Behind three separate rings of chain link fence topped with barbed wire lies a national conundrum with seemingly no end in sight. At Dominion Virginia Power's North Anna nuclear power plant, like similar plants across the country, nuclear reactions keep the turbines spinning and the related nuclear waste keeps piling up with no place to go.

When Energy Secretary Ernest Moniz announced March 24 that the U.S. Department of Energy would move ahead with a consent-based process to build one or more sites for interim storage of spent commercial nuclear fuel, he acknowledged that the only real solution is to create a permanent, underground geological repository.

The DOE was originally mandated by the Nuclear Waste Policy Act of 1982 to start taking possession of spent nuclear fuel in 1998, and it had plans to build a permanent storage facility at Yucca Mountain in Nevada. But political and local pressure forced the agency to stop developing that facility, leaving the nation's nuclear reactor operators with little choice but to continue storing the waste on-site.

At the same time, nuclear plant owners such as Dominion Resources Inc., whose Dominion Virginia Power's operations are known legally as Virginia Electric and Power Co., continued to pay into a DOE fund for the removal and permanent storage of their spent nuclear fuel. With DOE's failure to do so, the owners have repeatedly sued the federal government, and 72 related settlements have been signed to date requiring the government to pay the operators a combined $4 billion, Moniz said, noting that over the next 50 years the government's liability could amount to $23 billion unless a storage facility is developed.

Data provided by the Nuclear Energy Institute show utilities deposited $35.9 billion into the nuclear waste fund before a 2013 court decision ordered the DOE to suspend its collection of nuclear waste fees. Of that total, $10.8 billion has already been spent, according to an October 2014 report by the U.S. Government Accountability Office.

How much fuel is out there?

Most nuclear plants were never designed to store the spent fuel they created. Dominion was the first utility to remove fuel from a cooling pool and load it into a dry cask, said Everett Redmond, NEI's senior director of fuel cycle and technology policy. Other nuclear operators have since copied Dominion's method.

North Anna's two 979-MW reactors each hold 157 fuel assemblies, which amounts to 15 million pellets of uranium the size of the tip of a pinky finger bundled together in tubes, according to Dominion. When a nuclear plant undergoes a maintenance shutdown every 18 to 24 months, a third of the oldest fuel rods are removed and placed into wet storage. Each fuel assembly weighs 900 pounds and is kept under water as it is moved from the reactor to the storage pool. After at least five years of cooling, the rods are removed and placed in steel-lined dry casks and moved to a nearby concrete storage pad. Several levels of security surround that facility within the nuclear plant site.

Both Moniz and NEI estimate that about 2,000 metric tons of spent nuclear fuel is created every year, or about 71,780 metric tons of fuel over the past four decades. If that fuel were stacked end to end and side by side, it would cover a football field seven yards deep, the NEI said. For comparison, American Coal Ash Association data show that coal-burning factories and power generators produced 115 million tons of waste product in 2012.

At North Anna, about 60% of the fuel used in the reactor has been placed in dry casks. Dominion is planning to change its storage method for newly filled casks and build secure concrete racks to store the casks horizontally instead of vertically.

The Nuclear Regulatory Commission estimates that more than 100 spent fuel pools will reach capacity in 2015. While utilities have altered their pools to include secondary racks that still keep the fuel below 40 feet of water, as required, that is only a temporary solution.

Yucca is the only option

The Nuclear Waste Policy Act detailed the process to be used to select two long-term geological nuclear waste repositories, with many assuming that one was to be built in the East and the other in the West. The act also limited the first repository to a capacity of 70,000 metric tons until a second one could be built.

In addition, the act authorized the DOE to enter into contracts with utilities to remove fuel from reactor sites starting in 1998 and to collect a fee from those utilities. It gave states the right to override siting decisions for nuclear waste storage facilities unless Congress voted to overrule those decisions.

John Herrington, energy secretary from 1985 to 1989, originally recommended Yucca Mountain and two other sites, one in Texas and the other in Washington, for building permanent storage facilities. Much opposition followed, and as costs rose to test potential sites in different regions of the country, Congress in 1987 scrapped other plans and designated Yucca Mountain as the sole site to be considered for a repository.

"The decision was widely viewed as political and it provoked strong opposition in Nevada, where the 1987 legislation came to be known as the 'Screw Nevada' bill," the Blue Ribbon Commission on America's Nuclear Future wrote in its 2012 report to the energy secretary.

Partly because of the controversy, the DOE missed the 1998 deadline to begin accepting fuel but in 2002 determined that Yucca Mountain could be a suitable site. Nevada responded by issuing a notice of disapproval, which Congress overrode, clearing the way for the DOE to proceed with a license application.

The DOE took another six years to file that application due to litigation and safety concerns, but the Obama administration halted work on the facility in 2010. However, a federal appeals court in 2013 ordered the NRC to resume the licensing process.

The NRC completed the final two of five volumes of its safety review of Yucca Mountain in January, finding some issues with water rights but largely deeming the design safe. In addition, the NRC in August 2014 approved a new rule affirming the feasibility of long-term storage of spent fuel waste at nuclear plant sites.

As noted recently by Sen. Lamar Alexander, R-Tenn., and the NEI, the 70,000-metric-ton capacity planned for Yucca Mountain is not enough to contain the current amount of spent fuel already in existence, not to mention the new fuel that will be created by the time the facility opens. Moniz acknowledged this situation on March 24, but the Nuclear Waste Policy Act prohibits the development of any other nuclear waste repository besides Yucca.

