TOKYO – Tokyo Electric Power Co. must speed up plans to cover reactors at its crippled nuclear plant and drain tainted water to prevent more radiation leaks as Japan’s cyclone season approaches, an engineering professor says.

In 2004, eight cyclones passed over or skirted Japan’s Tohoku region, where the Fukushima Dai-ichi power station is spewing radiation after an earthquake and tsunami on March 11. The earliest was in May that year, according to Japan’s weather agency data. The eyes of two storms passed within 300 kilometers of Tohoku last year, the data show.

Last month’s disaster wrecked the plant’s cooling systems, triggering the worst nuclear crisis since Chernobyl in 1986. The roofs of three buildings were damaged in blasts as water inside reactor cores and spent-fuel ponds boiled away. The utility known as Tepco plans to install temporary covers within nine months, and concrete ceilings over the “medium term.”

“The buildings should be covered at least before the typhoon season is in full swing by late July,” said Tadashi Narabayashi, a professor of nuclear engineering at Hokkaido University. “Tepco’s actions are like a game of Whack-a-Mole because the company keeps reacting after the event.”

Tepco said on Sunday it will start erecting temporary covers for the damaged building within three months provided radiation falls to levels at which workers can begin construction. The work is expected to be completed in the next three to six months, according to the action plan, which lists the “possibility of the cover being damaged by a big typhoon” as a risk.

The Japan Meteorological Agency doesn’t make forecasts for how many tropical storms or typhoons are expected to approach Japan, Hajime Takayama, a weather forecaster at the bureau, said by telephone.

“It’s quite possible for a typhoon to hit the Tohoku region while maintaining its strength, although most tend to make landfall in the south,” Takayama said.

The temporary covers are the only measures planned at the moment to protect against typhoons, Takeo Iwamoto, a Tepco spokesman, said by phone. The company may install them faster than the plan announced on Sunday, he said.

The Fukushima plant, 137 miles north of Tokyo, has six reactors, three of which were shut for maintenance when the earthquake and tsunami struck, leaving almost 28,000 people dead or missing.

Reactor buildings weakened by explosions may suffer further damage if a typhoon hits them, while strong winds and rain could scatter radioactive materials and water, said Hironobu Unesaki, a nuclear engineering professor at Kyoto University.