It has been just over four years since an earthquake and subsequent devastating tsunami led to a serious accident at Japan’s Fukushima Daiichi nuclear energy facility. The flooding from the tsunami led to a loss of power and cooling capability at the facility.
Soon after the March 11, 2011 accident, the US Nuclear Regulatory Commission (NRC) set up a task force to identify the lessons that the U.S. nuclear energy industry should learn to avoid similar situations from occurring here. Based on the NRC’s findings, Duke Energy’s nuclear fleet and other nuclear power plants across the nation rolled out their emergency response plan, dubbed Diverse and Flexible Coping Strategies (FLEX).
FLEX calls for:
- Portable equipment to assure that multiple means of obtaining power and cooling water are available to support key safety functions for all reactors at a site. Equipment includes portable pumps, generators, batteries, battery chargers, compressors, hoses, couplings, tools, debris clearing equipment and other materials.
- Reasonable protection of portable equipment to guard it from the severe natural phenomena predicted for that site by locating the equipment in safe locations.
- Procedures and guidance for emergency response personnel for the use of FLEX equipment and capabilities.
- Program controls to ensure regular maintenance and testing of FLEX equipment.
- Trained personnel in FLEX capability and response.
The rationale for FLEX is that if a set of equipment is kept ready in a safe location, there would be working equipment available in the event of an emergency, no matter the disaster that befalls the facility.
Duke Energy’s FLEX Buildings
FLEX has led to changing landscapes across Duke’s nuclear fleet as one or more safe locations have been established for the FLEX equipment. McGuire Nuclear Station has three separate FLEX buildings, while Brunswick, Oconee, Robinson and Catawba nuclear stations have erected dome-shaped buildings to house equipment. Harris Nuclear Plant is using its existing Emergency Diesel Generator Building.
In addition to the new equipment housed at the individual nuclear facilities, two regional emergency centers exist in the United States to provide portable equipment in the event of a Fukushima-like event. Duke’s nuclear fleet is served by the center in Memphis, Tenn. that can respond to an emergency within 24 hours. The second facility is located in Phoenix, Ariz.
“This facility is important,” said Mike Pacilio, the executive sponsor for national response centers on the Nuclear Energy Institute’s Fukushima Response Steering Committee, when the Memphis facility opened in June 2014. “It expands our defense-in-depth safety commitment and adds tremendously to our ability to manage any extreme event.”
Equipment stored at the Memphis center includes: portable backup generators portable high pressure pumps, portable low pressure pumps, diesel fuel transfer pumps, diesel fuel tanks, diesel powered light towers, water treatment, booster pumps, electrical distribution cabinets, cables, and hoses. Each center houses five full sets of equipment, with four ready to be moved to any U.S. nuclear power plant at all times. The equipment undergoes regular testing for operability.
Commitment to Safety
“The lessons learned from this significant event have forever changed our strategies for responding to natural disasters,” said Bill Pitesa, Duke Energy’s chief nuclear officer. “Like others in the industry, we have made plant modifications to give us added confidence that we can successfully deal with severe events. We also have staged additional response equipment both locally and regionally and improved our procedures and training. Pitesa recognizes the importance of the people who work in nuclear facilities to operate the facility safely and deal with emergency situations.
“Fukushima symbolizes the nuclear industry’s unique responsibilities. While safe, reliable electric generation remains paramount, nuclear plant workers are the first line of defense should an extreme natural or other event occur. Our employees are well trained and have the experience, skills and now FLEX to deal with unexpected events.”