ML20214S473
| ML20214S473 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 09/18/1986 |
| From: | Miosi A COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 2129K, NUDOCS 8609300001 | |
| Download: ML20214S473 (14) | |
Text
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} Commonwealth Edison 72 V!est Adams Street. Chicago, llhnois
_-,2 Address Reply to: Post Office BoTT6T Chicago, tilinois 60690 - 0767 September 18, 1986 Mr. Harold R. Denton U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulatory Washington, DC. 20555
~
Subject:
Braidwood Station Unit 1 Preservice Inspection (PSI) Program Revisions and Clarifications NRC Docket No. 50-456 References (a):
August 8 ', 1906 A.D. Miosi letter to H.R. Denton (b):
July 31, 1986 A.D. Miosi letter to H.R. Denton (c):
June 17, 1985 A.D. Miosi letter to H.R. Denton
Dear Mr. Denton:
Enclosed in this letter is additional information required to complete your review of the Preservice Inspection (PSI) Program for Braidwood Station Unit 1 as discussed with members of your staff and your contractor EG&G Idaho.
Additionally, a commitment has been made to perform an augmented exam to be included in the Unit 1 ISI Program.
The attachment includes a summary of changes to the Braidwood' PSI Program Notes and Relief Requests.
The majority of the changes are clarifications to the relief requests already submitted to the NRC.
A new relief request is included (INR-16) which is a result of a further understanding of note 2 as identified in our submittal per reference (b).
The basis for the augmented ISI exam results from a NRC concern which deals with integranular stress corrosion cracking in lines that contain stagnant borated water in Class 2 piping in the RHR, ECCS, and Containment Heat Removal Systems.
Commonwealth Edison had exempted large bore (greater than 4") ASME Code Class 2 piping in the subject systems from the PSI program per 10CFR50 Section 50.55a (b)(2)(iv) " Pressure-retaining welds in ASME Code Class 2 piping (applies to Section XI Tables IWC-2520 or IWC-2520-1, Category C-F)".
This section also references the 1974 Edition and Addenda through the Summer 1975 Addenda of Section XI of the ASME 8609300001 860918 DR ADOCK 05000456 sh
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. Code which does not disallow the exemption of Class 2 piping in the RHR, ECCS, and Containment Heat Removal Systems.
As a result of this concern, Commonwealth Edison is committing to examine a random sampling of seven and one-half per cent.(7.5%) of the large bore (greater than 4") piping circumferential welds in the safety injection (SI), chemical and volume control (CV), and containment spray (CS) systems for Braidwood Unit 1.
The residual heat removal (RHR) system does not include any piping greater than 4" diameter, so it will not be included in the augmented exam.
The NRC agreed that CECO may perform the baseline exam for these welds during the first refueling outage.
Further examinations will be discussed in the Unit 1 ISI Program.
These welds will be examined over the ten year inspection interval as described in the ISI Program and will be tracked for the life of the plant.
Should you have any questions concerning this information please contact this office.
One signed original and fifteen copies of this letter and attachment are provided for your review.
Very truly yours, u
I M
A. D. Miosi Nuclear Licensing Administrator
/klj cc:
J.
Stevens B. Brown (EG&G Idaho) 2129K
s' Summary of Changes to Braidwood PSI Program Notes and Relief Requests 1.
Note 2 - Changed to include only the Class 2 welds which had limited volumetric examinations.
Class 1 welds which received limited volumetric exams were moved to new Relief Request' 1NR-16.
Percentage of weld not volumetrically examined added.
2.
Relief Request 1NR Figure numbers co'rrected references to
" volume" were changed to " surface".
3.
Relief Request 1NR Reference to Section XI exam category B-L-2 removed from code requirements section to clarify that the request applies only to valves and not pumps.
4.
Relief Request 1NR "Line number" changed to " component number".
5.* Relief Request 1NR Reference to VT-2 exams deleted from code requirements section because no relief is being requested from leakage /hydrotests.
6.* Relief Request 1NR-ll - Reference to head circumferential weld deleted from code requirements section because no relief is being requested for this weld.
7.* Relief Request 1NR Figure numbers corrected.
8.
Relief Request 1NR Clarification statement added to basis section that no volumetric exam was performed on any of the four (4) welds, and that one (1) of the four (4) welds received neither a surface nor volumetric exam.
