The Woodruff School

SUMMARY

Fluoride High Temperature Reactors (FHRs) are envisioned to be next generation reactors due to their inherent safety design characteristics and high efficiency due to use of salt based coolants. FHRs use Tri-Isotropic structural (TRISO) fuel due to its benefits of encapturing fission gases and fission products in its layers. One of the main disadvantages of using TRISO fuel is that its production costs are a lot higher (in range of $5,000-$30,000 per kg Uranium) compared to current pellet based fuel ($200 per kg Uranium). In this study, we propose and develop a spectral shift method to operate this type of reactors. This spectral shift method is based on varying neutron energy spectrum. As a result, both cycle length and discharge burnup are improved simultaneously while eliminating the need of burnable poison.

SUBJECT:	M.S. Thesis Presentation

BY:	Vedant Mehta

TIME:	Friday, November 30, 2018, 1:00 p.m.

PLACE:	Boggs, 3-47

TITLE:	Spectral Shift Operated SmAHTR to Improve Cycle Length and Discharge Burnup Simultaneously

COMMITTEE:	Dr. Dan Kotlyar, Chair (NRE) Dr. Bojan Petrovic (NRE) Dr. Chaitanya Deo (NRE)

SUMMARY Fluoride High Temperature Reactors (FHRs) are envisioned to be next generation reactors due to their inherent safety design characteristics and high efficiency due to use of salt based coolants. FHRs use Tri-Isotropic structural (TRISO) fuel due to its benefits of encapturing fission gases and fission products in its layers. One of the main disadvantages of using TRISO fuel is that its production costs are a lot higher (in range of $5,000-$30,000 per kg Uranium) compared to current pellet based fuel ($200 per kg Uranium). In this study, we propose and develop a spectral shift method to operate this type of reactors. This spectral shift method is based on varying neutron energy spectrum. As a result, both cycle length and discharge burnup are improved simultaneously while eliminating the need of burnable poison.