What does SEALER mean?
SEALER stands for "Swedish Advanced Lead Reactor”. It also means ”Person providing a stamp of quality”.
Isn't lead poisonous?
Yes, but common food items, such as cheese, also contain significant amounts of lead. Lead is used in many every day items, such as car batteries, crystal glass and jewellery. With adequate barriers, such as the vessel and confinement, the lead used in SEALER is not a safety issue.
What is the advantage of SEALER, as compared to other lead-cooled reactor concepts?
SEALER is designed to operate at a much lower power density, which means that
a) The maximum temperature of structures is lower, dramatically reducing corrosion rates
b) The life-time of the fuel is longer, meaning that no fuel reloading operations nor fuel storage pools are necessary on the site of the reactor.
How does the safety of lead reactors compare to that of gas cooled high temperature reactors?
The coated particle fuel of HTRs can withstand higher temperatures than the steel clad fuel of LFRs. However, should there be a release of fission products from the fuel, the helium coolant of HTRs does not constitute a barrier for further release. The weak point of an HTR, from the perspective of safety, is the primary vessel.
Why do we not take advantage of the lower melting temperature of lead-bismuth alloys?
Bismuth transmutes into highly radio-active polonium-210 under neutron exposure, which means that the coolant itself contributes to the so-called source term in case of an accident. The frequency of accidents leading to release of coolant is higher than for the ones releasing fission products.
What about thorium fuels for SEALER?
For starting up a fast reactor, thorium fuels require the use of either separated plutonium or highly enriched uranium-235, neither of which are available for commercial reactor projects. Moreover, thorium fuels are very difficult and costly to reprocess using current technology.
© LeadCold Reactors, 2021