公开(公告)号：US12217881B2

公开(公告)日：2025-02-04

申请号：US18451885

申请日：2023-08-18

Applicant: HOLTEC INTERNATIONAL

Inventor： Krishna P. Singh

IPC: G21F5/12

Abstract: A nuclear waste cask in one embodiment includes an axially elongated cask body defining a longitudinally-extending opening forming an entrance to an internal storage cavity of the cask configured for holding radioactive nuclear waste materials. A closure lid detachably coupled to the cask body at the top opening seals the cavity. A cask locking mechanism includes a plurality of first locking protrusions spaced apart on the lid which are selectively interlockable with a plurality of second locking protrusions spaced apart on the cask body to lock the lid to the cask body. The first locking protrusions may be disposed on slideable locking bars moveable between locked and unlocked positions while the lid remains stationary on the cask body. Hydraulic or pneumatic actuators may be used to change position of the locking bars. The cask and lid may include other features such as impact absorbers and lifting elements.

公开(公告)号：US12191045B2

公开(公告)日：2025-01-07

申请号：US17746599

申请日：2022-05-17

Applicant: HOLTEC INTERNATIONAL

Inventor： Krishna P. Singh ,  Stephen J. Agace

IPC: G21F5/10 ,  G21F5/008 ,  G21F5/12

Abstract: A passively cooled stackable nuclear waste storage system may include a pair of vertically stacked radiation-shielded nuclear waste storage casks. Each cask has a cavity which holds a nuclear waste canister containing spent nuclear fuel or other high-level radioactive wastes. The lower cask may be founded on an above-grade concrete pad. The upper cask is vertically stacked on and detachably coupled to the lower cask. The upper cask comprises a perforated baseplate which establishes fluid communication between cavities of both casks and is configured to prevent radiation shine. One or both casks may include air inlet vents configured to draw ambient ventilation air into each respective cask cavity for cooling the nuclear waste. In operation, air is drawn inward into each cask cavity independently. Air heated in the lower cask rises into the upper cask where it mixes with air drawn into the upper cask and is returned to atmosphere.

公开(公告)号：US12191042B2

公开(公告)日：2025-01-07

申请号：US17725969

申请日：2022-04-21

Applicant: HOLTEC INTERNATIONAL

Inventor： Krishna P. Singh

IPC: G21C19/40 ,  G21D9/00 ,  F24V99/00 ,  G21C19/07

Abstract: A system uses nuclear fuel decay heat to heat a building. The system includes a plurality of fluidly-isolated but thermally-coupled heat removal flow loops that operate in tandem to absorb thermal energy originating from water in a spent nuclear fuel pool located in the building. The thermal energy is transferred in a cascading manner from a first flow loop to a final flow loop which has an external heat sink located outside the building. The heat sink can transfer heat to an ambient environment. A controller regulates the intake and flowrate of cooling water into the final flow loop. The controller also monitors fuel pool water temperature and air temperature inside the building. The controller can regulate the flowrate to maintain a predetermined building air temperature by allowing the fuel pool water temperature to rise to near a maximum permissible limit.

公开(公告)号：US12080440B2

公开(公告)日：2024-09-03

申请号：US18109290

申请日：2023-02-14

Applicant: Holtec International

Inventor： Krishna P. Singh ,  Charles W. Bullard, II ,  Xuejun Zhai ,  John D. Griffiths

IPC: G21F5/12 ,  G21F5/012 ,  G21F5/08

CPC classification number: G21F5/12 ,  G21F5/012 ,  G21F5/08

Abstract: A nuclear waste cask with impact protection includes impact limiters comprising deformable energy-absorbing perforated sleeves. An impact amelioration system for nuclear fuel storage components includes impact limiter assemblies at the bottom cask to canister interface including impact limiter plugs frictionally engaging corresponding plug holes formed in the cask closure plate. A nuclear waste fuel storage system includes an unventilated cask including a heavy free-floating radiation shielding lid loosely coupled the top end of the cask in a movable manner via the anchor bosses which provides cask over pressurization protection. A nuclear waste cask includes an axially elongated rectangular cuboid cask body having a cavity for holding nuclear waste materials and cask locking mechanism including first locking protrusions on the lid which are selectively interlockable with mating second locking protrusions on the cask body to lock the lid to the cask body.

公开(公告)号：US20240087765A1

公开(公告)日：2024-03-14

申请号：US18465743

申请日：2023-09-12

Applicant: HOLTEC INTERNATIONAL

Inventor： Krishna P. SINGH

IPC: G21F5/12 ,  G21F5/008 ,  G21F5/08

CPC classification number: G21F5/12 ,  G21F5/008 ,  G21F5/08

Abstract: A system for transporting radioactive materials which may include a containment vessel, a thermal shield, and an impact limiter. The containment vessel may include a vessel body having a storage cavity for receiving radioactive materials, a lid coupled to an upper portion of the vessel body to enclose a top end of the storage cavity, and a lid seal such as a gasket positioned between the lid and the upper portion of the vessel body. The thermal shield may be positioned over the lid. The first impact limiter may be positioned over the thermal shield. The thermal shield may be resistant to high temperatures and may help to protect the integrity of the lid seal when the system is subjected to high temperatures, such as during a fire condition.

