NORTHERN Territory traditional land owners joined commonwealth officials on a tour of a Spanish radioactive storage facility.

The federal government is planning to build a national nuclear waste dump at Muckaty Station in the NT.

Indigenous groups against the plan are challenging this in the Federal Court.

However, Northern Land Council (NLC), commonwealth and indigenous land owners recently travelled to Spain to inspect the El Cabril nuclear waste facility.

Beyond Nuclear Initiative coordinator Natalie Wasley says this is extreme and costly.

"To take a big trip overseas at quite a cost is really surprising," Ms Wasley told ABC radio.

"It seems any information sharing about the company that is intended to build (the dump) ... could be done by less expensive methods."

NLC chairman Wali Wunungmurra says formal talks will begin this week about a proposed second site on a different section of land on Muckaty Station.

The consultation process is expected to continue into next year.