Dry Cask Storage: An Alternative for Storing Used Fuel

McGuire Nuclear Station dry cask storage stores spent fuel on site.

McGuire Nuclear Station dry cask storage stores used fuel on site.

One aspect of nuclear energy that makes it unique is the issue of used fuel storage.  Used fuel is nuclear fuel that is no longer useful for sustaining a chain reaction in a reactor.  While the fuel is no longer useable for producing electricity, it continues to give off radiation and heat and must be stored properly.

The United State government has promised electric utilities it will create a long-term storage solution for used fuel, but that has not yet came to fruition. The Nuclear Regulatory Commission has selected Yucca Mountain as a potential disposal site but has been contested.  Until the government makes a decision regarding the long-term storage location of spent fuel, nuclear facilities are either store it onsite or send it to specially equipped landfills. While a central repository for used nuclear fuel is the long-term goal, nuclear facilities are well equipped to safely handle the storage of used fuel on site.

After being removed from the reactor, used fuel spends approximately five to ten years in a large, deep pool of water on site known as a used fuel pool. The water cools the fuel and acts as a radiological barrier. Once the fuel cools down to an appropriate temperature and meets strict radiological and chemical requirements, it is moved to dry cask storage.

The cask is a round, stainless steel canister that holds approximately 24 used nuclear fuel bundles. Dry cask storage means exactly that – dry. The water that is in the cask when it is loaded with fuel is pumped out through siphon ports and backfilled with helium to ensure it is dry. It is protected by a reinforced concrete building called a horizontal storage module.

The fuel is permanently cooled through a system of natural circulation. The horizontal storage module has vent ports located in the front of each module that allow air to flow around the canister and back out again. In addition, nuclear professionals monitor the modules by performing observations and using radiation and temperature monitors.

The Birds. At Duke Energy’s Nuclear Plants

Image

Birds migrate for the winter. But where do they migrate? Would you believe more than 150 species migrate to North and South Carolina? And many of those nest near or on the lakes that Duke Energy’s nuclear plants sit on.

At McGuire Nuclear Station on Lake Norman, the rufus hummingbird, red-necked grebe, western grebe, and black tern have been spotted.

tern

Terns have been spotted near McGuire Nuclear Station on Lake Norman.

At Catawba Nuclear Station on Lake Wylie, brown pelicans have been spotted.

“Birds species from bald eagles to ruby-throated hummingbirds nest along the shores of the Catawba River Corridor and surrounding areas,” said Duke Energy Environmental Scientist Mark Auten. “There are a number of birds that frequent the Carolinas during the winter season that are not traditionally found in this area year-round.”

For example, the common loon spends the winter months fishing on many of the Catawba lakes,  as do several species of gulls. And many wading birds such as herons and egrets can be seen in the shallows around all the lakes and nesting on many islands and along the shore lines — often in pine trees.

An osprey cam is being installed at Catawba Nuclear Station for the public to watch the osprey nesting.

An osprey cam is being installed at Catawba Nuclear Station for the public to watch the osprey nesting.

“Duke Energy has an active and comprehensive Avian Protection Plan,” Auten said. “Take the osprey for example. Prior to 1984, no ospreys were known to be nesting on Lake Norman. Now there are 65 active Osprey nests on or surrounding the immediate area of Lake Norman.”

Between 1984 and 1987, in cooperation with the Carolinas Raptor Center, North Carolina State and Federal Agencies, Duke Energy helped relocate 12 young ospreys from Mattamuskeet National Wildlife Refuge and raise them on hacking platforms so that these birds would leave an imprint on the area and return after migration.

Osprey at Catawba Nuclear Station.

Osprey at Catawba Nuclear Station.

And at Catawba Nuclear Station, there is an active osprey nest on one of the communication towers on site. Duke Energy is in the process of putting a live-feed camera near the nest so the public can watch the Osprey online.

At Marshall Steam Station, Duke Energy and the local Wildlife Federation groups have put up nesting platforms for the great blue herons.

Not only does Duke Energy have an Avian Protection Plan, the company also has a Migratory Bird Hotline.

“Duke Energy’s Midwest, Carolinas West, Carolinas East and Florida have company hotlines to report all bird incidents that occur in or on the Duke Energy system ,” Auten said. “Duke Energy annually reports all avian incidents and nest removal and relocations to the local state and federal agencies and maintains avian permits for these incidents.”

_O4Q4520

A cormorant spotted on Lake Wylie near Catawba Nuclear Station.

Teacher Scholars Discuss the Nature of Energy

While teachers enjoy helping students learn about new subjects, teachers also enjoy learning and expanding their knowledge on subjects as well. In partnership with the Charlotte Teacher’s Institute(CTI) speaker series, the EnergyExplorium at McGuire Nuclear Station hosted an event for teachers to share what they learned from research projects related to energy. More than 70 people attended the event which provided an opportunity for  teachers to present their work focused on the theme: Teachers as Scholars: The Nature of Energy. Representing research conducted for elementary, middle, high school and university students, teacher also displayed their work and provided hands-on demonstrations to complement their research.

Discussion Topics and Presenters:

  • The Nature of Energy: How we use and Store it to Power Our Everyday Lives – Susan Trammell, Professor of Physics – UNC Charlotte
  • Energy in Our World – Cindy Woolery, Science Teacher – Elizabeth Traditional Elementary School
  • Crusing Continents and an Awesome Asthenosphere: Fueling Earth’s Ever Changing Surface – Julie Ruziska Tiddy – Science Teacher – Carmel Middle School
  • Mama did not Take the Kodachrome Away But Charge-Coupled Devices Did – Deb Semmler, Physics Teacher – East Mecklenburg High School

“Duke Energy is a strong supporter of CTI and we were honored to host the event at the EnergyExplorium,” says Christine Pulley, a member of the communications team at the EnergyExplorium. “As an energy education center we’re always looking for ways to educate the public on nuclear and other energy-related issues. We believe that when educators have an opportunity to expand their knowledge, it benefits their students and the overall classroom experience.”

The Charlotte Teachers Institute (CTI) is an initiative to strengthen teaching and learning in public schools. Led by classroom teachers in Charlotte-Mecklenburg Schools (Charlotte, N.C.) and professors at UNC Charlotte and Davidson College, CTI is founded on four pillars of strong professional development:  content knowledge, creativity, leadership and collaboration. In addition to hosting seminars for teachers, CTI hosts programs and special events to engage and educate teachers and the community at large.