This page is the beginning of a hands-on tutorial in Serpent that will walk you through the creation of simple pin-cell and assembly geometry models and the use of those models for some reactor physics simulations.
Pre-requisite
Compiled version of Serpent 2
Basics of Serpent input
Explain different (typical) parts such as:
- Material definitions
- Geometry definitions
- Run parameters/options
Infinite homogeneous model
Overview
The first model in this tutorial is the simplest geometry model one can imagine: an infinite homogeneous system consisting of a single material. Here the infinite material is 4.0 wt-% enriched uranium with a density of 10.1 g/cm3.
We will use the infinite homogeneous system example for three tasks:
- Finding the critical enrichment of an infinite uranium system.
- Tallying the neutron energy spectrum in the critical infinite uranium system.
- Testing the effect of added neutron moderation on the multiplication factor and energy spectrum of the system.
The input of such a model consists of
- Defining the single material, which is called fuel in this example.
- Defining the geometry by
- Defining an "infinite" surface, i.e. a surface enclosing all of space. The surface name is s1 in this example.
- Defining two geometry cells: One containing the material fuel and the other being defined as an outside cell.
- Setting up other run parameters, here simply setting the neutron population that is to be simulated.
Input
Colors in the input correspond to:
- Comments
- Control words
- Name definitions
- Name references
Input for 2D pin-cell geometry
% --- Very simple infinite homogeneous geometry for Serpent tutorial
/************************
* Material definitions *
************************/
% --- Fuel material (4.0 wt-% enriched uranium dioxide), density 10.1 g/cm3
mat fuel -10.1
92235.03c -0.04
92238.03c -0.96
/************************
* Geometry definitions *
************************/
% --- "Surface" at infinity
surf s1 inf
% --- Cell c1 belongs to the base universe 0, contains the material fuel
% and covers everything inside surface s1
cell c1 0 fuel -s1
% --- Cell c2 belongs to the base universe 0, is defined as an "outside" cell
% and covers everything outside surface s1
cell c2 0 outside s1
/******************
* Run parameters *
******************/
% --- Neutron population: 5000 neutrons per cycle, 100 active / 20 inactive cycles
set pop 5000 100 20
Testing and tinkering
2D Pin-cell model
Overview
Basics
Colors in input correspond to:
- Comments
- Control words
- Name definitions
- Name references
Input for 2D pin-cell geometry
% --- Simple 2D PWR pin-cell geometry for Serpent tutorial
/************************
* Material definitions *
************************/
% --- Fuel material (3.0 wt-% enriched uranium dioxide), density 10.1 g/cm3
mat fuel -10.1
92235.03c -0.02644492
92238.03c -0.85505247
8016.03c -0.11850261
% --- Cladding material for fuel rod
% (100 % Zirconium)
mat clad -6.55
40000.03c -1.0
% --- Water at 1.0 g/cm3
mat water -1.0
1001.03c 2.0
8016.03c 1.0
/************************
* Geometry definitions *
************************/
% --- Fuel pin structure
pin p1
fuel 0.4025
clad 0.4750
water
% --- Square surface with 1.0 cm side centered at (x,y) = (0,0)
surf s1 sqc 0.0 0.0 0.5
% --- Cell c1 belongs to the base universe 0, is filled with the pin p1
% and covers everything inside surface s1
cell c1 0 fill p1 -s1
% --- Cell c2 belongs to the base universe 0, is defined as an "outside" cell
% and covers everything inside surface s1
cell c2 0 outside s1
/******************
* Run parameters *
******************/
% --- Neutron population
set pop 5000 100 20
% --- Boundary condition (1 = black, 2 = reflective, 3 = periodic)
set bc 2
% --- Geometry plots
plot 3 200 200
plot 3 1000 1000 0.0 -2.5 2.5 -2.5 2.5
Testing and tinkering
2D Assembly model
Overview
Basics
Testing and tinkering
