ML19345H379
| ML19345H379 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/15/1981 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8105200223 | |
| Download: ML19345H379 (3) | |
Text
l e
< li 0
j fA
'fh E3E 40 6 3
^
- f (412) 4w400o Pdtsbutgh, Pa.
NY T51981
~
United States Nuclear Regulatory Commission ggj D Region I g-631 Park Avenue King of Prussia, PA 19405
p
\\h ATN NTION:
Mr. Boyce H. Grier, Director
SUBJECT:
Beaver Valley Power Station - Unit No. 2
-l in'2 Docket No. 50-412 s
Possible Discrepancies Between Design Calculations and Drawings Released for Construction Significant Deficiency Report No. 81-02 Gentlemen:
Enclosed is the " Initial Interim Report" on the above subject.
If you have any questions concerning this report, we are available to meet with Nuclear Regulatory Commission personnel at their convenience.
Duquesne Light Company Wi t-W r./)f y By
{!
E.J/Woolever Vice President Enclosure "ect Mr. V. Stello, Director (15)
Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 moseoc @
s.
Ah
.p INITIAL INTERIM REPORT ON CONTROL ROOM EXTENSION Bt.
Beaver Valley Fower Station - Unit No. 2 1.0
SUMMARY
-i During a review of the structural design calculations for the Control Room Extension for Sisnificant Deficiency Report No. 80-07,
" Seismic Calculations for Cr.egory I Structures",
potential significant deficiencies were found to exist in certain reinforced concrete supporting members when all design load conditions are l
considered.
2.0 IMMEDIATE ACTION TAKEN Upon discovery of the potential significant deficiencies, a thorough.
investigation was started to review the calculations and drawings for this structure and is presently underway.
Construction of the structural work for this structure is nearly complete whilt tBe mechanical and electrical work 19 in the early stages.
No further major activity is scheduled for this structure until September, 1981.
Since this problem was construed to be a possible reportable signif-icant deficiency pursuant to 10CFR50.55(e) (1) (ii), the U. S.
Nuclear Regulatory Commission (NRC) was notified orally on April 16, 1981.
3.0 DEFICIENCY The Control Room Extension is the Control Room for BVPS-2 and is located adjacent to the Control Room for BVPS-1.
The Control Room Extension is separated from the BVPS-1 Control Room by a 4 in shake space. The Control Room Extension structure is a reinforced concrete structure with 4 ft-6 in thick mat located at l
elevation 707 ft-6 in.
The walls and roof are constructed of 2 f t-l 0 in thick concrete. The structure has two intermediate floors, one main operating room floor at elevation 735 f t-6 in and another cable spreading area floor at elevation 725 f t-6 in.
The floors are supported by interior beams, which are' framed in to exterior walls and interior columns.
The structure was designed in the period 1972-73 and constructed in the period 1973-74.
The initial review of the design indicates that ?n some cases the calculations and drawings appear to specify less reinforcing steel than is required to meet the ACI-318 stress allowables.
In addition, for certain structural members, discrepancies exist between the amount of reinforcing steel specified by the calculations and that j
specified on the' drawings.
l m
a---- E -
.-*.m m-.-
-2
.a 4.0 ANALYSIS OF SAFETY IMPLICATIONS Upon review of the design calculations, it appears that certain structural members at elevation 751 f t-8 in, elevation 735 f t-6 in, and elevation 725 f t-6 in could be stressed beyond SAR/ACI Code allow..bles for certain loading combinations.
It is not readily apparent, however, that such stress levels would lead to failure of the structural members. However, an extensive reevaluation is necessary and has been initiated.
5.0 CORRECTIVE ACTION TO REMEDY DEFICIENCIES All calculations for the structure are being reviewed to account for all applicable loading conditions in accordance with the PSAR. The structure will be reanalyzed and modifications made, as necessary, to meet all applicable loading conditions.
6.0 FINAL REPORT The final report will be submitted by August 31, 1981 at the completion of the reanalysis and determination of any required modifications.
94 4
-m.
m -
m m
m
-