Why is 18R closed at DFW?

FlightAware Feature Requests and Ideas
1

and how how long?

2

The NOTAM below as found at the FAA NOTAM site:

08/416 (A4143/12) - RWY 18R/36L CLSD. WIE UNTIL 22 SEP 22:00 2012. CREATED: 28 AUG 23:13 2012