System and Process for Production and Collection of Radioisotopes

Patent metadata

Field	Value
Publication number	US-2018122521-A1
Application number	US-201615341478-A
Country	US
Kind code	A1
Filing date	Nov 2, 2016
Priority date	Nov 2, 2016
Publication date	May 3, 2018
Grant date	—

Abstract

A means for installing material, through a fuel assembly instrument thimble insert, into the existing instrument thimbles in nuclear fuel assemblies for the purpose of allowing the material to be converted to commercially valuable quantities of desired radioisotopes during reactor power operations during a remainder of a fuel cycle and removing the radioisotopes from the core through the reactor flange opening once the fuel assemblies have been removed for refueling. The invention also describes methods that can be used to harvest the irradiated material so it can be packaged for transportation from the reactor to a location where the desired radioisotope(s) can be extracted from the fuel assembly instrument thimble insert.

First claim

What is claimed is:

1 . A nuclear fuel assembly flux thimble insert comprising:
an elongated tubular housing having an axis along its elongated dimension, the elongated tubular housing being closed at a forward end and capped at a rearward end to form a target specimen chamber there between within an interior of the elongated tubular housing, the elongated tubular housing being sized to slide within an instrument thimble of a nuclear fuel assembly, with the rearward end structured to be driven by a drive cable of an existing moveable in-core detector system; and an elongated target specimen captured between a forward and a rear axial position plug wherein the axial position plugs are structured to seat against an interior wall of the elongated tubular housing to hold the target specimen at a preselected axial position within the interior of the elongated tubular housing.

2 . The nuclear fuel assembly flux thimble insert of claim 1 , wherein the target specimen is formed from one or more of Co-60, W-188, Ni-63, Bi-213 and Ac-225.

3 . The nuclear fuel assembly flux thimble insert of claim 1 , wherein the elongated tubular housing is constructed from a material having a low neutron capture cross-section.

4 . The nuclear fuel assembly flux thimble insert of claim 3 , wherein the elongated tubular housing is constructed from zirconium or a zirconium alloy.

5 . The nuclear fuel assembly flux thimble insert of claim 1 , wherein the axial position plugs maintain their axial position due to friction between interfacing surfaces on the axial position plugs and the interior wall of the elongated tubular housing.

6 . The nuclear fuel assembly flux thimble insert of claim 1 , wherein the axial position plugs maintain their axial position by fitting in slight recesses in the interior wall of the elongated tubular housing.

7 . The nuclear fuel assembly flux thimble insert of claim 6 , wherein the axial position plugs have an upper and lower surface that extends substantially orthogonal to the axis with an outer, substantially circular wall extending between the upper and lower surface, wherein the axial dimension of the outer, substantially circular wall is sized to fit in one of the recesses.

8 . The nuclear fuel assembly flux thimble insert of claim 7 , wherein the interface of the upper and lower surfaces with the outer, substantially circular wall are slanted at an acute angle to facilitate lodging and dislodging of the axial position plugs from the recesses.

9 . A method of irradiating an isotope that requires an extended exposure within a nuclear reactor lasting at least one fuel cycle, to achieve an intended target product, comprising the steps of:
enclosing the isotope within an elongated tubular housing having an axis along its elongated dimension, the elongated tubular housing being closed at a forward end and capped at a rearward end to form a target specimen chamber therebetween within an interior of the elongated tubular housing, the elongated tubular housing being sized to slide within an instrument thimble of a nuclear fuel assembly, with the rearward end structured to be driven by a drive cable of an existing moveable in-core detector system; positioning the isotope at a preselected axial position within the elongated tubular housing; attaching the rearward end to the drive cable; driving the isotope within the elongated tubular housing into and at least partially through an instrument thimble of a selected nuclear fuel assembly within a core of a nuclear reactor; leaving the isotope within the instrument thimble for the remainder of a fuel cycle of the core; withdrawing the elongated tubular housing from the core at the end of the fuel cycle; removing the selected fuel assembly from the core; reinserting the elongated tubular housing at least partially into the core; and removing at least a portion of the elongated tubular housing that contains the isotope by dislodging the portion from the drive cable.

10 . The method of claim 9 wherein the dislodging step cuts the elongated tubular housing around a circumference.

11 . The method of claim 10 including the step of transferring the portion under water to a spent fuel pool.

12 . The method of claim 11 transferring the portion in a building housing the spent fuel pool to a shielded package for shipment.

Assignees

• Westinghouse Electric Co Llc

Inventors

• Heibel Michael D

Classifications

• G21C23/00

  Adaptations of reactors to facilitate experimentation or irradiation · CPC title

• G21C17/108 Primary

  Measuring reactor flux · CPC title

• G21G1/02 Primary

  in nuclear reactors (by thermonuclear reactions G21B; conversion of nuclear fuel G21C) · CPC title

• G21C19/20 Primary

  Arrangements for introducing objects into the pressure vessel; Arrangements for handling objects within the pressure vessel; Arrangements for removing objects from the pressure vessel · CPC title

• G21C19/07

  Storage racks; Storage pools · CPC title