  We investigate the two-proton capture reaction of the prominent rapid proton
capture waiting point nucleus, $^{68}$Se, that produces the borromean nucleus
$^{70}$Kr ($^{68}$Se$+p+p$). We apply a recently formulated general model where
the core nucleus, $^{68}$Se, is treated in the mean-field approximation and the
three-body problem of the two valence protons and the core is solved exactly.
The same Skyrme interaction is used to find core-nucleon and core
valence-proton interactions. We calculate $E2$ electromagnetic two-proton
dissociation and capture cross sections, and derive the temperature dependent
capture rates. We vary the unknown $2^+$ resonance energy without changing any
of the structures computed self-consistently for both core and valence
particles. We find rates increasing quickly with temperature below $2-4$~GK
after which we find rates varying by less than a factor of two independent of
$2^+$ resonance energy. The capture mechanism is sequential through the
$f_{5/2}$ proton-core resonance, but the continuum background contributes
significantly.
