Updating Radioactive Materials Transportation Regulations

Emma Wong
Project Manager

10cfrIf you have ever wondered about the safety of packaging and transporting radioactive materials, now is the perfect opportunity to learn about it. The NRC is kicking off the process of updating our requirements in 10 CFR Part 71.

We do this periodically to reflect new information. Changes to international packaging and transportation standards published by the International Atomic Energy Agency, which serve as a standard for the U.S. and other nations, can also trigger revisions. Stringent safety requirements, as well as coordination among federal agencies, international regulators, and tribal, state and local officials, help to ensure radioactive materials shipments are made safely.

The U.S. Department of Transportation has primary responsibility for regulatory materials transport, while the NRC regulates packages for larger quantities. This structure provides many layers of safety.

When it is time to review our requirements, the NRC coordinates with DOT to ensure the two agencies have consistent regulatory standards. The process may take several years. We are also working to align our regulations with the IAEA’s.

To encourage public input, we are publishing an “issues paper” that outlines areas we have identified for possible revision. We’ll take comments on it for 60 days. We plan to use that input to develop a draft regulatory basis—a document that identifies a regulatory issue, and considers and recommends a solution. Once finalized, the draft regulatory basis will be made available for public comment. After taking comments on the draft, we can publish a final regulatory basis.

At that point, if our Commission agrees that revision to our requirements are needed, we would move into developing a proposed rule, then a final rule. Each step in the process takes about a year. Details on how to submit comments can be found in a Federal Register notice that will be published on November 21. This information and additional details about the rulemaking will be available on the federal rulemaking website.

We’re also planning a public meeting on Dec. 5-6 at NRC headquarters in Rockville, Md., to discuss the paper and answer questions. Details on participating, including by teleconference and webinar, can be found in our meeting notice.

img_0230While the regulations are being updated, the fact remains that radioactive materials are transported safely all the time. Millions of these shipments are made each year and arrive at their destination without incident. Occasionally, a carrier might be involved in a traffic accident. But in decades of experience, there has never been an accident that resulted in injury from exposure to the radioactive contents.

All shipments of radioactive material must also be made in compliance with DOT regulations. Smaller shipments pose extremely low risk. The larger the amount of radioactive materials, the more stringent DOT’s requirements are. DOT limits how much radioactivity can be transported in each package. That way, no transport accident involving these shipments would pose a significant health threat.

But what about larger amounts of radioactive materials? What about spent nuclear fuel?

In addition to meeting DOT requirements, larger shipments of radioactive cargo such as spent nuclear fuel and fissile material must meet NRC regulations for packaging and transport in Part 71. These regulations include very detailed requirements for shipping under normal conditions, as well as stringent tests to show the packages can withstand hypothetical severe accidents. These are the regulations we are updating now. If you would like to learn more about the transportation of spent fuel and radioactive materials, see our website.

Hitting the Road – How the NRC Makes Sure Radioactive Material Is Shipped Safely

Bernard White
Senior Project Manager

LWT in Air 2
The NAC LWT transport package Photo courtesy of NAC International

In September 2013, we talked about transportation of spent nuclear fuel and how we know it is safe. This month, we want to discuss the safety basis for transporting other types of radioactive material.

The NRC recently approved a package to transport high enriched uranyl nitrate. This material is left over from the production of medical isotopes used in millions of diagnostic procedures every year. This package is to be used to bring material currently stored in Canada, where the isotopes were made, to the Savannah River site in South Carolina. The shipments are part of a DOE program to take back high enriched uranium from countries to which the U.S. supplied it.

Our review did not address whether the shipment should be made. Nor is it specific to any route. It just looked at whether the proposed shipping package design meets our requirements for safe transport. We rigorously reviewed the information submitted by the cask designer, NAC International. We asked four sets of detailed questions and thoroughly reviewed the applicant’s responses. After two years of review and two face-to-face meetings, we have answers to all our questions and we’re satisfied that the package design meets all NRC requirements for safe transport.

The high enriched uranyl nitrate, which is a liquid, will be transported using special containers that were designed to prevent leakage. To ensure they do not leak, the containers are leak tested after fabrication and prior to transport, each time the container is filled. These containers must also be replaced once they have been in use for 15 months. Together, these requirements give the NRC confidence that the containers will not leak.

These leak-tight containers will be placed into specially-designed packages for transport. This package design has been used for 25 years to safely transport a wide variety of radioactive materials. The inner containers and the outer packaging together make up the transport package.

Our review of this transport package design gives us confidence that, even if there were to be a transport accident, radioactive material will not leak from the package; dose rates will not be high enough to cause harm to anyone; and a nuclear chain reaction will not occur. Packages are evaluated for conditions that mirror normal transportation as well as the forces the package may experience in a severe accident.

The conditions assessed for routine transport include rain, hot and cold temperatures, a drop that may occur during handling, and the vibration that we all feel in a car or riding on a train.

For accident conditions, the package must be shown to be able to withstand forces that are more severe than in a real-world accident. This is done by testing or evaluating the package in a sequence of stringent tests. We discussed these tests in detail in our September 2013 blog.

