ML20083C853
| ML20083C853 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 12/19/1983 |
| From: | Dixon O SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8312270064 | |
| Download: ML20083C853 (3) | |
Text
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SOUTH CAROLINA ELECTRIC & GAS COMPANY POST OFFICE 764 cotuuoiA. soum CAROLINA 29218
- o. W. DixON. JR.
v Ca p..Sio."'
December 19, 1983 NUCLEAR opens TiONS Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 Tendon Surveillance Technical Specification Changes
Dear Mr. Denton:
In-a letter dated July 22, 1983, South Carolina Electric and Gas Company (SCE&G) requested a change to the Virgil C.
Summer Nuclear Station Technical Specifications _for Containment Structural Integrity,_ Table, 4.6-la, 4.6-lb, and 4.6-2.
The NRC
' Staff initiated their review of the proposed Technical Specification change and requested that SCE&G provide additional information to complete the review.
The information requested by the NRC Staff is addressed as follows:
1.
A description and explanation of the nature of the error in the calculations which caused the Base Value for the hoop tendons listed in Tables 4.6-la and 4.6-lb to be too high.
Response
The Base Values of tendon forces for all hoop tendons have been recalculated to correct an error in the original 1981 c-alculations which established the present values.
The error existed in recording a value of (0.2013) for the Ultimate Specific Creep Constant (USCR).
In actuality, the USCR should have been (0.2394) which is approximately 19%
greater than the incorrect value of (0.2013).
The impact of the error resulted in predicted tendon forces 0.3% to 0.5%
greater than necessary.
8312270064 831219
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Mr.' Harold R.' Denton,fDirector Tendon Surveillance Technical Specification Changes December 19,.1983
- Page $2-2..
An explanation of why the values proposed are more conservative than those existing in the present Technical
-Specification.
. Response:
The Base. Values existing in the present Technical Specification are more conservative.than the proposed values but the proposed values are correct.-The error in the calculations of hoop tendon force Base Values was in the conservative direction.
Even though the error created the more conservative Base Values existing presently in the Technical Specification,-these values were higher than they actually should be.
3.
Justification that the previous surveillance results will be compatible -with and acceptable to the revised values.
t
Response
The previous surveillance results will be compatible and acceptable because.the error resulted in higher Base Values,
[
-1.e.,
more conservative values.
Therefore, SCE&G was actually. performing the surveillance testing to a-more stringent individual tendon acceptance criterion, since this criterion was proportional to Base value.
i 4.-
Justification that the values proposed will not reduce the p
margin of safety of the containment.
l
Response
The: margin of safety.will not be reduced by the proposed
(-
Base Values because the proposed values are the the correct
[
Base Values for the hoop. tendon forces.
The margin of' safety for the' containment is considered in the proposed
' Base Values..
L I
L h
E t
..~ -,
Mr. Harold R. Denton, Director Tendon Surveillance Technical Specification Changes December 19, 1983 Page #3 If you require further information, please advise us.
Very trul
- ours, k
&f s
O. W.
xon, Jr.
JKT:WRM:OWD/fjc cc:
V.
C.
Summer T.
C.
Nichols, Jr./O. W.
Dixon, Jr.
E. H.
Crews, Jr.
E.
C. Roberts W. A. Williams, Jr.
D. A.
Nauman J.
P. O'Reilly Group Managers O.
S. Bradham C. A.
Price C. L. Ligon (NSRC)
G. J. Braddick D. J.
Richards NRC Resident Inspector J.
B.
Knotts, Jr.
.NPCF File I