Please try this
SELECT A.KEY_ACCT, A.NUM_ACCT_TYPE, A.CDE_MSDW_SEC
FROM DBQPEDB.TPOS_INTRA A with (NOLOCK) where A.CDE_MSDW_SEC in
(
SELECT B.CDE_MSDW_SEC FROM DBQPEDB.TPOS_INTRA B with (NOLOCK) where B.NUM_ACCT_TYPE = '1'
) and A.NUM_ACCT_TYPE = '0'