[ RadSafe ] Soil Blending

Schmidt, Duane Duane.Schmidt at nrc.gov
Thu Nov 8 17:12:31 CST 2012

Pete C, et al:

I just wanted to let you know that the NRC staff has some guidance on the topic of intentional (purposeful) mixing (blending) of soil to meet the license termination rule. That guidance is in NUREG-1757, Vol. 1, Rev. 2 (September 2006), Section 15.13. See our web page at:


A brief summary follows, but please read the guidance if you want to implement it.

Typically, intentional mixing is not used to achieve the license termination rule dose criteria (or DCGLs). However, the guidance states that intentional mixing can be approved on a case-by-case basis in limited circumstances. Some of the limitations are:

- The NRC staff will consider only cases in which the intentional mixing is part of an overall approach to site cleanup that is ALARA - the ALARA evaluation of the overall approach must support the use of mixing instead of other approaches (i.e., soil removal).

- The intentional mixing should not be the sole means to achieve the license termination dose criteria.

- The footprint (areal extent) of residual radioactivity should not be increased as a result of the intentional mixing.

- Uncontaminated soil from outside the contaminated zone should generally not be used.

More details are provided (on these limitations and other aspects) in the guidance, and some of the details may be critical.

Please note that some Agreement States may not endorse the NRC guidance on intentional mixing (NRC does not speak for States).

In addition, NRC decommissioning staff recommends (strongly) that licensees consult with their regulator (NRC or State or other) in advance about a proposal to use intentional mixing.

Sorry for the caveat, but... This e-mail does not constitute NRC staff guidance - the guidance is in NUREG-1757.

Hope this helps,



Duane Schmidt, CHP

Senior Health Physicist

U.S. Nuclear Regulatory Commission


Mail Stop T-8F5

11545 Rockville Pike

Rockville, MD 20852


duane.schmidt at nrc.gov<mailto:duane.schmidt at nrc.gov>

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Peter Collopy
Sent: Wednesday, November 07, 2012 6:22 PM
To: radsafe
Subject: [ RadSafe ] Soil Blending

I have been working with a client who has somehow latched onto the idea they could blend soil to lower the overall radionuclide concentations in soil to make the soil acceptable for disposal on the site of origin. In my opinion the only way that could be done would be to submit to the NRC or the agreement state an exemption request to do that type of operation. My client has asked, and as a dutiful consultant I am acceding (reluctantly) to their wishes, that I find out if anyone has ever been allowed to do a purposeful blending operation with the objective of on-site soil disposal. So here are my two questions:

1. Have you ever heard of soil blending being allowed on a U.S. site for the purpose of lowering the concentrations to below the DCGL and thus meeting free release criteria for the site.

2. If the answer to 1 above is yes did they apply for an exemption from the NRC or agreement state or did they simply do the work as part of an approved Decommissioning Plan?

If you wish to keep any info on the QT just email me directly or call but keep in mind I am on the west coast so early moring risers on the east coast  try not to call at 7:00 your time.

Thanks for any info in advance

Pete C

Peter Collopy, CIH, CHP, CSP

Director, Entropy Control

Chaos for the Future

3940 7th Avenue

San Diego CA

518.326.6413 (yes I kept my NY cell #)


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