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UNITED STATES
% .LE AR REGULATORY COMMISSION
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- a / March 15.1979 OFPC: OcTHE C O*.' .:r:l,!O?.1 R MEMORANDUM FOR: Executiv.; Director j fo'r Operations 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
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f;UCLEAR REGULATORY COMISSIO:1 I 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 Initialhas resulted in underestima-investigation indicated
' tion of loads on some anchor bolts.
that nearly fifty percent of the base plates could not be assumed to behave as rigid plates. In addition, licensee inspection of anchor bolt 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 ~ '
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 risers. The data also show low cycle dynamic failures at loads below - .
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.
- 1. Verify that pipe support base plate flexibility wasofaccounted In lieu supportingfor
- 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 Harch.8, 1979 IE Bulletin flo. 79-02 .
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 ~
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. t
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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:
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(a) Cyclic loads have been considered (e.g. anchor bolt pre.ioad '
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,Inall other bo.its on that base plate should be similarly tested. any event, the test program should assure that each Seismic Category I system will perform its intended function. -
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March 8, 1979 IE Bulletin l'o. 79-02 ,
- 5. 'All holders of operating licenses for power reactor facilities are
- requested to complete items 1 through 4 within 120 days of date of
-i
' 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 -
F as set forth in the regulations and license.
- 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
_w hich have not yet been installed, document your actions to assure '
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 ^
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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y . IE Bulletin flo. 79 02
, 1979 March 8 i LISTING OF IE BULLETINS
,i -
ISSUED IN LAST TWELVE MONTHS -
2 Bulletin Subject Date Issued Issued To f .
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78-03 Potential Explosive 2/8/78 All BWR Power li Gas Mixture Accumula-
- Reactor Facilities tions Associated with -
with an OL or CP 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 . ,
Malfunctioning of All' Power Reactor
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' 78-05 4/14/78 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
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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.I . 'IE Bulletin No. 79 02 March 8, 1979 i ,
I
- LISTING OF IE BULLETIUS I ISSUED IN LAST TWELVE M0:ITHS
! Bulletin Subject Date Issued Issued To l Mo. .
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f.
75-10 Bergen-Paterson 6/27/78 All BWR Power j 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 -
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 .
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79-01 Environmental Qualifica- 2/8/79 All Power Reactor i tion of Class IE Equipment Facilities with an OL or CP s
Enclosure Page 2 of 2 J
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