CSAU methodology and results for an ATWS event in a BWR using information theory methods

Muñoz-Cobo, J.L.; Escrivá, A.; Mendizábal, Rafael; Pelayo, Fernando L.; Melara, J.

doi:10.1016/j.nucengdes.2014.07.036

Cited by 9 publications

(18 citation statements)

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“…If f X (x) denotes the probability density function of the random parameter X, and F X (x) the cumulative distribution function, Claude Shannon defined the concept of information entropy H as a measurement of the uncertainty associated to the result of a given process [9]. If X has a compact support, i.e., the random variable X can take values between a and b, with b > a, being [a, b] the distribution support; then the Shannon information entropy is defined by the expression [5,9,10,16] …”

Section: Application Of the Mep To The Case Of Knowledge Of Some Momementioning

confidence: 99%

“…The problem to be solved in information theory when applying the MEP is to obtain the PDF expression f X (x) that maximizes the information entropy and, at the same time, obeys the set of restrictions displayed in Equation (5). To solve this problem, variational calculus is generally used and, first, we build the following functional J[ f X (x)] that includes the restrictions of Equation (5) by means of the Lagrange multiplier method…”

Section: Application Of the Mep To The Case Of Knowledge Of Some Momementioning

confidence: 99%

“…The values of the constants λ i are obtained from the available information on the distribution moments given by the set of Equation (5). In general, to obtain the parameter values of λ i it is necessary to solve a non-linear system of algebraic equations as will be shown later.…”

Section: Application Of the Mep To The Case Of Knowledge Of Some Momementioning

confidence: 99%

“…In general, these codes need a set of input data that can be classified as: initial and boundary conditions, geometric data, physical property data, and model parameter data. The methodologies known as BEPU, meaning Best-Estimate Plus Uncertainty, try to estimate the uncertainty in the code response once the uncertainty in the input and model data have been obtained and propagated from the input to the output [4,5]. These methodologies provide a set of output results plus their uncertainties in the form of tolerance regions with prescribed levels of coverage and confidence, usually 95/95, meaning a 95% of coverage and 95% confidence.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Use of the Principles of Maximum Entropy and Maximum Relative Entropy for the Determination of Uncertain Parameter Distributions in Engineering Applications

Muñoz-Cobo

Mendizábal

Miquel

et al. 2017

Entropy

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Abstract:The determination of the probability distribution function (PDF) of uncertain input and model parameters in engineering application codes is an issue of importance for uncertainty quantification methods. One of the approaches that can be used for the PDF determination of input and model parameters is the application of methods based on the maximum entropy principle (MEP) and the maximum relative entropy (MREP). These methods determine the PDF that maximizes the information entropy when only partial information about the parameter distribution is known, such as some moments of the distribution and its support. In addition, this paper shows the application of the MREP to update the PDF when the parameter must fulfill some technical specifications (TS) imposed by the regulations. Three computer programs have been developed: GEDIPA, which provides the parameter PDF using empirical distribution function (EDF) methods; UNTHERCO, which performs the Monte Carlo sampling on the parameter distribution; and DCP, which updates the PDF considering the TS and the MREP. Finally, the paper displays several applications and examples for the determination of the PDF applying the MEP and the MREP, and the influence of several factors on the PDF.

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Section: Application Of the Mep To The Case Of Knowledge Of Some Momementioning

confidence: 99%

Section: Application Of the Mep To The Case Of Knowledge Of Some Momementioning

confidence: 99%

Section: Application Of the Mep To The Case Of Knowledge Of Some Momementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Use of the Principles of Maximum Entropy and Maximum Relative Entropy for the Determination of Uncertain Parameter Distributions in Engineering Applications

Muñoz-Cobo

Mendizábal

Miquel

et al. 2017

Entropy

View full text Add to dashboard Cite

show abstract

“…Before the launching of BEMUSE programme, there were several uncertainty methodologies developed by different institutions. The first uncertainty analysis used to support licensing process was the CSAU (code scaling, applicability and uncertainty) methodology that was developed by the USNRC in 1988 [11]. In 1985, Gessellschaft fur Anlagen und Reactor Sicherheits (GRS) in Germany proposed a probabilistic uncertanty analysis method called the GRS method, which is slightly different with the CSAU method [12].…”

Section: Introductionmentioning

confidence: 99%

Preliminary Study on Relap5 Simulation of Dvi Line Break Accident in the Atlas Facility Using Best Estimate Plus Uncertainty Method

Ekariansyah

Widodo

2017

Tri Dasa Mega

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PRELIMINARY STUDY ON RELAP5 SIMULATION OF DVI LINE BREAK ACCIDENT IN THE ATLAS FACILITY USING BEST ESTIMATE PLUS UNCERTAINTY METHOD. The BestEstimate plus Uncertainty (BEPU) is a methodology, which was introduced in the deterministic safety analysis to evaluate limitations of codes in simulating realistic plant behavior by providing quantified uncertainty bands of calculation results. It has been already widely accepted in licensing nuclear power plant by regulatory bodies of United States (USNRC), Argentina, and Canada. The uncertainty evaluation in the BEPU method is performed by different approaches such as GRS, IRSN, ENUSA, AEAT, and UNIPI. Due to the complexity of other approaches, the purpose of this study is to present some key aspects of the BEPU process using the GRS methodology by selecting the ATLAS test facility to simulate 50% break of DVI line since any safety analysis performed so far was using deterministic best estimate approach only. As comparison of the best estimate simulation performed by RELAP5/SCDAP/Mod3.4, experimental data related to the event was used. After 100 simulations, the uncertainty bands of peak heater of clad temperature and primary pressure transient obtained were only in a close agreement with the experimental data in the earlier period and less than 250 seconds during the transient condition. Therefore the overall accuracy of the best estimate simulation plays a key role on the final results of the uncertainty analysis because the propagation of any discrepancy in the best estimate with the experimental data will occur throughout the simulation. After that, selecting the important parameters to be randomly generated needs to be performed carefully by studying the important phenomena related to the event analyzed and associated plant model. Keywords: best estimate plus uncertainty, DVI line break, ATLAS facility, RELAP5, simulation ABSTRAK STUDI AWAL SIMULASI KECELAKAAN PUTUSNYA JALUR DVI PADA FASILITAS ATLAS MENGGUNAKAN RELAP5 DENGAN METODE ESTIMASI TERBAIK DAN KETIDAKPASTIAN. Metode Best estimate plus uncertainty (BEPU) adalah metode analisis keselamatan deterministik yang bertujuan untuk melakukan evaluasi keterbatasan program perhitungan dalam mensimulasikan sifat-sifat fisis instalasi secara realistik dengan mengkuantifikasi rentang ketidakpastian dari hasil perhitungan. Metode tersebut telah diterima secara luas dalam perijinan PLTN oleh badan pengatur dunia seperti di

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Applications of SYS TH codes to nuclear reactor design and accident analysis

D'Auria

Galassi

2017

Thermal-Hydraulics of Water Cooled Nuclear Reactors

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CSAU methodology and results for an ATWS event in a BWR using information theory methods

Cited by 9 publications

References 10 publications

Use of the Principles of Maximum Entropy and Maximum Relative Entropy for the Determination of Uncertain Parameter Distributions in Engineering Applications

Use of the Principles of Maximum Entropy and Maximum Relative Entropy for the Determination of Uncertain Parameter Distributions in Engineering Applications

Preliminary Study on Relap5 Simulation of Dvi Line Break Accident in the Atlas Facility Using Best Estimate Plus Uncertainty Method

Applications of SYS TH codes to nuclear reactor design and accident analysis

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