Safety is the state of being "safe" (from French sauf), the condition of being protected from harm or other non-desirable outcomes. Safety can also refer to the control of recognized hazards in order to achieve an acceptable level of risk.
Radiation isn't the only problem of burying radioactive waste deep underground — waste also produces dangerous gases. An EU-funded project has forged a better understanding of how waste gases flow around and out of geological repositories to help national organisations ensure the process is safe.