ML20042B389
| ML20042B389 | |
| Person / Time | |
|---|---|
| Site: | Millstone, Indian Point  |
| Issue date: | 06/15/1967 |
| From: | Reinmuth G US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| Shared Package | |
| ML20042B374 | List: |
| References | |
| 50-245-67-02, 50-245-67-2, 50-247-67-02, 50-247-67-2, NUDOCS 8203250271 | |
| Download: ML20042B389 (28) | |
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U. S. ATOMIC ENERGY CODMISSION HEADQUARTERS DIVISION OF COMPLIANCE June 15, 1967 CO REPORT No. 247/67-2 CO REPORT NO. 245/67-2
Title:
CONSOLIDATED EDISON CO. (INDIAN POINT 2)
LICENSE NO. CPPR-21 CONNECTICUT LIGHT & POWER CO. (MILLSTONE POINT)
LICENSE NO. CPPR-20 Date of it: May 24-26, 1967
.2). M.
M By:
G. W. Reinmuth, Reactor Inspector (Program Standards)
SUDWARY The Combustion Engineering plant in Chattanooga, Tennessee, was visited to review the progress of reactor pressure vessel fabrication for the Consolidated Edison Co., Indian Point 2 and the Connecticut Light & Power Co., Millstone Point reactors.
Fabrication of both vessels has proceeded with relatively few diffi-culties. On-time delivery may be expected if current progress is main-tained.
A bottom dome place for the Indian Point 2 vessel was broken during an early stage of fabrication while in a relatively brittle condition. The broken plate was scrapped and replaced in the as-built vessel.
l On the Millstone vessel, CE is utilizing exceptionally heavy temporary l
support fixtures in the shell sections to assure dimensional control.
Equivalent efforts have not been observed at the other vendors. While dimensional control on the shell sections has been excellent, offset dimensions of the orange peel sections of the upper head were marginal.
CE indicated code compliance had been achieved by following code allowable corrective procedures.
A record review of these vessels disclosed that the material used was within specifications,that welding procedures had been properly qualified and that the usual testing methods had been employed. Based upon this information and the statements of the personnel concerned, it may be con-cluded that the vessels will meet the present code requirements when completed.
(continued) 8203250271 670627 PDR ADOCK 05000247 G
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DETAILS I.
Scope of Visi_t_
The Combustion Engineering (CE) plant in Chattanooga, Tennessee, was visited to review the progress of pressure vessels being manufactured for the Indian Point 2 and Millstone reactors.
Mr. Richard Lofy of Parameter, Inc., consultant to the Division of Compliance 1/ accompanied the inspector on the visit. The principal persons contacted during the visit were:
J. Visnich, Manager, Nuclear Products, CE J. S. Meek, Project Engineer, CE E. S. Proctor, Manager, Quality Control, CE E. Maclin, Chief, Quality Control, CE L. C. Northard, Manager, Manufacturing Engineering, CE Jack Grob, Engineering, Consolidated Edison Co.
J. Lavelle, Purchasing, Consolidated Edison Co.
E. J. Dadson, U. S. Testing Company, Inc.
L. Forse, Design Engineer, Westinghouse H. L. Russo, Project Manager, Indian Point 2, Westinghouse R. Bremer, Manager, Quality Control, Westinghouse C. J. Herbsz, Purchasing Agent, Westinghouse J. White, Contracts, Westinghouse II.
Results of Visit A.
General Information Work is in progress on the vessels listed below. The percent completion numbers are approximations made by the inspector based upon observation of the vessel pieces in the shop.
Facility Complation Consolidated Edison Co. (Indian Point 2) 70%
Connecticut Light & Power Co. (Millstone) 60%
Carolina Power & Light Co. (Robinson 2) 40%
Consumers Power Co. (Palisades) 30%
In addition to these vessels, CE has commitments from G-E and Westinghouse for 17 other vessels. Including their own reactor contracts, CE currently has a firm backlog of 25 vessels.
(continued) 1/ A report of this visit prepared by Mr. Lofy is attached as Attachment III.
3-Results of Visit (continued)
CE also is fabricating the two steam generators for the Palisades reactor. While the shells are of lower design pressure, the complexity of manufacture is approximately equal to that of the pressure vessel. A re-view of procedures used for these units will be made during a later visit.
B.
