Patent US5454739A successfully refreshed from Google Patents.
Patent US4775508A successfully refreshed from Google Patents.
US4775508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zirconium alloy fuel cladding resistant to PCI crack propagation
Assignee: Westinghouse Electric Co LLC
•
Filing: 1987-12-08
•
Granted: 1988-10-04
•
Expires: 2007-12-08
Abstract
Abstract This invention relates to a tubular water reactor fuel cladding having an outer cylindrical layer composed of a conventional zirconium base alloy. Bonded to the outer layer is a second, inner layer composed of an alloy consisting essentially of: about 0.1 to 0.3 wt. % tin; about 0.05 to 0.2 wt. % iron; about 0.05 to 0.4 wt. % niobium; about 0.03 to 0.1 wt. % of either chromium or nickel, alone or in combination with each other; while keeping the sum of the iron chromium and nickel contents below 0.25 wt. %; 300 to 1200 ppm oxygen; and the balance essentially zirconium. The inner layer is characterized by excellent resistance to PCI crack propagation, excellent aqueous corrosion resistance and a fully recrystallized microstructure.
Inventors
- 👤 George P. Sabol
- 👤 Samuel G. McDonald III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:47
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/02; G21C3/04; G21C3/06; G21C3/07; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
144 words
A corrosion and crack resistant water reactor fuel cladding tube comprising: an outer cylindrical layer of a first zirconium alloy selected from the group consisting of Zircaloy-2 and Zircaloy-4; an inner cylindrical layer of a second zirconium alloy consisting essentially of: about 0.1-0.3 wt.% tin, about 0.05 to 0.2 wt.% iron, about 0.05 to 0.4 wt.% niobium, about 0.03 to 0.1 wt.% of an element selected from the group consisting of nickel, chromium and their combinations together, wherein the sum of the iron plus nickel plus chromium contents is less than 0.25 wt.%; less than 2000 ppm total impurities; 30- 700ppm oxygen; and zirconium forming essentially the balance; said inner cylindrical layer metallurgically bonded to said outer layer; and whereby said inner cylindrical layer has an aqueous corrosion resistance which is at least substantially equivalent to the corrosion resistance of said outer cylindrical layer.
Claim 2
Dependent Claim
144 words
A corrosion and crack resistant water reactor fuel cladding tube comprising: an outer cylindrical layer of a first zirconium alloy selected from the group consisting of Zircaloy-2 and Zircaloy-4; an inner cylindrical layer of a second zirconium alloy consisting essentially of: about 0.1-0.3 wt.% tin, about 0.05 to 0.2 wt.% iron, about 0.05 to 0.4 wt.% niobium, about 0.03 to 0.1 wt.% of an element selected from the group consisting of nickel, chromium and their combinations together, wherein the sum of the iron plus nickel plus chromium contents is less than 0.25 wt.%; less than 2000 ppm total impurities; 30- 700ppm oxygen; and zirconium forming essentially the balance; said inner cylindrical layer metallurgically bonded to said outer layer; and whereby said inner cylindrical layer has an aqueous corrosion resistance which is at least substantially equivalent to the corrosion resistance of said outer cylindrical layer.
Claim 3
Dependent Claim
30 words
The water reactor fuel cladding tube according to claim 1 wherein said second zirconium alloy has nickel content of 0.03-0.1 wt.% and a chromium content of less than 200 ppm.
Claim 4
Dependent Claim
33 words
The water reactor fuel cladding tube according to claim 1 wherein said second zirconium alloy has a chromium content of 0.03 to -0.1 wt.%, and a nickel content of less than 70 ppm.
Claim 5
Dependent Claim
24 words
The water reactor fuel cladding tube according to claim 1 wherein said second zironium alloy has a niobium content of 0.05 to 0.2 wt.%.
Claim 6
Dependent Claim
46 words
The water reactor fuel cladding tube according to claim 1 having a weight gain of less than 200 mg/dm 2 and an essentially black, adherent oxide film on said inner and said outer layers after 24 hours exposure to a 500° C. 1500 psi steam test.
Claim 7
Dependent Claim
20 words
The water reactor fuel cladding tube according to claim 1 wherein said inner cylindrical layer has a fully recrystallized microstructure.
References Cited (Backward Citations)
US3243350A
Cited
US3148055A
Cited
US3271205A
Cited
US3271265A
Cited
US3620691A
Cited
DE1589458A1
Cited
US4212686A
Cited
GB2104711A
Cited
DE3310054A1
Cited
CA1198231A
Cited
GB2119559A
Cited
JPS5958389A
Cited
EP0121204A1
Cited
US4610842A
Cited
JPS6036640A
Cited
US4664881A
Cited
US4675153A
Cited
US4735768A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-04 | 1992-04-04 | 1992-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-04 | 1996-04-04 | 1996-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-04 | 2000-04-04 | 2000-10-04 | $7700.00 | Window Closed / Lapsed |