Definitions
- ZA defines the element and isotope as:
1000 
Z + A
where Z is the proton number and A is the mass number. For example, the ZA for U-235 is 92235.
Units
| Quantity
|
Unit
|
Notes
|
| Distance
|
cm
|
|
| Area
|
cm2
|
|
| Volume
|
cm3
|
|
| Time
|
s
|
depends on the case
|
| Energy
|
MeV
|
|
| Microscopic cross section
|
b
|
barn = 10-24 cm2
|
| Macroscopic cross section
|
1/cm
|
|
| Mass
|
g
|
|
| Mass density
|
g/cm3
|
|
| Atomic density
|
1024/cm3
|
( = b-1cm-1)
|
| Power
|
W
|
|
| Power density
|
kW/g
|
|
| Particle flux
|
1/cm2s
|
|
| Reaction rate
|
1/cm3s
|
reaction rate density
|
| Burnup
|
MWd/kgU
|
per total initial heavy metal
|
| Burn time
|
days
|
|
Constants
| Constant
|
Value
|
Units
|
Notes
|
| INFTY
|
1037
|
N/A
|
Used to denote infinity
|
| ZERO
|
10-37
|
N/A
|
The smallest nonzero absolute value
|
