Los Alamos Cleanup At the Crossroads:
Treat All Los Alamos Lab Radioactive Wastes Consistently
The Defense Nuclear Facilities Safety Board’s role and responsibility includes gathering information regarding the hazards to the public and workers posed by the management of transuranic (TRU) wastes at Los Alamos National Laboratory (LANL), as well as the Department of Energy’s (DOE) plans to address those hazards. The Board will examine DOE’s actions taken or inadequacies addressed in the current safety policies of the various facilities that manage or store TRU wastes at LANL. The Board is also interested in understanding actions taken to improve TRU waste management at LANL after the improper handling and treatment of TRU wastes that resulted in a ruptured barrel that shut down the Waste Isolation Pilot Plant (WIPP).
The Problem
Transuranic elements have atomic numbers greater than that of uranium, which is 92. Elements within TRU are typically man-made, such as several isotopes of plutonium and americium-241. Because of the elements’ longer half-lives, TRU is disposed of more cautiously than low level radioactive waste. At LANL it is a byproduct of weapons production and nuclear research. TRU is defined by the WIPP Land Withdrawal Act as “waste containing more than 100 nanocuries of alpha-emitting transuranic isotopes per gram of waste with half-lives greater than 20 years…”
Most TRU wastes contain plutonium, which is a radioactive element. Plutonium is usually measured in terms of its radioactivity (curies or becquerels). Both the curie (Ci) and the becquerel (Bq) indicate how much a radioactive material decays every second. The half-life of plutonium-239 is 24,100 years. Plutonium-239 and plutonium-238 are alpha particle emitters. Plutonium-239 and plutonium-240 are produced in nuclear power plants when uranium-238 captures neutrons. Plutonium is used to produce plutonium pits, which are the primary triggers of nuclear weapons.
If plutonium is inhaled, some of it may get trapped in the lungs. Some of the trapped plutonium may move to other parts of the body, mainly bones and liver. The amount of plutonium that stays in the lungs depends on the solubility of the plutonium that is in the air. If plutonium were inhaled today, much of the plutonium would still be in the body 30 to 50 years later. The types of cancers most likely to develop are cancers of the lung, bones, and liver.
TRU Waste Removal at Los Alamos
The Board has expressed concern with the 57 possibly dangerous drums, similar to the one that shut down WIPP, that are awaiting re-packaging at LANL. These 57 drums now stored aboveground in Area G equal 13.8 cubic meters (m3) of TRU and are part of the last of the 3706 Campaign. In January 2012, DOE/LANL and the New Mexico Environment Department (NMED) announced the Framework Agreement, which is a non-binding agreement that outlined commitments to prioritize the disposition of 3,706 cubic meters of TRU waste from LANL to WIPP by June 2014. To date, approximately 383 m3 of the Campaign remain unshipped.
In December 2012, DOE/LANL provided a schedule for disposition of some of the below-ground TRU waste requiring retrieval at Area G. DOE/LANL committed to disposition of six below-ground categories of TRU wastes no later than September 30, 2018. These six categories were identified as (1) Pit 9; (2) Trenches A-D; (3) Corrugated Metal Pipes; (4) Hot Cell Liners; (5) Tritium Packages; and (6) the 17th Remote-Handled Canister. DOE/LANL agreed to meet milestones to disposition 250 m3 by September 30, 2015; 1,000 m3 by September 30, 2016; 1,750 m3 by September 30, 2017; and 2,395 m3 by September 30, 2018. This total of 5,395 m3 remains in the ground awaiting retrieval and disposition.
There is a seventh below-ground category, called the 33 Shafts, for which DOE agreed to complete: (1) a determination as to whether this category contains TRU waste that requires retrieval and removal; and (2) and opportunity for formal public comment under the National Environmental Policy Act regarding retrieval by no later than September 30, 2015. This is yet to be completed.
The 41,000 Cubic Meter TRU Elephant in the Room
Area G opened in 1957. On a volume basis, most of the waste has been placed in unlined pits. Before the mid-1990s, the waste was typically packaged in drums, plastic bags, and cardboard boxes that were then placed into the pits in lifts. Each layer of waste was covered with crushed tuff and compacted using heavy equipment to effectively fill void spaces within the waste and provided an even, consolidated surface for the disposal of more waste. This waste is in addition to the below-ground TRU waste mentioned previously. The pits and shafts at Area G range in depth from 20 to 65 feet.
