Sustainability Times has reported on an incident that occurred at EDF’s Golfech NPP in June that led to an 18-hour interruption of a critical cooling system. A critical error was narrowly averted when a technician mistakenly closed the wrong cooling valve, leading to an 18-hour shutdown of a crucial cooling system. “Although the incident was resolved without any harmful outcomes, it underscores the importance of enhanced safety protocols and constant vigilance.” Fortunately, the mistake was detected and rectified within 30 minutes of discovery, preventing severe consequences. Sustainability Times said its report was “based on verified sources”.
This reflects a similar incident in October 2019. The French Nuclear Safety Authority (ASN) said a significant safety incident had occurred during primary circuit drainage operations at Golfech unit 2. The incident was classified at level 2 of the International Nuclear and Radiological Event Scale (INES) scale.
During a scheduled outage, a field operator visited the reactor building to open the pressuriser vent in accordance with procedures but was interrupted and the vent was not opened. However, thinking that it had been opened, operators in the control room began the planned primary system drainage operations, with the vent closed, leading to depressurisation of the circuit.
Eight hours later, an operator noticed the discrepancy. After analysis, the operating team interrupted the drainage of the system and sent an operator to the reactor building to check the position of the pressuriser vent. It was then opened “without first carrying out the steps required by the general operating rules”. This resulted in uncontrolled water movements in the primary circuit and a drop in the water level.
However, ASN said: “Owing to the degraded safety functions and the potential consequences for nuclear safety, notably linked to errors in the management of the event and the monitoring of the operation activities, as well as to the fact that insufficient lessons had been learned from operating experience feedback, the event is rated level 2 on the INES scale.”
According to ASN, 2019 “was also marked by the declaration of numerous significant events for security”. Eight events occurred during the planned shutdown of reactor 2, including the INES level 2 one. In terms of radiation protection, ASN “noted unacceptable situations, particularly in controlling the radiological cleanliness of potentially contaminated premises and, in terms of environmental protection, ASN noted “untimely releases of non-radioactive substances”, including one which spilled into the Garonne. Golfech had already been the subject of a critical 2018 assessment with ASN saying the quality of the operation had “degraded”.
