The TruPro® sampling & characterization of ANDRA Concrete Radioactive Waste Hull Containing Sludge Immobilized by a Hydraulic Binder Highlights

The French National Radioactive Waste Management Agency (ANDRA) is currently undergoing development of radwaste package quality qualification and there was a need to sample a radioactive waste hull. The purpose of sampling was for radiological and chemical analyses to thus characterize the radioactive contents of the waste block and check the block’s homogeneity in conformance to French waste acceptance criteria and regulations.  By sampling the block using TruPro® the number of representative samples collected was maximized whilst minimizing the total quantity of extracted material and also minimized the physical degradation of the package during sampling operations.

NMNTI obtained samples from the waste block ion-exchange resin (IERs) subsurface materials to be analyzed for Mn-54, Co-60, Ag-108m, Ag-110m, Sb-125, Sn-126, Na-22, Nb-94, Cs-134 and Cs-137 gamma nuclides for these samples in close proximity to sampling operations.  The ANDRA waste block sampling work took place at the Société des Techniques en Milieu Ionisant (STMI) TRIADE facility in a large intervention cell located at the STMI TRIADE Site, Site du Sactar, 84500 Bollène, France.  The sampling of the radioactive waste block ascertained the NMNTI ability to acquire dry samples from the waste package and ascertain the homogeneity of the waste block material with respect to Mn-54, Co-60, Ag-108m, Ag-110m, Sb-125, Sn-126, Na-22, Nb-94, Cs-134 and Cs-137 and difficult to measure radionuclides and heavy metal elements of the waste package.

The sampling of the waste block is a visible project of critical relevance and interest to ANDRA constituting valuable experience on the radioactive waste sampling and radioactive packaging quality stage.  ANDRA, NMNTI and STMI TRIADE designed and performed the project using radiological and conventional safety as the paramount driving factor to move the sampling effort forward, utilizing detailed planning of sampling methodologies aimed at minimizing risks to people and the environment.
Work took a total of 13 working days.  A total of 48 resin samples were easily retrieved,Collected all organic polymer particulate from sampling operations into specialized filter units with no risk or spread of contamination. The procedural methodologies to sample and analyze powdered IERs radwaste package samples acquired dry from the ANDRA radioactive waste hull using the TruPro® system and approach were adhered to.

Successful TruPro® sampling effectively accomplished the following:

  • Operated without the use of liquid, to retrieve dry representative powdered samples,
  • Powered by a facility electric supply coupled to 30 meter electrical extension cables,
  • Removal of 150 mm inactive concrete plug cap powdered samples using a 19 mm diameter drill bit from 8 sampling locations,
  • Removal of 40 mm thick S235 JR grade metal biological protection layer powdered and chipped samples using an 18 mm diameter metal cutting drill bit from 8 sampling locations,
  • Removal of 6 representative samples at an incremental depth of between 120 - 140 mm of radwaste hull IER-epoxy based organic polymer mixture samples using a 15 mm diameter drill bit from predetermined 8 sampling point locations sequentially to depth, traversing and profiling to the bottom of the inner metal biological protection.
  • Collected all volatile radionuclides and fugitive tritium into specialized traps (one for all sampling operations) and;
  • A maximum total depth of 1080 mm was traversed in all 8 sampling locations.
  • Important physical and spatial configurational information were gained about the hull.
  • Retrieved incremental samples of resin were in a powdered form.

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