US3842238A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of sealing nuclear fuel elements by electric welding
Assignee: Westinghouse Electric Corp
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Filing: 1970-12-08
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Granted: 1974-10-15
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Expires: 1990-12-08
Abstract
Abstract A nuclear-fuel assembly has an end plug and is sealed except for a small diameter axial bore in the plug. A welding electrode of the same material as the plug has an end ground to a point. The tapered end is then inserted into the bore. Before the bore is sealed the assembly is filled with an inert-gas at high pressure. An electric welding current is then directed through the electrode and the plug to seal the bore.
Inventors
- 👤 E Boyko
- 👤 J Campbell
- 👤 R Wiggins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:16
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/02; G21C3/04; G21C3/06; G21C3/10; B; B23; B23K; B23K28/00; B23K28/02; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
182 words
The method of constructing a pressurized nuclear fuel unit in which a predetermined quantity of nuclear fuel is inserted into a thin-wall elongated metal tube, said tube having a metal plug sealing one end of the metal tube and another metal plug having an axial opening sealing the other end of the metal tube to form a container having electroconductive walls, the axial opening constituting the only communicative path between the interior and exterior of the container and in which at least the metal plug having the axial opening is disposed within a sealed chamber which is thereafter pressurized with an inert gas to establish a predetermined pressure within the container, the improvement of steps comprising, positioning a fusible welding electrode within the axial opening to make essentially line contact with the wall of the end plug having said axial opening, directing sufficient electrical current through said electrode, line contact and end plug to fuse the electrode by resistance heating, and continuing said fusion of the electrode by arc discharge welding until the axial opening is closed sealing the container under pressure.
Claim 2
Independent Claim
182 words
The method of constructing a pressurized nuclear fuel unit in which a predetermined quantity of nuclear fuel is inserted into a thin-wall elongated metal tube, said tube having a metal plug sealing one end of the metal tube and another metal plug having an axial opening sealing the other end of the metal tube to form a container having electroconductive walls, the axial opening constituting the only communicative path between the interior and exterior of the container and in which at least the metal plug having the axial opening is disposed within a sealed chamber which is thereafter pressurized with an inert gas to establish a predetermined pressure within the container, the improvement of steps comprising, positioning a fusible welding electrode within the axial opening to make essentially line contact with the wall of the end plug having said axial opening, directing sufficient electrical current through said electrode, line contact and end plug to fuse the electrode by resistance heating, and continuing said fusion of the electrode by arc discharge welding until the axial opening is closed sealing the container under pressure.
Claim 3
Dependent Claim
39 words
In the method of claim 1 wherein said electrode has a cross-section larger than the cross-section of the opening, and including the step of tapering the end of the electrode to enter said opening and establish said line contact.
Claim 4
Independent Claim
177 words
The method of constructing a pressurized nuclear fuel unit in which a predetermined quantity of nuclear fuel is inserted into a thin-wall elongated metal tube, said tube having a metal plug sealing one end of the metal tube and another metal plug having an axial opening sealing the other end of the metal tube to form a container having electroconductive walls, the axial opening constituting the only communicative path between the interior and exterior of the container and in which at least the metal plug having the axial opening is disposed within a sealed chamber which is thereafter pressurized with an inert gas to establish a predetermined pressure within the container, the improvement of steps comprising, positioning a fusible welding electrode with its tip within the opening but spaced from the wall of the opening to establish a gap therebetween and directing sufficient electrical current between the electrode and the wall to cause an arc to fuse the elEctrode tip and to weld the fused part of the electrode tip to the wall for sealing the opening.
Claim 5
Independent Claim
177 words
The method of constructing a pressurized nuclear fuel unit in which a predetermined quantity of nuclear fuel is inserted into a thin-wall elongated metal tube, said tube having a metal plug sealing one end of the metal tube and another metal plug having an axial opening sealing the other end of the metal tube to form a container having electroconductive walls, the axial opening constituting the only communicative path between the interior and exterior of the container and in which at least the metal plug having the axial opening is disposed within a sealed chamber which is thereafter pressurized with an inert gas to establish a predetermined pressure within the container, the improvement of steps comprising, positioning a fusible welding electrode with its tip within the opening but spaced from the wall of the opening to establish a gap therebetween and directing sufficient electrical current between the electrode and the wall to cause an arc to fuse the elEctrode tip and to weld the fused part of the electrode tip to the wall for sealing the opening.
Claim 6
Dependent Claim
31 words
The method of claim 3 wherein said opening has a predetermined cross section within which the tip of the electrode is positioned and a smaller cross section spaced from the electrode.
Claim 7
Dependent Claim
50 words
The method of claim 3 wherein the portion of the opening surrounding said tip has a cross section larger than the cross section of the tip and a portion of the opening beyond the end of the tip has a cross section smaller than the cross section of the tip.
Claim 8
Dependent Claim
32 words
In the method of claim 3, the step of shaping the end of the electrode to provide a blunt taper of the order of a cone having a vortex angle of 90*.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |