Root cause investigation of the inadvertent failure of unit 2 forced draft fan motor and the corrective actions implemented

2011 ◽  
Author(s):  
John K. Amoo-Otoo
Keyword(s):  
Root Cause ◽  
Forced Draft ◽  
Corrective Actions

Well Integrity Catastrophe Avoided Through Advanced Well Integrity and Reservoir Monitoring Analysis, a Case Study

2021 ◽  
Author(s):  
Mohamed Elyas ◽  
Sherif Aly ◽  
Uche Achinanya ◽  
Sergey Prosvirkin ◽  
Shayma AlSaffar ◽  
...  
Keyword(s):  
Geothermal Gradient ◽  
Root Cause ◽  
Well Integrity ◽  
Reservoir Monitoring ◽  
Precision Temperature ◽  
Zonal Isolation ◽  
Potential Failure ◽  
Corrective Actions ◽  
Thickness Measurements ◽  
Pulsed Neutron

Abstract Well integrity is one of the main challenges that are facing operators, finding the source of the well problem and isolating it before a catastrophic event occurs. This study demonstrates the power of integrating different reservoir monitoring and well integrity logs to evaluate well integrity, identify the underlying cause of the potential failure, and providing a potential corrective solution. Recently, some Injector/producer wells reported migration of injection fluids/gas into shallower sections, charging these formations and increasing the risk of compromised well integrity. Characterization of the well issues required integration of multi-detector pulsed-neutron, well integrity (multi finger caliper, multi-barrier corrosion, cement evaluation, and casing thickness measurements), high precision temperature logs and spectral noise logs. After data integration, detailed analysis was performed to specifically find the unique issues in each well and assess possible corrective actions. The integrated well integrity logs clearly showed different 9.625-inch and 13.375-inch casings leak points. The reservoir monitoring logs showed lateral and vertical gas and water movements across Wara, Tayarat, Rus, and Radhuma formations. Cement evaluation loges showed no primary cement behind the first barrier casing which was the root cause of the problem. Therefore, the proposed solution, was a cement squeeze. Post squeeze, re-logging occurred, validating zonal isolation and a return of a standard geothermal gradient across the Tayarat formation. Most importantly, the cement evaluation identified good bond from the squeeze point clear to surface, isolating all formations. All these wells were returned to service (injector/producer), daily annular pressure monitoring confirmed that no further pressure build up was seen. Kuwait Oil Company managed to avoid a catastrophic well integrity event on these wells and utilized the approach presented to take the proper corrective actions, and validate that the action taken resolved the initial well integrity issues. Consequently, the wells were returned to service, and the company avoided a costly high probability blowout.

Uncontained Failure of a U.S. Navy Rolls-Royce 250-KS4, Root Cause Investigation and Subsequent Corrective Actions

2012 ◽  
Author(s):  
John Viercinski ◽  
Matthew Hoffman ◽  
Ivan Pineiro ◽  
Dennis Russom
Keyword(s):  
Gas Turbine ◽  
Contributing Factors ◽  
Turbine Generator ◽  
Turbine Engine ◽  
Root Cause ◽  
Us Navy ◽  
The Future ◽  
Corrective Actions ◽  
Type Of Failure

In 2008, a US Navy DDG-51 Class destroyer experienced an uncontained failure of a Rolls Royce 250-KS4 turbine engine which serves as a starter for the Ship Service Gas Turbine Generator (SSGTG). This paper discusses the events that preceded the failure, the root cause and contributing factors. It also describes multiple corrective actions, including design improvements that have been implemented with the goal of preventing this type of failure in the future.

Corrosion Cause Analysis of Electric Feedwater Pump Motor Shaft in Nuclear Power Plants and Relevant Corrective Actions

2017 ◽  
Author(s):  
Che Yinhui ◽  
Guan Jianjun ◽  
Zu Shuai ◽  
Chen Qiang
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Economic Benefits ◽  
Motor Shaft ◽  
Cause Analysis ◽  
Root Cause ◽  
Feedwater Pump ◽  
Corrective Actions

Electric feedwater pump is an important feedwater equipment of nuclear power plants, and its reliability is directly related to the safe and steady operation of nuclear power plants and also economic benefits. In fact, corrosion of electric feedwater pump motor shaft occurs repeatedly, and even bearing shell in the motor can be burned out happen sometimes. This text sets out to analyze the cause of corrosion of electric feedwater pump motor shaft, identify the root cause, and further work out pertinent corrective actions based on the structure of the feedwater pump.

Semiconductor Wear Out at Nuclear Power Plants

2000 ◽  
Author(s):  
James B. Riddle
Keyword(s):  
Failure Analysis ◽  
Case Studies ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Light Output ◽  
Analysis Techniques ◽  
Root Cause ◽  
Corrective Actions ◽  
Control Circuits

Abstract This paper will examine semiconductor wear out at San Onofre Nuclear Generation Station (SONGS). The topics will include case studies, failure mechanisms, diagnostic techniques, failure analysis techniques and root cause corrective actions. Nuclear power plants are unique in that instrumentation and control circuits are continuously energized, are periodically tested, and have been in operation for greater than 25 years. Root cause evaluations at SONGS have identified numerous semiconductor failures due to wear out. Case studies include light output deterioration in opto-isolators, junction alloying failures of transistors and integrated circuits and parametric shifts in operational amplifiers. In most cases the devices do not fail catastrophically but degraded to the point of circuit level functional failure. Failure analysis techniques include circuit analysis, board level troubleshooting to identify the degraded components. Intermittent failures require power cycling, thermal cycling, and long term monitoring to identify the responsible components. Corrective actions for semiconductor wear out at SONGS include enhanced monitoring and proactive change out of identified part types.

