After a long period of aphasia of nuclear investments due to political hurdles and strong reglementations, government from industrialised countries consider a new nuclear energy as a major political option for climate risks and long term security of supply. However, the liberalization of electricity markets adds a serious new constraint on this very capitalistic type of investment seen as specifically risky by financiers. The decentralized referential model appears particularly incompatible with this type of generation investment for competitive firms. However it evolves towards more favorable structures for investments. After having specified the particular constraints inherent to nuclear investment in market environment, the paper presents some potential adaptative ways to relaunch investments in nuclear going more or less radically far from the ideal model : long term electricity contracts, vertical and horizontal reintegration to manage volume-risk and price-risk, or the out of market setting of new nuclear productions through a purchasing obligation.