ML18031B331
| ML18031B331 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Sequoyah |
| Issue date: | 09/03/1986 |
| From: | Bateman R, Lynskey R, Rose J TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML082401853 | List: |
| References | |
| WP-18-SQN, WP-18-SQN-R01, WP-18-SQN-R1, NUDOCS 8611120078 | |
| Download: ML18031B331 (7) | |
Text
WELDING PROJECT SPECIFIC EMPLOYEE CONCERN EVALUATION REPORT REPORT NUMBER:
WP-18-S N
Rl 08-26-86
SUBJECT:
EFFECTS OF LAMINATIONS ON WELD UALITY CONCERN CONSIDERED:
XX-85-098-001 PREPARED BY J 't OC, WP REVIEWED BY OC, WP REVIEWED BY QA, WP REVIEWED CEG-H, WELDING APPROVED BY PROGRAM MANAGER Revision 1 to this report incorporates comments made by the Senior Review Panel on 8/19/86.
8b11120078 8bii05 PDR ADOCN, 05000259
(
f PDR 00370
SPECIFIC EMPLOYEE CONCERN
SUMMARY
SHEET Report
Title:
EFFECTS OF LAMINATIONS ON WELD UALITY I.
CONCERNS CONSIDERED:
XX-85-098-001 II.
ISSUES XNVOLVED Laminations in pipe prevented making an acceptable weld in unit 2
condenser.
III.
STATEMENT OF CONCERN/ISSUE VALIDITY Validity:
Y X
N
, Substantiated:
Y IV.
EFFECT ON HARDWARE AND/OR PROGRAM i
None N
X V.
JUSTIFICATION Laminations in pipe are parallel to principal stress direction.
Welds terminate the lamination at the weld joint.
VI.
RECOMMENDATION AND/OR CORRECTXVE ACTION NEEDED None
~ V
/
VII.
REINSPECTION NEEDED:
Y N
X VIXI.
ISSUE CLOSURE By this report.
IX.
ATTACHMENT 1.
Text of Employee Concerns 00370 Page 1 of 1
SPECIFIC EMPLOYEE CONCERN Report
Title:
EFFECTS OF LAMINATIONS ON WELD UALITY I.
SCOPE OF EVALUATION This engineering evaluation relates to the following SQN specific concern:
XX-85-098-001 II.
ISSUES ADDRESSED BY CONCERNS The concern was analyzed to determine the issue voiced by the concerned individual.
This issue is as follows:
Laminations in pipe prevented making a good butt weld in unit 2 condenser, III.
CONCERN VALIDITYOR SUBSTANTIATION Condensers are nonsafety-related equipment built to manufacturers standard designs with custom specifications for fabrication and erection.
They generally specify ASME-type materials for construction, ASME welding procedure qualifications, and ASME welder performance qualifications.
Working pressures in condensers are characteristically very low (near atmospheric or slight vacuum) and the piping materials used in condenser construction do not need to be of the stringent quality that is used in high pressure piping service.
They are constructed of carbon steel materials which conform to either ASTM or ASME Section II material requirements.
Piping material for these applications is commonly A-53.
This material specification makes no mention of laminations being injurious defects.
A lamination is simply a discontinuity which is formed when blow holes resulting from the steel ingot casting process are not fully fused together in the rolling process for a particular product form.
These discontinities are located parallel to the direction of rolling of the product form and are usually at mid-depth of that product, although they may appear at other depths.
It is important to note that, they occur in a plane which is parallel to the product surfaces.
I Wrought products such as pipe and plate which are subsequently rolled and welded into pipe products, commonly have laminations due to the steel making process.
It is important to note that in piping applications where pipe is subject to internal pressures, laminations are of no consequence.
I I
IR1 I
00370 Page 1 of 2
WP-18-SQN, Rl ASME Section III which defines requirements for nuclear pressure piping in safety systems which are designed to much more stringent requirements than those used for condenser construction accepts laminations with qualifications.
ASME Section III, NB-5130 does not require weld repair of weld prep laminations which are one-inch and less in length.
Those which exceed one-inch in length are customarily ground back three eighths-inch and sealed-off by welding.
This sealing-off simply moves the lamination a distance from the weld joint which will prevent small porosity from appearing in the weld joint during subsequent welding.
This is done as a convenience for subsequent nondestructive testing, if required.
The net effect of welding over a lamination is simply to stop it and seal it off.
Welding over laminations will usually evolve a small amount of oxides or gases into the molten weld puddle. which will appear as porosity.
This porosity is bothersome to the welder, but if repaired, is acceptable.
I IR1 I
In summary, the issue voiced in this concern is valid but not substantiated.
It has been determined not to be detrimental for the following reasons:
l.
ASME Class 1 rules state that weld prep laminations one-inch and less in length are acceptable material conditions which do not require weld repair, Those greater than one-inch are allowed to be weld repaired after grinding to a specified depth.
2.
Condensers are constructed to requirements less stringent than ASME Class 1 which do not address laminations as injurious defects.
- 3. Laminations are commonly occurring discontinuities in wrought steel products and're not prohibited by material specifications.
4.
The effect of a lamination in a pipe subjected to internal pressure is of no concern.
- 5. Laminations pose no problem to weld joint integrity.
Based on the foregoing analysis, this concern is closed.
00370 Page 2 of 2
(EMPLOYEE CONCERNS)
Attachment 1
PAGE 1 of.1
~ 03/2'k/BB
%1:93:17 LQC STATUS RESP
-QTC-PPP CFR
~'1,"
!('i KEYWORDS:
WELDMENT QUALITY SPECIFIC INSP TC
-CONCERN PROBLEt1 ID NR XX-85-09B-001 WCt1HC X:
S Y:
C Z:
Y TECHNICAL CQMf1ENTARY:
ISSUE CONSIDERED:
LAf1INATION IN PIPE PREVENTED t1AKING A GOOD BUTT WELD IN THE UNIT TWO CONDENSER.
SEQUOYAH:
THERE WAS A LAf1INATED PIPE 12" QR 19" DIAMETER,CQi1ING QUT QF THE CONDENSER IN UNIT 2 TURBINE BUILDING, THE CRAFT COULD NOT GET A GOOD IIELD DUE TO LAt1INATION.
OCCURRED IN 1977.,DETAILS KNOWN TO QTC, WITHHELD DUE TO CONFIDENTIALITY.
CONST.
DEPARTMENT CONCERN. C/I HAS NQ ADDITIONAL INFORMATION.
'4