riverbend


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

Nuclear Plant Emergency Preparedness: Failure to Communicate

, director, Nuclear Safety Project

Disaster by Design/ Safety by Intent #36

Disaster by Design

Nuclear plant owners are required to develop plans for responding to accidents that describe actions to be taken by workers onsite as well as describing communications to local, state, and federal organizations so they can taken actions offsite. Among other things, the emergency plans detail when to activate the sirens that warn people in the community about an accident at the plant. Read more >

Bookmark and Share

Special Nuclear Inspection: River Bend Loss of Shutdown Cooling

, director, Nuclear Safety Project

The Nuclear Regulatory Commission (NRC) sent a special inspection team to the River Bend nuclear plant near St. Francisville, Louisiana on February 8, 2016, to investigate an event in which cooling of the reactor core was interrupted for over an hour on January 10 when the reactor was shut down. The NRC’s special inspection team identified four violations of regulatory requirements characterized as Green findings, the least serious among the agency’s green, white, yellow, and red classifications.

Read more >

Bookmark and Share

Nuclear Safety inFLEXibility

, director, Nuclear Safety Project

Disaster by Design/Safety by Intent #23

Disaster by Design

Among the actions taken by the Nuclear Regulatory Commission (NRC) in response to the March 11, 2011, accident at Fukushima was to issue an order on March 12, 2012, to all U.S. nuclear plant owners requiring them to procure equipment and implement measures to enable their facilities to cope with an extended loss of normal and backup power supplies to emergency equipment. Read more >

Bookmark and Share

Flooding at the Nuclear Plant

, director, Nuclear Safety Project

Disaster by Design/Safety by Intent #1

Disaster by Design

The March 2011 disaster at the Fukushima Daiichi nuclear plant in Japan did not reveal flooding to be a nuclear safety hazard; it reminded us of this well-known threat. Flooding from internal sources (e.g., broken pipes and failed storage tanks) and from external sources (e.g., heavy rainfall and swollen rivers) had long been recognized as a risk to be managed with an array of flood protection measures. As the following summaries—an abridged sampling among many such events—indicate, there were numerous reminders before Fukushima. Read more >

Bookmark and Share