Severed Tubes in Operating Nuclear Steam Generators: Case Analysis — II

2003 ◽  
Author(s):  
M. K. Au-Yang
Keyword(s):  
Failure Mechanisms ◽  
Case Analysis ◽  
Root Cause Analysis ◽  
Steam Generators ◽  
Shell Side ◽  
Flow Induced Vibration ◽  
Cause Analysis ◽  
Root Cause ◽  
Eddy Current Inspection ◽  
Cast Doubt

During an eddy current inspection in April 2002, it was found that three tubes downstream of an out-of-service tube in a once-through nuclear steam generator (OTSG) had significant wear indications. Wear indications of these tubes has been recorded as early as 1995 and apparently has been progressing with time. A shell-side video inspection revealed that this tube was completely severed at the bottom tubesheet. This severed tube was discovered immediately after a tube in another OTSG of similar design was found to have severed at the top tubesheet. In the root-cause analysis of the other severed tube, the possibility of a similar tube failure due to flow-induced vibration at the bottom tubesheet was explicitly ruled out and corrective action was implemented based on this conclusion. This discovery cast doubt on the earlier analysis and raised concern on both steam generators. The purpose of this study is to carry out a root cause analysis of the failure of the second severed tube and show that even though the two failures appeared to be similar, the causes and failure mechanisms were different. The study also showed that what appeared to be an obvious fix turned out to be invalid upon more in-depth flow-induced vibration analysis.

Root Cause analysis of SG tube ODSCC indications within the tube sheets of NPP biblis unit A

2011 ◽  
pp. 78-86
Author(s):  
R. Kilian ◽  
J. Beck ◽  
H. Lang ◽  
V. Schneider ◽  
T. Schönherr ◽  
...  
Keyword(s):  
Root Cause Analysis ◽  
Cause Analysis ◽  
Root Cause

Rule Construction and its Execution for Root Cause Analysis

2012 ◽  
Vol 132 (10) ◽  
pp. 1689-1697
Author(s):  
Yutaka Kudo ◽  
Tomohiro Morimura ◽  
Kiminori Sugauchi ◽  
Tetsuya Masuishi ◽  
Norihisa Komoda
Keyword(s):  
Root Cause Analysis ◽  
Cause Analysis ◽  
Root Cause

Root Cause Analysis Techniques Using Picosecond Time Resolved LADA

2014 ◽  
Author(s):  
Dan Bodoh ◽  
Kent Erington ◽  
Kris Dickson ◽  
George Lange ◽  
Carey Wu ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Picosecond Laser ◽  
Root Cause Analysis ◽  
Fault Isolation ◽  
Time Resolved ◽  
Cause Analysis ◽  
Root Cause ◽  
Design And Manufacturing ◽  
Multiple Interactions ◽  
Established Technique

Abstract Laser-assisted device alteration (LADA) is an established technique used to identify critical speed paths in integrated circuits. LADA can reveal the physical location of a speed path, but not the timing of the speed path. This paper describes the root cause analysis benefits of 1064nm time resolved LADA (TR-LADA) with a picosecond laser. It shows several examples of how picosecond TR-LADA has complemented the existing fault isolation toolset and has allowed for quicker resolution of design and manufacturing issues. The paper explains how TR-LADA increases the LADA localization resolution by eliminating the well interaction, provides the timing of the event detected by LADA, indicates the propagation direction of the critical signals detected by LADA, allows the analyst to infer the logic values of the critical signals, and separates multiple interactions occurring at the same site for better understanding of the critical signals.

Root Cause Analysis for Pin Leakage

2016 ◽  
Author(s):  
Zhigang Song ◽  
Jochonia Nxumalo ◽  
Manuel Villalobos ◽  
Sweta Pendyala
Keyword(s):  
Failure Analysis ◽  
Root Cause Analysis ◽  
Advanced Technology ◽  
Process Step ◽  
Cause Analysis ◽  
Hard Mask ◽  
Technology Node ◽  
Root Cause ◽  
Tools And Techniques

Abstract Pin leakage continues to be on the list of top yield detractors for microelectronics devices. It is simply manifested as elevated current with one pin or several pins during pin continuity test. Although many techniques are capable to globally localize the fault of pin leakage, root cause analysis and identification for it are still very challenging with today’s advanced failure analysis tools and techniques. It is because pin leakage can be caused by any type of defect, at any layer in the device and at any process step. This paper presents a case study to demonstrate how to combine multiple techniques to accurately identify the root cause of a pin leakage issue for a device manufactured using advanced technology node. The root cause was identified as under-etch issue during P+ implantation hard mask opening for ESD protection diode, causing P+ implantation missing, which was responsible for the nearly ohmic type pin leakage.

Root Cause Analysis for the ATIRCM/CMWS Program

2010 ◽  
Author(s):  
Harold S. Balaban ◽  
Paul M. Kodzwa ◽  
Andrew S. Rehwinkel ◽  
Gregory A. Davis ◽  
Patricia F. Bronson
Keyword(s):  
Root Cause Analysis ◽  
Cause Analysis ◽  
Root Cause
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