ML20148F809

Forwards Recent NRC Memos Re Problems W/Pipe Support Base Plate Design.Staff Will Inform Bd of Conclusions After Study of Addl Info from Licensee.(See ANO:7811020332,7901030033, & 7811020343.)

ML20148F809
Person / Time
Site:	Indian Point
Issue date:	10/24/1978
From:	Beverly Smith NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD)
To:	Buck J, Mike Farrar, Quarles L NRC ATOMIC SAFETY & LICENSING APPEAL PANEL (ASLAP)
References
NUDOCS 7811090188
Download: ML20148F809 (2)

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=s UMTED STATES kC p~ 1, NUCLEAR HEGULATORY COMMISSION .

UB g , D,Z1 g WASWNGT0% D C.20555 ,,' p k ***e / October 24, 1978 gC()N kpE Oog Michael C. Farrar, Esq., Ch' airman Dr. John H. Buck Atomic Safety and Licensing Atomic Safety and Licensing Appeal Board Appeal Board U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission O Washington, D. C. 20555 Washington, D. C. 20555 Dr. Lawrence R. Quarles Route 4, Box 174 e 9 Charlottesville, Virginia 22901 g#!

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In' the Matter of '- '

1 CONSOLIDATED EDIS0N COMPANY OF NEW YORK, INC and 7 c;

Gg@g\dg g-POWER AUTHORITY OF THE STATE OF NEW YORK (Indian Point Station, Units 1, 2 and 3) @#V Docket Nos. 50-3, 50-247 and 50-286  % /

co eo Gentlemen:

Enclosed are recent memoranda discussing certain problems experienced in connection with pipe support base plate design. The Staff is in the process of obtaining additional detailed information from the Licensee concerning the characteristics of the design for Indian Point Station, Units 1, 2 and 3.

After the information is compiled and analyzed, the Staff will inform the Board and parties if any additional action is required.

Sincerely, ul y f j >w Barry H. Smith Counsel for NRC Staff

Enclosure:

Memo 9/28/78 V. -Stello, -

NRR, to M. Grossman, OELD, - -

w/ enclosure cc: See page 2. . _

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Enclosure:

Edward J. Sack, Esq. "

Jeffrey C. Cohen, Esq.

Richard C. King, Esq.

Leonard M. Trosten, Esq.

Honorable George V. Begany David S. Fleischaker, Esq. .

Mr. Samuel Chilk Dr. Franklin C. Daiber Mr. R. Beecher Briggs Samuel W. Jensch, Esq.

Atomic Safety and Licensing _

Board Panel -

Atomic Safety and Licensing '

Appeal Board Panel Docketing and Service Section

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• s*** GEP 2 g y MEMORANDUM FOR: Milton ~J. Grossman, Hearing Division Director an.d Chief Counsel, OELD FROM: Victor Stello, Jr,, Director Division of Operati.ng Reactors, NRR

SUBJECT:

BOARD NOTIFICATION - PIPE SUPPORT BASE PLATE DESIGN The attached memorandum to Roger Mattson, dated June 28, 1978, presents information concerning failures of safety-related pipe supports at Millstone 1 and design deficiencies on similar equip-ment at Shor'eham Unit 1. As indicated in the attachment, two factors appeared' to contribute to failure of anchor-bolt connec-tions of pipe supports. Theseare,1) the design assumption that base plates perform structurally as rigid load-bearing members when they may be flexible members, and 2) incorrect anchor bolt torquing.

Recent audits of Architectural Engineering firms and assessments of the actions taken at Millstone, as noted in the attachment, c provided the following general information: .

1. During the last few years, the' A/Es have changed their des _ign and installation procedures for concrete embedded pipe supports.

2. Past-and current des.ign and installation' procedures vary amo.ng the A/Es,

3. In the past many of the pipe support designs have been con-tracted, and were done with methods not known by the principal A/Es, .

We have concluded that the more detailed information required must be obtained from each operating facility, We are preparing a generic 7s // o20 332-

Milton J. Grossman - 2-

-letter to each operating facility requesting detailed design, installation, and testing information of concrete-embedded anchor-bolted pipe supports of safety-related equipment.

We recommend that this inforr6ation be' provided to the following Boards:

1. Monticello (FTL) 2 Indian Point 1,2,3 (Seismic Design)

We will provide an assessment of this issue upon completion of l our evaluations.

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Victor Stel'10, Jr., Director -

Division of Operating Reactors Office of Nuclear Reactor Regulation

Enclosure:

June 28, 1978 memo, Stello to Mattson cc w/ enclosure:

D. Vassallo V. Stello -

R. Mattson R. Bevan' L. 01shan L. Nichols V. Noonan A. Schwencer T. Ippolito '

d. Fair '

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MEMORANDUM FOR: R. J. Mattson, Director ,

Division of Systems Safety l

FROM: Victor Stello, Jr., Director l

Division of Operating Reactors

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SUBJECT:

OPERATING EXPERIENCE MEMORANDUM NO. 13 PIPE SUPPORT BASE PLATE PROBLEM

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PROBLEM -

Recently during inservice inspections at Millstone Unit 1, structural failures of rigid pipe supports for class 2 safety equipment were observed. These were conducted ih.accordance inspections,with recently Section implemented XI of the ASME at Millstone, Code, as endorsed by regul'ation, 10 CFR 50.55 a(g), in February 1976.

Several' base-plate anchor bolts of pipe supports in the Core Spray l- and the Low Pressure Coolant Injection Systems at Millstone were not properly embedded; and, in some cases the anchor bolts were completely pulled out and no supporting function was provided.

