ML19208D186

Forwards Responses to IE Bulletin 79-02,Revision 1.Results of Cyclic Testing Per Actions 3 & 4 Not Included in Rept. Scheduled for Submittal 790815

ML19208D186
Person / Time
Site:	Cherokee
Issue date:	07/25/1979
From:	Dail L DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
790705-02, 790705-2, NUDOCS 7909280093
Download: ML19208D186 (1)

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i July 5, 1979 Oi.

Mr. J. P. O'Reilly, Director U. S. fluclear Regulatory Comission 7

101 Marietta Street, Suite 3100 Atlanta, Cecrgia 30303 ll b

Re: Cherokee fluclear Station IE Bulletin 79-02, Rev.1 Ouke Files:

CK-1196.02 and CK-1412.ll 3

Dear Mr. O'Reilly:

Enclosed for your use are the responses to Actions 1 throurjh 4 required by IE Bulletin 79-02, Revision 1. Please note that the results of the cyclic testing referred to in Actions 3 and 4 are not included in this report. They are scheduled for submittal to your office on August 15, 1979.

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1 L. C. Dail, Vice President Design Engineering EKM/sr N

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CHEROKEE NUCLEAR STATION Resocnses to USNRC IE Bulletin 79-02, Revision 1 July 5, 1979 Cherokee Nuclear Station is in the early stages of construction and no pipe supports have been installed to date.

The following is a summary, by item, of the extent and manner in whicn Duke Power Company intends to satisfy Actions 1 through 4 of IE Bulletin 79-02, Revision 1.

Response 1:

Duke Power Company will account for base plate flexibility in the calculation of expansion anchor bolt loads for all Seismic Category I pipe support base plates using either a conservative hand calculation method which has been verif'-1 by non-li.aar finite element analysis or a specific non-1, iear finite element analysis for a particular base plate. The models and boundary

, conditions. including appropriate load-displacement character-istics of the anchors, used for the finite element analyses are based on Duke studies and on work performed by Teledyne Engineer-ing Services which was sponsored by a group of thirteen (13) utilities formed to respond to generic items of IE Bulletin 79-02.

Response 2: The minimum factors of safety, between the expansion anchor de-sign load and the anchor ultimate capacity detennined from static load tests, used in Duke Power Company design of pipe supports are as follows:

4 Normal Conditions 3

Upset Conditions Faulted Conditions - 2 Tnese factors of safety are for wedge type and sleeve type ex-pansion anchors which are the only types of anchors which will be used at Cherokee Nuclear Station for Nuclear Safety Related applications.

Expansion anchor installations for Seismic Category I piping supports are restricted to normal weight structural concrete of various nominal strengths. Expansion anchor ultimate load capacities are based on manufacturer's test results and recom-mendations for normal weight concrete and installed concrete strengths.

Cherokee Seismic Category 7 expansion anchor designs will pro-perly account for shear-tension interaction, minimum edge distances and bolt spacing in accordance with manufacturer's test results and recommendations.

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Duke Power Company designs pipe supports to resist all applicable loadings including seismic loads, hydro test loads, normal oper-Response 3:

A support is designed for a ating loads, thermal loads, etc. static or quasi-static load resu bination of the applicable loadings.

Duke the exp:..sion anchors will be as specified in Response 2.

Power Company is now co-sponsoring tests pe a

use at Cherokee Nuclear Station will perfonn ad low amplitude loading (operating loads).

to be complete by July 15, 1979.

All expansion anchors used in Nuclear Safety Related applications The anchors will be Response 4:

will be either wedge type or sleeve type.

inspected for proper installation in accordance with Duke Power Company's Quality Assurance Procedure M-52, " Concrete E Anchor Installation Inspection". expansion anchors are prope manufacturer's recommendations.

Procedure M-52 criteria includes, but is not limited to, inspec-tion of expansion anchor size, type, perpendicularity, torque, embedment depth, spacing, distance to free concrete edge and plate bolt hole over-unauthorized modification of the anchor.

sizing is not specifically inspected for the following reasons:

Duke Power Company Quality A*.surance Procedures prohibit de-viations from design drawing and specifications without 1.

written authorization and approval by the Design Engineering Department.

Cherokee Nuclear Station will qualify each concrete expan-sion anchor operator by installation test and verbal exam-2.

ination on proper installation procedure.

As an additional precaution, Duke Power Com This inspection for evidence of plate bolt hold oversizing.

will be documented for each Nuclear Safety Related pipe support.

In order to address the question of the relationship of cyclic load carrying capacity to installation procedure (anchor preload the tests referred to in Response 3, being performed by Teledyne Engineering Services, and sponsored by th with manufacturer's recommended installation procedures and hve no more preload than is provided by the use of these pro-Based on Duke's understanding of the behavior of expan-sion anchors and on cyclic testing which has been previously per cedures.

fonned on various anchors, Duke Power Company is confident tha the tests will show that the anchors will perform adequately.

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