Legacy Waste Program nearing completion
NNSA Sandia Site Office Manager Patty Wagner says the shipments mark a significant milestone on the journey to remove nuclear materials from Sandia.
“NNSA has worked closely with Sandia since the decision was made in 2004 to reduce the nuclear footprint at this site,” says Wagner, “and I am very pleased that, despite several obstacles, Sandia has successfully met its commitments and accomplished the effort without incident.”
The waste being removed is the byproduct of nuclear defense program research and weapons production. Much of the waste removed from Sandia came from programs completed in the 1980s.
Depending on the level of radioactivity, the waste was packaged for disposition in lower-level contact-handled waste containers (CH-TRU) or higher-level remote-handled waste containers (RH-TRU).
Both the RH-TRU and CH-TRU disposed of at WIPP consist of tools, rags, protective clothing, and other materials contaminated with radioactive elements that have atomic numbers greater than uranium (transuranic).
RH-TRU waste produces a higher dose rate than CH-TRU waste at the surface of the disposal container, but when transported RH- and CH-TRU waste have the same dose rate limit on the outside of the shipping casks due to lead shielding.
Before any of the waste left for WIPP, the Environmental Protection Agency (EPA) and New Mexico Environment Department (NMED) reviewed Sandia’s documentation for determining the physical and chemical characteristics of the waste, to ensure its safe disposal at WIPP.
Remote-handled (RH-TRU) removal
Beginning in the summer of 2011, employees in Non-Reactor Nuclear Facilities Dept. 1387 and WIPP Central Characterization Project (CCP) personnel worked for more than a year in the Tech Area 5 Auxiliary Hot Cell Facility (AHCF) to analyze and repackage the remotely handled RH-TRU waste for shipment. CCP personnel on site were able to certify as safe the RH-TRU waste, so it could be sent directly to the WIPP facility for disposition.
The AHCF, a small, heavily shielded concrete box, was established specifically to process and disposition legacy nuclear material and waste. A crane brings waste materials into the cell through a roof door. Crew members examine the waste material through thick, leaded windows, and use glovebox-style manipulator arms to examine the material and take samples.
During the RH-TRU project, workers confirm that the waste materials have been correctly described and documented, and then repackage the waste, which is then removed through the cell’s roof door.
On Dec 16, 2011, WIPP received the first of eight planned RH-TRU shipments from Sandia. WIPP is designed to safely isolate defense-related TRU waste from people and the environment. Operating since 1999, WIPP receives waste temporarily stored at sites around the country, and permanently disposes of it in rooms mined out of an ancient salt formation 2,150 feet below the surface.
RH-TRU waste will make up only about 4 percent ─ or 7,080 cubic meters ─ of the total volume of waste received at WIPP.
Contact-handled (CH-TRU) removal
Prior to the removal of remote-handled transuranic waste, employees in Radioactive Waste/Nuclear Material Disposition Dept. 4139 removed all of Sandia’s lower-level CH-TRU waste.
Beginning in December 2010, Sandia packaged and sent its CH-TRU waste to Idaho’s Advanced Mixed Waste Treatment Project, where it was certified to ensure that the waste was of a level appropriate for CH-TRU disposal.
The first of three CH-TRU shipments left Sandia in December 2010, with the second one leaving in March 2011, and the final CH-TRU shipment in October 2011. The CH-TRU sent as part of the first two shipments was then certified in Idaho and shipped to WIPP for disposal. Drums from the final shipment were recently certified in Idaho and shipped to WIPP.
CH-TRU waste must emit less than 200 millirem per hour on contact, on the side of the drum. This relatively low level of gamma radiation means that, when properly packaged, the drums can be handled directly by workers in appropriate gear.
Removing legacy wastes a priority
DOE National TRU Program Director J.R. Stroble says the shipment is significant to WIPP.
“Our goal is to reduce the nation’s nuclear waste footprint and we routinely receive shipments from around the country,” says Stroble. “This first shipment of RH-TRU waste from Sandia begins the final stages of eliminating legacy TRU waste from a DOE site in New Mexico.”
Nationally, DOE has prioritized removing legacy waste from small-quantity sites, such as Sandia. Removal of the TRU waste was also a contract incentive (PBI3) for Sandia, so completing the removal met a contractual requirement that was given high priority by NNSA.
