Criticality alarm equipment for nuclear fuel manufacturing or preprocessing plant has three prompt criticality detectors each generating a trip signal

摘要

The equipment has three prompt criticality detectors each generating a trip signal when a prompt critical phenomenon caused by nuclear excursions is detected. The equipment includes (i) three prompt criticality detectors (1a, b, c) each generating a trip signal when a prompt critical phenomenon caused by nuclear excursions is detected, (ii) three delayed criticality detectors (8a, b, c) each generating a trip signal when a delayed critical phenomenon in which nuclear reaction increases gradually is detected, (iii) a prompt criticality judging unit (9a, b, c) receiving the trip signals from the prompt criticality detectors and judging a prompt critical phenomenon according to 2 out of 3 logic, (iv) a delayed criticality judging unit (10a, b, c) receiving the trip signals from the delayed critical detectors and judging a delayed critical phenomenon according to 2 out of 3 logic, and (v) an alarm generator (3) for processing the prompt and the delayed critical phenomenon judged by the respective criticality judging units and for generating an alarm based on the processing result.