%EJCT Card

This card is used for transient problems due to control rods insertion or withdrawal. This card is mandatory if calculation mode is RODEJECT.

%EJCT	Variable	Description	Remarks or examples
LINE 1	FBPOS(n)	Final bank n position after ejection and/or insertion (step)	Repeat this line NB times (NB = Number of CR bank)
	TMOVE(n)	When bank n starts move (second)
	BSPEED(n)	Bank n speed (steps/second)
LINE 2	TTOT	Total simulation time (seconds)	Example: 60. 0.1 40.0 1.0
	TSTEP1	First time step (seconds)
	TDIV	When to start second time step (seconds)
	TSTEP2	Second time step (seconds)
LINE 3	IBETA(1:6)	6-groups delayed neutron fraction	Not necessary if %XTAB card present
LINE 4	LAMB(1:6)	6-groups precursor decay constant	Not necessary if %XTAB card present
LINE 5	VELO(1:NG)	Neutron velocity	Not necessary if %XTAB card present

Note

You may need to reduce the time step size if the calculation is not stable. Typical time step size for thermal reactor calculations is in the order of millisecond.

Example:

! Rod ejection card
%EJCT
! Final Bank Pos (steps)     Starts Move (seconds)     Speed (steps/seconds)
     228.                     0.0                     2280.0    ! Bank 1     (LINE 1)
     0.                       0.0                     0.0       ! Bank 2
     0.                       0.0                     0.0       ! Bank 3
     228.                     0.0                     0.0       ! Bank 4
     0.                       0.0                     0.0       ! Bank 5
     0.                       0.0                     0.0       ! Bank 6
     0.                       0.0                     0.0       ! Bank 7
5.0 0.005  1.0  0.05            ! (seconds) total time, 1st time step, when to start 2nd time step, 2nd time step
0.0002584 0.00152 0.0013908 0.0030704 0.001102 0.0002584 !beta
0.0128  0.0318  0.119   0.3181  1.4027  3.9286           !decay constants
2.8E7    4.4E5     ! Neutron velocity