Tuesday, January 24, 2017

Why Buy A Shutdown Nuclear Plant? The Answer Might Surprise You

Today, the Nuclear Regulatory Commission (NRC) held a public meeting to consider the latest development in what has become a growing trend in the nuclear power industry – accelerating decommissioning by transferring licenses to third parties after a plant shuts down. The topic of today’s NRC meeting was to provide an overview of Entergy’s plan to sell and transfer the NRC licenses for the Vermont Yankee Nuclear Power Station – which permanently ceased operations at the end of 2014 – to NorthStar Group Services, Inc., a company that specializes in nuclear decommissioning and environmental remediation. This meeting began the process by which the companies seek NRC approval of the transaction.

Vermont Yankee Nuclear Power Station
Why would anyone want to buy a nuclear plant? Because they can decommission it faster, with more certainty in schedule and costs,that’s why. In the nuclear decommissioning business, time is literally money. NRC regulations allow up to 60 years for completion of decommissioning, and waiting is a prudent and safe practice that often becomes necessary when plants shut down early. Plant owners are required to set aside money in a nuclear decommissioning trust fund while the plant is operating and to assure the NRC that this fund will be sufficient to decommission the plant. For early shutdowns like Vermont Yankee, additional time may be needed for the decommissioning trust fund to grow through the accumulation of investment interest before the more significant work can begin. What decommissioning companies are saying, though, is that their experience enables them to provide more certainty to efficiently and safely dismantle the plants without having to wait.

It is not surprising that much has been learned about nuclear plant decommissioning. The process has already been completed at 11 U.S. power reactors and dozens of additional facilities around the world, where radioactive systems and structures have been decontaminated and dismantled, with any remaining low-level radioactive waste shipped off to disposal sites. High-level radioactive waste, in the form of used nuclear fuel, is transferred to robust concrete and steel dry cask storage systems that are typically located at the site until a permanent disposal facility is developed by the U.S. Department of Energy.

Existing Vermont Yankee ISFSI pad and the cleared site for the second ISFSI
Recently, this experience was put to the test at the Zion Nuclear Power Station in Illinois. Shut down in 1998, Zion was in a holding pattern until 2010, when Exelon transferred the license to a subsidiary of decommissioning company Energy Solutions (now known as Zion Solutions). The project is now on track for completion well ahead of its 2020 deadline – more than a dozen years earlier than originally planned. A similar approach is now also being applied to the decommissioning of a reactor in LaCrosse, Wisconsin which ceased operations in 1987.

Although every plant is different, the Vermont Yankee, Zion and LaCrosse transactions have much in common when it comes to creating win-win business propositions. And the real winners in these transactions are the people who live around the plant. Under the agreement discussed today, Vermont Yankee decommissioning and site restoration will be scheduled for completion decades earlier, with cost certainty and additional financial assurances. This arrangement also will begin generating economic activity at the site during the active decommissioning phase many years sooner than originally planned, with benefits for the local and regional economy. 

While improved business models are making a huge difference, there are two additional obstacles that, if overcome, would further improve the process: 1) regulatory uncertainties that exist during the transition from operations to decommissioning (Vermont Yankee is past that phase) and, 2) the shipment of used fuel off the site to a federal facility (as required by law) so all land associated with the plant can be released. On the first issue, in November 2015, the NRC proposed a rulemaking that has the potential to make the transition more efficient. And regarding for the used fuel, just last week former Texas Governor Rick Perry, who has been nominated to be Secretary of Energy, promised in his confirmation hearing that, "The time of kicking the can down the road — those days are over.”   

The above is a guest post from Rod McCullum, senior director of fuel and decommissioning at NEI.

Wednesday, January 18, 2017

How Nanomaterials Can Make Nuclear Reactors Safer and More Efficient

The following is a guest post from Matt Wald, senior communications advisor at NEI. Follow Matt on Twitter at @MattLWald.

From the batteries in our cell phones to the clothes on our backs, "nanomaterials" that are designed molecule by molecule are working their way into our economy and our lives. Now there’s some promising work on new materials for nuclear reactors.

Reactors are a tough environment. The sub atomic particles that sustain the chain reaction, neutrons, are great for splitting additional uranium atoms, but not all of them hit a uranium atom; some of them end up in various metal components of the reactor. The metal is usually a crystalline structure, meaning it is as orderly as a ladder or a sheet of graph paper, but the neutrons rearrange the atoms, leaving some infinitesimal voids in the structure and some areas of extra density. The components literally grow, getting longer and thicker. The phenomenon is well understood and designers compensate for it with a variety of techniques. One simple one is replacing some metal parts every few years.

But materials scientists at the Nebraska Center for Energy Sciences Research, at the University of Nebraska in Lincoln, are working on a variety of “radiation-tolerant” materials that are self-healing. These would improve the durability of the metal parts, which would be helpful for the current fleet and more important for advanced reactors still in the design phase. Fuel elements in existing reactors are replaced after a few years, but some of the new designs would leave metal parts in place for far longer. And better materials can improve the reliability of any industry.

The researchers are working with the fact that a different class of materials, called “amorphous materials,” do not suffer damage when bombarded with neutrons. Amorphous materials, which are already in common use, do not suffer the same kind of damage. The atoms in an amorphous material are not arranged in a repeated pattern. Polymers and gels are two kinds of amorphous solids.

What the Nebraska researchers have discovered, in work partly funded by the Nebraska Public Power District and the Department of Energy's office of Nuclear Energy, is that if crystalline materials are sandwiched with amorphous materials, the flaws in the crystalline materials --- both the voids and the areas with extra density --- migrate toward the border of the two. And when they meet, they annihilate each other.

