The economic value of a new nuclear power station is determined by non-technical factors. If frivolous legal challenges are allowed to delay construction then new power stations will not be built. If excessive radiation protection standards are mandated then new power stations will not be operated. If schools fail to teach math and physics at a high enough level then new power stations will not be staffed. Factors such as these are controlled by the UK government. Therefore, the UK government can make new nuclear power stations worthwhile. In fact, they have an obligation to do so since the UK government is expected to protect the well being of the citizens.
Nuclear power stations produce inexpensive electricity, as shown in many studies from all over the world. These studies have not even considered improvements that could be made to further reduce costs. For example, the turbine exhaust from today's reactors is vented out into the environment. It could be sold to heat buildings, reducing the cost of the generated electricity even further.
There is a widespread misunderstanding that nuclear reactors can only be used for baseload power. In fact, CANDU reactors in Ontario have demonstrated that power output can be quickly adjusted between 60% and 100% of full power, and the reactor can continue running at any of these levels for extended periods. These adjustments are automated and can take place in real time in response to changes happening on the grid. Many of the constraints affecting the time needed for these changes are due to the turbine design, and could be different. The point here is that the UK government should not assume that other fuels need to be used to provide load following. The complexity of managing an electrical system with many different kinds of generating stations can be reduced by using nuclear power for load following as well as baseload power, and lower costs will result.
There are other benefits that are not quantified but make nuclear power attractive. Some reactors dissipate the exhaust heat from their turbines by evaporating water. These reactors could be fitted with sprayers that use this dissipating heat and water to form clouds containing very small water drops. Such clouds are extremely white and reflect sunlight back into space. Reactors fitted in this way could contribute to global cooling, going beyond merely being a zero carbon energy source. This has a significant economic value.
There are political costs associated with nuclear power. The association with military use has to be broken. For instance, the UK government should get rid of its nuclear weapons so it can develop commercial nuclear power without the distortions introduced by military requirements.