US3841757A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of distinguishing between fuel and/or breeder elements intended for or inserted in a nuclear reactor
Assignee: Forschungszentrum Jülich
•
Filing: 1972-11-24
•
Granted: 1974-10-15
•
Expires: 1992-11-24
Abstract
Abstract A method of distinguishing between fuel and/or breeder elements intended for or inserted in a nuclear reactor, the fuel and/or breeder materials being contained in a graphite covering or matrix. Before the fuel and/or breeder elements are introduced into the reactor, chemical substances are added to the carbon of the covering or matrix. After oxidizing, these chemical substances are slightly diffusible and at most negligibly affect the neutron flow of the reactor; their spectral lines are undisturbed by the carbon bands and are capable of being excited by a laser pulse. The chemical substances are introduced into the graphite of the covering or matrix at such a concentration, that the macroscopic neutron absorption cross section remains small. The fuel and/or breeder elements are irradiated by laser pulses in such a way, that the plasma focus formed thereby is located in the optical beam path of a device known per se and suitable for spectrum analysis.
Inventors
- 👤 T Overhoff
- 👤 H Stupp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:07
CPC Classifications
G; G21; G21C; G21C17/00; G21C17/06; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
133 words
A method of characteristically distinguishing between fUel elements intended for use in a nuclear reactor, said fuel elements being held in a graphite covering, which includes the steps of: introducing into the graphite of said covering chemical substances which are only slightly diffusible and at most negligibly affect the neutron flow of the reactor, the spectral lines of said chemical substances being undisturbed by the carbon bands and capable of being excited by a laser pulse, said chemical substances being introduced into said graphite at such a concentration that the macroscopic neutron absorption cross section remains small; and irradiating said fuel elements intended for use in said reactor with laser pulses so as to form a plasma focus and locating the same in the optical beam path of a suitable spectrum analysis device.
Claim 2
Independent Claim
133 words
A method of characteristically distinguishing between fUel elements intended for use in a nuclear reactor, said fuel elements being held in a graphite covering, which includes the steps of: introducing into the graphite of said covering chemical substances which are only slightly diffusible and at most negligibly affect the neutron flow of the reactor, the spectral lines of said chemical substances being undisturbed by the carbon bands and capable of being excited by a laser pulse, said chemical substances being introduced into said graphite at such a concentration that the macroscopic neutron absorption cross section remains small; and irradiating said fuel elements intended for use in said reactor with laser pulses so as to form a plasma focus and locating the same in the optical beam path of a suitable spectrum analysis device.
Claim 3
Dependent Claim
24 words
A method according to claim 1, in which said chemical substances are selected from the group consisting of thermally stable oxides and oxide-forming substances.
Claim 4
Dependent Claim
26 words
A method according to claim 1, in which said chemical substances are selected from the group of elements consisting of beryllium, aluminum, titanium, yttrium, and zirconium.
Claim 5
Dependent Claim
54 words
A method according to claim 3, in which said chemical substances are added to the material of said covering as solutions selected from the group consisting of carbonates, nitrates, and acetates under a hydrostatic pressure, and are converted to the oxide by means of subsequent decomposition at temperatures between approximately 200* and 400* C.
Claim 6
Dependent Claim
23 words
A method according to claim 1, in which said chemical substances are added to said graphite of said covering before compression and carburization.
Claim 7
Dependent Claim
38 words
A method according to claim 1, in which said chemical substances are added to said graphite of said covering at least by the time the introduction of said fuel elements intended for use in said reactor is complete.
Claim 8
Dependent Claim
22 words
A method according to claim 1, in which the concentration of said chemical substances added to said graphite is not over 50ppm.
Claim 9
Dependent Claim
47 words
A method according to claim 1, in which the intensity of the radiation of said plasma formed by means of said irradiation with laser pulses is increased by introducing said fuel elements intended for use in said reactor into an atmosphere of inert gas under high pressure.
Claim 10
Dependent Claim
25 words
A method according to claim 8, in which said inert gas under high pressure is helium under a pressure of at least 10 atmospheres absolute.
Claim 11
Dependent Claim
30 words
A method according to claim 1, in which the plasma in said focus is postheated by spikes formed with the laser in unspoiled condition at intervals measured in Mu sec.
Claim 12
Dependent Claim
29 words
A method according to claim 1, in which a plurality of said chemical elements are added, all combinations of said added chemical substances being used for said spectroscopic analysis.
Claim 13
Independent Claim
133 words
A method of characteristically distinguishing between breeder elements intended for use in a nuclear reactor, said breeder elements being held in a graphite covering, which includes the steps of: introducing into the graphite of said covering chemical substances which are only slightly diffusible and at most negligibly affect the neutron flow of the reactor, the spectral lines of said chemical substances being undisturbed by the carbon bands and capable of being excited by a laser pulse, said chemical substances being introduced into said graphite at such a concentration that the macroscopic neutron absorption cross section remains small; and irradiating said breeder elements intended for use in said reactor with laser pulses so as to form a plasma focus and locating the same in the optical beam path of a suitable spectrum analysis device.
Claim 14
Independent Claim
133 words
A method of characteristically distinguishing between breeder elements intended for use in a nuclear reactor, said breeder elements being held in a graphite covering, which includes the steps of: introducing into the graphite of said covering chemical substances which are only slightly diffusible and at most negligibly affect the neutron flow of the reactor, the spectral lines of said chemical substances being undisturbed by the carbon bands and capable of being excited by a laser pulse, said chemical substances being introduced into said graphite at such a concentration that the macroscopic neutron absorption cross section remains small; and irradiating said breeder elements intended for use in said reactor with laser pulses so as to form a plasma focus and locating the same in the optical beam path of a suitable spectrum analysis device.
Claim 15
Independent Claim
149 words
A method of characteristically distinguishing between a combination of fuel elements and breeder elements intended for use in a nuclear reactor, said combination of fuel elements and breeder elements being held in a graphite covering, which includes the steps of: introducing into the graphite of said covering chemical substances which are only slightly diffusible aNd at most negligibly affect the neutron flow of the reactor, the spectral lines of said chemical substances being undisturbed by the carbon bands and capable of being excited by a laser pulse, said chemical substances being introduced into said graphite at such a concentration that the macroscopic neutron absorption cross section remains small; and irradiating said combination of fuel elements and breeder elements intended for use in said reactor with laser pulses so as to form a plasma focus and locating the same in the optical beam path of a suitable spectrum analysis device.
Claim 16
Independent Claim
149 words
A method of characteristically distinguishing between a combination of fuel elements and breeder elements intended for use in a nuclear reactor, said combination of fuel elements and breeder elements being held in a graphite covering, which includes the steps of: introducing into the graphite of said covering chemical substances which are only slightly diffusible aNd at most negligibly affect the neutron flow of the reactor, the spectral lines of said chemical substances being undisturbed by the carbon bands and capable of being excited by a laser pulse, said chemical substances being introduced into said graphite at such a concentration that the macroscopic neutron absorption cross section remains small; and irradiating said combination of fuel elements and breeder elements intended for use in said reactor with laser pulses so as to form a plasma focus and locating the same in the optical beam path of a suitable spectrum analysis device.
References Cited (Backward Citations)
US3463591A
Cited
US3413481A
Cited
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 |