CREATE TABLE table_15564 ("Unit" TEXT, "Type" TEXT, "Net Power" TEXT, "Total Power" TEXT, "Finish construction" TEXT)

What was the net power, when the type was wwer-440/230, and when construction was finished on 24.10.1977?
SELECT "Net Power" FROM table_15564 WHERE "Type" = 'wwer-440/230' AND "Finish construction" = '24.10.1977'
SELECT "Net Power" FROM "table_15564" WHERE "Finish construction" = '24.10.1977' AND "Type" = 'wwer-440/230'