Process Considerations A lengthy discussion was held with CE and Westinghouse repre-sentatives to talk about current procedures and the experience in fabricating the Indian Point 2 vessel. The following information was obtained:
1.
Plate Material CE normally buys all plate material in the non quenched and tempered condition. Upgrading of the material is performed by CE after hot forming by quenching and tempering. Jtace these operations change the properties of the material, CE routinely conducts impact and tensile tests on each plate after these operations. These tests are in addition to those performed by the steel supplier. Chemical tests are con-ducted on a sampling basis only by CE.
From these series of tests, a good record is available for evaluating material properties. Typical results for the Indian Point 2 vessel are listed in Attachment I and for the Millstone vessel in Attachment II.
Both Charpy and drop weight impact tests are conducted on Westinghouse and G-E vessels although the requirements differ.
On Westinghouse vessels, the NDT is determined by drop weight, then the foot-pound energy required to break the standard Charpy specimens is measured at that temperature.
Westinghouse minimum foot-pound energy requirements at NDT were not stated.
G-E on the other hand requires a minimum energy level of 30 foot-pounds at specified minimum temper-atures; + 10 F for the high stress regions and + 40 F for the remainder of the vessel; + 40 F is then considered the NDT of the vessel. The impact data reviewed indicated a relatively consistent quality whether taken from'a PWR or a BWR plate.
CE recently moved their Charpy testing apparatus to a new building. Following the moving, the machine was recalibrated and satisfactorily checked with standard test samples from the Watertown Arsenal. Westinghouse personnel stated they now require calibration against standard samples within specific time ILmits as a condition of each vessel contract.
(continued)
Results of Visit (continued)
Ultrasonic tests (UT) of plate in the flat condition are routinely performed by the steel supplier. Test require-ments and acceptance standards are those specified by Code Case 1338-2, Alternate II.
If defect areas are detected and determined to be repairable, the repairs are performed by CE according to code requirements.
Upon receipt of the plate, CE conducts a second UT test in the flat condition utilizing both the longitudinal and shear wave technique. This test is a 100% volumetric test and serves to verify mill test results.
In addition, a third UT test after forming is currently required by G-E.
The acceptance criterion for this third test has also been changed from the loss of back reflection standard to a flat bottom hole test block calibration. A fee of $72,000 was paid by G-E for this test on the Millstone vessel.
On subsequent G-E vessels, the test will be a standard specification require-ment.
- 2. Welds Test samples to verify material properties.in the weld metal and in the heat affected zones for each vessel are not rou-einely taken. In lieu of such tests and in accordance with code, welding procedure qualification is relied upon to give assurance of proper weld quality.
In the case of CE where the same procedures are used for extensive periods of time, a single set of test results must be relied upon to assure the weld quality of several vessels.
7Recent code revisions (1966 Winter Agenda) provided that weld procedures could be qualified according to specific weld wire and flux lot combinations. CE has employed this method to requalify all welding procedures. The new procedures are being used in fabricating both the Indian Point 2 and Millstone vessels. Representative test results are given in Att.:chment I.
These revisions, however, still do not provide ter.t data i
for each vessel since the principal fabricators buy weld wire and flux in earload quantities. These supplies may last through the fabrication cycle of several vessels.
- 3. Claddinn CE has experienced no significant problems with its 3-wire cladding process. Observations of the work indicate a uni-form thickness and a surface smoothness requiring only a minimum of preparation for conducting UT tests.
Chemical sampling is performed periodically as a process control check.
(continued)
9
, Results of Visit (continued) 4.
Records CE was questioned concerning the extent of records which would be supplied to the owner of the vessel. Following is a partial list quoted:
a.
An as-built drawing of the vessel with detailed dimensions.
b.
Copies of welding procedures used.
c.
Mill and CE material test reports including lot iden-tification.
d.
A log of the final heat treatment of the vessel, e.
Impact test data.
f.
Weld repair locations.
CE stated they have retained all data generated to date on all vessels built and that they will continue to do so.
Their policy is to retain this information for the design life of the vessel. CE further stated that a vessel owner would be provided copies or access to this information upon request at any time.
C.
Indian Point 2 Vessel Fabrication The discussions previously mentioned centered around the fabrication history of the Indian Point 2 vessel. In addition, further information was obtained by a record review including an examination of the deviation file.
