By George Lobsenz

The government should consider establishing increased security controls on seven types of radioactive sources in addition to the 16 radionuclides now subject to federal tracking to prevent acquisition by terrorists or others intent on fashioning a radioactive “dirty bomb,” according to a new report by a federal interagency task force.

In a report sent to the White House Aug. 11, the Radioactive Source Protection and Security Task Force also said that while the Nuclear Regulatory Commission, Energy Department and other federal agencies had made substantial progress over the last four years in improving protection of “risk-significant” radionuclides widely used for industrial, commercial and medical purposes, long-term security issues were raised by the continuing lack of disposal capacity available to companies wanting to get rid of sources they no longer needed.

The task force, established under the Energy Policy Act of 2005, also said that the government should continue to focus on developing alternative technologies for industries now dependent on the radionuclides of greatest use or concern, such as americium-241, cesium-137, cobalt-60 and iridium-92. It said while alternatives were available for some radionuclides, “financial, logistical, functional, relative risk and disposal issues can impede the deployment of alternatives and their replacement of current operating technology.”

On one of the radionuclides of greatest concern–cesium chloride, which includes cesium-137 in a highly dispersible form–the report said an immediate phase-out was not feasible because those sources are “extensively used in a wide range of applications in medicine, industry and research with significant health benefits for patients.” It said a gradual phase-out was possible if alternative technologies became “technologically and economically viable,” and that in the meantime DOE and NRC were working to upgrade security at facilities with cesium chloride irradiators.

More broadly, the task force said that since its initial report to the president in 2006, it had reviewed some 3,715 radionuclides to determine if any should be added to the list of 16 now subject to federal controls.

Through this analysis, the task force found that “seven additional radionuclides could be of concern in limited situations when aggregated or in bulk quantities (e.g., at major and secondary suppliers and manufacturers).”

The seven are iron-55, carbon-14, strontium-82, iodine-125, iodine-131, tungsten-188 and gadolinium-153.

However, the task force said because those radionuclides are infrequently shipped or possessed in quantities sufficient to be of use in a radioactive dispersal device, it was making no specific recommendation about increased controls for those materials.

Of all the problems involved in protecting radioactive sources, the task force said one of the most important for the government to tackle was the lack of disposal capacity for companies using those materials.

The report said companies in more than 36 states had no access to the handful of regional low-level radioactive waste disposal facilities established under regional compacts, and that those firms with the most radioactive sources–those classified by the NRC as “greater than Class C” (GTCC) waste–were dependent on DOE to provide disposal facilities.

Further, the report noted that current regulations require that GTCC wastes be disposed of in a geologic repository unless alternative methods of disposal are developed by DoE and approved by the NRC. However, the only suitable geological repository for some GTCC waste would be the proposed Yucca Mountain facility in Nevada, which the Obama administration is trying to kill.

The task force, which includes officials from 14 federal agencies and two state organizations, said the FBI, DoE and other agencies had been working with companies to improve security of their radioactive source storage facilities, but that indefinite storage posed long-term risks.

“Every year, thousands of sources become disused and unwanted in the United States,” the report said. “Whole secure storage is a temporary measure, the longer sources remain disused or unwanted the chances increase that they will become unsecured or abandoned.

“These sources have been the focus of much interagency attention from a national security standpoint since the publication [of the task force’s initial] 2006 report” on radioactive source management, the report noted. “However, in many cases, disposal pathways are not currently available for disused sealed sources (and there are restricted options for storage of no-disposal-pathway waste).

“Continued coordinated effort is needed to make sure that comprehensive, sustainable disposal pathways for all disused sealed sources are developed in the interest of national security.”

The report noted that Texas in 2009 had licensed the construction of a new disposal facility for certain classes of low-level radioactive waste, including disused used sources. While the facility is currently limited to companies in Texas and Vermont, the owner of the facility, Waste Control Specialists, is seeking to open it to companies in other states.

The task force also said DoE had helped dispose of some disused sources through its Global Threat Reduction Initiative. It said the department had determined that some sources were DoE waste and thus could be disposed of at existing DoE facilities.

The task force expressed particular concern about the lack of disposal capacity for U.S. companies holding Russian-origin americium-241, saying federal and state governments should look at options for providing short-term secured storage of that material.