D10 Controller described a loss of separation event when issuing an intercept heading during simultaneous approach procedures in lieu of a go around when the aircraft entered the NTZ.

Narrative

Air Carrier Y; was a DFW arrival from the northeast. Air Carrier Y was vectored at 5;000 FT for the ILS Runway 17L by Arrival Radar 1 (AR1). Five miles northeast of RIVET (TRIP fix) Air Carrier Y was assigned heading 200 to intercept the localizer and was cleared for approach. This placed Air Carrier Y on a course to intercept the localizer 2 miles outside of RIVET. AR1 instructed Air Carrier Y to contact DFW Tower 2.5 miles outside RIVET prior to Air Carrier Y being established on final approach course. Air Carrier Y went through the final prior to the TRIP fix during the turn to join the localizer. Final Monitor 1 (FM1) informed Air Carrier Y that they were right of the localizer and instructed Air Carrier Y to turn 10 degrees left to intercept the final. The Operational Error occurred when Air Carrier Y penetrated the NTZ prior to returning to the Runway 17L localizer. This resulted in a loss of separation with a B737; descending on the ILS Runway 17C. Recommendation; Prior to this; I had to break another guy out because he was about to penetrate the NTZ; I should have broken out Air Carrier Y when he penetrated the NTZ and not given him 10 degrees left to intercept.