When did the construction of the unit Chinon B1 with net power of 905 MW start?
CREATE TABLE table_17899 (
    "Unit" text,
    "Type" text,
    "Net power" text,
    "Total power" text,
    "Construction start" text,
    "Construction finish" text,
    "Commercial operation" text,
    "Shut down" text
)
SELECT "Construction start" FROM table_17899 WHERE "Net power" = '905 MW' AND "Unit" = 'Chinon B1'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: When did the construction of the unit Chinon B1 with net power of 905 MW start? ### Input: CREATE TABLE table_17899 (
    "Unit" text,
    "Type" text,
    "Net power" text,
    "Total power" text,
    "Construction start" text,
    "Construction finish" text,
    "Commercial operation" text,
    "Shut down" text
) ### Response: SELECT "Construction start" FROM table_17899 WHERE "Net power" = '905 MW' AND "Unit" = 'Chinon B1'