Document: NRC Regulatory Guide
Document ID: 688895c2-d1d9-44f3-9c79-3cf0daa88510
Document Type: regulatory_guide
Title: 
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML0037/ML003739541.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.5
CFR Part: 
CFR Title: 

Content:
ansect. Press the 5-cm-depth topsoil cuttei into the ground without twisting or disturbing the grass cover or surface soil. This may best be accomplished by stepping on the rim of the cutter with both shoe heels. If more force is required to press the cutter into the ground, a rubber mallet may be used. Gently twist the handle of the cutter to cleanly remove the topsoil plug. Take a total of ten topsoil cores in a straight line, about 30 cm apart, placing the cores in a plastic bag. (The total area sampled is 620 cm 2.) Sometimes it may not be possible to remove a 5-cm-deep plug cleanly because of a thick root mat. If the topsoil and bottom soil are to be combined, a 10- or 15-cm-depth cutter may be used to remove the-topsoil by pounding it partway into the ground with the rubber mallet until it is possible to remove the core intact. Topsoil depth cannot be measured accurately by this method. C. Depth Profile An area where there are no rocks and stones and very few pebbles is suitable for taking soil samples at various depths. A sandy loam type soil such as is found on Cape Cod or eastern Long Island can be sampled satisfactorily. These conditions, of course, are rarely found in the areas of interest. Consequently,* the attempted use of the method described below runs the risk that subsoil layers may be contaminated with higher specific activity from upper layer soil. 1. Procedure As in the core sampling method, the depth profile samples are taken so that the weight and depth of the material collected can be directly related to the surface area. To the extent that grass cover and terrain affect the choice of sampling area, the site selection criteria previously described apply. Lay a tarpaulin (about 2 m square) on the ground near the clipped area. Dig a trench about 60 cm wide by 90 cm long by 60 cm deep immediately, adjacent to the clipped area, placing the removed dirt on the tarpaulin. Usually, the sod can be cut out in blocks, making it easy to replace after