US3627632A
Expired / Lapsed
US
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Hydraulic drive for emergency shutdown of nuclear reactors
Assignee: Licentia Patent Verwaltungs GmbH
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Filing: 1968-11-25
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Granted: 1971-12-14
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Expires: 1988-11-25
Abstract
Abstract Hydraulic drive system for effecting the emergency shutdown by control rods of a nuclear reactor in which a guide housing is connected to the pressure vessel of the reactor. A control rod drive piston is movably mounted in a guide housing connected to the reactor. Such drive piston and guide housing together forming a drive chamber on one side of the drive piston and a counterpressure chamber on the other side thereof. The drive chamber is connected to a pressure medium chamber in the pressure vessel and to the counterpressure chamber such that, when the counterpressure chamber is opened to atmosphere, pressure medium flows from the pressure medium chamber into the drive chamber to move the drive piston; hence, the control rod connected thereto, rapidly into the emergency shutdown position.
Inventors
- 👤 Heinz Acher
- 👤 Eberhard Obenauf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:00
CPC Classifications
G; G21; G21C; G21C7/00; G21C7/06; G21C7/08; G21C7/12; G21C7/16; G21C9/00; G21C9/02; G21C9/027; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
207 words
Hydraulic drive system for effecting the emergency shutdown by control rods of a nuclear reactor having a pressure medium chamber in a reactor pressure vessel comprising, in combination: a. a guide housing connected to said pressure vessel; b. a drive piston mounted for movement in said guide housing, said drive piston and guide housing forming (1) a drive chamber on the pressure vessel side, (2) a counterpressure chamber on the opposite side of said drive piston, and (3) a connecting gap between said drive and counterpressure chambers; c. a neutron-absorbing portion of such control rods connected to said drive piston; d. means connected to the drive piston for making fine adjustments in the position of said neutron-absorbing portion; e. means for opening said counterpressure chamber to atmosphere during emergency shutdowns; f. a first conduit connecting said pressure medium chamber to said drive chamber; and g. a relief valve disposed in said first conduit which opens the same during emergency shutdowns to allow pressure medium to flow successively from said pressure medium chamber into said drive and counterpressure chambers when said counterpressure chamber is opened to atmosphere, as a consequence of which said drive piston and thereby said neutron-absorbing portion are moved rapidly into an emergency shutdown position.
Claim 2
Dependent Claim
207 words
Hydraulic drive system for effecting the emergency shutdown by control rods of a nuclear reactor having a pressure medium chamber in a reactor pressure vessel comprising, in combination: a. a guide housing connected to said pressure vessel; b. a drive piston mounted for movement in said guide housing, said drive piston and guide housing forming (1) a drive chamber on the pressure vessel side, (2) a counterpressure chamber on the opposite side of said drive piston, and (3) a connecting gap between said drive and counterpressure chambers; c. a neutron-absorbing portion of such control rods connected to said drive piston; d. means connected to the drive piston for making fine adjustments in the position of said neutron-absorbing portion; e. means for opening said counterpressure chamber to atmosphere during emergency shutdowns; f. a first conduit connecting said pressure medium chamber to said drive chamber; and g. a relief valve disposed in said first conduit which opens the same during emergency shutdowns to allow pressure medium to flow successively from said pressure medium chamber into said drive and counterpressure chambers when said counterpressure chamber is opened to atmosphere, as a consequence of which said drive piston and thereby said neutron-absorbing portion are moved rapidly into an emergency shutdown position.
Claim 3
Dependent Claim
32 words
Hydraulic drive system as defined in claim 1 wherein said means (e) includes a pressure-medium-controlled differential valve connected to said counterpressure chamber for opening the same to atmospheric pressure during emergency shutdowns.
Claim 4
Dependent Claim
23 words
Hydraulic drive system as defined in claim 2 further comprising a shutdown tank connected to said drive chamber and charged with pressure medium.
