On the use of spectral algorithms for the prediction of short-lived volatile fission product release: Methodology for bounding numerical error

Towards grain-scale modelling of the release of radioactive fission gas from oxide fuel. Part II: Coupling SCIANTIX with TRANSURANUS

“…8 In Part I we detailed the SCIANTIX modelling for the radioactive fission gases at the intra-and inter-granular scale of the fuel grain. The intra-granular radioactive gas behaviour is built on the time-dependent solution of the diffusion-decay equation in an equivalent spherical grain [15,56,57]. The trapping in and resolution from intra-granular gas bubbles are approached in accordance to Refs.…”

“…Namely, during the power transient, the gas diffuses from the intra-granular region towards the grain-boundary. 15 The gas variation in the grain-boundary region (Fig. 13b) shows that TRANSURANUS//SCIANTIX predicts a gas depletion across the entire radial dimension (resulting in increased gas release).…”

“…Eventually, thanks to the coupling with SCIANTIX (outlined in the next Section 2.3), TRANSURANUS inherits the SCIANTIX physics-based models for intra-and inter-granular stable fission gas behaviour [12,42,43,48], helium behaviour [44] and radioactive fission gas behaviour [15,21].…”