ML19296A813

Responds to IE Bulletin 79-02,Revision 2.Concrete Expansion Anchors Not Used in Concrete Block Walls to Attach Piping Supports in Seismic Category I Sys.Pipe Supports W/Concrete Expansion Anchors Have Used Structural Steel Shapes

ML19296A813
Person / Time
Site:	Seabrook
Issue date:	01/04/1980
From:	Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
IEB-79-02, IEB-79-2, NUDOCS 8002190073
Download: ML19296A813 (3)

Text

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U e pusucsenvics Companyof New Hamr= hire SEABROOK STATION Engineering Office:

20 Tumpika Road Westborough, MA 01581 January 4, 1980 SBN-ll3 Ref SBU-32861 T.F. B 4.2.5 U.S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Pruscia, Pennsylvania 19406 Attention: Office of Inspection and Enforcement

Reference:

1. Docket No. 50-443 and 50-444

2. NRC letter dated November 8, 1979

3. IE Bulletin No. 79-02 Revision 2

Subject:

Pipe Support Base Plate Designs Using Concrete Expansion Anchor Bolts

Dear Sir:

We have reviewed NRC Bulletin No. 79-02 Revision 2 and offer the following responses to applicable Items:

Item 2 - Additional Action Requested in Rev. 2 of IE Bulletin 79-02 The Bulletin factors of safety were intended for the maximum support load including the SSE. The NRC has not yet been provided adequate justification that lower factors of safoty are acceptable on a long term basis. Lower factors of safety are allowed on an interim basis by the provisions of Supplement No. 1 to IE Bulletin No. 79-02. The use of reduced factors of safety in the factored load approach of ACI 349-76 has not yet been accepted by the NRC.

Item 2 - Response All concrete expansion anchors are designed for worst case loadings which includes consideration of SSE loadings. All of'the concrete expansion anchors are designed with a safety factor of four (4) or greater which satisfies the criteria of IE Bulletin 79-02.

Item 5 - Additional Action Requested in Revision 2 of IE Bulletin 79-02 Determine the extent that expansion anchor bolts were used in concrete block (masonry) walls to attach piping supports in Seismic Category I systems (or safety related systems as defined by Revision 1 of IE Bulletin No. 79-02). If expansion 8002190 (

'D.S. Nuclear Regulatory Commission i Page 2 SBN-ll3 anchor bolts were used in concrete block walls:

a. Provide a list of the systems invol red, with the number of supports, type of anchor bolt, line size, and whether these supports are accessible during normal plant operation.

b. Describe in detail any design consideration used to account for this type of installation.

c. Provide a detailed evaluation of the capability of the supports, .:cluding the anchor bolts, and block walls to meet the design loads. The evaluation must describe how the allowable loads on anchor bolts in concrete block walls were determined and also what analytical method was used to determine the integrity of the block walls under the imposed loads. Also describe the acceptance criteria, including the nunerical values, used to perform the evaluation. Review the deficiencies identified in the Information Notice on the pipe supports and walls in Trojan to determine if a similar situation exists at ycur facility with regard to supports using anchor bolts in concrete block walls.

d. Describe the results of testing of anchor bolts in concrete block walls and your plans and schedule for any further action.

Item 5 - Response Concrete expansion anchors are not used in concrete block walls to attach piping supports in Seismic Category I systems.

Item 6 - Additional Action Recuested in Rev. 2 of IE Bulletin 79-02 Determine the extent that pipe supports with expansion anchor bolts used structural steel shapes instead of base plates. The systers and lines reviewed must be consistent with the criteria of IE Bulletin No. 79-02, Revision 1.

If expansion anchor bolts were used as described above, verify that the anchor bolt and structural steel shapes in these supports were included in the actions performed for the Bulletin. If these supports cannot be verified to have been included in the Bulletin actions:

a. Provide a list of the systems involved, with the number of supports, type of anchor bolt, line size, and whether the supports are accessible during normal plant operation.

b. Provide a detailed evaluation of the adequacy of the anchor bolt design and installation. The evaluation'should address the assumed distribution of loads on the anchor bolts. The evaluation can be based on the results of previous anchor bolt testing and/or analysis which substantiates operability of the affected system.

c. Describe your plans and schedule for any further action necessary to assure the affected systems meet Technical Specifications operability requirements in the event of an SSE.

U.S. Nuclear Regulatory Commission Page 3 SBN-ll3 Item 6 - Response Many of the pipe supports with concrete expansion anchors have used structural steel shapes instead of base plates. The design of these supports, however, is consistent with the criteria of IE Bulletin No. 79-02, Revision 1.

Item 9 - Additional Action Requested in Revision 2 of IE Bulletin 79-02 All holders of construction permits for power reactor facilities are requested to complete items 5 and 6 for installed pipe supports within 60 days of date of issuance of Revision No. 2. For pipe supports which have not yet been installed,

, document your action to assure that items 1 through 6 will be satisfied. Maintain documentation of these actions on site available for NRC inspection. Report in writing within 60 days of date of issuance of Revision No. 2, to the Director of the appropriate NRC Regional Office, completion of your review and described any instances not previously reported, in which you did not meet the revised (R2) sections of items 2 and 4 and, if necessary, your plans and schedule for resolution.

A copy of your report should be sent to the United States Nuclear Regulatory Commission, Office of Inspection and Enforcement, Division of Reactor Construction Inspection, Washington, D.C. 20555.

Item 9 - Response All supports with concrete expansion anchors are being reviewed to assure compliance with items 1 through 6. This review will be completed prior to the QC sign-off for the installed pipe supports.

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

Very truly yours, u /S f '~'

John DeVincentis Project Manager JDV: tan cc: U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Division of Reactor Construction Inspection Washington, D.C. 20555