Measurements of short-lived cosmic-ray-produced radionuclides in rainwater.
Cosmic-ray-produced (CP) nuclides with half-lives shorter than 21h were measured in rainwater by ultra-low-background gamma spectrometry at Ogoya Underground Laboratory. As levels of CP nuclides are extremely low and their half-lives are very short, quick sampling methods for a large volume of rainwater and rapid chemical separations by ion exchange method were developed. The nuclides measured were short-lived (24)Na, (28)Mg, (38)S, (38)Cl, (39)Cl, as well as nuclides with longer half-lives (7)Be and (22)Na. The number of atoms of CP nuclides in rainwater were evaluated to range from 30 to 1500L(-1) for (24)Na (n=16, mean; 520 [6.7mBqL(-1)]), 80 to 600L(-1) for (28)Mg (n=13, mean; 260 [2.4mBqL(-1)]), 400 to 1900L(-1) for (39)Cl (n=6, mean; 1200 [250mBqL(-1)]), 1x10(6) to 4x10(7)L(-1) for (7)Be (n=16, mean; 7x10(6) [1.05BqL(-1)]) and 2x10(3) to 1x10(5)L(-1) for (22)Na (n=9, mean; 2x10(4) [0.2mBqL(-1)]).
Komura
K
K
Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology (K-INET), Kanazawa University, Wake, Tatsunokuchi, Ishikawa 923-1224, Japan. komura@yu.incl.ne.jp
Kuwahara
Y
Y
Abe
T
T
Tanaka
K
K
Murata
Y
Y
Inoue
M
M
D001608:Beryllium / Q000032:analysis; D002713:Chlorine / Q000032:analysis; D003359:Cosmic Radiation; D004784:Environmental Monitoring / Q000379:methods*; D008274:Magnesium / Q000032:analysis; D011834:Radiation Monitoring; D011868:Radioisotopes / Q000032:analysis*; D011891:Rain; D012621:Seasons; D012979:Sodium Radioisotopes / Q000032:analysis; D013051:Spectrometry, Gamma / Q000379:methods; D013462:Sulfur Radioisotopes / Q000032:analysis; D013997:Time Factors; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D011868:Radioisotopes; D012979:Sodium Radioisotopes; D013462:Sulfur Radioisotopes; D014875:Water Pollutants, Radioactive; D002713:Chlorine; D008274:Magnesium; D001608:Beryllium