WIMS Library Update Project 
Burnup benchmarks
D2Omoderated
uranium oxide lattices.
Analysis of Isotopic Composition as function of burnup
Laboratory: AECL Atomic Energy of Canada Limited (Canada)
Facility: NPD Nuclear Power Demonstration reactor
NPD is a Canadian demonstration PHWR (25 MW electrical power) shut
down on 1987. The moderator and coolant were heavy water. The fuel
was in the form of 19 natural UO2 rod CANDU type clusters.
Isotopic measurements of irradiated 19 element fuel bundles
have been done
in 1971 at the CEA in France. The measurements included a series of eight
bundles with irradiation in the range 100010000 MWd/TU which were analysed
by massspectroscopy.
Pitch (cm)  26.035 (square) 
Coolants  D2O 
Moderator  D2O 
Number of rods  19 (1/6/12) 
Radius of rod centers (cm)  0.0/1.65/3.18755 
Angular dist.from reference axis (radians)  0.0/0.0/0.2617994 
Fuel material  UO2nat 
Density of fuel material (g/cm^{2})  10.0704 
Radius of fuel rods (cm)  0.71247 
Sheath material  Zry2 
Density of sheath material (g/cm3)  6.57 
Internal radius of sheath (cm)  0.71505 
Thickness of sheath (cm)  0.04191 
Material of pressure tube  Zry2 
Density of pressure Tube (g/cm3)  6.556 
Internal radius of pressure tube (cm)  4.1402 
Thickness of pressure tube (cm)  0.4318 
Material of calandria tube  57S Al alloy 
Density of calandria Tube (g/cm3)  2.68 
Internal radius of calandria tube (cm)  5.08 
Thickness of calandria tube (cm)  0.12827 
Effective fuel Temperature (K)  778.2 
Effective coolant Temperature (K)  531.7 
Temperature of moderator (K)  311.0 
Experimental buckling (1/cm^{2})  0.000173 
2) NEA Burnup Credit Criticality Benchmark
LWRBurnup credit criticality benchmark. Isotopic composition prediction
Laboratory: Pacific Northwest Laboratory, Richland, Washington (USA)
Facility: ATM104 Approved Testing Material, Combustion Engineering (CE) 14x14This benchmark compares the computed nuclide inventories for a simple pin cell
calculation. The fuel and operating specifications are based on data given
in the references for the Combustion Engineering (CE) 14 x 14 assembly designated
as Approved Testing Material ATM104, for a series of experiments designed to
characterize spent fuel for light water reactors. The chemical assay data measured
in these experiments are of particular value in validating the isotopic predictions
used
in burnup credit.
Data
Cell radius (cm)  0.879346 
Moderator  H2O 
Moderator Density (g/cm^{3})  0.7569 
Moderator Temperature (K)  558 
Fuel material  UO2 (3% at. U235 enrichment) 
Density of fuel material (g/cm^{3})  10.045 
Effective fuel Temperature (K)  841 
Radius of fuel rods (cm)  0.47815 
Clad material  Zry2 
Density of clad material (g/cm^{3})  6.55 
Internal radius of clad (cm)  0.493 
Thickness of clad (cm)  0.066 
Clad Temperature (K)  620 
Cycle
1 avg boron concentration (ppm) 
331 
Operating history data for isotopic calculation
OPERATING CYCLE  BURN
[days] 
DOWN
[days] 
BORON [% cycle 1] 
1  306.0  71.0  100.0 
2  381.7  83.1  141.9 
3  466.0  85.0  152.3 
4  461.1  1870.0  148.8 
BURN is the fuel irradiation time
DOWN is the downtime between
cycles except for cycle 4 where it
includes the decay time from reactor to measurement (cooling time)
BORON is the cycleaverage
boron concentration as a percent of
the cycle 1 concentration
Specific power
OPERATING CYCLE 
Specific
Power [Kw/kgU] 

Sample 1  Sample 2  Sample 3  
1  17.24  24.72  31.12 
2  19.43  26.76  32.51 
3  17.04  22.84  26.20 
4  14.57  18.87  22.12 
Cumulative Burnup [GWd/MTU] 
27.35  37.12  44.34 
Initial fuel number densities
Nuclide  Number
Density atoms/(barn.cm) 
U234  6.15165E06 
U235  6.89220E04 
U236  3.16265E06 
U238  2.17104E02 
C12  9.13357E06 
N14  1.04072E05 
O  4.48178E02 
Cycle 1 coolant number densities
Nuclide  Number
Density atoms/(barn.cm) 
H1  5.06153E02 
O16  2.53076E02 
B10  2.75612E06 
B11  1.11890E05 
LWRPu
recycling benchmarks
These numerical benchmarks compare the computed nuclide inventories for simple
pin
cell calculations, for two cases:
A) highly degraded plutonium, and
B) normal recycled plutonium.
Reference results Isotopic concentrations (mg/g fuel) on the fuel pin for:
U234, U235,U236, U238, Np237, Pu238, Pu239, Pu240,
Pu241,Pu242, Am241,
Am242m,Am243, Cm242, Cm243, Cm244, Cm245, Mo95, Tc99, Ru101,
Rh103,
Pd105, Pd107,Pd108, Ag109, Xe131, Xe135, Cs133, Cs135, Nd143, Nd145, Pm147,
Pm148m,Sm149, Sm150, Sm151, Sm152, Eu153, Eu154, Eu155,
for cases A and B, at 50 GWd/MTU burnup.
Calculated ParametersIsotopic
concentrations (mg/g fuel) on the fuel pin for:
U234, U235,
U236, U238, Np237, Pu238, Pu239, Pu240, Pu241,Pu242, Am241,
Am242m, Am243, Cm242, Cm243, Cm244, Mo95,
Tc99, Ru101, Rh103, Pd105,
Pd107, Pd108, Ag109, Xe131, Xe135, Cs133, Cs135, Nd143, Nd145, Pm147,
Pm148m, Sm149, Sm150, Sm151, Sm152, Eu153,Eu154, Eu155
for cases A and B, at 50 GWd/MTU burnup.
Data
Pitch (cm) 
1.3133 (square) 
Moderator 
H2O(+Bnat) 
579 

Fuel material 
UO2PuO2 
Effective fuel Temperature (K) 
933 
Radius of fuel rods (cm) 
0.4095 
Clad material 
Zr 
0.043248 

Radius of clad (cm) 
0.4750 
Clad Temperature (K) 
579 
Nuclide

Number
Density
atoms/(barn.cm) 

A

B


U234



2.4626E07

U235

1.4456E04

5.1515E05

U238

1.9939E02

2.0295E02

Pu238

1.1467E04

2.1800E05

Pu239

1.0285E03

7.1155E04

Pu240

7.9657E04

2.7623E04

Pu241

3.3997E04

1.4591E04

Pu242

5.6388E04

4.7643E05

O

4.5851E02

4.3100E02

Nuclide  Number
Density atoms/(barn.cm) 
H1  4.7716E02 
O16  2.3858E02 
Bnat  1.98606E05 