Description
Following the Fukushima accident, the nuclear industry has accelerated the development of Accident Tolerant Fuel (ATF) technologies aimed at enhancing fuel safety and performance. This includes exploring advanced cladding materials such as chromium-coated Zircaloy, silicon carbide (SiC), and iron-based alloys like FeCrAl and stainless steel (SS), which offer improved resistance to high-temperature steam reactions that generate hydrogen.
In addition to cladding, fuel material innovation is also critical. Traditional uranium dioxide (UO₂) suffers from low thermal conductivity and limited heavy metal density, limiting its performance. While additives like beryllium oxide (BeO) can improve thermal conductivity, they reduce heavy metal content. Alternatively, fuels such as uranium silicide (U₃Si₂), uranium nitride (UN), and uranium carbide (UC) offer higher heavy metal density and better thermal properties, enabling extended cycle lengths without increased enrichment.
There is a strong interest in the United Arab Emirates (UAE) to extend APR-1400 reactor cycles from 18 to 24 months. This study evaluates U₃Si₂ as an ATF candidate for APR-1400, highlighting its 16.5% higher heavy metal content and favorable thermal conductivity behavior compared to UO₂. However, the increased initial reactivity from U₃Si₂ requires effective reactivity control measures. To this end, the High Gadolinium (HIGA) burnable absorber concept is investigated as a potential solution to suppress excess reactivity, reduce soluble boron requirements, and avoid issues like a positive moderator temperature coefficient.
| Technical Track | Reactor Physics |
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