TECHNICAL FIELD

The present invention relates to a pump/heat exchanger assembly of a nuclear reactor, in particular a liquid metal cooled nuclear reactor.

In particular, the invention relates to a pump/heat exchanger assembly comprising a primary circulation pump, i.e. operating on a primary cooling fluid of the reactor, and a primary heat exchanger, where the primary fluid circulates and inside which the circulation pump of the primary fluid is housed.

The invention also relates to nuclear reactor, in particular a liquid metal cooled nuclear reactor, equipped with said pump/heat exchanger assembly, operating on the primary cooling fluid of the reactor.

STATE OF THE PRIOR ART

Italian Patent Applications Nos. MI2007A001685 (subsequently extended to International Patent Application WO2009/024854), MI2008A000766 (International Patent Application WO2009/040644) and GE2015A000036 (International Patent Application WO2016/147139) show a pump/heat exchanger assembly of this type, inside which the shaft and the pump impeller are housed.

Document U.S. Pat. No. 4,216,821 also shows a solution of this type.

Such a solution is extremely compact, but not without drawbacks, particularly in terms of primary flow distribution. Since the tube bundle feed is radial, the axial velocity of the primary fluid drops when passing from the bottom to top in the heat exchanger's feed area. This axial velocity drop corresponds to higher pressure and therefore an overpressure in the upper part of the heat exchanger with respect to the lower part.

SUBJECT OF THE INVENTION

One object of the present invention is to provide a pump/heat exchanger assembly for a nuclear reactor that allows overcoming the drawbacks of known solutions and has further safety advantages.

The invention therefore relates to a pump/heat exchanger assembly of a nuclear reactor as defined in appended claim1, as well as a nuclear reactor as defined in appended claim6.

Further characteristics of the invention are defined in the dependent claims.

Essentially, the invention is characterized by a specific geometry of the impeller shaft of the pump of the pump/heat exchanger assembly. In fact, according to the invention, the shaft of the impeller has an optimized axial profile so as to overcome the above-mentioned drawbacks of the known art.

