Method and apparatus for locating a defective tube of a liquid metal-to-water tube type heat exchanger

A method of detecting the location of a tube leak position in a liquid-metal-to-water tube type heat exchanger having a plurality of tubes wherein liquid metal contacts one surface of said tubes and water contacts the other surface of said tubes, and wherein mingling of said liquid metal and water forms a reaction product, comprising:

• a. draining both the liquid metal and water from said heat exchanger;
• b. introducing helium to the outer surface of said tubes;
• c. introducing argon to the inner surface of said tubes, wherein the pressure on the inner surface of said tubes is less than or equal to the pressure on the outer surface of said tubes;
• d. heating the tubes to a temperature at which said reaction product breaks down, whereby the inert gas and reaction product mixture goes into the inner surface of said tubes wherever a leak in the tube wall occurs and the liquid metal and water mingle to form the reaction product;
• e. isolating the chemical content of the interior of each of said tubes;
• and
• f. analyzing said chemical content.

Apparatus for heating from the inner surface the tubes in a liquid metal-to-water tube type heat exchanger having a plurality of tubes wherein liquid metal contacts one surface of said tubes and water contacts the other surface of said tubes, said apparatus comprising:

• a. a nonconductive core;
• b. a resistance wire wound about said nonconductive core;
• c. power leads connected to said resistance wire;
• d. a flexible casing surrounding said power leads;
• e. an electric power source connected to said power leads;
• f. a first heat insulating surface below said core;
• g. a second heat insulating surface above said core, said second heat insulating surface containing an aperture coextensive with said flexible casing;
• and
• h. means connecting said first and second heat insulating surfaces.

A method of detecting the location of a tube leak position of a bayonet tube in a liquid metal-to-water detachable heat exchanger with an upper tube sheet and a lower tube sheet, wherein liquid metal passes through the interior of a first plurality of tubes, supported by one of said upper and lower tube sheets, water passes through the interior of a second plurality of tubes supported by the other of said tube sheets, and an interstitial medium transfers heat between said first plurality of tubes and said second plurality of tubes, comprising the steps of:

• a. draining the interior of said first plurality and said second plurality of tubes;
• b. removing said upper tube sheet and affixed tubes to expose said tubes;
• c. locally heating each of said tubes from the exterior so as to vaporize any trace elements at a leak location;
• d. removing said vaporized trace elements from the immediate tube location;
• and
• e. detecting said trace elements.

Apparatus for sealing, heating, and removing trace elements from the tube walls of a bayonet tube in a liquid metal-to-water detachable heat exchanger comprising:

• a. a tubular member, said tubular member being at least as long as said tube;
• b. a sealing member affixed to one extremity of said tubular member;
• c. a resistance coil within said sealing member;
• d. an end fitting, said end fitting comprising an electrical passage and a suction line passage;
• e. electrical leads within said tubular member from said resistance coil to said electrical passage;
• f. means to provide electrical power to said electrical leads;
• and
• g. means to pull a suction on the interior of said tubular member.