There's a nuclear war coming. One in which it will be the smart who pile in and the foolish who stay on the sidelines. And one where the yields will be measured not in megatons, but in pounds sterling. Billions of them.

The opening rounds are already being fought and the big boys are already in play - the multinational construction companies, the global engineering groups and, if they too are smart, the law firms hungry for big deals to close.

Next month, the government will publish its White Paper on the future of the UK's energy supply. It is the worst-kept secret in Whitehall that top of the list will be proposals to renew the UK's commitment to nuclear power.

Battle lines between the pros and the antis are already being drawn, but according to Hamish Lal, partner in Scottish-based law firm Dundas & Wilson since last year, they are too late and on the wrong battlefield.

The argument is not just about being "greener" than thou. It is also about commercial sense, national security, and climate change. And it is an argument that has largely already been decided. Nuclear is not an industry waiting for this coming environmental debate to be settled. Its future is not in limbo somewhere over the horizon. It is here, now.

Lal is a barrister and D&W's expert on the nuclear industry. And he is leading the charge for this Scottish Big Four player in what promises to be one of the contract battles of the century.

Forget booting the door down to win work from constructors bidding for the 2012 London Olympics' contracts, says Lal. That entire deal is probably worth just £5bn.

Instead, think nuclear. The UK Nuclear Decommissioning Authority alone already has £64bn to throw around over the next 30 years or so. That is the entire Olympics' budget every year until 2040. And we have not started talking about any new reactor build programmes. Even the most hidebound senior partner can see where the percentage fees are going on that kind of money.

Lal, 37, has a law degree from Oxford, a PhD from Dundee and a civil engineering degree. His CV lists his specialisation as "contentious and non-contentious construction, engineering and project finance law". His weapon of choice is his expertise in the intricacies of NEC3 - the New Engineering Contract template the government is now applying to everything from offshore work and the Olympic construction contracts, to nuclear decommissioning. Lal said: "When you talk to the mandarins in Whitehall, they have decided: we need nuclear power.

"We need it for socio-economic reasons. In other words, cheap electricity. We need it for national security reasons. They do not want to wake up one morning and have Gazprom tell us their inter-connectors are empty. And we need it because it is carbon neutral and will help us meet our Kyoto agreements.

"In England, the debate has been settled. Scotland is now the battleground. Both SNP and Scottish Labour are anti-nuclear, so the industry must start to lobby now if Scotland is to reap the full benefit."

Benefits are already there. BNFL at Sellafield continues to process spent fuel from UK, French and Japanese reactors, and British Energy still runs reactors. In all there is about 2.3 million cubic metres of waste to be disposed of. That involves the construction of long-term settling ponds where the waste "cools" over decades. The ponds require roofs, and evaporators to process the contaminated atmosphere within.

Then there are the reactor decommissioning contracts. At present the UK has 19 reactors generating 20% of our electricity. Those reactors will be off grid by 2023.

Every major construction and engineering group in the world has divisions already bidding for all those contracts. And D&W's Lal is there to bid for the right to close them. It is a field in which he has a head start. He does not know of another Scottish firm with a nuclear specialist partner on board.

He will not be drawn on how much this might eventually be worth to D&W's bottom line, save to say the sky's the limit. And he has not started talking about the new reactor building programme that must inevitably follow.

Lal said: "There will be legal issues to be resolved first. Where? Let us say they will be built at existing sites, because the jobs, experience and infrastructure are already there. But British Energy own 65% of those sites and the other UK generators, the National Powers and the E.ONs and RWEs are likely to cry not fair!'. That will have to be resolved.

"The government say the planning process will be streamlined so that we are not waiting years for a decision. There will be issues there to be resolved. Then there will be the debate over who carries the decommissioning and the waste (financial) risks. The government has already said, it will not be us'. So who? And how?"

Lal's strategy is to accumulate experience in those processes so that when it actually comes to, say, British Energy saying, "we want a power station here', they're going to come to us to draw up the deal."

It is a bonanza that Scotland could well miss out on. An anti-nuclear Scottish Labour or SNP-controlled parliament would have devolved power over the planning process no matter what Westminster might say.

Yet Lal feels they are missing the point. Their objections are to Three Mile Island and Chernobyl-generation reactors: huge, vastly exorbitant to run, with radioactive legacies for generations to come. But technology moves on. The current designs are to those, as a 747 would be to the Wright Brothers' first effort. Together, their legacy is 2.3 million cubic metres of pretty "hot" waste. But 10 new generation reactors built now, would generate just 100,000 cubic metres of a far lower grade material in the course of their working lives, says Lal.

"I started neither pro nor anti," says Lal of the coming nuclear versus environment debate. "But we are a nuclear power. And you can't put the genie back in the bottle. If the question is how do we have cheap, clean, secure energy, what do you think the answer is?"

l Hamish Lal will address a seminar on the nuclear industry at D&W's office at Saltire Court, 20 Castle Terrace, Edinburgh on March 16, 2007.