Communities interested in hosting an underground facility to house Britain’s most hazardous nuclear waste will be given the clearest possible picture of the materials to be stored there, the Government has said.

The reassurance from the Department for Business, Energy and Industrial Strategy (BEIS) comes after several additions and alterations were made to the draft National Policy Statement and Implementing Geological Disposal – Working with Communities documents following feedback from a cross-party select committee.

While the Government says there will be some uncertainty regarding the nation’s nuclear waste inventory, it will notify communities in the running to host the geological disposal facility (GDF) before the public is asked for its views, it said in response to recommendations made by the BEIS select committee.

The vast majority of radioactive waste to be stored at the facility will come from more than 60 years of civil nuclear and defence activity, much of which is already stored at the Sellafield site in West Cumbria.

The Government says around 10 per cent, in terms of volume, of waste to be stored in the GDF will come from new nuclear power stations, including Hinkley Point C in Somerset, although the figure could fluctuate, according to industry ambition.

A significant question mark hangs over waste from new power stations, with only Hinkley Point C having reached the construction phase.

The £15bn Moorside development in West Cumbria collapsed last year, while plans for stations at Wylfa Newydd, Anglesey and Oldbury in Gloucestershire have been mothballed.

Plans for Bradwell B in Essex and Sizewell C in Suffolk are progressing but are years away from the construction stage.

The BEIS select committee also said that the Government should be transparent on the level of radioactivity of waste coming from any new power stations.

“It is essential that communities understand what responsibility – both in terms of volume of waste and level of radioactivity – they would be signing up for by hosting the geological disposal

infrastructure,” the select committee said.

Pressing home the need for greater clarity on the issue, it added: “Although the National Policy Statement is primarily aimed at the Planning Inspectorate and the developer, it should also be helpful to communities that are thinking of volunteering to host the geological disposal infrastructure.”

While councils and landowners can express an interest in hosting GDF, geological experts would first have to rigorously assess any site’s suitability before the final decision going to the public – possibly in a referendum.

Cumbria has already been in the running to host GDF, but the process was abandoned in 2013 when Cumbria County Council withdrew – despite Copeland and Allerdale councils wanting to continue.

A new process to find a suitable site kicked off late last year, during which time the Government has been consulting on the best way to engage with communities.

The Government said it had taken the BEIS select committee’s recommendations on board and that a new paragraph had been added to the policy statement, stating: “Any application for development consent for a geological disposal facility must be accompanied by a statement setting out the nature and amount of waste expected to be disposed of at the relevant site."

It added: “This paragraph recognises that there may not be the capacity at any one site to take the entirety of the inventory, but that any geological disposal facility should be sized according to the inventory intended for disposal at that site, and the available capacity of the geology.”

The Government is understood to prefer to store the entire inventory at one GDF to help keep costs down and minimise the environmental impact of development.

A BEIS spokesman told in-Cumbria: “A geological disposal facility is internationally and independently accepted as the safest and most secure option for disposal of this waste, as recognised and supported by the cross-party BEIS select committee.”

“We have listened to views from local communities and these further measures will ensure this facility will only be built where there is public support for it.”

Councils is Cumbria are yet to take an official position on GDF.

Copeland Borough Council has already responded to the consultation and will make a formal response later in the year, a spokesman said.

At present, the council has no position on the siting of the facility, but, it said, it recognised that the Copeland community was affected regardless of the final choice of site for a GDF, given it is currently home to much of the waste that is to be stored there.

It has said, however, the target date for GDF of 2040 was unrealistic.

Elsewhere, the Government rejected a recommendation that it should refrain from drawing connections between the Industrial Strategy and geological disposal in order to justify its policy choices.

The Government said there were no references to the strategy – designed to boost the nation’s productivity – in the National Policy Statement but stressed the economic benefits it could bring.

Ahead of the launch of the latest process, then then energy minister Richard Harrington, said GDF could have a lifetime cost of £12bn to £20bn over 150 years, support up to 1,000 jobs at the peak of construction and 600 jobs a year when operational.

He added that more than 70,000 packages of waste are in above ground stores waiting for GDF.

The latest version of the NPS was laid in Parliament for a period of 21 sitting days last week, during which time a debate can be called in the House of Commons.

If no debate is called, or there is a debate and successful vote, the NPS can be designated. The 21 sitting days will bridge over the summer recess, which starts on July 25, with MPs returning on September 3.