Patent Number: 
Section: claims

1. An in-core instrument assembly used on a nuclear reactor, which comprises: a first member having a first end and a second end;  at least one detector;  a bullet nose having an outer peripheral surface and connected to the first end of the first member, wherein the first end of the first member extends over a portion of the peripheral outer surface;  a second member connected to the second end of the first member and having a seal plug with a surface; and  a flexible hose comprising:  a first end, hermetically sealed to the bullet nose of the first member;  a second end, hermetically sealed to the surface of the seal plug of the second member; and  a body portion extending from the first end to the second end of the hose that surrounds the at least one detector, and has flexible, corrugated outer and inner surfaces. 2. An in-core instrument assembly according to  claim 1 , wherein said body portion includes a series of ribs comprising peaks substantially adjacent to one another. claim 1 3. An in-core instrument assembly according to  claim 2 , wherein said ribs further comprise side surfaces that decline from said peaks to valley portions that are disposed between said side surfaces and are completely in physical contact with one another. claim 2 4. An in-core instrument assembly according to  claim 1 , wherein said hermetically sealed first and second ends of said hose provide an airtight and watertight enclosure for said at least one detector. claim 1 5. An in-core instrument assembly according to  claim 1 , wherein said hose is made of a non-corrosive metal. claim 1 6. An in-core instrument assembly according to  claim 1 , wherein said non-corrosive metal is stainless steel. claim 1 7. The in-core instrument assembly of  claim 1  wherein said body portion includes a plurality of ribs that extend over a portion of the peripheral outer surface of the bullet nose. claim 1 8. The in-core instrument assembly of  claim 7  wherein said plurality of ribs extending over the portion of the peripheral outer surface of the bullet nose are in contact with one another. claim 7 9. The in-core instrument assembly of  claim 1  wherein the first end of the flexible hose is hermetically sealed to the bullet nose by a weld. claim 1