METHOD OF CONTROLLING NUCLEAR POWER PLANT WITH PRESSURISED WATER REACTOR WITH VARIATION OF REACTOR POWER OR EXTERNAL LOAD Russian patent published in 2012 - IPC G21C7/00 

FIELD: physics, nuclear.

SUBSTANCE: invention relates to nuclear power and can be used to control a nuclear power plant with a pressurised water reactor with variation of the reactor power or external load. The method involves maintaining axial offset in the reactor core. When reactor power falls, boric acid is simultaneously added to the primary coolant and the working group of adjusting controls of the system for controlling and protecting the reactor core according to a proportional law of adjustment, and steam pressure in the main steam header and steam generators is increased. Upon achieving a given intermediate power level, supply of boric acid is cut and a "pure distillate" is fed into the primary loop, and boric acid is fed once the maximum of the "iodine pit" is passed. To increase reactor power to a new stationary level, "pure distillate" is added to the primary coolant while also removing the working group of adjusting controls from the reactor core according to a proportional adjustment law, and steam pressure is increased to a value which ensures constant temperature of the coolant at the input of the reactor.

EFFECT: high stability of the power density field in the reactor core, longevity of fuel-element jackets, fewer control inputs and higher reliability of the reactor control system during power manoeuvring.