TORONTO (Reuters) - Investors in uranium miners stand to reap the rewards of a coming boom in nuclear power construction, but to win big they will have to be patient.

The nuclear renaissance is centered in Asia, where China plans to more than double nuclear power capacity by 2020.

At the same time, Russia says it will stop downblending weapons grade uranium from 2013, creating what some expect will be a 20 million-pound hole in an already tightening world supply.

Analysts say this gives plenty of upside potential to Canadian companies like Uranium One and Cameco Corp , one of the world's largest producers of the nuclear fuel.

"We're forecasting very significant deficits, mostly starting around 2012-2013, growing by 2020 to more than a 100 million-pound deficit," said RBC Capital Markets analyst Adam Schatzker. "That's huge."

"Our view is we're going to see a strong uptick in the uranium price towards the end of 2011, probably more into 2012. For a lot of (investors) that's just too long to wait."

Increased demand and higher uranium prices would be good news for Saskatchewan-based Cameco, which has already signed a deal to provide uranium for plants that China is building. It is expected to sign a similar deal with India, where nuclear power capacity is targeted to quadruple by 2020.

Cameco recently cut its sales outlook for 2010, as some customers deferred deliveries into 2011. But with its Cigar Lake mine set to begin initial production in 2013, the company looks poised to be back in the game at the right time.