Abstract:  Chinese government expects to invest aggressively in overseas nuclear power (NP) as an important focus of the Belt and Road Initiative. However, there is a decision-making dilemma to seize the emergent market and face the high risk of investment. After more than 30 years of efforts, China has finally grasped the 3rd generations of NP technology with independent intellectual property rights, and has the ability to dominate the overall overseas NP projects. The State Council attaches great importance to the strategy of NP-going-out and calls for it to be translated into concrete actions as soon as possible. However, NP enterprises need to seize key going-out opportunities, and the failure rate of investment at the wrong time is as high as 80%. Traditional investment decision-making methods are not suitable for NP, and the error between predicted value and actual value is large. It is necessary to develop reliable analysis tools for accurately grasping the investment opportunities on emergent market & technology of NP.
After the emergence of the 3rd generations of NP technology, the uncertainty of the industrial competitive environment and the abundance of industrial profits are significantly higher; the international competition in NP market is also more intense, and France, Russia et. are exploring overseas markets. With the development of the Belt and Road Initiative, the opportunity window is getting bigger and bigger for China. The opening and closing of the window of opportunity is affected by both technology and market. It is the greatest challenge for investment management to grasp the opportunities faced with emerging technologies and markets. There is a great difference between NP investment and large-scale products. Traditional cost, sales and other significant factors are not significant for NP investment. Complex technological behavior accompanies the whole process of NP construction and maintenance, and significantly affects the opening of the opportunity window. The first adopters of new nuclear technology can occupy the market by technological monopoly and obtain excess profits, which will attract many countries to follow. NP project belongs to complex product system, it shows the herding effect of innovation imitation is weak, the cost of forerunner’ technology advantage is low, and the profit maintenance stage is long for investors. So，it is an important investors’ opportunity window at the leading stage. It is used to abstract the complex process of nuclear technology diffusion via Bass model. The largest cumulative installed capacity of NP market represents the market potential of the third generation of new NP technology, and the innovation coefficient represents the degree of influence of the third generation NP market in China, such as France, Russia and other developed countries; the imitation coefficient represents the influence of the host country’s market behavior by our country or has already adopted the third generation NP technology country’s influence degree.
Analyzing the diffusion characteristics of NP technology and the hypothesis of classical Bass model, found that there is a good fit between them. The maximum possible cumulative installed capacity of the international NP market, indicating the market potential of the third generation of new nuclear technology; innovation coefficient represents the extent to which the market behavior of the third generation of NP in China, HRP1000, is affected by other technologies from France and Russia and so on; imitation coefficient represents the extent to which the market behavior of the host country is affected by HRP1000 or other third generation NP technology. In the model, the ratio of accumulative installed units to potential users at t-time, represents the diffusion speed of the third generation NP technology at t time ; then the time when the technology-diffusion speed is the greatest, is called inflection point or critical point, which is regarded as the termination time of decision-making for the adoption of new technologies, and the stage from adoption to termination is the window of opportunity. NP "going out" is essentially a kind of commercial export behavior. Through the construction of FOAK(first of a kind), it is proved that the new technology can greatly improve efficiency and reduce costs, attract many countries to develop NP to join the ranks of imitators. The process of NP technology diffusion is a "learning- Digestion -adoption" process. Found by fitting the diffusion characteristics of NP technology with the classical Bass model, the larger of the technological innovation coefficient the smaller the width of the opportunity window, conversely the larger the imitation coefficient the greater of the opportunity window. The knowledge attribute of the third generation of NP technology in China is very obvious, and difficult to change to public knowledge. So, the transformation cycle is very long. By the Bass model of NP technology diffusion, we use the time series indices of single power unit of NP plant describe the diffusion speed of NP technology. By iterating the income curve and the cost curve, it is found that the best time to enter the opportunity window is not the same time as the best time to return, and the best time is always after the peak value of the income curve.
Though Fukushima Nuclear Accident has a significant impact on safety technology, the best time for overseas investment in NP is bound to be more delayed than the peak value of market earnings forecast. China’s overseas investment opportunities in NP is not mature,so they should strengthen the construction of cooperative networks with the host country, and wait for the best time to enter.

Key words: overseas investment in nuclear power, technology-diffusion, opportunity window and best time, Bass model