Staff Reports
NS&D Monitor
2/5/2016
Pit-making operations will resume at the Los Alamos National Laboratory this year, according to the Department of Energy. There are currently no pits being made at Los Alamos, but the job of manufacturing plutonium triggers for nuclear weapons will begin again when operations resume at LANL’s flagship Plutonium Facility, PF-4.
“[O]perations will resume in 2016 to build development pits that support the planned rates established by the Department of Energy in coordination with the Department of Defense,” according to a statement Thursday by the National Nuclear Security Administration’s Los Alamos Field Office. “With developmental pits, the laboratory demonstrates its pit manufacturing capability, proving to the government that LANL can manufacture production pits to go into the stockpile.”
Development pits are produced for the purpose of defining, fine-tuning, and qualifying the manufacturing processes. When the quality reaches the optimum standard, the pits are certified as war reserve pits, which means they have qualified for use in the nuclear stockpile. The Department of Energy’s fiscal 2016 Stockpile Stewardship and Management Plan calls for producing four to five development pits annually after the Plutonium Facility has resumed operations. LANL’s pit development timeline calls for progressive development builds through 2023, when the first war reserve pit is due.
There are many deadlines to meet in the next 15 years. A significant change in the stockpile plan for this year called for additional resources for forging ahead with the pit-making strategy in order to meet another major appointment, which is to evacuate the lab’s aging Chemistry and Metallurgy Research Building in fiscal 2019. The CMR’s analytic chemistry (AC) and material characterization (MC) activities are closely tied to plutonium processing and will have to be relocated.
This will not be easy because a great deal of AC-related space is needed for pit production. AC is used from beginning to end in the manufacturing process. In a 2014 Congressional Research Service report, Jonathan Medalia described the distinct roles of AC and MC:
"AC is performed on an average of 22 samples per pit. Metal samples taken directly from hemishells are typically 5 grams each. In preparing for AC, these samples are cut into smaller pieces. Most of the smaller pieces are dissolved in acid because most AC instruments do not use samples in solid form. The resulting plutonium-acid mixture is split into still smaller samples, many of which contain milligram or microgram quantities of plutonium. Each sample must be prepared in a specific way, and analyzed using specific equipment, depending on the type of analysis that it is to undergo. In addition, before plutonium ingots are used for a hemishell, their purity must be assayed. This involves taking a sample from a piece of the purified product as well as plutonium standard and reference materials for comparison. In order to provide one assay result for the plutonium, the assay process is typically run ten times."
Materials characterization, while also important, plays a more limited role, Medalia noted: “Materials characterization (MC) examines bulk properties of plutonium samples, such as tensile strength, magnetic susceptibility, and surface characteristics.” MC is also useful for troubleshooting and production problem-solving.
The Pentagon has requested that the Department of Energy demonstrate the capacity for making 10 reserve pits a year by 2024, while ramping up to 50 to 80 pits by fiscal 2030, a quantity that is calculated to cover routine operations and meet new and broader safety and security requirements for the U.S. nuclear arsenal. Such an effort would guard against unexpected technical challenges or geopolitical events that might change previous assumptions.
In order to achieve the goal, LANL has been asked to reconfigure remnants of past plans that have never produced more than six to 10 pits annually. The current authorized capacity for the site under the National Environmental Policy Act is 20 pits a year.
To establish sufficient space for the expanding activities, two or three new modular structures would be built underground in proximity to the 60,000-square-foot laboratories at PF-4. The modules would be buried and linked to other buildings underground. These would cost $2 billion to $3 billion, according to informal estimates. They would be used for storage, additional pit-making, and a multitude of plutonium support activities. This subproject, the Plutonium Modular Approach, was approved as a concept at the end of 2015 for mission need Critical Decision (CD)-0, with a completion date projected for 2025 to 2027, according to a Defense Nuclear Facilities Safety Board site report for the week ending Dec. 18, 2015.
LANL and NNSA managers in 2014 began a series of pre-conceptual studies to determine the feasibility of making more use of existing infrastructure, like the Radiation Laboratory Utility Office Building (RLUOB), which was a new building under a previous plan, meant to house only 8.4 grams of pu-239-equivalent at that time. Now, more demands are being made on it.
To meet the anticipated workload and additional radiological requirements RLUOB has been upgraded from a radiological facility handling negligible amounts of radioactive material to a nuclear facility with authorization to operate with a maximum of 38.6 grams of pu-239-equivalent radioactive material. Furthermore, NNSA has been investigating for more than a year whether LANL can increase that limit again to as much as 400 grams pu-239 equivalent by reclassifying the structure as a Hazard Category 3 building.
Like many provisions in the new plan, this has caught the attention of LANL watchdogs. A weekly radio update from Concerned Citizens for Nuclear Safety in Santa Fe reports, “The increase is substantial and NEPA requires the federal nuclear weapons agencies to supplement their environmental impact statement, with opportunity for public review and comment, as well public hearings.”
So far there has been no indication on the issue of how the NEPA process would be applied to the new pit production agenda. Asked about the sharp plutonium authorization increase, the NNSA site office at LANL replied: “The RLUOB continues to operate as a Radiological Facility with a limit of 38.6 grams of Pu-239 equivalent; any changes to RLUOB’s hazard category will be executed consistent with regulatory requirements.” The statement added, “Details on the re-structuring will be available in the FY 2017 President’s Budget Request.”
