TABLE 4.2
fl,
CONTINUED
Laboratory Activity Measurements.
Claas
Measurement
Sample
Comments
A
Gammaactivity, doghouse
occ, AOCc,,
Precision better than +5 percent, except for
Ac
Gammaactivity, dip
A
A
Gammaactivity, end-window
Gammaactivity, well
AOC, aliquots,
tank, sea water
IC trays
Individual parti-
Aliquoting uncertainty with occasional presence
of solids in high specific~activity sample.
Precision better than +5 percent.
Precision for single particles +3 percent (Ref-
,
B
Gammaactivity, 4-7 ion chamber
A
B
Mo* assay, radiochemical
Radiochemical R-values,
product/fission ratios
Spectrometry R-values,
product/fiasion ratios
Relative decay rates, all
instruments
D
A
I.
AOC,-B
cles, aliquots
end portion of decay curves.
erence 28).
of most samples
Aliquots of most
Some skill required in operation; precision
samples
#5 to 20 percent at twice background (Reference 26).
Occ, cloud
Accuracy +1vU percent (Reference 34).
OCC, cloud
Accuracy of nuclide determination +20 to 25
Percent (Reference 34).
Occ, cloud, IC
Factor of 2 or 3; misidentification possible.
All required
With few exceptions, necessary decay corrections made from observed decay rates of
appropriate samples in counters desired.
Laboratory Physical and Chemical Measurements
Class
A
B
D
A
Measurement
Chioride content, slurry drops
Water volume, slurry drops
Identification, compounds and
elements of slurry solids
Solid particle weights
Sample
Comments
IC reagent film
IC reagent film
IC reagent films,
occ
IC trays, OCC,
unscheduled
A
Solid particle densities
c
Elemental composition, fallout
IC trays, OCC,
unscheduled
occ
D
Identification, compounds and
elements of slurry solids
Particle size~frequency
IC reagent film,
occ
IC trays
B-¢c
distributions, concentrations
and relative weights versus
time
.
Accuracy +5 percent (Reference 31).
Accuracy +25 percent (Reference 31).
Possible misidentification; small samples,
smaJ' number of samples,
Accuracy and precision +5 yg, leading to +1
percent or better on most particles (Refer-
ence 26).
Precision better than +5 percent.
Large deviations in composition from duplicate
trays; recovery loss, and possible fractionation, ~40 mg; honeycombinterference.
Possible misidentification; small samples;
sr il] number of samples.
Difficulties in recognition of discrete particles,
treatment of flaky or aggregated particles;
uncertain application of defined diameter to
terminal-velocity equations; tray backgrounds
and photographic resolution in smaller size
ranges.
IV. Radiation Characteristics Data
Clags
Item
A-C
Gamma-ray decay schemea
A-B
Fission-product-disintegration rates
N
B
B
r
at
above infinite
pl
Computed far ao7iime area te plane
veraus photon ene
rey
Absolute calibration, beta counter
Absolute calibration, doghouse counter
Comments
Amount of decay scheme data available dependent on
particular nuclide.
About +20 percent for time period considered (Reference 41).
Error asaumed small compared to errorsin fallout
concentration, radionuclide composition, and decay
scheme data.
Personal communication from J. Mackin, NRDL.
Uncertainty in disintegration rate of calibrating nuclides; dependence on gamma-ray decay schemes.
125