  We propose a technique to effectively sample initial neutron and delayed
neutron precursor particles for Monte Carlo (MC) simulations of typical
off-critical reactor transients. The technique can be seen as an improvement,
or alternative, to the existing ones. Similar to some existing techniques, the
proposed sampling technique uses the standard MC criticality calculation.
However, different from the others, the technique effectively produces
uniform-weight particles around user-specified target sizes. The technique is
implemented into the open-source Python-based MC code MC/DC and verified
against an infinite homogeneous 361-group medium problem and the 3D C5G7-TD
benchmark model.
