[en] Monte Carlo calculations of the dose index and dose-equivalent index for fields of monoenergetic neutrons from thermal energies to 14.7 MeV are in progress. The evaluation of MgB₄O₇:Dy as thermoluminescent dosimeters is continuing. Some factors that limit the accuracy of TLD readings have been investigated. Prototypes of a new portable personal tritium monitor have been evaluated at various nuclear power stations and at CRNL. Various methods of correcting Geiger counter rates for large dead-time losses are under investigation. An area has been selected as the site for a large-scale tracer injection test where groundwater flow behaviour in an area of predominantly vertical movement will be studied and modelled. The project 'Bedrock-groundwater/Lake-connection' is underway. A new method for counting carbon-14 at low levels has been tested. The release of approximately 130 TBq (3500 curies) of tritiated water from the NPD site over a 7-day period in August has provided an opportunity to study dispersion in the Ottawa River. Work in the Radiation Biology Branch has dealt with both the nature of DNA damage by radiation and the response of cells as they attempt to repair this injury