Development of Hafnium and Comparison with Other Pressurized Water Reactor Control Rod Materials

Keller, H.W.; Shallenberger, J.M.; Hollein, David A.; Hott, A.C.

doi:10.13182/nt82-a33005

Cited by 26 publications

(6 citation statements)

References 2 publications

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“…For a review of the development of hafnium and comparison with other pressurized water-reactor control rod materials, see [31]. Hf also has a very high melting point, leading to applications in plasma welding torches [32].…”

Section: Hafnium Transition Metalmentioning

confidence: 99%

Bayesian strategies for uncertainty quantification of the thermodynamic properties of materials

Paulson

Jennings

Stan

2019

International Journal of Engineering Science

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Reliable models of the thermodynamic properties of materials are critical for industrially relevant applications that require a good understanding of equilibrium phase diagrams, thermal and chemical transport, and microstructure evolution. The goal of thermodynamic models is to capture data from both experimental and computational studies and then make reliable predictions when extrapolating to new regions of parameter space. These predictions will be impacted by artifacts present in real data sets such as outliers, systematics errors and unreliable or missing uncertainty bounds. Such issues increase the probability of the thermodynamic model producing erroneous predictions. We present a Bayesian framework for the selection, calibration and quantification of uncertainty of thermodynamic property models. The modular framework addresses numerous concerns regarding thermodynamic models including thermodynamic consistency, robustness to outliers and systematic errors by the use of hyperparameter weightings and robust Likelihood and Prior distribution choices. Furthermore, the framework's inherent transparency (e.g. our choice of probability functions and associated parameters) enables insights into the complex process of thermodynamic assessment. We introduce these concepts through examples where the true property model is known. In addition, we demonstrate the utility of the framework through the creation of a property model from a large set of experimental specific heat and enthalpy measurements of Hafnium metal from 0 to 4900K.

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Section: Hafnium Transition Metalmentioning

confidence: 99%

Bayesian strategies for uncertainty quantification of the thermodynamic properties of materials

Paulson

Jennings

Stan

2019

International Journal of Engineering Science

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“…In this section we present the application of the proposed Bayesian framework to the development of thermodynamic property models for elemental Hafnium (Hf) with quantified uncertainty. Hf is a tetravalent transition metal with applications in nuclear energy, plasma welding, superalloys and electronics [54][55][56][57]. It is suitable as a case study because its high melting and vaporization temperatures (~2500 K and ~4900 K respectively), difficulty of separation from the chemically similar Zirconium (Zr) and susceptibility to oxidation at high temperatures lead to the data problems previously mentioned such as the presence of outliers and data sets with systematic errors.…”

Section: Case Study: Hafniummentioning

confidence: 99%

Uncertainty quantification and propagation in CALPHAD modeling

Honarmandi

Paulson

Arróyave

et al. 2019

Modelling Simul. Mater. Sci. Eng.

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Design is about making decisions bounded by a quantifiable degree of certainty. In the context of alloy design, Integrated Computational Materials Engineering (ICME) provides the framework whereby performance requirements are ultimately transformed into alloy/processing specifications through the combination of (complex) computational models connecting processstructure-property-performance relationships and experiments. Most ICME approaches consider the models used as deterministic and thus do not provide the means to make alloy design decisions with proper confidence measures. At the root of ICME lie CALPHAD models that describe the thermodynamics and phase stability of phases under specific thermodynamic boundary conditions. To date, the vast majority of efforts within the CALPHAD community have been deterministic in that thermodynamic models and the resulting thermodynamic properties and phase diagram features do not explicitly account for the uncertainties inherent in the model formulation or in the experimental/computational data used. In this contribution, we provide an overview of the state of the field. We review major efforts thus far and we then provide a (brief) tutorial on basic concepts of uncertainty quantification and propagation (UQ/UP) in CALPHAD. We discuss the major features of frequentist and Bayesian interpretations of uncertainty and proceed with a discussion of recent case studies in which UQ has been used to parameterize models for the thermodynamic properties of phases. We follow our discussion by presenting frameworks and demonstrating the propagation of uncertainty in

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“…Although Ag-In-Cd alloys are successfully used in commercial pressurized water reactors, the nuclear reactivity of control rod assemblies drops to about 80% of its initial value after five years of operation. Hf has been used as a neutron absorber in the advanced test reactor (ATR); however, because it is difficult to separate from zirconium, elemental Hf is a costly material [ 2 ]. Dy 2 TiO 5 pellets are used as neutron absorbers in Russian thermal reactors, such as VVER-1000 and RBMK, but their neutron absorption capacity decreases quickly with an increase in service time [ 3 , 4 , 5 ].…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Mechanical Properties of Ni-20Cr-Eu2O3 Composites Prepared by Vacuum Hot Pressing

Zhou

Yue

et al. 2023

Materials

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Ni-20Cr-Eu2O3 composites were designed as new control rod materials and were synthesized from Ni, Cr, and Eu2O3 mixture powders via ball milling and vacuum hot pressing. During ball milling, Eu2O3 was fined, nano-crystallized, amorphized, and then dissolved into matrix. The effect of Eu2O3 content on the microstructure and mechanics was researched, and the corresponding mechanism was discussed. The relative densities, grain sizes, and microhardness increased when Eu2O3 content increased. According to the TEM observations, Eu2O3 particles showed a semi-coherent relationship with the matrix. The results of mechanical property testing showed that the ultimate tensile strength, yield strength, and elongation decreased with the Eu2O3 content increased. The maximum ultimate tensile strength, yield strength, and elongation were 741 MPa, 662 MPa, and 4%, respectively, with a 5 wt.% Eu2O3 addition. The experimental strengths were well matched with the theoretical values calculated by the strengthening mechanisms indicating that this method was highly effective for predicting the mechanical properties of Ni-20Cr-Eu2O3 composites.

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Development of Hafnium and Comparison with Other Pressurized Water Reactor Control Rod Materials

Cited by 26 publications

References 2 publications

Bayesian strategies for uncertainty quantification of the thermodynamic properties of materials

Bayesian strategies for uncertainty quantification of the thermodynamic properties of materials

Uncertainty quantification and propagation in CALPHAD modeling

Microstructure and Mechanical Properties of Ni-20Cr-Eu2O3 Composites Prepared by Vacuum Hot Pressing

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