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Anticipated Transient Without Scram

, former director, Nuclear Safety Project

Role of Regulation in Nuclear Plant Safety #8

In the mid-1960s, the nuclear safety regulator raised concerns about the reliability of the system relied upon to protect the public in event of a reactor transient. If that system failed—or failed again since it had already failed—the reactor core could be severely damaged (as it had during that prior failure.) The nuclear industry resisted the regulator’s efforts to manage this risk. Throughout the 1970s, the regulator and industry pursued non-productive exchange of study and counter-study. Then the system failed again—three times—in June 1980 and twice more in February 1983. The regulator adopted the Anticipated Transient Without Scram rule in June 1984. But it was too little, too late—the hazard it purported to manage had already been alleviated via other means. Read more >

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

, former 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 >

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Tennessee Valley Authority’s Nuclear Safety Culture Déjà vu

, former director, Nuclear Safety Project

The Nuclear Regulatory Commission (NRC) issued a Confirmatory Order to the Tennessee Valley Authority (TVA) on July 27, 2017.  An NRC team inspecting the Watts Bar Nuclear Plant in fall 2016 determined that TVA failed to comply with elements of another Confirmatory Order that NRC had issued to TVA on December 22, 2009. Specifically, the 2009 Confirmatory Action required TVA to implement measures at all its nuclear plant sites (i.e., Watts Bar and Sequoyah in Tennessee and Browns Ferry in Alabama) to ensure that adverse employment actions against workers conformed to the NRC’s employee protection regulations and whether the actions could negatively impact the safety conscious work environment. The NRC inspection team determined that TVA was not implementing several of the ordered measures at Watts Bar. Read more >

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Turkey Point: Fire and Explosion at the Nuclear Plant

, former director, Nuclear Safety Project

The Florida Power & Light Company’s Turkey Point Nuclear Generating Station about 20 miles south of Miami has two Westinghouse pressurized water reactors that began operating in the early 1970s. Built next to two fossil-fired generating units, Units 3 and 4 each add about 875 megawatts of nuclear-generated electricity to the power grid.

Both reactors hummed along at full power on the morning of Saturday, March 18, 2017, when problems arose. Read more >

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TVA’s Nuclear Allegators

, former director, Nuclear Safety Project

The Nuclear Regulatory Commission (NRC) receives reports about potential safety problems from plant workers, the public, members of the news media, and elected officials. The NRC calls these potential safety problems allegations, making the sources allegators. In the five years between 2012 and 2016, the NRC received 450 to 600 allegations each year. The majority of the allegations involve the nuclear power reactors licensed by the NRC. Read more >

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