When did the construction of the unit Chinon B1 with net power of 905 MW start?
CREATE TABLE table_12983929_1 (construction_start VARCHAR, net_power VARCHAR, unit VARCHAR)
SELECT construction_start FROM table_12983929_1 WHERE net_power = "905 MW" AND unit = "Chinon B1"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_12983929_1 (construction_start VARCHAR, net_power VARCHAR, unit VARCHAR) Question: When did the construction of the unit Chinon B1 with net power of 905 MW start? [/INST] SELECT construction_start FROM table_12983929_1 WHERE net_power = "905 MW" AND unit = "Chinon B1" </s>