Nuclear embraces robotic technology

The nuclear industry is always searching for even safer and more efficient technologies. One such trend is the use of robotics at plant sites. Robots are used across the Duke Energy nuclear fleet as way to strengthen personal and operational safety.

RNP RobotsThe robots, however, may not look like what you imagine. Many are repurposed designs originally intended for use in war zones to search for explosive devices. They are nimble, agile, equipped with track tires that allow them to easily navigate any terrain on site and give them the appearance of miniaturized tanks with arms. The robots are equipped with several cameras allowing for multiple viewpoints.

A cultural cornerstone of the nuclear industry is strictly limiting the amount of radiological exposure nuclear workers encounter while performing work. While all radiological exposure at a nuclear facility is closely monitored and tracked, both in the short term (a single work project) and long term (over the entire career of the worker), the industry’s approach to radiation reduction is that any tool or technology that prevents worker exposure should be used. Nuclear workers could safely perform tasks without the assistance of robots, but using robots reduces or even fully eliminates exposure for many tasks.

Robots offer a number of creative solutions for limiting exposure from remote viewing of radiological areas within the plant to collecting and storing radioactive materials.

Recently, workers at Duke Energy’s McGuire Nuclear Station, located north of Charlotte,robot N.C., utilized the iRobot 710 Warrior robot (710) to lower collective radiological exposure of workers during the replacement of radioactive waste filters. These filters act in a similar fashion to your home HVAC filters, and like those filters, need to be changed on a regular basis.

Previously, removing the filters required professionals using a six-foot pole to grasp the filters and move them into temporary storage prior to transport. The same process was used for installing new filters. As you can image, using a six-foot pole to do precise work can be very challenging.

In other cases, robots simply make the work more efficient. At the Robinson Nuclear Plant, in Hartsville, S.C., robots were used to place material into storage. In order to complete this task without the assistance of robots, an enormous amount of planning and preparation would have to be performed, including the placement of barriers and other safeguards to reduce radiation exposure. By using the robots, workers were able to eliminate exposure and work more safely and efficiently.

These are just a couple of the instances, in which robots are being used throughout the Duke Energy fleet for maintenance, examination and worker protection. Robots reduce the risk of human error, providing for consistent, high-quality results. We expect the application of robots at nuclear sites will only continue to increase, as we continue to find new and innovative ways to make work safer and more efficient.

Helping for the holidays

Bike, doll, books, games, toys …

This may look like the typical wish list for any kid during the holidays but for hundreds of children and families, this wish list would be just a dream without the generosity of employees at Duke Energy’s nuclear power plants.

Hundreds of bikes, toys, games and shoes, along with needed clothing and food were donated this year to help spread a little holiday cheer. More than 1,000 children received gifts, all donated by workers at Duke’s seven nuclear plants.

Take a look at how employees in North Carolina, South Carolina and Florida shared the holiday spirit in their local communities:

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Employees at the Robinson Nuclear Plant in Hartsville, S.C., purchased more than 150 items as part of their Giving Tree drive and donated more than 1,000 boxes of cereal and macaroni and cheese to the C150arolina Kids Hunger Buster program.

At the Oconee Nuclear Station near Seneca, S.C., another 250 children had their wishes fulfilled when employees collected almost $30,000 worth of toys for the Angel Tree program.

Catawba Nuclear Station employees loaded a large truck with bikes, clothes and toys for 20 foster children with the York County Department of Social Services. An additional 150 toys and more than $1,000 were collected for Toys for Happiness.

The giving continued in Florida where employees of the Crystal River Nuclear Plant teamed up with their fossil unit teammates at the Crystal River Energy Complex for the Holiday Hope program. They delivered a truckload of toys and other gifts to the Citrus County Family Resource Center, reaching 185 children ranging from newborn to 18 years. They didn’t stop there, donating nearly 200 pounds of food to the Daystar Life Center, a local nonprofit food bank.

In North Carolina, employees of the McGuire Nuclear Station, near Charlotte, donated 160 bikes and hundreds of toys during their annual Toys for Tots drive. Nearly 100 coats were given to the Crisis Assistance Ministry, to be distributed to men, women and children through the organization’s “Free Store.”

