Image made using the COMSOL Multiphysics® software and is provided courtesy of COMSOL.
Nuclear waste repositories are now being built to store spent fuel rods for the next one hundred thousand years or so. This model shows a hypothetical case where a breach in the fuel bundle canister leads to leakage through a fracture in the surrounding rock and backfill in the tunnel above.
The Subsurface Flow Module is for engineers and scientists who want to simulate fluid flow below ground or in other porous media and also connect this flow with other phenomena, such as poroelasticity, heat transfer, chemistry, and electromagnetic fields. It can be used for modeling groundwater flow, the spread of waste and pollution through soil, the flow of oil and gas to wells, and land subsidence due to groundwater extraction. The Subsurface Flow Module can model subsurface flow in channels, saturated and variably saturated porous media, or fractures, and couple these to simulations of solute and heat transport, geochemical reactions, and poroelasticity. Many different industries need to deal with challenges within geophysics and hydrology. Engineers from the fields of civil, mining, petroleum, agricultural, chemical, nuclear, and environmental engineering often need to consider these phenomena as the industries they work in directly or indirectly (through environmental considerations) affect the Earth on which we live.
Contained within the Subsurface Flow Module are a number of tailor-made interfaces describing certain physics for the modeling of flow and other phenomena in subterranean environments. Known as physics interfaces, they can be combined and directly coupled to other physics interfaces within the Subsurface Flow Module, or with physics interfaces within any of the other modules in the COMSOL Product Suite. This includes coupling the poroelastic behavior described by the Subsurface Flow Module to nonlinear solid mechanics applications for soil and rock in the Geomechanics Module.
COMSOL gives you the flexibility to enter any arbitrary equations within the edit fields in The Subsurface Flow Module’s physics interfaces, which can be useful for defining geochemical reaction rates and kinetics in the interfaces for material transport. Yet, coupling these physics interfaces with the Chemical Reaction Engineering Module means that you can model many multi-species reactions with the easy-to-use physics interfaces for defining chemical reactions that this module contains. Integrating these two products is very useful for modeling the many reaction steps involved in the spread of nuclear waste from their repositories over thousands of years.