Economic feasibility of strontium-90 fueled heaters for use in cold regions

This study was conducted to conceptually design and obtain cost estimates for various radioisotope fueled heating systems for use in potential cold regions applications, and to determine the economic feasibility of radioisotope fueled heaters by comparing them to fuel oil systems. The applications have been identified and grouped, according to thermal output: (1) 1 kWt septic tank heaters, well-head heaters, heaters to assist operation of sewage lagoons, and (2) 7 or 12 kWt potable water system heaters. Potentially economic locations for these heaters are in remote Alaskan communities of 50 to 200 residents, where fuel oil prices and reliability requirements are high. Two basic conceptual heat designs were considered: a heat source and radiation shielding with no external heat transfer equipment, and a heat source and radiation shielding with external heat transfer equipment. Costs for both conceptual designs were estimated for heater sizes of 1 kWt, 7 kWt, and 12 kWt. The major costs were for the heat source and equipment. Radioisotope heaters were found to be much more expensive than fuel oil systems. The radioisotope fuel costs contribute 50 percent or more to the overall cost. Thus, an effective method to make a substantial reduction in radioisotope system costmore » would be to lower the Sr price from 10 cents/curie. It was concluded that radioisotope heaters will not be economically competitive with fuel oil systems unless one or more of the following situations occur: the price of strontium-90 is reduced below 10 cents/curie; fuel oil prices increase significantly; or for a particular application, the reliability or adaptability of a fuel oil system is unacceptable and a radioisotope system is satisfactory.« less