Modular Helium Reactor (MHR) for oil sands extraction

Oil sands extraction is a very important industry for Canada, which continues to grow. It has been estimated that Athabasca region in northern Alberta has at least 1.6 trillion barrels of oil contained in oil sands, while the world liquid oil reserves are estimated as less than 1.0 trillion barrels. Strip mining can access only about 10% of the oil sand reserves, thus accessing most reserves involves in-situ technologies such as Steam Assisted Gravity Draining (SAGD). However, the SAGD process requires large amounts of high-temperature, high-pressure steam, which is currently being produced by burning natural gas. High-temperature nuclear reactors such as Modular Helium Reactor (MHR) present an alternative viable source of this steam, which can avoid the consumption of large amounts of natural gas and eliminate CO2 emissions. MHR technology has been under development in the US since the middle 1950s. It is the only nuclear technology demonstrated so far which is capable of achieving coolant outlet temperatures in the range of 700 - 1000oC. Several gas-cooled reactor plants have been built and operated to-date worldwide. The Modular Helium Reactor (MHR) has improved safety features, such as passive cooling. Coated fuel particles, annular core geometry with prismatic graphite elements used for the core structure material and as a moderator, along with helium as a coolant, distinguish the MHR from other gas cooled reactors and provide for its unique high-temperature and passive safety capabilities. Modularity is another important feature of the MHR. The 350 MW(t) MHR has been developed for electricity generation using a steam cycle, and has a net plant efficiency of 38.4%. One reactor module is capable of producing about 13,000 tons of steam per day. Such a reactor plant is therefore directly applicable to the oil sands extraction using the SAGD process. In this paper we present a flow diagram of a reactor plant co-producing electricity and steam for the SAGD process, with the use of a steam-to-steam re-boiler. With a steam-to-oil ratio as 2.5, one 350 MW(t) MHR unit provides steam and power for a 30,000 barrels per day oil sands extraction plant. Depending on the project, oil sands extraction plant may be required to expand over time. Such an expansion will be enabled by providing additional MHR units, thus taking advantage of MHR modularity.