公开(公告)号：US20240068749A1

公开(公告)日：2024-02-29

申请号：US18374903

申请日：2023-09-29

Applicant: Holtec International

Inventor： Krishna P. SINGH ,  Joseph Gerald Leo RAJKUMAR ,  Vytautas Vincas MACIUNAS ,  Raghavendra PALLE ,  Debabrata MITRA-MAJUMDAR ,  Abrar Hasan MOHAMMAD ,  John D. GRIFFITHS

IPC: F28B1/06 ,  G21F5/12

CPC classification number: F28B1/06 ,  G21F5/12 ,  G21F5/008

Abstract: An air-cooled condenser system for steam condensing applications in a power plant Rankine cycle includes an air cooled condenser having a plurality of interconnected modular cooling cells. A method for forming an axial flow baffle for a shell and tube heat exchanger includes providing a baffle workpiece, locating a centerpoint of a first axial flow tube aperture, drilling flow holes around the centerpoint of the flow aperture, and drilling a central tube hole at the centerpoint. A method of cooling high level waste includes surrounding a cask comprising an external surface and an internal storage cavity containing the high level radioactive waste which emits heat with a cooling water header; and discharging cooling water radially inwards from the cooling water header onto the external surface of the cask from the plurality of water dispensing outlets arranged on the cooling water header.

公开(公告)号：US20230197304A1

公开(公告)日：2023-06-22

申请号：US18109290

申请日：2023-02-14

Applicant: Holtec International

Inventor： Krishna P. SINGH ,  Charles W. BULLARD, II ,  Xuejun ZHAI ,  John D. GRIFFITHS

IPC: G21F5/12 ,  G21F5/012 ,  G21F5/08

CPC classification number: G21F5/12 ,  G21F5/012 ,  G21F5/08

Abstract: A nuclear waste cask with impact protection includes impact limiters comprising deformable energy-absorbing perforated sleeves. An impact amelioration system for nuclear fuel storage components includes impact limiter assemblies at the bottom cask to canister interface including impact limiter plugs frictionally engaging corresponding plug holes formed in the cask closure plate. A nuclear waste fuel storage system includes an unventilated cask including a heavy free-floating radiation shielding lid loosely coupled the top end of the cask in a movable manner via the anchor bosses which provides cask over pressurization protection. A nuclear waste cask includes an axially elongated rectangular cuboid cask body having a cavity for holding nuclear waste materials and cask locking mechanism including first locking protrusions on the lid which are selectively interlockable with mating second locking protrusions on the cask body to lock the lid to the cask body.

公开(公告)号：US20230082771A1

公开(公告)日：2023-03-16

申请号：US17981978

申请日：2022-11-07

Applicant: Holtec International

Inventor： Krishna P. SINGH ,  Stephen J. AGACE ,  Stephen E. THOMPSON ,  John D. GRIFFITHS ,  Richard M. SPRINGMAN ,  Charles W. BULLARD, II ,  P. Stefan ANTON

IPC: G21C19/40 ,  G21C19/06

Abstract: A method of retrofitting a spent nuclear fuel system with a neutron absorbing apparatus. The method includes inserting a neutron absorbing apparatus into a first cell of an array of cells each configured to hold a spent nuclear fuel assembly. The neutron absorbing apparatus includes a first wall and a second wall supported by a corner spine to form a chevron shape and a first locking tab protruding outwardly from the first wall towards a first cell wall of the first cell. The method includes cutting a half-sheared second locking tab in the first cell wall of the first cell adjacent to and above the first locking tab of the neutron absorbing apparatus. Finally, the second locking tab is positioned to locking engage the first locking tab to retain the neutron absorbing apparatus in the first cell during removal of one of the fuel assemblies from the first cell.

公开(公告)号：US20230005635A1

公开(公告)日：2023-01-05

申请号：US17866797

申请日：2022-07-18

Applicant: Holtec International

Inventor： Krishna P. SINGH

IPC: G21F9/36 ,  B65D21/02

Abstract: An underground ventilated system for storing nuclear waste materials. The system includes a storage module having an outer shell defining an internal cavity and an inner shell. A majority of the height of the outer shell may be disposed below grade. The outer shell may include a hermetically sealed bottom. First and second canisters are positioned in lower and upper portions within the cavity respectively in vertically stacked relationship. A centering and spacing ring assembly is interspersed between the first and second canisters to transfer the weight of the upper second canister to the lower first canister. The assembly may include centering lugs which laterally restrain the first and second canisters in case of a seismic event. A natural convection driven ventilated air system cools the canisters to remove residual decay heat to the atmosphere. In one non-limiting embodiment, the shells are made of steel.

公开(公告)号：US20230005632A1

公开(公告)日：2023-01-05

申请号：US17868486

申请日：2022-07-19

Applicant: HOLTEC INTERNATIONAL

Inventor： Krishna P. SINGH ,  John D. GRIFFITHS

IPC: G21F5/12 ,  G21F5/012

Abstract: A radioactive nuclear waste storage system includes a cask comprising a hermetically sealed internal cavity configured for holding the waste such as spent nuclear fuel submerged in an inventory of water. One or more pressure surge capacitors disposed inside the cask include a vacuum cavity evacuated to sub-atmospheric conditions prior to storage of fuel in the cask. At least one rupture disk seals a vacuum chamber inside each capacitor. Each rupture disk is designed and constructed to burst at a predetermined burst pressure level occurring inside the cask external to the capacitor. This allows excess cask pressure occurring during a high pressure excursion resulting from abnormal operating conditions to bleed into capacitor, thereby returning the pressure inside the cask to acceptable levels. In one embodiment, the capacitors are located in peripheral regions of the cask cavity adjacent to the circumferential wall of the cask body.