Basic issues of technology

Basic technological challenge of using lead as reactor coolant is assurance of such quality of the coolant (as well as that of the surfaces contacting coolant), that the following conditions are realized  

Presence of impurities in lead coolant is injurious for at least two reasons, namely  

1) possible partial or full plugging of the coolant flow cross section area, that disturbs hydrodynamics and hence heat transfer  

2) deposits formed on heat transfer surfaces (especially on the fuel elements of the reactor core causing rise of cladding temperature). 

The following impurities are present at the initial stage of circuit filling  

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