Neutron noise calculation: A comparative study between SP3 theory and diffusion theory

Abstract Calculation of neutron noise precisely can play an important role in monitoring and safety, as the knowledge from neutron noise analysis is useful for core monitoring, diagnostics and surveillance of a power reactor core. In this work, we propose applying the SP3 transport approximation for neutron noise calculation. Generally, the SP3 approximation theory is capable of capturing partly the neutron transport effect without a severe increase in computational burden and code complexity than diffusion theory. As a preliminary work, a prototype code called CORCA-NOISE is developed and integrated into the industry SP3 solver CORCA-PIN. Numerical results on two benchmarks show some deviation of the noise function derived from SP3 and diffusion theories, which means that further theoretical analysis and numerical simulations are necessary to demonstrate the effectiveness of SP3 noise theory.

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