ML20133M223

Requests Briefing by IE & NRR Re Pipe Support Base Plate Designs Using Concrete Expansion Anchor Bolts.Briefing Should Cover Explanation of Deficiencies,Number of Plants Affected & Significance

ML20133M223
Person / Time
Issue date:	03/15/1979
From:	Ahearne J NRC COMMISSION (OCM)
To:	NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
Shared Package
ML20133M133	List: IA-85-301, Forwards Draft Temporary Instruction Providing Guidance for Inspecting & Evaluating Licensee & CP Holder Responses to IE Bulletin 79-14, Seismic Analysis for As-Built.... Comments Requested by 790723.Supporting Documentation Encl ML20133M130 ML20133M162 ML20133M174 ML20133M190 ML20133M211 ML20133M223 ML20133M232 ML20133M247 ML20133M261 ML20133M289 ML20133M293 ML20133M428 ML20133M451 ML20133M483 ML20133M505 ML20133M523 ML20133M555 ML20133M563 ML20133M575 ML20133M607 ML20133M621 ML20133M635 ML20133M646 ML20133M662 ML20133M685 ML20133M699 ML20133M722 ML20133M737 ML20133M743 ML20133M752 ML20133M757 ML20133M771 ML20133M786 ML20133M842 ML20133M853 ML20133M873 ML20133M891 ML20133M896 ML20133M908 ML20133M919 ML20133M959 ML20133M973 ML20133M996 ML20133N121 ML20133N130 ML20133N148 ML20133N166 ML20133N203 ML20133N381 ... further results
References
FOIA-85-301 NUDOCS 8508130048
Download: ML20133M223 (1)

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UNITED STATES

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%.LE AR REGULATORY COMMISSION

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March 15.1979 OFPC: OcTHE C O*.'.:r:l,!O?.1 R MEMORANDUM FOR:

Executiv.; Director fo'r Operations j

FROM:

John Ahearne (' :,

I would appreciate receiving a briefing by I&E and NRR on the attached subject.

The briefing should cover an explanation of the deficien~cies, number of plants to be affected, and the significance. Of particular interest would be the question of potential further action that might be required to these plants.

Attachment cc: Chairman Hendrie Commissioner Gilinsky Commissioner Kennedy Commissioner Bradford Mr. Chilk #

Mr. MaGee Iv\\'kbJkC$'b w

8508130048 850703 PDR FOIA

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UtlITED STATES

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f;UCLEAR REGULATORY COMISSIO:1 OFFICE OF INSPECTI0t! Al;D Ei:F0P.CEMElli l

WASHIllGTO?l, D.C.

20555 March 8, 1979 l

IE Bulletin fio. 79-02 PIPE SUPPORT BASE PLATE DESIGilS USItiG C0iCRETE E Description of Circumstances:

While performing inservice inspections during a Narch-April 1978 refueling outage at Millstone Unit 1, structural failures of piping Subsequent supports for safety equipment were observed by the lic the concrete anchor bolts were not tightened properly.

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

Island Lighting Company on Shoreham Unit 1, indicate that design of base plates using rigid plate assumptions has resulted in underestima-Initial investigation indicated tion of loads on some anchor bolts.

that nearly fifty percent of the base plates could not be assumed to In addition, licensee inspection of anchor bolt behave as rigid plates.

installations at Shoreham has shown over fif ty percent of the bolt installations to be deficient.

Vendor Inspection Audits by ?!RC at. Architect Engineering firms have shown a wide range of design practices and installation procedures The which have been employed for the use of concrete expansion anchors.

current trends in the industry are toward more rigorous controls and

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verification of the installation of the bolts.

The data available on dynamic testing of the concrete expansion anchors show fatigue failures can occur at loads substantially below the bolt static capacities due to material imperfections or ndtch type stress The data also show low cycle dynamic failures at loads below -

risers.

the bolt static capacities due to joint slippage.

Action to be Taken by Licensees and Permit Holders:

For pipe support base plates that use concrete expansion anc in Seismic Category I systems as define Design Classification" Revision 1, dated August 1973 or as defined applicable FSAR.

Verify that pipe support base plate flexibility was accounted for In lieu of supporting 1.

in the calculation of anchor bolt loads.

analysis justifying the assumption of' rigidity, the base plates I of 3 l

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q IE Bulletin flo. 79-02 Harch.8, 1979 should be considered flexible if the unstiffened distance.between the member welded to the plate and the edge of the base plate is greater than twice the thickness of the plate.

If the base plate is determined to be flexible, then recalculate the bolt loads usino

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an appropriate analysis which will account for the effects of shear. - tension interaction, minimum; edge distance and proper bolt

. spacing.

This is to be done prior to testing of anchor bolts. These calculated bolt loads are referred to hereafter as the bolt design loads.

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2.

Verify that the concrete expansion anchor bolts have the following

-mini. mum factor of safety between the bolt design load and the bolt ultimate capacity determined from static load tests (e.g. anchor bolt manufacturer's) which simulate the actual conditions of installation (i.e., type of concrete and its strength properties):

a.

Four - For wedge and sleeve type anchor bolts, b.

Five - For shell type anchor bolts.

3.

Describe.the design requirements if applicable for anchor bolts to withstand cyclic loads (e.g. seismic loads and high cycle operating loads).

4.

Verify from existing QC documentation that design requirements have been met for each anchor bolt in the followinc areas:

(a)

Cyclic loads have been considered (e.g. anchor bolt pre.ioad '

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is equal to or greater than bolt design load).

In the case of the shell' type, assure that it is not in contact with the back of the support plate prior to preload testing.

