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= 2 Information for debugging
= 3 Detailed information for debugging
IBC5
Definition of instantaneous conversion ratio
= 0 Use defaulted definition of conversion ratio
= 1 Conversion ratio is redefined by entries of Block-7-1 through -7-3
Note:
Generally, an instantaneous conversion ratio is defined as the ratio of
production rate to depletion rate of fissile nuclides as follows:
FISSProduction( t)
Instantaneous CR( t ) = . (2.11-1)
FISSDepletion( t)
In the SRAC, the user can flexibly define the numerator and denominator of
Eq.(2.11-1). They are calculated by Eqs.(2.11-2) and (2.11-3), respectively. (Both
are the same function forms)
⎡
⎤
i i i
i i i
∫ ⎢∑ ∑{ α < N ( t)
> σ x(
i g ( t)
Φ g ( t)
+ β λ N } ⎥ dV
FISSP ( t)
=
),
⎢⎣
g i∈Specified
⎥⎦
(2.11-2)
⎡
FISSD ( t)
= ∫ ⎢∑ ∑
x(
j),
⎢⎣
g j∈Specified
⎤
j j j
j j j
{ α < N ( t)
> σ ( t)
Φ ( t)
+ β λ N } ⎥ dV
g
g
⎥⎦
(2.11-3)
where,
i , j : any nuclides selected from the burn-up chain library used,
α , β : arbitrary factors defined by user, which are used to consider
branching ratio or to cut of unnecessary terms (e.g. β = 0.0),
< N i > : atomic number density of nuclide i or 1.0 to define microscopic
reaction rate,
i
x ( i)
σ : microscopic cross-section of nuclide i for reaction type x. The
reaction type is determined by user depending on nuclide i,
λ : decay constant of each nuclide whose value is defined in the
burn-up chain library. (cf. Sect.3.3)
Furthermore, integrated conversion ratio is also calculated as follows:
137