Scottish and Southern Energy, one of the UK's biggest power companies has withdrawn from its nuclear joint venture NuGen.The announcement comes after signals the company's interest in nuclear was waning at the end of last year when it said in its six month statement: 'The cost, development issues, timetable and operational efficacy of nuclear power stations all require the greatest possible scrutiny before a commitment to invest can be made'. SSE, as it makes clear, saw the joint venture with GDF Suez and Iberdrola - as a "toe in the water" exercise and its partners have now bought out its 25% stake.The plan had been to develop a new nuclear power station near Sellafield in West Cumbria but the final decision on whether to go ahead with the project must be made by 2015. As SSE's statement makes clear however: "even getting to the point of that decision will absorb, from now on, significant financial and management resources from everyone in the joint venture."SSE now says it is to focus investment on "renewable energy, gas-fired generation, including carbon capture and storage options, and alternative energy developments." SSE says that in these areas it has "knowledge and experience" but no experience of ownership in the nuclear sector.Shares in SSE were up 0.7% in early trading.BS