[en] Recent increase in the demand for conventional energy alternatives and limited renewable energy resources enhances the demand for nuclear energy being pollution free and cost effective energy source. Since India has adopted closed nuclear fuel cycle, reprocessing of nuclear waste generated during nuclear reactor operation plays an important role. Selective separation of long lived radio isotopes from the liquid waste reduces the radioactive burden on the environment also these isotopes play an important role in cancer diagnosis and therapy. Crystalline inorganic ion exchange materials possess high radiation, mechanical, and thermal stability compared to organic ion exchangers hence promising materials for selective separation of fission products from nuclear waste. In particular ⁹⁰Sr having specific activity 1.5 × 10² Ci/g, with half-life 28.8 years, present in large quantity as a fission product in nuclear waste. In view of this we have synthesized framework connected inorganic phosphates of Ce (IV) and Zr (IV) with monovalent potassium ions as exchangeable ions with ⁹⁰Sr in nuclear waste conditions with stoichiometry K₂Ln (PO₄)₂, Ln=Ce, Zr. Potassium ions present in the lattice are for charge balance reason, exchangeable in presence of ions of similar size and charge