The safety of aging reactors

Attainment of safety with older reactors has two principal components. The first is upgrading of safety where necessary to meet current criteria, as shown by modern safety analysis. The second is avoidance of degradation from effects of chemical change, wear, and neutron irradiation. Methods of avoiding reduction of safety from all such causes are know and are found to be effective, so that long-term reduction in safety is not an insuperable barrier to continued use of the plants to generate electricity. The means exist and are generally being followed to ensure that Western reactors are brought to levels of safety in accordance with modern criteria. These include some hardware changes and substantial improvement in operating practices. Methods of surveillance and repair and replacement exist to ensure that deterioration with time does not reduce the level of safety, regardless of the form of deterioration. This is believed to be so even for the effects of low cycle fatigue, which is still under study