Ikata Nuclear Power Station Unit 3 in Japan briefly deviated from operational limits due to abnormal signals in protection system instrumentation
Shikoku Electric Power Co. reported on August 27 that abnormal signals from safety protection system instrumentation appeared in the central control room of Ikata Nuclear Power Station Unit 3, which was in normal operation, indicating that one channel of the overtemperature ΔT related instrumentation was unreliable. The operator determined at 22:10 on August 26 that the unit had deviated from the operational limits stipulated in the Reactor Facility Security Regulations. On-site confirmation showed that the unreliable signal originated from 1 of the 4 channels of the overtemperature ΔT protection function. Overtemperature ΔT is one of the reactor automatic trip elements, used to protect in-core fuel; its limit value is calculated based on parameters such as reactor power, pressurizer pressure, and...
2026-08-27
