|
---|
Category:GENERAL EXTERNAL TECHNICAL REPORTS
MONTHYEARML18066A4671999-03-31031 March 1999 Rev 0 to SIR-99-032, Flaw Tolerance & Leakage Evaluation Spent Fuel Pool Heat Exchanger E-53B Nozzle Palisades Nuclear Plant. ML20249C4951998-06-17017 June 1998 Rev 1 to EA-GEJ-98-01, Palisades Cycle 14 Disposition of Events Review ML18066A3411998-04-22022 April 1998 Rev 0 to EMF-98-013, Palisades Cycle 14:Disposition & Analysis of SRP Chapter 15 Events. ML20217C2741998-03-31031 March 1998 Independent Review - Is Consumers Energy Method (W Method) of Determining Palisades Nuclear Plant Best Estimate Fluence by Combining Transport Calculation & Dosimetry Measurements Technically Sound & Does It Meet Intent of Pts ML18065B1641998-02-0505 February 1998 Rev 0 to Regression Analysis for Containment Prestressing Sys at 25th Year Surveillance. ML20197J3891997-12-18018 December 1997 25th Year Physical Surveillance of Palisades Npp ML20217C2571997-12-16016 December 1997 Review of Neutron Fluence Data for Palisades Reactor Pressure Vessel ML18067A6351997-07-0909 July 1997 Excerpt from Ampacity Evaluation for Open Air Cable Trays W/Percent Fill Greater than 30% of Useable Cross Sectional Area. ML18067A6381997-07-0909 July 1997 Excerpt from Ampacity Evaluation for Continuously Energized Power Cables Routed Through Fire Stops, Revision 1 ML18067A6371997-07-0808 July 1997 Excerpt from Ampacity Evaluation for Duct Runs Containing Continuously Energized Power Cables, Revision 1 ML18067A6361997-06-26026 June 1997 Excerpt from Ampacity Evaluation for Continuously Energized Power Cables in Open Air Conduits, Revision 1 ML18066A8581997-01-31031 January 1997 Rev 2 to C-PAL-96-1063-01, Operability Assessment for Transient Conditions at Palisades Nuclear Plant in Response to GL 96-06. ML18065B0471996-07-12012 July 1996 TR on Use of Mcbend Code for Calculation of Neutron Fluences in PVs of Lwrs. ML18065A7571996-05-22022 May 1996 Rev 1 to IPEEE Rept, Per GL 88-20 ML20108C1671996-04-0101 April 1996 Nonproprietary Version of Fluence Calculations for Palisades Plant ML18065A5971996-03-23023 March 1996 Evaluation of Effects of Fire on West Wall of Turbine Lube Oil Room Adjacent to Pipe Tunnel Between TB & FW Purity Bldg. ML18065A6011996-03-22022 March 1996 Evaluation of Effects of Fire on West Wall of CCW Pump Room (Fire Area 16). ML20100D7491996-01-18018 January 1996 Rev 0 to Evaluation of Effects of Fire on West Wall of TB Lube Oil Room Adjacent to Pipe Tunnel Between TB & FW Purity Bldg ML18065A4481995-12-14014 December 1995 Radiological Consequences for Palisades Max Hypothetical Accident & Loss of Coolant Accident. ML18064A8321995-06-30030 June 1995 IPE of External Events (Ipeee). ML20085H2801995-05-23023 May 1995 Security Investigation Rept ML18064A7801995-05-19019 May 1995 Rept of SQUG Assessment at Palisades Nuclear Plant for Resolution of USI A-46. ML20078P7021995-01-27027 January 1995 Investigative Rept ML18064A4121994-08-22022 August 1994 Pressure-Temp Curves & LTOP Setpoint Curve for Max Reactor Vessel Fluence of 2.192 X 10^19 Neutrons/cm^2. ML20070J8001994-07-15015 July 1994 Final Rept Containment Sump Check Valves Weld Overlay Repair Implementation Evaluation Palisades Nuclear Plant ML18059B0041994-04-0505 April 1994 Rev 1 to EDG Fuel Supply Sys Storage Tank Tornado Protection Overview of EDG Fuel Supply Sys, Incorporating CARB Comments of 940318 & 24 ML20064E5301994-03-0606 March 1994 Evaluation of Effectiveness of Code Case N-504-1 Repair for Proposed Root Causes for Containment Sump Suction Check Valves ML20064E4451994-03-0505 March 1994 Check Valve Leak Root Cause,Engineering Analysis & Repair/Replacement Options ML18059A5161993-10-31031 October 1993 Nonproprietary Exam...Sections of Pressurizer PORV Line Safe-End Failure from Palisades Nuclear