David L Graves

US Patent:

54250706, Jun 13, 1995

Filed:

Jul 22, 1994

Appl. No.:

8/279039

Inventors:

James S. Gosnell - Orland Park IL
David C. Graves - Morris IL

Assignee:

Commonwealth Edison Company - Chicago IL

International Classification:

G21C 1900

US Classification:

376260

Abstract:

Apparatus for engaging and aligning lower ends of rodlets, or pins, of a nuclear fuel assembly insert. The apparatus facilitates positioning the insert within guide tubes of a nuclear fuel assembly. The nuclear fuel assembly insert rodlet alignment apparatus includes a mounting rack for attachment to a reactor or spent fuel pool edge, a first fixed plate attached to the mounting rack's lower end, and a second sliding plate attached to the first fixed plate. The first and second plates are respectively provided with first and second comb structures each comprised of elongated, linear, pointed teeth arranged in a spaced manner along an edge of a generally flat plate. The lower end of a crank, or rotating shaft, is coupled to the sliding plate by means of suitable linkage permitting the sliding plate to be moved on the fixed plate between a first position wherein the two comb structures are non-overlapping and a second position wherein the two comb structures overlap. The fuel insert pins are first inserted into the fixed plate comb structure, with the sliding plate comb structure then moved into overlapping position with the first comb structure such that each pin is engaged and securely maintained in fixed position by adjacent pairs of teeth of the first and second orthogonally aligned comb structures to prevent misalignment and entanglement of the lower ends of the pins. The fuel assembly insert may then be pulled up into a conventional handling tool with the pins still aligned.