US warned on vents before failure at Fukushima plant

New York Times : Five years before the emergency vents at the Fukushima Daiichi power plant were disabled by a power failure, engineers at a reactor in Minnesota warned US regulators about the same issue, writes Matthew Wald for the New York Times. Anthony Sarrack told staff members of the Nuclear Regulatory Commission (NRC) that the venting systems at his reactor had serious design flaws: They were dependent on electric power, which could be cut in an emergency, and on human workers, who could become incapacitated. More automatic, passive systems are needed. Sarrack’s proposal was rejected by operations department officials at his company because they wanted direct control over the reactor. The NRC considered Sarrack’s warning but decided against making changes at the time, although they are now studying the events at Fukushima Daiichi with an eye toward reducing overall risk, including making vents more passive without sacrificing manually controlled systems.