Noteworthy is the action of the Consolidated Edison Co., in engaging the services of E. J. Dadson of the U. S. Testing Company, Inc., to audit the performance of vendors in supplying components for the Indian Point 2 plant.
Mr. Dadson has been visiting CE approximately monthly since fabrication of the vessel was started.
Fabrication of the Indian Point 2 vessel has proceeded to assembly of the vessel into three major pieces - the bottom dome section; the upper two shell courses, including nozzles, and upper vessel flange; and the top closure head. Pilot holes for the rod drives had been drilled in the top closure head. The major work remaining is final sizing and machining of the rod open-ings for installation of the rod sleeves, final vessel assembly and machining and final stress relief.
On-time delivery (mid 1968) appears to be no problem based upon progress to date.
(continued)
. Results of Visit (continued)
With one exception, the fabrication of the Indian Point 2 vessel has proceeded with relatively few difficulties. The exception involved the breaking of a bottom done plate which was subsequently scrapped and replaced.
While all the circumstances of the breakage were not dis-closed, the principal conditions leading to the breskage were as follows:
1.
The plate had been hot formed at a temperature between 1650-1700"F.
2.
Breakage occurred before quench and temper while in a relatively brittle condition.
Mr. Forse estimated the NDT at this time to be greater than room temperature.
3.
A sharp notch where the break started had been placed in the plate by the test sample cut-out piece.
4.
According to Westinghouse, the plate had been jarred while propped up on blocks.
Since this place was replaced, the importance to the Indian Point 2 vessel, as-built, is marginal. However, additional details will be obtained during the next CE visit. The principal corrective action taken to prevent recurrence is to assure that notches are not created at this stage by cutting operations.
l Typical examples of deviations experienced during the fabrication I
of the Indian Point 2 vessel are as follows :
1.
Eccentricity was noted in some of the small nozzles furnished by a sub-supplier. They were returned.
2.
Chemical analysis on the cladding in a local area was out of specification. The area was removed and the cladding replaced.
3.
The control rod housing flange edges were machined excassively.
Following an evaluation of the situation by the engineering department and upon the concurrence of Westinghouse, the con-dition was accepted without repair.
4.
The pilot hole for stud hole No. 10 in the vessel flange was offset. The condition was noted before final machining and threading. A detailed procedure was prepared to assure that (continued)
,s
. Results of Visit (continued) subsequent work would not require a major repair. The procedure included additional magnetic particle and dye penetrant inspection and step-by-step instructions for final machining operations. As a result of the special precautions takcn, the final threaded hole was found acceptable.
5.
The replacement done plate was found to have an edge crack after quench and temper. Most of the crack was removed by trimming to final size; however, a weld re-pair to a depth of approximately 5 inches was required to remove all evidences of the crack. The repeir was found acceptable following ultrasonic and radiographic testing.
In the presence of Mr. Dadson, radiographs for the circumferential seam weld between the upper and middle shell courses and four of the six nozzles were reviewed. The radiographs had been taken by the CE linear accelerator and all showed the code required penetrameter image. No flaws were observed. Four or five imperfections (code acceptable) had been marked on the prints with a wax pencil. Upon removal of the marks, a considerable effort was needed to relocate the areas.
Mr. Dadson stated this was indicative of the scrutiny routinely given the radiographs.
In his opinion, CE's radiography was of high quality.
D.
Millstone Vessel Fabrication A partial record review of this vessel disclosed the information itemized in Attachment II.
Mr. Lofy reviewed the deviation file and covers its contents in his report (attached as Attachment III).
Fabrication of this vessel is also proceeding satisfactorily. At the time of the visit, the upper two shell courses had been assembled and welding of the upper shell flange to this piece was in progress. The two i
l bottom shells had also been assembled including the large steam and primary l
water inlet nozzles. The G-E site representative said that no difficulties l
had been experienced in the nozzle welds. The remaining pieces (bottom and top domes and upper flange) were on the bay floor in varying stages of I
completion. Delivery by the scheduled June 1968 date does not appear to be a problem at this time.
Of significance on this vessel is the method CE is taking to achieve and maintain dimensional control of the shell sections. Four heavy internal support rings with heavy cross bracing were installed in each of (continued)
I
Results of Visit (continued) the two assembled shell section pieces to assure that distortion of the shells does not occur during fabrication. These will be left in place until after final stress relief. As a result of these efforts, out-of-roundness has been maintained to within 5/8".