Generating Station. ML20058P1361993-10-31031 October 1993 Crack Propagation Analysis for Circumferential Cracks in Alloy 600 Nozzle Safe-Ends ML18059A4821993-10-25025 October 1993 Evaluation of Potential Interference Between TE-0102 Nozzle & Thermowell. ML18059A4831993-10-25025 October 1993 Structural Evaluation for Machined Thermawell for TE-0101. ML20059D8811993-10-23023 October 1993 Justification of Weld Mods to Pressurizer Temperature Nozzles for TE-0101 & TE-0102 ML18059A4811993-10-22022 October 1993 Acceptability of Partial Severing of TE-0101 Nozzle. ML18059A4801993-10-19019 October 1993 Structural Analysis of Temperature Nozzle Weld Mods for Consumers Power Palisades Pressurizer. ML18059A4791993-10-15015 October 1993 Half Bead Welding for Mods to TE-0101 & TE-0102. ML18059A4221993-10-0707 October 1993 Pressurizer Safe End Crack Engineering Analysis & Root Cause Evaluation. ML18059A3751993-08-31031 August 1993 Rev 1 to Palisades Cycle 11:Disposition & Analysis of SRP Chapter 15 Events. ML18059B0191993-07-31031 July 1993 Detailed Site Study,Berrien County,Mi, Final Rept ML18064A4271993-06-30030 June 1993 Wind Tunnel Predictions of Control Room Intake Concentrations from Three Sources of Radioactive Materials at Palisades Nuclear Power Plant, (CPP-Project 93-0907) ML18058B8661993-05-13013 May 1993 Resolution of Anchor Bolt Design Issues. ML18058B3911992-12-21021 December 1992 Cycle 11:Disposition & Analysis of Standard Review Plan Chapter 15 Events. ML18058B4281992-11-30030 November 1992 Vols 1,2 & 3 of Palisades Nuclear Plant Ipe. ML18058A5391992-06-16016 June 1992 Twentieth Yr Physical Surveillance of Palisades Nuclear Plant. ML20086P8551991-12-0909 December 1991 Criticality Safety Analysis for Palisades Spent Fuel Storage Pool NUS Racks ML20086P8571991-12-0909 December 1991 Criticality Safety Analysis for Palisades New Fuel Storage Array ML18057B3521991-10-31031 October 1991 Large Break Loca/Eccs Analysis W/Increased Radial Peaking & Reduced ECCS Flow. ML18057A8591991-03-31031 March 1991 Benchmarking & Validation of In-House DOT Calculation Methodology. ML20081K7741990-08-14014 August 1990 Incore Detector Algorithm (Pidal) Analysis of Quadrant Power Tilt Uncertainties ML18057A2611990-06-11011 June 1990 Simulator Certification Submittal. 1999-03-31
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML18066A6901999-11-0101 November 1999 Rev 5 to Palisades Nuclear Plant Colr. ML18066A6761999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for Palisades Nuclear Plant ML18066A6271999-09-0202 September 1999 LER 98-011-01:on 981217,inadequate Lube Oil Collection Sys for Primary Coolant Pumps Was Noted.Caused by Design Change Not Containing Appropriate Level of Rigor.Exemption from 10CFR50,App R Was Requested.With 990902 Ltr ML18066A6351999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Palisades Nuclear Plant ML18066A6771999-08-31031 August 1999 Operating Data Rept Page of MOR for Aug 1999 for Palisades Nuclear Plant ML18066A6221999-08-20020 August 1999 LER 99-002-00:on 990722,TS Surveillance Was Not Completed within Specified Frequency.Caused by Failure to Incorporate Revised Frequency Into Surveillance Schedule in Timely Manner.Verified Implementation.With 990820 Ltr ML18066A6061999-07-31031 July 1999 Monthly Operating Rept for July 1999 for Palisades Nuclear Plant.With 990803 Ltr ML18066A5201999-06-30030 June 1999 Monthly Operating Rept for June 1999 for Palisades Nuclear Plant.With 990702 Ltr ML18066A4841999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Palisades Nuclear Plant.With 990603 Ltr ML18066A6371999-04-30030 April 1999 Revised Monthly Operating Rept for Apr 1999 for Palisades Nuclear Plant ML18068A5941999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for Palisades Nuclear Plant.With 990503 Ltr