John G Griffiths

US Patent:

47880210, Nov 29, 1988

Filed:

Oct 6, 1987

Appl. No.:

7/105656

Inventors:

John E. Griffiths - Morrisville PA

International Classification:

B29C 4700
B29C 5904

US Classification:

26417717

Abstract:

A method of fabricating a clamp cushion for use with a clamp device for mounting and restraining wires. Uncured resilient material is extruded through an extrusion die to form an extrusion having a raised upper surface on one side and, on the other side, a passageway being defined by longitudinal side walls and cover flaps to accommodate the clamp device. A toothed surface is then pressed into the raised surface of the extrusion to form a plurality of longitudinally spaced transverse nodes.

US Patent:

20220351872, Nov 3, 2022

Filed:

Jun 27, 2022

Appl. No.:

17/850213

Inventors:

- Camden NJ, US
John D. GRIFFITHS - Deptford NJ, US
Stephen J. AGACE - Middletown DE, US
Joseph A. MECKLEY - Marlton NJ, US

International Classification:

G21F 5/008
B23K 9/00
G21F 5/005
G21F 5/10
G21F 5/12
G21F 9/34
G21F 9/36

Abstract:

A container system for radioactive waste and method for using the same is provided. The system includes a canister configured for holding radioactive waste and a lid system. In one embodiment, the lid system comprises a two-part lid assembly including a confinement lid and a shielded lifting lid. The confinement lid is detachably mounted to the confinement lid. In use, the lifting lid supports the confinement lid for lifting and placement on the canister. The lifting lid further shields operators while the confinement lid is mounted to the canister. Thereafter, the lifting lid is removed and may be reused for confinement lid mountings on other canisters. In one embodiment, the confinement lid is bolted to the canister. The canister may be disposed in a protective overpack for transport and storage.

US Patent:

20230082771, Mar 16, 2023

Filed:

Nov 7, 2022

Appl. No.:

17/981978

Inventors:

- Camden NJ, US
Stephen J. AGACE - Voorhees NJ, US
Stephen E. THOMPSON - Bel Air MD, US
John D. GRIFFITHS - Deptford NJ, US
Richard M. SPRINGMAN - Drexel Hill PA, US
P. Stefan ANTON - Southampton NJ, US

International Classification:

G21C 19/40
G21C 19/06

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.

US Patent:

20230005632, Jan 5, 2023

Filed:

Jul 19, 2022

Appl. No.:

17/868486

Inventors:

- Camden NJ, US
John D. GRIFFITHS - Deptford NJ, US

Assignee:

HOLTEC INTERNATIONAL - Camden NJ

International Classification:

G21F 5/12
G21F 5/012

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.

US Patent:

20210343438, Nov 4, 2021

Filed:

Apr 1, 2021

Appl. No.:

17/220560

Inventors:

- Camden NJ, US
John D. GRIFFITHS - Deptford NJ, US

Assignee:

HOLTEC INTERNATIONAL - Camden NJ

International Classification:

G21F 5/12
G21F 5/012

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.

US Patent:

20210343439, Nov 4, 2021

Filed:

Jul 13, 2021

Appl. No.:

17/374005

Inventors:

- Camden NJ, US
Xuejun ZHAI - Mount Laurel NJ, US
John D. GRIFFITHS - Deptford NJ, US

International Classification:

G21F 5/12
G21F 5/08
G21F 5/012

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 overpressurization 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.

US Patent:

20210225537, Jul 22, 2021

Filed:

Nov 12, 2020

Appl. No.:

17/095834

Inventors:

- Camden NJ, US
Evan ROSENBAUM - Marlton NJ, US
John D. GRIFFITHS - Deptford NJ, US
Indresh RAMPALL - Cherry Hill NJ, US
Joseph Gerald Leo RAJKUMAR - Cherry Hill NJ, US

International Classification:

G21C 19/07
G21F 1/08

Abstract:

A neutron absorbing insert for use in a fuel rack. In one aspect, the insert includes: a plate structure having a first wall and a second wall that is non-coplanar to the first wall; the first and second walls being formed by a single panel of a metal matrix composite having neutron absorbing particulate reinforcement that is bent into the non-coplanar arrangement along a crease; and a plurality of spaced-apart holes formed into the single panel along the crease prior to bending.

US Patent:

20210225541, Jul 22, 2021

Filed:

Dec 23, 2020

Appl. No.:

17/132102

Inventors:

- Camden NJ, US
John D. GRIFFITHS - Deptford NJ, US

International Classification:

G21F 5/015
G21F 5/06
G21C 19/32
G21F 5/005

Abstract:

An impact amelioration system for nuclear fuel storage components in one embodiment includes a fuel storage canister and outer cask receiving the canister. The canister is configured for storing spent nuclear fuel or other high level radioactive waste. A plurality of impact limiter assemblies are disposed on the bottom closure plate of the cask at the canister interface. Each impact limiter assembly comprises an impact limiter plug frictionally engaged with a corresponding plug hole formed in the cask closure plate. The canister rests on tops of the plugs, which may protrude upwards beyond the top surface of the bottom closure lid. The plugs and holes may mating tapered and frictionally engaged surfaces. During a cask drop event, the canister drives the plugs deeper into the plug holes and elastoplastically deform to dissipate the kinetic impact energy and protect the structural integrity of the canister and its contents.