eae al tata
Radioactivity of Sea Water ~ Nuclide Aalysic
* Ryoji HIGANO, Masaru SHIUsZAKI
and Yoshiro SETO
1..:Sample
|
Twenty liters of sea water were collected from
the O, 150, and 300 m layers, respectively, at each
| station. As soon as the semple was collected, the
hydrogen ion concentration in the water was adjusted
@
to nearly pH 2 by adding concentrated HC1.
Analyzed
nuclides were 90Sr, 137Cs and léAce,
| 2. Procedure
Osr - After sea water was neutralized with a 10
M NaOH solution, the alkaline earth elements and
rare earth elements were separated from the sea
water as carbonate and hydroxide precipitates respectively. The precipitates were dissolved in hydrochloric
acid and the rare earth elements were separated from
the alkaline earth elements by neutralyzing the
hydrochloric acid solution with ammonia water.
er was separated from Ca by the fuming nitric acid
method and further purified chemically by repeating
the fuming nitric acid procedures two times and
radiochemically by scavenging with ferric hydroxide and
barium chromate. After leaving the purified Sr
fraction for two weeks, 70Y was separated by copre-
cipitation with ferric hydroxide and counted by a
14. gas flow counter.
13% cs - The carrier was added to the sample at
the rate of Img of Cs per liter of sea water.
Cs was
precipitated by adsorption of the Cs to the nickel
| ferrocyanide precipitate.
decomposed by heated #259,.
Nickel ferrocyanide was
Isolated Cs from the
precipitate was purified by the ammonium phosphonplybdate and chloroplatinate methods, and then cesium
chloroplatinate was filtered on filter paper and
counted bv Laz gas flow comter.
a *tydro graphic Division, Maritime Safety Board Agency,
—19—
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