ML20038C762
| ML20038C762 | |
| Person / Time | |
|---|---|
| Site: | Satsop |
| Issue date: | 12/07/1981 |
| From: | Faulkenberry B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Leddick R WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8112140108 | |
| Download: ML20038C762 (2) | |
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N' s N DEC 7 1981 Docket No. 50-508 f ' ;w-C; Il 4'
.e Washington Public Power Supply System Q^6 P. O. Box 1223 Dg0
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Elma, Washington 98541 1g a
Attention: Mr. R. S. Leddick d
SE Program Director, WNP-3/5 y
4 Gentlemen:
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Subject:
Final Report of Potential 10 CFR 50.55(e) Concrete Placement AEW 019 and 21, 428.50 (your reference G03-81-2724)
Thank you for the subject report fowarded by your letter of November 11, 1981. Our preliminary review of this report indicates that certain additional information is necessary in order for us to complete our evaluation of the actions you have taken to cop ct the described deficiency.
Please provide this office, within 30 days of the receipt of this letter, the additional information as described below.
1.
Structural Intearity of the Repaired Wall Section B of the report states that "The extensive nature of unconsolidated concrete -- was judged detrimental under the most adverse design loading conditions-- ". The section then explains that standard repair methods were used and that the engineer's opinion is "-- that the wall has been restored to a condition such that the capability of the structure to function reliably and safely is unimpaired and that all original design criteria are mt."
While we have examined the records of your disposition of this wall, the basis for the Engineer's conclusion is not apparent. Questions which have arisen are:
a.
Is there a basis for concluding that the concrete in the placement is essentially homogeneous? That is, are the repairs bonded to the parent concrete without shrinkage cracks or other deleterious effects?
b.
Since the toided areas were identified by excavation (chipping; from the exposed surfaces is there a basis for
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concluding that all significant void areas have been identified?
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Certain void areas such as the side of the doorway between 417.5 and about 422.0 were so extensive as to constitute a full unplanned cold joint.
It is our experience that such unplanned angular joints often require additional reinforcenent in the form of dowels.
Since dowels were not added, what is the basis for concluding that the shear strength of the wall at such a location has been naintained?
d.
Is there any experimental data availcble which provio.s a basis for concluding that such a rc7 aired placenent :s structurally similar to a placenent wh'ch requires cosnetic repairs only. For instance does ACI or any other institution have some conparative load capability data?
2.
Repair of the Wall Section C.l. of the recort addresses " Corrective Actions Taken".
The disposition of various wall defects are described in this section and attached t'CR's.
We have the following questions fron our review of this section:
a.
Was each 'RP Plate' exanined by chipping or drilling to assure the ir+egrity of the anchorage?
b.
When epoxy or other greut was used to fill voided areas behind the plates, how was conplete filling of the voids assured?
3.
Corrective Action ;o Precluded Recetition Section C.2. addresses corrective action to prevent recurrence of sinilar problers. This section simply s'ates tha' certair, listed renedies "-- have been discussed with the toi, actor- ".
It is our position that listing the remedies discussed with a contractor does not neet 10 CFR 50.55(e)(3) which states, in part, that reports shall include a descriotion of "-- the corrective action taken, and sufficient infornation to Pernit analysis and evaluation of the deficiency and of the corrective action."
Please orovide infornation which defines the actions actually taken by the contractor to prevent recurrence.
Sincerely, C. H. Faul':enberry, Chief Reactor Construction Pro.iects Pranch
/LIDE'
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