[en] The research and development (R and D) activities of the Radiochemistry Division of the Bhabha Atomic Research Centre (BARC), Bombay, during 1978 are reported in the form of individual summaries under the headings: reactor chemistry, heavy element chemistry, process chemistry, radioanalytical chemistry and services, nuclear chemistry, and instrumentation. Some of the highlights of the R and D activities are: (1) preparation of microspheres of uranium oxide and uranium-thorium oxides by sol-gel process, (2) study of vaporization thermodynamics of Th and U by transpiration and boiling techniques, (3) preparation and characterisation of uranium(III) sulphates and double sulphates by X-ray, thermal and infra-red analysis, (4) extraction of trivalent actinides and lanthanides by long chain amines from chloride solutions, (5) study of radiation chemical behaviour of U(VI) in hydrochloric acid and sulphuric acid media, (6) purification and concentration of neptunium by the primary and secondary amines, (7) development of gamma spectroscopic method for determination of isotopic composition of plutonium using low energy gamma rays of plutonium isotopes, (8) standardisation of method of determination of isotopic abundances of uranium at nanogram level by thermal ionisation mass spectroscopy, (9) extraction photometric determination of Pu(IV) and Np(IV) present in mixtures, (10) study of various aspects of nuclear fission such as charge distribution, mass distribution and fragment angular momentum in low energy fission of actinides, and (11) fabrication of: (a) spark counting unit for counting fission tracks in their plastic films, (b) autoranging alpha monitor to be used with fractionating column, (c) remote pipetter for use in hot cells and (d) a thermoluminescence unit for glovebox operation. (M.G.B.)