Immobilisation of Higher Activity Wastes from Nuclear Reactor Production of ⁹⁹Mo

Table 3

Approximate composition (wt%) and half-lives^& of main fission product and actinide oxides in PUREX fuel reprocessing HLW that has been stored for >10 years.

Fission product oxide Basis (wt%)^$	Half-life of most abundant radioisotope (y)	Fission product oxide Basis (wt%)^$	Half-life of most abundant radioisotope (y)
Cs2O (6)	30	TcO2 (6)	210000
SrO (3)	30	*AnO2 (6)	>10000
BaO (4)	—	RuO2 (10)	—
RE2O3 (15)	100^&	PdO (6)	—
ZrO2 (15)	—	Rh2O3 (2)	—
MoO3 (15)	—

Water excluded; ∗An: actinide. ^$Contains additional stainless steel corrosion products, RE: rare earth.
Group half-lives^& are very approximate as they range from short to long times for different components. Absence of half-life value: stable elements.