9.
Relief Request 1NR Code item column added; number of items changed to seventeen (17); more specific information provided for inaccessible welds; statement on exam coverage added.
10.
Relief Request 1NR-15 -- Code item column added; more specific information provided for inaccessible welds, 11.
Relief Request 1NR Added - Class 1 welds which received limited volumetric exams (see Note 2).
- These are multi-page relief requests.
Only the page on which changes were made (in all cases page 1) are included in this submittal.
F Rsv. 1 NOTE 2 Volumetric examination coverage of the ASME,Section II Class 2 welds, listed below were limited because of component geometry or interference.
Percent of Weld Length Wald #
Lino #
Not Exemined Reason for Limited Exam 1MS-01-1 INS 01AD-32" 8%
Hozzle, gamma plug IMS-02-7 IMS01BD-30.25" 19%
'Jee, weldolets 1MS-04-7 IMS9'.BA-30.25" 24%
Weldolets, tee geometry IFW-01-1 1FWO o-16" 15%
Eranch connection, valve geometry 1FW-02-1 1FH96 A;.. - 16 "
15%
Branch connection, valve geometry IFW-04-29 1FWO3DC-16" 25%
Elbow inner radius, nozzle geometry ISI-04-28 ISIOSCA-8" 25%
Elbow inner radius, cable tray ISI-04-29 ISIOSCA-8" 8%
Elbow inner radius, adjacent pipe ISI-04-45 ISIOSCA-8" 8%
Obstructed by restraint ISI-12-22 ISIO4B-12" 8%
Gs.mma plug, valve geometry ISI-24BB-30 ISIO6BB-24" 33%
Obstructed by floor and wall 131-26-52 ISIOSCB-8" 16%
Elbow inner radii These welds received an ultrasonic examination consisting of axial and circumferential scans; however, because of the listed limitations, the axial scan from one side could not guarantee complete coverage of the required volume.
0322m(091086) 0885A
r-RELIEF REQUEST INR1 Rev. 2 1.
SYSTEM: Main Steam, Safety Injection, and Residual Heat Removal 2.
NUMBER OF ITEMS: 24 Line Number Weld Number INS 07AA-28" 1MS-04-25, IMS-04-26, IMS-04-27, IMS-04-28, IMS-04-29 INS 07AB-28" 1MS-06-43, IMS-06-44, 1MS-06-45, IMS-06-46, IMS-06-47 1MS07AC-28" 1MS-08-25, IMS-08-26, IMS-08-27, IMS-08-28, IMS-08-29 1MS07AD-28" 1MS-02-37, IMS-02-38, IMS-02-39, IMS-02-40, IMS-02-41 ISIO6BA-24" 1SI-24-23BA, ISI-24-23ABA ISIO6BB-24" 1SI-24-23BB, ISI-24-23ABB 3.
A.S.M.E. CODE CLASS: 2 4.
'A.S.M.E.
CODE SECTION XI REQUIREMENTS:
Examination Category C-F, Items C5.31 and C5.32, require a surface examination of the cres described in Figures IWC-2520-7 and 2520-9.
The required area is 100%
of each circumferential weld requiring examination and 2.St of the longitudinal weld at the intersecting circumferential weld. IWC-2200 states:
a.
All' examinations required by this article for those components initially selected for examination in accordance with Inspection Program A or Inspection Program B and not exempt from inservice examinations by IWC-1220 shall be completed prior to initial plant startup.
5.
BASIS FOR RELIEF: The above listed welds are inaccessible to surface examinations, due to the location of saddle plates over the pressure j
retaining welds.
6.
ALTERNATE TEST METHOD: A surface examination (liquid penetrant) and visual examination (leak test) will be performed on the saddle plate fillet welds in lieu of the required surface examinations for the pressure retaining welds listed above.
7.
JUSTIFICATION: Performing a surface and visual examination of the saddle plate fillet welds provides an acceptable level of structural integrity for system operation. Radiographs performed on the branch pipe circumferential welds verify its structural integrity at the time of construction. Therefore, an adequate level of plant operational g~
safety can be assured on these welds.
0322m(091086) 0885A
w-RELIEF REQUEST INR3 Rev. 2 1.
SYSTEM: Reactor Coolant, Reactor Coolant Pressurizer, Safety Injection, and Residual Heat Removal.
2.
