Pantex Home to World’s Only Computed Tomography Imaging System for Pit Surveillance
Dana Landrum, Quality Assurance technician, is reflected in the four-sided pyramidal mirror of CoLOSSIS, a computed tomography imaging system unique to Pantex and used to nondestructively determine the integrity of pits.
What does it take to look inside the core of a nuclear weapon? Start with four cryogenically cooled astronomy cameras capable of 8,000 by 8,000-pixel images, one four-sided pyramidal mirror and a burst of photons generated by an X-ray source nearly 100 times more powerful than a medical computed tomography (CAT) scan, and you have the world’s only computed tomography imaging system used to determine integrity of pits – CoLOSSIS.
As many as 1,800 images of each pit are taken over multiple days at Pantex using the Confined Large Optical Scintillator Screen and Imaging System, or CoLOSSIS, to nondestructively determine if they will function as expected. A pit is a component made of plutonium metal and is the heart of a nuclear weapon. The imaging is conducted on surveillance units as designated by the National Laboratories.
Prior to the introduction of CoLOSSIS three years ago, film was used for analysis of pits, which offers only a two-dimensional perspective. But confidence in the nation’s nuclear stockpile required more efficient technology.
The 32,000-pound, lead-shielded CoLOSSIS is operated by highly trained quality assurance technicians whose background stems from the medical or industrial non-destructive evaluation fields.
It takes an average of 15 to 18 hours for CoLOSSIS to work its magic, during which time a component rotates approximately 0.2 degrees for each image until it has rotated 360 degrees to capture an entire data set. During each rotation, the X-ray source known as a linear accelerator, or LINAC, produces photons collected by a scintillator that converts the photons into green light used to create a digital image. Collimators direct the energy, focusing the X-ray beam onto a pyramid-shaped mirror that reflects the light into the cameras, which in turn collect the data.
Data is then transmitted to Lawrence Livermore National Laboratory, designer of the system, and Los Alamos National Laboratory. The labs use computer code to reconstruct the analyses by stitching images taken by the four cameras into one. This offers scientists a three-dimensional view inside the nuclear weapon’s core that they can literally “walk through” to detect manufacturing flaws and the effects of aging.
“This system represents a successful collaboration between Pantex and the Design Laboratories, despite the technical challenges that are to be expected of a one-of-a kind system like CoLOSSIS,” said Gerken.
Designs for a second CoLOSSIS system are in the works and equipment is being procured, Gerken said. “Once operational, this system will give us a second line to aid in workflow throughput and could possibly provide capabilities for analysis of different components,” he said.
Robert Inglis and Forrest McLaughlin (seated) review incoming information at the Operations Center, the 24-hour base often referred to as the Heart of Pantex.
“May I have your attention please?” The room instantly grows quiet as Pantexan listen to the familiar voices for directions, notifications or warnings. The Operations Center (OC) is what some may call the Heart of Pantex. It is responsible for 24-hour management of operations to ensure the overall safety and efficiency of the Pantex Plant.
Established under the Department of Energy’s (DOE) Occurrence Reporting Program in 1990, the OC strives to provide information to the appropriate publics in a timely manner. The Center began operations in a small conference room with few supplies. The need for more equipment and space quickly became obvious. Soon after, operations moved to the building where they remain today.
With 12 years of experience at the Plant, Matt Eberly recently accepted the position as Emergency Services Group manager, which encompasses both Fire and Emergency Management Departments. “The work is extremely important because both the OC and Emergency Services Dispatch Center (ESDC) programs require prompt, safe and reliable action 24/7 to support Plant operations and our surrounding communities,” said Eberly.
“The ESDC and OC teams are required to operate in an environment where precision and effectiveness are critical. They essentially work in the nerve center of all Plant operations.”
The OC consists of nine employees, each with at least 30 years of experience at the Plant. Eight of them are Plant shift superintendents, while Bill Ornelas is Pantex’s Move Right specialist. The OC is responsible for a number of operations, such as weather notification activities, movement of materials and initiation of protective actions for Plant personnel.
Randy Nuttall, who started in the Maintenance Department, enjoys working in the OC because of the diversity within the job. “Every day is different. You never know what the call is going to bring. And it helps that I work with the best group of people,” said Nuttall.
At the Plant's Emergency Dispatch Center, Dorcas Gaddis and Melodi Parton (seated) monitor fire alarms from the Center's testing console.
Across the hall from the OC is the ESDC. Similar to the OC, it houses nine employees working side-by-side. The ESDC is responsible for testing fire alarms throughout the Plant, assisting surrounding counties with emergency calls and for medical and fire emergencies on Plant site.
When the ESDC first started operations in 2006, Don Rhoades, a Pantex veteran, transferred with over 29 years of experience in security. He said the transition was easy and normal, and he enjoys where he is working now. “I love the job itself. Our main goal is to protect life and property, and when I go home at night, I feel a sense of accomplishment knowing that I helped people that day,” said Rhoades.
