Remotely replaceable fuel assembly alignment pin
US5297176A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 1992 |
| Grant date | Mar 22, 1994 |
| Priority date | — |
| Expiry date | May 22, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E30/30
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
The guide pin aligning a top nozzle of a nuclear fuel assembly to an upper core plate of a nuclear reactor, is replaced working exclusively from below the upper core plate. The replacement guide pin has a shaft portion engaged with the upper core plate and the clamping nut which held the original guide pin, by threadable connection and/or by an expansion fitting. A shoulder on the pin bears against a lower surface of the upper core plate, and a nose of the pin is received in the top nozzle of the fuel assembly. A preferred expansion fitting has a bushing with ridges on its outer surface and a conical inside surface, and is inserted into the bored out original guide pin shaft. A threaded conical plug is pulled axially with rotation of the replacement pin shaft to expand the bushing. The ridges rigidly lock the replacement pin between the shoulder and the clamping nut. By attaching the replacement pin to the stub of the original pin, the invention utilizes existing attachments of the original pin to the upper core plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.