  Possible occurrence of an equilibrium thermodynamic phase with a
spontaneously broken time-reversal symmetry is studied in a model ceramic
superconductor with anisotropic pairing symmetry. It is shown by Monte Carlo
simulations that such a ``chiral-glass'' phase is truly stable even under the
influence of screening. Existence of frustration in zero external field,
arising from the d-wave pairing symmetry of high-T_c superconductors, is
essential to realize this phase. Via a finite-size scaling analysis, critical
exponents associated with the chiral-glass transition are estimated to be \nu
_CG=1.3\pm 0.2 and \eta _CG=-0.2\pm 0.2. These values turn out to be close to
those of the Ising spin glass. Phase diagram of the model is constructed and
the implications to experiments are discussed.