For Sandia, proper disposition of legacy waste reduces programmatic and regulatory risk associated with the continued storage of such waste forms. Another benefit is that it demonstrates the opening of a pathway for TRU waste so future projects that may generate similar materials have a viable path out the door.
Additionally, DOE also assured New Mexico legislators that removal of legacy waste in New Mexico would be a priority. In addition to waste removal at Sandia, DOE has overseen the removal of 913 shipments from Los Alamos National Laboratory in northern New Mexico for final disposition to WIPP.
The last four shipments RH-TRU shipments are expected to leave Sandia in March, and will conclude the cleanup of all legacy TRU wastes at Sandia.-- Stephanie Holinka
Sandia researchers, UK partners publish groundbreaking work on Criegee intermediates in Science magazine
In a breakthrough paper published in this week’s issue of Science magazine, researchers from Sandia’s Combustion Research Facility and the University of Manchester and Bristol University report the potentially revolutionary effects of Criegee biradicals.
These chemical intermediates are powerful oxidizers of pollutants produced by combustion such as nitrogen dioxide and sulfur dioxide. Although Criegee intermediates — carbonyl oxides — were hypothesized in the 1950s, it is only recently that they have been detected. Previously, scientists only had indirect knowledge of their reaction kinetics.
“This is a breakthrough discovery, but really only the opening of the door on this work. The results from this study, and the doors this work opens for future studies of Criegee intermediates, will make models of the troposphere more accurate, providing a better understanding of how anthropogenic and biogenic chemistry together shape our planet’s environment,” says David Osborn (8353).
The article, titled Direct Kinetic Measurements of Criegee Intermediate (CH2OO) Formed by Reaction of CH2I with O2, reports the first direct kinetics measurements made of reactions of any Criegee species, in this case formaldehyde oxide (CH2OO). These measurements determine rate coefficients with key species, such as sulfur dioxide (SO2) and nitrogen dioxide (NO2), and provide new insight into the reactivity of these transient molecules.
The detection and measurement of the Criegee intermediate reactions were made possible by a unique apparatus, designed by Sandia researchers, that uses light from a third-generation synchrotron user facility, Lawrence Berkeley National Laboratory’s Advanced Light Source, to investigate chemical reactions that are critical in hydrocarbon oxidation. The intense tunable light from the synchrotron allows researchers to discern the formation and removal of different isomeric species — molecules that contain the same atoms but are arranged in different combinations.
In the Science publication, the researchers reported a new means of producing gas-phase Criegee intermediates and used this method to prepare enough CH2OO to measure its reactions with water, SO2, nitric oxide (NO), and NO2. The ability to reliably produce Criegee intermediates will facilitate studies of their role in ignition and other oxidation systems.
The researchers found that the Criegee biradicals react more rapidly than first thought. Moreover, the British and Manchester investigators demonstrated these kinetics results imply a much greater role of carbonyl oxides in tropospheric sulfate and nitrate chemistry than models had assumed, a conclusion that will substantially impact existing atmospheric chemistry mechanisms.
For example, SO2 oxidation is the source of sulfate species that nucleate atmospheric aerosols. Because the oxidation of SO2 by the Criegee intermediate is much faster than previously assumed, Criegee reactions may be a major tropospheric sulfate source, changing our picture of tropospheric aerosol formation.
This capability breakthrough was funded by the Office of Basic Energy Sciences (BES) in DOE’s Office of Science, and conducted using the Advanced Light Source at Lawrence Berkeley National Laboratory, a scientific user facility supported by BES.-- Vanitha Sankaran
National Nuclear Science Week a glowing success
Each day during National Nuclear Science Week, Jan. 23-27, Albuquerque’s National Museum of Nuclear Science & History slated hands-on activities to introduce 250 middle school and high school students to the breadth of the nuclear world.
The schedule called for everything from atomic modeling and chain reactions to workshops on radiation and basic energy programming, says museum Director Jim Walther. Local chapters of the American Nuclear Society (ANS) and North American Young Generation in Nuclear (NA-YGN) helped museum staff and volunteers with the presentations.
This year’s 3rd annual National Nuclear Science Week continues the theme of “Get to Know Nuclear,” aimed at promoting careers in nuclear and other sciences, technology, engineering, and math. The National Museum of Nuclear Science & History, a Smithsonian affiliate, sponsors the week and is largely responsible for creating it.
