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Category Archives: Nuclear Materials

NRC’s Materials and Waste Management Programs Coming Back Under One Roof

Chris Miller
Merge Coordinator and Director of Intergovernmental Liaison and Rulemaking

 

When Congress created the NRC in 1974, it established three specific offices within the agency. One of them was the Office of Nuclear Material Safety and Safeguards, or “NMSS” in NRC shorthand. This office was charged with regulating nuclear materials and the facilities associated with processing, transporting and handling them.

fuelcyclediagramThis charge was, and is, broad. The NRC’s materials and waste management programs cover facilities that use radioisotopes to diagnose and treat illnesses; devices such as radiography cameras and nuclear gauges; and decommissioning and environmental remediation. It also includes nuclear waste disposal and all phases of the nuclear fuel cycle, from uranium recovery to enrichment to fuel manufacture to spent fuel storage and transportation.

And there’s more. The program also does environmental reviews and oversees 37 Agreement States, which have assumed regulatory authority over nuclear materials, and maintains relationships with states, local governments, federal agencies and Native American Tribal organizations.

As with all organizations, the NRC’s workload has ebbed and flowed in response to a multitude of factors. Over the years, NMSS went through several structural changes to address its workload changes. In 2006, NMSS was gearing up for an increase in licensing activity related to the processing, storage and disposal of spent nuclear fuel. At the same time, the Agreement State program was growing, requiring additional coordination with the states—a function then housed in a separate Office of State and Tribal Programs.

To meet these changes and ensure effectiveness, the NRC restructured NMSS. Some of its programs were moved, including the state and tribal programs, into the new Office of Federal and State Materials and Environmental Management Programs (FSME). NMSS retained fuel cycle facilities, high-level waste disposal, spent fuel storage, and radioactive material transportation. FSME was responsible for regulating industrial, commercial, and medical uses of radioactive materials and uranium recovery activities. It also handled the decommissioning of previously operating nuclear facilities and power plants.

The NRC’s materials and waste management workload has now shifted again. At the same time, the agency is exploring ways to reduce overhead costs and improve the ratio of staff to management.

So, NRC staff launched a working group last fall to review the organizational structure of the NRC’s materials and waste management programs. With the focus shifting to long-term waste storage and disposal strategies, and an increasing number of nuclear plants moving to decommissioning, the group recommended merging FSME’s programs back into NMSS.

NRC’s Commissioners approved that proposal last week, and the merger of the two offices will be effective October 5. We think this new structure will better enable us to meet future challenges. It will improve internal coordination, balance our workload and provide greater flexibility to respond to a dynamic environment.

Current work, functions and responsibilities at the staff level will be largely unchanged. The management structure will realign into fewer divisions, with fewer managers.

In their direction to the staff, the Commissioners asked for careful monitoring of the changes and a full review after one year. We fully expect these changes to improve our communications both inside and outside of the agency, and provide for greater efficiency and flexibility going forward.

“Negative Ion” Technology—What You Should Know

Vince Holahan, Ph.D.
Senior Level Advisor for Health Physics

 

You may have heard about colorful silicone wristbands and athletic tape infused with minerals that are supposed to release “negative ions.” You might even be wearing one. They are touted as improving balance and strength, enhancing flexibility and motion, and improving mental focus and alertness. They’ve been sold on the Internet or in retail stores across the U.S.

The minerals these products contain can vary from volcanic ash and titanium to less familiar ones such as tourmaline, zeolite, germanium and monazite sand. They may also contain naturally occurring radioactive elements, including uranium and thorium. In trace amounts, these materials do not warrant much attention. But the radioactive emissions—that is to say gamma rays—from several of these products were detected on entry to the country by U.S. Customs and Border Protection officials using radiation monitoring equipment.

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While they may be radioactive, these products are not expected to create any health impacts. The amount of radiation given off by these products is well below the level that would cause any health concern or illness, even if worn over several years.

But NRC licensing requirements for uranium and thorium depend on the amount of radioactive material present. We commissioned the Oak Ridge National Laboratory to do an analysis that found enough radioactive thorium in several ion technology products that they require an NRC license for manufacture, distribution and possession in the U.S.

NRC staff experts on radiation worked with federal agencies and state regulators to determine the most appropriate path forward. Products containing negative ion technology — that is to say containing licensable amounts of radioactive material — should not be sold at the present time because they have not been licensed, as required, by the NRC.

