LEAD — Scientists plan to build what they consider to be one of the most important physics experiments in the world in Lead if an environmental impact study is favorable to the project. The project could be built on the surface, in Kirk Canyon, or underground at the Sanford Lab, but federal officials want to make sure they understand the environmental effects before proceeding any farther.
Officials from the Fermi National Accelerator Laboratory will be at the Days Inn in Lead from 6:30-8:30 p.m., June 25, and at the Ramkota in Rapid City at 6:30 p.m., on June 26 to host informational meetings as part of an environmental assessment, which will determine the environmental impact that the Long Baseline Neutrino Experiment will have on the area. Representatives from the Long Baseline Neutrino Experiment, Fermilab, the Sanford Underground Research Facility, and the Department of Energy will be on hand to answer questions and provide information about the project. The study is the first step toward building the estimated $50 million neutrino detector, and supporting infrastructure, in Kirk Canyon.
One of the most lauded experiments in high energy physics, the Long Baseline Neutrino Experiment proposes to shoot a beam of neutrinos from Fermilab near Chicago, through the earth to Lead. By doing that, scientists plan to study the properties of neutrinos, especially how the subatomic particles change form in transit. Understanding this phenomena, scientists say, could change the way we understand modern physics.
Recently, Sanford Lab Environmental Manager John Scheetz and Director of Engineering Josh Willhite gave a presentation about the plans to build the LBNE experiment in Kirk Canyon to members of the Lead City Commission. They explained that although scientists’ long-term goal is to locate the experiment 4,850 feet underground in the Sanford Lab, federal budget realities have prompted them to phase the project. With a total price tag coming in at just more than $1 billion, the U.S. Department of Energy has asked the LBNE collaboration to submit a phased approach that will cost no more than $870 million for consideration. LBNE officials are actively seeking outside funds to make up the $125 million to $150 million cost difference to put the experiment underground.
“The DOE said this is the most important thing in physics right now, but we can’t afford it,” Wilhite said.
Though scientists with LBNE are actively seeking those outside funds to build their experiment underground, they are also moving forward with a backup plan that builds neutrino detectors on the surface in Lead. If the LBNE experiment is built on the surface, it will be located halfway between Grizzly Gulch and the Open Cut. Though Wilhite said officials are considering two sites, the most likely location will be near the Oro Hondo substation at Kirk Canyon.
The experiment will consist of two 5 kiloton detectors filled with liquid argon (1.9 million gallons), which will be housed in a 60-foot-deep, 100-foot-long pit. Supporting infrastructure for the detectors will include a 6,500- to 7,500-square-foot building with 10- to 11-foot-thick concrete walls that will shield the detector from outside disturbances, such as cellular phone signals. Additionally, Willhite said the building will be covered with excavated material that will act as an additional layer of shielding.
The liquid argon of the detectors, Wilhite said, will be cooled to a temperature of minus 360 degrees Fahrenheit, and will be circulated to ensure highest purity levels.
Wilhite explained that the noble element Argon, in its highly purified state, will help scientists see the neutrinos, which otherwise pass through the earth undetected.
In order to build the LBNE experiment, Scheetz said officials plan to remove waste rock. If the experiment is built on the surface, there will be about 60,000 yards of waste rock that will be deposited on the site, near the Oro Hondo substation and fan. But before the rock is deposited, officials said it would be tested thoroughly to ensure it does not include any heavy metals or other environmental hazards.
If the experiment is built underground, he said, the lab will generate about 250,000 yards of waste rock, which officials hope to deposit in the open cut. Scheetz said by doing this, water that flows off the rocks will go back into the lab, where officials are pumping water out and through the lab’s treatment plant.
“If you put that waste rock any place else than the Open Cut, it presents a liability to us because it would be more difficult to collect the water that comes off of it to treat it,” Scheetz said. “Water flows into the Open Cut and into our treatment system.”
If lab officials are faced with the prospect of hauling waste rock to the open cut, Scheetz said that could be accomplished in a few ways. One option is to convey the rock from the Ross Shaft and down the hillside to Kirk Road, where it would be loaded on to haul trucks, driven through the city of Lead on Highway 14A and through Central City, and up to the throat of the Open Cut.
Another option, Scheetz said, would be to possibly make use of the old Homestake Mine tramway to haul the rock to the Open Cut.
Planning for two scenarios — an underground facility and a surface facility — does not mean there will be two experiments built. Rather, the extra planning allows scientists to get the ball rolling for different scenarios, in order to keep the experiment on schedule. The underground option, Scheetz said, is about $125 million to $150 million more expensive than the surface option. But still, scientists hope to never have to build the surface facility.
“There is a good possibility that the surface detector will never be built,” Scheetz said, adding that scientists are actively seeking funds to build the underground facility, where they say the best science can be done. “The surface (facility) gets the beam pointed at Lead and gets the detector here so we can study oscillations over distance. It doesn’t allow us to study proton decay and supernovae.”
Willhite reported that Fermilab in Chicago is pointing its neutrino beamline at the Sanford Lab’s 4,850-foot level, rather than at the Kirk Canyon site, in preparation for an underground detector. But it doesn’t matter where they aim the beam, he said, because once it reaches Lead, the stream of neutrinos will be 40 kilometers in diameter.
But before any kind of construction can take place, Scheetz explained that under the National Environmental Policy Act (NEPA), the federal government must conduct an environmental analysis to determine how or whether the project will affect the community, the people and the surrounding environment. Since it is possible that a surface detector could be built along with a future underground detector, officials are focusing their study on both scenarios. Categories to be considered include land use, traffic, recreation, public health and safety, visual impact, noise, socioeconomic impact, and environmental impacts. Consultants are conducting those studies this summer. Representatives of the U.S. Department of Energy are conducting these studies this summer, Scheetz said. The area being studied includes 25 acres surrounding the proposed site along Kirk Road, as well as the former Homestake pipe conveyor route.