Deficiency reports, in accordance with 10 CFR 50.55(e), filed by -

Long Itland Lighting Company, on Shoreham Unit 1, indicate that '

design of base plates with drilled anchor bolts using rigid plate assumptions has resulted in underestimation of loads on some anchor bolts. Inspection of anchor bolt installations at Shoreham has shown over fifty percent of the bolt installations were deficient. Supports for both piping systems and electrical raceways have been reported as deficient at Shoreham. ,

PRESUMED CAUSE It is currently believed that two interacting factors contribute to the failure of the supports. First, the design assumption that l

the base plates perform structurally as rigid instead of flexible members may provide low estimates of imposed loads on the supports.

Secondly, incorrect anchor bolt embedment may also contribute to insufficient support.

The attached memorandum from V. Noonan to B. Grimes,. dated i

, June 2, 1978, provides' additional information. . i

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Depending on equipment layout, improperly designed or installed anchor '

supports could: <

1, result in loss of support function in some cases; and,

2. result in high stressing of piping systems during a seismic event or during a significant flow transient.

REPAIR Millstone with assistance from Teledyne Engineering has completed design modifications and repairs. These changes include increased base plate thickness and larger anchor bolts for failed supports. ,

Shoreham in conjunction with Stone and Webster is evaluating both piping and electrical type supports. The review is scheduled to be completed by December, 1978 DDR ACTION The Engineering Branch will review the design procedures used on operating piants to determine anchor bolt loads, the techniques used to determine load ratings for anchor bolts, and the installation procedures.

This review will be done through an A/E vendor inspection audit in conjunction with IE. These A/E audits will be started during early i July, 1978.

We anticipate that criteria will be developed for design and installation of base plate-anchor bolt assemblies, and those operating plants requiring corrective action will be identified.

Additionally EB staff will further assess the occurrence and corrective actions taken at Millstone.

PEC0!HE!!DATIONS ,,' .

We rec'ommend that this problem be addressed on all Cp and OL reviews.

At this time it appears that consicerations should be given to the analytical methods used to.. determine whether or not base plates behave as flexible or rigid members. This in turn may effect the anchor bolt size and embedment to properly cope with loads imposed on the supports.

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It may bej app _ropriateito' require that applicants: proiride 'for- review -

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~ 1'.1 methods for determining _ base a p1' te thickness and' anchor ' bolt loads; 2.. criteria,for anchor bolt installation; and,.

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criterialoads.-

cyclic: for.: load rating techniques for anchor bolts, including-t Weishall issue with coordinate your staff. our meetings, discussions and evaluations'of this' Supplemental information will be provided..

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1 Reviewer: EJ. Fair

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Enclosure:

r Memorandum l dated 6/2/78 cc:

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E._G. Case- ^

S. Hanauer -

R. S. Boyd.

H. R. Denton F. Schroeder )

DSS AD's DOR'AD's 00R BC's

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.J. Fair M. Nichols W. Rutherford j

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MEMORANDUM FOR: B. K. Grimes, Assistant Director for Engineering and Projects, DOR - '

D. G. Eisenhut, Assistant Director for Systems and Projects, DDR FROM: Acitag Branch Chief, -

Engineering Branch,-DDR .

SUBJECT:

PIPE SUPPORT BASE ' PLATE PROBLD4 The Engineering Branch, Division of Operating Reactors, has contacted l

i Bechtel, Bergen - Paterson, Gilbcrt, and Stone & Webster in regard to their past and current design procedures for support base plates utilizing drilled anchor bolts. Bechtel and Stone & Webster l

indicated that they became aware of base plate flexibility effects on anchor boltepull-out loads within the past couple of years and are now considering this in current designs. Gilbert and Bergen - Paterson indicated they are using rigid plate assumptions for calculating bolt loads.

, Review of the support redesigns at Millstone shows a considerable increase in base plate thickness and anchor bolt sizes over the previous design. The original designs by Bergen - Paterson did not meet the current rigidity requirements used by Stone & Webster.

Design deficiency reports by Long Island Lighting Company on Shoreham show that consideration of base plate flexibility has "

increased the pull-out loads on some bolts, and inspection of the supports has shown that approximately 55 percent of the anchor bolts had incorrect embedment lengths.

Currently, f&E is considering whether Stone & Webster should be investigated for a Part 21 deviation and will be further investigating this matter.

• The Engineering Branch considers the problem at Millstona where several support plates were pulled out to be a combination of base plate flexibility ana anchor bolt design problems. Since the anchor bolts were never tested for cyclic loadings, and the lines at Millstona experienced flow induced vibrations, the capability of tne anchor bolts to withstand cyclic loadings should be addressed.

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Based on the above infomation, the Engineering Branel recounds ..

that this be considered a generic item for all operati .g plants, and a vendor inspection program be impicmented with I&E to review the vendor design procedures used for analyzing support base plates .

utilizing drilled anchor bolts alon'g with the field instal 11ation procedures utilized in installing the anchor bolts. Also, the lo'd a rating techniques used by the anchor bolt manufacturers for cyclic -

loadings should be reviewed. The Engineering Branch has talked ,

with ILE and consider the vendor' inspection program to be the most efficient method of completing the necessary review. The Engineering Branch esticates approximately 15 man-weeks will be required to review. design procedures used by vendors and A/E firms. The Engineering Branch will set up a meeting with both AD's to determine the interface between the Engineering Branch and I&E required to implement the review. -

l The Engineering Branch is in the process of preparing a feedback memo to June

'ty DSS on the base plate problem which is expected to be completed 9, 1978.

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Etisinal s,ignQ),z.i 4 V. S. Noonan, Acting Branch Chief Engineering Branch Division of Operating Reactors ec: V. Stello, Jr., DDR W. Rutherford IE U. Potopous , IE ,

R. Mattson, Oss

. J. P. Knight, DSS R. Bosnak, Dss ,

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