(b) Specified design size and type is correctly installed (e.g. proper embedment depth).

If sufficient documentation does not exist, then initiate a testing program that will assure that minimum design requirements have been met with respect to sub-items (a) and (b) above. A sampling technique is acceptable.

One acceptable technique is to randomly select and test one anchor bolt in each base plate (i.e. some supports may have core than one base plate). The test should provide verification of sub-items (a)and_(b)above.

If the test fails, all other bo.its on that base plate should be similarly tested.

In any event, the test program should assure that each Seismic Category I system will perform its intended function.

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e IE Bulletin l'o. 79-02 March 8, 1979 5.

'All holders of operating licenses for power reactor facilities are requested to complete items 1 through 4 within 120 days of date of

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' issuance of this Bulletin. A reactor. shutdown is not required to be initiated solely for purposes of this inspection above.

Maintain documentation ~ of any sampling inspection of anchor bolts required by item 4 on site and available. for NRC inspection. Report in writing within 120 days of date of Bulletin issuance, to the Director of the appropriate NRC Regional Office, completion of your verifica-tion and describe any discrepancies in meeting items I through 4 and, if necessary, your plans and schedule for resolution.

For planned action', a final report is to be submitted upon completion of your action. A copy of your report (s) should be sent to the United States Nuclear Regulatory Commission, Office of Inspection

'and Enforcement, Division of Reactor Operations Inspection, Washington, D.C.

20555. These reporting requirements do not preclude nor substitute for the applicable requirements to report as set forth in the regulations and license.

F 6.

All holders of construction permits for power reactor facilities are requested to complete items 1 though 4 for installed pipe support base plates with concrete anchor bolts within 120 days of date of issuance of this Bulletin.

For pipe support base plates

_ hich have not yet been installed, document your actions to assure w

that items 1 though 4 will be satisfied.

Maintain documentation of these actions on site and available for NRC inspection. Report in writing within 120 ' days of date of Bulletin issuance, to the Director of the appropriate NRC Regional Office, completion of your review i

and describe any discrepancies in meeting items 1 though 4 and, if necessary, your plans and schedule for resolution. A copy of your report should be sent to the United States i;uclear Regulatory Commission, Office of Inspection and Enforce.T.ent, Division of

-Reactor Construction Inspection, Washington, D.C.

20555.

Approved by GAO B180225 (R0072); clearance expires 7/31/80. Approval

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was given under a blanket clearance specifically for identified generic problems.

Enclosure:

List of IE Bulletins Issued in Last Twelve Fonths t

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IE Bulletin flo. 79 02 March 8

, 1979 i

LISTING OF IE BULLETINS

,i ISSUED IN LAST TWELVE MONTHS 2

f Bulletin Subject Date Issued Issued To j

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l 78-03 Potential Explosive 2/8/78 All BWR Power Gas Mixture Accumula-

• Reactor Facilities i

with an OL or CP tions Associated with BWR Offgas System

- Operations 78-04 Environmental Quali-2/21/78 All Power Reactor fication of Certain Facilities with an Stem Mounted Limit OL cr CP Switches Inside Reactor Containment

' 78-05 Malfunctioning of 4/14/78 All' Power Reactor

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Circuit Breaker Facilities with an Auxiliary Contact OL or CP

t. de Rb5X 78-06 Defective Cutler-5/31/78 All Power Reactor Hammer, Type M _ Relays facilities with an With DC Coils OL or CP 78-07 Protection afforded 6/12/78 All Power Reactor by Air-Line Respirators Facilities with en and Supplied-Air Hoods OL, all class E and F Research Reactors with an OL, all Fuel Cycle Facilities with an OL, and all Priority 1 Material Lic'ensees 78-08 Radiation Levels from 6/12/78 All Power and Fuel Element Transfer Research Reactor Tubes Facilities with a Fuel Element transfer tube and an OL.

78-09 BWR Drywell Leakage 6/14/79 All BUR Power Paths Associated with Reactor Facilities In. adequate Drywell with an OL.or CP Closures Enclosure Page 1 of 2 e

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'IE Bulletin No. 79 02 i

March 8, 1979 I

LISTING OF IE BULLETIUS I

ISSUED IN LAST TWELVE M0:ITHS Bulletin Subject Date Issued Issued To l

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j 75-10 Bergen-Paterson 6/27/78 All BWR Power Hydraulic Shock Reactor Facilities l

Suppressor Accumulator with an 0L or CP i

Spring Coils i

78-11 Examination of Mark I 7/21/78 BWR Power Reactor Containment Torus Facilities for Welds action:

Peach j

Bottom 2 and 3, Quad Cities 1.and 2, Hatch 1, Ibnti-l cello and Vermont Yankee i

78-12 Atypical Weld Material 9/29/78 All Power Reactor in Reactor Pressure Facilities wi~th' an Vessel Welds OL or CP 78-12A

. Atypical Weld Material 11/24/78 All Power Reactor

- in Reactor Pressure Facilities with an Ve'ssel Welds OL or CP 78-13 Failures In Source Heads 10/27/78 All general and -

of, Kay-Ray, Inc., Gauges specific licensees Models 7050, 70503, 7051, with the subject 70518, 7060, 70503, 7061 Kay-Ray, Inc.

and 7061B gauges 78-14 Deterioration of Buna-N 12/19/78 All GE BWR facilities Components In ASCO with an~0L'or CP Solenoids 79-01 Environmental Qualifica-2/8/79 All Power Reactor

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i tion of Class IE Equipment Facilities with an OL or CP s

Enclosure Page 2 of 2 J

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