In the late 1950s, the National Academy of Sciences made a recommendation that highly radioactive waste be disposed of in geologic formations, such as deep salt beds. In the 1960s various areas were explored, and an area near Carlsbad, New Mexico was tested in the 1970s. Congress authorized construction of the Waste Isolation Pilot Project (WIPP) for this site in 1979 and construction began in the 1980s.¹

In the twenty years since WIPP was authorized, the Department of Energy (DOE) has been trying to open the facility for disposal of some of the transuranic (TRU) waste from its sites. But WIPP faces a number of serious criticisms about its technical suitability as a repository.² After years of delay, it has recently been licensed by the Environmental Protection Agency (EPA) to receive transuranic waste. However, it has not yet received a license to receive waste known as "mixed waste," which is a mixture of transuranic waste and chemicals regulated under the Resource Conservation and Recovery Act (RCRA), the US hazardous waste law.³ The vast majority of waste to be placed in WIPP is considered mixed TRU waste.

In an effort to officially open WIPP, the DOE decided to place 36 drums of waste it considered to be non-mixed TRU waste into the repository.⁴ The waste was debris waste, such as used gloves and glovebox parts, rags, plastics, and paper containing plutonium-238 from manufacture at Los Alamos National Laboratory (LANL) of radioisotope thermal electricity generators (RTGs) for the space program. DOE claimed this waste was not hazardous based upon its knowledge of the process used in manufacturing the RTGs. However, IEER's review of DOE's "Acceptable Knowledge" report and its supporting documents found that DOE failed to show sufficient knowledge of waste in the drums to claim it was non-hazardous.

In addition to a number of lapses in the documentation of the waste, which called into question DOE's knowledge of the waste material, there was a serious gap in DOE's technical assessment of the waste. IEER's analysis showed that LANL had failed to properly take into account the chemical changes undergone by certain materials when they are irradiated. This phenomenon, known as radiolysis or radiolytic decomposition, occurs when materials such as plastics and rubber are irradiated, and results in the formation of a number of new chemical compounds. It also causes the enhanced release of chemicals already present in the waste material (see Dear Arjun).

The presence of some of these chemicals in high enough concentrations could cause the waste to meet one or more of the four characteristics of hazardous waste as defined by RCRA (toxicity, corrosivity, ignitability, and reactivity). For example, the presence of hydrogen chloride can cause the waste to be considered corrosive. So while the waste may not have been hazardous when it was initially created, it may have become hazardous due to irradiation while being stored. IEER concluded that some of the waste from LANL's Pu-238 processing most likely met the RCRA hazardous waste definition, which WIPP is not yet licensed to store.

After reviewing the materials submitted by DOE (and those prepared by IEER), the New Mexico Environment Department (NMED), which has jurisdiction over determining compliance with RCRA, decided to require LANL to sample the waste being proposed for emplacement in WIPP order to confirm that it should be classified non-hazardous. While NMED has approved LANL's Confirmatory Sampling and Analysis Plan and the results of the analysis, IEER believes the sampling was insufficient to determine whether or not the waste is actually hazardous. Among other problems, DOE did not conduct the necessary tests to determine whether the concentrations of benzene, acetone, vinyl chloride or hydrogen chloride, four compounds IEER identified as being of potential concern, would be above the levels which would render the waste hazardous under RCRA. Given the highly varied nature of the waste, the difficulty in getting representative samples, and the strong probability that some of the waste meets RCRA's hazardous waste criteria, a more prudent approach would be to assume all the drums in question are hazardous.

This issue extends well beyond the original 36 drums of debris waste. Even with a RCRA permit, WIPP will not be able to accept waste which is corrosive, ignitable, or reactive because the WIPP Waste Acceptance Criteria exclude these categories of waste. It is unknown at this time how much TRU waste is ineligible for WIPP because it has become corrosive, ignitable, or reactive during storage. This further calls into question WIPP's suitability as a repository for mixed transuranic waste. And even if these issues are resolved and WIPP opens, it will not address the vast quantities of buried TRU waste and TRU soil in the complex, which pose far greater environmental dangers than does retrievably stored TRU waste. The first priority should be reducing the risks from buried TRU waste and TRU-contaminated soil.

DOE's rush to open WIPP holds many parallels to its repository program for high-level waste at Yucca Mountain. Both programs are technically unsound and should be abandoned. It is far better to admit now that these programs are fundamentally flawed than to put wastes into them in a rushed manner that is driven mainly by political timetables.