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CRUD: Another Acronym Bites the Dust

Thomas Wellock
Historian

Chalk River Unidentified Deposits (CRUD). The nuclear industry loves its acronyms, and the myth behind CRUD—a term for corrosion particles that become radioactive—is almost as fabled as Safety Control Rod Axe Man (SCRAM). But in reality, crud, like scram, is not an acronym at all, but popular slang appropriated by Manhattan Project personnel.

The idea that crud was an acronym came from a 1959 article by Commander E.E. Kintner. In 1953, Kintner headed the Advanced Design Group under Hyman Rickover developing the Mark I prototype reactor for the first nuclear powered submarine, the Nautilus. To verify that the reactor’s fuel elements would not corrode, Kintner recalled, samples were placed in a research reactor located at Chalk River, Canada. After several months of irradiation, the fuel elements were covered in deposits—Chalk River Unidentified Deposits. This was worrisome since the deposits might block the flow of coolant around the fuel causing them to overheat and melt. While the problem was resolved by adjusting water chemistry, “CRUD” lived on as an acronym for radioactive deposits.

Crud was a term used early by the Hanford Engineering Works. Seen here is the site’s F Reactor complex under construction. Photo courtesy of the Department of Energy

Crud was a term used early by the Hanford Engineering Works. Seen here is the site’s F Reactor complex under construction. Photo courtesy of the Department of Energy

Kintner likely did not know that by 1953 the word crud had already been in use for nearly a decade at Atomic Energy Commission facilities. The word appeared in a technical manual as early as May 1944 at in the Hanford Engineering Works in Washington State. The manual described the use of chemical treatments “to seep insoluble ‘crud’ and mud from the solution.” By 1947, “crud” was a common enough in the AEC that reports from Hanford and Oak Ridge no longer used quotation marks to describe the “crud deposition problem.”

Thus, CRUD is really an example of a backronym — where words are identified to fit the letters of an existing word.

So, why was “crud” used to describe radioactive deposits in the first place? Crud was a common word well before World War II that likely derives from the Welsh cryd, meaning disease or plague. By the early 1930s, crud became slang for unpalatable food, filth, a sloppily dressed man or an illness, as in, “I’ve got the crud.” By World War II, soldiers called any unknown illness “the crud,” and a comic book of the era featured a Corporal Crud as one of its characters.

It seems likely that the negative connotations of crud made it a fitting descriptor for contamination associated with radioactive deposits. The etymology of scram and crud, then, reveals how Manhattan Project workers tried to make sense of the uncommon new world of the atom through common language.

Listen In On Our Watts Bar Unit 2 Meeting with TVA

Jeanne Dion
Project Manager
Office of Nuclear Reactor Regulation

 
The NRC’s been closely observing the Tennessee Valley Authority’s work in completing Unit 2 at the wattsbarWatts Bar Nuclear Plant near Spring City, Tenn. Our meeting tonight will discuss where TVA stands in its effort to get an operating license for Unit 2.

If you can’t make it in person, we’re offering a teleconference and Web-based access to the meeting presentation. You can get the phone and webinar details from me or my NRC co-worker Christopher Even. For those who can attend, we’ll be available to answer questions and discuss issues with local residents and interested members of the public.  

During the meeting we’ll lay out the inspections and licensing activities the NRC must complete before we could decide whether Watts Bar 2 qualifies for an operating license. Some of our senior managers will explain how we’ve reached this point and what we need to see before we could conclude that the plant is safe to operate.

While we’re still reviewing a few issues, all the information we’ve seen so far indicates TVA is on track to meet the safety and security requirements for a reactor operating license.

If we issue Watts Bar Unit 2 an operating license, TVA would still have to load fuel and begin a series of tests during plant startup and a gradual increase in power output. The NRC would continue inspecting and overseeing the completion of these startup activities prior to Unit 2 generating full power and starting commercial operation. If licensed, Unit 2 would be the first plant to begin commercially operating in the U.S. since Watts Bar Unit 1 started in 1996. For more information please visit the NRC public webpage on Watts Bar Unit 2.

