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REFRESH: On the Wild Side at U.S. Nuclear Power Plants

Update: At nuclear power plants in the southwest, snakes, scorpions and black widow spiders are not an unusual sight. Resident Inspectors have to be especially careful during their walkthroughs in those plants not to poke into areas between pipes or bundles of electrical cables where venomous critters may be nesting.  But the most exotic wildlife may be the denizens at the South Texas Project nuclear plant in Bay City, where alligators abound. “We usually have about 75 alligators roaming around on site here at any given time,” said Shelia Davis, a corporate communications specialist for the South Texas Project. “If they stray into areas where they shouldn’t be we have people who are specially trained and can move them safely to our 7,000 acre reservoir.” Victor Dricks

Neil Sheehan
Public Affairs Officer
Region I

refresh leafExamples abound of the ways in which nature abhors a vacuum. Raptors will set up shop on a skyscraper ledge, just as they will on a cliff, if it suits their needs. Coyotes have been increasingly spotted in urban settings, even roaming about the streets of Manhattan. Last year, surveillance cameras captured images of a mountain lion strolling the Hollywood Hills after dark.

Nuclear power plants are also home to a variety of wildlife. Despite the industrial nature of these facilities, they are usually situated on large tracts of land encompassing hundreds of acres. They are also adjacent to bodies of water in order to tap into that H20 for cooling purposes.

All of that property and access to water can entice a variety of animals and birds to take up residence on the sites. And they do just that.

Information supporting this can be found in the Post-Shutdown Decommissioning Activities Reports for U.S. nuclear power plants that have ceased operations.

In the report for the Vermont Yankee nuclear power plant, which was submitted to the NRC in December 2014, it’s noted that the main emissions stack includes an attached nesting box for peregrine falcons. The box was installed by the company in 2009 at the request of the Audubon Society.

It’s been a rousing success, as according to the report “there have been two consecutive years of four young born and successfully fledged since 2012.”

An alligator crossing sign at the South Texas Project nuclear power plant.

An alligator crossing sign at the South Texas Project nuclear power plant.

Current decommissioning plans call for the Vernon, Vt., plant to be placed in storage for several decades prior to the initiation of major dismantlement work. However, when the time comes to remove the stack, the plant’s owner will need to consult with the U.S. Fish and Wildlife Service prior to removing the nesting box since the peregrine falcon is protected under the Migratory Bird Treaty Act.

Peregrine falcons can also be found at the Three Mile Island nuclear power plant, in central Pennsylvania. The PSDAR for TMI-2, where a severe accident occurred in 1979 and which won’t be taken apart until the neighboring TMI-1 permanently shuts down and is also ready for that work, shows peregrine falcons have nested on the TMI reactor building since 2002.

Meanwhile, the plant’s meteorological tower, which collects important weather data, has been home to an osprey nest every year since 2004. Ospreys, also referred to as fish hawks (with a wing span from around 5 feet), like to be around water, so it’s not surprising that TMI, situated on the Susquehanna River, is a place they call home.

A variety of wildlife can be found in the vicinity of the Crystal River 3 nuclear power plant, located on the Gulf Coast of Florida. That plant’s PSDAR, which the NRC received in December 2013, identifies the following threatened or endangered species in the vicinity of the site: Two species of fish — Gulf sturgeon and smalltooth sawfish; five species of sea turtles — green turtle, hawksbill, Kemp’s ridley, leatherback and loggerhead; one crocodilian species — American alligator; and one marine mammal — Florida manatee.

But on the site itself, only one state-listed threatened species, the bald eagle, and one state-listed endangered species, the wood stork, are found, according to the report. The PSDAR adds that three other species can “potentially occur” on the property: the gopher tortoise, the eastern indigo snake and the piping plover.

In the case of all of these plants and the others around the country, precautions must be taken to minimize the impacts of operations and decommissioning activities on these species and their habitats, consistent with federal and state laws.

REFRESH is an occasional series where we rerun and/or update previous blog posts. This post first ran in August 2015.

Throwback Thursday – The Lab Van ‘70s Style

TBT-2_blog sizeaugustGerald R. Ford was president. Median household income was $11,800. Gas cost 57 cents a gallon. And NRC inspectors, as part of the Independent Measurements Program, routinely hit the road in a fully equipped van containing a mobile laboratory. Inspectors measured samples of radioactive effluents from nuclear power plants, checking on the accuracy of sampling routinely done by the plants’ own laboratories.