ML18066A4161999-04-0101 April 1999 Rev 4 to COLR, for Palisades Nuclear Plant ML18066A4501999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for Palisades Nuclear Plant.With 990402 Ltr ML18066A4671999-03-31031 March 1999 Rev 0 to SIR-99-032, Flaw Tolerance & Leakage Evaluation Spent Fuel Pool Heat Exchanger E-53B Nozzle Palisades Nuclear Plant. ML18068A5351999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for Palisades Nuclear Plant.With 990302 Ltr ML18066A3931999-01-31031 January 1999 Monthly Operating Rept for Jan 1999 for Palisades Nuclear Plant.With 990202 Ltr ML18066A3781999-01-20020 January 1999 LER 98-013-00:on 981222,safeguards Transfer Tap Changer Failure Caused Inadvertant DG Start.Caused by Failed Motor Contactor.Contactor Was Replaced.With 990120 Ltr ML20206F6131998-12-31031 December 1998 1998 Consumers Energy Co Annual Rept. with ML18066A3651998-12-31031 December 1998 Monthly Operating Rept for Dec 1998 for Palisades Nuclear Plant.With 990105 Ltr ML18066A3421998-11-30030 November 1998 Monthly Operating Rept for Nov 1998 for Palisades Nuclear Plant.With 981202 Ltr ML18066A3301998-11-11011 November 1998 Part 21 Rept Re Potential Safety Hazard Associated with Wrist Pin Assemblies for FM-Alco 251 Engines at Palisades Nuclear Power Plant.Caused by Insufficient Friction Fit Between Pin & Sleeve.Supplier of Pin Will No Longer Be Used ML18068A4921998-10-31031 October 1998 Monthly Operating Rept for Oct 1998 for Palisades Nuclear Plant.With 981103 Ltr ML18068A4851998-10-29029 October 1998 LER 97-011-01:on 971012,starting of Primary Coolant Pump with SG Temps Greater than Cold Leg Temps Occurred.Caused by Inadequate Procedures & Operator Decision.Sop Used for Starting Primary Coolant Pump Enhanced ML18066A3181998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for Palisades Nuclear Plant ML18066A2901998-08-31031 August 1998 Monthly Operating Rept for Aug 1998 for Palisades Nuclear Power Plant.With 980903 Ltr ML18066A3191998-08-31031 August 1998 Revised Monthly Operating Rept Data for Aug 1998 for Palisades Nuclear Plant ML18066A2831998-08-18018 August 1998 LER 98-010-00:on 980721,reactor Manually Tripped.Caused by Failure of Coupling Which Drives Feedwater Pump Main Lube Oil Pump.Main Lube Oil Pump Coupling & Associated Components Replaced & Satisfactorily Tested ML18066A2771998-08-13013 August 1998 Part 21 Rept Re Deficiency in CE Current Screening Methodology for Determining Limiting Fuel Assembly for Detailed PWR thermal-hydraulic Sa.Evaluations Were Performed for Affected Plants to Determine Effect of Deficiency ML20237E0301998-07-31031 July 1998 ISI Rept 3-3 ML18066A2701998-07-31031 July 1998 Monthly Operating Rept for July 1998 for Palisades Nuclear Plant.W/980803 Ltr ML18066A2311998-06-30030 June 1998 Monthly Operating Rept for June 1998 for Palisades Nuclear Plant ML18066A2261998-06-30030 June 1998 LER 98-009-00:on 980531,small Pinhole Leak Found on One of Welds,During Leak Test Following Replacement of Pcs Sample Isolation Valves.Caused by Welder Error.Leaking Welds Repaired ML18066A3061998-06-18018 June 1998 SG Tube Inservice Insp. ML20249C4951998-06-17017 June 1998 Rev 1 to EA-GEJ-98-01, Palisades Cycle 14 Disposition of Events Review ML18066A1781998-06-0909 June 1998 LER 98-008-00:on 980511,noted That Procedure Did Not Fully Satisfy Requirement to Test High Startup Rate Trip Function. Caused by Misunderstanding of Testing Requirements.Revised TS Surveillance Test Procedure & Reviewed Other Procedures ML18066A1711998-06-0101 June 1998 Part 21 Rept Re Impact of RELAP4 Excessive Variability on Palisades Large Break LOCA ECCS Results.Change in PCT Between Cycle 13 & Cycle 14 Does Not Constitute Significant Change Per 10CFR50.46 ML18066A1741998-05-31031 May 1998 Monthly Operating Rept for May 1998 for Palisades