26 C.F.R. § 1.678(d)-1
Renunciation of power
Section 678(a) does not apply to a power which has been renounced or disclaimed within a reasonable time after the holder of the power first became aware of its existence.
Section 678(a) does not apply to a power which has been renounced or disclaimed within a reasonable time after the holder of the power first became aware of its existence.