( It ( ( ( is therefore ) ( present ( ( ( in ( radioactive waste ) ) and ) ( in ( ( the ( nuclear fallout ) ) ( of ( fission ( bomb explosions ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (ADVP (RB therefore)) (ADJP (JJ present) (PP (PP (IN in) (NP (JJ radioactive) (NN waste))) (CC and) (PP (IN in) (NP (NP (DT the) (JJ nuclear) (NN fallout)) (PP (IN of) (NP (JJ fission) (NN bomb) (NNS explosions)))))))) (. .)))
It is therefore present in radioactive waste and in the nuclear fallout of fission bomb explosions.
(ROOT (S (NP (NNP Fission)) (VP (VBZ is) (NP (NP (NP (DT the) (JJ radioactive) (NN process)) (VP (VBN used) (PP (IN in) (NP (JJ nuclear) (NN power) (NNS plants))))) (CC and) (NP (NP (CD one) (NN type)) (PP (IN of) (NP (JJ nuclear) (NN bomb)))))) (. .)))
Fission is the radioactive process used in nuclear power plants and one type of nuclear bomb.