Patent Number: 
Section: description

Using the drawings, the preferred embodiments of the present invention will now be explained. FIG. 1 shows an ICI assembly 16 (compressed flexible hose 10 is removed for clarity) that is used to measure conditions such as the power level and temperature of a nuclear reactor while the reactor is in operation. The assembly 16 includes a bullet nose 17 with a rounded tip. The hard metallic bullet nose 17 is relatively narrowed compared with the rearward components of the assembly 16. The shape and size of the bullet nose 17 aids in guiding the assembly 16 through the tortuous bend guide paths found in many reactors. As shown in FIG. 5, a central tensile member 20 is at one end connected to the bullet nose 17, and extends into a central bore of the bullet nose 17. At the opposite end of the central tensile member 20 is a seal plug 18, to which the central tensile member 20 is connected.. A plurality of detectors 21 is disposed around the periphery of the central tensile member 20. The detectors 21 are shown in FIG. 5 according to the present invention. Each of the detectors 21 includes a signal wire and an emitter. The signal wire and emitter can be insulated using an insulation material such as Al2O3, and housed within a sheath made of a metallic material. If the detectors 21 are subjected to the liquid and the high-pressure environment inside the nuclear reactor, the detector sheath may become pitted and cracked. The sheath is especially vulnerable while it is being directed through the interior of the nuclear reactor to detect conditions within the reactor. If water penetrates a detector wall, that detector will fail. A flexible outer hose 10 is provided to protect the detectors 21 and other nuclear applications within the ICI assembly from the harsh environment of the nuclear reactor during reactor operation. The hose 10 is pressure tight and, has properties that ensure that the interior of the hose is dry. Specifically, the starting sheath material that makes up the hose is a flexible bellows type hose 10 shown in, FIGS. 2 and 2a, where FIG. 2a is a close-up view. The hose 10 is made of a watertight material, and is provided with corrugations or ribs that impart flexibility to the hose 10. Each rib has a peak 11 with sides 12, on either side of the peak 1l, that each lead to a valley 13. The ends 14, 15 of the hose 10 will normally be attached to the ICI assembly 16 using a welding process, or other process that will provide a hermetic seal. Before the hose 10 is subjected to a collapse process, the sides 12 of the ribs are spaced apart from each other, and FIG. 1 represents the hose in its pre-collapsed form prior to being attached to the ICI assembly. FIGS. 3 and 3a show the hose 10 after it has been collapsed and is ready to be attached to the ICI assembly 16. The hose. 10 is collapsed using a hydro-collapse process that begins by placing the hose 10 in a hydro test fixture (not shown). A rod (not shown) is fitted to the inside of the hose. The rod is uniform in diameter, and extends along at least the entire length of the hose 10 to ensure that the hose 10 will collapse over its full length in a uniform manner during the hydro-collapse process. The rod is then sealed to one end of the hydro test fixture. Hydro-pressure is then applied to the hose 10 in the hydro test fixture, and the hose 10 collapses to the degree shown in FIG. 2, while the rod traverses outside the hydro test fixture. In its collapsed state, the hose 10 no longer has spaced apart ribs. The sides 12 of the ribs are no longer at an inclining angle relative to one another, and instead are in contact with one another. The peaks also are disposed substantially adjacent to one another and together form an outer diameter of the hose 10. The portions of the inner surface of the hose 10 that formed the valleys 13 also are disposed substantially adjacent to one another and together form the inner diameter of the hose 10. In a preferred embodiment of the invention, a commercially available flexible bellows hose 10 of the type shown in FIGS. 2 and 2a initially had a maximum outer diameter of 0.3.90 inches, measured from the peaks 11 of the ribs. The minimum inner diameter, measured from the inner surface of the hose 10 at the innermost portion of the valleys, was measured at 0.250 inches. The hose 10 was subjected to a series of applications of heat and pressure, where the pressure application was preformed using the above-described hydro test fixture process. After repeating the heat and pressure applications two times, the hose 10 was measured again. The hose 10 was measured to be less than half its starting length. The maximum outer diameter, again measured from the peaks of the ribs, was 0.418 inches. The minimum innermost diameter, measured from the portions of the inner surface of the hose 10 that formed the valleys, was 0.235 inches. Following the hydro-collapsing process, the hose 10 was hermetically sealed to the ICI assembly by, for example, a welding process. FIG. 4 shows the ICI assembly with the hose 10 of the present invention attached thereto. One end 14 of the hose 10 is attached to the bullet nose 17, while the opposite end 15 of the hose 10 is attached to the surface 19 of the seal plug 18 that is connected to the central tensile member 20. Accordingly, an airtight and watertight protection is provided to the detectors 21 by the hose 10 that surrounds the detectors 21 and the central tensile member 20. FIG. 5 shows a cross section of the front portion of the ICI assembly, showing the relationship between the hose 10, the central tensile member 20, the detectors 21, and the bullet nose 17. The preceding description has been presented only to illustrate and describe the invention. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. Many modifications and variations are possible in light of the above teaching. The preferred embodiment was chosen and described in order to best explain the principles of the invention and its practical application. The preceding description is intended to enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims.