As other questions (eg How large would the steam explosion at Chernobyl have been?) regarding that episode 2 of the Chernobyl series, the megaton estimate of the steam explosion looked very improbable to me.
My question is, as some atomic bombs (like Fat Man) are based on compression to obtain criticality: could the huge steam explosion generate so much pressure on the corium so that it makes it supercritical and generates a nuclear explosion?