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Radium Part III: The NRC’s Role

Richard Chang
Office of Nuclear Material Safety and Safeguards

Radium_Periodic Element Table

We’ve been writing in this series about radium—how it was discovered, how it was used, how it can impact human health. Today we want to explain where the NRC fits in.

As we said in our last post, the states originally oversaw radium use. In 2005, Congress gave the NRC authority over radium through the Energy Policy Act. In 2007, we put in place our regulations on the control, use, and disposal of radium. These rules made clear that the NRC oversees radium only after it has been purposely concentrated for use.

Because many states already had laws on radium, we took over regulatory oversight in phases. We had full oversight for radium in all states by August 2009 (either through states that regulate nuclear materials under agreements with the NRC, known as Agreement States, or directly in those states that remain under NRC jurisdiction).

In 2007 after our regulations were put in place, we began talking to the U.S. Navy about radium contamination at their sites. As we learned more about this program and talked with the other branches of the military, we began working to clarify our role in the remediation at military sites. During the same time, we became aware of two specific radium cleanup efforts by other federal agencies. The Environmental Protection Agency has done cleanup work at the former WaterburyClockWaterbury Clock Company, in Waterbury, Conn. The National Park Service is also involved in a cleanup project at Great Kills Park, in Staten Island, N.Y.

As we learned more about these projects, it became apparent that a critical step for us to take would be identifying historical commercial radium sites; many of which were many decades old. As such, we began to look for sites in our jurisdiction that may have radium, and to find out how much, if any, cleanup was done. There are no known health and safety issues at any of these sites, but we want to make sure they do not pose a risk.

We contracted with Oak Ridge National Laboratory to help us develop a full picture of commercial radium sites. The lab started by cataloging the different products developed and sold to the public in the early 20th century. Oak Ridge scoured existing publicly available literature, records and databases, identified sites where radium may have been used to make consumer goods and looked for any cleanup records. We received the final results in November 2015.

We are working to get more information about the sites under NRC jurisdiction. We will be reaching out to site owners. Our goal is to confirm that these sites do not pose a risk to public health and safety and the environment. We’ll keep you posted on our progress.

NRC Joins Five Other Agencies in Addressing Uranium Contamination on the Navajo Nation

Dominick Orlando
Senior Project Manager

 

Navajo coverLast year, after five years of work to reduce risks from uranium contamination on territory that is part of the Navajo Nation, the NRC, along with four other federal agencies, reported on our progress to Congress. This week, the five federal agencies issued a plan that spells out how we’ll continue coordinating that work for the next five years.

 The agencies’ second Five-Year Plan builds on lessons learned from the first five years. It reflects new information and defines the next steps to address the most significant risks to human health and the environment. The new plan commits us to working together to reduce these risks and find long-term solutions.

 In October 2007, Congress asked the agencies to develop a plan to address the contamination on Navajo land, which dates back to the 1940s when uranium was in high demand. The Navajo Nation had large uranium deposits but regulations were not what they are today and mining companies left extensive contamination requiring cleanup. Legislation and new regulatory provisions were put in place to address these issues.

 The 2013 report capped off a five-year program the agencies conducted, in consultation with Navajo and Hopi tribal officials, to address uranium contamination on their land. Part of this work was government-to-government consultations with the Navajo.

 The program was a joint effort among EPA, the NRC, the Department of Energy, the Bureau of Indian Affairs, the Centers for Disease Control and the Indian Health Service. It focused on collecting data, identifying the most imminent risks, and addressing contaminated structures, water supplies, mills, dumps, and mines with the highest levels of radiation. We also learned more about the scope of the problem and the work that still remains.

 The NRC’s role is to oversee the work done by DOE, which is the long-term custodian for three sites storing uranium mill tailings—a sandy waste left over from processing uranium—and one former processing site. We do that by reviewing and, if acceptable, concurring on DOE’s plans to clean up contaminated groundwater, visiting the sites to evaluate how DOE is performing long-term care activities, and reviewing DOE’s performance and environmental reports.

 We will work closely with EPA, DOE, the New Mexico Environment Department, and the Navajo during the cleanup of the Northeast Church Rock site—which EPA and Navajo officials identified as the highest priority site for cleanup. The NRC will also be part of outreach activities detailed in the plan, including participating in stakeholder workshops and contributing, as appropriate, to educational and public information activities.

 Five years from now, we look forward to being able to say that with close coordination among all the parties, we have continued to make major progress in addressing concerns about uranium contamination.

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.

NRC Joins Five Other Agencies in Reporting on Navajo Land Contamination

Maureen Conley
Public Affairs Officer
 

navajoThe government has made good progress in reducing risks from uranium contamination on Navajo land, five federal agencies told Congress in a report last week. EPA compiled the report with input from the NRC, the Department of Energy, the Bureau of Indian Affairs, the Centers for Disease Control and the Indian Health Service.

This report recaps work done since October 2007. At that time, Congress asked the agencies to develop a five-year plan to address the contamination, which dates back to the 1940s.

Demand for uranium skyrocketed near the end of World War II. The ore was needed for nuclear weapons manufacturing and later to fuel commercial power reactors. The Navajo Nation lands had large uranium deposits, but mining and milling then was not nearly as regulated as it is today. Mining companies left extensive contamination requiring cleanup.

In 1978 Congress passed a law to ensure that uranium mill waste (called tailings) would be safely managed into the future. Under that law, DOE is responsible for the long-term care and maintenance of four former mill sites: Tuba City, Ariz.; Shiprock, N.M.; Mexican Hat, Utah; and Monument Valley, Ariz.

The NRC oversees DOE’s work at those sites. For example, DOE is responsible for cleaning up contaminated groundwater at the sites. The NRC reviews those cleanup plans. DOE monitors disposal facilities for uranium mill tailings. The NRC observes DOE inspections at the sites. The NRC also reviews and comments on DOE’s performance and environmental reports.

While the NRC does not regulate mine cleanup, the agency will also be working closely with EPA, DOE, the New Mexico Environment Department, and the Navajo Nation during the cleanup of a contaminated mine site in Church Rock, N.M. This conventional strip mine operated from 1967 to 1982. EPA plans call for the mine waste to be disposed at the nearby Church Rock mill site, which must be done in compliance with NRC disposal regulations.

Over the past five years, NRC staff has met many times with members of the Navajo Nation. We will continue these oversight and outreach activities.

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