Method and Apparatus for Planting and Harvesting Radioisotopes on a Mass Production Basis

Patent metadata

Field	Value
Publication number	US-2019108921-A1
Application number	US-201715729745-A
Country	US
Kind code	A1
Filing date	Oct 11, 2017
Priority date	Oct 11, 2017
Publication date	Apr 11, 2019
Grant date	—

Abstract

A method and apparatus for modifying an existing nuclear reactor moveable in-core detector system to insert and withdraw target specimens from a reactor core during reactor operation without practically impeding the moveable in-core detector system's ability to obtain flux maps of the core throughout the reactor's operation. The apparatus provides a separate drive unit and delivery cable that is independent of the detector drive system, but uses most of the same core delivery conduits to access the core. A specimen holder is remotely detachable from the delivery cable when appropriately positioned and can be remotely reattached for withdrawal after a scheduled period of radiation.

First claim

What is claimed is:

1 . An irradiation target handling system having an isotope production cable assembly comprising:
a target holder drive cable constructed to be compatible with conduits of an existing nuclear reactor moveable in-core detector system that convey in-core detectors from a detector drive unit to and through instrument thimbles within a reactor core, the target holder drive cable having a remotely controlled one of a male or female coupling on a leading end of the drive cable; a target holder drive cable drive motor unit separate from and independent of the detector drive unit on the existing nuclear reactor moveable in-core detector system and configured to drive the target holder drive cable into and out of the core, wherein the target holder drive cable drive motor unit is structured to drive the target holder drive cable into and through the conduits, a first multipath selector and a second multipath selector on the existing nuclear reactor moveable in-core detector system; a specimen target holder having another of the male or female coupling on a trailing end of the specimen target holder with the another of the male or female coupling configured to mate with the one of the male or female coupling on the leading end of the target holder drive cable; and a third multipath selector structured to receive an input from an outlet path on the second multipath selector and provide a first output to a new specimen attachment location, a second output to an irradiated specimen offloading location and a third output to the core.

2 . The irradiation target handling system of claim 1 wherein the specimen target holder has a radial projection extending from or through an outside wall of the specimen target holder into contact with an interior wall of an instrument thimble in the reactor core, into which the specimen target holder is driven by the target holder drive cable, which maintains an axial position of the specimen holder within the instrument thimble, when the specimen holder is detached from the drive cable.

3 . The irradiation target handling system of claim 2 wherein the one of the male or female coupling is configured to move the radial projection away from the interior wall of the instrument thimble when coupled to the another of the male or female coupling on the specimen target holder.

4 . The irradiation target handling system of claim 1 including an axial positioning device attached to the specimen target holder for determining when the specimen target holder achieves a preselected axial position within an instrument thimble within the core, which the specimen target holder is driven into by the drive cable.

5 . The irradiation target handling system of claim 4 wherein the instrument thimbles have a closed upper end and a leading end of the specimen target holder has an axial projection that is sized to contact an interior of the closed upper end of the instrument thimble into which the specimen target holder is driven.

6 . The irradiation target handling system of claim 5 wherein the length of the axial projection is a wire having an adjustable length.

7 . The irradiation target handling system of claim 1 wherein the target holder drive cable enters the conduits through a “Y” connection with one leg of the “Y” connected to the target holder drive cable drive motor unit and a second leg of the “Y” connected to the detector drive unit.

8 . A method of irradiating multiple specimens within a core of a nuclear reactor that has a moveable in-core, radiation detector flux mapping system, wherein the core comprises a plurality of fuel assemblies respectively having instrument thimbles into which a radiation detector of the flux mapping system can be inserted and travel through, comprising the steps of:
inserting a first specimen holder containing a first specimen at a lead end of a first drive cable driven by a first drive unit, into a first instrument thimble in the core; remotely detaching the first drive cable from the first specimen holder and fixing an axial position of the first specimen holder within the first instrument thimble; withdrawing the first drive cable from the reactor; attaching a second specimen holder containing a second specimen to the lead end of the first drive cable driven by the first drive unit; inserting the second specimen holder containing the second specimen into a second instrument thimble in the core; remotely detaching the first drive cable from the second specimen holder and fixing an axial position of the second specimen holder within the second instrument thimble; withdrawing the first drive cable from the reactor; in between the withdrawing step and the second inserting step inserting a moveable in-core radiation detector from the moveable in-core detector radiation flux mapping system, attached to a second drive cable driven by a second drive unit, into and through a third instrument thimble; and withdrawing the moveable in-core radiation detector from the reactor after performing a flux mapping exercise.

9 . The method of claim 8 wherein the inserting steps insert specimen holders into as many as half the instrument thimbles accessible by the flux mapping system for simultaneous irradiation at a time when a flux map is to be conducted.

10 . The method of claim 8 wherein the steps of fixing the axial position of the specimen holders within the respective instrument thimbles includes the steps of determining when the respective specimen holders are at a preselected axial position within the corresponding instrument thimbles.

11 . The method of claim 8 wherein the step of withdrawing the first drive cable from the reactor comprises withdrawing the first drive cable out of the moveable in-core, radiation detector flux mapping system prior to the running of a flux map.

Assignees

• Westinghouse Electric Co Llc

Inventors

• Heibel Michael D
• Czerniak Luke D
• Heagy Melissa M
• Carvajal Jorge V
• Mcardle Matthew D
• Taylor Jeffrey J
• Yankel James L

Classifications

• G21C23/00 Primary

  Adaptations of reactors to facilitate experimentation or irradiation · CPC title

• G21G1/02

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

• G21C17/108 Primary

  Measuring reactor flux · CPC title

• G21G1/10 Primary

  by bombardment with electrically charged particles (irradiation devices G21K5/00) · CPC title

• G21G1/001

  Recovery of specific isotopes from irradiated targets · CPC title