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Bringing Fire Protection Into Focus

Daniel Frumkin
Senior Fire Protection Engineer
 

The NRC’s fire protection staff and graphic artists have worked together to create a new introduction to our website’s fire protection pages. The illustrations for the “Prevention,” “Suppression” and “Safe Shutdown” tabs highlight the details in each area of fire protection.

Fire Protection infographic_r11Prevention is a combination of training, NRC inspections and procedures to keep potential fire starters such as welding under control. U.S. reactors have improved their prevention efforts over time. In 1985 they reported 22 significant fires. By the late 1990s, even though more reactors were running, the annual reporting numbers had fallen by more than half. In 2011 U.S. plants reported only six significant fires – less than one fire for every 10 operating reactors.

The next layer of protection involves fighting fires if they occur at or near a reactor. Plants’ fire detection systems are a lot like the smoke detectors in your house. When these detectors go off, however, trained firefighters show up with extinguishers and fire hoses. Many key plant areas also have automatic sprinkler systems. Plants also have plenty of firefighting water available and can get that water onto a fire using onsite staff and equipment or fire engines from nearby communities.

Even with all these measures, U.S. plants must still be able to safely shut down if a fire breaks out. The fire protection approach puts barriers between each reactor’s multiple sets of shutdown equipment, so a fire can’t disable all the equipment at once. The power and control cables are separated to make sure that those systems are available to shut the plant down.

Plants also have alternate control stations if fires disrupt the control room’s ability to manage the situation. The plants have emergency power sources, both installed large diesel generators and portable equipment the NRC required after 9/11. These sources help ensure fires outside the reactor can’t deprive systems of the electricity they need.

Check out the new graphics and fire protection web pages. We hope this information makes the topic easier to understand and gives you a better sense of how layers of protection help ensure nuclear plants remain safe from fires.

4 responses to “Bringing Fire Protection Into Focus

  1. richard123456columbia February 14, 2014 at 12:53 pm

    Speaking generally, spent fuel pools are built to the same standards as the reactors, so the pools can safely withstand extreme events. Burning fuel of any type on top of a spent fuel pool’s water would present very little risk to the fuel
    If fire above fuel pool but if plane is guided through the tin roof into the fuel pool smashing bundles into each other causing a fire from a nuclear reaction, how can fire fighter get close or into the building with out a lead suit so heavy they can not walk.

  2. Rich February 14, 2014 at 8:57 am

    Thanks for the information on the fire protection features of nuclear power plants.
    I have one concern involving the adequacy of fire protection measures in the event of an aircraft crash into a plant’s spent fuel pool. An aircraft crash into a spent fuel pool not only represents a large missile hazard to fuel stored in the spent fuel pool but also results in a massive aviation-fuel fed fire in the entire Auxiliary Building of the plant. Such a fire would threaten redundant safety systems and equipment relied on for safe shutdown of the plant. Furthermore, manual fire fighting efforts would be impossible not only due to the massive fire but also due to the large amount of radioactivity in the Auxiliary Building itself. Please advise as to measures in place to cope with such an unlikely but devastating event.

    • Moderator February 14, 2014 at 10:33 am

      We briefly mentioned the agency’s post-9/11 actions in the blog post, so here’s more detail. After 9/11 the NRC conducted in-depth analyses of scenarios that could disable large areas of a nuclear power due to fires and explosions. These are security-related analyses, so we can only say the results show U.S. nuclear power plants of any design will very likely survive a large aircraft impact and continue to keep the public safe. To enhance that survivability, after 9/11 the NRC required all U.S. reactors to put in place procedures and equipment to maintain key safety functions even after large fires and explosions. These measures are security-related so details are unavailable. These post-9/11 measures have, however, been further strengthened by the NRC’s post-Fukushima response.

      Speaking generally, spent fuel pools are built to the same standards as the reactors, so the pools can safely withstand extreme events. Burning fuel of any type on top of a spent fuel pool’s water would present very little risk to the fuel.

      Scott Burnell

      • Rich February 15, 2014 at 1:48 pm

        Thanks for the prompt informative response.
        Burning fuel of any type on top of the spent fuel pool’s water I agree poses little risk to the fuel therein. However burning fuel of any type throughout the entire Auxiliary Building is a different matter. Even 3-hour rated fire barriers would be no match for the intense heat created by such a fire. As 9/11 demonstrated even structural steel is no match for such a fire.

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