Question: when was nuclear energy first commercially used in the united states
[{'answer': '1958', 'provenance': [{'wikipedia_id': '4131402', 'title': 'Nuclear power in the United States', 'start_paragraph_id': 15, 'start_character': 333, 'end_paragraph_id': 15, 'end_character': 337, 'bleu_score': 1.0, 'section': 'Section::::History.:Start of commercial nuclear power.\n'}]}, {'provenance': [{'wikipedia_id': '4131402', 'title': 'Nuclear power in the United States', 'start_paragraph_id': 15, 'start_character': 0, 'end_paragraph_id': 15, 'end_character': 1038, 'bleu_score': 0.9666950091602231, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15261646940908465875}, 'section': 'Section::::History.:Start of commercial nuclear power.\n'}]}]