NOvA Far Detector building achieves beneficial occupancy

The underground portion of the Far Detector building, which will house the detector, is 67 x 70 x 350 feet. The portion of the building that is above ground is 67 x 40 x 192 feet. Photo: Steve Conley, Burns and McDonnell Engineering

This month, contractors put the final touches on the NOvA Far Detector building in Ash River, Minn. Contractors handed the keys over to the University of Minnesota and the NOvA project on April 13, marking beneficial occupancy.

“Prior to beneficial occupancy, the entire building was under the control of the contractor,” said Steve Dixon, project engineer for NOvA. “Now we can go in and start putting in the infrastructure that’s required to build the experiment.”

Construction, which began on May 1, 2009, included a 3.5-mile all-weather road, and electric, telephone and data communication to the nearly isolated site, costing about $32 million. Funding was provided by the American Recovery and Reinvestment Act.

The University of Minnesota, which is the owner of the NOvA facility, had the building constructed as part of a collaborative research agreement with the DOE at the direction of the NOvA project, said John Cooper, NOvA project manager.

More than 15 firms were involved in the construction of the Far Detector building. Dixon estimates that 20 to 100 people were working on the site at any given time.

The underground portion of the building that will house the detector is 67 feet wide, 70 feet high and 350 feet long.

The location for the Far Detector site was chosen because it is slightly off the path of the currently operating NuMI beam line that goes to the Soudan Mine about 50 miles southeast of Ash River, Minn.

“The location allows us to reuse an existing beam line, which is much cheaper,” said Rick Tesarek, deputy project manager for NOvA.

The next steps for the site include some minor outfitting tasks, painting, exterior work and moving in the block pivoter, a machine that will allow detector components to be assembled and positioned in the detector hall.

Dixon said they hope to achieve final acceptance, the next milestone, in June. Cooper anticipates the collaboration will complete detector installation by the end of 2013 or early 2014.

Christine Herman

A size comparison of the NOvA Far Detector with several well-known landmarks. The detector is 52 x 52 x 220 feet. Graphic: Holabird and Root