The items related to nuclear fusion reactions are:
A. Requires very high temperatures to start the reaction - True. Fusion requires extremely high temperatures to overcome the repulsive forces between atomic nuclei.
B. Occurs in the sun - True. The sun primarily generates energy through nuclear fusion, converting hydrogen into helium.
C. Involved in chain reaction - False. Chain reactions are characteristic of nuclear fission, not fusion.
D. No radioactive waste is produced - Generally True. Fusion produces less long-lived radioactive waste compared to fission, but some neutron activation can produce some radioactive materials.
E. Used in nuclear power plants - False. Currently, most nuclear power plants use nuclear fission, not fusion, to generate energy.
So the correct answers are A, B, and D.