NRC: Nuclear plant failure not our fault UT San Diego, By Morgan Lee .APRIL 10, 2015 As it turns the page on the breakdown of the San Onofre nuclear plant, the U.S. Nuclear Regulatory Commission is standing by its role in overseeing the replacement of steam generators that led to a radiation leak and the facility’s early retirement in 2013.
The safety agency also is warning the nuclear power industry that the destructive vibrations among generator tubes carrying radioactive water that occurred at San Onofre could emerge at other reactors over time.
A detailed memo by nuclear commission staff on the lessons learned at San Onofre has concluded that efforts by plant operator Southern California Edison to avoid a more-detailed review of the generators by safety regulators are not necessarily to blame in the breakdown of the plant. Responsibility lies instead with design mistakes overseen by Edison, according to the 70-page memo quietly released last month……..
The commission is directing the nuclear power industry to revise design guidelines that do not sufficiently address the kind of destructive tube vibrations that disabled the replacement generators at San Onofre.
A letter from the agency to industry engineers last year warned that “events at San Onofre not only raise questions about industry standards for designing and fabricating steam generators, but also raise questions about the operation of existing steam generators.” It cited no immediate safety concerns but said active generators could become susceptible as conditions change.
A 2012 radiation leak at San Onofre was traced to rapid wear on generator tubes that carry radioactive water that circulates through the reactor core.
Meanwhile, the nuclear commission is preparing to dismiss formal accusations that a more-thorough safety review of the San Onofre generators was warranted. That complaint was filed by the environmental group Friends of the Earth in 2012……….http://www.utsandiego.com/news/2015/apr/10/nrc-stands-by-process-at-onofre/