Anyone wishing to dispose of a negative ion product may simply put it in their trash. This is OK because, although the amount of radioactive material requires licenses for manufacture and sale, it does not require any special handling or disposal.

We cannot say whether these products work as advertised. If you have them or know someone who does, our best advice is to throw them away. Anyone with health concerns should talk to their doctor. In the meantime, we’ll continue to do all we can to make sure they are being regulated properly.

NRC Science 101: The What and How of Geiger Counters

Joe DeCicco
Senior Health Physicist
Source Management and Protection Branch
 

In earlier Science 101 posts, we talked about ionizing radiation and different types of radiation. In this post, we’ll look at the Geiger counter, an instrument that can detect radiation.

science_101_squeakychalkJust to recap, the core of an atom (the nucleus) is surrounded by orbiting electrons, like planets around a sun. The electrons have a negative charge and usually cancel out an equal number of positively charged protons in the nucleus. But if an electron absorbs energy from radiation, it can be pushed out of its orbit. This action is called “ionization” and creates an “ion pair”—a free, negatively charged electron and a positively charged atom.

Humans cannot detect creation of an ion pair through their five senses. But the Geiger counter is an instrument sensitive enough to detect ionization. Most of us have heard or seen a Geiger counter. They are the least expensive electronic device that can tell you there is radiation around you—though it can’t tell you the original source of the radiation, what type it is or how much energy it has.

How does it work? A Geiger counter has two main parts—a sealed tube, or chamber, filled with gas, and an information display. Radiation enters the tube and when it collides with the gas, it pushes an electron away from the gas atom and creates an ion pair. A wire in the middle of the tube attracts electrons, creating other ion pairs and sending a current through the wire. The current goes to the information display and moves a needle across a scale or makes a number display on a screen. These devices usually provide “counts per minute,” or the number of ion pairs created every 60 seconds. If the loud speaker is on, it clicks every time an ion pair is created. The number of clicks indicates how much radiation is entering the Geiger counter chamber.

You hear a clicking sound as soon as you turn on the speaker because there is always some radiation in the background. This radiation comes from the sun, natural uranium in the soil, radon, certain types of rock such as granite, plants and food, even other people and animals.

The background counts per minute will vary; the needle will move or the number will change even when there is no know radiation source nearby. Many different things cause this fluctuation, including wind, soil moisture, precipitation (rain or snow), temperature, atmospheric conditions, altitude and indoor ventilation. Other factors in readings include geographical location (higher elevations give higher counts), the size and shape of the detector, and how the detector is built (different chamber material and different gases).

geigercounterDepending on the elevation and the type of Geiger counter, a typical natural background radiation level is anywhere from five to 60 counts per minute or more. Because background radiation rates vary randomly, you might see that range standing in one spot. It is important to understand that the Geiger counter indicates when an ion pair is created, but nothing about the type of radiation or its energy.

Other types of instruments can provide an exposure rate (expressed as milliroentgen per hour or mR/hr). These counters must be calibrated to read a particular type of radiation (alpha, beta, gamma, neutron, x-ray) as well as the amount of energy emitted. The reading will only be accurate for that type of radiation and that energy level. And these instruments need to be calibrated regularly to be sure they are providing correct information over time.

For more sophisticated environmental radiation readings, check out the Environmental Protection Agency’s nationwide system, RadNet. Using equipment far more sensitive than a Geiger counter, it continuously monitors the air and regularly samples precipitation, drinking water and pasteurized milk.

Over its 40-year history, RadNet has developed an extensive nationwide “baseline” of normal background levels. By comparing this baseline to measurements across the U.S. states in March 2011, following the accident at the Fukushima reactors in Japan, the EPA was able to detect very small radiation increases in several western states. EPA detected radiation from Japan that was 100,000 times lower than natural background radiation—far below any level that would be of concern. And well below anything that would be evident using a simple Geiger counter, or even Geiger counters spread across the country.

If RadNet were to detect a meaningful increase in radiation above the baseline, EPA would investigate immediately. With its nationwide system of monitors and sophisticated analytical capability, RadNet is the definitive source for accurate information on radiation levels in the environment in the U.S.

By the way, the Geiger counter is also called a Geiger-Mueller tube, or a G-M counter. It was named after Hans Geiger, a German scientist, who worked on detecting radiation in the early 1900s. Walter Mueller, a graduate PhD student of Geiger’s, perfected the gas-sealed detector in the late 1920s and received credit for his work when he gave his name to the Geiger-Mueller tube.