The designated week, the fourth week in January, came about because museum staff and corporate partners wanted a way for educational institutions and the industry to be able to talk broadly about nuclear energy, Jim says.
Industry has embraced Nuclear Science Week
“So it became a little bit of our advocacy role,” he says. The museum, chartered by Congress, is one of only a few national museums outside of Washington, D.C. Due to its location, Jim says, “we have to have a national footprint, and this is part of a way to do it.”
The week quickly became a national effort as many partners in the nuclear industry embraced it as filling a need and promoted it, he says.
Each year the celebration centers around a different location, and the location that was host the previous year marks the week with events the next year. In that way, Jim says, the celebration has grown remarkably in its short lifetime.
“It’s kind of viral on a personal level because people get excited about doing something,” he says.
This year the museum’s partners included the National Science Teachers Association and Chicago’s Illinois Institute of Technology, which was hosting four webinars for live broadcast on Nuclear Science Day, Jan. 25, says Jeanette Miller, museum marketing director. Students and teachers nationwide were invited to log on to listen to the webinars and ask questions. Other Nuclear Science Day sponsors are the ANS, the Nuclear Energy Institute (NEI), the Society of Nuclear Medicine (SNM), Exelon Corporation and Entergy.
Teachers and others were invited to download free curriculum and information at www.NuclearScienceWeek.org. The site includes suggested lesson plans and classroom presentations.
“If an eighth-grade classroom is talking about radiation, there’s an activity for them,” Jim says.
Nuclear world is everywhere
Elsewhere, the agenda for the week included presentations at schools and colleges, some channeled through ANS chapters; a briefing for congressional staffers in Washington on nuclear science, nuclear power, and jobs; and events scheduled at such DOE sites as Savannah River in South Carolina, Idaho National Laboratory, and Argonne National Laboratory near Chicago, Ill.
National Nuclear Science Week is meant for the general public, but Jim says the way to reach adults is to reach children.
“That’s how you do it. You hook the family, you hook the kids, you get the moms and dads that way, and you begin the broader conversation about nuclear power or nuclear medicine or whatever,” he says.
The nuclear world is everywhere, from nuclear medicine in local hospitals to nuclear industry manufacturing plants to towns that have nuclear power or, in the case of communities like Albuquerque, that have national laboratories and many people working in the industry.
The museum’s national steering committee set five subject areas before the first celebration in 2010, and this year they broke down this way: Monday, education about all things nuclear; Tuesday, careers; Wednesday, nuclear energy generation; Thursday, nuclear safety; and Friday, nuclear medicine.
Focusing on careers is important in an era of increasing emphasis on creating jobs, Jim and Jeanette say. But Jim says it’s also important to the museum because “we’re interested in preparing young people to be technically capable of being employees someday. We don’t care if they work for the labs or wherever, but we want them to be better prepared for the world they’ll face when they get there.” Jeanette adds: “And scientifically literate and proficient just in order to be better prepared all around.”
Supporters of National Nuclear Science Week wanted to talk about safety because “that ends up being one of the things the adult population cares about when it comes to nuclear: ‘Is it safe? How safe is it?’” Jim says.
Nuclear medicine was a natural topic because it’s a huge part of modern health care. In the United States alone, nuclear medicine is used to diagnose or treat 55,000 people every day, he says.
Many partners promoting events also advocate for nuclear energy to contribute a larger part of the nation’s electricity, so more discussion of those issues is needed, Jim says.
Jeanette says the designated week also provides a platform “for breaking down a little bit of the fear factor that goes with ‘nuclear.’”
“If people don’t have a strong science background, this is a way to sort of say OK, let’s take this step by step. There are ways to learn about nuclear; it doesn’t have to be an overwhelming, scary topic,” she says.
National founding partners included in the recognition week are ANS, the American Society of Radiologic Technologists, Arizona Public Service, Areva, Entergy, Exelon, and LES. National presenting partner organizations, which sponsor activities in their regions, are Sandia, Los Alamos National Laboratory, DOE, NEI, SNM, NA-YGN, and US Women in Nuclear. National corporate sponsors are the Albert I. Pierce Foundation, Energy Solutions Foundation, and Idaho National Laboratory. -- Sue Major Holmes-- Sue Major Holmes