The LANL- created 2011 Corrective Measures Evaluation (Rev 3) gives estimates on the waste buried at at Area G, for which current plans call to leave in the ground forever –
· Total excavated volume – 1,654,535 yd3 (1,264,982 m3)
· Total waste volume in pits and shafts – 902,815 yd3 (690,251 m3)
· Total TRU – 54,536 yd3 (41,675 m3)
· Total Mixed Low Level Radioactive Waste – 844,388 yd3 (645,580 m3)
Many soil samples collected around the perimeter of Area G contain detectable amounts of americium-241, plutonium-238, and plutonium-239/240. The highest levels were detected in soil samples primarily located on the perimeter of the eastern side of Area G near the Transuranic Waste Inspection Project domes.
LANL recommends only constructing an evapotranspiration (ET) cover over the pits and shafts to provide a barrier to waste and contaminated soils. The ET cover would provide a medium to hold infiltrated water until it is removed by evaporation from the surface and transpiration through vegetation. The alternative also includes constructing and operating a soil-vapor extraction (SVE) system to remove volatile organic compounds (VOCs) in an attempt to prevent the downward migration of these VOCs to the groundwater.
Area G is located above the “sole source” (a legal term designating that extra protection is merited) regional aquifer that provides drinking water for Espanola, Santa Fe, and Los Alamos. The waste site sits in an active seismic zone between the Rio Grande Rift and the dormant Jemez supervolcano.
The Amazing Disappearing Trick
Federal regulations require that disposal systems for spent nuclear fuel or high-level or transuranic radioactive wastes are designed to provide a reasonable expectation, based upon performance assessments, that the cumulative releases of radionuclides to the accessible environment for 10,000 years after disposal from all significant processes and events that may affect the disposal system shall not exceed certain levels. (40 CFR §191.13 Containment Requirements)
However, most of the estimated TRU waste in Area G was disposed of before 1970. DOE guidance states that TRU regulations do not apply to disposal that occurred prior to promulgation of the regulations. The 1985 version of the regulations states that the standards do not apply to waste disposed prior to the effective date of the rule. This excludes from the regulations waste that is colloquially known as “pre-1970 TRU waste”, “suspect buried transuranic waste”, and possibly by other names, if the waste is left in place. If the waste is exhumed, the waste becomes subject to the currently applicable regulations. (DOE G 435.1 Chapter III – Transuranic Waste Requirements)
With little public notice, DOE officially approved Area G as a Low Level Radioactive Waste (LLW) disposal facility in 2010, after 100’s of thousands of cubic meters of LLW had already been disposed. But to dispose of LLW at Area G, DOE Order 435.1 required the Laboratory to have an approved performance assessment (PA)/composite analysis (CA). DOE claimed that the Area G PA demonstrated that a reasonable expectation existed that the potential releases from the facility will not exceed performance objectives established in DOE Order 435.1 during a 1000-yr period after closure. The Area G CA only accounted for all other sources of radioactive material that were planned to remain on-site at the Laboratory that may interact with the LLW disposal facility and contribute to the dose projected to a member of the public from Area G. (LANL Environmental Report 2013 2-11) The TRU in Area G was assessed in the composite analysis only to investigate its effects on the LLW, and was not assessed as waste in its own right.
Request for 10,000-year Assessment for Area G
The TRU waste (limited up to a total of 176,000 m3) buried 2100 feet underground in WIPP has a Performance Assessment of 10,000 years. The estimated 41,675 m3 of TRU buried 65 feet, or less, underground in Area G at LANL has a Performance Assessment of 1,000 years.
If DOE’s remediation goals are to genuinely protect public health and the environment from long-term risks, then DOE must excavate the TRU wastes in Area G for disposal at WIPP. In any event, DOE should perform a 10,000-year (not 1,000) performance assessment on ALL TRU wastes buried at the Los Alamos National Laboratory, including pre-1970 TRU wastes.
