Verfahren und Vorrichtung zur selbsttaetigen gegenseitigen Anpassung der Druecke eines fluessigen Moderators im Moderatortank eines gasgekuehlten Kernreaktors und eines den Reaktor durchstroemenden Kuehlgases

摘要

1,132,920. Reactors. SULZER BROS. Ltd. 14 Dec., 1967 [15 Dec., 1966], No. 56862/67. Heading G6C. In a gas-cooled liquid-moderated calandria type reactor means are provided to ensure that the pressure of the liquid is kept close to that of the gas so that thin-walled calandria tubes may be used. As shown, a moderator vessel 1 with tubes 3 containing fuel rods 2 is disposed within a concrete pressure vessel 5. The heated coolant gas, e.g. CO 2 , flows out of the tubes 3 into the interior of the vessel 5 and generates steam in a heat exchanger 6, the gas being returned to a chamber 4 by a blower 8. A connecting line 9 for the moderator, e.g. D 2 O, connects the vessel 1 to a balance tank 10 which also receives gas along a line 11 from the atmosphere surrounding the vessel. Flow smoothers 12, 13 having honeycomb cells (Fig. 2, not shown) to induce a large number of parallel flow paths act as buffer chambers to prevent reverse flow of the fluid. Further flow smoothers 14, 15 situated downstream of tap-off lines 16, 17 prevent moderator molecules which are diffusing from the liquid space into the gas space in the balance tank 10 passing into the coolant circuit and also prevent gas molecules dissolved from the gas space into the liquid space in the tank from passing into the moderator vessel 1. The quantity of fluid tapped-off through the lines 16, 17 is such that the flow speeds through the lines 11, 9 are greater than the speeds of diffusion of the moderator and coolant gas molecules, respectively. The coolant is returned to the pressure vessel 5 through a filter 20, separator 21, blower 22 and non-return valve 24. The moderator from line 17 reaches a reservoir 30 through a gas separator 27 and filter 29, the moderator being returned to the vessel 1 by a pump 31, valve 33 and non-return valve 34. In order to control the moderator pressure in relation to the coolant pressure so as to keep the pressure difference small, the valve 33 is controlled by a signal line 36 responsive to the moderator level in the tank 10 sensed by a detector 35. A cooling circuit 40 for the moderator includesa cooler 43 and a gas separator 41, the purified moderator being returned to the reservoir 30.