How much does Trident cost?

Parliament is set to vote next week on whether or not to push ahead with the building of four submarines which will replace the existing Trident nuclear deterrent.

This is part of a process which has been ongoing since 2007 when the government, supported by a vote in parliament, began a programme to update and maintain the UK’s nuclear weapons beyond the early 2030s.

But how much will replacing Trident cost?

Replacing the current class of nuclear submarines is expected to cost £31 billion. Another £10 billion has been put aside to cover any extra costs or spending over the estimate.

So far in the development of the Trident replacement the government has allocated or spent around £4.8 billion of its budget.

That’s just for new submarines. There are several other costs linked to Trident.

Extending the life of the current Trident missiles into the early 2060s will cost around £250 million.

Keeping the current Trident submarines in operation until 2028, four years longer than planned, is also expected to cost between £1.2 and £1.4 billion. The House of Commons Library says that savings from the Submarine Enterprise Performance Programme are expected to make up for some of that.

Any other costs from a delay in introducing Trident will come out of the existing budget for its running costs.

What is the cost of running Trident day to day?

The Ministry of Defence’s budget for 2016/17 is a planned £35 billion, increasing every year to 2020/21 when it is estimated to be almost £40 billion.

The annual operating costs of Trident are expected to be around 5% to 6% of this every year, or around £2 billion. That’s about 1% of government spending on social security and tax credits in 2015/16, or the amount spent on the NHS every week.

How much has Trident cost in the past?

In 1998 the Strategic Defence Review estimated that the costs of buying Trident originally had been £12.52 billion. In 2015/2016 prices this is around £18.35 billion.

Once the system began to be used in 1994, it cost between 3% and 4.5% of the annual defence budget to run. It increased to between 5% and 6% in 2005-06 and has remained at this level ever since.

What would scrapping Trident cost?

The UK’s nuclear deterrent is controversial and some have suggested scaling it back or scrapping it altogether.

This would also cost money. The Ministry of Defence has estimated that nuclear decommissioning would cost around £4 billion over several years.

However, the House of Commons Library points out that these costs include decommissioning the Navy’s seven nuclear-powered submarines and it is unclear if this included the four submarines which carry ballistic missiles. It has been suggested that decommissioning the Trident submarines will be covered within the existing operating budget.

Although renewing Trident has been the policy of the current and all previous governments, a review was published in 2013 which looked at alternative options, assuming the UK keeps some form of deterrent. These options included moving Trident from submarines to ships or aircraft, using bombs instead of missiles, and only having the nuclear deterrent available at certain times, rather than now when it is constantly ready.

This review found that no alternative could be operational before 2035 at the earliest, and projected that 2040 was more likely. This would mean that to some extent the current Trident replacement plans would need to be continued until then if the UK were to keep its nuclear deterrent. The options considered in the review were also projected to cost anywhere from £20 to £30 billion, in current values, across their life span.