Equal results, however, have not been achieved on the upper dome. Up to 1/2" offset between " orange peel" sections has occurred during welding. Since the code requirement limits offset to 3/8",
analysis of the stresses in the region was required (Section III, N-414).
Mr. Meek stated this analysis had been performed and that the condition was acceptable as is.
In accordance with code procedure, the offset areas had been " flared in" with weld metal.
(See R. Lofy's report, Attachment III, for a more detailed discussion.)
E.
Exit Intervim No formal exit interview was held; however, Mr. Porse of Westinghouse and Mr. Proctor of CE were contacted by telephone after the visit to clarify certain points on the broken plate (Section C).
Additional information on this item and others raised by Mr. Lofy of Parameter, Inc., will be obtained during the next inspection.
Attachments:
Attachments I, II, III
ATTACHMENT I Indian Point 2 Material Test Data I.
Plate Material (SA 302-B Modified)
Chemical Test Results C
Mn P
S Si Ni Mo Mill Test Reports-Value
.22.23 1.27-1.37
.009.013.020.025
.21.26 43.50
.45.49 Ranges (%)
CE Test Results-same
.21.25 1.32-1.41
.013.012.018.020
.25.28 47.50 47.49 material Tensile Test Results (Typical)
Ultimate (psi)
Yield (psi)
Elongation Plate B-2001-1 92,100-93,500 73,900 257.
B-2001-2 85,600-91,000 65,300 27%
B-2001-3 96,500-97,700 71,100 26%
CE Impact and Lukens Ultrasonic Test Data Plate No.
NUI Charpy Fix at NDT UT Results*
Drop Weight (Average - 3 samples)
B-2001-1) Upper
-10 F 13.5 ft-lbs 2k" x 2k" indication
-2) Shell
-10 F 9.5 ft-lbs 2 indications ~ 2k" x 2k" 0
-3) Course
-10 F 20.5 ft-lbs No indications (NI)
B-2002-1) Mid
-20 F 11.0 ft-lbs 15 indications-max.2\\" x 1" g
-2) Shell
-30 F 14.0 ft-lbs 8 indications-max.2 " x 1 3/4"
-3) Course
-10 F 20.0 ft-lbs NI B-2003-1) Lower
-20 F 23.5 ft-lbs NI
-2) Shell
-20 F 43.5 ft-lbs NI B-2006-1) Top
+10 F 42.0 ft-lbs NI
-2) Peel 0F 23.0 ft-lbs NI B-2007 Top Dome
+10 F 35.0 ft-lbs NI B-2008-1) Bottom
-20 F 24.0 ft-lbs NI
-2) Peel
-10 F 29.5 ft-lbs NI C-2001-1 Replace-
-30 F 15.5 ft-lbs NI ment bottom dome plate
- Defect less than 3" diameter code accectable.
4 Attachment I (continued) I'I. Bolting Material (4340) - Bar Stock Timken Roller Bearing Co.
Chemical Test Results C
Mn P
S Si Cr Nu Mo Cu
.40
.81
.010
.008
.27
.87.90 1.92
.38
.10 Ultimate Strength (psi) 161,000 - 164,000 Yield Strength 138,000 - 152,000 III. Top Head Flange Forging (A-508-64 Material)
U. S. Steel Chemical Test Results C
Mn P
S Si Ni Cr Mo Co V
.20.23
.60.64
.006.008
.010.013
.26.30
.70.78
.34.42
.58.61
.01
.04 Charpy Test Results Sample @ 0"F
+10 F 45-25-51 (ft-lbs)
Sample @ 180 F
+10 F 28-45-40 (ft-lbs)
Tensile Test Results Yield Value 50,000 psi Ultimate 80,000 psi No indication of defects from ultrasonic and magnetic particle tests.
IV. Submerged Arc Automatic Welding Procedure Test Data Conditions of Test i
A.
10 " thick test plate B.
Weld wire diameter for seam material - 3/16"
'C.
Back groove weld wire diameter - ("
D.
Preheat temperature - 250 F to 500 F Impact Test Results (Charpy)
Base Metal @ 10 F 42-38-42 ft-lbs Weld Metal @ 10 F 90-80-81 ft-lbs 0
Heat Affected Zone Metal @ 10 F 93-89-106 ft-lbs
ATTACHMENT II Millstone Material Test Data Plate Material (SA302-B Modified) Mill Test Reports - Typical Values Chemical Properties C
Mn P
S Si Ni Mo
.20.25 1.26-1.39
.006.012
.018.032
.23.29
.46.52
.46.50 Tensile Properties Ultimate 81,000 - 93,750 psi Yield 61,300 - 76,200 psi Impact Test Results Plate No.
