Study on the Characteristics of Effective Delayed Neutron Fraction (βeff) for Pebble-Bed Reactor with Plutonium Fuel

Zuhair,; Suwoto, Suwoto; Setiadipura, Topan; Kuijper, Jim C.

doi:10.1007/s40995-019-00772-8

Cited by 15 publications

(4 citation statements)

References 20 publications

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“…The structural components of the reactor core such as graphite reflectors were easily modeled while the coolant in the reflector side and especially, the reactor shutdown and control systems require special effort in modeling. The modeling and calculations performed in this study were demonstrated successfully in various publications [11][12][13][14][15][16][17][18][19][20][21][22].…”

Section: Pebbles In Core Modelingmentioning

confidence: 76%

Effects of Fuel Density on Reactivity Coefficients and Kinetic Parameters of Pebble Bed Reactor

Suwoto¹,

Dwijayanto²,

Luthfi³

et al. 2022

urania

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EFFECTS OF FUEL DENSITY ON REACTIVITY COEFFICIENTS AND KINETIC PARAMETERS OF PEBBLE BED REACTOR. Few decades ago a large number of nuclear reactors were designed to use HEU as the fuel. But the use of HEU is being discouraged since it can be used as a nuclear explosive material which makes its proliferation potential. Most of the HEU-fueled nuclear reactors in the world are either closed or converted into other types that have LEU fuel with 235U enrichment below 20%. To extend lifetime, LEU fuel with high density is developed. The change in fuel density from low to high will also change core neutronics and thermal-hydraulics of the reactor, and as a result, it affects the transient response of the reactor. This paper studies the effects of fuel density on reactivity coefficients and kinetic parameters of pebble bed reactor through several calculations with MCNP6 code combine with ENDF/B-VII.1 continuous energy cross-section nuclear data library. The overall calculation results show that the Doppler temperature coefficient (DTC) increases with increasing fuel density, but the moderator temperature coefficient (MTC) decreases due to hardening of neutron spectrum. Kinetic parameters such as effective delayed neutron fraction (βeff), prompt neutron lifetime(ℓ) and neutron generation time (Ʌ) which significantly reduced with increasing fuel density will strongly affect the reactor control and safety. The results of this work conclude that the selection of 9–15 g/cm3 fuel density should be considered carefully given that its effect on reactor controllability.Keywords: Fuel density, reactivity coefficients, kinetic parameters, MCNP6, ENDF/B-VII.1.

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Section: Pebbles In Core Modelingmentioning

confidence: 76%

Effects of Fuel Density on Reactivity Coefficients and Kinetic Parameters of Pebble Bed Reactor

Suwoto¹,

Dwijayanto²,

Luthfi³

et al. 2022

urania

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“…The addition of Th-232, which is pure fertile material, also contributes to the reduced β eff values. However, as reported by Zuhair et al, 68 the incorporation of Th-232 into plutonium cores increases both the prompt neutron lifetime and the generation time, so it may improve reactor safety. For the ThO 2 + UO 2 cores, the introduction of ThO 2 also decreased the fractions of β eff by 1%.…”

Section: Effective Delayed Neutron Fractionmentioning

confidence: 83%

A comparative analysis of the neutronic performance of thorium mixed with uranium or plutonium in a high‐temperature pebble‐bed reactor

et al. 2021

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“…The graphite reflector and other reactor geometry, such as carbon layer around the system, helium channels and control rods, were modelled in detail and comprehensively. The modelling procedure in this study was first developed by Lebenhaft [16] and utilized in some publications [17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Figure 4 illustrates the MCNP6 model for the second heterogeneity of the pebble bed reactor.…”

Section: Fuel Kernelmentioning

confidence: 99%

Study on McNp6 Model in the Calculation of Kinetic Parameters for Pebble Bed Reactor

et al. 2020

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When conducting a nuclear reactor transient analysis, the most important parameter, called the kinetic parameter, is required. The calculation of kinetic parameters can be conducted using several methods. The deterministic method is one possible method that relies on the forward and adjoint neutron fluxes to provide the kinetic parameters calculation based on the perturbation theory. In this study, the Monte Carlo transport code MCNP6 was utilized to perform the exact prediction of the kinetic parameters of a pebble bed reactor. The core was modelled with a different fuel composition of uranium loading per pebble, 235U enrichment and H/D ratio. It was found that keff strongly depends on the uranium loading, uranium enrichment and H/D ratio while the βeff dependence is insignificant. The increase in the prompt neutron lifetime (ℓ) and mean generation time (Ʌ) as a function of H/D ratio are insignificant as compared to the decrease of those parameters in the case of uranium loading or uranium enrichment. These results conclude that the selection of uranium loading per pebble, 235U enrichment and H/D ratio should be considered carefully for the control and inherent safety performances

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Study on the Characteristics of Effective Delayed Neutron Fraction (βeff) for Pebble-Bed Reactor with Plutonium Fuel

Cited by 15 publications

References 20 publications

Effects of Fuel Density on Reactivity Coefficients and Kinetic Parameters of Pebble Bed Reactor

Effects of Fuel Density on Reactivity Coefficients and Kinetic Parameters of Pebble Bed Reactor

A comparative analysis of the neutronic performance of thorium mixed with uranium or plutonium in a high‐temperature pebble‐bed reactor

Study on McNp6 Model in the Calculation of Kinetic Parameters for Pebble Bed Reactor

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