During the theoretical leakage design basis accident the reactor coolant flashes to steam in the drywell, pressurizing it rapidly.

Accidents caused by poor design, failure to follow listed safety procedures or other forms of human error are not considered to be beyond design basis accidents.

Each division (copy) of the ECCS is capable, by itself, of responding to the design basis accident.

Design-basis earthquake or design-basis event, the earthquake or event which a nuclear facility is built to withstand in a Design basis accident.

In the event of a worst-case emergency, called a "design basis accident" in NRC regulations, the containment is designed to seal off and contain a meltdown.

The Design Basis Accident (DBA) for a nuclear power plant is the most severe possible single accident that the designers of the plant and the regulatory authorities could imagine.

The terminology can be unclear, however, because a poorly handled design basis accident can result in conditions beyond what was considered likely, causing a beyond design basis accident.

The ECCS is designed to rapidly cool the core and make it safe in the event of the maximum fault (the design basis accident) that nuclear regulators and plant engineers could imagine.

Each nuclear plant in the US is designed to withstand certain conditions which are spelled out as "Design Basis Accidents" in the Final Safety Analysis Report (FSAR).

The Three Mile Island accident and the Chernobyl disaster are examples of design basis accidents becoming non design basis accidents largely due to failures to follow the written operating procedures.

Circumstances like the 2011 Tōhoku earthquake and tsunami were considered unlikely or impossible, and so the resulting Fukushima I nuclear accidents were described using this terminology as "beyond design basis accidents" or "non-design-basis accidents".

Beyond design-basis is a term used in engineering, especially the design of nuclear power plants, to describe conditions or a significant event in which a system was not designed or intended to safely operate, contrasted to a Design basis accident.

There is controversy over the Environmental Impact Assessment (EIA), which "does not contain adequate information on the seismic conditions, nor does it address beyond design basis accidents or give details of the potential impacts of decommissioning".

The VVER 1000 models at Temelin and elsewhere are closest to Western safety standards, have redundant emergency core cooling systems, a large containment and in general reflect consideration of a full spectrum of design basis accidents.

Underlying the change is the belief that the "design basis accident," or worst accident for which the reactor and containment were designed to cope, is not really the most serious accident that could occur, and that nuclear plants may be vulnerable to more severe events.

A design basis accident (DBA) or maximum credible accident (MCA) is a postulated accident that a nuclear facility must be designed and built to withstand without loss to the systems, structures, and components necessary to assure public health and safety.

Combination of passive and active safety systems provided for in the VVER-TOI project ensures that core will not be destroyed for not less than 72 hours from the moment of severe beyond design basis accident happening in case of any possible scenario.

PWR containments are typically large (up to 10 times larger than a BWR) because the containment strategy during the leakage design basis accident entails providing adequate volume for the steam/air mixture that results from a loss-of-coolant-accident to expand into, limiting the ultimate pressure (driving force for leakage) reached in the containment building.

As one of beyond design basis accident control facility VVER-TOI project includes corium trap, a unique Russian safety technology, which provides the guaranteed safety control through melt localizing and cooling in the terms of severe beyond design basis accident at the beyond-vessel stage of core-melt localization.