Tritium Management at Fermilab Stuart Henderson Associate Laboratory Director for Accelerators...
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Transcript of Tritium Management at Fermilab Stuart Henderson Associate Laboratory Director for Accelerators...
Tritium Management at Fermilab
Stuart HendersonAssociate Laboratory Director for Accelerators
Community Advisory Board MeetingAugust 23, 2012
Outline
• What is Tritium?
• How and where is it produced?
• How are we managing tritium?
• In what forms does tritium leave the site?
• What about the future?
• Summary
Stuart Henderson, Community Advisory Board, August 23, 20122
What is Tritium?• Weakly radioactive isotope of hydrogen with 12.3 year
half life
• It decays into helium by emitting a low-energy electron which does not penetrate the skin
• Behaves chemically like hydrogen, so is found most prominently in water molecules (HTO rather than HHO)
• Does not accumulate in body when ingested.
• Prolonged exposure by drinking tritiated water over many years poses a cancer risk
Stuart Henderson, Community Advisory Board, August 23, 20123
4
How and where is it produced?
• Tritium is created as an expected by-product of our accelerator operations
• When high-energy protons hit other particles or matter, they can produce tritium.
• In March 2005, Fermilab started operating a new proton beam line to create neutrinos for the MINOS experiment. It is the main source of tritium at Fermilab.
Stuart Henderson, Community Advisory Board, August 23, 2012
5
The NuMI/MINOS Tunnel
The tritium is incorporated into the water that is being pumped out of the tunnel and then is transported to the surface.Stuart Henderson, Community Advisory Board, August 23, 2012
How are we managing Tritium?• Our management approach is guided by the following:
Fermilab takes this issue very seriously We’re not satisfied with just meeting regulatory limits We are committed to being both good neighbors and good
stewards We are committed to keeping the amounts of tritium produced
and discharged from the site as low as possible
Stuart Henderson, Community Advisory Board, August 23, 20126
• Since 2005, when low levels of tritium were first detected in Indian Creek, we have put in place many measures to minimize the amount of tritium in ponds and creeks
Tritium Working Group
• The lab’s Tritium Working Group, a group of physicists and engineers, works to
characterize tritium sources in present and future operations
study and recommend mitigation and monitoring approaches
provide overall coordination and guidance on tritium management
S. Henderson, Community Advisory Board, August 23, 20127
In what forms does tritium leave the site?
• In surface water
• In the sanitary sewer system discharge
• In the air by emissions
• In drums, after solidification, for transport to a licensed waste disposal facility
Stuart Henderson, Community Advisory Board, August 23, 20128
Tritium in surface water• First detected very low levels of tritium in Indian Creek
in 2005, for the first time in the 40-year history of the lab’s environmental monitoring program
• Levels are far lower than the standards Fermilab is required to meet and pose no health or environmental risk
• U.S. Department of Energy standard for surface water is less than 1,900 picocuries per milliliter, whereas our readings are in the single digits
• In fact, the concentrations remain below even the US EPA drinking water standard of 20 pCi/ml
Levels are well below DOE standard
Stuart Henderson, Community Advisory Board, August 23, 20129
Indian Creek results posted on the web site
S. Henderson, Community Advisory Board, August 23, 201210
Tritium in the sanitary sewer• We routinely sample our sanitary sewer discharge that is sent to
wastewater treatment facilities in Batavia and Warrenville as part of our surveillance monitoring program
• Samples taken from sewage discharge to Batavia first showed very small, but detectable, levels in 2005.
No tritium has been detected in sanitary sewer discharge sent to Warrenville
• Whereas sanitary sewer tritium concentrations rose and fell in the mid to late 2000s, levels since 2010 remain above detection limits
• The DOE standard for sanitary sewer discharge is larger than that for surface water: 9,500 pCi/ml (limited to 5 Ci/year in total)
• To date, the highest level detected is 7.5 pCi/ml
Tritium concentration in the sanitary sewer discharge is well below DOE standards
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Tritium in sanitary sewer discharge to Batavia
S. Henderson, Community Advisory Board, August 23, 201212
The Tritium Working Group is presently focused on reducing levels in the sanitary sewer water
What about Batavia discharge to the Fox River?
Fermilab generated Tritium in the Fox River is dwarfed by the natural tritium concentrations in rainwater
S. Henderson, Community Advisory Board, August 23, 201213
Tritium emissions to the air• Tritiated water evaporates from ponds, is evaporated in
the cooling towers and another service building evaporation system, and is emitted by ventilation systems
• The EPA sets limits on the amount of radioactive material that can be sent into the air such that the dose to an individual member of the public remains below 10 millirem in a year
• The highest annual dose at a particular location is 0.04 millirem due to airborne emission
Fermilab’s emissions are far below the EPA standard
Stuart Henderson, Community Advisory Board, August 23, 201214
Tritium in disposed solid waste• There are a few water systems at Fermilab that have
tritium concentrations above the surface water DOE standards.
• When it needs to be disposed, that water is contained in 55-gal drums, solidified in place and transported to a licensed waste facility in Utah.
• Fermilab transports about 250 drums of this solid waste to the Utah facility each year, in two shipments.
• Because of tritium’s low radioactivity, it is not considered a hazardous material by the DOT, however we do follow the DOE requirements for disposal.
Stuart Henderson, Community Advisory Board, August 23, 201215
What about the future?• We are constructing the NOvA neutrino experiment and will begin
NOvA operation in 2013. The environmental assessment led to “finding of no significant impact.”
With a doubling of beam power we could expect, without further mitigation, twice the tritium levels. But we are actively exploring additional mitigation.
• We propose to build a new proton/neutrino beam line for the Long-Baseline Neutrino Experiment (LBNE), which would produce tritium
The present concept for LBNE has a target facility on the surface, and other enhancements for much better tritium management
• We hope to build Project X, which would further increase proton intensity and create more tritium
We are working hard to get the tritium issue right so that we retain the confidence of all our stakeholders in our ability to do
future projects16
Summary
• Tritium concentrations are very small, but detectable, in surface waters, sewer water and air emissions
• All measured tritium concentrations are well below applicable DOE and EPA standards
• There is no threat to health or the environment• We are actively managing tritium on the Fermilab
site• We are committed to keeping the amounts of tritium
produced and discharged from the site as low as possible both now and in the future
S. Henderson, Community Advisory Board, August 23, 201217