Clean Core began the experiment in the Advanced Test Reactor at INL 2024, targeting burnup of up to 60 gigawatt-days per metric ton of uranium (GWd/MTU). According to the company, its final tests exceeded that goal, which it said represented “more than eight times the typical discharge burnup” of traditional PHWRs and CANDU (Canadian deuterium-uranium) reactors.
Made of a blend of thorium and HALEU, ANEEL aims to decrease operating costs, reduce high-level waste volumes, increase safety margins, and improve proliferation resistance.
The experiment tested 216 ANEEL fuel pellets, extracting them from the ATR in three batches, first at the 20 GWd/MTU target, then at over 45 GWd/MTU, and now at over 60 GWd/MTU. The tests simulate the fuel performance under extended reactor operation.
The final fuel batch has yet to be analyzed, but according to Clean Core, the postirradiation examination (PIE) results it has from the experiment so far “are consistent with findings reported in the literature and suggest that ANEEL fuel performs well, with some test rodlets exhibiting superior fission gas retention compared to traditional UO2 [uranium dioxide] fuel.”
The company said its next step to commercializing ANEEL is a demonstration irradiation in a commercial power reactor.
They said it: “This final portion of the irradiation experiment has been several years in the making, and I congratulate Clean Core on their major accomplishment. This has been an exciting project to support, and I’m eager to see what can be learned from the upcoming high-burnup sample PIE results,” said Kelley Walker, principal investigator for Clean Core’s irradiation campaign at INL.
"Surpassing 60 GWd/MTU of burnup in the Advanced Test Reactor marks an important milestone for the ANEEL fuel program,” said Mehul Shah, CEO of Clean Core. “This irradiation campaign provides meaningful performance data and demonstrates that thorium-HALEU fuel can achieve burnup levels comparable to those seen in PWR fuels while offering improved fuel utilization, enhanced safety characteristics, inherent proliferation resistance, and meaningful reductions in long-lived nuclear spent fuel radioisotopes. Our objective has been to introduce thorium into the nuclear fuel cycle in a practical way using existing reactors, and this milestone represents a significant step toward that goal.”