Nuclear Plant.W/980601 Ltr ML18066A2321998-05-31031 May 1998 Revised MOR for May 1998 for Palisades Nuclear Plant ML18068A4701998-05-31031 May 1998 Annual Rept of Changes in ECCS Models Per 10CFR50.46. ML18065B2451998-05-13013 May 1998 LER 98-007-00:on 980413,HPIS Sys Was Noted Inoperable During TS Surveillance Test.Caused by Performance of Flawed Procedure.Operators & Engineers Will Be Trained to Improve Operational Decision Making Through Resources & Knowledge ML18066A2331998-04-30030 April 1998 Revised MOR for Apr 1998 for Palisades Nuclear Plant ML18068A3461998-04-30030 April 1998 Monthly Operating Rept for Apr 1998 for Palisades Nuclear Plant.W/980501 Ltr ML18066A3411998-04-22022 April 1998 Rev 0 to EMF-98-013, Palisades Cycle 14:Disposition & Analysis of SRP Chapter 15 Events. ML18065B2071998-03-31031 March 1998 Monthly Operating Rept for Mar 1998 for Palisades Nuclear Plant.W/980403 Ltr ML20217C2741998-03-31031 March 1998 Independent Review - Is Consumers Energy Method (W Method) of Determining Palisades Nuclear Plant Best Estimate Fluence by Combining Transport Calculation & Dosimetry Measurements Technically Sound & Does It Meet Intent of Pts ML18066A2341998-03-31031 March 1998 Revised MOR for Mar 1998 for Palisades Nuclear Plant ML18068A3041998-02-28028 February 1998 Monthly Operating Rept for Feb 1998 for Palisades Nuclear Plant.W/980302 Ltr ML18066A2351998-02-28028 February 1998 Revised MOR for Feb 1998 for Palisades Nuclear Plant ML18065B1641998-02-0505 February 1998 Rev 0 to Regression Analysis for Containment Prestressing Sys at 25th Year Surveillance. ML18067A8211998-01-31031 January 1998 Monthly Operating Rept for Jan 1998 for Palisades Nuclear Plant.W/980203 Ltr 1999-09-30
[Table view] |
Text
,
i .
O O Decniber 12, 1971 CONTRACT 2966A CONSUMERS POWER CO.
PALISADES PLANf CIOSURE HEAD STUDS INTRODUCTION It had become necessary to remove the vessel head. Upon starting to remove the studs it was noted that a rusting condition was pre,sent, which was apparently caused by spillage of borated water and possibly a dichromate solution. Be-cause of the rusted condition, C-E considered it desirable to closely examine the studs to determine whether or not there was any damage even though it was considered unlikely. C-E arranged for the removed studs to be sent to the stud manufacturer for clean up and careful examination by "magnaglo", and to have C-E personnel present.
In refurbishing the studs the manufacturer reground the threads, and machined the shank using a carbide tool removing 0.010 to 0.015 inches from the stud shank diameter. Upon "magnaglo" testing, 20 of the total of 54 studs exhibited several linear indications. All indications were in the shank portion of the studs and were in a circumferential orientation. Liquid penetrant testing was also per-formed at the manufacturer and no indications were found in this orientation.
No indications were present in the threaded portion of the studs. The indications variedinlengthuptoamaximumof1-3/4 inch. These studs are 7 inches diameter and 56 inches long. They are made to requirements of C-E Specifications as follows:
Material and Ultrasonic Testing C-E Purchase Spec. No. P0H16(c)
A540 Grade B24 Class 3 "Magnaglo" Testing (both before and after threading)
C-E M&P Spec. No. 2.4.2.5(a) and AS M E138-63 Phosphate Coating C-E M&P Spec. No. 4.4.4.l(a)
On Friday, December 10, 1971, two of the refurbished studs were received for metallurgical investigation. One of the two was representative of the most pronounced "magnaglo" indications (#44), and the other stud was representative of the average "magnaglo" indication appearance (#43). The stud #44 exhibited 13 indications, mostly in the central section of the shank. These varied in circumferentiallengthfrom1/8inchto1-3/4 inch.
