Thermal runaway of nitric acid-soaked kitty litter in transuranic waste

Michael L. Hobbs, Phillip F. Britt, David T. Hobbs, Michael J. Kaneshige, Michael Minette, Jessica Mintz, Frank M. Pennebaker, Gary R. Parker, Robert Pierce, David M. Rosenberg, Jon Schwantes, Audrey Williams

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Precise wording is important in every field of study, including operational procedures. Confusion in the wording “organic” and “inorganic” may have contributed to substitution of an organic kitty litter for an inorganic adsorbent used to prepare nuclear waste for disposal at an underground salt repository. Adsorbents prevent liquids like nitric acid from causing corrosion within the waste drums. However, combination of organic material with nitric acid can cause heat- and gas-generating reactions resulting in thermal runaway, rapid pressurization, and drum rupture. In 2014, waste Drum 68660 containing nitric acid-soaked organic kitty litter exploded and released transuranic waste into the repository. The cause of the accident was never identified. Here we show that the root cause of Drum 68660 igniting was restriction of the drum vent resulting in accelerated nitric acid chemistry, thermal runaway, and radiation dispersal.

Original languageEnglish (US)
Pages (from-to)543-549
Number of pages7
JournalProcess Safety and Environmental Protection
StatePublished - Nov 2022

All Science Journal Classification (ASJC) codes

  • Environmental Engineering
  • Environmental Chemistry
  • General Chemical Engineering
  • Safety, Risk, Reliability and Quality


Dive into the research topics of 'Thermal runaway of nitric acid-soaked kitty litter in transuranic waste'. Together they form a unique fingerprint.

Cite this