Test Temp. (OF)
Charpy Values (ft-lbs)
Thickness G-2001-lR) Lower
+10 47-51-37 6"
-3 ) Shell
+40 61-61-66 6)"
-5 ) Course
+40 44-57-59 6i" G-2001-2 ) Upper
+10 33-51-27 6\\"
-4R) Shell
+10 45-50-57 6Y'
-6 ) Course
+10 30-36-41 6"
G-2002-4) Lower
+10 59-46-42 5"
-5)
Intermediate
+40 53-57-57 5%"
-6)
Shell Course
+10 38-53-50 5\\"
G-2002-1)
Upper
+10 30-34-32 Si"
- 2)
Intermediate
+10 42-37-38 5!"
-3)
Shell Course
+ 10 62-60-55 Sk" G-2008-1 Closure head dome
+10 72-77-56 4 1/8" l
l G-2007-1)
Closure head
+10 61-64-70 4 1/6" j
- 2) Torus plates
+10 80-84-86 4 1/8" I
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Page i of17 i
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REPORT OF VISIT TO I
d COM130STION ENGINEERING Cl!ATTANOOGA, TENN.
l May 25-26, 1967 4
No. DC-7 June 5, 1967 8
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I Richard A. Lofy, P.E.
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PARAMiiTER, Inc.
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Consulting F.ngineers l
Elm Grove, Wisconsin j
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Page 2 of 17 i
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I Distribution Copics:
AEC Regulatory Organization Division of Compliance L.
Kornblith - G. W. Reinmuth (2)
AEC Contracts Division Chicago Operations Office F. Mattmueller - R. A. Anderson (1)
PARAMETER, Inc.
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J. J. Chyle (l) e a
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Page 3 of 17 I nt roduc ti.on :
The writer accompanied Mr. G. W.
Reinmuth, AEC Division of Compliance on a visit to the Combustion Engineering facility at Chattanooga, Tennessee, on 'tay 25-26, 1967 The purpose of the trip was to inspect in-process vessel fabrication and review process records f or uni ts a
advanced stages in the shop.
Two specific vesseln were of immediate in teres t a t this time.
The first, a P n::
Westinghouse vessel for the Consolidated Edison Indian Point Sta tion, Unit No.
2, and the second, a General Electric BWR vessel for the Millstone facility.
On Thursday, May 25th, the entire day w.is devoted to inspection of major components and review of recorIs for the Indian Point Sta ti on.
Contacts for these activi-ties were:
Combustion Enoineerino, Inc.
Mr. J. Visnich, Manager, Nuc l ear Pro <luctr.
Mr. R. Proctor, Manager, Quality Control Mr. J. S. Meek, Project Engineer Mr. E. Macklin, Quality Control Mr. L. Northard, Process Engineering Westinohouse Elect ric Corpora tion Mr.
R. Brommer, Quality Cont rol Mr. L.
Porse
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Page 4 of 17 9
Consolidated Edison Mr. E. Dadson, Manager, Non-Destructive Tecting Division, United States Testing Company (Representing Con-Ed)
(Other Westinghouse and Consolidated Edison personnel were present at the plant, but did not participate in the detailed review sessions)
Friday, May 26th was devoted to reviewing materials data and process records for the General Electric Millstone reactor vessel.
Contacts were:
General Electric Mr. C. C. Roof, Quality Control Representative Combustion Enqineering Mr. R. Proctor, Manager, Quality Control Mr. L. Northard, Process Engineering Discussion:
I WESTINGIIOUSE PWR VESSEL for CONSOLIDATED ED[ SON INDIAN POINT STATION The first order of busines' 03 Tnursday, May 25th, was a tour of Combustion Engin c.r!
5s shop to view major compo-3 nents of the Indian Point vessel in process.
These were:
1 The Closure head - The dome section to which the head flange has been joined.
!! ales f or attach-ment of control rod housings were rough bored
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Page 5 of 17 and the head was resting inverted in a machine fixture pending further work.
