Galactic evolution of D and He-3 including stellar production of He-3

New stellar models which track the production and destruction of He-3 (and D) have been evolved for a range of stellar masses (0.65 less than or equal to M/M. less than or equal to 100), metallicities (0.01 less than or equal to Z/Z. less than or equal to 1), and initial (main-sequence) He-3 mass fractions (10(-5) less than or equal to X(3,MS) less than or equal to 10(-3)). Armed with the He-3 yields from these stellar models we have followed the evolution of D and He-3 using a variety of chemical evolution models with and without infall of primordial or processed material. Production of new He-3 by the lower mass stars overwhelms any reasonable primordial contributions and leads to predicted abundances in the presolar nebula and/or the present interstellar medium in excess of the observationally inferred values. This result, which obtains even for zero primordial D and He-3, and was anticipated by Rood, Steigman, & Tinsley is insensitive to the choice of chemical evolution model; it is driven by the large He-3 yields from low-mass stars. In an attempt to ameliorate this problem we have considered a number of nonstandard models in which the yields from low-mass stars have been modified. Although several of these nonstandard models may be consistent with the He-3 data, they may be inconsistent with observations of C-12/C-13, O-18, and, most seriously, the super-He-3 rich planetary nebulae. Even using the most extreme of these nonstandard models we obtain a generous upper bound to pregalactic He-3: X(3P) less than or equal to 3.2 x 10(-5) which, nonetheless, leads to a stringent lower bound to the universal density of nucleons.