Patent GB-1414823-A (GB)
Title: Nuclear power plant
IPC: G21D5/08
Filed: 1973-05-23
Abstract: 1414823 Nuclear power plant E I GRISHANIN V G ILJUNIN I A KUZNETSOV V M MUROGOV and A N SHMELEV 23 May 1973 24682/73 Heading G6C In nuclear power plant comprising a steam power generating apparatus and two nuclear reactors the cooling circuits of which are arranged to effect heat transfer to the working medium of a turbine, one of the reactors is a fast fission breeder with a relatively low outlet temperature and the other has a relatively high outlet temperature. In a first embodiment (Fig. 1, not shown) the fast breeder reactor (1) gives up heat in a heatexchanger (3) to the coolant at the inlet side of another reactor (2) in series with the generating plant (6). The fast reactor uses liquid sodium or lithium as coolant and comprises metal fuel. The other reactor (2) may be a fast reactor or a steam-cooled thermal reactor using ceramic fuel. In a second embodiment (Fig. 2, not shown) the heat of the fast reactor (1) is given up in a heatexchanger (3) and the heat of another reactor (2) is given up in a heat-exchanger (7) in series with the first, to heat the working medium of the generating plant (6). The fast reactor (1) is sodium-cooled and the other reactor (2) may be a thermal reactor cooled by gas or steam, or may be a fast reactor cooled by sodium or a gas, e.g. CO 2  or He. If both are fast reactors, the first (1) uses an alloy of uranium and plutonium while the second (2) uses ceramic fuel. The working medium is vapourized in the first heat-exchanger (3) and superheated in the second (7). In a third embodiment (Fig. 3, not shown) the fast reactor (1) is divided into sub-zones (9, 10) with different outlet temperatures, the separate circuits (11, 12) being connected to respective heat-exchangers (13, 14) in series. The lower outlet temperature zone (9) uses metal fuel and the higher (10) uses ceramic fuel. The heatexchangers (13, 14) are in series with a further heat-exchanger (7) in the coolant circuit of the second reactor (2) and provide, respectively, economizer heating, vapourization and superheating of the generating plant working medium. The second reactor (2) may be a gas-graphite reactor and the fast reactor (1) may be gas- or sodium-cooled. The core of the fast reactor (1) may comprise plutonium, or uranium-235 or 233 and thorium, while the thermal reactor (r) may comprise uranium and thorium in a graphite matrix. The coolant in the fast reactor (1) may be helium when that in the thermal reactor (r) is carbon dioxide. In a fourth embodiment (Fig. 4, not shown) both reactors (1, 2) are gas-cooled and connected in a common loop (15) to the heat-exchanger (16) for heating the working medium of the generating plant (6). The fifth embodiment (Fig. 5, not shown) both reactors (1, 2) are gas-cooled and connected in a common cooling loop (15) in series with two heat-exchangers (7, 14) for heating the working medium of the generating plant (6), and the fast reactor (1) also supplies a further heat-exchanger (13) in parallel with the lower temperature heatexchanger (14) of the two others which perform superheating and evaporation/economizer functions, respectively. In another embodiment (Fig. 9, not shown) a gas-cooled fast reactor (1) is disposed inside a cavity (27) in a gas-cooled thermal reactor (2) within a housing (30). If the coolant pressure of the fast reactor (1) is higher than that of the thermal reactor (2), the former is disposed within a high-pressure shell in the housing (30). Coolant from the fast reactor (1) flows to a bottom collection plenum (29) and thence part flows through the thermal reactor (2), a first heat-exchanger (7) and blowers (28) while another part flows directly through a second heat-exchanger (3) and the gas blowers (28) from whence all the coolant is returned to the fast reactor (1). The heat-exchangers (7, 3) respectively perform superheating and evaporator/economizer functioning. In other embodiments (Figs. 6-8, not shown) one or more turbines (18, 26) is included in a closed, direct cycle circuit with the reactors (1,2) in series.