2 The vessel's upper shell sectipn - the eight inlet and outlet ports with integral support pads have been attached.
Radiographic inspec-tion of four ports has been completed and passed -
the remaining four were in process of film evaluation.
3.
The lower shell section - comple ted and await-ing joining to the upper shell.
Instrumentation holes in the lower head have been preliminarily drilled.
Overall appearance of all components was good.
Conbustion indicated that for this unit, it was now their intention to I
stress relieve the entire unit after completion of the assembly girth seam.
l Af tdr the shop inspection, a general diccussion of the l
j Indian Point vessel fabrication history was held with both i
l Combustion and Westinghouse personnel participating.
I In discussing plate quality, it was indicated that this job l
j had an exceptionally good history.
Their were few ultra-
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Page 6 of 17 sonic test rejections and plate edge inspection by magna-flux revealed a minimum of defects.
Good quality all through the 10" thick upper shell was observed in boring nocale openings.
In answer to the writer's question, Combustion Engineering indicated that they would prepare an as-built drawing of the vessel showing individual plate locations and all wcid seams.
From this, it would be possible to identify each heat of plate, direction of rolling and ingot top side.
It should also be possible to some extent to correlate the plate defects to their location in the vessel from the plates original ultrasonic inspection report.
In receiv-ing plates, C.E. or their vendor prepares a map of repor t-able defects for the entire plate.
Ilowever, when the plate is cut for fabrication the exact location of these defects relative to a plate edge (or weld seam) is los t.
No specific attempt is made to go back after fabrication and check known defects for growth or propagation.
While the methods and information to monitor plate defect.a are in l
l existence, this procedure is not followed nor is it required by code.
In future upgrading of quality controls, considera-l l
tion might be given to implementing such a system to allow l
l as-built records of defects in the actual vessel.
A l
(
further cer'tification could then be provided that the known l
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Page 7 of 17 conditions of the vessel did not deteriorate during hydro-test.
Mr. Proctor explained the method of test sampling plates for NDT and materials properties by removal of a corner corresponding to the top end of the billet.
Charpy test equipment has been recently calibrated to Watertown Arsenal Standards and uniform results are being achieved.
Mr. Forse indicated that all of the plate had an NDT below 10 F. by dropweight test.
In discussion of plate repairs, Combustion Engineering indicated that they were now keeping records of all plate repairs requiring radiography.
This information could also be summarized and recorded for surveillance purposes as indicated above.
As an aside, Mr. L. Porse indicated that a substantial amount of plate material, with its history was being set aside on all Westinghouse jobs as part of the PVRC program.
If cofrelated carefully with individual vessels, this material should provide valuable secondary data should questions a-rise during vessel life.
It will also be useful in applying fracture mechanics methods now being developed In a discussion of weld procedure qualifications, C.E.
\\
indicated that they have generally run full thickness test 5
r ~s Page 8 of 17 plates although this is not required by the code.
After qualification of the ASME test plate, the control is over the welding process, the flux and the wire.
In clarifi-cation of Mr. Reinmuth's question, Mr. L. Northard of C.E.
indicated that he thought there was nothing to be gained in testing vessel welds.
If actual vessel weld properties are to be monitored, consideration should be given to preparation of sanples from a run-off tab attached to a typical longitudinal scam.
Thus actual properties in the parent metal, weld, and 11A2 of the most highly stressed joint could be recorded.
In answer to Mr. Reinmuth's question regarding NDT shift in the core area, Mr. Porse indicated that he did not consider this to be a problem in large IMR's.
IIe indica-ted that where flux might control in small diameter reactors, flow controls in large units and an excess of water shielding was available.
He further pointed out that there were no structural discontinuities in the core arep.
Cladding was discussed briefly; C.E.
indicating that they have no problems in this area.
Their internal control is on the Ni-Cr ratio of the deposited material.
Their customer specification controls only iron.
Mr. Northard indicatedkhattheirstringent internal controls were necessary to insure integrity during the most severe
1 3
N, j
Page 9 of 17 operation the cladding would see - that is the stress re-lieve cycle.
Record keeping and controls were discussed next.
C.E.
indicated that 'they would submit to Westinghouse the following:
Drawings, including an as-built dimensional profile, material locations, and X-ray locations.
Procedures - fabrication and process Mill Reports
" Blanket" Certifications of NOT inspections A log of the final Heat Treatnent C.E.
keeps all records for a period of five years (as required by ASNE Code) at which time they can be trans-ferred to the customer if so desired.
