TABLE 4.2
1,
CONTINUED
Laboratory Activity Measurements.
Class
Measurement
Sample
Comments
A ,
Gammaactivity, doghouse
AC
Gammaactivity, dip
A
A
Gammaactivity, end-window
Gammaactivity, well
B
Gammaactivity, 4-r ion chamber
A
B
Mo™ assay, radiochemical
Radiochemical R-values,
product/fission ratios
Occ, cloud
Occ, cloud
D
Spectrometry R-values,
OCC, cloud, IC
A
product/fiasion ratios
Relative decay rates, all
instruments
i.
occ, AOC,,
AOC,-B
AOC, aliquots,
tank, sea water
IC trays
Individual particles, aliquots
of most samples
Aliquots of most
samples
Precision better than +5 parcent, except for
end portion of decay curves.
Aliquoting uncertainty with occasional presence
of solids in high specific-activity sample.
Precision better than +5 percent.
Precision for single particles +3 percent (Reference 26).
Some skill required in operation; precision
#5 to 20 percent at twice background (Reference 26).
All required
Accuracy +10v percent (Reference 34).
Accuracy of nuclide determination +20 to 25
percent (Reference 34).
Factor of 2 or 3; misidentification possible.
With few exceptions, necessary decay corrections made from observed decayrates of
appropriate samples in counters desired.
Laboratory Physical and Chemical Measurements
Class
A
B
D
Measurement
Chloride content, slurry drops
Water volume, slurry drops
Identification, compounds and
elements of slurry solids
Solid particle weights
A
Sample
Comments
IC reagent film
IC reagent film
IC reagent films,
occ
IC trays, OCC,
unscheduled
A
Solid particle densities
c
Elemental composition, fallout
D
Identification, compounds and
elements of slurry solids
Particle size-frequency
distributions, concentrations
and relative weights versus
time
B-c
IC trays, OCC,
unscheduled
occ
.
IC reagent film,
occ
IC trays
Accuracy +5 percent (Reference 31).
Accuracy +25 percent (Reference 31).
Possible misidentification; small samples,
sma)’ number of samples.
Accuracy and precision +5 yg, leading to +1
percent or better on mostparticles (Reference 26).
Precision better than +5 percent.
Large deviations in composition from duplicate
trays; recovery loss, and possible fractiona~
tion, ~ 40 mg; honeycombinterference.
Possible misidentification; small samples;
err ill 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
Class
Item
Comments
A-C
Gamma-ray decay schemes
A-B
Fission-product-disintegration rates
N
Computed
r/br at 3 ft above infinite plane
photon/tims /area
versus photon energy
B
Absolute calibration, beta counter
B
Absolute calibration, doghouse counter
Amount of decay scheme data available dependent on
particular nuclide.
About +20 percent for time period considered (Reference 41).
Error assumed small comparedto errors in 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