NUMBER OF ITEMS:
41 3.
A.S.M.E. CODE CLASS:
1 4.
A.S.M.E. COC$j3ECTIONXIREQUIREMENTS: Examination Category, B-M-2, Item B12.40 requires a visual (VT-1) examination of the valve body internal surfaces on valves exceeding 4 inches nominal pipe size.
Examinations are limited to one valve within each group of valves that are of the same constructional design, e.g. globe, gate or check valve, manufacturing method and that are performing similar functions i
in the system e.g. containment isolation, system overpressure protection.
5.
BASIS FOR RELIEF: The requirement to disassemble an operable talve for the sole purpose of performing a visual (VT-1) of the internal
. pressure retaining boundary is impractical and not commensurate to the increased ss.fety achieved by this inspection. Class 1 valves are installed in their respective systems and many have completed functional testing. To disassemble these valves would provide a very small potential for increasing plant safety margins with a very disproportionate impact on expenditures of plant manpower and resources.
6.
ALTERNATE TEST METHOD:
The manufacturers test data will be used in lieu of a preservice visual examination (VT-1).
This includes documentation of examinations performed during fabrication and installation of the subject valves. The examinations performed may include volumetric, surface, and visual exams, as required by A.S.M.E.
Section II,. Material Specifications for Ferrous and Nonferrous materials.
7.
JUSTIFICATION: The integrity of the pressure retaining boundary of both carbon steel and stainless steel valve bodies has been i
excellent. Class 1 valve bodies cannot historically be linked to breaching of the pressure retaining boundary in plant systems. Class i
1 valves are subjected to numerous types of nondestructive testing and a rigorous quality assurance program during all stages'of fabrication, storage, and installation. These valves have been found acceptable by the Manufacturer, the A.S.M.E. Authorized Nuclear Inspector and Commonwe:11th Edison's Quality Assurance.
0322m(091086) 0885A
RELIEF REQUEST INR4 Rev. 2 1.
SYSTEM: Pressurizer Vessel and Steam Generator Vessel (Primary Side) 2.
NUMBER OF ITEMS:
14 Component Number Weld Number IRC01BA.
Primary Nozzles (2) 1RC01BB Primary Nozzles (2) 1RC01BC Primary Nozzles (2) 1RC01BD Primary Nozzles (2) 1RYOIS RY 1, 2, 3, 4 A, 4B, 4C 3.
A.S.M.E. CODE CLASS:
1 4.
A.S.M.E. CODE SECTION XI' REQUIREMENTS: Table IWB-2500-1, Examination Category B-D, Items B3.120 and B3.140 require volumetric examination of the regions described in Figure IWB-2500-7 for the inner radius of nozzles in the pressurizer and steam generators (primary side).
Subarticle IWB-2200, "Preservice Examination" states that:
a.
Examinations required by this article shall be completed prior to initial plant startup.
In addition. the preservice examinations shall be extended to include essentially 100% of the pressure retaining welds in all Class 1 components except in those components exempted from examination by IWB-1220 (a), (b), or (c).
5.
BASIS FOR RELIEF: The nozzles listed above all contain inherent geometric constraints and clad inner surfaces which limit the ability to perform meaningful volumetric examinations.
In an attempt to develop a technique to locate flaws in the nozzle. inner radii area, a mock-up was used with little sucess.
6.
ALTERNATE TEST METHOD:
All pressure retaining components were hydrostatically tested to the requirements of A.S.M.E.Section III.
7.
JUSTIFICATION:
In performing the hydrostatic test on all pressure retaining components, an adequate level of structural integrity is assured for plant operation.
0322m(091086) 0885A
RELIEF REQUEST INR-9 Rev. 3 1.
SYSTEM: Reactor Pressure Vesse'l 2.
NUMBER OF ITEMS:
4 Weld Number Finure Numbers RV-001 4,5,6 RV-002-1,2,3 RVCH-001 8, 9, 11 RVCH-002 7,
8.- 10 3.
ASME CODE CLASS:
1 4.
ASME CODE SECTION II REOUIREMENTS:
Table IWB-2500-1, Examination Category B-A, Pressure Retaining Welds in Reactor Vessel, Item Numbers Bl.11, Bl.21 Bl.30, and Bl.40 require volumetric examination of the regions described in Figures IWB-2500-1, 3, 4, and 5 respectfully for welds in the reactor pressure vessel.
