As radioactive human doses are calculated through food chain and exposure pathways, it is important to take a pathway analysis to determine all pathway contributions for further radiological environmental risk assessment. A challenge of contaminant fate and environmental pathway analysis is to handle a large number of environmental components and to assign proper calculation models to linked component pairs. This paper presents a model template called transfer pathway model template (TPMT) that stores transfer models to environmental class pairs. When a site-specific calculation scenario is built, a source–receptor transfer matrix (SRTM) is defined by the scenario. Then the calculation loops through all source–receptor component pairs in SRTM and apply proper models stored in TPMT to calculate the transfer factors. TPMT can be used as the component pathway verification template and model allocation template. This structure is used in an environmental risk assessment (ERA) application called IMPACT that has been applied for a number of nuclear power plants and uranium mines in Canada.