Question: when did the first nuclear power plant open
[{'answer': 'June 27 , 1954', 'provenance': [{'wikipedia_id': '22153', 'title': 'Nuclear power', 'start_paragraph_id': 37, 'start_character': 3, 'end_paragraph_id': 37, 'end_character': 17, 'bleu_score': 1.0, 'section': 'Section::::History.:Early years.\n'}]}, {'provenance': [{'wikipedia_id': '22153', 'title': 'Nuclear power', 'start_paragraph_id': 37, 'start_character': 0, 'end_paragraph_id': 37, 'end_character': 212, 'bleu_score': 0.633926050304301, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6403892477198557493}, 'section': 'Section::::History.:Early years.\n'}]}]