Evaluating chemical toxicity of surface disposal of LILW-SL in Belgium

D. Mallants, L. Wang, E. Weetjens, Wim Cool

Research outputpeer-review

Abstract

ONDRAF/NIRAS is developing and evaluating a surface disposal concept for low and intermediate level short-lived radioactive waste (LILW-SL) at Dessel, Belgium. In support of ONDRAF/NIRAS's assignment, SCK·CEN carried out long-term performance assessment calculations for the inorganic non-radioactive components that are present in LILW-SL. This paper summarizes the results obtained from calculations that were done for a heavily engineered surface disposal facility at the nuclear zone of Mol/Dessel. The calculations address the migration of chemotoxic elements from the disposed waste to groundwater. Screening calculations were performed first to decide which non-radioactive components could potentially increase concentrations in groundwater to levels above the groundwater standards. On the basis of very conservative calculations, only 6 out of 41 chemical elements could not be classified as having a negligible impact on man and environment. For each of these six elements (B, Be, Cd, Pb, Sb, and Zn), the source term was characterized in terms of its chemical form (i.e., metal, oxide, or salt), and a macroscopic transport model built that would capture the small-scale dissolution processes relevant to element release from a cementitious waste container. Furthermore, reliable transport parameters in support of the convectiondispersion-retardation (CDR) transport calculations were determined. This included derivation of (1) solubility for a cementitious near field environment based on thermodynamic equilibrium calculations with The Geochemist's Workbench, and (2) distribution coefficients based on a compilation of literature values. Scoping calculations illustrated the effects of transport parameter uncertainty on the rates at which inorganic components in LILW-SL leach to groundwater.

Original languageEnglish
Title of host publicationMaterials Research Society Symposium Proceedings - Scientific Basis for Nuclear Waste Management XXXI
Place of PublicationWarrendale, United States
PublisherMRS - Materials Research Society
Chapter689
Pages689-701
Number of pages13
Volume1107
ISBN (Print)978-1-60511-079-0
DOIs
StatePublished - 1 Dec 2008
EventMRS 2007 - Materials Research Society - UK: 31st International Symposium on the Scientific Basis for Nuclear Waste Management - Materials Research Society, Sheffield
Duration: 16 Sep 200721 Sep 2007

Publication series

NameMaterials Research Society Symposium Proceedings
Volume1107
ISSN (Print)0272-9172

Conference

ConferenceMRS 2007 - Materials Research Society - UK
Country/TerritoryUnited Kingdom
CitySheffield
Period2007-09-162007-09-21

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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