Panmure Gordon stays on the fence at Aveva as the situation in Japan deteriorates, but notes that any further weakness in the shares should create a buying opportunity.The developer of engineering data and design information technology systems has seen its share price fall around 8% in the last week as investors fret about the outlook for nuclear new build in the wake of the tragic events in Japan.However, the group's nuclear operations account for less than 5% of its revenue, around £7.4m, and its Japanese business in that sector is only equal to around £3m of that, according to the broker. "The globe is addicted to power", says analyst George O'Connor, who notes that for the medium term, nuclear build restrictions should get more stringent, fuelling demand for AvevaNet, the group's project lifecycle management system.The broker sticks with current estimates despite investors' Japanese concerns. The target price is 1,579p.