RMI Nuclear Justice Documents

of plots relative to one another should take into account any environ-

mental factors such as prevailing wind directions and field drainage
patterns that would tend to confound (mix up) the clean-up treatment
The use of two or more control plots in appropriate locaeffects.

Also, an outline of the pertinent summary tables
and probable results expected from the study would be useful at the
planning stage, as would an outline of the statistical analyses to be
tions is advisable.

performed.

Careful attention to detail at the planning stage should

yield benefits over the long run.

One feature of the study will be, apparently, to measure the degree
of revegetation that occurs following the various clean-up treatments.
The particular variables used to measure this effect must be selected
with care to ensure that measurements obtained over time are truly

comparable.

Also, the variability in revegetation behavior from plot

to plot that will be induced by the probable inability to apply a
clean-up treatment with equal force to different plots suggests the
need to have replicate plots for each treatment.

Specifications of

the optimum number of replicate plots per treatment will be difficult
to ascertain due to lack of prior information.

Slight differences in

revegetation due to treatment effects are likely to go undetected.

INTERLABORATORY COMPARISONS

There is a need to continue the comparison of laboratories regarding
their analytical results for plutonium or other radioisotopes.
But there also needs to be a greater awareness of the limitations
of such studies, relative to being able to detect differences
between laboratories, when environmental samples are used.

There are basically two types of samples that can be used for interlaboratory comparisons:

"cross-check" and "standard" samples.

Cross-check samples are environmental samples (soil, vegetation,
etc.) collected either during the course of an ongoing field study,
such as at an NAEG study site, or as special field samples collected
with the express purpose of comparing laboratories' analyses.
111

Standard