ML19294B330

Forwards Response to IE Bulletin 79-02,Revision 2,Items 5, 6 & 7

ML19294B330
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	12/08/1979
From:	Broehl D PORTLAND GENERAL ELECTRIC CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
IEB-79-02, IEB-79-2, TAC-12369, NUDOCS 8002280196
Download: ML19294B330 (8)

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gi December 8, 1979 Trojan Nuclear Plant Docket 50-344 License NPF-1 Mr. R. H. Engelken, Director U.S. Nuclear Regulatory Commission Region V Suite 202, Walnut Creek Plaza 1990 N. California Blvd.

Walnut Creek, CA 94596

Dear Sir:

The attached completes Portland General Electric Company's response to items 5, 6, and 7 of IE Bulletin 79-02, Revision 2, dated November 8, 1979, regarding Seismic Category I pipe support base plates which use expansion anchor bolts in concrete block walls.

Sincerely, N

y DJB/JLT/ab Attachment c:

Mr. Lynn Frank, Director State of Oregon Department of Energy Director Office of ISE Division of Nuclear Operations Inspections U.S. Nuclear kegulatory Commission Mr. A. Schwencer, Chief Operating Reactors Branch No. I Division of Operating Reactors U.S. Nuclear Regulatory Commission soo22sonqG

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PGE'S RESPONSE TO IE BULLETIN 79-02, REVISION 2 DATED NOVEMBER 8, 1979 NRC IE Bulletin 79-02, Revision 2 requires all licensees of nuclear power plants to provide responses to Bulletin items 5, 6, and 7 within 30 days of the date of issuance of Revision No. 2.

PGE's responses are provided herein.

Item 5 Detenaine 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 anchor bolts were used in concrete block walls:

Item 5a Provide a list of the systems involved, with the number of supports, type of anchor bolt, line size, and whether these supports are accessible during normal plant operation.

Response to Item 5(a)

The total number of supports for Seismic Category I piping systems which utilize expansion anchor bolts in concrete block walls is 503.

Table 5(a)-1 shows the Seismic Category I systems involved, the number of supports in each system which use expansion anchor bolts in concrete block walls, the range of line sizes per system, and identification of the number of supports in each systeu for which the supports are normally accessible

• or inaccessible during nonaal plant operation.

• Normally accessible refers to those areas of the plant which can be entered during reactor operation.

TABLE 5(a)-1

SUMMARY

OF EXPANSI0ft AfiCHOR COLTS USED Ifl C0f1 CRETE BLOCK WALLS flo. and Type Piping Accessibility I'o. Supports of Expansion System of Supports Seismic Category I With Expansion Anchor Bolt Line Size fio.

fio.

Piping System Anchor Bolts SD(1) W(2)

(Dia.-in.)

Access.

Inaccess.

Chemical Volume Control 149 569 8

3,4,6,8 61 88 Residual Heat Removal 44 184 25 3,8,12,14 39 5

Safety Injecton 81 228 0

4,6,8,14,24 71 10 Containment Spray 28 144 8

3,10,14 21 7

Component Cooling Water 37 172 12 3,4,6,12,14 35 2

Service Water 96 316 0

3,6,8,10,12 34 62 Diesel Fuel 8

32 0

3,6, 8

0 Miscellaneous (3) 60 230 4

3,4,8,10 55 5

TOTAL 503 1875 57 324 179 (1) Phillips self-drilling expansion anchor bolts (SD)

(2) Phillips wedge expansion anchor bolts (W)

(3) Miscellaneous systems include:

Radioactive Gaseous Waste Containment Vent Monitoring Spent Fuel Pool Primary Makeup Water Clean Radioactive Waste Dirty Radioactive Waste tliscellaneous Gas Supply Chilled Water Solid Radioactive Waste Containment Condensate Process Steau Item Sb Describe in detail any design consideration used to account for this type of installation.

Response to Item 5(b)

The original design of most of the Seismic. Category I pipe system supports which use expansion anchors was performed by Bergen-Patterson Corporation.

The codes and standards used, the methods used in the ana!ysis of pipe systems and the design of pipe system supports in accordance with the FSAR, and the methods used to detenaine expansion anchor bolt loads in the original design are described in our response, dated November 21, 1979, to Item 1 of IE Dulletin 79-02, Revision 1.

The typical expansion anchors used in the original design were the Phillips Redhead self-drilling shell type. Allowable loads were based on a factor of safety of 10 against the manufacturer's ultimate load values determined from tests.