Article IWB-2200 "Preservice Examination" states that:
a.
Examinations required by this Article shall be completed prior to initial plant startup. In addition, the preservice examinations shall be extended to include essentially 100% of the pressure retaining welds in all Class 1 components except those components exempted from examination by IWB-1220 (a), (b), and (c).
b.
Shop and field examinations may serve in lieu of on-site preservice examination provided:
1)
In the case of vessels only, the examination is performed after the hydrostatic test required by Section III has been completed; 2)
Such examinations are conducted under conditions and with equipment and techniques equivalent to those that are expected to be employed for subsequent inservice inspections; and 3)
The shop and field examination records are, or can be documented and, identified in a form consistent with those required in IWA-6000.
0322m(091086) 088SA
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1 Rsv. 1 RELIEF REQUEST INR-11 1.
SYSTEM: Chemical and Volume Control Excess Letdown Heat Exchanger 2.
NUMBER OF ITEMS:
1 Component Number Weld Number ICV 01AA ELHXC-03 3.
ASME CODE SECTION XI REQUIREMENTS: Table IWC-2500-1, Examination Category C-A, Item C1.10 requires volumetric examination of the regions described in Figure IWC-2520-1 for shell circumferential welds.
Mandatory Appendix III, Article III - 4000 requires examination for:
a.
Reflectors parallel to the weld seam.
The angle beam examination for reflectors parallel to the weld seam shall be performed by a full V path from one side or a one-half V path from two sides of the veld, where practicable.
b.
Reflectors transverse to the weld seam.
1)
The angle beam examination for reflectors transverse to the weld seam shall be performed on the weld crown on a single seam path to examine the weld root by one-half V path in two directions along the weld.
2)
For inservice examination, only those welds showing reportable preservice indications need be examined for transverse reflectors.
l S.
BASIS FOR RELIEF: Weld ELHXC-03 received radiographic examination to meet the requirements of ASME Section III.
These examinations could be used to meet the requirements of ASME Section XI.
However, we do not intend to use radiography as our inservice test method.
l 0322m(091086) 0885A l
F Riv. 2 RELIEF REQUEST INR-12 1.
SYSTEM:
Steam Generator Vessel (Secondary Side) Nozzles, Residual Heat Exchanger Nozzles 2.
NUMBER OF ITEMS: 10 Component Number Nozzle Number Restricted Exam 1RC01BA SGN-02,03 Inner radii IRC01BB SGN-02,03 Inner radii 1RC01BC SGN-02,03 Inner radii 1RC01BD SGN-02,03 Inner radii 1RH02AB RHXN-01,02 Inner radii and nozzle to vessel weld 3.
ASME CODE CLASS:
2 4.
ASME CODE SECTION II REOUIREMENTS: Table IWC-2500-1, Examination Category, C-B, Item C2.20 requires surface and volumetric examination of the areas described in figure IWC-2520-4 for nozzles in vessels over 1/2 inch in nominal thickness. This figure requires volumetric examination of the nozzle to vessel weld and, for pipe sizes over 12 inches, an examination of the nozzle inner radii.
5.
BASIS FOR RELIEF: The nozzles listed above contain inherent geometric constraints which limit the ability to perform meaningful ultrasonic examinations. The main steam nozzles (SGN-03's) have an internal multiple venturi type flow restrictor. This design does not have a nozzle inner i
radii as described in Figure IWC-2520-4.
This nozzle has seven individual inner radii, corresponding to each venturi, none of which could be examined by ultrasonic examination. The main feedwater nozzles (SGN-02's)
.also have an internal multiple venturi type flow restrictor but have a thermal sleeve in addition.
This design could not be examined due to the geometry of the nozzles internal design.
l i
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0322m(091086) 0885A l
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R;v. 2 RELIEF REQUEST INR-13 1.
SYSTEM: Reactor Coolant 2.
NUMBER OF ITEMS:
4 Line Number Weld Number Interferina Condition IRC21AD-8" 1RC-15-13 Permanent Restraint 1RYO1B-6" 1RC-16-1 Nozzle - Reducer ISIA4B-8" 1SI-02-35 Reducer - Valve ISIO4D-8" 13I-11-22 Reducer - Valve 3.
A.S.M.E. CODE CLASS:
1 4.