The researchers use a particle accelerator rather than a reactor, to create the damage, and then study it with powerful microscopes. They work with layers a few microns thick.

Bai Cui, an assistant professor of mechanical and materials engineering, said that at the boundary, the two flaws neutralize each other quickly. The atoms are vibrating at a rate of about 130 trillion times per second (ten to the 13th), and the flaws locate each other in about 100 cycles – that is, on the order of a trillionth of a second.

Jian Wang, an associate professor at the center, pointed out that some advanced reactor designs would have operating temperatures of over 200 degrees C and would use corrosive coolants, like molten salt or supercritical water, and are intended to run for 80 years or more. Micro-layers of amorphous materials could work well in that environment, he said.
The center is also working on nano-materials that can be mixed into steel to attract and neutralize flaws. The material can be used in a weld, and is then mixed in using “laser peening.” Generally, peening means shooting particles at a target at high velocity, often to strip off the top layer of the target. But in laser peening, the pressure of light distributes the nano-materials within the steel.

The center is directed by Dr. Michael Nastasi, a research scientist formerly at the Energy Department’s Los Alamos National Laboratory. The cutting-edge nuclear research here is not its only focus; this being Nebraska, it also conducts research on wind turbines, biofuels, crop irrigation and other areas.

Friday, January 13, 2017

The Next Big Thing in Nuclear Power: Think Smaller & Safer

Dr. Everett Redmond
The following is a guest post by Dr. Everett Redmond, NEI's Senior Director, Policy Development.

There’s a lot to like about the small modular reactor design that NuScale Power submitted yesterday to the Nuclear Regulatory Commission. Most often people talk about the ability to build such reactors in a factory and ship them by truck or rail, in nearly-finished form, to where they are needed, and to add generating capacity to a plant in modest increments, as demand grows. But it’s easy to overlook another strength of the NuScale design: one of its intrinsic features is a simple way to enhance the safety of the reactor fuel.

There’s a fancy name for this feature: a high surface-to-volume ratio. In plain English, as a container gets smaller, its surface area gets larger relative to its volume, a phenomenon obvious to anyone who cooks. Take a hardboiled egg out of the pot of boiling water and put it into a bowl of cold water, and the egg cools very quickly. It does that because the water draws away the heat much faster than air could, and the area of the egg shell is relatively large compared to volume of the egg. Contrast this with a boiled potato that would take longer to cool because its surface area is smaller in comparison to its volume.
Cooling the NuScale SMR is like chilling a hard boiled egg.*
The NuScale module’s core is about one-twentieth the size of a standard large unit. The NuScale cores each sit in their own containment, a vessel a little like a thermos bottle. The containments are submerged in a huge pool of water. Like a thermos, the NuScale design uses a vacuum between the inner wall and the outer wall of its containment vessel, so the reactor can produce steam without heating up the surrounding water.

If there’s a problem, valves will break the vacuum and the steam from the reactor will flow into that vacuum space, and condense into water. So that space, which used to be a vacuum, and insulating layer, will become filled with water which will conduct heat away from the core. The heat will naturally travel through that water and to the outer wall of the module, and from there into the pool. The heat will bleed away fast enough so that the core can’t heat up to the point of damaging the fuel.

That principle leads to other advantages. The design is intended to be “walk-away safe,” with no short-term actions required by the operators. And existing reactors keep safety-grade backup diesel generators on site, but NuScale does not need these, because it doesn’t need the electricity to pump water or run mechanical systems to draw away heat. In fact this simple design does not use pumps when running normally to move the useful heat out of the core so it can be turned into electricity; that happens through natural convection.

Of course, an inherently safe design is always a good idea. But there’s another advantage here. The NRC has yet to evaluate NuScale’s application, but NuScale’s engineering shows that the emergency planning zone for its plant should extend only as far as the plant fence. The reactor can be located close to where electricity is needed the most.

That will make the NuScale reactor a good candidate for replacement power at old fossil-fueled sites in the United States, and in fast-growing cities around the world that do not have adequate electric local generation or a strong power grid to carry in power from distant places.

*Photo by Andrea Nguyen, provided under a Creative Commons license.

Thursday, January 12, 2017

What the Millstone Nuclear Power Plant Means to Connecticut & New England

The following is a guest post by Matt Crozat, Senior Director, Business Policy at NEI.

Matt Crozat
Occupying less than a square mile along the busy Northeast Corridor between New York and Boston, it’s easy to miss the Millstone Power Station. A new economic impact study released today by NEI documents just how important the two-unit Dominion plant is to Connecticut and the region. Indeed, if Millstone were lost it would be dearly missed.

Millstone, owned and operated by Dominion Resources, provides almost 60 percent of the electricity consumed in Connecticut, and adds nothing to the region’s air pollution. In fact, it displaces fossil-fired plants, which would pollute.

But its role is felt even more deeply when one considers the economic value the plant generates. There are 1,569 full-time employees at the plant, in Waterford, but the economic activity they create supports an additional 1,691 jobs in the state and beyond.

But Millstone’s main role isn’t to provide employment, it is to produce electricity. The Millstone Power Station generates over 17 billion kilowatt-hours of electricity annually which is enough to supply 2 million homes. This generation provides economic benefits to everyone in New England by keeping electricity prices low. Money that families aren’t spending on their power bill can be used for other goods and services that families need, and their spending helps the economy. This report estimates that Millstone provides an additional $1.6 billion in economic activity from lower electricity prices in Connecticut and New England which leads to almost 9,000 jobs across the region.

Each of the nuclear plants in the U.S. has significant economic impacts in their communities. NEI has produced economic benefits reports for Ohio, Illinois and Texas, to name a few. A longer list can be found here.