Japanese Officials? Please dont grind off the top layer of concrete! Will create radioactive dust regardless of control steps taken. Safer to encase with a non-porus material. One idea would be to put underlayment and then pour a two inch cap or if heavy traffic consult your engineers for a solution. The people putting their lives on the line should not work in vain! God bless, Peace, Love and Knowledge! Floyd Clifton Wooley Shown on The PBS News Hour!