A £4bn project to help replace nuclear-armed Trident submarines on the Clyde has been branded as “unachievable” for the third year running by a UK government watchdog.
The Infrastructure and Projects Authority (IPA) has again given the manufacture of new reactors to power replacement submarines its lowest rating of “red” for 2023-24. There are “major issues” that do not seem to be “manageable or resolvable”, it said.
The IPA has badged eight other major UK nuclear weapons projects, with a combined overall cost of over £55bn, as “amber”. This means they are facing “significant issues” which require “management attention”.
These include building new facilities at the Faslane nuclear base, near Helensburgh, and dismantling nuclear submarines at Rosyth in Fife. The construction of the entire future nuclear-powered fleets of submarines – Astute, Dreadnought and Aukus – was also rated amber.
Campaigners attacked the UK nuclear weapons programme as “an unaffordable shambles” and a “disastrous money pit”. They have demanded its cancellation, and asked for the money saved to be spent on public services.
The Scottish National Party (SNP) accused the Ministry of Defence (MoD) of being “totally unable” to deliver a cost-effective replacement for Trident on time. The Scottish Greens said that public money shouldn’t be wasted on “deadly Cold War hangovers.”
The MoD insisted that the Dreadnought programme was “on track” for submarines to start entering service in the “early 2030s”. It was working to “improve delivery confidence”.
Rolls-Royce, which is making Dreadnought submarine reactors for the MoD, accepted that the work was “challenging”. But it said progress was “accelerating” and it was “confident” it could deliver in time.
The IPA’s latest report for 2023-24 was published in January 2025, six months late. It assessed the feasibility of 227 major government projects, including 44 run by the MoD with a total cost of £298bn.
Nine of the MoD projects were related to nuclear weapons and submarine programmes, with a total cost of at least £59bn. The one that was given a red rating was to construct reactors to be installed in four Trident-armed Dreadnought submarines to replace ageing Vanguard submarines at Faslane in the 2030s.
The project was also rated as red in 2022-23 and 2021-22, as The Ferret reported. According to the IPA, that means that “successful delivery of the project appears to be unachievable” and it may need its “overall viability reassessed”.
It said: “There are major issues with project definition, schedule, budget, quality and/or benefits delivery, which at this stage do not appear to be manageable or resolvable.”
The Dreadnought reactors, which are being built by Rolls-Royce in Derby, faced “ongoing challenges associated with achieving the required delivery date” in 2028, the IPA added. This was an “important milestone” for the UK’s policy of keeping at least one nuclear-armed submarine on patrol all the time, known as “continuous at sea deterrent”.
Among the eight other nuclear projects rated as amber, was a £1.9bn scheme to build new facilities at Faslane and nearby Coulport, on the Clyde, to support new submarines. Its rating was kept secret in 2022-23 and it was red in 2021-22.
Amber is defined by the IPA as: “successful delivery appears feasible but significant issues already exist, requiring management attention”. The issues “appear resolvable at this stage” and should not cause delay or increased costs “if addressed promptly”.
The Clyde infrastructure project was entering its “most complex phase” over the next four years, the IPA said. It highlighted “two main issues affecting delivery confidence”.
One was rebuilding existing facilities while they continue to be used for submarine operations. The other was attracting and retaining suitably skilled staff “to a remote site in a very tight labour market in western Scotland.”
Costs of some nuclear projects kept secret
A £362m project to begin dismantling defunct nuclear submarines at the Rosyth naval base on the Firth of Forth, was also rated as amber for 2023-24, as it was for 2022-23 and 2021-22. “This is a novel and complex project and learning by doing encounters difficulty and challenge that cannot necessarily be planned for,” commented the IPA.
A £37bn project to build the four Dreadnought submarines, other than the reactors, has been rated as amber for the last six years. An £11bn project to finish building seven nuclear-powered but conventionally-armed Astute submarines has been amber for the last three years.
A new submarine programme, known as Aukus, to eventually replace the Astute-class boats, is under development with the US and Australia. Its budget for 2023-24 was £495m, but its total cost and delivery date have been kept secret to protect “national security” and “international relations”.
Aukus was rated as amber for 2023-24 and 2022-23. The IPA suggested that the MoD might be over-stretching itself on the project.
There was “a degree of risk relating to the ability of the defence nuclear enterprise and the wider UK supply chain to resource the programme with the necessary skills, experience and infrastructure to deliver against a demanding schedule, without adversely impacting the delivery of the Dreadnought programme,” it said.
A new programme repackaging previous projects for making and storing nuclear materials at Aldermaston in Berkshire has been rated as amber for the last two years. Its total cost and delivery date have been kept under wraps.
The rating, costs and comments on another project to test nuclear weapons in France and England, known as Teutates, have also been kept secret for national security and international relations reasons.
The SNP highlighted the MoD’s record of radioactive leaks and rising costs on the Clyde. “It is disappointing but not surprising that the MoD seems to be totally unable to manufacture a replacement for Trident in a timely or cost-effective manner,” said SNP MSP Keith Brown.
“The UK’s nuclear weapons aren’t safe for workers and wildlife, they don’t work when tested, and their manufacture is not efficient. Nor are they delivering a good deal for taxpayers.”
The Scottish Greens described nuclear weapons as a “moral abomination” that should be opposed. “The fact that they have also proven to be a disastrous money pit only underlines the urgent need to remove them for good,” said Green MSP Maggie Chapman.
“We could do so much good with this money, investing in services that make our lives safer and better, rather than wasting it on these deadly Cold War hangovers.”
The Scottish Campaign for Nuclear Disarmament (SCND) blasted the UK’s nuclear weapons as “a colonial hangover, an unaffordable shambles, a danger to us and the world”.
SCND chair, Lynn Jamieson, said: “The combined cost of keeping the nuclear weapon system going and of building a replacement escalates while public services are drastically cut.”
The Nuclear Information Service, which researches and criticises nuclear weapons, argued that the UK nuclear programme was unsustainable. “The case for cancelling badly run and unaffordable weapons projects is compelling,” said research manager, Tim Street.
Trident remains ‘formidable’
According to the Ministry of Defence, the Clyde nuclear bases were “at the forefront” of delivering a continuous at sea deterrent. Some of the new infrastructure had already been built, and a review in April 2024 had resulted in “positive steps and recommendations outlined to further support the pace of delivery.”
An MoD spokesperson said: “The UK’s deterrent remains effective, dependable, and formidable. The Dreadnought programme remains on track for the first of class, HMS Dreadnought, to enter service in the early 2030s.”
The MoD was “working closely with Rolls-Royce Submarines to improve delivery confidence, including by increasing production rates and improving manufacturing resilience”. The delays in building reactors were “not expected to directly delay” the delivery of submarine programmes.
In January 2025, the MoD announced a new £9bn, eight-year deal with Rolls-Royce to “deliver the design, manufacture and support services to nuclear reactors to power our submarines”.
Rolls-Royce Submarines stressed that it was a “highly complex” and “once in a generation” project. “We’re working closely with the MoD to ensure this important project faces no further delays,” a company spokesperson told The Ferret.
“The findings of the IPA report are being addressed and improvements have been recognised by the review team since the previous report. While the programme remains challenging, progress has accelerated and the majority of the technical and infrastructure challenges are now behind us.
“We remain confident in our ability to deliver to the required core delivery date for Dreadnought.”
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Cover image of Trident submarine on the Clyde thanks to the Ministry of Defence.