In the original design, there was no differentiation between expansion anchor bolt installations in concrete and concrete masonry because the factor of safety of 10 on ultimate pullout loads was considered to be sufficiently conservative for either application.

Item Sc Provide a detailed evaluation of the capability of the supports, including the anchor bolts, and block wall to meet the design loads.

The evaluation uust describe how the allowable loads on anchor bolts in concrete block walls were detenlined 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 numerical values, used to perform this evaluation.

Review the deficiencies identified in the Information Notice on the pipe supports and walls at Trojan to determine if a similar situation exists at your facility with regard to supports using anchor bolts in concrete block walls.

Response to Item 5(c)

The methods and results of analysis for reevaluation of the capability of Seismic Category I pipe support base plates which use expansion anchor bolts and the method used to detenaine allowable values for the bolts in masonry walls are described in our reponse to Item 1 of IE Bulletin 79-02, Revision _.

An extensive reevaluation of the structural integrity of concrete block wall construction to support Seismic Category I pipe restraints, including those which use expansion anchor bolts, has been performed for the Trojan plant.

The results of this reevaluation including the analytical methods used, acceptance criteria applied, deficiencies identified, and corrective actions taken are reported in Licensee Event Report 79-15.

Item 5d Describe the results of testing of anchor bolts in concrete block walls and your plans and schedule fop any further action.

Response to item 5(d)

Results of testing of expansion anchor bolts, including installations in concrete block wall construction, performed to date are reported in our response to Item 4 of Revision 1 of IE Bulletin 79-02. As described in that response, we are planning to perform confinaatory testing of expansion anchors in concrete block walls in order to demonstrate that the allowable values used in the IE 79-02 reevaluation analyses are appropriate for the concrete block wall construction at Trojan.

Item 6 Deteruine the extent that pipe supports with expansion anchor bolts used structural steel shapes instead of base plates.

The systems and lines reviewed must be consistent with the criteria of IE Bulletin fio. 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 pla s and schedule for any further action necessary to assure the affected systems meet Technical Specifications opera-bility requirements in the event of an SSE.

Response to Item 6 Item 6 is not applicable to Trojan because structural shapes were not used, to any significant extent, as pipe support base plates at Trojan and the few supports using structural shapes as base plates were included in the reevaluation analysis.

Item 7 For those licensees that have had no extended outages to perfona the testing of the inaccessible anchor bolts, the testing of anchor bolts in accessible areas is expected to be completed by November 15, 1979.

The testing of the inaccessible anchor bolts should be completed by the next extended outage.

For those licensees that have coupleted the anchor bolt testing in inaccessible areas, the testing in accessible areas should continue as rapidly as possible, but no longer than March 1,1980.

The analysis for the Bulletin items covering base plate flexibility and factors of safety should be completed by November 15, 1979. Provide a schedule that details the completion dates for IE Bulietin No. 79-02, Revision 2, Items 1, 2, and 4.

Response to Item 7 The status of our actions pursuant to the IE Bulletin 79-02, Revision 2, Items 1, 2, and 4 is as follows (see PGE's response dated November 21, 1979 to Revision 1 of IE Bulletin 79-02).

Item 1.

The analytical reevaluation of all Seismic Category I piping system supports (3-in. diameter and larger) which use expansion anchor bolts has been completed.

Item 2.

All expansion anchor bolts which had factors of safety less than two have been repaired to restore the required factor of safety as specified in IE Bulletin 79-02.

Repairs to those expansion anchor bolts which have factors of safety less than five will be completed during the forthcoming refueling outage.

Item 4.

The field testing of representative expansion anchor bolts (approxinately 20% sampling) in Seismic Category I pipe support base plates at Trojan has been completed.

Expansion anchor bolts in RHR system pipe supports were not sample tested because of the potential for high radiation exposures to personnel.

The data obtained for other systems is also representative of the RHR system because of the similarities of pipe support designs and mounting locations.

Although the test data shows that the defect rate for a 95% confidence level slightly exceeds 5%, for the 20% sample size, there were no conditions identified in the testing program which adversely affected the operability of any Seismic Categary I piping system.

Therefore, further testing of existing expansion anchor bolt installations is not planned.

The further action with respect to IE Bulletin 79-02 now planned for Trojan is the confinnatory testing of expansion anchor bolt capacities in concrete block.

TLB/3j f 55.33B15