  A non-destructive, gamma-spectrometric method for uranium age-dating is
presented which is applicable to material of any physical form and geometrical
shape. It relies on measuring the daughter/parent activity ratio 214Bi/234U by
low-background, high-resolution gamma-spectrometry using intrinsic efficiency
calibration. The method does not require the use of any reference materials nor
the use of an efficiency calibrated geometry.