At the Brunswick Nuclear Plant, near Southport, N.C., employees presented Brunwick County Toys for Tots with more than 100 toys and more than $3,600 in donations. Members of the plant’s security team also supported Toys for Tots by participating in Toy Rides in nearby Wilmington and Shalotte.

For the 13th straight year, employees of the Harris Nuclear Plant, near New Hill, N.C., identified and fulfilled the wish lists of 10 families from the nearby Moncure School, ranging from basic necessities like clothing, shoes and jackets, to popular toys, music, bikes and games.

Giving and sharing the spirit of the holidays is a tradition that has been honored at Duke’s nuclear power plants for years and will continue for many to come.

Why don’t all nuclear plants have cooling towers?

Water is pumped from the cooling tower basin to the plant’s condenser, and back to the cooling tower. Some of the warmth is immediately released by spraying over a grid, allowing some of the liquid to evaporate.

Water is pumped from the cooling tower basin to the plant’s condenser, and back to the cooling tower. Some of the warmth is immediately released by spraying over a grid, allowing some of the liquid to evaporate.

On a clear day, you can easily see the Harris Nuclear Plant’s 523-foot high cooling tower from downtown Raleigh, about 20 miles away. It’s become an iconic symbol of the power plant. On the other hand, if you drive 180 miles southeast to the Brunswick Nuclear Plant on the Atlantic coast in Southport, N.C., you won’t see a cooling tower.

Since both are nuclear power plants, why does only one have a cooling tower?

First, let’s review the purpose of a cooling tower. All thermoelectric power plants that use heat to make steam to drive a turbine generator need a system to cool water. The majority, including Harris and Brunswick, use a once-through cooling system, where water is drawn from a lake, river or reservoir. The difference between Harris and Brunswick is really based on their location and the source of cooling water.

Second, it is important to note that the cooling systems at both plants are designed for plant cooling and to protect the environment. In fact, the use of cooling towers for new power plants larger than 100 megawatts (MW) was mandated by the Clean Water Act of 1972 to protect the aquatic life in the river or lake from which the cooling water is taken.

Harris Lake, with a surface area of 4,100 acres, was constructed to provide cooling water for the Harris Plant. Water is pumped from the lake into the cooling tower basin. Water from the cooling tower basin circulates through the plant’s condenser, absorbs heat from the steam and travels back to the cooling tower. The water is then sprayed onto a grid in the center of the cooling tower. Cool air flows up from the center, which is hollow, and passes the warm falling water.

To complete the cycle, a discharge pipe returns water to Harris Lake within a degree or two of the lake’s normal temperatures. This ensures there is no harm to the fish in Harris Lake. The lake is popular for sport fishing, boating and water skiing.

The cooling process is similar at the Brunswick Plant, except for the source and size of the source of water. Instead of drawing water from a manmade lake into a cooling tower basin, the water is pumped into the plant’s condensers directly from the Cape Fear River. The warm water is then discharged and cooled as it travels more than five miles through a manmade discharge canal until it finally meets its destination – the Atlantic Ocean! The warm water quickly dissipates in the ocean, causing no harm to the aquatic environment (and actually makes quite the fishing spot for local anglers).

The Brunswick Nuclear Plant’s two reactors came online in 1975 and 1977, and Harris, which has one reactor, began operating in 1987. Today, it is more likely that cooling towers would be required on all new nuclear plants to meet environmental regulations than in the early 1970s, when the Brunswick Plant was under construction. In fact, only two of Duke Energy’s six operating nuclear sites use cooling towers. All five new reactors currently under construction in the U.S. include the use of cooling towers.

Just the Facts:

  • Cooling towers are constructed for plant cooling and to protect aquatic environments.
  • The nuclear reactor is located inside a containment building, not the cooling tower.
  • The cloud at the top of cooling tower is not radioactive. The water in the reactor stays in a closed system, never coming into contact with the water in the cooling tower.
  • There are more than 250 cooling towers on power plants across America, and fewer than 100 on nuclear plants.
  • Among the Duke Energy nuclear fleet, only two plants — Harris and the Catawba Nuclear Station — use cooling towers.  The other sites (McGuire Nuclear Station, Oconee Nuclear Station and the Robinson Nuclear Plant) all use large manmade lakes as makeup water for plant cooling.