Question: when did we first start using nuclear energy
[{'answer': 'December 2 , 1942', 'provenance': [{'wikipedia_id': '22153', 'title': 'Nuclear power', 'start_paragraph_id': 28, 'start_character': 259, 'end_paragraph_id': 28, 'end_character': 276, 'bleu_score': 1.0, 'section': 'Section::::History.:First nuclear reactor.\n'}]}]