skip navigation links 
Index | Site Map | FAQ | Facility Info | Reading Rm | New | Help | Glossary | Contact Us blue spacer BrowseAloud
secondary page banner Return to NRC Home Page

Backgrounder on Blending of Low-Level Radioactive Waste

Printable Version PDF Icon

Recently, industry has expressed increased interest in blending certain types of low-level radioactive waste in order to lower the overall concentration of radioactivity and make the waste more suitable for disposal. This interest prompted NRC Chairman Gregory B. Jaczko to direct the staff to develop a vote paper for the Commission to address policy issues related to blending. That paper is due in April 2010.


Low-level radioactive waste (LLW) is classified at the time of disposal according to its radioactivity and the measures necessary to protect the public and the environment from unnecessary exposure after disposal. Most LLW (about 95 percent) is Class A, the lowest concentration category. Remaining radioactive wastes are either Class B or Class C, depending on their radioactivity. (Concentration is the total amount of radioactivity divided by the weight or volume of the waste.)

In July 2008, the LLW disposal facility at Barnwell, S.C., closed to much of the nation. This left waste generators in 36 states with no disposal options for their Class B and Class C wastes. To help mitigate the impact of Barnwell’s closing, industry has proposed approaches for blending higher activity LLW (Class B and Class C) with lower-activity waste (Class A) to form a Class A mixture that can be disposed of at EnergySolutions’ Clive, Utah, disposal facility. This facility accepts only Class A waste and is open to the entire country. (A third LLW disposal site, operated by U.S. Ecology in Richland, Wash., accepts Class A, B and C waste from 11 states in the Northwest and Rocky Mountain regions.)

NRC regulations do not prohibit blending to lower the waste classification, nor do they explicitly address the issue. The agency in the past has issued guidance that discourages blending to lower waste classification in some circumstances, but acknowledges that blending may be appropriate if it increases operational efficiency or reduces worker exposure to radiation.

Blending of LLW means mixing wastes of different concentrations to form a homogeneous mixture for disposal in a licensed LLW disposal facility. It does not mean mixing LLW with non-radioactive waste, a practice known as “dilution.” And it does not imply release of radioactive material to the general environment, either to municipal landfills or to consumer products. Because of the need for a homogeneous mixture, the wastes under consideration for blending are primarily resins and filter media used to clean contaminated water at commercial nuclear power plants.

Chairman Jaczko’s Direction

On Oct. 8, 2009, NRC Chairman Jaczko directed the staff to develop within six months a vote paper for the Commission’s consideration addressing potential policy issues associated with blending of LLW. The Chairman specifically asked the staff to address the following issues:

  • Issues related to intentional changes in waste classification due to blending, including safety, security, and policy considerations;
  • Protection of the public, the intruder, and the environment;
  • Mathematical concentration averaging and homogeneous physical mixing;
  • Practical considerations in operating a waste treatment facility, disposal facility, or other facilities, including the appropriate point at which waste should be classified; and
  • Recommendations for revisions, if necessary, to existing regulations, requirements, guidance or oversight related to blending of LLW.

Public Involvement

Following Chairman Jaczko’s directive, the NRC issued a Federal Register notice on Nov. 30, 2009, requesting public comment (through Jan. 29, 2010) on these and other questions. NRC staff held public meetings Dec. 14 and 15, 2009, with three companies that had expressed views on blending of LLW: EnergySolutions, Studsvik, and Waste Control Specialists. The NRC also announced plans for a public workshop Jan. 14, 2010, in Rockville, Md., for interested stakeholders to present their views on blending.

January 2010

Privacy Policy | Site Disclaimer
Thursday, January 07, 2010