Question: when did the soviet union exploded its first atomic bomb
[{'answer': '29 August 1949', 'provenance': [{'wikipedia_id': '1217440', 'title': 'Soviet atomic bomb project', 'start_paragraph_id': 5, 'start_character': 3, 'end_paragraph_id': 5, 'end_character': 17, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1217440', 'title': 'Soviet atomic bomb project', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 168, 'bleu_score': 0.7506346798217071, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17875417396311320906}, 'section': 'Section::::Abstract.'}]}]