The image directly above on the left shows an NRC inspector placing a liquid radioactive waste sample in a cryogenic detector for analysis of its isotopic composition. In the image directly above on the right, an NRC inspector reviews analytical data. A similar van, but with portable equipment, was used to verify measurements during safeguards inspections of materials facilities. During a safeguards inspection, the equipment was removed from the van and carried inside the facility for use.

Images from the 1975 U.S. Nuclear Regulatory Commission Annual Report

Ten Things You May Not Know — About Nuclear Power and the NRC

Stephanie West
Public Affairs Specialist

It’s summer and you might be reading this blog while relaxing in the sun or otherwise taking it easy. So, just for fun, we’ve listed 10 nuclear-related facts you might find interesting, albeit light, reading:

1. Nothing lasts forever. Every year or two, reactor operators spend about a month, removing and replacing about one-third of a reactor’s fuel and performing various maintenance activities during plant outages to make sure reactors perform efficiently. Source: NRC Information Digest

youtube22. No bowling leagues. In order to preserve their objectivity, NRC resident inspectors are discouraged from attending social events where nuclear plant employees are involved. They also may not serve at any nuclear plant longer than seven years.

3. Who at the NRC must train to escape a sinking helicopter? Health physicists in NRC’s Region IV office of course. A handful of them must fly to inspect offshore oil rigs in federal waters. They must be prepared not only to escape a helicopter, but to survive a fire on an oil platform by jumping into the sea and fighting off sharks by kicking them in the snout.

4. Quick question: Where is the largest research reactor in the U.S.? Check below for the answer. But you should know that Research and Test Reactors operating at levels of 2 megawatts thermal (MWt) or greater receive a full NRC inspection every year. The largest U.S. research reactor, which produces 20 MWt, is 75 times smaller than the smallest U.S. commercial power reactor.

5. Once the explosive ingredient in Soviet nuclear warheads, highly enriched uranium was diluted to become the stuff that powered our homes and businesses in the U.S. The Megatons to Megawatts program was born from a 1993 agreement between the U.S. and Russia to reduce the stockpile of Soviet-era highly enriched uranium.

6. Everyone loves this story. MB900371234The most all-time viewed post on this NRC blog is “Putting the Axe to the Scram Myth” with more than 18,000 views since it was originally posted in 2011.

7. It’s just not easy being a spent nuclear fuel transportation cask. Each must be designed to survive a 30-foot drop onto an unyielding surface, a puncture test, a fully engulfing fire at 1,425 degrees Fahrenheit for 30 minutes and immersion under water.

8. The Watts Bar nuclear plant makes its mark both on this century and the last. Unit 1 was the last U.S. reactor to come online in the 20th century and Unit 2 is expected to be the first to come online in the 21st. Read more about the history of the Watts Bar Nuclear Plant in our blog post: Watts Bar – Making History In Yet Another Century.

9. Months of planning, thorough inspections, dozens of law enforcement officials, a specially equipped truck – and a S.W.A.T. team. It sounds like a checklist for an action movie. Instead it was used to move a mini refrigerator-sized irradiator in Anchorage about 2.5 miles. These small irradiators are used to sterilize medical equipment and products, and contain a sealed source of radioactive material. They are protected to keep the public and environment safe from exposure, but also to keep it out of the hands of terrorists.

reportcard10. It’s no “easy A.” In addition to years of related experience, NRC-licensed nuclear plant operators must receive extensive classroom, simulator and on-the-job training. But they also must be certified as physically and mentally fit to be an operator. Source: NRC Information Digest

Answer: National Institute of Standards & Technology, Gaithersburg, Md.

 

Dry Casks 101: What Do Robots Have to do With Dry Cask Storage?

Darrell Dunn
Materials Engineer

CASK_101finalCutting-edge robot technology is making it easier to inspect inside spent fuel dry cask storage systems.

You may remember from past blog posts that most spent fuel dry cask storage systems, or casks, consist of stainless steel canisters that are welded shut to safely contain the radioactive contents. The canisters are in turn placed inside thick storage overpacks to shield plant workers and the public from radiation. As these casks remain in use for longer time frames, the ability to inspect canister surfaces and welds will become an important aspect of the NRC’s confidence in their safety.

