ML20031C663
| ML20031C663 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 10/02/1981 |
| From: | Baxter T SHAW, PITTMAN, POTTS & TROWBRIDGE, UNION ELECTRIC CO. |
| To: | Atomic Safety and Licensing Board Panel |
| Shared Package | |
| ML20031C639 | List: |
| References | |
| NUDOCS 8110070436 | |
| Download: ML20031C663 (6) | |
Text
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Octobsr 2,1981 1
e UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD I
In the Matter of
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UNION ELECTRIC COMPANY
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Docket No. STN 50-483 OL
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(Callsway Plant, Unit 1)
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APPLICANT'S STATEMENT OF MATERIAL FACTS A3 TO WHICH THERE IS NO GENUINE ISSUE TO BE HEARD ON JOINT INTERVENORS' CONTENTION NO. I.D (CONCRETE COVER)
Pursuant to 10 C.F.R.
S 2.749 (a), Applicant states,
in support of its Motion for Summary Disposition of Joint Intervenors' Contention No. I.D (Concrete Cover) in this procaading, that there is no genuine issue to be heard with respect to the following material facts:
1.
Part I.D of Joint Intervenors' Contention No. 1 i
alleges that there exist many areas where concrete coverage of reinforcing bars in concrete walls and floors at the Cal-laway Plant does not adhere to requirements.
Two numbered examples are set forth, both of which address the exterior wall of the reactor building.
Amended and Supplemental Joint Petition to Intervene, March 6, 1981, at 9, 10.
2.
Concrete cover is the thickness of the concrete layer measured from the concrete surface to the nearest surface of the reinforcing steel (rrebar").
The concrete cover of interest in Joint Intervenors' Contention No. I.D is the i
'812 0 0's O YM
- thickness of the layer of concrete between the outside face of the reactor building wall and the outside edge of the rebar nearest to that face of the wall.
Affidavit of Subir K. Sen in Support of Applicant's Motion for Summary Disposition of Joint Intervenors' Cantention No. I.D (Concrete Cover)
("Sen Affidavit"), para. 5.
3.
Because it is not practical to build to theoretical design dimensions, certain amounts of tolerances are allowed, for example, in the fabrication of the rebars and in the erec-tion of the formwork rebars and other embedded items.
These tolerances are identified in the construction specifications j
and constitute limited deviations about a mean value used in the design.
Since any variation in the locations of rebar and/or formwork would affect the concrete cover, it is standard engineering practice to provide a similar tolerance band on 4
the specified concrete cover used in the design.
Consequently, as long as the concrete cover in actual construction is main-tained within the stipulated tolerance band, it is considered f
to have met the design requirements.
Sen Affidavit, para. 7.
4.
In 1974 Bechtel prepared a Topical Report, i
BC-TOP-5, which was approved by the NRC Staff for use on the SNUPPS project, including the Callaway Plant, and which provides, in part, the techniques and procedures used for the design of the prestressed concrete reactor building.
The SNUPPS Preliminary Safety Analysis Report references BC-TOP-5 for minimum and maximum concrete cover to be used t
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_3 in the design -- which are two inches and about ten inches, respectively, for the reactor building wall.
The PSAR states that the tolerance on the cover shall be as much as plus or minus 1.5 inches, but that the cover shall not be reduced by more than one-third the specified (i.e., design) cover.
Sen Affidavit, paras. 16, 17.
5.
On January 5,1978, the NRC Staff was conducting a special, announced investigation into anonymous allegations regard 3ag, among other things, improper concrete cover for reinforcement.
The NRC inspectors did not agree with Applicant's interpretation of minimum cover requirements, which would allow a reduction of the two-inch minimum by one-third.
The NRC personnel indicated that their interpretation of the require-ment was that the two-inch cover minimum cannot be further reduced.
Subsequently, the NRC Staff also indicated that P
they viewed the 10-inch maximum to be an absolute.
NRC repre-sentatives indicated that it would be acceptable if the cover requirements, as interpreted by the NRC Staff, were fully met in the area of the sixth lift, utilizing the fifth lift as a transition area.
Sen Affidavit, paras. 20-22.
6.
Union Electric Company agreed to comply with the NRC Staff's interpretation of the concrete cover require-ments starting at the sixth lift.
Design documents were revised to reflect this decision.
Sen Affidavit, para. 22.
7.
With two exceptions, all of the examples cited in Joint Intervenors' Contention No. I.D of violations of 1
. minimum concrete cover requirements involved instances where the cover was less than two inches but within the one-third tolerance applied by Applicant, and wh. h were later determined by the NRC Staff to be acceptable for those lifts in the reactor building wall.
NRC inspectors, who observed the pre-placement preparation for the fourth lift, identified two instances where the concrete cover was less than the minimum requirement as interpreted by Applicant.
These items were promptly corrected and reinspected by the NRC personnel.
Identification of such items by NRC inspectors does not necessarily indicate any failure of the constructor's quality control program, since such NRC inspections sometimes precede the constructor's inspection.
Affidavit of R. David Neal in Support of Applicant's Motion for Summary Disposition of Joint Intervenors ' Contention I.D (Concrete Cover) ("Neal Affidavit"), para. 3.
8.
With respect to maximum cover requirements below the sixth lift, there are only very local areas around two electrical penerrations where, due to the geometry of the blockout, field tolerances were utilized so that maximum cover requirement are exceeded.
Because strict adherence to the placing provision over local areas v.7re not intended and was not viewed to be technically required, Bechtel dispositioned a Daniel Non-Conformance Report on this matter "use as is."
The structural integr2 ty of the containment
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shell will not be compromised in any way where the maximum l
1 cover design limits were exceeded in these local areas.
Sen Affidavit, para. 24; Neal Affidavit, para.
4.
9.
Applicant and its contractors did not misunder-stand or ignore concrete cover requirements for the external wall of the Callaway Plant reactor building.
They were con-sistently interpreted and applied though the fourth lift.
Sen Affidavit, para. 25; Neal Affidavit, para. 5.
Applicant's interpretation of the ragtirements was technically correct and sound, and, with respect to tolerances for minimum cover, was consistent with the American Concrete Institute's st-ndard which is the most widely used code for concrete structures.
Sen Affidavit, paras. 18, 75.
The NRC Staff advanced a dif-ferent interpretation of the requirements, which are subject to more than one reasonable interpretation, and Applicant agreed to utilize the NRC Staff's interpretation beginning with the sixth lift.
Id., para. 25.
10.
Joint Intervenors have presented no evidence to support the proposition that the application of concrete cover requirements will affect the safe operation of tha callaway Plant.
Joint Intervenors Answers to Applicant's Interrogatory Nos. 1D-7 (First Set) and 1D-24 (Second Set).
11.
In fact, years of field experience in many different environments, exposure tests conducted in extremely aggressive environments, and the standard of the American Concrete Institute, demonstrate that the application of the concrete cover requirements below the sixth lift of the 1
l
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- Callaway Plant reactor building wall will not affect the inte.grity of the structure and is adequate for the concrete cover to perform its two functions -- corrosion protection for reinforceing steel and bond development between the steel and concrete.
Sen Affidavit, paras. 8-15, 18, 19, 23, 24.
Respectfully submitted, SHAW, PITTMAN, POTTS & TROWBRIDGE Thomas A.
Baxter Richard E. Galen Counsel for Applicant 1800 M Street, N.W.
Washington, D.C.
20036 (202) 822-1000 I
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