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NN Asks: What hurdles stand in the way of nuclear power’s global expansion?
Jake Jurewicz
Nuclear technology is mature. It provides firm power at scale with minimal externalities and has done so for decades. The core problem isn’t about the technology—it is how the plants are built. Nuclear construction has a well-documented history of cost and schedule overruns. Previous nuclear plants often spent more than twice what was first budgeted, making nuclear among the power technologies with the largest average cost overruns worldwide.
Recent projects illustrate how severe the problem can be. In South Carolina, the V.C. Summer nuclear expansion saw projected costs rise from roughly $10 billion to more than $25 billion before the project was abandoned in 2017, by which time more than $9 billion had already been spent and customers were stuck paying for a site they have yet to benefit from.
Kyra Lawson, Nicholas R. Brown
Nuclear Technology | Volume 210 | Number 11 | November 2024 | Pages 2133-2150
Research Article | doi.org/10.1080/00295450.2024.2310911
Articles are hosted by Taylor and Francis Online.
This work presents neutronics models of a small and large fast-spectrum molten chloride-salt reactor. The models are similar to designs being pursued by industry, and they may serve as generic preconceptual and simplified neutronics models that provide information for decision making in licensing-related areas. The two models were created using Serpent, a Monte Carlo neutron transport code, and Moltres, a neutron diffusion core simulator tool. Specifically, this study focused on exploring the applicability of diffusion theory to fast molten salt reactor (MSR) models, the capabilities of an open-source, MSR-oriented simulation tool (Moltres), and optimal energy-group structures.
The proposed two-step method involves group-constant generation with Serpent and a multigroup diffusion solution by Moltres. Three energy-group structures were applied. The accuracy of the solutions was determined through comparisons between the two-step and Monte Carlo flux and multiplication factor solutions.
The findings indicated diffusion theory captures neutronics with minimal error for the large MSR and yielded best results with the 27-group structure. The 27-group structure yielded an average group flux error below 2% and keff agreement between diffusion and transport solutions within 30 pcm. The accuracy of the two-step method decreased for the very small (high-leakage) fast chloride MSR, but the neutronics were captured acceptably well with the 33-group structure.
In addition to exploring the capabilities of Moltres, this work contributes to the sparse literature involving open-source models of fast-spectrum MSRs. Future work is noted as expanding the capabilities of the neutronics models to incorporate thermal hydraulics.
