i stumbled across the same site awhile back and was dissapointed the whole thing (appears to be) a hoax..
from an ny times article:
About two years ago, Mr. Tatarchuk said, a Ukrainian woman booked a tour, wore a leather biker jacket and posed for pictures. Soon there appeared a Web site in which the woman, using the name Elena, claimed that she had been given an unlimited pass by her father, a nuclear physicist and Chernobyl researcher ("Thank you, Daddy!" she wrote) and now roamed the ruins at will on her Kawasaki Big Ninja.
source http://www.nytimes.com/2005/06/15/international/europe/15che...