Tunc Aldemir - Academia.edu (original) (raw)

Papers by Tunc Aldemir

In support of expanding the use of nuclear power, interest is growing in methods of determining t... more In support of expanding the use of nuclear power, interest is growing in methods of determining the feasibility of longer term operation for the U.S. fleet of nuclear power plants, particularly operation beyond 60 years. To help establish the scientific and technical basis for such longer term operation, the DOE-NE has established a research and development (R&D) objective. This objective seeks to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the life of current reactors. The Light Water Reactor Sustainability (LWRS) Program, which addresses the needs of this objective, is being developed in collaboration with industry R&D programs to provide the technical foundations for licensing and managing the long-term, safe, and economical operation of nuclear power plants. The LWRS Program focus is on longer-term and higher-risk/reward research that contributes to the national policy objectives of energy and environmental security. In moving to identify priorities and plan activities, the Light Water Reactor Sustainability Workshop on On-Line Monitoring (OLM) Technologies was held June 10-12, 2010, in Seattle, Washington. The workshop was run to enable industry stakeholders and researchers to identify the nuclear industry needs in the areas of future OLM technologies and corresponding technology gaps and research capabilities. It also sought to identify approaches for collaboration that would be able to bridge or fill the technology gaps. This report is the meeting proceedings, documenting the presentations and discussions of the workshop and is intended to serve as a basis for a plan which is under development that will enable the I&C research pathway to achieve its goals. Benefits to the nuclear industry accruing from On Line Monitoring Technology cannot be ignored. Information gathered thus far has contributed significantly to the Department of Energy's Light Water Reactor Sustainability Program. DOE has shown great interest in supplying necessary support to help this industry to move forward as indicated by the recent workshop conducted in support of this interest. The Light Water Reactor Sustainability Workshop on On-Line Monitoring Technologies provided an opportunity for industry stakeholders and researchers to gather in order to collectively identify the nuclear industry's needs in the areas of OLM technologies including diagnostics, prognostics, and RUL. Additionally, the workshop provided the opportunity for attendees to pinpoint technology gaps and research capabilities along with the fostering of future collaboration in order to bridge the gaps identified. Attendees concluded that a research and development program is critical to future nuclear operations. Program activities would result in enhancing and modernizing the critical capabilities of instrumentation, information, and control technologies for long-term nuclear asset operation and management. Adopting a comprehensive On Line Monitoring research program intends to: Develop national capabilities at the university and laboratory level Create or renew infrastructure needed for long-term research, education, and testing Support development and testing of needed I&C technologies Improve understanding of, confidence in, and decisions to employ these new technologies in the nuclear power sector and achieve successful licensing and deployment.

OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), Apr 1, 2021

The DSD (Dynamic System Doctor) is system independent, stateIparameter estimation software. The D... more The DSD (Dynamic System Doctor) is system independent, stateIparameter estimation software. The DSD is based on the modeling of system evolution in terms of probability of transitions within user specified time intervals between sets of user defined parameterIstate variable magnitude intervals that partition the system state space. Recently a recursive partitioning scheme has been developed for DSD that reduces the estimation time and memory requirements, as well as making DSD more user friendly. The scheme is illustrated using a non-linear model for the constant temperature power sensor, proposed for direct core power distribution monitoring in Generation 4 nuclear power reactors

Severe Accident Management Guidelines (SAMGs) are an important piece of a utility’s strategy for ... more Severe Accident Management Guidelines (SAMGs) are an important piece of a utility’s strategy for minimizing impacts of an accident. Human Reliability Assessment (HRA) within SAMGs has not been thoroughly investigated. An integrated and history-dependent HRA/SAMG model was developed at The Ohio State University to explore possible human actions that may need to be taken following an accident for their verification though simulation. The system under consideration is a pressurized water reactor undergoing a short-term station blackout initiating event (IE). The PWR behavior following the IE was simulated using the MELCOR code. The simulations showed that severe accident space is reached quickly based on an assumption of the residual water storage tank being unavailable. The data from the MELCOR model were input into the HRA model every ten minutes after the onset of fuel damage in MELCOR as input for operator actions. Results were obtained using ten sequences sampled from MELCOR data ...

Modern Nuclear Energy Analysis Methods, 2017

Probabilistic Safety Assessment and Management, 2004

Some applications of dynamic methodologies for process system reliability and safety analyses are... more Some applications of dynamic methodologies for process system reliability and safety analyses are described and the advantages and limitations of these methodologies are discussed.

Nuclear Technology, Oct 1, 2003

While techniques have been developed to tackle different tasks in accident management, there have... more While techniques have been developed to tackle different tasks in accident management, there have been very few attempts to develop an on-line operator assistance tool for accident management and none that can be found in the literature that uses probabilistic arguments, which are important in today's licensing climate. The state/parameter estimation capability of the dynamic system doctor (DSD) approach is

131 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1978.U of I OnlyRestricted to t... more 131 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1978.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

arXiv (Cornell University), Apr 10, 2018

The level of autonomous functions in vehicular control systems has been on a steady rise. This ri... more The level of autonomous functions in vehicular control systems has been on a steady rise. This rise makes it more challenging for control system engineers to ensure a high level of safety, especially against unexpected failures such as stochastic hardware failures. A generic Backtracking Process Algorithm (BPA) based on a deductive implementation of the Markov/Cell-to-Cell Mapping technique is proposed for the identification of critical scenarios leading to the violation of safety goals. A discretized state-space representation of the system allows tracing of fault propagation throughout the system, and the quantification of probabilistic system evolution in time. A case study of a Hybrid State Control System for an autonomous vehicle prone to a brake-by-wire failure is constructed. The hazard of interest is collision with a stationary vehicle. The BPA is implemented to identify the risk significant scenarios leading to the hazard of interest.

Annals of Nuclear Energy, Feb 1, 2013

ABSTRACT

Reliability Engineering & System Safety, 2016

IEEE Transactions on Reliability, Apr 1, 1987

... Tunc Aldemir ... Useful features of the methodology are: 1) failure model titioning [25] of t... more ... Tunc Aldemir ... Useful features of the methodology are: 1) failure model titioning [25] of the control space and its complement (sec-accuracy can be verified or improved by a change in the input data tion 6.1) for mechanized model construction, 2) effect of changes in system ...

Modern nuclear energy analysis methods, Apr 26, 2017

Nuclear Technology, Oct 1, 1995

In the nuclear industry, aging effects have been traditionally incorporated into probabilistic ri... more In the nuclear industry, aging effects have been traditionally incorporated into probabilistic risk assessment studies by using a constant (static) unavailability (qs) averaged over time. However, recent work shows that because of aging, substantial deviations may occur in time-dependent component unavailability from that predicted by static models well within the plant lifetime. A methodology based on the standard extension of

Transactions of the American Nuclear Society, 1986

The use of checkerboard pattern of alternating inserted and fully withdrawn control rods and the ... more The use of checkerboard pattern of alternating inserted and fully withdrawn control rods and the uneven void distribution in boiling water reactor (BWR) cores can cause large burnup gradients even after a short time of operation. To compensate for these effects, power has to be reshaped periodically (typically every two full-power months) by individually manipulating the control rods. During this

Nuclear Technology, Feb 23, 2023

Modern nuclear energy analysis methods, Apr 25, 2018