The introduction of tritium into the cavity of C-60 using hot-atom chemistry was studied. Neutron irradiation of He-3 in He-3@C-60 produced tritium ions and atoms which enter the C-60 H-3@C-60 was detected with a scintillation counter. The Bingel reaction was carried out on this material under conditions so that the monoadduct formed predominantly, and the products were probed for tritium activity. Analysis with He-3 NMR gave a peak with the characteristic He-3 shift for the malonate product. The product fractions gave only 33% of the original activity; most was recovered in the unreacted C-60 portion, No reaction was observed between C-60 and the stable radical di-tert-butylnitroxide; all tritium activity was recovered in the Coo peak. These results suggest similarities in properties between H-3@C-60 and pure C-60, implying that the tritium exists as a free atom inside the molecule.