A system comprising: an integral pressurized water reactor disposed in a containment structure, the integral pressurized water reactor including an internal steam generator and a nuclear core configured to be immersed in primary coolant water, the nuclear core comprising fissile material; a steam line connected to an outlet of the steam generator and passing through the containment structure configured to convey steam from the internal steam generator; a feedwater line connected to an inlet of the steam generator and passing through the containment structure configured to convey feedwater into the internal steam generator; a condenser disposed outside the containment structure; a condenser inlet line tapping off the steam line at a point outside the containment structure and feeding into an inlet of the condenser; and a condensate injection line configured to convey condensate from an outlet of the condenser into the steam generator; an isolation valve on the condensate injection line and isolation valves (518, 524) outside the containment structure on the feedwater line and on the steam line, wherein the valves are configured to have: an operating configuration in which the isolation valves on the feedwater line and on the steam line are open and the isolation valve on the condensate injection line is closed, and a heat removal configuration in which the isolation valves on the feedwater line and on the steam line are closed and the isolation valve on the condensate injection line is open; a bleed valve connecting the condensate injection line with the feedwater line, the bleed valve configured to be open in the operating configuration to keep the condenser in a hot standby state and closed in the heat removal configuration. an integral pressurized water reactor disposed in a containment structure, the integral pressurized water reactor including an internal steam generator and a nuclear core configured to be immersed in primary coolant water, the nuclear core comprising fissile material; a steam line connected to an outlet of the steam generator and passing through the containment structure configured to convey steam from the internal steam generator; a feedwater line connected to an inlet of the steam generator and passing through the containment structure configured to convey feedwater into the internal steam generator; a condenser disposed outside the containment structure; a condenser inlet line tapping off the steam line at a point outside the containment structure and feeding into an inlet of the condenser; and a condensate injection line configured to convey condensate from an outlet of the condenser into the steam generator; an isolation valve on the condensate injection line and isolation valves (518, 524) outside the containment structure on the feedwater line and on the steam line, wherein the valves are configured to have: an operating configuration in which the isolation valves on the feedwater line and on the steam line are open and the isolation valve on the condensate injection line is closed, and a heat removal configuration in which the isolation valves on the feedwater line and on the steam line are closed and the isolation valve on the condensate injection line is open; an operating configuration in which the isolation valves on the feedwater line and on the steam line are open and the isolation valve on the condensate injection line is closed, and a heat removal configuration in which the isolation valves on the feedwater line and on the steam line are closed and the isolation valve on the condensate injection line is open; a bleed valve connecting the condensate injection line with the feedwater line, the bleed valve configured to be open in the operating configuration to keep the condenser in a hot standby state and closed in the heat removal configuration.