. O'Reilly, Director b
Office of Inspection and Enforcement U.S. Nuclear Regulatory Cannission
!,, 0g]<3 8 190 Region II - Suite 3100 E,
,,, w-n * ' M' #
101 Marietta Street
,m l
Atlanta, Georgia 30303 4
y.
//,
//
t
Dear Mr. O'Reilly:
O j i.e t l
BRrmtNfE PUCLFAR PLANT UNITS 1 AND 2 - FIREP100 PING MATERIAL APPLIED
'10 CONDUIT - BLRD-50-438/81-53, BLRD-50-439/81 FINAL REPOIH' he subject deficiency was initially reported to NIC-OIE Inspector R. V. Crlenjak on August 4,1981 in accordance with 10 CPR 50.55(e) as NCR 1528. mis was followed by our first interim report dated September 3, 1981. Enclosed is our final report.
If you have any questions concerning this matter, please get in touch'with R. H. Shell at ETS 857-2581.
4 i
Very truly yours, i
TD MESSEE VALLEY AUIHORITY M6
. gyL7 f
p L.M.Mi:Lis, Manager l
NuclearRegulationandMafety Enclosure 4
cc: Mr. Victor Stello, Jr., Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Crmmission Washington, DC 20555
_f6Y s
ih
$E0 228:4e gggggg O
PM An Equal opportunity Employer 1
1
9 BMPFTNTE NUCLEAR PLANT UNITS 1 AND 2 FIREPROOFING MATERIAL APPLIED 'IO CONDUIT 10 CFR 50.55(e)
BLRD-50-438/81-53, BLRD-50-439/81-55..
FINAL REPORT Description of Deficiency In Bellefonte Nuclear Plant's cable spreading room, exposed surfaces of steel require application of a fireproof coating. %ere are four
, voltage-level circuits which are routed into this roan. In order from lowest to highest voltage these are identified as V1, V2, V3, and V4 circuits. Some of these circuits are housed inside steel conduit.
There are cases where conduits were installed before the design a
requirement (Design Information Bequest DIR-030) to coat the exposed steel was implemented.
Usually horizontal runs of conduit cross perpendicularly to and are attached to the horizontal steel beams.
In other cases, the conduits penetrate the floor barrier. Fireproof coating was applied to conduits in 1-foot segments at these locations which generally occurred at nultiple locations.'
Ibever, before the fireproof coating application, it was determined that conduits containing voltage level V1, V2, and V3 circuits and their conduit supports could be coated with the appropriate thickness of fireproofing material. We V1, V2, and V3 voltage levels are used for instrumentation and control level circuits. % ese circuits are of low energy application and not subject to heat buildup.
Conservatively, it was decided that conduits containing power cables '
(V4 circuits) should not be coated since the coating may cause an overheating problem in the installed cables. Inadvertently, some conduits containing voltage level V4 circuits were partially coated with Pyrocrete 241, a fireproofing material.
Safety Implications Originally, there was some concern that the limited application of the subject coating to V4 level circuits could result in overheating those circuits. Overheating of those circuits would result in increased voltage losses and possibly loss of the circuit altogether. As stated below, TVA has determined that no implication to safety exists as a result of this condition because the heat buildup within the cable is not significant.
Corrective Action TVA has evaluated the ampacities of power cables installed in V4 level conduits where the fireproof coating was inadvertently applied. We heat transfer properties of Pyrocrete coating are conparable to those of concrete in that they allow heat. dissipation. We full load current of the involved circuits and the thermal conductivity of the Pyrocrete coating on conduits were evaluated for overheating of cables. Conductor heating of these cables, because of liJnited costing applied to conduits, is insignificant.
i
.f
~
1
. d' DIR-030 is being revised to allow limited Pyrocrete coating of conduits containing power. cables. WA sizes cables at-all naclear plants using the same design standards. %erefore, conductor heating of power cables, because of limited coating of PyrocreteL applied.to conduits at other WA nuclear plants, is also considered. insignificant.
O I
G
=,
t T
i e
e k
'