Abstract: An integrated passive reactor system including a pressure vessel, a containment vessel arranged outside the pressure vessel, and a reactor core arranged inside the pressure vessel. A primary loop operates in full natural circulation. The reactor system is provided with a secondary side passive residual heat removal system including a primary loop heat exchanger arranged inside the pressure vessel and a passive residual heat removal heat exchanger arranged outside the containment vessel. The primary loop heat exchanger is arranged above the reactor core. The passive residual heat removal heat exchanger is arranged inside a water tank which is fixed outside the containment vessel. The primary loop heat exchanger and the passive residual heat removal heat exchanger are connected by heat exchanger inlet pipelines and heat exchanger outlet pipelines.

Abstract: Integrated passive reactor including a reactor primary circuit, a containment cooling system, a residual heat removal system, and a reactor core cooling system. Loop resistance is reduced by means of a reactor-type process design, a flow guide device is provided at a rising section of fluid to reduce the loop resistance, the rising section is shrunken to increase the arrangement space of a heat exchanger so as to further optimize system resistance, and the designs of an infinite-time passive reactor core residual heat removal system and an infinite-time passive containment cooling system are achieved. By means of the rational configuration of a pressure relief system, high-pressure safety injection is removed, and the passive reactor core cooling system is simplified. By means of the design of an auxiliary circulation device for a loss of coolant accident, the safety of a reactor core in the loss of coolant accident is further enhanced.

Abstract: An acousto-optic leakage monitoring system for main steam pipeline in nuclear power plant. The system includes an acoustic emission leakage monitoring loop and a spectrum leakage monitoring loop, wherein the signal input ends of the acoustic emission leakage monitoring loop and the signal input ends of the spectrum leakage monitoring loop are respectively arranged at detection points of the main steam pipeline. The signal output ends of the acoustic emission leakage monitoring loop and the signal output ends of the spectrum leakage monitoring loop are communicatively connected to each other through a network switch, and the network switch is sequentially connected with a control unit and a display unit.

Abstract: A head module for a large-scale container, a large-scale container having the head module, and methods for manufacturing the head module and the large-scale container. The method for manufacturing a head module comprises providing a head having an annular opening, the head being composed of a plurality of petals, providing a plurality of cylinder plates, and forming a head cylindrical ring, connecting in order the plurality of cylinder plates to the end surface of the annular opening and joining facing sides of all adjacent cylinder plates. Based on the unfitness of the petals at the annular opening of the head, gaps between adjacent cylinder plates may be adjusted, and/or the positions of the cylinder plates on the end surface of the annular opening of the head may be adjusted radially inwards or outwards.

Abstract: A gray control rod having a neutron absorber comprising terbium and dysprosium is provided. The neutron absorber comprises at least one first component and at least one second component, the reactivity worth of the first component increases as the service time of the neutron absorber increases, the reactivity worth of the second component decreases as the service time of the neutron absorber increases; the reactivity worth of the neutron absorber varying no more than 15% within the service time of the neutron absorber. By using the first component and the second component to form the neutron absorber, and adjusting the proportion of the respective components in the neutron absorber, the neutron absorber having a substantially planar reactivity worth loss characteristic can be obtained. The gray control rod and the assembly having required reactivity controlling ability can be obtained by increasing or decreasing the material dosage of the neutron absorber.

Abstract: A flow distribution device (3) for a reactor, a lower internals (100) of a reactor and a reactor are provided. The lower internals (100) includes: a lower core support plate (2) defining a coolant hole therethrough; a flow distribution device (3) mounted on the lower core support plate (2) and including a distribution annular plate (8) and a distribution bottom plate (9); a vortex suppression plate (7) disposed below the distribution bottom plate (9); a support column (4) defining an upper end connected with the lower core support plate (2) and a lower end passing through the distribution bottom plate (9) to connect with the vortex suppression plate (7); an energy absorption device (5) defining an upper end connected with the vortex suppression plate (7); and an anti-break bottom plate (6) disposed on the lower end of the energy absorption device (5).

