# BENCHMARK PROBLEM

#

# Identification: 11-A2 Source Situation ID.11

# Date Submitted: June 1976 By: R. R. Lee (CE)

# D. A. Menely (Ontario Hydro)

# B. Micheelsen (Riso-Denmark)

# D. R. Vondy (ORNL)

# M. R. Wagner (KWU)

# W. Werner (GRS-Munich)

#

# Date Accepted: June 1977 By: H. L. Dodds, Jr. (U. of Tenn.)

# M. V. Gregory (SRL)

#

# Descriptive Title: Two-dimensional LWR Problem,

# also 2D IAEA Benchmark Problem

#

# Reduction of Source Situation

# 1. Two-groupo diffusion theory

# 2. Two-dimensional (x,y)-geometry

#

PROBLEM neutron_diffusion 2D GROUPS 2

DEFAULT_ARGUMENT_VALUE 1 quarter # either quarter or eighth

READ_MESH 2dpwr-$1.msh

# define materials and cross sections according to the two-group constants

# each material corresponds to a physical entity in the geometry file

Bg2 = 0.8e-4 # axial geometric buckling in the z direction

MATERIAL fuel1 {

D1=1.5 Sigma_a1=0.010+D1(x,y)*Bg2 Sigma_s1.2=0.02

D2=0.4 Sigma_a2=0.080+D2(x,y)*Bg2 nuSigma_f2=0.135 }#eSigmaF_2 nuSigmaF_2(x,y) }

MATERIAL fuel2 {

D1=1.5 Sigma_a1=0.010+D1(x,y)*Bg2 Sigma_s1.2=0.02

D2=0.4 Sigma_a2=0.085+D2(x,y)*Bg2 nuSigma_f2=0.135 }#eSigmaF_2 nuSigmaF_2(x,y) }

MATERIAL fuel2rod {

D1=1.5 Sigma_a1=0.010+D1(x,y)*Bg2 Sigma_s1.2=0.02

D2=0.4 Sigma_a2=0.130+D2(x,y)*Bg2 nuSigma_f2=0.135 }#eSigmaF_2 nuSigmaF_2(x,y) }

MATERIAL reflector {

D1=2.0 Sigma_a1=0.000+D1(x,y)*Bg2 Sigma_s1.2=0.04

D2=0.3 Sigma_a2=0.010+D2(x,y)*Bg2 }

# define boundary conditions as requested by the problem

BC external vacuum=0.4692 # "external" is the name of the entity in the .geo

BC mirror mirror # the first mirror is the name, the second is the BC type

# # set the power setpoint equal to the volume of the core

# # (and set eSigmaF_2 = nuSigmaF_2 as above)

# power = 17700

SOLVE_PROBLEM # solve!

PRINT %.4f keff

WRITE_MESH $0-$1.vtu phi1 phi2 VECTOR NAME J1 Jx1 Jy2 0 VECTOR NAME J2 Jx2 Jy2 0