The work that has been done in compound nucleus studies of time-reversal-noninvariant (TRNI), parity-conserving (PC) NN interactions is reviewed. The general form of TRNI PC meson-exchange potentials that can be constrained by such studies is discussed a la Simonius. The competing limits that can be obtained from atomic electric dipole moments produced by weak radiative corrections to long-ranged TRNI PNC interactions are then explored. Both classes of constraints limit the magnitude of typical TRNI PC matrix elements to about 10{sup {minus}3} of those for strong interactions. These limits are contrasted with those recently obtained from short-ranged one- and two-loop weak radiative corrections
