Authorities were investigating a possible radiation leak at the Waste Isolation Pilot Plant near Carlsbad, N.M. An air monitor detected radiation near the plant Friday night, KRQE-TV, Albuquerque, reported. However, it was unclear exactly how much radiation has been released from the WIPP. "Additional sampling is going on. We have employees sequestered in place so that we minimize any potential for airborne inhalation," said Department of Energy WIPP spokesperson Roger Nelson. Non-essential employees were allowed to return to their homes Saturday after undergoing radioactive contamination tests, the Carlsbad Current-Argus reported. "WIPP has acted quickly and cautiously to ensure the safety of personnel and the local community," said Rep. Steve Pearce Saturday afternoon. "My office remains in close contact with officials at WIPP. Full analysis of the readings is expected be available tomorrow." Facilities at WIPP are used to permanently dispose of low-level nuclear waste from government sites across the United States, the newspaper said. "These are radionuclides that are of a hazard if inhaled but it is not the kind of radiation that penetrates, and so the primary concern for the release of this nature is [through] the ventilation passageway and that's why our employees are sequestered in place," said Nelson. "I can't tell you the amount or level but they were elevated and above normal, above background [levels]," Nelson said of the radiation that was detected airborne near Panel 7, Room 7, in the south salt mine.