EDITORIAL SANTA SUSANA COVER-UP WE HAVE A RIGHT TO KNOW WHOLE TRUTH ABOUT REACTOR MELTDOWN.

THE cover-up of what happened at the Santa Susana Field Laboratory in the Simi Hills above Chatsworth must end.

Evidence is compelling that the legacy of the field lab where nuclear and rocket research was conducted for decades is contaminated ground -- and the likelihood that hundreds of people in the San Fernando Valley area were exposed to radiation from the worst nuclear reactor accident in U.S. history.

The results of a seven-year state-funded study released last week indicate that the partial meltdown of the nuclear reactor at the lab in 1959 released more radiation than even the Three Mile Island incident. It may be responsible for hundreds of cancer cases in the area since, maybe as many as 1,800.

At the time of the incident half a century ago, the government's reaction was to cover up the meltdown. It wasn't until 1989 that the contamination of the lab was exposed at all, and only when the Daily News got hold of secret government reports.

At the same time, it was exposed that the lab site was also contaminated by extremely toxic dioxins, mercury and other heavy metals.

In the face of this new report that the radiation was even more widespread, the government and Boeing -- the company that's taken ownership of the contaminated site -- continue to stonewall. Officials brushed off this report as based on false presumptions, even though they withheld key information from researchers.

It's way beyond the point that a cover-up can work. We know that the site is tainted, and the government and the site's owners have a responsibility to neighboring communities to offer a full accounting of all the hazards at the lab site.

If ever there was a time for a complete debriefing of the toxic history of this hilltop site, this is it.

The truth, the whole truth, must come out.