SAFPWR home page
Total MSLB accident: effect of delayed neutron fraction

In fast reactivity accidents, a low beta value is, in general, adverse, because it causes prompt criticality to be reached earlier.
Take here (rtvsym_4.dat) core / Lstgg / beg= .005 vs reference .0076.
A low beta value is characteristic of mox fuel.

We observe (chart 01 to chart 05) that rc peaks now at .005, as expected.
max q2c is higher (850e6|750e6) but u2c7 peak (chart 03) is lower (850|900 K), which is more surprising!
This could perhaps be explained by the earlier action of feedback's.

Could we conclude that a low (MOX) beta value has no adverse effect on mslb safety margins; on the contrary?