Use of shape memory alloys in fuel pellet holddown springs
US5317612A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 1992 |
| Grant date | May 31, 1994 |
| Priority date | — |
| Expiry date | Sep 25, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E30/30
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A composite holddown spring for applying an axial force to a fuel pellet stack in a nuclear reactor fuel rod. The composite holddown spring comprises a shape-memory alloy spring portion and a conventional metal spring portion. The shape-memory alloy spring portion has a two-way memory characteristic such that it contracts to a low temperature configuration at ambient temperatures wherein the axial force exerted by the shape-memory alloy spring portion is minimized and expands to a high temperature configuration at operating conditions wherein the axial force exerted by the shape-memory alloy spring portion is maximized. Somewhat conversely, the conventional metal spring portion weakens and contracts at operating temperature and strengthens and expands at atmospheric temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.