Radiochemistry and Nuclear Science

In 1992, the United States discontinued underground nuclear tests. These tests had been used to validate weapons designs, provide experimental data in energy regimes produced in large-scale nuclear excursions, and verify performance of active stockpile weapons. Instead of real-time prompt diagnostics, Los Alamos began to rely on simulation and modeling via advanced computer codes as the principal tool to verify the performance of nuclear weapons.

Today, the historic pedigree of the Laboratory’s radiochemistry data provides a robust benchmark for simulation and modeling. Annual Certification and Lifetime-Extension Programs identify, quantify, and validate specific performance metrics for the current stockpile.

The Laboratory’s special nuclear materials bulk characterization capability integrates with technical nuclear-forensics-related programs and assets, which include the Department of Energy’s Surplus Plutonium Disposition program.

Los Alamos also has the capability to receive, analyze, and process large quantities of special nuclear materials at our plutonium facility and the ability to perform other types for radiological analysis at several different facilities.

• Established the Civilian Nuclear Programs Office to manage projects by the Department of Energy’s offices of Nuclear Energy, Environmental Management, and Nuclear Regulatory Commission. Meeting the civilian nuclear national security demands of the future and maintaining our economy while minimizing the climatic impacts of greenhouse gases will demand that the nation rebuild its civilian nuclear capabilities. Los Alamos is committed to using its advanced nuclear expertise and unique facilities to do just that.
• Established in 2000 a program office Carlsbad to provide scientific support and guidance for WIPP (Waste Isolation Pilot Plant) field operations. The Carlsbad team, which consists of 50 scientists and engineers from the Laboratory’s Earth and Environmental Sciences Division, has expertise in actinide chemistry and repository science and extensive experience in managing and characterizing nuclear waste. It uses this expertise to support the Central Characterization Project, which determines the contents of the waste drums prior to storage. (The transuranic, or “TRU,” waste stored at WIPP was generated during the research and production of nuclear weapons. Many of the waste drums are old and their contents were not properly recorded, so high-tech characterization techniques are needed to determine the contents).
• The Los Alamos team also helps manage the National TRU Program, which works to coordinate the varied disposal activities across the many DOE sites that must ship waste to WIPP.
• Developed TRAC (Transient Reactor Analysis Code) for the Nuclear Regulatory Commission. In 1979, TRAC was used during the Three-Mile Island accident to analyze what happened and to determine how much the reactor core was damaged. Over the years TRAC has been used to analyze and design a variety of test facilities and to analyze a variety of reactor postulated accidents for the Nuclear Regulatory Commission. TRAC is used today by the Nuclear Regulatory Commission and many other organizations around the world.
• Performing chemical-sciences data analysis and modeling for nuclear forensics. Modeling teams use radiochemistry fingerprints and prompt-signal data to reverse engineer exact weapons design while data crunching yields fingerprints of initial fuel and weapon type. Los Alamos originally implemented nuclear forensics in 1945, when Manhattan Project pioneers analyzed debus from the first nuclear explosion. Today nuclear forensics is a mature science, based on the analysis of debris from over a thousand U.S. nuclear tests; extensive research and design in all aspects of nuclear weaponry; modeling of nuclear performance with some of the fastest supercomputers in the world; and use of unique radiological and nuclear facilities at Los Alamos, such as Technical-Area 48, the Chemistry and Metallurgy Research building, and the Plutonium Facility.
• Validating the performance of Laboratory-designed nuclear weapons as measured by radiochemical detectors. We also contribute to future test readiness. As part of this work, we used the DANCE detector, a 160-element BaF2 γ-array, to measure neutron capture and fission cross-sections.
• Applying and developing separation and purification methods covering the entire periodic table to deliver pure analytical samples for radiometric detection and assay. Routine analytes include short- and long-lived fission and activation products, as well as the actinides.
• Using a variety of methodologies and facilities to measure very low concentrations of radionuclides in environmental samples.
• Using radiochemistry, mass spectrometry, and counting technologies to perform routine environmental monitoring. This work supports treaty verification and other threat-reduction missions at Los Alamos.
• Trapping radioactive atoms for a variety of research purposes, including quantum computation.

• Technical Area 48: This technical area at Los Alamos includes the following: 10,000 clean rooms, 10 mass spectrometers, alpha-emitter-handling glovebox facilities, HEPA-filtered fume hoods, inert atmosphere gloveboxes, isotope separators, radiochemistry laboratories, extensive analytical instrumentation, and extensive radioactive decay measurement facilities.
• Radiochemistry User Facility: At this facility, scientists conduct R&D programs in nonproliferation and counter-proliferation, a well as environmental remediation and defense-waste treatment. Users can perform ultrasensitive measurement of actinides, all the while in close physical proximity to laboratories capable of handling multigram quantities of uranium and plutonium.
• Radionuclide Assay Facility: Commonly known as the Countroom, this facility is used to perform qualitative and quantitative assay of gamma-, beta-, and alpha-emitting radionuclides in a variety of matrices and over a range of activity levels. The Countroom focuses on high-precision fission product measurements and alpha spectrometry. The Countroom was founded in support of the U.S. Nuclear Testing Program and has a proud heritage dating back nearly 60 years.
• Chemistry and Metallurgy Research Replacement (CMRR) Facility: The CMRR project includes design, construction, and startup of modern laboratory facilities and office space—and relocation of mission-critical technical capabilities, such as analytical chemistry, materials characterization, and actinide research and development, from the existing Chemistry and Metallurgy Research facility to the new CMRR. The CMRR project will enable the Laboratory to continue its mission to maintain and certify the US nuclear stockpile.

• Todd Bredeweg: Nuclear chemistry
• Ann Schake: Radiochemistry
• Don Dry: Countroom
• Bill Inkret: Assessment
• Rob Steiner: Clean chemistry

• National Nuclear Security Administration
• Department of Defense
• Department of Homeland Security
• Department of Energy Office of Science

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