Seismic response of the advanced gas cooled reactor core

Ahmed, K.M.; Parker, James; Proffitt, D.E.

doi:10.1016/0029-5493(86)90154-8

Cited by 5 publications

(5 citation statements)

References 3 publications

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“…The physical model developed by the University of Bristol is analogous to the GCORE numerical model developed using the LS‐DYNA platform . It is built at quarter scale based on an AGR core late in life .…”

Section: Agr Core Physical Model Descriptionmentioning

confidence: 99%

“…The physical model developed by the University of Bristol is analogous to the GCORE numerical model developed using the LS-DYNA platform. [38][39][40][41] It is built at quarter scale based on an AGR core late in life. 42 Instead of graphite, which is brittle, difficult to manufacture, dirty to handle, and subject to dust production through wear during shaking, an engineering plastic called Acetal was selected for the physical model components as it offers increased resilience, and its properties are well matched to that of graphite.…”

Section: Agr Core Physical Model Descriptionmentioning

confidence: 99%

“…The first method for predicting the seismic responses of AGR reactor cores was developed in the early 1980s using arrays of rigid bodies and nonlinear contact elements . This method was supported by an extensive set of dynamic excitation tests on small arrays of full‐size bricks and brick slices . Seismic responses of AGR reactor cores are currently computed by GCORE, which uses representations of the arrays of graphite bricks similar to those used earlier …”

Section: Introductionmentioning

confidence: 99%

“…37 This method was supported by an extensive set of dynamic excitation tests on small arrays of full-size bricks and brick slices. 38,39 Seismic responses of AGR reactor cores are currently computed by GCORE, 40 which uses representations of the arrays of graphite bricks similar to those used earlier. 37 The problem is both important and challenging because of its implications in the safe operation of the core and because it goes beyond the state of the art in the area of multiblock dynamics.…”

Section: Introductionmentioning

confidence: 99%

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Earthquake response of a multiblock nuclear reactor graphite core: Experimental model vs simulations

Voyagaki

Kloukinas

Dietz

et al. 2018

Earthq Engng Struct Dyn

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Summary The complex dynamics of a quarter‐scale model of a graphite nuclear reactor core, representative of the second generation of British advanced gas‐cooled nuclear reactors, is investigated numerically and experimentally. Advanced gas‐cooled nuclear reactor cores are polygonal, multilayer, arrays of graphite bricks, with each brick allowed to rock by design relative to each other in accordance with the boundary conditions. A 35 000 DOF, nonlinear finite element model of the core created by Atkins Nuclear, was analysed on a high performance computing facility at the University of Bristol, and a corresponding 8 t physical model, equipped with 3200 data acquisition channels, was built and tested on the University of Bristol 6‐DOF shaking table. In this paper, the two models are subjected to a series of (1) synthetic earthquake and (2) idealised harmonic input motions. The experimental data are used to compare and verify the two models and explore the dynamics of the core. A kinematic model of the response is also developed based solely on geometric constraints. The results are presented in the form of response maps and graphs. Important conclusions are drawn as to the dynamics and earthquake response of such systems, which inform numerical model validation. It is found that contrary to the case of a small number of rocking blocks that exhibit highly complex response patterns, the behaviour of the model at hand is both smooth and repeatable. An analogy between the response of the core and that of dense granular matter exhibiting particle interlocking and dilatancy is highlighted.

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Section: Agr Core Physical Model Descriptionmentioning

confidence: 99%

Section: Agr Core Physical Model Descriptionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Earthquake response of a multiblock nuclear reactor graphite core: Experimental model vs simulations

Voyagaki

Kloukinas

Dietz

et al. 2018

Earthq Engng Struct Dyn

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“…A layer of Upper Neutron Shield of graphite bricks covers the assembly. The whole system is kept laterally stable using a system of restrain rods and beams, centralising brackets and Warwick links tied to restrain rings (Ahmed, et al, 1986).…”

Section: Introductionmentioning

confidence: 99%

Large-Scale Modeling of Damage and Failure of Nuclear Graphite Moderated Reactor

Farrokhnia

Jivkov

Hall

et al. 2022

Journal of Pressure Vessel Technology

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The UK Advanced Gas-Cooled reactors (AGRs) have cores made of graphite bricks with dual functions: as structural elements of the core, providing space for and separating fuel and control rods; and as moderator of the nuclear reaction. Nuclear graphite is a quasi-brittle material, where the dominant mechanism for failure is cracking. While cracking of isolated bricks is expected due to operation-induced changes in graphite microstructure and stress fields, these could be tolerated as far as the overall structural function of the core is maintained. Assessment of the whole core behaviour has been previously done with whole scale models where bricks have been considered as rigid body elements connected by elastic-brittle springs. This approach does not allow for the realistic assessment of the stresses in the bricks and associated brick cracking. Reported here are results from an ongoing project, which addresses this shortcoming. The proposed model uses deformable bricks with appropriate interactions, allowing for physically realistic whole core analysis. The results are focused on the damage that a graphite moderated reactor develops during a life cycle, how this affects the behaviour of the whole core, and how changes in bricks' behaviour impacts the core integrity. The proposed methodology is a major step towards high-fidelity assessment of AGRs' fitness for service, required for supporting continuous safe operation and life-extension decisions.

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Numerical study of the dynamic characteristics of a single-layer graphite core in a thorium molten salt reactor

Yang

Ding

et al. 2018

NUCL SCI TECH

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Seismic response of the advanced gas cooled reactor core

Cited by 5 publications

References 3 publications

Earthquake response of a multiblock nuclear reactor graphite core: Experimental model vs simulations

Earthquake response of a multiblock nuclear reactor graphite core: Experimental model vs simulations

Large-Scale Modeling of Damage and Failure of Nuclear Graphite Moderated Reactor

Numerical study of the dynamic characteristics of a single-layer graphite core in a thorium molten salt reactor

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