"We need your help," begins the plaintive ad on the front of the Whitehaven News. Did you work at Sellafield in the 1960s, 1970s or 1980s? Were you by chance in the job of disposing of radioactive material? If so, the owners of Britain's nuclear waste dump would very much like to hear from you: they want you to tell them what you dumped - and where you put it.

The reason for the ad is simple: the Cumbrian facility's new operator, LLW Repository Ltd, has discovered that the historic records of disposal supposedly kept by the British state are far from complete.

"LLWR are looking for nuclear industry employees who have worked at Sellafield and have been involved in the consignment of waste to the Low Level Waste Repository near Drigg," the ad says.

"We are very keen to speak to people who were directly involved in consigning nuclear waste during the 1960s to the mid-1980s in order to build up a comprehensive picture of the waste inventory in the trenches."

According to Dick Razz, LLWR's managing director, the ad is an act of thoroughness not desperation. "We think it's important to gain as much information as possible to enable us to better analyse what we have here. We also need to combat some of the mythology and folklore that surrounds us here."

By "folklore", he means claims by local environmentalists that the site near the giant Sellafield atomic complex is awash with highly radioactive materials - even including some taken from theChernobyl reactor in Ukraine, site of a huge disastrous accident in 1986.

But the newspaper ad and Razz's remarks cut little ice with local greens. They say the need for such appeals does not bode well for any high-level waste dump being considered by the government in its drive to build a new generation of nuclear power plants; they also warn Drigg contains all sorts of waste, from Chernobyl and but also from another site in the US.

"If they can't even account for the lower category of radioactive wastes, what hope is there for the volumes of significantly more dangerous intermediate- and high-level wastes they now so desperately want to dump deep underground," said Martin Forwood of Cumbrians Opposed to a Radioactive Environment, or Core.

Forwood says that, despite the "low-level waste" tag, trenches at Drigg are believed to hold more dangerous material. "Information provided to Core in the 1990s revealed debris from the 1957 Windscale fire, materials from the US Three Mile Island reactor accident, and from the Chernobyl explosion," he said.

David Lowry, co-author of a history of nuclear waste management, is also worried. The book quotes a UK Atomic Energy Authority scientist, Dr Spence, warning in 1957 before Drigg opened that it was essential that an analytic controls system, ie, proper and accurate records, must be developed before storing of radioactive waste began, so it was known what was in store and where. This advice was dropped soon after by UKAEA, said Lowry.

The Nuclear Decommissioning Authority, the state-owned body that handed Drigg to the LLWR consortium of companies led by the Washington Group of America, defended the new operators, saying there was nothing exceptional about an appealt to help address any small holes in records.

"This is very, very low-level waste we;re talking about; gloves, paper and hospital waste and it's all carefully stored in cemented-up containers in a vault," said an NDA spokesman. It was "utter nonsense" that anything from Chernobyl or further afield was buried there.