Weekly, consecutive primary coolant samples from a boiling water reactor have been analyzed for239, 240Pu,238Pu+241Am,242Cm and244Cm for about two years, and for238Pu,241Pu and241Am for one year. Concentration ranges are reported. Samples were prepared for counting either directly by evaporation or by
chemical separation on BioRad AG 1×4 resin and subsequent electrolysis, and were counted in 20 cm dia Frish grid ionization
chambers. Procedures are described. For most actinide nuclides, activity ratios in primary coolant were found to be different
from those in worldwide fallout, thus allowing an identification of origin in the case, that actinides should be detected
in the vicinity of a nuclear power station.
Neutron activation analysis was used for provenance studies of ceramics from the early middle ages (avar period). 14 trace elements and Fe were determined by multiisotope comparator method. Computerized mathematical statistical methods (cluster-, and similarity analysis) were used for grouping the samples according to the similarity of their trace element distributions.
A chemical separation procedure is described which allows the direct determination of low241Pu activities in environmental samples with a windowless gas-flow proportional counter. While current separation schemes based on anion exchange yield counting sources of sufficient purity for subsequent -spectrometry, for -counting of241Pu additional purification steps are required. A combination of anion exchange from 9 mol/l HCl, LaF3 precipitation and TTA extraction was found to be suitable even for the analysis of long-range Chernobyl fallout samples which contained interfering radionuclides with -activities at least 3 to 4 orders of magnitude higher than usually encountered. No difference is detectable between the results of the present, direct procedure and the results of the conventional indirect method based on the build-up of241Am. Average241Pu/239+240Pu ratios in air and deposition samples taken at Neuherberg near Munich were 70±6 with the present procedure and 66±9 from241Am build-up.
Neptunium is sorbed, together with plutonium, uranium and iron on Bio Rad AG 1×4 anion exchange resin from 9 mol/1 HCl, eluted with 7 mol/l HNO3 and 1.2 mol/l HCl, purified on a second, identical column and electrodeposited on stainless steel discs.237Np is determined by -spectrometry,239Np by -spectrometry with a Ge detector, or via its 14.3 keV LX-rays in a Si(Li) measurement. The neptunium yield is determined from the count rate of the 13.6 keV LX rays of the tracer235Np in a later Si(Li) measurement. The average chemical yield is 78±11%. The detection limit for237Np is 1 mBq. The procedure allows the sequential determination of neptunium, together with plutonium, strontium, uranium and iron from one sample. The method was applied to air and total deposition samples from Munich-Neuherberg and to sediment samples from the Irish sea.