( ( As ( ( the ( nuclear reactor ) ) operates ) ) ( , ( ( uranium atoms ) ( ( ( ( fission ( -LRB- ( ( split apart ) -RRB- ) ) ) and ) ( release energy ) ) . ) ) ) )
(ROOT (S (SBAR (IN As) (S (NP (DT the) (JJ nuclear) (NN reactor)) (VP (VBZ operates)))) (, ,) (NP (NN uranium) (NNS atoms)) (VP (VP (VBP fission) (PRN (-LRB- -LRB-) (VP (VBN split) (ADVP (RB apart))) (-RRB- -RRB-))) (CC and) (VP (VBP release) (NP (NN energy)))) (. .)))
As the nuclear reactor operates, uranium atoms fission (split apart) and release energy.
(ROOT (S (NP (JJ Nuclear) (NN energy)) (VP (VBZ is) (VP (VBN released) (SBAR (WHADVP (WRB when)) (S (NP (NP (DT the) (NN nucleus)) (PP (IN of) (NP (DT an) (NN atom)))) (VP (VBZ is) (VP (VBN split))))))) (. .)))