In presenta paper

the interference between Sm and U in non-destructive neutron activation analysis has been studied. When the radioactivities of

153

Sm and

239

Np are close to each other

the 103.2keV photopeak of

153

Sm and the 103.7keV photopeak of

239

Np (

239

Pu) do not appear correctly if the single-peak analysis is used. It seriously interfered the accurate measurement of Sm. The overlapping-peak-analysis program designed by our laboratory can be used to obtain the mixture of these two peaks. We use the stripping method. i. e. after stripping the spectrum of pure uranium

the mixed

γ

spectrum of Sm and U go through the single-peak or overlapping-peak analysis. By this way

we can get the pure 103.2keV photopeak of

153

Sm quite accurately. The stripping method can be used to strip the contributions of all the fission products of uranium. This also is the one of its advantages. The stripping method may have other applications in non-destructive neutron activation analysis.