The most important safety issues are well-known and were analysed during the construction of previous research facilities in Great Britain and Switzerland, which, like ESS, is based on spallation technology. The two new spallation sources that have now been completed in the USA and Japan will provide further experience. In a preliminary safety assessment, Studsvik AB has determined that “ESS can be constructed with such a high standard of safety that it can be built and operated anywhere in Sweden with a minimum of environmental impact”.
A strict safety philosophy will pervade both the construction and the operation of the facility. In addition, the system is designed so that toxic or radioactive material will not be able to leak from the facility in harmful quantities.

The risk of an accident occurring will be very low. The substances that constitute a potential danger are contained in an entirely closed system. A risk analysis will be carried out to ensure that all possible safety and precautionary measures are taken. The accident scenarios that are extremely likely and would have very minor consequences for personnel and the general public will also be taken into account in the design of the facility.
There is no reason for worst-case-scenarios. The world’s leading spallation facility, ILL in Grenoble, has planned for an evacuation zone of 500 metres around the facility in its risk analysis of worst possible accidents. ESS will contain significantly less radioactivity than ILL.
The Swedish Environmental Code, the Swedish Radiation Protection Act and the Swedish Planning and Building Act prescribe which risk assessments and applications should be carried out. A risk assessment will be submitted to the authorities responsible prior to the permit applications. It will be meticulously tested by the authorities that issue the permits whether safety at ESS is satisfactory.
Building ESS so that it passes the permit application is a condition of the Swedish government's offer to be host.