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