The NRC Considers Amending Radioactive Release Regulations

Tanya E. Hood
Project Manager
Office of New Reactors
 
 

Part of the NRC’s mission includes making sure nuclear power plants control and monitor the very small amounts of radioactive material that might be released during normal operations. Filtering and otherwise maintaining a reactor’s cooling water can create radioactive gases and liquids. The amounts generated and released vary depending on a reactor’s design and overall performance. The primary regulations for radioactive emissions (also called radioactive effluents) from commercial nuclear power plants are in 10 CFR Part 50, Appendix I.

These rules are designed to keep normal airborne or liquid releases low enough that any public radiation dose would be a minute fraction of the dose from natural background radiation. Appendix I also requires U.S. nuclear power plants to further reduce potential doses as much as reasonably possible. This set of regulations includes requirements for plants to regularly sample their nearby environments.  The plant’s samples of air, water, milk, soil, vegetation, sediment and fish come from the property line, on-site, and from nearby towns.

quoteIn 2007, the International Commission on Radiological Protection published recommendations that account for updated scientific understanding of the way to calculate radiation doses. For the past few years we’ve been considering amending the NRC’s radiation protection regulations. We’ve talked with public interest groups, other federal and state agencies and the industries or individuals we regulate on the possibility.

The NRC’s Commissioners gave the staff direction about potentially amending these regulations in December 2012. The Commission told the staff to begin developing the regulatory basis for revising the NRC’s radiation protection regulations in 10 CFR Part 20 and regulations for radioactive effluents from commercial nuclear power plants in 10 CFR Part 50, Appendix I “to align with the most recent methodology and terminology [in the ICRP 2007 recommendations] for dose assessment.”

The NRC just held a meeting soliciting feedback on the development of a draft regulatory basis for updating 10 CFR Part 50, Appendix I in Savannah, Ga., on June 27, 2014. The attendees, either in person, on the phone or watching our webinar, gave us some great comments to consider.

We’ll continue the discussion later this summer by issuing an Advanced Notice of Proposed Rulemaking (ANPR) in the Federal Register. The notice will list future meetings and describe the regulatory process in more detail.

Based on feedback received from the public conversations and the ANPR, NRC staff will complete the regulatory basis and make a recommendation to the Commission on whether revisions that may affect how radiation dose is calculated, how it is measured and how radioactive effluents are reported annually are warranted. The NRC staff anticipates the regulatory process related to potential updates will take several years to complete.

Next week, NRC staff from several offices will participate in the 59th Annual Meeting of the Health Physics Society, in Baltimore, Md., and will participate in a technical session that will cover, in more detail, the NRC’s efforts on this issue. In addition, Chairman Allison Macfarlane will address this topic, among others, in the meeting’s opening plenary session.

Tracing How Radioactive Materials Are Used in Research

Betsy Ullrich
Sr. Health Physicist
Region I
 

scientistScientists have been using radioactive materials in research nearly as long as they’ve known there were radioactive materials.

Most radioactive materials are used in research as “tracers.” A radioactive element is attached to a compound in order to see what happens to the compound. In other words, the radioactive material is used to “trace” what happens to the compound. Making the compound with the radiotracer is referred to as “labeling” or “tagging” the compound.

Let’s suppose a scientist is developing a new pesticide for treating crops. In order to understand what happens to that pesticide, the scientist uses tritium to label the compound. The atom of tritium will replace one of the normal hydrogen atoms on that compound. Then the pesticide labeled with the tritium tracer will be applied to a plant in a greenhouse. Samples of the leaves, roots and soil will be collected periodically and tested to see whether there is tritium in the samples.

Then the scientist will know whether the pesticide stays on the leaves, is absorbed into the plant, or gets into the soil from the plant roots or from being washed off the leaves during watering (in a laboratory setting).  

By far, the most frequently used radionuclides for research are carbon‑14 (C14), tritium (H3), iodine‑125 (I125), phosphorus‑32 (P32) and sulfur‑35 (S35), which have low enough energies to be easily shielded with thin plastic. I125 emits low-energy gamma radiation which also is easily shielded by plastic or glass.

Only very small quantities of these radionuclides are used, usually measured in microcuries or nanocuries. Because it’s gotten more expensive to use and dispose of radioactive materials, scientists have developed alternate testing methods for many studies. However, some research still requires radioactive materials because they’re the best way to label and trace a compound.

The use of radioactive materials in research requires a license from the NRC or an Agreement State, and scientists who use radioactive materials are trained in radiation safety and their research methods.

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