vgbe energy journal 10 (2022) - International Journal for Generation and Storage of Electricity and Heat

Analysis of VERA core physics benchmark problems
has a modular structure and offers multiple
solvers for the neutron transport equation
on 1D or 2D geometry with different boundary
conditions. DONJON5 employs diffusion
and SPn solution schemes [Hebert,
1987] with ability to handle detailed modeling
such as thermal-hydraulic feedback
through THM module. For lattice calculations,
scheme of Canbakan and Hebert 2015
is used. To produce improved multi-group
cross sections for core calculation, B1 leakage
including homogenization and condensation
procedure have been considered.
Two-step flux computation are carried out
using Method of Characteristics (MOC) on
detailed geometry instead of collision probability
method [Hebert, 2020] for fast calculations.
The self-shielding methods incorporated
as sub-group method as well as the
equivalence theory method [Lamarsh and
Baratta 2001].
DRAGON and DONJON computer codes
have been validated on different core configuration
including PWRs. BEAVRS benchmark-initial
core at Hot Zero Power (HZP)
conditions [Horelik, Herman et al. 2018].
For typical PWRs core configuration DRAG-
ON5 and DONJON5 have been applied to
find criticality, axial and radial power distributions
[Sukarno 2021]. To perform comparative
studies for conversion from high
enriched uranium (HEU) to low enriched
uranium (LEU) in the reactor MNSR using
DRAGON4 [Al Zain, El Hajjaji et al. 2018].
For the analyses of IAEA benchmark titled
in-core fuel management code package validation
for WWERs [Rooijen, Khan et al.
2017]. to perform burnup dependent analysis
of plate type research reactors [Liu, Wang
et al. 2015]. For the assessment in predicting
pin power reconstruction and form factors
as lattice code [Grgić, Ječmenica et al.
2012]. Validation to perform the fuel depletion
on UO2 pin cell for prediction of infinite
multiplication factor, isotopic inventories
and activities [Al Zain, El Hajjaji et al. 2021].
the effect of asymmetric assemblies and different
reflectors [Fröhlicher, Salino et al.
2021], Nuclear Heat Reactor NHR-5 [El
Yaakoubi, Boukhal et al. 2021] are studied
earlier to benchmark or validate the codes
for various problem scenarios. To validate
DRAGON5 and DONJON5 computer codes
for application on PWRs from pin cell to core
configurations including different burnable
poison rods, Virtual Environment for Reactor
Applications (VERA) core physics benchmark
set of problems provides an excellent
reference.
The VERA Benchmark [Godfrey 2014] consists
of a series of Core Physics Progression
problems for Pressurized Water Reactor.
The VERA benchmarks comprise of the twodimensional
(2-D) pin cell problems at fixed
temperature, various 2-D lattice assembly
for different configurations as well as initial
startup core i.e., Hot Zero Power (HZP)
quarter core problem and three-dimensional
(3-D) hot full power (HFP) core depletion
problem. The benchmarks were proposed by
the Consortium for Advanced Simulation of
Light water reactors (CASL) to assist nuclear
software and methods developers and analysts
in assessing capabilities needed to
model LWR cores. In addition to problem
specification, reference solutions by continuous
energy Monte Carlo code KENO-VI are
also provided.
2 Computer codes
In this study for pin cell and fuel assembly
lattice calculation the DRAGON5 and for
core calculation the DONJON5 code is used.
The calculations have been performed at
Hot Zero Power operating conditions with
multi-group cross-sections (XSs) libraries
based on ENDF/B-VII.0.
2.1 DRAGON5
28 1 group Multi-group
Library (DRAGLIB)
Self-Shielded
Library
Next Bum up Step
USS:
FLU:
Multi cell Flux
Calculation
Energy
Condensation
(26 groups)
2 nd Level MOC
Flux Calculation
Condensation (2 groups)
Fuel Burn up
Database (COMPO)
Micro Lib Updated for
1 st Level
Fig. 1. Flow chart of calculation procedure.
The lattice code DRAGON5 is a deterministic
lattice computer code to solve the neutron
transport equation using collision probability
(CP) as well as Method of Characteristics
(MOC) to generate few-group
constants for later use in core calculations.
The DRAGON5 computer code consists
of a set of modules connected through
the GAN generalized driver Branch calculations
for moderator temperature, fuel
temperature, moderator density, boron concentration,
burnup and control variations
to accommodate the various core conditions.
DRAGON5 lattice computer code performs
the multi-dimensional, multi-group resonance
self-shielding calculations and neutron
flux calculations considering the neutron
leakage. It also performs transporttransport
or transport-diffusion calculations
and isotopic depletion calculations
[G, Hébert et al. 2021].
2.2 DONJON5
DONJON5 is a modular deterministic code
used for 3-dimensional core calculation developed
by École Polytechnique de Montréal
in Canada. The DONJON5 computer code
consists of a set of modules connected
through the GAN generalized driver [Roy
and Hébert 2000]. It solves the neutron diffusion
equations in few groups for core cal-
FLU:
Tracking
Tracking
Tracking
Simple
Geometry
Level1
Geometry
Level2
Geometry
vgbe energy journal 10 · 2022 | 55