A.S.M.E. SECTION II REQUIREMENTS: Table IWB-2500-1, Examination Category B-J. Item B9.11 requires volumetric and surface examination of the areas described in Figure IWB-2500-8.
5.
BASIS FOR RELIEF: 1RC-15-13 is encased in a permanent whip restraint making preservice ultrasonic and surface examination impractical. The geometry of 1RC-16-1, 1SI-02-35 and 1SI-11-22 prohibit meaningful ultrasonic examination.
In all cases, 100% of the required ultrasonic volume was not examined.
6.
ALTERNATE TEST METHOD: A visual examination (VT-2, leak test) is proposed in lieu of the volumetric and surface examination requirements for 1RC-15-13.
A surface examination is proposed for IRC-16-1, 1SI-02-35 and ISI-11-22.
7.
JUSTIFICATION:
In performing a visual examination (leak test) on IRC-15-13 and surface examination on IRC-16-1, 1SI-02-35 and ISI-11-22, an acceptable level of structural integrity for system operation is l
provided. Austenitic stainless steel type 304 possesses a high degree of toughness. Crack propagation through this material is slow and leak testing is a viable method of identifying flaws prior to weld failure in this type of material.
In addition, acceptable surface and volumetric (radiography) examinations were performed on these welds during 7
l construction. Therefore, an adequate level of safety can be assured on i
this weld both now and during unit life.
l 0322m(091086) l 0885A 1
t
R;v. 3 RELIEF REQUEST INR 14 1.
SYSTEM: Main Steam, Feedwater, Safety Injection 2.
NUMBER OF ITEMS: 17 Line Number Weld Number Code Item Reason for Limited Exam 1MS13AD-8" 1MS-02-34 C5.21 Reducer-Valve 1MS13AA-8" 1MS-04-43 C5.21 Reducer-Valve INS 01AB-32.75" 1MS-05-7 C5.22 Permanent Restraint INS 13AB-8" 1MS-06-40 C5.21 Reducer-Valve INS 13AC-8" 1MS-08-43 C5.21 Reducer-Valve IFWO3DA-16" 1FW-02-08 C5.21 Inaccessible, inside missile wall-IFWO3DB-16" 1FW-03-11 C5.21 Permament Restraint ISIOSCD-8" 1SI-04-12 C5.21 Reducer-Valve ISIOSCA-8" 1SI-04-58 C5.21 Reducer-Valve ISIO6BA-24" ISI-24BA-33B C5.22 Inaccessible, permanent restraint ISIO6BA-24" ISI-24BA-34 C5.21 Reducer-Valve ISIO6BB-24" 1SI-24BB-28 C5.22 Inaccessible, obstructed by floor 1SIO6BB-24" 1SI-24BB-30B C5.22 Inaccessible, obstructed by floor ISIO6BB-24" 1SI-24BB-30C C5.22 Inaccessible, obstructed by floor ISIO6BB-24" 1SI-24BB-30A C5.21 Reducer-Valve ISIOSCC-8" 1SI-26-1 C5.21 Reducer-Valve ISIOSCB-8" 1SI-26-61 C5.21 Reducer-Valve 3.
A.S.M.E. CODE CLASS:
2 4.
A.S.M.E. SECTION II REOUIREMENTS: Table IWC-2500-1 Examination Category C-F, Items C5.21 and C5.22 require surface and volumetric examinations of the areas described in Figure IWC-2520-7.
5.
BASIS FOR RELIEF: The above listed welds cannot be examined by the ultrasonic method: in addition, welds IMS-05-7, 1FW-03-11, 1FW-02-8 and ISI-24BB-28 cannot be examined by the surface or ultrasonic method. In all cases, 100% of the required ultrasonic volume was not examined.
6.
ALTERNATE TEST METHOD:
The. structural integrity of these welds will l
be verified by periodic VT-2 (leakage) tests performed inservice.
7.
JUSTIFICATION: The requirements for Class 2 selection of welds for examination are based on a sample size of approximately 25% of the non high stress welds; therefore, other welds can be substituted for i
the inaccessible welds without comprising plant safety. All welds have received acceptable Section III examinations.
0322m(091086) 0885A i
ps*~
RIV. 3 RELIEF REOUEST INR-15 1.
SYSTEM: Residual Heat Removal and Feedwater 2.
