scholarly journals Calculation of fuel temperature profile for heavy water moderated natural uranium oxide fuel using two gas mixture conductance model for noble gas Helium and Xenon

2020 ◽  
Vol 52 (12) ◽  
pp. 2760-2770
Author(s):  
Alok Jha ◽  
Anurag Gupta ◽  
Rajarshi Das ◽  
Shantanu D. Paraswar
Keyword(s):  
Temperature Profile ◽  
Heavy Water ◽  
Uranium Oxide ◽  
Noble Gas ◽  
Natural Uranium ◽  
Gas Mixture ◽  
Oxide Fuel ◽  
Fuel Temperature

Comparison of the Reactivity Effects Calculated by DRAGON and Serpent for a PHWR 37-Element Fuel Bundle

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Jawad Haroon ◽  
Leslie Kicka ◽  
Subhramanyu Mohapatra ◽  
Eleodor Nichita ◽  
Peter Schwanke
Keyword(s):  
Monte Carlo ◽  
Heavy Water ◽  
Monte Carlo Methods ◽  
Statistical Error ◽  
Natural Uranium ◽  
Monte Carlo Code ◽  
Fuel Temperature ◽  
Fuel Bundle ◽  
Deterministic Methods ◽  
Heavy Water Reactor

Deterministic and Monte Carlo methods are regularly employed to conduct lattice calculations. Monte Carlo methods can effectively model a large range of complex geometries and, compared to deterministic methods, they have the major advantage of reducing systematic errors and are computationally effective when integral quantities such as effective multiplication factor or reactivity are calculated. In contrast, deterministic methods do introduce discretization approximations but usually require shorter computation times than Monte Carlo methods when detailed flux and reaction-rate solutions are sought. This work compares the results of the deterministic code DRAGON to the Monte Carlo code Serpent in the calculation of the reactivity effects for a pressurized heavy water reactor (PHWR) lattice cell containing a 37-element, natural uranium fuel bundle with heavy water coolant and moderator. The reactivity effects are determined for changes to the coolant, moderator, and fuel temperatures and to the coolant and moderator densities for zero-burnup, mid-burnup [3750  MWd/t(U)] and discharge burnup [7500  MWd/t(U)] fuel. It is found that the overall trend in the reactivity effects calculated using DRAGON match those calculated using Serpent for the burnup cases considered. However, differences that exceed the amount attributable to statistical error have been found for some reactivity effects, particularly for perturbations to coolant and moderator density and fuel temperature.

scholarly journals Influence of anodic gas mixture composition on solid oxide fuel cell performance: Part 1

2016 ◽  
Vol 34 (Special Issue 2) ◽  
pp. S303-S308 ◽  
Author(s):  
N. Murgi ◽  
G. Lorenzo ◽  
O. Corigliano ◽  
F. Mirandola ◽  
P. Fragiacomo
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Cell Performance ◽  
Mixture Composition ◽  
Gas Mixture ◽  
Oxide Fuel ◽  
Fuel Cell Performance ◽  
Anodic Gas

Stress Re-Distribution Induced by Creep Relaxation Around a Notch Loaded in Tension: Measurement and Modeling

2009 ◽  
Author(s):  
Brian W. Leitch ◽  
Nicolas Christodoulou ◽  
Ronald Rogge
Keyword(s):  
Heavy Water ◽  
Strain Field ◽  
High Stress ◽  
Natural Uranium ◽  
Thermal Creep ◽  
Three Dimensions ◽  
Pressure Tube ◽  
Primary Coolant ◽  
Fuel Channel ◽  
Creep Response

The majority of the pressure-retaining components in the core of a CANDU power generation system are manufactured from zirconium. The horizontal fuel channel components and the fuel bundles that contain the natural uranium fuel are manufactured using various grades of zirconium. The fuel channel consists of two concentric tubes; an internally pressurized tube (Zr-2.5%Nb) that contains the fuel bundles (Zr-4) and the re-circulating heavy-water primary coolant, enclosed by a larger diameter calandria tube (Zircaloy) that separates the pressure tube from the heavy-water moderator. Re-fuelling and other fuel management operations can create surface defects in the tubes and fuel bundle sheathing. Stress analyses of these small notches may indicate that, under certain conditions, cracks can be formed at the root of these notches. These flaws are locations of stress concentration in the internally pressurized tube and can initiate a failure mechanism known as Delayed Hydride Cracking. The anisotropic material properties of these zirconium components adds an additional level of complexity in an analysis. However, the occurrences of these life-limiting events appear to be minimized mainly due to beneficial contributors such as stress relaxation around the scratches. One of the most likely reasons for this relaxation is thermal creep. Previously [1], the measurement and modeling of thermal creep relaxation under constant displacement was examined using 2-D finite element (FE) models. This paper extends both the measurement and modeling of the relaxing stress/strain field to the more demanding boundary condition of constant applied load. Neutron diffraction is used to determine the changing strain field around a single notched, axially orientated specimen loaded in tension. This specimen orientation and loading configuration is modeled in three dimensions using a hybrid explicit FE program [2] that contains materials subroutines that describe high stress creep specially developed to simulate the highly anisotropic creep response of pressure tube materials. Despite the difficulty of obtaining precise delineation of the moving strain field, a good agreement between the measurements and the 3-D FE creep results is achieved. Using the creep subroutines, the FE models are used to examine the creep response of a single notched, transversely orientated specimen loaded in tension in the hoop direction.

Radiation trapping in an alkali-vapor-noble-gas mixture excited by a strong laser pulse

1995 ◽  
Vol 120 (5-6) ◽  
pp. 249-256 ◽  
Author(s):  
N.N Bezuglov ◽  
A.N Klucharev ◽  
B Taratin ◽  
T Stacewicz ◽  
A.F Molisch ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Noble Gas ◽  
Gas Mixture ◽  
Strong Laser ◽  
Radiation Trapping
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