Inquiries by the writer regarding fit-up and deviation from Code requirements form did not raise any problems.
App,arently, using their procedure of machining shells inside 1007o and outside (full or partially) allowed t
better than code fit-up in all cases.
I t was ineil.cated that the Westinghouse requirements for roundness (1/2G) in the core area were much tighter than Code.
To date there.have been no deviations which have required analytical disposition.
Mechanical deviations have been g
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Page LO of 17 limited to minor tolerance variations.
Combustion Engineering's practice of shell machining (ID & OD) to meet Code requirements for fit-up again raiscu the question of-its effect on net shell strength.
It is well known that heavy plates can have a laminar composition.
If an out-of-round plate is rounded by machining.a relative-ly heavy layer of material of its periphery, does the possibility of partially losing the strength of a layer of material exist?
(See comments of Appendix to our Neport DCL-3)
While this effect might be minor, possibly the analyst should somehow " discount" his materials properties for this effect.
At Combustion, there was some evidence of cleanup problems and wall thinning requiring weld repair even with their generous stock allowances.
During the aftornoon of the 25th, Mr. Reinmuth, Mr. Dadson of United States Testing (Representing Con-Ed) and the writer reviewed materials records.
Good records on plate
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and forging, chemical and mechanid properties, Ultra-sonic j
t es't records, and NDT data were availabic.
Mil Duct'ility l
Temp,by drop weight had been established for each plate with an accompanying Charpy transition curve on which the Charpy V-notch "fix" for the NDT could be identified.
It was our observation f rom the curves that plate material was generally better than 30 f t.
lbs at 40 F.
thus meeting t
specifications.
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Page 11 of 17 Ultrasonic, inspection records included maps of repirtable defects.
As noted earlier, correlation of whole plate defects to detail parts later f abricated from the I lates was difficult.
The material records review indicated that one pla e being fabricated for the loaer dished head of the vessel (the dollar section) had actually cracked in half "duri.g pre-heat for flame cutting" and was scrapped.
Another plate was similarily processed and developed an edge cra k which was repaired before further fabrication into the vrssel assembly.
It is not too clear what the plate cond' tion was when the cracks were discovered.
They had bec:t formed, but the order of subsequent heat treatment and/or quench and temper operations was not established.
Combustion indica-ted that they had remedied the difficulty in revising their flame cutting process.
It is the writer's feeling that a gross stress pattern in the plate must have existed to cause this type of failure, and that the contributing factors should be further evaluated.
Certainly the process ccquence should be studied.
Beyond that, the plato history, rolling direction, mechanical properties, forming tempera-ture, post forming stress relieve, and other variables should be checked in arriving at a technical explanation for the problem.
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Page L2 of 17 A review of naterials properties and NDT data for the flange forgings (A508-64 material) showed the sound material and good ductility expected of this material.
On Friday morni~ng,,May 26th, the rejection reporti for the Indian Point vessel were reviewed primarily by Mr. Rcinauth with the writer assisting.
The only significant 1:jection record obccrved by the writer was in reference to the cracking of the dollar plate section described ab( /c.
II GENERAL ELECTRIC BWR VESSEL for MILLSTOMG STNi:M On Friday, May 26th, another tour of the shop was lade to view major components of the Millstone vessel in 2thrication.
Their status was:
1.
The top head
" orange peel" sectors had )een welded into the torus assembly.
The top lollar sector or flange have not yet been attacl :d.
2 The upper shell assembly - the girth scar for attachment of the vessel flanga was being com-g pleted.
The flange has been preliminari1 bored for the closure studs.
3.
The lower shell assembly - the control rod pattern in the bottom head was being final bored ior instal-lation of the housing %
(The housings again get
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Page L3 of 17 bored for final position and sine af ter i.1stalla-tion)
The support skirt has been welded in place.
It was noted that fit-up of seans between the sogn :nts foraing the knuckle section for the closure head v ts q u ite poor.
Visually the typical offset appeared to be tbout 1/2" or more.
While the offsets were blended with tapers, they would cppear to be up to or exceed Code allov. bles for fitup (prior to welding without blending) for the hickness of material in this area.
Poor results were attri uted to non-rigidity of the fixturing.
The ausenbly was f xtured by internal bracing and placed on a positioner for submerged arc welding.
