Plutonium isotopes and radionuclides in corals around Weizhou land in Beibu Gulf, China

Plutonium isotopes in the coral were determined with chemical separation method using AG 1-X8 and AG-MP-1M anion exchange resins and sector field inductively coupled plasma mass spectrometry (SF-ICP-MS) in order to elucidate the activity concentration and source of Pu around Weizhou land in Beibu Gulf, China. Furthermore, the activity concentrations of other radionuclides (²³⁸U, ²²⁶Ra, ²³²Th, ¹³⁷Cs, ⁴⁰K and ²¹⁰Pb) were measured by a HPGe spectrometer. The activity concentration of ^240+239Pu in the coral is determined to be in the range of 8.95-27.84 mBq/kg. The ²⁴⁰Pu/²³⁹Pu atom ratios in the samples range from 0.173 to 0.225, indicating that the main source of plutonium in this area is global fallout while the contribution of PPG is about 30%. Further, the activity concentrations of ²³⁸U, ²³²Th, ⁴⁰K and ²²⁶Ra are determined to be in the range of 18.72-64.63, 1.37-20.8, 29.78-72.52 and 3.48-61.97 Bq/kg, respectively.