  Rapid neutron-capture (i.e., r-process) nucleosynthesis calculations,
employing internally consistent and physically realistic nuclear physics input
(QRPA beta-decay rates and the ETFSI-Q nuclear mass model), have been made.
These calculations are compared with ground-based and HST observations of
neutron-capture elements in the metal poor halo stars CS 22892--052, HD 115444,
HD 122563 and HD 126238. The elemental abundances in all four metal-poor stars
are consistent with the solar r-process elemental distribution for the elements
Z >/= 56. These results strongly suggest, at least for those elements, that the
relative elemental r-process abundances have not changed over the history of
the Galaxy. This further suggests that there is one r-process site in the
Galaxy, at least for elements Z >/= 56.
  Employing the observed stellar abundances of stable elements, in conjunction
with the solar r-process abundances to constrain the calculations, predictions
for the zero decay-age abundances of the radioactive elements Th and U are
made. We compare these (least-squares-fit ETFSI-Q) predictions with newly
derived observational values in three very metal-poor halo stars: HD 115444, CS
22892--052 and HD 122563. Within the observational errors the observed ratio of
[Th/Eu] is the same in both CS 22892--052 and HD 115444. Comparing with the
theoretical ratio suggests an average age of these two very metal poor stars to
be approximately 15.6 +/- 4.6 Gyr, consistent with earlier radioactive age
estimates and recent globular and cosmological age estimates.
