The effect of gadolinium content on the thermal conductivity of near-stoichiometric (U,Gd)O2 solid solutions

Fukushima, Susumu; Ohmichi, Toshihiko; Maeda, Atsushi; Watanabe, Hitoshi

doi:10.1016/0022-3115(82)90375-0

Cited by 91 publications

(30 citation statements)

References 9 publications

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“…Experimental thermal di ffusivity data in the open literature have been reported by Newman et al (1984), Hirai and lshimoto ( 1991) arid Fukushima (1982). The Newman data were taken using the laserflash method at concentrations of 2.SU wt%, 5.66 wt%, and 8.5 wt% gadolinia at temperatures up to 1880°C.…”

Section: Experimental Evidence For the Effect Of Gadolinia Additionsmentioning

confidence: 99%

FRAPCON-3: Modifications to fuel rod material properties and performance models for high-burnup application

Lanning¹,

Beyer²,

Painter³

1997

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Section: Experimental Evidence For the Effect Of Gadolinia Additionsmentioning

confidence: 99%

FRAPCON-3: Modifications to fuel rod material properties and performance models for high-burnup application

Lanning¹,

Beyer²,

Painter³

1997

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“…A number of studies related to the thermo-physical properties of UO 2 -GdO 1.5 pellets have been published [7][8][9][10][11][12], but there are no reports on the thermal conductivity for a Dy-doped UO 2 pellet. In this study, the thermal conductivities of nearstoichiometric (U 1−y Dy y )O 2 solid solutions, 0 ≤ y ≤ 0.2, were measured from room temperature to 1473 K.…”

Section: Introductionmentioning

confidence: 99%

Variation of the thermal conductivity of (U,Dy)O2 solid solutions as a function of the Dy content

Kim

Joung

Lee

et al. 2007

Journal of Alloys and Compounds

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“…The strong absorption of thermal neutrons in fuel elements with gadolinium results in a higher coefficient of nonuniformity of power release over a fuel assembly. For this reason, the uranium enrichment is decreased in fuel elements with gadolinium, which decreases the burnup of uranium.To decrease the negative effect of the factors indicated above, the granular gadolinium should be arranged heterogeneously in a fuel elements [3]. The size of the granules should be comparable to the fuel micropellets used in high-temperature gas reactors.…”

mentioning

confidence: 99%

“…To decrease the negative effect of the factors indicated above, the granular gadolinium should be arranged heterogeneously in a fuel elements [3]. The size of the granules should be comparable to the fuel micropellets used in high-temperature gas reactors.…”

mentioning

confidence: 99%

Computational method for and analysis of the application of granular absorbers in VVÉR reactors

2006

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Questions concerning the compensation of excess reactivity in pressurized-water reactors by using consumable granular absorbers are examined. A method of computing the spatial-energy distribution of the neutrons in cells with a granular absorber is presented. The neutron-physical and thermophysical characteristics of fuel assemblies with fuel elements based on homogenized and heterogeneous arrangements of gadolinium in them are compared. It is shown that granular absorbers have certain advantages, specifically, they decrease the gadolinium content in the fuel elements and at the same time increase the total number of gadolinium-containing fuel elements in the fuel assemblies. This decreases the maximum power released in the gadolinium-containing fuel elements and the temperature of the fuel during the entire run.The basic ways to improve fuel cycles for pressurized-water reactors are to decrease the volume of the spent fuel and to increase the installed capacity utilization factor (ICUF), which is achieved by increasing the enrichment of the makeup fuel [1]. Indeed, increasing enrichment increases fuel burnup, which decreases the consumption of the fuel assembly for makeup during operation of a reactor at power. A higher ICUF is achieved if the reactor run increases, i.e., the duration of operation without reloading, which is due to an increase of the excess reactivity in a single run.The excess reactivity in pressurized-water reactors is compensated by two methods. The conventional method of liquid regulation is based on dissolving a boron absorber in the coolant. In this case, the absorber is placed uniformly in the core and is regulatable. Technological and physical factors limit the reactivity excess, which a liquid regulation system compensates. The physical factors include a negative effect of the boron absorber on the coefficient of reactivity on the moderator temperature.The second method for compensating excess reactivity is to place an absorber in the fuel elements in a mixture with the fuel and separately from the fuel. In this case, the consumable absorber in the core is arranged heterogeneously, and its effect on the reactivity is not regulated. Natural gadolinium is most widely used as the consumable absorber. It is a strong absorber, and for this reason it is placed in a small number of fuel elements of each fuel assembly. The required amount of gadolinium in a fuel element is several percent, so that the thermal conductivity decreases [2]. The strong absorption of thermal neutrons in fuel elements with gadolinium results in a higher coefficient of nonuniformity of power release over a fuel assembly. For this reason, the uranium enrichment is decreased in fuel elements with gadolinium, which decreases the burnup of uranium.To decrease the negative effect of the factors indicated above, the granular gadolinium should be arranged heterogeneously in a fuel elements [3]. The size of the granules should be comparable to the fuel micropellets used in high-temperature gas reactors. The use of gadolinium i...

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The effect of gadolinium content on the thermal conductivity of near-stoichiometric (U,Gd)O2 solid solutions

Cited by 91 publications

References 9 publications

FRAPCON-3: Modifications to fuel rod material properties and performance models for high-burnup application

FRAPCON-3: Modifications to fuel rod material properties and performance models for high-burnup application

Variation of the thermal conductivity of (U,Dy)O2 solid solutions as a function of the Dy content

Computational method for and analysis of the application of granular absorbers in VVÉR reactors

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