Abstract: A heat pipe based passive residual heat removal system for a spent fuel pool (3). Partitions (6) are arranged around an inside of the spent fuel pool. Evaporation-end heat pipes (4) are arranged between the outside of the partitions and an inner wail of the pool. The evaporation-end heat pipes have outlets that extend beyond the pool and are connected to an Inlet of an ascending pipe (10), and have inlets connected to an outlet of a descending pipe (5). Condensation-end heat pipes (7) have inlets connected to an outlet of the ascending pipe, and have outlets connected to an inlet of the descending pipe. The heat pipes cool the spent fuel pool. A heat exchange by phase change of working medium in the heat pipe leads to heat exchange of low temperature difference and high efficiency, relying on density difference for natural circulation drive.

Abstract: A passive cooling system for a reactor core of a large-scale pressurized water reactor nuclear power plant includes a shield building having an outer wall and a through air inlet arranged on an upper part of the outer wall, a water tank arranged at an upper part of the shield building, a cooling water distribution plate arranged above a top of a containment within the shield building, a spray pipe arranged at an inside of the top of the shield building and having a water inlet end and a water outlet end, wherein the water inlet end is connected to a bottom of the water tank and the water outlet end is extended to be above the cooling water distribution plate, and an air deflector arranged between the shield building and the containment and having an upper end connected to an inside of the top of the shield building.

Abstract: A gray control rod, a neutron absorber thereof and a gray control rod assembly. The neutron absorber comprises at least one first component and at least one second component, the reactivity worth of the first component increases as the service time of the neutron absorber increases, the reactivity worth of the second component decreases as the service time of the neutron absorber increases; the reactivity worth of the neutron absorber varying no more than 15% within the service time of the neutron absorber. By using the first component and the second component to form the neutron absorber, and adjusting the proportion of the respective components in the neutron absorber, the neutron absorber having a substantially planar reactivity worth loss characteristic can be obtained. The gray control rod and the assembly having required reactivity controlling ability can be obtained by increasing or decreasing the material dosage of the neutron absorber.

Abstract: An apparatus for retention of molten material for a Generation IV reactor after a nuclear power plant accident comprises an inner wall which is peripherally closed, a vapor channel wall with an opening at the bottom fixed in the inner side of the inner wall, a pressure vessel disposed in the vapor channel wall, a vapor rising channel formed between the pressure vessel and the vapor channel wall, and it further comprises an outer wall surrounding the inner wall, a core molten material retention apparatus fixed at the bottom of the inner wall, and a deflector keeping away from the inner wall and the core molten material retention apparatus to form a gap; wherein a coolant falling channel is formed between the outer wall and the deflector, a coolant inlet is disposed at the bottom of the deflector, and a coolant channel is disposed between the inner wall and the core molten material retention apparatus; a core molten material retention recess is disposed at the upper surface of the core molten material retention

Abstract: A heat pipe based passive residual heat removal system for a spent fuel pool has a plurality of partitions (6) arranged around the inside of a spent fuel pool (3), wherein the heights of the partitions (6) are all lower than the height of the spent fuel pool (3); a plurality of evaporation-end heat pipes (4) are arranged between the outside of the partitions (6) and an inner wall of the spent fuel pool (3), and these evaporation-end heat pipes (4) are divided into several groups. Top outlets of each group of evaporation-end heat pipes (4) are extended beyond the spent fuel pool (3) and are connected to an inlet of an ascending pipe (10). An outlet of the ascending pipe (10) is connected to top inlets of a group of condensation-end heat pipes (7) comprising a plurality of condensation-end heat pipes. Bottom outlets of the group of condensation-end heat pipes (7) are connected to an inlet of a descending pipe (5).

Abstract: A passive cooling system for a reactor core of a large-scale pressurized water reactor nuclear power plant includes a shield building having an outer wall and a through air inlet arranged on an upper part of the outer wall, a water tank arranged at an upper part of the shield building, a cooling water distribution plate arranged above a top of a containment within the shield building, a spray pipe arranged at an inside of the top of the shield building and having a water inlet end and a water outlet end, wherein the water inlet end is connected to a bottom of the water tank and the water outlet end is extended to be above the cooling water distribution plate, and an air deflector arranged between the shield building and the containment and having an upper end connected to an inside of the top of the shield building.