ML20092H872
| ML20092H872 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 06/22/1984 |
| From: | TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | Atomic Safety and Licensing Board Panel |
| Shared Package | |
| ML20092H838 | List: |
| References | |
| NUDOCS 8406260299 | |
| Download: ML20092H872 (3) | |
Text
s UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of
)
)
TEXAS UTILITIES ELECTRIC
)
Docket Nos. 50-445 and COMPANY, --et al.
)
50-446
)
(Comanche Peak Steam Electric
)
(Application for i
Station, Units 1 and 2)
)
Operating Licenses)
L APPLICANTS' STATEMENT OF MATERIAL FACTS AS TO WHICH THERE IS NO GENUINE ISSUE i
1.
In late 1981 Applicants identified four floor-to-ceiling supports designed by PSE without slip joints as being inconsis-tent with PSE guidelines.
The PSE guidelines state that such t
large-framed supports should have slip-joints, the purpose being to negate the need to analyze differential displacements of the
' supports between floor and ceiling or between walls.
Affidavit at p. 3.
2.
The four supports were conservatively designed such that the floor-to-coiling columns could simply be cut off and the support would still be adequate.
Id. at p. 4.
3.
To demonstrate the adequacy of the initial designs, using the computer code STRUDL, one of the four identical supports was analyzed using conservative assumptions and the resulting stresses in the support were all below allowables.
Indeed, the l
actual differential seismic displacement was calculated to be l
B406260299 840622 PDR ADOCK 05000445 g
PDR m
_2_
.006 inches; a limited displacement of this magnitude would, as a practical reality, not be a concern for these supports.
Id. at pp. 4-5.
4.
Applicants have reviewed all Unit 1 and common safety related piping supports and determined that there are an 26 supports spanning from wall-to-wall or floor-to-ceiling.
Of these 26 supports, seven have slip-joints, four have small spans and negligible movements and are not considered large-framed supports, and the remaining 15 have been evaluated and adequately consider the potential for differential seismic displacement.
Id. pp. at 5-6.
5.
None of these remaining 15 supports were designed by PSE, and all were designed prior to the time that the PSE guideline was made applicable to the other design organizations.
Id. at p.
6.
6.
The PSE guideline regarding floor-to-ceiling and wall-to-wall supports is not a code or procedural requirement, but rather guidance for the designer.
Id. at p.
6.
l 7.
The failure to follow the PSE guideline for these four i
supports did not require the generation of any QC non-conformance i
documentation.
If the supports had not been adequately designed, I
in the first instance, corrective action would have been required.
Id. at p. 7.
8.
Because there was a design change of the four supports, the QA program required generation of appropriate design change docu-mentation.
Id. at p.
7.
e-.
. 9.
The seismic deflection that could occur on wall-to-slab (ceiling or floor) supports consists of vertical deflection of the slab and horizontal deflection of the wall.
In that such supports are near the juncture of the slab and wall, the actual deflection realized at the support would be minimal and less than the maximum deflection realized toward the middle of the wall or slab.
Id. at p.
8.
10.
To determine if differential seismic deflection appeared to be a problem with wall-to-slab supports, Applicants analyzed three representative supports using a computer code, STRUDL.
The differential seismic displacement calculated ranged from.00035 inches to.0045 inches, which, as a practical reality, would not be a concern to any such supports.
In any event, the results of the computer analyses reflects that stresses for all members are within allowables.
Id. at pp.
8-9.
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