Parity nonconservation due to the nuclear weak charge is considered. We demonstrate that the radiative corrections to this effect due to the vacuum fluctuations of the characteristic size larger than the nuclear radius r_0 and smaller than the electron Compton wave-length λ_C are enhanced because of the strong electric field of the nucleus. The parameter that allows one to classify the corrections is the large logarithm (λ_C/r_0). The vacuum polarization contribution is enhanced by the second

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... wer of the logarithm. Although the self-energy and the vertex corrections do not vanish, they contain only the first power of the logarithm. The value of the radiative correction is 0.4 correction affects the interpretation of the experimental data on parity nonconservation in atoms.