ML19242B260

Submits Response to IE Bulletin 79-02,Revision 1,re Plant Design.Info Pertains to Project Design Procedure & Spec for drilled-in Anchors,Cyclic Loadings & Pipe Support Base Plate Configurations

ML19242B260
Person / Time
Site:	05000516, 05000517
Issue date:	07/06/1979
From:	Plaskon R LONG ISLAND LIGHTING CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
JNRC-234, NUDOCS 7908070784
Download: ML19242B260 (3)

Text

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• H IC K SVI LLE, NEW YORK 11801 July 6, 1979 JNRC-234 Mr. Boyce Grier, Director Office of Inspection & Enforcement, Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 Jamesport Nuclear Power Station - Units 1 & 2 Inspection & Enforcement Bulletin 79-02; 79-02 Rev 1 Docket Nos. 50-516 50-517

Dear Mr. Grier:

r In reply to Inspection & Enforcement Bulletin 79-02 as revised on June 21, 1979, we have rc/iewed the Jamesport Nuclear Power Station (JNPS) design and submit the following response.

The design for attaching pipe supports in JNPS is based on embedded base plates, embedded strip plates and/or base plates with Richmond inserts which are cast in place. The use of drilled-in concrete anchors is not preplanned. However, in the event that support attachment plates must be located where no embedment or Richmond inserts exist, drilled-in concrete an: hor bolts may have to be used.

If this becomes the case, the JNPS pipe suppor" base plates will be designed in accordance with Stone 6 Webster generated procedures and installed by a drilled-in anchor specification which vill address the four items of the referenced NRC Bulletin as described below:

1. A Stone & Webster generic procedure has been developed which will be applied to the JNPS common pipe support base plate configurations to account for plate flexibility in determining drilled-in anchor bolts design loads. In this procedure, the finite element analysis technique is ured to develop load factors which are applied to anchor bolt desion loads to provide for the affects of plate flexibili .

A finite element model will be used to determine loads in the drilled-in anchor bolts. Plate flexibility, anchor stiffness, stiffening effect of member attached to the plate, as well as concrete flexibility are represented in the 7908070vI e c.

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Mr. Boyce Grier July 6, 1979 JNRC-234 Page 2 model. The element model considers pure plate bending, appropriate for the analysis of flexible base plates.

The contact boundary conditions at the interface of the plate and concrete, and plate and drilled-in anchors are satisfied in the solution. Forces are applied as couples and axial forces distributed to nodes of the attached member. The ANSYS 3 finite element package will be used for analysis.

2. The Project design procedure and specification for drilled-in anchors at JNPS will describe the design loads, purchasing requirements and installation for wedge-type anchor bolts.

The average ultimate strength of bolts will be a unimum cf four times the design value used in the design procedure.

This minimum factor of safety of four is based a the average ultimate capacity determined from static lead test conducted by anchor manufacturers in 3000 psi concrete.

The anchor bolt installation torques and ultimate capacity will be verified from manufncturer's test data and/or on-site testing. Shell-type anchor bolts will not be used for JNPS Category I pipe support design.

3. To account for cyclic loadings, the JNPS design procedure will use a consei7ative design load with a minimur.. factor of safety of four with respect to the average ultimate bolt capacity. Conclusions of the Fast Flux Test Facility (FFTF)

Report on " Drilled-In Expansion Bolts Under Static and Alternating Load" (BR-5853-C-4, dated January 1975) indicate that properly installed anchors per' atisfactorily under cyclic loads. The installation requ. ;ments of the specifi-cation will ensure proper bolt installation.

4. The JNPS specification for drilled-in anchors will require that the minimum installation torque for proper setting of the anchors shall devalop a bolt preload of at least 1.5 times the bolt design load. All Category I anchors will be torque tested to 80% of this torque value, assuring cyclic load capability.

The JNPS specification for drilled-in anchors will require all bolts to be stamped with a mark, visible after instal-lation, indicating bolt length. This will enable field 507 540

hr. Boyce Grier July 6, 1979 JNRC-234 Page 3 quality control to determine tilat the proper length bolts have been installed.

Should you require further information, please do not hesitate to contact us.

Very truly yours,

.Lf V R. E. Plaskon Assistant Project Manager Jamesport Nuclear Power Station LG/dm cc: Mr. John G. Davis, Director Office of Inspection & Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20545

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