( ( Long-lived isotopes ) ( ( will ( have ( ample ( time ( to ( ( ( spread ( across ( the Earth ) ) ) and ) ( concentrate ( in ( ( food chains ) ( for ( thousands ( of years ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Long-lived) (NNS isotopes)) (VP (MD will) (VP (VB have) (NP (JJ ample) (NN time) (S (VP (TO to) (VP (VP (VB spread) (PP (IN across) (NP (DT the) (NN Earth)))) (CC and) (VP (VB concentrate) (PP (IN in) (NP (NP (NN food) (NNS chains)) (PP (IN for) (NP (NP (NNS thousands)) (PP (IN of) (NP (NNS years)))))))))))))) (. .)))
Long-lived isotopes will have ample time to spread across the Earth and concentrate in food chains for thousands of years.
(ROOT (S (NP (DT The) (JJ long-lived) (NNS isotopes)) (VP (VBP require) (NP (NP (NNS thousands)) (PP (IN of) (NP (NP (NNS years)) (PP (TO to) (NP (NN decay)))))) (PP (TO to) (NP (NP (DT a) (JJ safe) (NN level)) (PP (IN in) (NP (DT a) (JJ nuclear) (NN reactor)))))) (. .)))