About the project

Design and safety analysis of lead-cooled reactors

The application of lead-cooled reactors with passive means for decay heat removal may allow to improve the economy of commercial nuclear power production, or to permit efficient and safe recycle of spent nuclear fuel.

To this end, the division of nuclear engineering is designing small lead-cooled fast reactors (LFR) for commercial power production in remote areas and/or areas with weak power grids. These reactors would rely on natural convection of the primary coolant for decay heat removal and radiation of heat through the vessel as an ultimate heat sink. In order to remain economically competitive on their respective market, this class of reactors will utilise uranium based fuels. In a first step, conventional oxide fuel will be applied, to be substituted with uranum nitrides, once the latter have been qualified for commercial use.

In order to demonstrate the LFR technology, the division is designing a lead-cooled research reactor to be deployed in Oskarshamn, Sweden. This work is conducted together with a number of academic and industrial partners within the SUNRISE project, funded by the Swedish Strategic Research Foundation ( SSF ). The project includes the following work packages:

1. Design and safety analysis
2. Development of alumina forming steels
3. Advanced manufacturing and characterisation techniques
4. UN fuel development
5. Experimental evaluation of erosion and thermal hydraulics

Moreover, the application of small Generation-IV lead-cooled reactors for transmutation of nuclear waste is investigated for application in countries with a legacy of spent nuclear fuel. These reactors would use (U,Pu,MA)N fuel manufactured by spark plasma sintering, a technique developed by the division in a related project.

The tools used in the project include the Monte-Carlo code Serpent for neutronics and burnup, the in-house code BELLA for safety informed design of the primary system, the system code SAS for detailed transient analysis and the RSAC code for assessment of radiological impact of severe accidents. Within the frame of the project, the capabilities of BELLA are currently extended to include thermo-mechanical performance of fuels.

Peer reviewed journal publications resulting from the project:

• Sara Bortot, Erdenechmig Suvdantsetseg & Janne Wallenius, BELLA: a multi-point dynamics code for safety-informed design of fast reactors, Annals of Nuclear Energy 85 (2015) 228.