SuperHENC, the Super High Efficiency Neutron Coincidence counter, will eventually allow Rocky Flats dismantlement workers to begin loading Standard Waste Boxes without segregating different materials. Use of SuperHENC not only will reduce the potential for worker radiation exposure, but the device may help speed up the dismantlement schedule and save an estimated $100 million in the cost of the Rocky Flats remediation.
SuperHENC is a trailer-mounted passive neutron counter that can measure the trace amounts of plutonium present in mixtures of metals, combustibles, and debris packed in SWBs. The instrument provides accurate measurements of transuranic waste and certification of waste for disposal at the Waste Isolation Pilot Plant in Carlsbad, N.M.
The system includes a SWB handling capability and weight indicator device or load cell that can handle and measure loads up to 5,000 pounds, and yet is more accurate than the current WIPP Quality Assurance Objectives for smaller packages.
SuperHENC works by counting the neutrons produced by the spontaneous fission of the plutonium isotopes. The neutron counting process, called coincidence counting, uses special electronic circuitry to distinguish between the neutrons emitted two or three at a time by the fission process, and the typically single, random neutrons emitted by alpha particle reactions. By analyzing the number of double or triple neutrons recorded by a counter within a specified period – usually around 128 micro seconds – workers can determine the plutonium content of the material in the SWBs.
Currently, three commercial vendors have begun the licensing procedure to manufacture more SuperHENC devices. Because of the quality of the current system, none are likely to make any modifications to the Los Alamos design.
SuperHENC is part of a family of sophisticated detectors designed by Los Alamos scientists to aid in the management and control of nuclear materials and wastes.
SuperHENC is the result of a collaboration among members of the Laboratory's Safeguards Science and Technology Group, the Advanced Nuclear Technology group, the Environmental Science and Technology Program and the Rocky Flats Environmental Technology Site. Funding was provided by the DOE through the Rocky Flats Environmental Technology Site. Additional funding came through an Accelerated Site Technology Deployment project from the DOE's Office of Science.
Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, The Babcock & Wilcox Company, and Washington Group International for the Department of Energy's National Nuclear Security Administration.
Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.