Metal Slice Defect Induced Package Level Reliability Failure

2006 ◽  
Author(s):  
Mark Zhang ◽  
Scott Liao ◽  
Sanan Liang ◽  
Ricky Lou ◽  
Rock Chen ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Reliability Test ◽  
Root Cause ◽  
Corrective Actions ◽  
Test Failure

Abstract In this paper, a case of package level reliability test failure was studied. A model of “Slice Defect”, which was identified as the root cause by failure analysis, is introduced. Experiment results are presented to approve that such model is in fact correct and the corrective actions are effective.

Failure Analysis and Process Verification of High-Density Copper ICs Used in Multichip Modules

2017 ◽  
Author(s):  
Jeremy A. Walraven ◽  
Mark W. Jenkins ◽  
Tuyet N. Simmons ◽  
James E. Levy ◽  
Sara E. Jensen ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Failure Analysis ◽  
Root Cause Analysis ◽  
Multichip Modules ◽  
Cause Analysis ◽  
Process Verification ◽  
Root Cause ◽  
Corrective Actions ◽  
Silicon Vias ◽  
Metal Layers

Abstract Manufacturing of integrated circuits (ICs) using a split foundry process expands design space in IC fabrication by employing unique capabilities of multiple foundries and provides added security for IC designers [1]. Defect localization and root cause analysis is critical to failure identification and implementation of corrective actions. In addition to split-foundry fabrication, the device addressed in this publication is comprised of 8 metal layers, aluminum test pads, and tungsten thru-silicon vias (TSVs) making the circuit area > 68% metal. This manuscript addresses the failure analysis efforts involved in root cause analysis, failure analysis findings, and the corrective actions implemented to eliminate these failure mechanisms from occurring in future product.

scholarly journals A New Learning Experience in Gas Turbine Generator a Case Study of Blackout Conditions Due to Tripping of Gtg and the Necessary Corrective Actions to Prevent the Reoccurrence

2020 ◽  
Vol 3 (1) ◽  
Keyword(s):  
Gas Turbine ◽  
Learning Experience ◽  
Total Power ◽  
Turbine Generator ◽  
Root Cause ◽  
Turbine Generators ◽  
Term Basis ◽  
Corrective Actions

This paper describes about the case study of a very interesting and peculiar blackout conditions (total power failure) arising out of both the Gas Turbine Generators (Two units of GTG, namely GTG-01 & GTG-02) units back to back tripping in a short span of a week’s time. It brings out the various observations noted during that condition and it’s root cause analysis. It also highlights the various possible corrective actions in a short term and long term basis to prevent the reoccurrence of such blackout situations.

scholarly journals Pengembangan Metode Percepatan Penjadwalan Pada Keterlambatan Proyek EPC Di Fase Pelaksanaan Dengan Analisa “What If”

2019 ◽  
Vol 8 (2) ◽  
pp. 43-50
Author(s):  
Pratiwi Setyaning Putri ◽  
Hastanto S. M Hastanto S. M
Keyword(s):  
Data Collection ◽  
Critical Path ◽  
Work Productivity ◽  
Critical Path Method ◽  
Root Cause ◽  
Short And Long Term ◽  
Acceleration Method ◽  
Corrective Actions ◽  
Further Development

This study aims to analyze corrective actions that can be done if there is a project delay in one of the activities. Data collection techniques are carried out by observation. The gap between the actual and planned scheduling level (productivity gap) is a problem that must be evaluated and the root cause that causes the decline in work productivity is sought. After further evaluation, it is planned to re-target the acceleration that will be achieved both in the short and long term. The acceleration method for scheduling the duration of the project is done by the critical path method or CPM (Critical Path Method) for further development of corrective actions that can be done to overcome the delay in the duration of the project.

Modeling the causes-effect relationships among major accident predictors based on a fuzzy multi-criteria decision-making method

Work ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 313-321
Author(s):  
Iraj Mohammadfam ◽  
Mostafa Mirzaei Aliabadi ◽  
Ali Reza Soltanian ◽  
Mohsen Mahdinia
Keyword(s):  
Organizational Factors ◽  
Influential Factors ◽  
Accident Prevention ◽  
Fuzzy Dematel ◽  
Safety Communication ◽  
Factors Affecting ◽  
Root Cause ◽  
Communication Work ◽  
Corrective Actions ◽  
Individual Variables

BACKGROUND: Finding the best practices for accident prevention is possible by identifying the influential factors affecting accident occurrence and their interactions as well as implementing corrective actions for the root cause factors. OBJECTIVE: This study was aimed to determine the cause-effect relationships and the interaction of the influential factors affecting accident occurrence and determine the critical root factors. METHODS: This study was carried out based on the opinions of a panel of experts and used the fuzzy DEMATEL method. RESULTS: The results showed that “organization safety attitude”, “safety communication”, “work and safety training” and “safe design of systems” are root cause variables. Also, “work and safety knowledge” and “experience in the job” are individual cause variables. CONCLUSIONS: Organizational factors and some of individual variables are the critical factors that affect the occurrence of accidents. Therefore, corrective actions for accident prevention should primarily focus on the correction of these variables.

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