This keyword is an alternative to ATOMS. It suppresses the inventory output, so that only the γ spectrum and total values are printed for the time interval. It is useful if summary information is required for many time intervals, but the details of the individual nuclide contributions are not needed. This keyword may also be used in the initial and/or inventory section(s) of the input file and can be interchanged with ATOMS or STEP throughout a simulation.
Note that without using ATOMS, SPECTRUM, or STEP after each time interval, the rate equations will not be solved. Omission of these keywords will not result in an error and calculations will run, but the results will not be as expected.
< -- Control phase -- > ... FISPACT * Title of the simulation < -- Initial phase -- > ... FLUX 1.0E10 SPECTRUM < -- Inventory phase -- > TIME 1.0 HOURS SPECTRUM TIME 1.0 HOURS SPECTRUM TIME 1.0 HOURS ATOMS TIME 1.0 HOURS SPECTRUM ATOMS ...