A passive containment cooling system (PCCS) condenser, for reducing some non-condensable gases in the PCCS, includes a first and a second stage condenser that each include channels in fluid communication between an inlet and an outlet header. The inlet header of the first stage condenser is configured to receive a fluid mixture through a first inlet opening. The channels are configured to condense water from the fluid mixture flowing through the channels from the inlet header to the outlet header, respectively, of the first and second stage condenser. The PCCS condenser includes a catalyst in at least one of the outlet header of the first stage condenser or the inlet header of the second stage condenser. The catalyst catalyzes a reaction for forming water from hydrogen and oxygen in the fluid mixture. The outlet header of the second stage condenser is in fluid communication with a combined vent-and-drain line.

A method for the manufacture of a three-dimensional object using a refractory matrix material is provided. The method includes the additive manufacture of a green body from a powder-based refractory matrix material followed by densification via chemical vapor infiltration (CVI). The refractory matrix material can be a refractory ceramic (e.g., silicon carbide, zirconium carbide, or graphite) or a refractory metal (e.g., molybdenum or tungsten). In one embodiment, the matrix material is deposited according to a binder-jet printing process to produce a green body having a complex geometry. The CVI process increases its density, provides a hermetic seal, and yields an object with mechanical integrity. The residual binder content dissociates and is removed from the green body prior to the start of the CVI process as temperatures increase in the CVI reactor. The CVI process selective deposits a fully dense coating on all internal and external surfaces of the finished object.

A block style heat exchanger for a heat pipe reactor having a plurality of heat pipes extending from a reactor core. The heat exchanger includes a plurality of primary channels, each for receiving heat transferred from the core via one of the heat pipes. The primary channels extending within a block of one or more materials. The heat exchanger also includes a plurality of secondary channels defined within the block for transmitting a flow of the secondary heat transfer medium through the heat exchanger from an inlet to an outlet. The block is formed from one or both of: a plurality of plates bonded together, with each plate defining at least a portion of one or more of the plurality of primary channels and/or the plurality of secondary channels, and/or a unitary piece of material formed from an additive manufacturing process.

A heat exchanger may include a main body with an inlet plenum and an outlet plenum at a first end, and a header at a second end. At least one elongated shaft may extend from the outlet plenum to the header. At least one heat pipe may be coupled to the header and a portion of each heat pipe may be positioned within a corresponding elongated shaft defining an annular space between each heat pipe and each corresponding elongated shaft. A flow skirt may include a manifold located between the inlet plenum and the outlet plenum of the main body. At least one elongated tube may extend from the manifold. Each elongated tube may be positioned within a corresponding annular space between each heat pipe and each corresponding elongated shaft, dividing the annular space into two concentric annular channels comprising an inner annular channel and an outer annular channel.

A heat transfer module can include an envelope sealed to define an internal volume that contains a working fluid and a wick disposed on an internal surface of the envelope. The wick and envelope each has a first portion extending through an evaporator region and a second portion extending through adiabatic and condenser regions. The first portion of the wick is a metal hydride. The first portion of the envelope includes a metal liner surrounding the first portion of the wick, a first diffusion barrier layer disposed between the first portion of the wick and the metal liner, and a ceramic matrix composite cladding surrounding the metal liner. The second portions of the wick and envelope each includes a refractory metal and/or stainless steel.

The present invention provides a heat transferring device and a method for making thereof. The heat transferring device has a thermal conducting substrate and a porous layer. The thermal conducting substrate has a plurality of protrusions and concave bottom surfaces. The concave bottom surfaces are located between the protrusions. The porous layer is embedded between the protrusions. The present invention also provides a high temperature material transferring system comprising a cylindrical container and the heat transferring device disposed on the surface of the cylindrical container.

Technique(s) to mitigate creep and/or cascade failure in high temperature heat pipe reactor cores may include gas loading each heat pipe such that when one or more heat pipes in the heat pipe array fail, the adjacent heat pipes can accommodate added heat load with little change in temperature.

A system for transferring heat from a nuclear reactor comprises a nuclear reactor comprising a nuclear fuel and a reactor vessel surrounding the nuclear reactor and a heat transfer system surrounding the nuclear reactor. The heat transfer system comprises an inner wall surrounding the nuclear reactor vessel, first fins coupled to an outer surface of inner wall, an outer wall between the inner wall and a surrounding environment, and second fins coupled to an inner surface of the outer wall and extending in a volume between the outer surface of the inner wall and the inner surface of the outer wall, the outer surface of the inner wall and the first fins configured to transfer heat from the nuclear reactor core to the second fins and the inner surface of the outer wall by thermal radiation. The heat transfer system may be directly coupled to the nuclear reactor vessel, or may be coupled to an external reflector surrounding the nuclear reactor vessel. Related heat transfer systems and systems for selectively removing heat from a nuclear reactor are disclosed.

A printed circuit heat exchanger for use in a reactor includes a core formed from a stack of plates diffusion bonded together. The core has: a top face, a bottom face disposed opposite the top face, a first side face extending between the top face and the bottom face, and a second side face disposed opposite the first side face. The printed circuit heat exchanger includes: a plurality of primary channels defined in the core, each of the primary channels extending from a primary inlet defined in the first side face to a primary outlet defined in the second side face; and a plurality of secondary channels defined in the core, each of the secondary channels extending among at least some of the primary channels from a secondary inlet defined in the top face to a secondary outlet defined in the top face.

A heat exchanger module with a longitudinal axis including a stack of plates defining at least two fluid circuits, at least a portion of the plates each including fluid circulation channels each delimited, at least in part, by a groove. A communication is produced between the channels within a same plate and between all the plates of a same circuit, in a feed or pre-collector zone, with a succession of channel groupings, two-by-two, in the form of bifurcations.