Radiation-induced palladium doping of metals to protect against stress corrosion cracking
US5602888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1995 |
| Grant date | Feb 11, 1997 |
| Priority date | — |
| Expiry date | Apr 5, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E30/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for mitigating crack growth on the surface of stainless steel or other alloy components in a water-cooled nuclear reactor wherein a solution or suspension of a compound containing a noble metal is injected into the coolant water while the reactor is not generating nuclear heat, e.g., during shutdown or recirculation pump heatup. During shutdown, the reactor coolant water reaches temperatures as low as 120.degree. F., in contrast to the water temperature of 550.degree. F. during normal operation. During pump heatup, the water temperature reaches 400.degree.-450.degree. F. At these reduced temperatures, the rate of thermal decomposition of the injected noble metal compound is reduced. However, radiation-induced decomposition also occurs inside the reactor. In particular, the noble metal compound can be decomposed by the gamma radiation emanating from the nuclear fuel core of the reactor. The noble metal compound decomposes under reactor thermal and radiation conditions to release ions/atoms of the noble metal which incorporate in or deposit on the oxide film formed on the stainless steel and other alloy components. As a result, the electrochemical potential of the metal surf…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.