When Ian Harrison returned to the Lincolnshire coast to care for his parents a decade ago, he didn’t expect to spend his own retirement fighting plans to dig a £50bn nuclear waste dump near the beaches of his childhood.

Harrison, 67, lives a mile from the village of Theddlethorpe, one of three sites in England being examined for a possible geological disposal facility (GDF) to handle decades of nuclear waste from the power and defence industries. The cavernous dump will feature a series of tunnels and vaults dug 200-1,000 metres underground, capable of holding high-risk nuclear waste.

“It’s just a terrible idea to put a nuclear dump next to a seaside resort,” says Harrison, a retired warrant officer. “The safety concerns are real – look at Chernobyl – but people are more worried about the tourism that comes to Mablethorpe and the impact on local businesses.”

After several sites fell out of contention, the former gas terminal in Lincolnshire is one of just three which remain, with two on the Cumbrian coast – Mid Copeland and South Copeland. There is speculation about another site on the north-west coast.

The search for a home for Britain’s nuclear waste underlines a problem at the heart of its energy ambitions. Politicians have extolled the virtues of low-carbon nuclear power, but little attention has been given to the question of where to put the resulting waste.

Allerdale in Cumbria was ruled out last September after the government body behind the GDF project, Nuclear Waste Services (NWS), said there was “only a limited volume of suitable rock”, meaning it was not safe for storage. Last month, councillors in East Yorkshire withdrew from a process to consider hosting a GDF at South Holderness, east of Hull. In 2021, a council leader in Hartlepool resigned in a similar GDF row.

“At South Holderness, the local population complained and the council listened and stopped it,” says Harrison. “Here, people are worried, but they are sugarcoating it and not taking into account local concerns. Eventually, this will end up with a shortlist of one: us.”

The GDF is forecast to cost between £20bn and £53bn. Work on the project could take decades to begin, and high-risk waste will not enter it until at least 2075. The cost will be met by taxpayers, the existing nuclear plants’ operator EDF, and future power station operators.

Work on the GDF is expected to 4,000 jobs in its first 25 years. It is not an unprecedented move – Finland is nearing completion of a 450-metre-deep cavern to store its waste. France, Canada, Switzerland and Sweden are making progress on similar projects.

Britain’s nuclear waste is largely generated by its ageing power stations, as well as by industrial and defence sectors. It is housed in more than 20 ground-level sites which can hold the waste for up to 100 years, meaning a permanent store needs to be found. Even more waste is expected to be generated from a new era of reactors, despite lengthy delays,starting with Hinkley Point C in Somerset, currently the only new UK station under construction.

The handling of nuclear waste in Britain was put in the spotlight last year when the Guardian published Nuclear Leaks, a year-long investigation into problems with cyber­security, safety and a “toxic” culture at Sellafield. Most of the waste now at the Cumbria site will be sent to a GDF, probably between 2050 and 2125.

While it can be argued that the Copeland sites have communities familiar with nuclear waste, it is an alien industry for Theddlethorpe, where geologists are studying the clay rock under the seabed.

Proponents of a GDF at Theddlethorpe, where a facility would be built onshore and the store tunnelled under the sea six miles off the coast, argue it will bring not only jobs but investment – in flood defences, road improvements and rail links. Detractors say its largely retired community will barely contribute to the workforce, and its holiday parks will play host only to construction workers while tourism slowly dies. A government gaffe in which Skegness was wrongly spelled as “Skegross” on a map did little to engender local support.

Ken Smith, a retired former lecturer and chair of the Guardians of the East Coast pressure group, says: “People call us nimbys and tell us that we’re only interested in the impact on house prices, but that’s a red herring. It’s about the people who live here and the way this could change their lives.”

A test of public support for the Theddlethorpe project is likely to be conducted in 2027. Jon Collins, the independent chair of the Theddlethorpe GDF Community Partnership, says only a small number of the 10,000 people who live in the search area have yet expressed an opinion. “There are a lot of people who have yet to engage. People deserve the opportunity to have a proper debate with all the facts before a decision is made.”

In Mid Copeland, David Moore, 70, a retired farmer, says local support for the project has increased in recent years. “Our community has been brought up handling radioactive waste,” says Moore, a representative on the Mid Copeland GDF community partnership. “We have a highly skilled workforce, and know it brings highly paid jobs.” Residents in nearby South Copeland are more circumspect, he claims.

A contentious element of the project has been the £1m a year in funds offered to prospective sites, handed out by NWS. Spending has included £382,067 for an adventure playground, garden and CCTV at the village halls; £49,981 on a project to reduce loneliness; and £26,102 to the Parrot Zoo Trust. Some locals see the taxpayer money as a “bribe”; others argue the money might as well be taken while the debate continues.

Collins says any final decision needs to take into account both local opinion and the best geological conditions for the site.

But Smith says: “A GDF is simply sweeping the problem under the carpet. My worry is that I want future generations to enjoy what I have I can take my grandchildren for a picnic on the beach: you can’t do that at Sellafield. I do not want the area to be torn apart. If they industrialise this coastline then all that enjoyment will be lost.”

NWS said: “A GDF will only be built where there is a suitable site and a willing community. This is a consent-based process and we are committed to giving local people all the information they need, listening to all voices and letting local people have their say on the topic.”

• This article was amended on 5 March 2024 because an accompanying map graphic referred to South Holderness, Lincolnshire whereas it is in East Yorkshire.