A district council in South Korea's capital is grappling with a weighty waste management problem -- finding somewhere to dump a radioactive road.

Nowon district in northeastern Seoul is trying to dispose of 330 tonnes of asphalt after excavating two sections of the offending roadway earlier this month.

Alarmed by Japan's nuclear disaster in March, some South Koreans bought Geiger counters and used them to survey their own neighbourhoods.

One Nowon resident on November 1 reported that the road was recording radiation levels 10 times higher than normal.

Authorities said the amount was too small to pose any health risks but the district council dug up the asphalt following calls from anxious residents.

But the council came under fire a week ago when it was discovered that many chunks of asphalt had been dumped in a park. Officials have now moved the material to the back of their office.

"No one wants the material around their home so it is stuck in the backyard of our own office," a Nowon district office spokeswoman told AFP.

She urged the city and nuclear safety agencies to help pay to ship the material to a radioactive waste site, saying unnerved residents living near the office were already complaining.

"It'll cost nearly 10 billion won ($8.7 million) to buy special containers to carry the material to waste sites, if they accept them at all. We don't have that much money," the spokeswoman said.

The Nuclear Safety and Security Commission said an hour-long exposure to the road every day for an entire year would amount to less than half the annual permissible dose of radiation.

A commission official said investigations were under way into how the road material became radioactive. Media reports say this could have happened when the asphalt was manufactured.

"Regardless of the cause, the amount we found in the area posed no health risks. But the district officials repaved the road anyway," a NSSC official who declined to be named told AFP.

"We have no responsibility to pick up the slack for their political decisions."