ML18051A860
| ML18051A860 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 04/18/1984 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Vandewalle D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| LSO5-84-04-040, LSO5-84-4-40, NUDOCS 8404230022 | |
| Download: ML18051A860 (5) | |
Text
Docket No.
50-255 LS05-84-04-040
- Mr. David J. VandeWalle Nuclear Licensing Administrator Consumers Power Company 1945 W. Parnall Road Jackson, Michigan 49201
Dear Mr. VandeWalle:
April 18, 1984 Docket
~*
NRC PDR Local PDR ORB #5 Reading NSIC DCrutchfield LA WPaulson EJordan JGrace ACRS (IO)
SEPB
SUBJECT:
STEAM GENERATOR INSPECTION AND PLUGGING CRITERIA -
Palisades Plant As the result of the meetings held on April 9 and 10, 1984, the NRC staff has identified additional information that is needed to complete our review of your assessment of degradation mechanisms, tube plugging margin evaluation, and plugging criteria for the Palisades steam generators.
He will need your response to the enclosure by April 23, 1984 in order to maintain our current review schedule based on your projected heatup date of May 17, 1984.
The questions in the enclosure were telecopied to you on April 13, 1984.
It is our understanding that you will formally submit the results of the steam generator tube inspection and proposed repair criteria for NRC staff review and approval.
Enclosure:
As stated cc w/enclosure Dlli/J #5 WPaulson:jc
~- 11i /84
,,,----8404230022 840418 PDR ADOCK 05000255 P
PDR w\\~
DL:ORB #5 kf\\,DCqrutchf i el d U
If~ /84 Sincerely, Original signed by Walter Paulson for Dennis M. Crutchfield, Chief Operating Reactors Branch #5 Division of Licensing sE o I
- 1 I
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Mr. David J. Vande'r.'alle cc M. I
- Mi 11 er, Esq u i re Isham, Lincoln & Beale SuHe 4200 One First National Plaza Chicago, Illinois 60670 Mr. Paul A. Perry, Secretary Consumers Power Company 212 West Michigan Avenue Jackson, Michigan 49201 Judd L. Bacon, Esquire Consumers Power Company 212 West Michigan Avenue Jackson, Michigan 49201 James G. Keppler, Regional Administrator Nuclear Regulatory Commission, Region III*
79S Roosevelt Road Glen Ellyn, Illinois 60137 Township Supervisor
- Covert Towns hi Route l, Box l 0 Van Buren County, Michigan 49043 Office of the Governor (2)
Room.l -*capitol Building Lansing, Michigan 48913 Palisades Plant ATTN:
Mr. Robert Montross Plant Manager Covert, Michigan 49043 U. S. Environmental Protection Agency Federal Activities Branch Region V Office ATTN:
Regional Radiation Representative 230 South Dearborn Street Chicago, Illinois 60604 Resident Inspector c/o U.S. NRC Palisades Plant Route 2, P. 0.. Box 155 Covert, Michigan 49043 Lee E. Jager, P.E., Chief Environmental and Occupational
. Health Services Administration*
Michigan Department of Public Health 3500 N. Logan Street Post Office Box 30035 Lansing, Michigan 48909
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REQUEST FOR ADDITIONAL INFORMATION PALiSADES PLANT - MEETING OF 4/10/84
- 1. Burst pressure data for uniformly thinned tubes obtained by Battelle - Pacific Northwest Laboratory and Combustion Engineering indicates that variation in burst pressures can be from 1200 psi to 6000 psi for tubes thinned to a 15-20% remaining wall thickness.
The data presented by Westinghouse does not seem to include all data points.
A 95/95 lower tolerance limit established after inclusion of all data points would predict lower burst pressures for steam lirie break and would impact the proposed plugging limit.
Provide a clarification of this apparent discrepancy.
- 2.
The bending stresses due to the rotation of the tube sheet, flow induced vibration, and thermal growth mismatch between tube and shell have not been addressed for normal operation and accident conditions.
The failure analysis of defects with limited circumferential and axial extent should*take these stresses into account.
- 3.
Verify that the loads on steam generator tubes during a LOCA are the same as presented earlier on 2/2/84 and contained in CE Report NP-2652 - Nov. 1982.
- 4.
It is not clear what stress concentration factor has been used for circumferential cracks and limited axial extent defects in the fatigue evaluation.
- 5.
The methodology used to modify the relations to account for limited axial and azimuthal extent defects is not rigorous and it is not clear how.it would be applicable to circumferential cracks.
6..
The end conditions and plastic instability model indicated on the plot of normalized burst pressure versus normalized half crack length need explanation.
- 7.
Provide a tabulated summary of all the primary to secondary leakage history to date (including those leak rates below the Technical Specification Limit) going back to before the 1974 tube leak.
- 8.
Provide a tabulation of the total population of eddy current indication deleted during the current outage giving the depth magnitude in steps of 10% -Of wall thickness and the tube location and elevation of indication along the tube.
- 9.
Provide a steam generator tube map for this inspection, for all indic~tion~
detected, noting removed, and previously plugged tubes.
- 10.
Provide a discussion of the differences in the September 1983 11 In Generator 11 and the 110ut of Generator 11 ECT Measureme.nts on B&W Tubes Nos. 16, 18, 63, 65, 85, and 97.
(Reference to Table in 11 Failure Analysis 11 hand out).
- 11.
With respect to non-leaking tubes reported to have 100% through wall pene.tration such as B&W Nos. 72 and 63, explain how these findin*gs are consistant with leak-before-break and how high a leakage rate one would expect under postulated accident conditions.
- 12.
Provide the fabrication history of the steam generator tubes with respect to the 90° bends in the U-bend region.
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Provide the following:
- 13.
Thermalmechanical history of the steam generator tubes before and after fabrication of the steam generators.
- 14.
Location and distribution of the degraded steam generator tubes.
- 15.
Determination of causative agent(s) and the damage scenario.
- 16.
Laboratory tests which substantiate the proposed damage scenario and corrosion mechanism(s).
- 17.
Metallurgical examination results and the steam generator tube thermal-mechanical histo~ which demonstrate the cracking at the 90-degree bends was IGA and not IGSCC.
- 18.
Inspection results or other information which show that the remainder of the secondary system does not suffer the same type of degradation observed on the steam generator tubes.
- 19.
Test results or analysis which provide reasonable assurance that the steam
- generator tube degradation have been stopped, the cracks were arrested, the contaminant(s) were removed.
- 20.
Procedures and administrative controls which will b~ implemented to prevent reintroduction of contaminant(s).