Kraken SMR progression problem

The core consists of 37 fuel assemblies as in the NuScale reactor. Each assembly includes 264 fuel rods, 24 guidetubes and an instrumentation tube. Assembly radial geometries are based on the BEAVRS benchmark. With the exception of the active fuel length, which is reduced from 365 cm to 200 cm, the axial geometry is based on BEAVRS.

A total of five different fuel enrichments are included in the core: 1.6 wt-%, 2.4 wt-%, 3.1 wt-%, 3.2 wt-% and 3.4 wt-% enriched uranium. The arrangement of the fuel assemblies by fuel enrichment is designed to produce as uniform radial power distribution as possible. Borosilicate glass burnable absorbers are placed in several assemblies to minimize assembly power peaking.

The control rod geometry is based on the BEAVRS benchmark with reduced length. Control rods consist of two parts of absorbing material. The lower part is Ag-In-Cd-alloy (silver-indium-cadmium) and the top part is boron carbide (B4C). A CRA consists of 16 control rods. CRAs are divided into two banks: a Regulating Bank (RB) and a Shutdown Bank (SB). The regulating bank can be used during operation to adjust the power level, whereas the shutdown bank is used for shutdown only. Each bank consists of eight individually movable CRAs.

Input files

All files as a compressed folder: File:SMR progression Serpent.gz

main input file

/***************************************
 * Input file for SMR demo for Serpent *
 ***************************************/

% Fuel assemblies based on BEAVRS Benchmark rev. 2.0.2
% Active fuel length limited to 200cm as per the NuScale specifications.


include "./includes/materials.inc"

include "./includes/surfaces.inc"

include "./includes/fuelrod.inc"
include "./includes/guidetube.inc"
include "./includes/instrumenttube.inc"
include "./includes/BP.inc"

include "./includes/grid.inc"

include "./includes/assembly_lattices_R.inc"
include "./includes/assembly_universes_R.inc"
include "./includes/assembly_lattices_Y.inc"
include "./includes/assembly_universes_Y.inc"
include "./includes/assembly_lattices_B.inc"
include "./includes/assembly_universes_B.inc"
include "./includes/assembly_lattices_G.inc"
include "./includes/assembly_universes_G.inc"
include "./includes/assembly_lattices_O.inc"
include "./includes/assembly_universes_O.inc"

include "./includes/core.inc"

include "./includes/controlrod.inc"
include "./includes/reflector.inc"

include "./includes/options.inc"

% --- Choose state from here

include "./includes/state_czp.inc"
%include "./includes/state_hzp.inc"
%include "./includes/state_hfp.inc"

%%%%%%
%%%%%%

% --- Truncated cylinder as the outer boundary of the model
%     Diameter (9 feet, RPV approximate inner diameter NuScale
%               Licensing documents Part 2 1.2.1.1.2)

surf sCylinder  cylz 0.0 0.0 137.16 -45 265

% Cell cIN contains reactor

cell cIN    0 fill reactor  -sCylinder

% Cell cOUT is defined as an outside cell

cell cOUT   0 outside        sCylinder

% --- Transformation for the control rod movement
%     The values given are transformations in (x, y, z)
%     Transformation of 0.0 means fully inserted.
%     Transformation of 194.920 means withdrawn.
%     Step height is 0.8549cm and there are 228 steps.
%
%     If either of the control rod banks R or S are withdrawn, single assemblies of that bank can
%     be inserted by setting a negative z-coordinate (-194.920 for fully inserted).

trans u R1 0.0 0.0 0.0
trans u R2 0.0 0.0 0.0
trans u R3 0.0 0.0 0.0
trans u R4 0.0 0.0 0.0
trans u R5 0.0 0.0 0.0
trans u R6 0.0 0.0 0.0
trans u R7 0.0 0.0 0.0
trans u R8 0.0 0.0 0.0
trans u S1 0.0 0.0 0.0
trans u S2 0.0 0.0 0.0
trans u S3 0.0 0.0 0.0
trans u S4 0.0 0.0 0.0
trans u S5 0.0 0.0 0.0
trans u S6 0.0 0.0 0.0
trans u S7 0.0 0.0 0.0
trans u S8 0.0 0.0 0.0
trans u R  0.0 0.0 194.920
trans u S  0.0 0.0 194.920


% Geometry plots

% --- XY-plot
% --- XZ-plot
% --- YZ-plot

plot 3 1000 1000 60 -100 100 -100 100
plot 2 1000 1000 0 -100 100 -45 265
plot 1 1000 1000 21.50364 -100 100 -45 265

/*
plot 3 5000 5000 60 -100 100 -100 100
plot 2 5000 5000 0 -100 100 -45 265
plot 1 5000 5000 21.50364 -100 100 -45 265
*/

% --- Meshplot

mesh 3 1000 1000