After days of warnings to students about radiation leaking from a damaged Japanese nuclear plant, Temple University officials on Thursday announced plans to evacuate Americans from their Tokyo campus.

A charter flight is being arranged to transport about 200 students in response to the fast-changing crisis at the Fukushima Dai-ichi generator, rocked in the devastating March 11 earthquake and tsunami. About 115 students already have left the country on their own, and 15 to 20 have left Tokyo for other places in Japan, university officials said.

The evacuation comes as the University of Pennsylvania and other U.S. colleges order or urge students out of Japan, and the State Department strongly urged U.S citizens to considering leaving amid the "deteriorating situation" at the plant.

Temple expects a flight to depart on Sunday, Japan time, its destination uncertain at present.

"We're working on it right now," said an exhausted Bruce Stronach, the Japan campus dean, reached by phone about 1:30 a.m. Tokyo time.

The school has been closed since the earthquake. Plans are to reopen the campus on March 28, but that date is subject to events.

The evacuation is not mandatory. Stronach has elected to stay behind, as have other staff. He was asked if he felt threatened by the radiation emanating from the plant, on the Japanese island of Honshu.

"Threatened, no. Nervous, yes," Stronach said. "I have lived in Japan for 22 of the last 35 years. I have been through many earthquakes. This is, without a doubt, 'the event.' "

Japanese authorities are using helicopters, fire trucks, and police cannons to pour on water, trying to keep the No. 3 reactor and its adjacent spent fuel pool from overheating. The quake damaged four of six reactors.

Four Penn students in Japan are now on their way home, university officials said, as fears of a nuclear meltdown prompt American colleges to bring back students and cancel travel plans for others.

The California State University system is bringing home about 45 students and calling off trips for another 50, and Stanford University announced that all 35 of its students have returned. Students from the University of North Dakota are back, while University of Wisconsin officials gave students the option to evacuate.

Temple University president Ann Weaver Hart credited Stronach and his staff for exemplary handling "of this trying and fast-evolving series of emergencies. They have worked tirelessly to keep our students safe."

No students or staff were injured in the quake or its aftermath.

The Temple campus in Tokyo is far from the damaged plant, roughly the distance from Philadelphia to Waterbury, Conn. But radiation is reaching the city in low levels, increasing concerns among Temple-Japan administrators.

On March 15, Stronach alerted students via the campus website that while radiation had been detected in Tokyo, the local government said the levels were not harmful. Still, the dean urged students to avoid going outside. If they must go outside, he wrote, they should wear hospital masks and long-sleeved shirts, and wash their faces and hands on returning.

On the 16th, Stronach's update informed staff and students that radiation levels were a fraction of those experienced in a routine chest X-ray, but still concerning.

"The real tipping point for us," sociology professor Kyle Cleveland said in a 3 a.m. phone interview, "was the U.S. government making its advisory."

In talking with students during the last few days, "I was amazed how calm and savvy they were. You could tell they were sorting through information. They were making some decisions. There's not a mad panic among the students at all," he said.

Many, in fact, are concerned about their academic credits, and the school is working on ways to enable students to finish the semester, he said.

Temple University Japan Campus, known as TUJ, is the oldest and largest foreign university in the country, founded in 1982. It serves about 3,300 undergraduates, graduate students, and corporate-education learners.

Its undergraduate students are 40 percent American, 42 percent Japanese, and 18 percent from more than 60 different nationalities.

Cleveland said he expected to escort some students out of the country, then return to Japan. He said he feels no sense of personal danger, but his wife's family lives about 30 miles from the nuclear plant, and "we're very concerned about them," Cleveland said.

He and others in Tokyo described a situation where food, fuel, and resources were being directed toward the disaster zone in northern Japan, causing long waits at gas stations and shortages of some items in grocery stores.

Samantha Landau, 27, a doctoral student at International Christina University near Tokyo, returned home to Wallingford on Tuesday, still shaken by what she had seen and experienced during and after the earthquake.

For days, the city continued to shake, she said, as aftershocks set buildings swaying. Public-address systems and cell-phone alerts for earthquakes and tsunamis went off constantly, and police and ambulance sirens wailed all day.

" 'Think logically and make a decision about whether to stay or go' - that's what I've been telling my friends," Landau said.

Several have already left the country, she said. Her trip home had been planned long ago. Otherwise, she would have moved farther south in Japan.

"The Japanese government keeps issuing these proclamations saying there's no danger," she said. "We'll see what happens. The people who are fighting the fires and the problems in the nuclear plants are going to be sick from this. They're very, very brave people."

Contact staff writer Jeff Gammage at 215-854-2415 or jgammage@phillynews.com.