To be clear: techniques for inspecting canister surfaces and welds have been used for decades. These techniques are collectively known as nondestructive examination (NDE) and include a variety of methods, such as visual, ultrasonic, eddy current and guided wave examinations.

img2 (002)Where do robots come in? They are a delivery system. Robots are being developed to apply these NDE techniques inside casks. Not just any robot will do. These robots need to fit into small spaces and withstand the heat and radiation inside the cask. The state-of-the-art is evolving quickly.

To date, the Electric Power Research Institute and cask manufacturers have successfully demonstrated robotic inspection techniques to NRC staff three times: at the Palo Verde plant in Arizona (Sept. 2-3, 2015), at the McGuire plant in North Carolina (May 16-19, 2016), and just last month, at Maine Yankee (July 12-13, 2016).

At Palo Verde, the robot was used to deliver eddy current testing instrumentation inside a cask. Eddy current testing detects variations in electromagnetically induced currents in metals. Because it is sensitive to surface defects, eddy current testing is a preferred method for detecting cracks. The inspection robot was used to examine part of the mockup canister fabrication weld. An EPRI report provides a detailed description of the Palo Verde test. Future reports are expected on the McGuire and Maine Yankee demonstrations. These demonstrations are helping to refine the robots’ designs.

Cutaway Cask Mockup with Robot (002)The Maine Yankee demo was conducted in July 2016 on a cask loaded in 2002. The demo involved a robot maneuvering a camera with a fiber optic probe, which meets the industry code for visual examinations, inside the cask. The probe was able to access the entire height of the canister, allowing the camera to capture images of the fabrication and closure welds. The welds showed no signs of degradation. The canister was intact and in good condition.

The robot was also able to obtain samples from surfaces of the cask and canister. These samples are being analyzed for atmospheric deposits that could cause corrosion.

Ultimately, if degradation is identified, cask users would select their preferred mitigation and repair option.  They would have to meet the NRC’s safety requirements before implementing it.

Cask inspections are important to ensure continued safe storage of spent nuclear fuel and robots will continue to be a helpful tool in this important activity.

When Plans Change — Discontinuing Some Rulemaking

Leslie Terry
Team Leader
Office of Administration

NRC does its job with regulations contained in the Chapter I of Title 10 of the Code of Federal Regulations. These regulations cover everything from commercial 10cfrreactors to nuclear materials used in a variety of settings, to storing and disposing of nuclear waste.

A year ago we explained how we keep our rules up to date and unveiled a web page to provide periodic updates on our rulemaking activities. To recap, we identify the rules already under development and any new rules that need to be written. We then rank by priority every rule, regardless of the regulatory area. This way we ensure we’re focusing our resources on the high priority rules that most contribute to the NRC’s key strategic goals of safety and security. We also monitor the progress of our rulemaking activities and develop budget estimates for preparing new rules.

Sometimes our rulemaking plans change. Our Commissioners voted recently to approve a staff recommendation to discontinue eight rulemaking activities that were in the early stages of development.

During our most recent review, the staff identified several rulemakings that were in the early stages of development, but staff believes are no longer needed to meet the NRC’s key strategic goals of safety and security. The staff wrote a paper requesting Commission approval to discontinue nine activities, and discussed a 10th rulemaking the Commission had already decided to discontinue. The Commission agreed to discontinue seven of the nine rulemakings the staff proposed.

The discontinued rulemakings covered a variety of topics, and the basis to discontinue is different for each rulemaking. For example, we have a rulemaking underway to better define the requirements for reactors that have permanently shut down and are decommissioning. We felt that rulemaking was an appropriate place to address decommissioning options, including entombment for power reactors, so we are discontinuing a separate rulemaking on entombment.

We also feel the current case-by-case framework is sufficient for reviewing the limited number of requests we’ve received for alternate disposal pathways for waste with very low activity. So we’re discontinuing a rulemaking to set generic requirements, which had already been on hold for a number of years. Instead, we’ll take another look at the issue as part of an assessment of low level radioactive waste disposal, and if we decide that a rulemaking is necessary, we’ll ask the Commission to revisit the issue.

We encourage you to read more about the Commission’s vote and the staff’s proposal on our web site. You can also check our prioritization web page for future updates on our rulemaking activities.

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