  Standard stellar evolution models that only consider convection as a physical
process to mix material inside of stars predict the production of significant
amounts of 3He in low-mass stars (M < 2 Msun), with peak abundances of 3He/H ~
few x 10-3 by number. Over the life-time of the Galaxy, this ought to produce
3He/H abundances that diminish with increasing Galactocentric radius.
Observations of 3He+ in HII regions throughout the Galactic disk, however,
reveal very little variation in the 3He abundance with values of 3He/H similar
to the primoridal abundance, (3He/H)p ~ 10-5 . This discrepancy, known as the
"3He Problem", can be resolved by invoking in stellar evolution models an
extra-mixing mechanism due to the thermohaline instability. Here, we observe
3He+ in the planetary nebula J320 (PN G190.3-17.7) with the Jansky Very Large
Array (JVLA) to confirm a previous 3He+ detection made with the VLA that
supports standard stellar yields. This measurement alone indicates that not all
stars undergo extra mixing. Our more sensitive observations do not detect 3He+
emission from J320 with an RMS noise of 58.8 microJy/beam after smoothing the
data to a velocity resolution of 11.4 km/s . We estimate an abundance limit of
3He/H <= 2.75 x 10-3 by number using the numerical radiative transfer code
NEBULA. This result nullifies the last significant detection of 3He+ in a PN
and allows for the possibility that all stars undergo extra mixing processes.
