Although the rate of new orders for nuclear power plants is down dramatically and fewer plants are under construction, the number connected to the grid has steadily increased. This has prompted a shift of emphasis in nuclear safety from the design and construction of plants to their operation. At the same time, there is growing recognition that mere compliance with regulatory requirements is not enough, that excellence in operational safety must be achieved for the public to support renewed expansion of nuclear power. For its part, the IAEA is continuing to develop programmes that can help its Member States and operating organizations achieve this goal. Four of these - known by the acronyms OSART, OSIP, ASSET and IRS - are the subject of this article