PROTECTION SYSTEM OF A NUCLEAR REACTOR IN CASE OF THE LOSS OF AN ANTIRREACTIVE ELEMENT.

摘要

THE PROTECTION AGAINST THE CONSEQUENCES OF THE ACCIDENTAL FALL OF A CLUSTER OF CONTROL BARS IS ASSURED BY FOUR CHAINS, EACH TWO CHECKING NEUTRONIC FLOW DETECTORS (D1A, D1B), TWO PRIMARY TREATMENT CIRCUITS (R1A, S1A AND R1BO, S1). TO THESE TWO DETECTORS TO SUPPLY EACH ONE PRIMARY SIGNAL OF FALL IN CASE OF FAST DECREASE IN FLOW MEASURED BY THE CORRESPONDING DETECTOR, AND A DOOR (P1) OF THE OU TYPE TO SUPPLY A SIGNAL OF DROP BY THE CHAIN IN THE PRESENCE OF THE LESS A PRIMARY SIGNAL. THE DETECTORS (D1A, D4B, D3A, D1B, D2A, D3B, D4A AND D2B) ARE ANGULARLY DISTRIBUTED AROUND THE VERTICAL AXIS (A) OF THE HEART (2). A SECONDARY TREATMENT CIRCUIT (6) SENDS AN EMERGENCY STOP OF THE REACTOR WHEN IT RECEIVES SIGNS OF THE FALL DUE TO THE EXIT OF AT LEAST TWO CHAINS.