New energy deposition treatment in the Serpent 2 Monte Carlo transport code

Highlights: • A new energy deposition treatment was implemented for Serpent 2. • Both the spatial fidelity and the tallied total energy deposition are improved. • The treatment is demonstrated with simple test cases. • A high-level comparison with MCNP6 shows good agreement. • Accurate energy deposition estimates for multi-physics calculations are now possible. - Abstract: In this work a new energy deposition treatment for the Serpent 2 Monte Carlo transport code is introduced. The treatment is implemented as a set of energy deposition modes, each of which offers a different combination of accuracy and required computational time. The most accurate mode uses the coupled neutron-photon transport available in Serpent 2. In addition to the new modes, a few other improvements such as a new energy deposition detector response was developed. The energy deposition treatment is demonstrated with simple LWR and LFR assembly level test cases. In the LWR cases the results are compared with MCNP6 on a high-level and a good agreement is achieved. In the LFR case differences in the energy deposition estimates of the different modes are highlighted. Based on the test cases, problems in the energy deposition data with ENDF/B-VII.1 and ENDF/B-VIII.0 are presented. Finally, future work concerning energy deposition capabilities of Serpent 2 are briefly discussed.