8307080422 711126 PDR ADOCK 05000255 G PDR r a
e.
i -
O O CONCLUSIONS
- 1. Indications were disclosed by "magnaglo" testing. These were cir-cumferentially oriented.
- 2. Examination of the indication areas by metallography (both etched and un-i etched), at the original surface and to depths at which the "magnaglo" l indication disappeared, revealed that no " defect" was present at any stage.
1 4 3. The "magnaglo" indications are present in a right hand thread pitch orientation of somewhat steeper helix angle than that of the present surface finish. The indications result from slight differences in material magnetic permeability
- properties probably caused by slight variations in surface cold work induced
- in earlier machining steps and possibly intensified by heating incurred in phosphate coating and in service.
.i
) 4 "Magnaglo" indications of virtually identical appearance were present in a stud of the same size from another contract manufactured with the same procedure, and subjected to a hydrostatic test use but not service. The j "magnaglo" test was also performed after removal of the phosphate coating.
i'
- 5. The extensive examination confirms that, without any doubt, the subject j
stude are satisfactory for use, 1
i Stud Manufacture t
' C-E purchased the material for these studs as 7-1/2 inch diameter round bars on C-E Purchase Order No. 46-60144. The vendor is believed to have straightened the bar stock on a " bulldozer" (press) and not to have used a rotary straightener.
The bars were assigned C-E Code No. D-3816. C-E subcontracted the machining on C-E Purchase Order No. 46 62329 Machining and "magnaglo" testing were per-i formed and the studs returned to Chattanooga where they were phosphate coated 4
on C-E Purchase Order No. 47 47464 After phosphate coating no further "magnaglo" testing was performed.
1 The stud manufacturer ground the threads, and machined the shank using a carbide tool. The rough cut on the shank was to a depth of 0.040" to 0.050" per side using a 0.015" to 0.018" feed. The finish cut on the shank was with a carbide tcol with 1/32" nose radius at 200 feet per minute with 0.009,'to 0.010" feed to j a depth of 0.010" to 0.015" per side. The cut was in a right: hand thread direction with the stud chucked at the top end and a steady rest near the bottom end threads.
! Stud Use
' The studs have "seen" a total of four prestressing cycles - one at C-E on hydro-static test, and three at the job site. The studs had reached a temperature in service of approximately 500 F. On each of these cycles a lubricant was used.
This lubricant is " Super-Moly". It contains an " inhibitor". It is molybdenum disuphide with mineral oil base.
A
l E (3 O t*
. G Q)
Other Studs
( .
Two studs of identical design available in Chattanooga from another contract were
! examined simultaneously with the subject studs. These studs were of identical l manufactire except the phosphate coating was performed by a different vendor.
Each of these studs had been used on a shop hydrostatic test. One was "magnaglo" tested with the phosphate coating left on and one after removal of the phosphate coating.
METALLURGICAL INVESTIGATION Immediately upon "magnaglo" examination by experienced personnel at C-E, it was recognized that the indications disclosed were some form of non-relevant indication and did not constitute a " defect". Examinat. ion procedure by "magnaglo" was performed with equipment and technique duplicating that used by the stud manufacturer and with identical results, as confirmed by an employee of Chattanooga Nuclear Quality Control Department who was present at the testing at the stud manufacturer and at the testing of the returned pieces at C-E laboratory.
Procedures and examinations to confirm this conclusion are given below.
~
After +he "magnaglo" testing results obtained at the stud manufacturer were duplicated on equipment at Metallurgical Research and Development Laboratory in Chattanooga, a series of metallographic examinations were made directly on the stud surfaces at the location of "magnaglo" indications. Examination was performed after a minimum amount of metal was removed from the surface (0.001" to 0.003")
and after probe grinding to various depths up to 0.050" which partly or completely removed the "magnaglo" indications. Probe grinding was controlled to expose completely the entire subsurface zone associated with "magnaglo" indications to direct metallographic viewing. Quality of the metallographic finish and metallographic etch were fully comparable to conventional laboratory preparation of small specimens. Viewing was with a binocular laboratory microscope of superior optical performance (Leitz ND) at nagnification of 50X to 1000X. The visual examination through the microscope was fully comparable to laboratory bench metallography in all respects and no compromise was necessary regarding thoroughness of examination. For these reasons, it was not necessary to destructively section any of the studs to obtain unequivocal results and no further information is to be gained by destructive sectioning.
