ML19341A920
| ML19341A920 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 01/19/1981 |
| From: | Tedesco R Office of Nuclear Reactor Regulation |
| To: | Abel J COMMONWEALTH EDISON CO. |
| References | |
| IEB-80-11, NUDOCS 8101290339 | |
| Download: ML19341A920 (4) | |
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UNITED STATES f'.,,,
g NUCLEAR REGULATORY COMMISSION f
WASHINGTON. O. C 20555
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p 4AN 19 N sA Docket Nos.:
50-373 aX l Y and 50-374
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p;, u.s.,,,,,d,'jPoer Mr. J. S. Abel Ccamenwealth Edison Company cc%,
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Chicago, Illinois 60690 Q,
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Dear Mr. Abel:
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION ON CATEGORY I MASONRY WALL DESIGN OF LASALLE COUNTY STATION, UNIT N05. 1 & 2 As a result of reviewing your response dated July 8,1980 to our concerns relative to Category I masonry wall design at LaSalle, we find that we need additional infornation. The specific information required is provided in the Enclosure.
If you desire any discussion or clarification of the information requested, please contact A. Bournia, Licensing Project Manager, (301)492-7200.
Sincerely.
Robert L. Tedesco, Assistant Directne for Licensing Division of Licensing l
Enclosure:
Request For Additional Information ces w/ enclosures:
See next page l
Mr. J. S. Abel Director of Nuclear Licensing Connonwealth Edison Company Post Office Box 767 Chicago, Illinois 60690 cc: Philip P. Steptoe, Esq.
Suite 4200 One First National Plaza Chicago, Illinois 50603 Dean Hansell, Esquire Assistant Attorney General 188 West Randolph Street Suite 2315 Chicago, Illinois 60601 Mr. Roger Walker, Resident Inspector U. S. Nuclear Regulatory Commission Post Office Box 224 Marseilles, Illinois 61364 k
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Enclosure Request for Information on Masonry Wall LaSalle County Station, Unit Nos. 1 and 2 Docket Nos. 50-373/374 1.
Provide a copy of S&L specification J-2596.
2.
Discuss how the leads are transferred from walls to columns. " Discuss L
and substantiate the adequacy of the anchorage system needed to transfer these loads.
3.
Are any masonry walls subject to a thennal gradient which would cause additional stresses and/or cracking.
If so, what are the locations of the walls, loads, load combinations and allowable stresses.
4 Some of the masonry walls seem to have a support column at one end and i
not at the other (e.g., Class 1 wall shown on drawing A-74). Discuss the design and means of support for these types of walls.
5.
In response to the staff's information request No. 3 dated April 21, 1980, the concrete masonry walls are designed in accordance with Fational Concrete Masonry Association's (NCMA) " Specification for the Design and Construction of Load Bearing Concrete Masonry." From the stress criteria established on the basis of NCMA specification as shown in Table 2 it is noted that tension in flexure is allowed.
It accears that to rely on the tensile strength of the concrete masonry wall for seismic resistance is inconsistent with basic design philosophy of concrete structures for nuclear power plants. Further-more, compared with ATC-3 (Applied Technology Council) allowables recomended, the NCMA allowable tensile stresses are much too high, especially if these stresses are multiplied by a factor of 1.67 as indicated in the last column of Table 1.
In accordance with an article in the August issue of Civil Engineering (p. 56) ATC-3 is
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proposing the elimination of the use of unreinforced masonry walls for future construction and providing boundary support for existing walls, unless extensive tests will be made to substantiate the NCMA allowable tensile stresses. Demonstrate the design adequacy of the masonry walls j
without having to rely on tensile stresses or justify their usage, j
6.
For the examples submitted with your letter of July 8,1980 j
(a) Discuss the effects of 3 components of earthquake loading.
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( b) Identify the other loads imposed on this wall (magnitudes, direction andlocation).
(c) Indicate by reference to the drawings, the location of these walls.
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-2, (q.) Discuss the appropriateness of
-ing the uncracked moment-of-inertia under simultaneous loading.
(e) Discuss and substantiate the mechanism through which composite action of multiwythe wall is assumed to occur.
(f) Provide the response spectra used in the analysis. Discuss if these spectra are the envelope or average of the top and bottom spectra.
Indicate the damping values used.
e 7.
For span #1 (Figure 1 or 2 of.the example submitted kith your letter of July 8,1930) discuss the attachment of the wall to the floor to justify the simply supp,orted assumption.
8.
In your sample calculation on page 6 provide your justification for neglecting the eccentric moment (p x e), noting that it will exert a torsional moment on your idealized beam.
9.
With regard to part Y, p. 7 of your calculation of masonry wall support column design:
(at) Indicate if the columns carry any loads other than those imposed by the masonry wall.
If so, include them in the design of the column.
(b) Consider all the loads imposed by the masorry wall (see item 2 of this enclosure) including the effects of 3 components of earth-quake in the design of the support column.
10 Provide detailed calculations for three representative masonry walls (at least one wall being of multiwythe construction and one in the of the enclosure)which experience all the loads identified in Table 1 reactor building to your letter of July 8,1980.
If there are walls l
l which experience loads such as LOCA, SRY, and thennal in addition to the loads in Table 1, provide detailed calculations for one of these walls also. The calculations should identify all the loads and load combinations, provide response spectra and damping values used, and l
provide details of wall connection all around. Discuss and substantiate all assumptions used.
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