Claim 5
Dependent Claim
39 words
Hydraulic drive system as defined in claim 3 wherein said shutdown tank is connected to said drive chamber via a connecting line and said diFferential valve is connected to said connecting line to open the same during emergency shutdowns.
Claim 6
Dependent Claim
103 words
Hydraulic drive system as defined in claim 1 wherein a collector chamber is defined between said guide housing and said drive piston, said collector chamber being disposed beyond said drive chamber toward said reactor pressure vessel and being connected to the pressure medium chamber thereof, and said first conduit being connected to said pressure medium chamber via said collector chamber; and a cylindrical heat protection wall is located between said collector chamber and said guide housing, said heat protection wall being spaced from said guide housing to define a heat protection chamber therebetween which is filled with a pressure medium as a coolant.
Claim 7
Dependent Claim
58 words
Hydraulic drive system as defined in claim 5, further comprising means for feeding pressure medium taken from said counterpressure chamber into said collector chamber and wherein a second conduit connecting said collector chamber to said drive chamber is formed between said drive piston and guide housing, whereby pressure medium from said collector chamber flows into said drive chamber.
Claim 8
Dependent Claim
64 words
Hydraulic drive system as defined in claim 5 wherein said drive piston is hollow, the interior of said piston forming part of said counterpressure chamber and said drive piston being provided near its end toward said pressure medium chamber with a relief valve which connects said counterpressure chamber with said collector chamber when the drive chamber is charged with pressure from said shutdown tank.
Claim 9
Dependent Claim
43 words
Hydraulic drive system as defined in claim 7 wherein said piston relief valve includes an opening which is so arranged and dimensioned with respect to said guide housing that it is closed before completion of the emergency shutdown movement of said drive piston.
Claim 10
Dependent Claim
37 words
Hydraulic drive system as defined in claim 7 wherein the pressure medium is in the form of water which is fed into the collector chamber to a level which is always located above said piston relief valve.
Claim 11
Dependent Claim
36 words
Hydraulic drive system as defined in claim 9 wherein an opening for draining pressure medium from said collector chamber is provided near the end of said guide housing in the direction toward said pressure medium chamber.
Claim 12
Dependent Claim
56 words
Hydraulic drive system as defined in claim 1 wherein said drive piston is connected to said fine adjustment means via latch elements coupled to each other and further comprising means for decoupling said latch elements when there is excess pressure in said drive chamber, said decoupling means being operated by the pressure in said drive chamber.
Claim 13
Dependent Claim
97 words
Hydraulic drive system as defined in claim 11 wherein one of said latch elements is a pivotal lever one end of which is coupled to another latch element, and said decoupling means includes a piston disposed in said drive piston and having one end engaging the other end of said pivotal lever and its other end in communication with said drive chamber, as a consequence of which said decoupling piston is charged by pressures in said drive chamber to decouple said pivotal lever from the other latch member; hence said fine adjustment means from said drive piston.
Claim 14
Dependent Claim
61 words
Hydraulic drive system as defined in claim 1 wherein a closing element is provided on said drive piston and in said counterpressure chamber, said means (e) including a tube leading from said counterpressure chamber and said closing element being aligned with said tube for closing the same after said drive piston has been moved a certain distance during the emergency shutdown.
Claim 15
Dependent Claim
51 words
Hydraulic drive system as defined in claim 13, further comprising a pressure medium reservoir connected to said pressure medium chamber and pressurized thereby; and wherein a pump is connected to said counterpressure chamber via said tube for taking pressure medium therefrom, said pump being also connected to said pressure medium reservoir.
Claim 16
Dependent Claim
38 words
Hydraulic drive system as defined in claim 14, further comprising a drainage pump connected betwEen said collector chamber and said pressure medium reservoir, said drainage pump feeding pressure medium from the collector chamber into the pressure medium reservoir.
References Cited (Backward Citations)
US3031397A
Cited
US2975119A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-13 | 1975-06-14 | 1975-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-13 | 1979-06-14 | 1979-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-13 | 1983-06-14 | 1983-12-14 | $7700.00 | Window Closed / Lapsed |