Stud Number 4 , Palisades Probe grinding 0.013" deep was performed on stud #W by the stud manufacturer in an attempt to establish the depth of the condition causing the "magnaglo" indications. As the rough surface appeared to obscure the "magnaglo" results, this spot was carefully polished with 600 grit to avoid more than 0.001 additional metal removal and to obtain a better surface for testing. Afterwards this spot was examined repeatedly at the same test conditions used at the stud manufacturer and at higher and lower field strength.
t .
J
i Ui O
!ETAILURGICAL IINESTIGATION (Cont'd.)
O "Magnaglo" indications were not present down in the 0.013" deep excavation but could be seen at the edge of the excavation. This excavation was 31-5/8" below top end. l An area showing indications, 32" from the top end of stud #44, was polished metallographically to a depth of 0.003" below the original machined surface.
"Magnaglo" indication was still present in this area after 0.003" metal removal.
, This area was examined up to 1000X as polished and after etching with nital.
No indications of defects were found.
One circumferential indication about 32 inches from the top end of stud #44 was examined metallographically by grinding two dimples, about 0.020" deep, at the two ends of the indication until the "magnaglo" indications were no longer present, leaving the center portion unground. The dimples and the unground portion were then polished metallographically, after marking the unground portion of the in-dication with a center punch. After polishing, the unground portion and the slope
- of the dimple were examined at magnifications up to 1000X, simulating the j examination of a cross section through the indication. No defects or other abnormalities were detected, either in the as-polished or etched condition.
j Stud Number 43, Palisades 4
Areas showing circumferential indications in stud #43 were examined in a similar manner. Two adjacent indications, about an inch long were ground and polished so as to leave an unground portion. After polishing to a depth of 0.013" and 0.029", the indications disappeared at the bottom of the dimples. The unground j
portion was punch marked to identify the indication line, then polished lightl,y (about 0.001"). Microscopic examination revealed no defects. The slope of the dimples was also examined microscopically after metallographic polishing into
'j the area showing no "magnaglo" indications. This slope area, which was in effect a cross section through the zone between indications and absence of indications, showed no evidence of defects, i
Other Studs Two studs for another contract, which were in'the shop and had not been in service, were also examined in a similar manner. One stud, #52, showed "magnaglo" indications on the as-phosphated surface. Examination of the I surface before polishing showed circumferential marking. On polishing, the visual evidence of the indication disappeared, although some of the phosphate conversion coating was still present in spots. These spots disappeared after i
i l 4-J
f 1
?i ' ;.
. 1 poliching to a depth of 0.003", and no defacts or abnormalitiss vsre visible.
Upon re-examination by "magnaglo", however, the indication was still present.
Another stud from the same contract, #53, was also examined after removing the coating by polishing in a lathe with emery paper. This stud also showed scattered circumferentisl indications by "magnaglo" techniques. No further metallographic examination was performed on this stud.
Simwnary Close examination revealed that all of the circumferentially oriented "magnaglo" indications are at a slight pitch angle at a slightly steeper helix angle than that of the present surface finish. This is probably the orientation of the pitch helix used in a cut previous to the final machining cut. The stud manufacturer reported use of a right hand pitch during their machining operation.
The "magnaglo" indications are also at a right hand pitch angle. The sensitive "n:agnaglo" test is undoubtedly revealing indications resulting from magnetic premeability variations probably caused by slight variations in surface cold work induced by machining and possibly intensified by heating incurred in phosphate coating and in service. Such cold work may have been introduced by another fabrication operation not presently identified.
Results of the examination described above have conclusively verified the judgment that circumferential "magnaglo" indications on these studs are "non-relevant" and are not defect indications.
Technical evaluation was performed prior to the removal, during refurbishing, of the 0.010" to 0.015" stock from the shank cf the studs. The analyais indicated an acceptable change. The final Stress Report will be supplemented to include this change.
l I
i l
1 J