A request for funding to commission a new “independent” report on the risk of cracks developing in a Suffolk nuclear reactor has been turned down because of a claim it would not represent good use of taxpayers’ money.

The Sizewell Stakeholder Group, which was set up by the Nuclear Decommissioning Authority (NDA), wants to engage independent nuclear consultancy John Large & Associates to carry out research on the defects found last year in two Belgian reactors and assess whether there is any implication for Sizewell B.

However, the NDA says it would not be good use of taxpayers’ money because there is already an “independent” report on the issue – compiled by the Office for Nuclear Regulation (ONR).

The ONR, which is responsible for nuclear security as well as safety, is government funded but regards itself as independent. However, critics say it is too close to the industry it regulates.

After pressure from the Shut Down Sizewell Campaign, the Sizewell Stakeholder Group (SSG) decided earlier this year to hold a public meeting over the risk of cracks developing in the pressure vessel “heart” of the Sizewell B reactor after reports of defects being discovered in similar reactors at Doel and Tihange in Belgium.

However, the NDA has rejected the SSG’s request to spend part of the group’s annual budget on commissioning a report and asking John Large to speak at the meeting, along with ONR officials.

The ONR has investigated the Belgian discoveries and has concluded there is no significant risk of similar defects occurring at Sizewell B because its pressure vessel had been made by a different company and subjected to more exhaustive tests.

Marianne Fellowes, SSG chair, said she believed there was a case for commissioning an independent assessment of the risks and was disappointed that the group could not have autonomy over its spending.

Pete Wilkinson, a co-opted SSG member and acting chairman of the local anti nuclear consortium, Together Against Sizewell C, said the NDA had an annual budget of £2.8billion and a chief executive earning £600,000 a year so the cost of commissioning research by John Large – about £2,500 - was “not a lot of money” in comparison.“It is scandalous that they are trying to put the squeeze on us,” he said.

Colin Tucker, Sizewell staff representative on the SSG, said the Belgian reactors concerned had now been given the go-ahead to re-start.

An NDA spokesman said: “The role of the ONR is to act as independent regulator. It has carried out its investigation and there is no need for further investigation.”