His colleagues, Dorcas Gaddis and Steve McWilliams both agree that communication is what makes them successful. McWilliams explained that the job comes with great pride in knowing potential lives are saved each day.
Article by Jim Ray, Pantex Wildlife Biologist/Scientist
Good news has come our way once again! Many thanks to our collaborators, who play a major role. They were included in the nomination and are mentioned in the news release.
Here is the link: Pantex Selected for DOE/NNSA's Single Allotted Nomination for an Award.
Photo: West Texas A&M Graduate Student, Robert Dillon, conducting a plot survey for birds in advance of wind energy development. These, and other types of surveys will be repeated following turbine installation for comparison purposes.
Team to represent region at National Science Bowl
After nearly 12 hours of grueling intellectual competition Saturday, a team from Lubbock (Texas) High School edged out the team from Amarillo High School to take top honors at the Pantex High School Science Bowl competition. The Lubbock High team will represent the region at the National Science Bowl in April.
More than 30 teams gathered at West Texas A&M University to test their knowledge of science and math, and to battle it out for a trip to the national competition in Washington D.C.
The Amarillo High team – made up of three sophomores and one freshman – had an excellent competition, moving into the finals without a single loss. The Lubbock High team had to beat another Lubbock team to move into the finals, then beat Amarillo twice for victory in the double elimination competition.
The Lubbock team will be joined at nationals by a team from Panhandle Junior High, which won the middle school competition two weeks ago. Pantex has sponsored the Science Bowl competition in the Amarillo area for 23 years.
Article by Jim Ray, Pantex Wildlife Biologist/Scientist
A lot of data has been gathered on black-tailed prairie dogs and associated species at Pantex. This has involved Pantex Natural Resources staff, Texas Tech University’s Natural Resources Management Department, U. S. Geological Survey’s Texas Cooperative Fish and Wildlife Research Unit at Texas Tech, and the Texas Parks and Wildlife Department. As with the burrowing owl work (previously discussed), resources contributed through those external entities allowed inclusion of study sites from across the Southern High Plains of Texas for some of the objectives.
Upon examining aerial photographs, and following-up with ground-truthing, we found that the slopes above playa wetlands were very important to black-tailed prairie dogs in our region. Plain and simple, these slopes often escape plowing and thus hold remnant patches of prairie for prairie dogs and other wildlife species.
Estimates of black-tailed prairie dogs derived from procedures published by the Rocky Mountain National Arsenal were made in prairie dog colonies by Pantex staff, annually, during 2000-2003. Concurrently, Texas Tech conducted counts, while developing a model that considered date, time, temperature, and the number of prairie dogs observed. While, population estimates were very similar between the original method and the outcome of the new model, the model allows collection of the necessary data in far less time. This reduces the amount of time that busy biologists have to spend in the field conducting counts.
Through the use of grids of live traps we found that abundance of small mammals was similar between grasslands not occupied by prairie dogs, areas where prairie dogs were recently eradicated, and in active prairie dog colonies. However, in looking at individual species, two different graduate students found that the northern grasshopper mouse (Onychomys leucogaster) was more abundant in prairie dog colonies than at sites without prairie dogs. One of the graduate students found that the hispid pocket mouse (Chaetodipus hispidus) and harvest mouse (Reithrodontomys spp.) were more abundant on sites not occupied by prairie dogs.
Among birds, and certainly expected, western burrowing owls (Athene cunicuaria) were most abundant in study plots within active prairie dog colonies. However, the diversity of bird species was similar in areas with and without prairie dogs. One graduate student found that our summer resident bird species were most abundant in active prairie dog colonies, while migrant species were more abundant in plots without prairie dogs. Cassin’s sparrows (Aimophila cassinnii) and lark buntings (Calamospiza melanocorus) were most abundant on active colonies, while abundances of red-winged blackbirds (Agelaius phoenicerus), horned larks (Eremophila alpestris), chipping sparrows (Spizella passerina), and foraging barn swallows (Hirundo rustica) were higher on non-colonized sites.
Our data indicate that ground-dwelling insects were more abundant in active prairie dog colonies than in shortgrass prairie not occupied by prairie dogs. Although the abundance of amphibians did not differ statistically between active colonies and unoccupied grassland, the number captured in active colonies was three times higher than what was found in the absence of prairie dogs.
The collaboration on prairie dogs with Tech has involved several students and resulted in two M.S. theses (McCaffrey 2001, Pruett 2004). To date, four peer-reviewed scientific publications (prairie vole, small mammals/invertebrates, prairie dogs, small mammals) have resulted from the work. Eight presentations on the work have been made at state, national, and international conferences, and even more at meetings characterized as less technical in nature.
Mapping of prairie dog colonies at Pantex is an annual management activity. In fact, mapping of the colonies dates back to at least 1996, making it perhaps the longest-running colony monitoring program for the species in the region.
Photo: This is a herp array, which are used to sample amphibians, reptiles and ground-dwelling insects. These creatures fall into buckets that are buried at the end of each "wing," including the center.