Meanwhile, senators on both sides of the aisle have recently developed legislation taking aim at Yucca and finding a new place for spent nuclear fuel. Several members of the Nevada congressional delegation, including Senate Minority Leader Harry Reid, introduced a bill that would allow the construction of a nuclear waste repository only if state, local and affected Indian tribe officials give their consent. Reid, who announced March 27 that he would retire once his current term ends, is a longtime opponent of Yucca Mountain. In addition, a bipartisan coalition of senators on March 24 proposed to establish a new agency to manage the nuclear waste fund and build storage facilities.

Why move it at all?

Moniz was asked during his storage announcement why the fuel had to be moved from its current sites and whether the Blue Ribbon Commission had considered the safety of transporting the fuel.

"We need to move the fuel," Moniz answered, noting that the billions that will be spent on settlements could go "a long way to paying for a repository" and that a federal facility would have certain security advantages.

According to the GAO report, the DOE has identified rail as the desired method of transportation, but logistical challenges abound. For instance, not all nuclear facilities are near rail lines, and rail infrastructure was removed from some sites in the decommissioning of 12 reactors, meaning that the fuel will need to be moved using a combination of heavy-haul trucks, barges and rail. Moreover, railcars must be reinforced to safely transport the fuel, and the GAO said designing new railcars could take as long as nine years.

Moniz said funding has been allocated in the fiscal-year 2016 budget for site-specific assessments of transportation and fuel-handling infrastructure at shutdown reactor sites, preparations for railcars, transportation casks and other infrastructure.

Nuclear fuel has been, and continues to be, moved on the nation's rail system, but not on the scale that would occur if Yucca Mountain or a similar repository opened. The DOE has estimated that 175 rail and truck shipments would need to be made every year for 24 years to move 70,000 metric tons of spent fuel and other high-level nuclear waste to Yucca Mountain.

The NRC regulates the transportation of nuclear fuel, which will most likely be done using heavy-duty trucks on public highways and railways. The dry casks are inserted into shipping containers with 15-inch-thick walls designed to withstand severe accidents. During testing, the casks are dropped, punctured, set on fire and submerged under water to determine the cumulative effects on a given package, according to an NRC report on spent fuel transportation practices. The NRC believes there is a 1 in 1 billion chance that radioactive material would be released in an accident.

The nuclear industry, according to the NEI, has an "impeccable" safety record of transporting nuclear fuel over more than 35 years. When the 2011 earthquake in the Washington, D.C., metro area shook North Anna's full dry casks, the containers shifted slightly, but none were damaged. The plant tripped offline as expected in such a situation. Inside the plant's turbine building, a small crack developed on a small concrete pedestal, but it was the only damage Dominion found after inspecting the building. The quake brought national media to the plant and renewed fears about the continued storage of nuclear fuel and the safety of nuclear energy in the region as a whole.

Can the fuel be repurposed?

The recycling of nuclear fuel was halted by President Gerald Ford in 1976 and never resumed, even though the policy, extended indefinitely by President Jimmy Carter, was eventually reversed by President Ronald Reagan, according to the Blue Ribbon Commission's report. The commission said cost was a barrier to resuming attempts to recycle the fuel.

France, Japan, Russia and the United Kingdom are among the few nations that have a program to recycle spent nuclear fuel. The used pellets are put through a chemical process that recovers materials that can be turned into fresh fuel. It is then treated similarly to older fuel within the reactor and placed on the outer edges with the brand new fuel in the center. The process is expensive and creates a byproduct that has been a nonstarter for the U.S. since Carter put his foot down in 1977: Recycling nuclear fuel creates a small amount of plutonium, which can then be used in nuclear weapons.

Learning from other repository experiences

A geological repository exists in Carlsbad, N.M., called the Waste Isolation Pilot Plant, or WIPP, which at one time was planned to be the site of a nationwide storage facility for spent nuclear fuel but was restricted to defense-related waste only. The facility began accepting waste in 1999, 20 years later than intended. Shipments to the facility are on hold after an accident Feb. 14, 2014, that contaminated portions of the underground facility with radioactive materials.

The DOE released a report March 27 that said the accident resulted from a single drum containing an "incompatible" mix of radioactive waste and Swheat Scoop cat litter, causing gases to build up and eventually breach the container. During the incident, 21 workers were contaminated with low-level radioactivity. Moniz said the facility was a "priority" for the DOE, and the agency plans to resume shipments to WIPP in 2016, but full operations could still be several years away.

In addition to the new interim storage facilities for commercial spent fuel, Moniz announced that President Barack Obama had authorized the DOE to develop a permanent repository site for defense-related nuclear fuel storage. Moniz said the lessons learned in developing that site could be applied to the future development of a commercial fuel site.

"This process could play an important role in a broad nuclear waste strategy providing important experience in the design, siting, licensing and development of the facility that could be applied to the development of a future repository for commercial used fuel as well," Moniz said. "To be clear, the administration strongly supports moving forward on a parallel track to address storage and disposal of commercial used fuel."

Back to square one

But for Moniz, that approach does not appear to include Yucca Mountain, even though he believes the facility is still technically viable. Decades of delay and the "lack of a consent-based approach is pretty close to a fatal flaw in trying to site these facilities," he said.

"We're very clear, we don't think Yucca Mountain is workable for the reasons cited, but we are working now to develop again the baseline that we need for alternative geologies to move forward with a commercial repository."