Monday, May 24, 2021

Green Energy: Take A Fresh Look At Nuclear

Plans to expand nuclear power usually trigger fears of Chernobyl, Fukushima and Three Mile Island. Nightmarish accidents occurred at those three nuclear plants, designed in the 1960's and built in the 1970's, fueling a public climate of jitters about the safety of this energy source.

However, misgivings about nuclear's safety are at odds with the facts. At the end of 2019, there were 98 operating nuclear reactors at 58 power plants in 29 states in the U.S. with no incidents since the Three Mile Island radiation leak of 1979.  That was more than two decades ago. That plant is 38-years-old.

Primarily due to the escalating costs of regulation, construction and maintenance, the total number of operational nuclear reactors has shrunk from its pinnacle of 108 in 2000.  The price tag for today's traditional nuclear power plant, depending on capacity, runs anywhere from $6 billion to $9 billion.  

Although the country has fewer nuclear reactors, those power plants still produce 20% of all electricity. Natural gas accounts for 38% of power generation; coal, 23%; hydroelectric, 7%, and wind and solar output equals 12%.  Those sources combined churned out 4.1 billion mega-watt hours of power.  

Those figures are from the U.S. Energy Information Administration (EIA), which published the data this year. According to an EIA report, the U.S. has the most nuclear generation capacity of any nation, but France's nuclear plants account for a larger share of the country's total electricity output, 71.5%.   

As the world searches for ways to reduce carbon emissions, there is increasing interest in small modular nuclear reactors (SMR).  These advanced reactors are envisioned as power sources for electricity, desalination and other industrial uses.  U.S., Canada and China are pursuing the technology.

In 2020, the Energy Department awarded $210 million to ten projects to develop technologies for SMR's as part of an Advanced Reactor Demonstration Program.  Scores of SMR initiatives are underway at private firms, including General Electric, a pioneer in nuclear power.  

Although still in the development stage, these small, modular reactors will prospectively be designed to develop 300 mega watts of power, compared with more than 1,000 megawatts for larger plants operating in the country.  

What makes these smaller reactors different? The footprint is reduced.  In fact, one SMR could fit into an area the size of a microbrewery.  The light water-cooled reactors are modular, which means the plants could be built faster and cheaper, saving billions of dollars. 

These innovative reactors could be shipped by rail to power sites, reducing the time to erect a new plant and making nuclear more cost effective.  A few nascent SMR designs are contemplating incorporating the use of a coolant other than light water, such as gas, liquid metal or even molten salt.   

Proponents are not calling for abandoning green energy sources such as wind and solar, but suggest these innovative reactors could replace larger, outdated nuclear or coal facilities. They insist the mini-reactors are inherently safer than the older designs, offering added protection from nuclear meltdowns. 

The ingenious nuclear plant would work the same as today power facilities, heating water to produce steam.  The steam is used to spin large turbines that generate the electricity.  The process requires fission to split atoms inside the reactor.  The reactor core contains uranium fuel. 

In September, the Nuclear Regulatory Commission issued a safety evaluation report on an SMR, a critical step before the final design can be approved.  The firm,  NuScale, based in Portland, is developing the first commercial SMR for utilities in Utah, slated for launch by the end of the decade.

One drawback for nuclear energy has always been the issue of nuclear waste, which remains highly radioactive for longer than a human lifespan. The new downsized reactors will produce waste, but there will be less of it because of its diminished power capacity. 

Concerns about nuclear waste are legitimate, but often exaggerated by the media.  All the waste from 60 years of America's nuclear reactors would take up less space than one average-size Walmart store. Compare that to the toxic waste from a single, large coal plant. It dwarfs nuclear waste.

Nuclear emits no carbon.  It can supplement renewables.  When clouds blot out the sun or the winds are calm, those two sources of energy are dormant.  Without a reliable backup source, homes and businesses would be plunged into darkness.  Today coal plants often are the backup.

As a practical matter, the more solar and wind populate a country's energy grid, the more backup power is needed.  Take Denmark for example.  On windy days, the country's offshore wind farms supply 100% of its power.  Over a full year, wind output accounts for only 50% of electricity generation.

On windless days, Denmark purchases backup power from other countries at premium prices. 

Germany has plowed $400 billion into its renewable program, yet carbon emissions have remained stubbornly high.  The reason? Backup power is often supplied by coal or gas burning plants. Closer to home, California has made billions in investments in renewables, but emissions remain essentially flat. 

A recent report by the National Renewable Energy Lab, an advocate for green energy, issued a green energy projection it cautiously labels as "theoretically" possible:

"Renewable electricity generation from technologies that are commercially available today, in combination with a more flexible electric system, is more than adequate to supply 80% of total U.S. electricity generation in  2050."  Even under this optimistic scenario, there's a 20% power shortage.

This by no means diminishes renewables.  Wind and solar are excellent sources of clean, carbon-free power.  However, addressing the power-gap should be the top concern of any country or environmentalist interested in achieving a carbon neutral goal. Ignoring it is foolhardy. 

There is no technology on the horizon that offers the scale of nuclear power as an immediate backup. Hydrogen and batteries are often discussed as green alternatives, but any development of a working plant remains decades away, if ever.

Solar panels and wind farms may offer the best hope of reducing carbon emissions, but neither can overcome intermittency when nature interrupts their source for generating power.  Future electric grids will need clean backup power.  That's why it's urgent to take a fresh look at nuclear.

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