  Thermonuclear runaways driven by accretion into degenerate white dwarf cores
are the source that power classical nova outbursts.
  In this paper, we identify the dominant nuclear paths involved in the
synthesis of intermediate-mass elements, from Si to Ca, during such violent
events.
  New evolutionary sequences of 1.35 Mo ONe novae have been computed, using
updated nuclear reaction rates.
  The main nuclear activity in this region is powered by the leakage from the
NeNa-MgAl region, where the activity is confined during the early stages of the
explosion. We discuss the critical role played by 30P(p,gamma) in the synthesis
of nuclear species beyond sulfur and point out the large uncertainty that
affects its rate, which has dramatic consequences for studies of nova
nucleosynthesis in the Si-Ca mass region.
