NRG to collaborate on Swedish lead-cooled reactor 16 April 2018 16 April 2018

Netherlands-based NRG announced on 11 April that it had begun a multi-year collaboration for safety analysis of the SEALER (Swedish Advanced Lead Reactor) – a small modular lead cooled reactor under design by Sweden’s LeadCold for deployment in remote arctic regions in Northern Canada. Both companies will compare their independent safety analyses.

NRG said it intends to use advanced 3-dimensional simulation techniques to confirm the feasibility of certain design safety features that cannot be evaluated using conventional simulation techniques. In the long term, LeadCold intends to construct an electrically heated model of their reactor that should allow additional experimental verification of the advanced design safety features as applied by NRG.

NRG project manager Ferry Roelofs said the collaboration would test the advanced simulation techniques at NRG as part of the Dutch national R&D programme. LeadCold CEO Janne Wallenius noted NRG’s advanced simulation techniques should confirm that the safety of the reactor is improved and would “help in convincing safety authorities about our approach". Nuclear services company NRG operates the High-Flux Reactor at Petten in the Netherlands, while LeadCold, founded in 2013 with its head office in Stockholm and a Canadian subsidiary, is a spin-off from the Royal Institute of Technology in Stockholm.

SEALER is a lead-cooled reactor designed with the smallest possible core that can achieve criticality in a fast spectrum using 19.9% enriched uranium oxide fuel. The rate of electricity production may vary from 3MWe to 10MWe, giving a core-life 10-30 full power years (at 90% availability). The SEALER reactor is designed to maintain a maximum temperature of the lead coolant below 450°C, making corrosion of fuel cladding and structural materials a manageable phenomenon, even over a life-span of several decades.

The safety features of lead mean that the core can withstand a complete loss of off-site power for weeks before the integrity of the fuel rods is challenged, LeadCold said on its website. If any volatile fission products are released into the coolant, 99.99% will be retained by the lead. Also, the eventual release of noble gases and residual volatiles results in a radiological exposure at the site boundary which is smaller than the natural background dose received over a few months. “Hence, no accident scenario can lead to a situation where evacuation becomes necessary,” LeadCold said.

LeadCold entered Phase 1 of the Canadian Nuclear Safety Commission’s pre-licence review in December 2016. The eventual objective is to receive a licence for construction in Canada by the end of 2021, intending to having the first SEALER-unit ready for operation in 2025. The future cost of the reactor is estimated at CAD100m ($79m).



Photo: A 3D-CAD representation of SEALER (Source: LeadCold)