SNF calculates isotopic concentrations, radiation source terms, and decay heat of spent PWR and BWR fuel. Using the detailed, 3D power history from SIMULATE and isotopic inventories from CASMO, SNF provides the most accurate spent fuel analysis available.

Consistent Methods

SNF uses the detailed histories from CASMO and SIMULATE to accurately model any LWR fuel.

Enhanced Modeling

SNF includes enhanced mixed-oxide (MOX) modeling and the must current neutron yield data available.

Better Cask Utilization

SNF’s robust models and detailed fuel history data help prevent partially loaded storage casks.

Consistent Methods: More Accurate Analysis

SNF leverages the precise neutron spectra, detailed power histories, and the explicit nodal representation of fuel assemblies from CASMO and SIMULATE. These multi-dimensional methods provide a robust evaluation of isotopic concentrations, radiation source terms, photon spectra, and decay heat of spent nuclear fuel, ensuring accurate modeling of spent fuel.

Since SNF uses the isotopic concentrations and power history from standard core-tracking calculations, all that is needed to run SNF is a CASMO/SIMULATE core model. Any configuration of light water reactor fuel that can be modeled in CASMO may be analyzed with SNF. Core designers and reactor engineers can work in parallel to develop both the CASMO isotopic concentrations and the SIMULATE core follow data that is loaded into SNF.

SNF can be coupled to GARDEL, Studsvik’s on-line core monitoring software, to predict real-time decay heat results for the operating core and spent fuel pool and to assess the decay heat of fuel in the reactor after scram or during shutdown.

Enhanced Modeling: 3D Spent Nuclear Fuel Representation

SNF includes enhanced mixed-oxide (MOX) modeling, actinide data for decay times up to 100,000 years, and the most current neutron yield data. Coupled with Studsvik’s industry-leading fuel management methods, SNF is the most reliable spent fuel analysis tool available.

SNF has been validated against both international measurements and existing reference codes, such as ORIGEN-S.
Source term validation has been performed against measured neutron emission rates of isotopes such as Cm-242, Cm-244, and Cm-246.

SNF also performed extremely well in comparisons with fuel assembly decay heat measurements of a large number of BWR and PWR spent fuel assemblies at the CLAB storage facility.

Better Cask Utilization: Save Money and Engineering Resources

SNF is designed to increase fuel storage cask utilization. The robust models and detailed fuel history data used by SNF can help prevent partially loaded storage casks, saving money in engineering time and costly cask loads.

By reducing the overly conservative decay heat predictions used in conventional best-estimate cask loading tools, SNF’s accurate results allow utilities to safely load more spent fuel into their casks

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Erin Wehlage

Phone:+1 617 607 7239

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