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UCS to Nuclear Regulatory Commission: Big THANKS!

, director, Nuclear Safety Project

This spring, I ran into Mike Weber, Director of the Office of Nuclear Regulatory Research for the Nuclear Regulatory Commission (NRC), at a break during a Commission briefing. The Office of Research hosts a series of seminars which sometimes include presentations by external stakeholders. I asked Mike if it would be possible for me to make a presentation as part of that series. Read more >

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Nuclear Reactors and Flood Protection

, director, Nuclear Safety Project

Disaster by Design/ Safety by Intent #48

Safety by Intent

Oconee Flood Protection Issue

In August 2006, NRC inspectors identified a deficiency in a flood protection measure at the Oconee Nuclear Station in South Carolina. Specifically, the inspectors discovered that workers removed a 6-inch by 10-inch panel in the 5-foot tall flood wall around the Standby Shutdown Facility (SSF) to allow temporary cables to be used during a modification. When the work was completed and the cables removed, the panel was not re-installed.

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Nuclear Plant Containment Failure: Overpressure

, director, Nuclear Safety Project

Disaster by Design/Safety by Intent #30

Disaster by Design

Defense-in-depth is a primary element of the Nuclear Regulatory Commission’s approach to the safety of U.S. nuclear power plants. Many of the NRC’s regulatory requirements seek to reduce the chances of reactor core meltdowns to as low as achievable levels. But recognizing that the consequences of low probability events like meltdowns, sometimes called “black swans,” can be disastrous, the NRC also has regulatory requirements seeking to reduce the chances that radioactivity gets released in harmful amounts during an accident. This commentary describes the primary containments used in pressurized water reactors (PWRs) and boiling water reactors (BWRs) and how too much pressure can cause containment to fail. Read more >

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Longstanding Nuclear Safety Impairments

, director, Nuclear Safety Project

Disaster by Design: Safety by Intent #8

Disaster by Design

Individuals applying for health insurance are often asked to first undergo a medical examination. The premium rates charged by insurance companies for health care coverage are established based on statistics. If an individual has a pre-existing condition (like a festering gunshot wound to the abdomen), that person might require more medical attention than the statistics would otherwise suggest. Insurance companies rely on medical examinations to lessen the “surprise factor” of pre-existing conditions and set premium rates that provide the coverage the customers need and the profit the companies need.

Longstanding nuclear safety impairments are pre-existing conditions that undermine the plant’s health. Read more >

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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 >

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