Project History: Construction of SNS

Construction of SNS began with a groundbreaking ceremony in December 1999 and was officially completed in May 2006. During this immense 6.5-year undertaking, as many as 600-800 construction workers were often on the 80-acre site. Many hundreds more people were involved in the design and installation of this one-of-a-kind facility. Because a facility exactly like SNS had never been built, and because the terrain of the site posed its own unique challenges, some novel approaches were taken with many of the construction tasks.

Below you'll find a few of the interesting facts about construction of the facility, some of which might help convey the mammoth size of the project. Construction videos are available that show time-lapsed glimpses at some of the construction and equipment installation tasks.

SNS Construction: Interesting Facts

After tree clearing, 1.4 million cubic yards of earth were moved to prepare for construction.

Project structures called for ~80,000 cubic yards of concrete, equivalent to a sidewalk three feet wide from Knoxville to Nashville, Tennessee (180 miles, 290 km), or the amount of concrete needed to build a typical nuclear power plant.

The Target Building deep foundation contains 937 concrete pilings, reinforced with steel pipe. These pilings range from 35 to 181 feet deep and are seated 10 feet deep into bedrock. Approximately 20 miles of pilings are in place under the Target Building.

Five tests were conducted on the steel/concrete pilings for the Target Building foundation. Both tension and compression were tested to 800,000 lb.

The Target Building weighs as much as a 40-story building of the same footprint.

5,500 tons of rebar were used for project structures.

The SNS electrical substation capacity is 70 MW, or enough electrical capacity to supply electrical service to about 35,000 homes.

Alignment of the tunnel and accelerator components is so critical that the curvature of the earth had to be factored into construction.

Some of the Cost Savings During Construction

Tree and road clearing produced $300K of harvestable timber, which was sold.

Underground utilities were installed during mass excavation to avoid reexcavation later.

Surplus dirt was piled up at the second target building location to compact the foundation for this facility, possibly reducing future construction costs.

Excavating the linac and ring tunnels with scrapers instead of back hoes and dump trucks saved ~$500K.

Using a slip form for concrete pouring and shaping of the linac tunnel saved time, resulting in significant cost savings.

Using Styrofoam molds to form penetrations in the concrete walls of the linac tunnel was another cost saver. These penetrations are for the transverse klystron tube sections.

To find out more about the construction of SNS, contact, Jim Lawson.