ML17272A325
| ML17272A325 | |
| Person / Time | |
|---|---|
| Site: | Columbia, Washington Public Power Supply System, Satsop  |
| Issue date: | 03/08/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Strand N WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| References | |
| NUDOCS 7903150070 | |
| Download: ML17272A325 (7) | |
Text
Docket Nos.
50-460 50-397 50-508 50-509 50-513 UNITED STATES NUCLEAR REGULATORY COMMISSION REGION V SUITE 202, WALNUTCREEK PLAZA 1990 N. CALIFORNIA BOULEVARD WALNUTCREEK, CALIFORNIA 94596 March 8, 1979 Washington Public Power Supply System P. 0.
Box 968 3000 George Washington Way
'ichland, Washington 99352 Attention:
Mr. N. 0. Strand Managing Director-Gentlemen:
The enclosed IE Bulletin No. 79-02 is forwarded to you for action.
A written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, R.
H. Engelken Director
Enclosures:
1.
List of IE Bulletins Issued in the past 12 months cc w/enclosures:
M. E. Witherspoon, WPPSS A. D. Kohler, WNP-2, WPPSS J.
P.
VO V903reooe-8
UNITED STATES NUCLEAR REGuLATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT'IASHINGTON, D.C.
20555 March 8, 1979 IE Bulletin No. 79-02 PIPE SUPPORT BASE PLATE DESIGNS USING CONCRETE EXPANSION ANCHOR BOLTS Description of Circumstances:
While performing inservice inspections during a March-April 1978 refueling outage at Millstone Unit I, structural failures of piping supports for'safety equipment were observed by the licensee.
Subsequent licensee inspections of undamaged supports showed a large percentage of the concrete anchor,bolt's 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-'ion of loads on some anchor bolts.
Initial investigation indi'cated 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 fifty percent of the bolt installations to be deficient.
Vendor Inspection Audits by NRC at Architect Engineering firms have shown a wide range of design practices and installation procedures which have been employed for the use of concrete expansion anchors.
The current trends in the industry are toward more, rigorous controls and verifica-tion 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 notch 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 anchor bolts in Seismic Category I systems as defined by Regulatory Guide 1.29, "Seismic Design Classification" Revision 1, dated August 1973 or as defined in the applicable FSAR.
l.
Verify that pipe support base plate flexibilitywas accounted for in the calculation of anchor bolt loads.
In lieu of supporting analysis justifying the assumption of rigidity, the base plates 1of 3
IE Bulletin No. 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'he thickness of the plate.
If the base plate is determined to be flexible, then recalculate the bolt loads using 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.
2.
Verify that the concrete expansion anchor bolts have the following minimum 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.
4 Describe the design requirements if applicable for anchor bolts to withstand cyclic loads (e.g. seismic loads and high cycle operating loads).
Verify from existing gC documentation that design requirements have been met for each anchor bolt in the following areas:
(a)
Cyclic loads have been considered (e.g.
anchor bolt preload is equal to or greater than bolt design load).
In the case of the she'l 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 more than one base plate).
The test should provide verification of sub-items (a) and (b) above.
If the test fails, all other bolts on that base plate should be similarly tested.
In any event, the test program should assure that each Seismic Category 1 system will perform its intended.
function.
J 20f 3
IE Bulletin No. 79-02 Harch 8, 1979 5..
All holders of operating licenses for power reactor-facilities are equested to complete-items 1 through 4 within 120 days of date of issuance of this Bulletin.
A reactor shutdown is not required to be initiated solely for purposes of this inspection above.
f1aintain 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 1 through 4
'nd, if necessary, your plans and sche'dule 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.
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 suppor t base plates which 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, completi.on of, your review and describe any discrepancies in ~ecting items 1, though 4 and, if necessary, your plans and schedule for resolution.
A copy of your repor t should be sent to the United States Nuclear Regulatory Commission, Office of Inspection and Enforcement, Division of Reactor Construction Inspection, Mashington, D.C.
20555.
Approved by GAO B180225 (R0072); clearance expires 7/31/80.
Approval was given under a blanket clearance specifically for identified generic pro bl ems.
Enclosure:
List of IE Bulletins Issued in Last Twelve [months 3of 3
IE Bulletin No. 79-02 March 8, 1979 LISTING OF IE BULLETINS ISSUED IN LAST Tl'JELVE MONTHS Bulletin
-'o.
78-03 78-04 78-05 78-06 78-07 Subject Potential Explosive Gas Mixture Accumulat-ionss Associated with Bl(R Offgas System Oper ations Envir'onmental quali-fication of Certain Stem Mounted Limit Switches Inside Reactor Containment Malfunctioning of Circuit Breaker Auxiliary Contact Mechanism-General Model CR105X Defective Cutler-
- Hammer, Type M Relays Mfth DC Coils Protection afforded, by Air-Line Respirators and Supplied-Air Hoods Date Issued 2/8/78 2/21/78 4/14/78 5/31/78 6/12/78 Issued To All BMR Power Reactor Facil fties with an OL or CP All Power Reactor Facilities with an OL or CP All Power Reactor Facilities with an, OL or CP All Power Reactor Facilities with an OL or CP All Power Reactor Facilities with an OL, all class E and F
Research Rea'ctors with an OL, all Fuel Cycle Facilities with an OL, and all Priority 1
Material Licensees 78-08 Radiation Levels from 6/12/78.
Fuel Element Transfer, Tubes
,All Power and Research Reactor Facilitfes with a Fuel Element Transfer Tube and an OL.
78-09 BNR Drywell Leakage Paths Associated with Inadequate Drywell Closures 6/14/79 All BMR Power Reactor Facilities with an OL or CP Enclosure 2
Page 1 of 2
t IE Bulletin No. 79-02 March 8, 1979 Bulletin Subject No.
LISTING OF IE BULLETINS ISSUED IN LAST TWELVE MONTHS Date Issued Issued To 78-10 78-11 78-12 78-12 A 78-13 Bergen-Paterson Hydraulic Shock Suppressor Accumulator Spring Coils Examination of Mark I Containment Torus Wel ds Atypical Weld Material in Reactor Pressure Vessel Welds Atypical Weld Material in Reactor Pressure Vessel Welds Failures In Source Heads of Kay-Ray, Inc., Gauges Models 7050, 7050B, 7051, 7051B, 7060,
- 70608, 7061 and 7061B 6/27/78 7/21/78 9/29/78 ll/24/78 10/27/78 All BWR Power Reactor Facilities
BWR Power Reactor Facilities for action:
Peach Bottom 2 and 3, Ouad Cities 1 and 2, Hatch 1, Monti-
'ello and Vermont Yankee All Power Reactor Facilities with an OL or CP All Power Reacto'r Facilities with an OL or CP All general and speci fic 1 icensees with the subject Kay-Ray, Inc.
gauges 78-14 79-01
. Deterioration of Buna-N 12/19/78 Components In ASCO Solenoids Environmental gual ifica-2/8/79 tion of Class IE Equipment All GE BWR,facilities with an OL or CP All Power Reactor Facilities with an OL or CP Enclosure 2
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