US 4,053,359 A · Nuclear reactor

Abstract

A nuclear reactor in which the core components, including fuel-rod assemblies, control-rod assemblies, fertile rod-assemblies, and removable shielding assemblies, are supported by a plurality of separate inlet modular units. These units are referred to as inlet module units to distinguish them from the modules of the upper internals of the reactor. The modular units are supported, each removable independently of the others, in liners in the supporting structure for the lower internals of the reactor. The core assemblies are removably supported in integral receptacles or sockets of the modular units. The liners, units, sockets and assmblies have inlet openings for entry of the fluid. The modular units are each removably mounted in the liners with fluid seals interposed between the opening in the liner and inlet module into which the fluid enters and the upper and lower portion of the liner. Each assembly is similarly mounted in a corresponding receptacle with fluid seals interposed between the openings where the fluid enters and the lower portion of the receptacle or fitting closely in these regions. As fluid flows along each core assembly a pressure drop is produced along the fluid so that the fluid which emerges from each core assembly is at a lower pressure than the fluid which enters the core assembly. However because of the seals interposed in the mountings of the units and assemblies the pressures above and below the units and assemblies are balanced and the units are held in the liners and the assemblies are held in the receptacles by their weights as they have a higher specific gravity than the fluid. The low-pressure spaces between each module and its liner and between each core assembly and its module is vented to the low-pressure regions of the vessel to assure that fluid which leaks through the seals does not accumulate and destroy the hydraulic balance.

Claims3

Dependent claims

A liquid metal cooled nuclear reactor having a pressure vessel and also having means for supplying a cooling liquid metal to said vessel, a nuclear core in said vessel bounded below by a lower support plate and bounded radially by a core barrel, said core barrel forming an annular region between said barrel and said vessel, said annular region being at a lower temperature than said core, said core having a plurality of core assemblies for generation and control of energy of nuclear fission, a plurality of liners mounted in said lower plate, an inlet modular unit removably mounted in each said liner held by gravity, each said unit having receptacles for receiving certain of said assemblies, said assemblies being removable from their corresponding receptacles, each said modular unit being pervious to the flow of said liquid metal, said liquid metal flowing into said modular unit and into the receptacle of said modular unit and along said assemblies received in said receptacle in thermal interexchange with said assemblies and upwardly through said core, the flow of said liquid along said assemblies producing a pressure drop is said liquid so that liquid emerging from said core is at a lower pressure than liquid entering said receptacle, and means for producing low pressure regions below said modular unit and below said assemblies to produce a pressure balance on said modular unit and assemblies and to prevent the ejection of said modular unit from said liner and of said assemblies from said receptacle, said means comprising leakage flow paths below said modular unit and below said assemblies and by-pass flow vent-pipe means, said last-named means including a vent pipe disposed within said module and a plurality of flow passageways disposed horizontally through said lower plate to the outer periphery of said core barrel and said annular region, said leakage flow paths passing from below said modular unit and said assemblies to said vent-pipe and then through said passageways to the outer periphery of said core barrel and said annular region.

A nuclear reactor comprising:

a. a pressure vessel;
b. means for supplying a liquid metal coolant to said vessel;
c. a lower support plate within said vessel having flow passageways disposed horizontally therethrough;
d. a nuclear core in said vessel above said support plate, said core having a plurality of nuclear fuel assemblies, said assemblies comprising assembly coolant inlet openings;
e. a core barrel radially surrounding said core and affixed at its lower extremity to said support plate;
f. a plurality of liners mounted in said support plate, said liners disposed above, through, and below said support plate and comprising liner coolant inlet openings below said lower plate;
g. an inlet modular unit removably mounted in each said liner held by gravity, each said unit having receptacles for removably receiving certain of said core assemblies, each receptacle having receptacle inlet openings aligned with said assembly openings, each said modular unit being pervious to the flow of said coolant and further comprising module coolant inlet openings aligned with said liner coolant inlet openings and a vent pipe in flow communication with said passageways disposed through said support plate, said coolant flowing into said modular unit through said module openings and into the receptacles of said modular unit and along said assemblies received in said receptacles in thermal interexchange with said assemblies and upwardly through said core, the flow of said coolant along said assemblies producing a pressure drop in said coolant so that the coolant emerging from said core is at a lower pressure than coolant entering said receptacles;
h. first ring seals disposed between said assemblies and said receptacles above and below said aligned assembly and receptacle openings;
i. second ring seals disposed between said liners and said modular units above and below said aligned module and liner openings;
and
j. means for producing low pressure regions below said modular units and below said assemblies to produce a pressure balance on said modular units and assemblies and to prevent the ejection of said modular units from said liners and of said assemblies from said receptacles, said means comprising a liquid coolant flow path venting leakage passed said lower first ring seals and said lower second ring seals to lower pressure regions within said vessel, said lower pressure regions comprising an annular region formed between said vessel and said core barrel,
whereby said coolant leakage passes from below said first and second ring seals to said vent pipe, through said pipe to said passageways, and through said passageways to said lower pressure annular region.

9 more elements

A nuclear reactor comprising:

a. a pressure vessel;
b. a core including a plurality of nuclear fuel assemblies disposed within said vessel;
c. a cylindrical core barrel within said vessel radially surrounding said core;
d. an annular region formed between said core barrel and said vessel;
e. apparatus disposed within said annular region including fuel transfer storage containers and a reactor vessel thermal liner;
f. a liquid metal coolant circulating through said vessel, core, and annular region, said coolant being at a lower temperature and lower pressure within said annular region than within said core;
and
g. a structure disposed within said vessel below said core forming a singular lower coolant inlet plenum below said structure, said structure supporting said fuel assemblies and venting a portion of said liquid coolant from said lower plenum to said annular region and comprising:
i. a support plate having flow passageways disposed horizontally therethrough from within said plate to the periphery thereof;
ii. a plurality of liners permanently mounted in said plate extending above, through, and below said plate and having liner coolant inlet openings below said plate;
iii. an inlet modular unit removably mounted in each said liner having:
a. receptacles for removably receiving and providing coolant to said assemblies of said core,
b. modular unit coolant inlet openings aligned with said liner coolant inlet openings, and
c. a primary fluid flow path for passing coolant entering said module through said aligned openings upwardly to said receptacles,
iv. ring seals between said liner and modular unit above and below said aligned coolant inlet openings;
v. a vent pipe within each said modular unit in flow communication with the region between said liner and modular unit below the ring seal below said aligned openings and also in flow communication with said passageways;
whereby coolant from said lower coolant inlet plenum enters said liner through said liner coolant inlet openings and flows primarily into said modular unit and upwardly to said receptacles and said assemblies, and said coolant flows secondarily from below the ring seal below said aligned openings to said vent pipe, through said passageways, and into said annular region containing coolant at a lower temperature and lower pressure than coolant within said core.

14 more elements

Dependencies are inferred from the claim text.

Nuclear reactor

Life of this patent

Nuclear reactor

Life of this patent

Abstract

Claims3