System for determining a power generated by an assembly, nuclear reactor and method for determining the power

A system for determining a power generated by an assembly for a nuclear reactor, intended to be immersed in a heat-transfer fluid, comprising:

• a subsystem for measuring a flow rate of the heat-transfer fluid, including
• a body comprising at least one inlet, at least one outlet and at least one passage for a flow of the heat-transfer fluid from the inlet to the outlet, the passage extending from the inlet to the outlet in a longitudinal direction,
• at least one rotor disposed inside the passage and configured to be rotated, by the flow of the heat-transfer fluid, about an axis substantially parallel to a flow direction of the heat-transfer fluid in the passage, the flow direction of the heat-transfer fluid in the passage being parallel to the longitudinal direction of the passage, and
• a device for measuring a rotation speed of the rotor, wherein
• the device for measuring the rotation speed of the rotor comprises
• a module for emitting an incident light radiation having a wavelength greater than 1200 nm,
• an optical module configured to
• transmit the incident light radiation from the emission module on blades of the rotor, such that the incident light radiation is incident on the blades of the rotor in a direction substantially perpendicular to the axis of a rotation of the rotor, and
• receive a reflected light radiation, the reflected light radiation coming from a reflection, on the blades of the rotor, of the incident light radiation, and
• a first conversion module configured to determine the rotation speed of the rotor according to the reflected light radiation and determine the flow rate of the heat-transfer fluid according to the rotation speed of the rotor, and
• the system comprises
• a subsystem for measuring a temperature of the heat-transfer fluid at the inlet of the assembly and a temperature of the heat-transfer fluid at the outlet of the assembly, and
• a second conversion module configured to determine a power generated by the assembly according to at least the flow rate of the heat-transfer fluid and a difference between the temperature of the heat-transfer fluid at the inlet of the assembly and the temperature of the heat-transfer fluid at the outlet of the assembly.