This package has been shown to be able to safely transport contents that are much heavier and more radioactive than the high enriched uranyl nitrate, including spent nuclear fuel. The dose rates from the package containing liquid uranyl nitrate will be much lower than when the package is loaded with spent fuel.

For all these reasons, the NRC Is confident the package design meets all our requirements for safe transport. We follow the same review process for every transport package design we receive. In every case, we make sure we thoroughly understand the design and all the analyses in the application. We ask questions, if necessary, and often perform our own analysis. In some cases, including this one, we impose special conditions to give added assurance of safety. Only when we are satisfied a design meets every NRC requirement will we issue an approval.

Nuclear Medicine and the NRC: How it Works for Us, Patients and Health Care Providers

Sophie Holiday
ACMUI Program Manager
 

One of the more interesting things to emerge from nuclear weapons development was the use of radioisotopes in medicine. Before the end of World War II, there wasn’t much in the way of peaceful uses for radioisotopes. But in 1946, the Manhattan Project found a way to use its weapons technologies for the common good. It used a reactor at Oak Ridge to produce isotopes that could be distributed widely for research, medicine and industrial uses.

The Oak Ridge reactor offered a new family of isotopes created when uranium atoms fission, or split apart. These “byproduct” materials have many uses. It works like this: Radioisotopes give off energy that can be detected as they move through the body, allowing them to be used as “tracers.” This allows technicians to view different processes of the body than can be seen on x-rays. In larger amounts, some isotopes can also be used to target and destroy tumors.

Today, about 17 million patients each year in the U.S. benefit from imaging with radioisotopes or are involved in research, according to the Society of Nuclear Medicine and Molecular Imaging. About 150,000 patients a year undergo radionuclide therapy.

More than half of the diagnostic procedures are cardiovascular studies. But nuclear medicine patients may have cancer, diabetes, even Alzheimer’s disease. Radioisotopes are also used for bone scans, to locate tumors, to treat infections, and for studies of the liver, kidney, and lungs. And new procedures are being developed all the time.

acmuiquoteThe NRC’s job is to review uses of radioisotopes in medicine and determine if they can be safe both for the patient and the medical personnel – as well as the public. To ensure the NRC has access to the best available information for our reviews, we rely on a committee of experts known as the Advisory Committee on the Medical Uses of Isotopes.

This committee is made up of 13 health care professionals from several disciplines, including nuclear medicine, nuclear cardiology, nuclear pharmacy, medical physics, patients’ rights advocacy and health care administration. There are also representatives from the Food and Drug Administration and an NRC Agreement State—a state that has assumed regulatory authority over certain radioactive materials used in their state. They are appointed by the Commission and serve four-year terms. They meet twice and have three teleconferences each year.

These committee members advise the NRC on technical and policy issues related to nuclear medicine. Last year, the committee provided advice on changes needed to our regulations on medical isotopes and trends in a relatively new therapy called Y-90 microsphere brachytherapy. This therapy uses tiny beads containing radioactive material to target and destroy liver tumors while preserving healthy tissue.

We recently named three new members to fill open seats on the committee. For more information, see the committee’s webpage.

Paving the Way To A Better Road

Betsy Ullrich
Sr. Health Physicist
Region I
 

When you mention radioactive material, many people automatically think reactor or medical facility. They’re not aware that radiation could be used right outside their door. One example — portable gauges containing sealed sources of radioactive materials are often used during construction or repair of roads.

roadconstructionWhen paving a new road, construction crews need to know the amount of moisture in a roadbed and the density of the bed so the new road will last for many years. Portable gauges use small quantities of radioactive materials in sealed sources to make these measurements without damaging the roadbed.

To ensure the roadbed is dense enough, a sealed source emitting gamma radiation is lowered from the portable gauge into a small hole drilled into the road bed, at a specific distance from the gauge. Inside the gauge, a detector measures the amount of radiation that travels through the soil from the bottom of the drilled hole. The denser the soil, the more gamma radiation will be absorbed by the roadbed material and not reach the detector. A computer program in the gauge calculates the density of the roadbed based on the amount of radiation that reaches the detector.

Similarly, a sealed source containing a small amount of radioactive material that emits neutrons can be used to determine the amount of moisture in a roadbed. Neutrons are absorbed by water in the roadbed material, and scattered by mineral and other solid materials. The neutron source remains inside the portable gauge, and a shutter is opened to allow the neutrons to be emitted against the road bed surface. A detector inside the portable gauge detects neutrons that are scattered back from the road bed surface. This is why such source-detector combinations are referred to as “backscatter” devices.

In this case, the more moisture in the roadbed, the more neutrons are absorbed and fewer neutrons are available to be scattered back into the detector. A computer program in the gauge calculates the amount of moisture in the roadbed material from the number of neutrons detected by backscatter.

Although there are other ways to obtain this information, they may take more time, or require more invasive methods to obtain samples for analysis.

The radiation from these sources is not detectable even a few feet away, as long as the devices are used as designed. Portable gauges must be used by workers trained in radiation safety and use of the devices. And, workers using the sources are required to keep the gauges with them at all times, unless they are locked or secured as required by regulation.

NRC and Agreement State inspectors periodically inspect the companies that are licensed to operate portable gauges to ensure they’re being used safely.