susquehanna


The “Race” to Resolve the Boiling Water Reactor Safety Limit Problem

, director, Nuclear Safety Project

General Electric (GE) informed the Nuclear Regulatory Commission (NRC) in March 2005 that its computer analyses of a depressurization event for boiling water reactors (BWRs) non-conservatively assumed the transient would be terminated by the automatic trips of the main turbine and reactor on high water level in the reactor vessel. GE’s updated computer studies revealed that one of four BWR safety limits could be violated before another automatic response terminated the event.

Over the ensuring decade-plus, owners of 28 of the 34 BWRs operating in the US applied for and received the NRC’s permission to fix the problem. But it’s not clear why the NRC allowed this known safety problem, which could allow nuclear fuel to become damaged, to linger for so long or why the other six BWRs have yet to resolve the problem. UCS has asked the NRC’s Inspector General to look into why and how the NRC tolerated this safety problem affecting so many reactors for so long. Read more >

Bookmark and Share

Commendable Nuclear Safety Catch at the Susquehanna Nuclear Plant

, director, Nuclear Safety Project

The owner of the two boiling water reactors (BWRs) at the Susquehanna Steam Electric Station in northeastern Pennsylvania notified the Nuclear Regulatory Commission (NRC) on April 2, 2018, that workers’ mistakes rendered an emergency core cooling system on Unit 1 vulnerable to being disabled by an earthquake at the same time that another emergency core cooling system was out of service for work on its power supply system. This is good news—not in having two safety systems impaired while the reactor operated, but in how quickly the problem was detected and corrected. Read more >

Bookmark and Share

UCS Causes Meltdowns at US Nuclear Reactors (no, really)

, director, Nuclear Safety Project

Disaster by Design/ Safety by Intent #46

Disaster by Design

You won’t see it on our website. You won’t find it in materials we mail out to our members. You won’t hear it in the webinars we hold for prospective donors. But UCS caused a meltdown at a U.S. nuclear power reactor. Well, that’s only half the story. UCS caused meltdowns at two U.S. nuclear power reactors. In our defense, they (being the Nuclear Regulatory Commission (NRC) and the nuclear industry, started it. We only finished it. Read more >

Bookmark and Share

Nuclear Plant Containment Failure: Isolation Devices

, director, Nuclear Safety Project

Disaster by Design/Safety by Intent #32

Disaster by Design

Containment structures at nuclear power plants have multiple purposes. Containments protect vital safety equipment from damage caused from external events like high winds and the debris they can fling. And containments protect nearby communities against radiation released from reactor cores damaged during accidents. Read more >

Bookmark and Share

Severe Accident Management Guidelines for Nuclear Plants

, director, Nuclear Safety Project

Disaster by Design/Safety by Intent #22

Disaster by Design

The March 1979 accident at the Three Mile Island nuclear plant near Harrisburg, Pennsylvania showed that the procedures used by workers in responding to accidents could be significantly improved. Read more >

Bookmark and Share