[en] Authors demonstrate results of experimental scale-model studies on functional characteristics of a check valve used in the safety system of a liquid-metal-cooled reactor. Check valve model fluid dynamic characteristics obtained in the course of experimental studies are shown in diagrams as functions of some design and operation parameters of the model

[en] Decay heat removal from fast reactor BN-1200 to atmosphere air is provided by passive emergency heat removal system (EHRS). Development of EHRS involved the following innovations: - passive check valve at the outlet of decay heat exchanger (DHX); - application of outlet damper of air heat exchanger (AHX) with passive elements; - natural circulation in all EHRS circuits. The following experiments were conducted using test facilities with water and sodium: - hydraulic testing of several options of DHX check valve are performed using scaled-down mockup; - hydraulic testing of full-scale mockup of check valve; - in the closed position of check valve diffusion like process was investigated (long-term testing); - experimental studies of thermohydraulic characteristics are performed using scaled-down reactor model with one EHRS loop. Comprehensive calculation justification of EHRS efficiency was performed using a new generation calculation code SOKRAT-BN. (author)

[en] To purify primary sodium in the advanced BN-1200 reactor plant, a purification system with cold traps has been used that are located in the reactor vessel (in-built purification system). Such decision has excluded external communications of the auxiliary system with radioactive sodium and respectively a possibility that sodium will outflow to compartments outside the reactor. The sizes of cold traps located in the reactor are small that has limited the sodium flowrate through them, impurity storage capacity, and has made it necessary to replace traps in the course of reactor plant operation. Cold traps include such main components of the conventional external purification system as sodium communications, a portion of the cooling circuit, flow meter devices, and electromagnetic devices (a pump and throttle pump) to ensure sodium circulation and to control the sodium flowrate. In the course of development, options have been considered to cool traps with argon, liquid sodium, and gallium. To validate operation of electromagnetic devices for the cold trap, a package of research activities and R&D activities has been done: - thermal irradiation studies have been done of sample electrotechnical materials intended for the electromagnetic pump and throttle pump. - mockups of the electromagnetic pump and throttle pump have been manufactured and tested. (author)

[en] To purify primary sodium in the advanced BN-1200 reactor plant, a purification system with cold traps has been used that are located in the reactor vessel (in-built purification system). Such decision has excluded external communications of the auxiliary system with radioactive sodium and respectively a possibility that sodium will outflow to compartments outside the reactor. The sizes of cold traps located in the reactor are small that has limited the sodium flowrate through them, impurity storage capacity, and has made it necessary to replace traps in the course of reactor plant operation. Cold traps include such main components of the conventional external purification system as sodium communications, a portion of the cooling circuit, flow meter devices, and electromagnetic devices (a pump and throttle pump) to ensure sodium circulation and to control the sodium flowrate. In the course of development, options have been considered to cool traps with argon, liquid sodium, and gallium. To validate operation of electromagnetic devices for the cold trap, a package of research activities and R&D activities has been done: - thermal irradiation studies have been done of sample electrotechnical materials intended for the electromagnetic pump and throttle pump. - mockups of the electromagnetic pump and throttle pump have been manufactured and tested. (author)

[en] Decay heat removal from fast reactor BN-1200 to atmosphere air is provided by passive emergency heat removal system (EHRS). Development of EHRS involved the following innovations: - passive check valve at the outlet of decay heat exchanger (DHX); - application of outlet damper of air heat exchanger (AHX) with passive elements; - natural circulation in all EHRS circuits. The following experiments were conducted using test facilities with water and sodium: - hydraulic testing of several options of DHX check valve are performed using scaled-down mockup; - hydraulic testing of full-scale mockup of check valve; - in the closed position of check valve diffusion like process was investigated (long-term testing); - experimental studies of thermohydraulic characteristics are performed using scaled-down reactor model with one EHRS loop. Comprehensive calculation justification of EHRS efficiency was performed using a new generation calculation code SOKRAT-BN. (author)