After placement on the positioner, a,parently little i' done to re-align the work.
It should be possible to remedy this condition in the future by strictor in-pro-Cess Controls.
e The ASME code allows blending of offsets of this t: 2e with-out any explicit deviation.
We have maintained th: t the offset tolerances should be maintained at fit-up, 1 lus precluding the possibility of an as-welded oliset tayond code.
It is our opinion that this Code offset shou..d be the line of demarcation, beyond which the analyst should make a disposition of the deviatico.
This would be a good case on which to test such an interpretation.
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Page 4 of 17 Upon completion of the shop tour, the materials re ords for the Millstone vessel were reviewed in the office of General Electric Quality Control Representative, M. C.
C. Roof.
Particular attention was paid to Nil Duc ility Temperature data for the shells.
The upper shell ourse (adjacent to the flange) was noted to just make 30 Ft.
lbs. V-notch Charpy impact at 100F.
This satisfic. G. E.
specifications for material in this section where :old bolt-up stresses are experienced.
The other plates for inter-mediate shell course thickness all met 30 f t.
lbs at 400F, with some margin.
The 4-1/8" material for tto closure dome section had a vide margin at 10 F.
(.11 plates had approximately 1" of extra stock thickne :s for subsequent machining operations:
upper shell - 6
./2",
intermediate shells 1/2", upper dome 1/8" 3-1/4" required), lower head torus 1/4", and lower he.d dollar section at 7-1/4".)
Ultrasonic records for the plate were reviewed alo g with the materials physical test data.
Again, it was d fficult to establish a correlation between the defects in he raw plate, and the vessel component subsequently f abric ated from it.
Later in the day, the Combustion Egnineering files of
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.5 of 17 rejection and deviation noticos for the bullstone vessel nero reviewed.
It was noted from the rejection records and oreviously revicwed UT reports that C. E. had received a numb r of very bad plates for this contract.
Soma of theco ore beyond repair, were cut in half and sent bach to t,e mill.
From the inspection records it was noted that the neridion-al wolds on the upper torus section for the lower head had an extro2cly bad history of X-ray defects and repa.:.rs.
ab This sub-component had been weld by the "Up-John" or "hard uay" process and poor welder performance throughout certain seams and at specific levels of seams was evident.
Using this process, the torus is set up on a surfacc pla e along the tangent line - dome end up.
Run-off strips ar. welded to the edge of the entire length of the seam The welder starts at the floor and welds through the full plate thickness from one end of the sean to the otherFit-up by phis method seemed to be better than using the positioner as described earlier for the top head torus.
Poor words two were attributable to causes by C.E; inenperienced welders 3
working in some sections and secondly, the tendency of the tack welded run-off strip to pull away from the seem ed ge.
This later condition has been remedied by use of ft 11 le i
ngth
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o Page 3 6 of 17 fillet weldc.
There was a history of numerous edge repair s resulting from magnetic particle inspection on plates for thu Millotone vescel.
Repairs had been made by grindi..g back coaling the laminations, and rowelding according t i, code nothods.
Shell sub-assemblies for the Millstone veccel were very well fixtured by the.use of round-out rings and br;cing during fabrication and machining operations Mr. Ioof indicated that all shells were round within S/G".
From the records, a history of chcIl out-of-roundu:cc was noted from the fact that weld patching had been pc formed on shells to maintain thickness.
It appears that iven.
with the 1" thick machining allowance, C.E. has core trouble keeping their shello round in the cub-acccr bly stage.
This was also in evidence in observing othsr chells being machined on C.E.'s vertical boring mill at the* time.
On Friday P.M., a meeting was held with Mr. L. Norihard of C.E. in which wold processes for claddingand weld quali-fication procedures were discussed In summary; it is suggested that the following prollem
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.7 of 17 areas be followed up to obtain technical resolutio.u 1.
Cracking associated with forming and flamo cutting on the heavy dollar plate ocction ; as used on the Indian Point vessel.
2 Offsets beyond code fit-up allowances on he torus for the Millstone closure head.
3.
Overall effect of " scalping" plates in sh:11 courses by inside and outsido diameter ma.hining.
A general recommendation is made to cutablish a sy tem for correlation of material's defect and repair histor; to the final as-built condition of the vessel.
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Cf; m J. w R.
A. Lory, P.
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PARAMETER, Inc.
Consulting Engineers Elm Grove, Wisconsin
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