Patent Number: 
Section: claims

1. A nuclear reactor internals component having a sensor insert for monitoring one or more environmental conditions surrounding the sensor insert's location within a reactor internals, the nuclear reactor internals component comprising;a head;an elongated shank extending from the head to a distal end, the shank having a hollow compartment extending at least partially between the distal end and the head and a cross-sectional profile of the elongated shank being sized to fit into an opening in the reactor internals;an end plug for sealing off the hollow compartment at the distal end, affixed to the distal end;one or more self-contained, passive environmental sensors secured within the hollow compartment in the sensor insert; andan anchor for fixing the elongated shank in the opening in the reactor internals, the anchor including a locking mechanism that fixes an orientation of the shank within the opening in the reactor internals, wherein the locking mechanism is a lockbar that extends through an opening in the head and through a groove on a surface off the shank and partially into a groove in a surface of a wall in the opening in the reactor internals, in which the shank is to be inserted. 2. The nuclear reactor internals component of claim 1 wherein the one or more self-contained, passive environmental sensors comprise a plurality of environmental sensors respectively configured to monitor different environmental parameters. 3. The nuclear reactor internals component of claim 1 wherein the one or more environmental sensors comprise material samples, dosimetry or maximum temperature monitors. 4. The nuclear reactor internals component of claim 1 wherein the sensor insert includes one or more coded markings that identify the location of the sensor insert within the reactor internals. 5. The nuclear reactor internals component of claim 4 wherein the coded markings identify the orientation of the sensor insert within the reactor internals. 6. The nuclear reactor internals component of claim 1 wherein the anchor comprises one of either a male or female thread extending over at least a portion of the shank, that is sized to mate with another of a male or female thread on the opening in the reactor internals. 7. The nuclear reactor internals component of claim 1 wherein the lockbar is held in position within the opening in the head by a spring clip wedged against a portion of the head. 8. The nuclear reactor internals component of claim 7 wherein the spring clip is wedged in a counter-bore in a surface of the head. 9. The nuclear reactor internals component of claim 8 wherein the spring clip is a circular spring clip. 10. The nuclear reactor internals component of claim 1 wherein the shank has an axial dimension along an elongated dimension of the shank and the hollow compartment is partitioned into separate axial compartments in the sensor insert in which the one or more self-contained, passive environmental sensors are respectively supported. 11. The nuclear reactor internals component of claim 1 comprising a plurality of self-contained passive environmental sensors secured within the hollow compartment, wherein the hollow compartment is partitioned into separate circumferential compartments in the sensor insert in which the plurality of self-contained, passive environmental sensors are respectively supported. 12. The nuclear reactor internals component of claim 1 comprising a plurality of self-contained passive environmental sensors secured within the sensor insert within the hollow compartment, wherein the plurality of self-contained, passive environmental sensors are housed within the sensor insert comprising a partitioned sheath within which the plurality of self-contained, passive environmental sensors are separated, with the sheath sized to slide into and out of the hollow compartment. 13. The nuclear reactor internals component of claim 12 wherein the sheath has a positioning feature that fixes the orientation of the sheath relative to the hollow compartment. 14. The nuclear reactor internals component of claim 12 wherein the sheath has a coded marking that identifies the sensor insert in which it resided. 15. The nuclear reactor internals component of claim 12 wherein the sheath includes a gripping feature proximate the distal end to ease movement of the sheath out of the hollow compartment. 16. The nuclear reactor internals component of claim 1 wherein the one or more environmental sensors includes a neutron activation wire that is enclosed within a stainless steel tubing with cadmium shielding. 17. The nuclear reactor internals component of claim 1 wherein the shank comprises Stainless Steel 347 and/or titanium. 18. The nuclear reactor internals component of claim 1 wherein the distal end of the shank has a larger circumference than a portion of the shank that extends from the head. 19. The nuclear reactor internals component of claim 1 wherein the head has a flared circumferential extension configured to mechanically engage with a circumferentially-machined groove or slot in the opening in the reactor internals. 20. The nuclear reactor internals component of claim 1 wherein the reactor internals component is configured to resemble a bolt used elsewhere in the reactor internals. 21. The nuclear reactor internals component of claim 1 wherein the reactor internals component is configured to function as a thimble plug. 22. The nuclear reactor internals component of claim 1 wherein the reactor internals component has an external profile substantially equal to a profile of another reactor internals component.