METHOD TO ASSESS QUALITY AND BEHAVIOUR OF FUEL PELLETS IN NON-STATIONARY AND EMERGENCY MODES OF NUCLEAR REACTOR OPERATION Russian patent published in 2011 - IPC G21C3/62 

FIELD: power engineering.

SUBSTANCE: method includes heating, cooling and visual inspection of controlled pellets after tests. At that pellets are cooled down with the help of helium or other inert gas (argon, hydrogen) or argon-hydrogen mixture with subsequent assessment of pellets integrity. Behaviour of pellets at the moment of start-up and reactor power maneuvering, and also in case of unsealing and damage of fuel element shell, is registered by critical difference of temperature of heated pellets and temperature of these pellets after their cooldown, at which pellets start cracking, and also by critical difference of temperature of heated pellets and temperature of the same pellets after their cooldown, when pellets practically loose their integrity.

EFFECT: possibility to forecast behaviour and condition of pellets with certain properties in non-stationary and emergency modes of reactor operation, possibility to assess quality and behaviour of pellets with various parametres of microstructure.

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