Patent Number: 
Section: claims

1. A method of irradiating an isotope in a commercial nuclear reactor that has a moveable in-core detector system including detectors that travel in retractable thimbles that extend from a seal table, outside the nuclear reactor, up into a pressure vessel of the nuclear reactor and through instrument thimbles within fuel assemblies supported within a reactor core, the moveable in-core detector system further including a multi-path selector, positioned on an upstream side of the seal table, that selects the retractable thimbles through which the detectors travel, the method comprising the steps of:providing an elongated, hollow, target specimen cable sized to travel in one of the retractable thimbles with the target specimen cable being sealed at a lead end and having a removable plug that is configured to fit into a trailing end, the target specimen cable having a length sufficient to extend out of the seal table when the target specimen is fully inserted in a preselected, substantially fully extended retractable thimble;loading one or more target specimens through the trailing end into a forward location in the hollow of the target specimen cable;closing off the trailing end with the removable plug;identifying the preselected retractable thimble that extends into the instrument thimble into which the target specimen cable is to be loaded;inserting the lead end of the target specimen cable into the preselected retractable thimble;driving the target specimen cable through the retractable thimble and into the instrument thimble to an elevation that places the target specimen at a predetermined elevation;irradiating the target specimen at the predetermined elevation for a preselected period of time; andwithdrawing the target specimen cable from the instrument thimble after the preselected period of time and out of the preselected retractable thimble to a processing area where it can be loaded into a shielded transportation cask. 2. The method of claim 1 wherein the driving step is performed manually. 3. The method of claim 2 wherein the withdrawing step is performed manually. 4. The method of claim 1 wherein the inserting step is performed downstream of the multi-path selector and upstream of the seal table. 5. The method of claim 1 wherein the driving step comprises inserting the target specimen cable through the retractable thimble into the instrument thimble until the lead end of the target specimen cable reaches the sealed end of the retractable thimble causes the inserting step to cease, then withdrawing the target specimen cable to an axial elevation that places the target specimen at the predetermined elevation. 6. The method of claim 1 including the steps of partitioning the target specimen cable into different axial compartments and loading different target specimens in at least some of the compartments. 7. A method of irradiating an isotope in a commercial nuclear reactor that has a moveable in-core detector system including detectors that travel in retractable thimbles that extend from a seal table, outside the nuclear reactor, up into a pressure vessel of the nuclear reactor and through instrument thimbles within fuel assemblies supported within a reactor core, the moveable in-core detector system further including a multi-path selector, positioned on an upstream side of the seal table, that selects the retractable thimbles through which the detectors travel, the method comprising the steps of:providing an elongated, hollow, target specimen cable sized to travel in one of the retractable thimbles with the target specimen cable being sealed at a lead end and having a removable plug that is configured to fit into a trailing end, the target specimen cable having a length sufficient to extend out of the seal table when the target specimen is fully inserted in a preselected, substantially fully extended retractable thimble;loading one or more target specimens through the trailing end into a forward location in the hollow of the target specimen cable;closing off the trailing end with the removable plug;identifying the preselected retractable thimble that extends into the instrument thimble into which the target specimen cable is to be loaded;inserting the lead end of the target specimen cable into the preselected retractable thimble;driving the target specimen cable through the retractable thimble and into the instrument thimble to an elevation that places the target specimen at a predetermined elevation;sealing an outside of the target specimen cable to the seal table with a compression fitting to lock the target specimen cable in place;irradiating the target specimen at the predetermined elevation for a preselected period of time; andwithdrawing the target specimen cable from the instrument thimble after the preselected period of time and out of the preselected retractable thimble to a processing area where it can be loaded into a shielded transportation cask. 8. The method of claim 7 including the step of removing any excess material from the target specimen cable that extends approximately more than three inches above the compression fitting. 9. The method of claim 8 including the step of inserting the removable plug into the trailing end of the target specimen cable. 10. The method of claim 8 wherein the withdrawing step includes the steps of: releasing the compression fitting; attaching temporary tubing to the preselected retractable thimble above the seal table; and extending the temporary tubing to a staging area where the target specimen cable can be offloaded. 11. The method of claim 10 including the steps of: winding the target specimen cable that is offloaded into a coiled specimen cable; and loading the coiled target specimen cable into a transportation cask. 12. The method of claim 11 wherein the step of winding the target specimen cable includes the step of winding the target specimen cable around a spindle; and cutting the target specimen cable in segments. 13. The method of claim 12 wherein separate segments are wound around different spindles.