Search Results
Keyword：hydrogen concentration
Japan's Onagawa Nuclear Power Station Unit 2 Plans to Replace Hydrogen Concentration Monitoring Equipment
Tohoku Electric Power has consulted with Miyagi Prefecture, Ishinomaki City, and Onagawa Town in advance regarding a change to the method of monitoring hydrogen concentration inside the containment vessel under severe accident conditions at Unit 2 of the Onagawa Nuclear Power Station. The company plans to submit an application to amend the reactor installation license to the Nuclear Regulation Authority (NRA) of Japan on the 2nd. Unit 2 of the Onagawa Nuclear Power Station is located in Onagawa Town and Ishinomaki City, Miyagi Prefecture. Tohoku Electric Power previously installed a total of four hydrogen concentration detectors inside and outside the reactor containment vessel of this unit, intended to monitor changes in hydrogen concentration within the containment vessel in the event of a severe accident. In 2025, some of these detectors experienced malfunctions. In the same year...
2026-09-02
Nitrogen Supply Unit at Fukushima Daiichi Nuclear Power Station Resumes Operation After Malfunction
Tokyo Electric Power Company (TEPCO) reported on August 1 that a reactor nitrogen supply unit at the Fukushima Daiichi Nuclear Power Station malfunctioned that day, but was subsequently repaired and resumed gas supply. The company stated that during the malfunction, no significant fluctuations were observed in hydrogen concentrations inside the reactors of Units 1 to 3 or in surrounding radiation monitoring data, and no risk of hydrogen explosion was confirmed. The reactor containments and pressure vessels of Units 1 to 3 at the Fukushima Daiichi Nuclear Power Station require continuous nitrogen injection to suppress hydrogen accumulation resulting from radiolysis of water. If hydrogen concentrations exceed a certain level, the risk of hydrogen explosion may increase. According to TEPCO, at 11:14 a.m. on August 1, a worker...
2026-08-03