Gravitational radiation is a fundamental prediction of General Relativity. Elliptically deformed pulsars are among the possible sources emitting gravitational waves (GWs) with a strain-amplitude dependent upon the stars quadrupole moment, rotational
frequency, and distance from the detector. We show that the gravitational wave strain amplitude $h_0$ depends strongly on the equation of state of neutron-rich stellar matter. Applying an equation of state with symmetry energy constrained by recent nuclear laboratory data, we set an upper limit on the strain-amplitude of GWs produced by elliptically deformed pulsars. Depending on details of the EOS, for several millisecond pulsars at distances $0.18kpc$ to $0.35kpc$ from Earth, the {it maximal} $h_0$ is found to be in the range of $sim[0.4-1.5]times 10^{-24}$. This prediction serves as the first {it direct} nuclear constraint on the gravitational radiation. Its implications are discussed.
