The huge bill has been angrily attacked as "ludicrous" and "eye-watering" by Scottish politicians, who point out that the money could be used instead to build dozens of schools or hospitals. But the MoD insisted it represented "best possible value" for taxpayers.
The former UK defence minister, Philip Hammond, told MPs that a total of £13bn had been earmarked over the next decade for "maintaining the Trident strategic weapons system, including costs associated with the nuclear warhead". That amounts to 18% of the MoD's entire £72bn equipment support programme.
According to the Scottish National Party (SNP), about £1bn of the £13bn is due to come from taxpayers in Scotland if they remain part of the UK. That money could be used instead to build 125 new primary schools, or 20 new community hospitals, it says (see table below).
A further £1.6bn of the defence equipment budget had been allocated for "nuclear propulsion", Hammond said. This will include the costs of running the reactors that power the four Vanguard-class submarines that carry Trident missiles, as well as those that drive conventionally armed Astute submarines.
Critics point out that the new figures may not include all the costs associated with maintaining Trident, like sailors' wages or investments in the nuclear bomb factories at Aldermaston and Burghfield in Berkshire. They also don't include the estimated £100bn price tag for replacing the Trident system in the future.
"Scots pay a whopping £1bn just to keep Trident ticking over - weapons of mass destruction which the vast majority of Scots do not want," declared the SNP's Westminster leader and defence spokesman, Angus Robertson.
He added: "It is ludicrous that we are paying billions of pounds of taxpayers' money when it could and should be used to build a fairer society and stronger economy, with more opportunities for all."
The Green MSP, Patrick Harvie, warned that £1bn was the price that everyone in Scotland would pay for remaining part of the UK.
"Westminster wants to sign Scotland up for eye-watering bills over the coming decade just to maintain an immoral and illegal weapon of mass destruction on the Clyde," he said. "Instead, we could invest to transform our energy system, with clean green energy infrastructure owned by the community and generating profit for the public purse, helping us build a more equal and sustainable society."
Spending on Trident was also fiercely criticised by Kate Hudson, the general secretary of the Campaign for Nuclear Disarmament in London. "The exorbitance of simply running the current Trident system is breathtaking," she told the Sunday Herald.
"When the Government tells us that we need to tighten our belts as a country - that we can't afford vital NHS services, that crucial welfare for those in desperate need must be cut - one look at the spending on nuclear weapons is enough to blow that myth wide open."
She added: "We know what will really secure our future: sustainable energy, a working health service, quality education and investment in housing - not a redundant Cold War weapons system which even many in the military don't want."
The MoD, however, disagreed. "Our first duty is to defend the interests and citizens of the United Kingdom and our submarine-based continuous at-sea deterrent is the ultimate safeguard of our national security," said an MoD spokeswoman.
"No alternative would be as effective at deterring threats, which is why we are committed to maintaining a minimum credible nuclear deterrent at the best possible value for the taxpayer."