NUMBER OF ITEMS: 4 Line Number Code Item Weld Number Interfering Condition 1RH02AA-8" C5.12 1RH-05-12B Inaccessible, inside missile wall 1RH02AA-8" C5.11 1RH-05-13 Inaccessible, inside missile wall IRH02AA-8" C5.12 1RH-05-13A Inaccessible, inside missile wall 1FWO87CB-6" C5.11 1FW-06-16 Inaccessible, inside missile wall 3.
A.S.M.E. CODE CLASS: 2 4.
A.S.M.E. SECTION XI REQUIREMENTS: Table IWC-2500-1 Examination Category C-F, Items C5.11 and C5.12 require surface examination of the areas described in Figure IWC-2520-7.
5.
BASIS FOR RELIEF: The above listed welds cannot be examined by the surface method.
6.
ALTERNATE TEST METHOD: The structural integrity of these welds will be. verified by periodic VT-2 (leakage) tests performed inservice.
7.
JUSTIFICATION: The requirements for Clasc 2 selection of welds for examination are base on a sample size of approximately 25%
of the non high stress welds; therefore, other welds can be substituted for the 3 inaccessible welds without compromising plant safety. All welds have received acceptable Section III examinations.
I 1
l 0322m(091086) 0885A
RIv. O RELIEF REQUEST INR-16 1.
SYSTEM: Reactor Coolant, Residual Heat Removal and Safety injection 2.
NUMBER OF ITEMS: 19 Percent of Weld Length Weld #
Line #
Not Examined Reason for Limited Exam 1RC-16-2 1RY01C-4" 16%
Elbow inner radius, reducer geometry 1RC-16-5 1RYO1B-6" 16%
Elbow innder radii 1RC-17-22 1RYO1AA-4" 16%
Elbow inner radius, reducer geometry IRC-32-1 1RYO3AA-6" 16%
Elbow inner radius, nozzle geometry 1RC-32-6 1RYO3BA-6" 16%
Elbow inner radius, flange geometry 1RC-32-7 1RYO3AB-6" 16%
Elbow inner radius, nozzle geometry 1RC-32-12 1RYO3BB-6" 16%
Elbow inner radius, flange geometry 1RC-32-13 1RYO3AC-6" 16%
Elbow inner radius, nozzle geometry 1RC-35-1 1RYO2A-6" 16%
Elbow inner radius, nozzle geometry 1RC-35-3 1RYO2A-6" 16%
Sockolet, both sides of weld 1RH-01-20 1RH01AB-12" 16%
Weldolets and valve geometry ISI-02-37 1RC35AA-6" 8%
Elbow inner radius, restraint ISI-02-42 1RC04AA-12" 8%
Tee geometry, gamma plug 13I-06-10 ISIOSDB-6" 16%
Cable tray ISI-09-4 ISIO9BC-10" 41%
Elbow inner radius, interfering pipe ISI-10-11 ISIO5DC-6" 8%
Electrical panel ISI-10-18A ISIO5DC-6" 8%
Restraint 13I-10-22 ISIOSDC-6" 16%
Elbow inner radius, tee geometry ISI-13-1 ISIO9BD-10" 8%
Sockolet, valve geometry 3.
ASME CODE CLASS:
1 4.
ASME SECTION XI REQUIREMENTS: Table IWB-2500-1, Examination Category B-J, Item B9.11 requires volumetric examination of the areas described in Figure IWB-2500-8 for essentially 100% of the weld length.
5.
BASIS FOR RELIEF: The above listed wolds have interfering conditions on
~
each side of the weld. These interferences can cause: poor coupling of the transducer, limited movement of-the transducer, redirecting of the sound beam and, in some cases, complete restriction of a particular scan.
These conditions sufficiently limit the axial scans so as to leave the l
listed percent of weld length uninspected.
6.
ALTERNATE TEST METHOD: All welde received the required Section XI surface examination in addition to the best effort ultrasonic examination.
l 7.
JUSTIFICATION:
The estimates of weld length not examined are extremely l
conservative and are actually a percent of weld length for which there is j
less confidence that the entire required weld volume was examined. Based on acceptable surface examinations, acceptable radiographic examinations and a best effort ultrasonic examination which inspected a majority of the l
weld length, an adequate level of structural integrity is assured.
l 0322m(091086) 0885A
,