Western U.S. Reactors are Completing Their Seismic Picture

Lauren Gibson
Project Manager
Japan Lessons-Learned Division

An ongoing lesson from 2011’s Fukushima Dai-ichi accident involves U.S. reactors better understanding their earthquake hazard. Reactor owners in the Western parts of the country have had to assemble a particularly complex jigsaw puzzle of seismic information. They’ve just sent the NRC their detailed re-analysis.

seismicgraphicThe graphic shows the three pieces of information U.S. reactor owners have used to analyze their specific hazard:

  • Where quakes are generated (seismic source)
  • How the country’s overall geology transmits quake energy, (ground motion/attenuation) and
  • How an individual site’s geology can affect quake energy before it hits the reactor building (site amplification).

Central and Eastern U.S. reactors benefitted from region-wide updated earthquake source information and a model of quake energy transmission for the first two pieces. Plants west of the Rockies, however, had to deal with the West’s more active and interconnected faults.

Columbia, Diablo Canyon Part I and Part II and Palo Verde used the Senior Seismic Hazard Analysis Committee (SSHAC) approach to develop site-specific source models and ground-motion models. This group of independent seismic experts develops guidance on major seismic studies such as this. The group has met several times the past few years to ensure the Western plants properly conduct and document their seismic activities.

The NRC carefully considers SSHAC comments and recommendations before the agency comes to its own conclusions on seismic issues. We’re currently evaluating the Western plants’ reports and will issue our short-term screening and prioritization review later this spring.

As for the Central and Eastern U.S. plants’ March 2014 submittals, we screened them to determine what other actions the plants might have to take. Plants that have more to do were grouped into three priority groups with staggered deadlines. Many of those plants submitted additional analyses in December 2014, and the NRC continues reviewing both that information and the March 2014 submittals.

Photo Friday — The NRC Operations Center

fotofridayopcenterVisitors got a rare glimpse of the NRC’s Operation Center last week when tours were offered as part of the annual Regulatory Information Conference. Here, NRC officials show off the Executive Team room, from where an NRC response effort would be managed. Other sections of the center include the Reactor Safety team, the Protective Measures team, the Liaison team and the Public Affairs team, among others. The Op Center is staffed 24/7 by specially trained Headquarters Operations Officers.

Continuing to Learn the Lessons of San Onofre

Rebecca Sigmon
Reactor Systems Engineer
Office of Nuclear Reactor Regulation

Almost two years after the San Onofre nuclear power plant shut down permanently, the NRC has kept an eye on what we can learn from the events that led to the plant’s closure. The latest product of this work reviews the agency’s procedures related to Southern California Edison’s (SCE) installation of new steam generators at the plant.

songsThis work builds on our response to the steam generator damage San Onofre discovered in January 2012. At the time, our inspections and reviews aimed to understand what had happened and ensure public safety would be maintained before the plant could restart. Even after SCE decided in June 2013 to shut San Onofre down, the NRC continued its reviews to try to prevent something similar from happening at other reactors.

A year ago, our Executive Director for Operations asked the offices of Nuclear Reactor Regulation and New Reactors, as well as our Region IV office, to review the NRC’s own actions. The effort focused on the event and the NRC’s response to find any areas for improving our processes. The review covers issues raised in a 2014 NRC Inspector General report.

The review examines eight basic topics and discusses 17 actions to enhance what are already effective tools for overseeing U.S. operating reactors. Some of the topics include: better identification of potential design issues before they lead to problems; better assurance that plants comply with our requirements in 10 CFR 50.59, “Changes, Tests, and Experiments;” and improving communications with the public.

The review touched on all aspects of the NRC’s involvement in the San Onofre event, from on-site inspection to Congressional briefings, from technical review to website maintenance. The review team discussed some of these issues with industry experts. The team also sought comments from members of the public who participated in meetings about the San Onofre event and subsequent technical analyses.

The review concludes, among other things, that the 50.59 process is appropriate for plant activities that replace large components, such as steam generators. The review also finds that the staff properly used a Confirmatory Action Letter as an oversight tool in responding to the San Onofre events.

The staff’s already working on many of the review’s 17 actions. For instance, the staff is working on documents that clarify several areas of NRC guidance on following the 50.59 process. The NRC is also working on additional training for agency staff to improve their 50.59 reviews and associated activities. All of this ongoing work will help ensure U.S. nuclear power plants continue to safely operate, maintain and repair their systems.

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