# Heat Source Characterization In A TREAT Fuel Particle Using Coupled Neutronics Binary Collision Monte-Carlo Calculations

## Abstract

This work presents a multi-physics, multi-scale approach to modeling the Transient Test Reactor (TREAT) currently prepared for restart at the Idaho National Laboratory. TREAT fuel is made up of microscopic fuel grains (r ˜ 20µm) dispersed in a graphite matrix. The novelty of this work is in coupling a binary collision Monte-Carlo (BCMC) model to the Finite Element based code Moose for solving a microsopic heat-conduction problem whose driving source is provided by the BCMC model tracking fission fragment energy deposition. This microscopic model is driven by a transient, engineering scale neutronics model coupled to an adiabatic heating model. The macroscopic model provides local power densities and neutron energy spectra to the microscpic model. Currently, no feedback from the microscopic to the macroscopic model is considered. TREAT transient 15 is used to exemplify the capabilities of the multi-physics, multi-scale model, and it is found that the average fuel grain temperature differs from the average graphite temperature by 80 K despite the low-power transient. The large temperature difference has strong implications on the Doppler feedback a potential LEU TREAT core would see, and it underpins the need for multi-physics, multi-scale modeling of a TREAT LEU core.

- Authors:

- Publication Date:

- Research Org.:
- Idaho National Lab. (INL), Idaho Falls, ID (United States)

- Sponsoring Org.:
- USDOE Office of Nuclear Energy (NE)

- OSTI Identifier:
- 1369423

- Report Number(s):
- INL/CON-16-40179

- DOE Contract Number:
- DE-AC07-05ID14517

- Resource Type:
- Conference

- Resource Relation:
- Conference: M&C 2017 International Conference on Mathematics & Computational Methods Applied to Nuclear Science & Engineering, Jeju, Republic of Korea (South Korea), April 16–20, 2017

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 97 MATHEMATICS AND COMPUTING; 36 MATERIALS SCIENCE; Binary Collision Monte-Carlo; Multiphysics; TREAT

### Citation Formats

```
Schunert, Sebastian, Schwen, Daniel, Ghassemi, Pedram, Baker, Benjamin, Zabriskie, Adam, Ortensi, Javier, Wang, Yaqi, Gleicher, Frederick, DeHart, Mark, and Martineau, Richard.
```*Heat Source Characterization In A TREAT Fuel Particle Using Coupled Neutronics Binary Collision Monte-Carlo Calculations*. United States: N. p., 2017.
Web.

```
Schunert, Sebastian, Schwen, Daniel, Ghassemi, Pedram, Baker, Benjamin, Zabriskie, Adam, Ortensi, Javier, Wang, Yaqi, Gleicher, Frederick, DeHart, Mark, & Martineau, Richard.
```*Heat Source Characterization In A TREAT Fuel Particle Using Coupled Neutronics Binary Collision Monte-Carlo Calculations*. United States.

```
Schunert, Sebastian, Schwen, Daniel, Ghassemi, Pedram, Baker, Benjamin, Zabriskie, Adam, Ortensi, Javier, Wang, Yaqi, Gleicher, Frederick, DeHart, Mark, and Martineau, Richard. Sat .
"Heat Source Characterization In A TREAT Fuel Particle Using Coupled Neutronics Binary Collision Monte-Carlo Calculations". United States.
doi:. https://www.osti.gov/servlets/purl/1369423.
```

```
@article{osti_1369423,
```

title = {Heat Source Characterization In A TREAT Fuel Particle Using Coupled Neutronics Binary Collision Monte-Carlo Calculations},

author = {Schunert, Sebastian and Schwen, Daniel and Ghassemi, Pedram and Baker, Benjamin and Zabriskie, Adam and Ortensi, Javier and Wang, Yaqi and Gleicher, Frederick and DeHart, Mark and Martineau, Richard},

abstractNote = {This work presents a multi-physics, multi-scale approach to modeling the Transient Test Reactor (TREAT) currently prepared for restart at the Idaho National Laboratory. TREAT fuel is made up of microscopic fuel grains (r ˜ 20µm) dispersed in a graphite matrix. The novelty of this work is in coupling a binary collision Monte-Carlo (BCMC) model to the Finite Element based code Moose for solving a microsopic heat-conduction problem whose driving source is provided by the BCMC model tracking fission fragment energy deposition. This microscopic model is driven by a transient, engineering scale neutronics model coupled to an adiabatic heating model. The macroscopic model provides local power densities and neutron energy spectra to the microscpic model. Currently, no feedback from the microscopic to the macroscopic model is considered. TREAT transient 15 is used to exemplify the capabilities of the multi-physics, multi-scale model, and it is found that the average fuel grain temperature differs from the average graphite temperature by 80 K despite the low-power transient. The large temperature difference has strong implications on the Doppler feedback a potential LEU TREAT core would see, and it underpins the need for multi-physics, multi-scale modeling of a TREAT LEU core.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {Sat Apr 01 00:00:00 EDT 2017},

month = {Sat Apr 01 00:00:00 EDT 2017}

}