TOKYO - A tsunami measuring about 3 meters high reached Japan's Shika nuclear power plant in Ishikawa prefecture following a powerful earthquake that struck the region on New Year's Day, according to the plant's operator.

The tsunami reached the facility at about 5:45 pm local time, approximately 90 minutes after the 7.6-magnitude quake hit the prefecture and its vicinity on Jan 1, Hokuriku Electric Power Company said Tuesday.

Hokuriku Electric said the waves did not cause safety problems at the plant, as it is built about 11 meters above sea level and has a 4-meter tall seawall.

The tsunami's height was not immediately known as data transmissions from a measuring device set on the seafloor stopped after the quake, the utility said.

The power company released the results of its data analysis of the water-level gauge near the Shika plant's seawater intake as well as the wave gauge near its wharf.

Meanwhile, Hokuriku Electric said that it discovered damage to some elements of equipment in a substation and power transmission lines, but the damage has no impact on the plant's operations.

Both the No 1 and No 2 reactors at the Shika plant were taken offline long before the earthquake.

Hokuriku Electric said on Jan 2 that it had not detected any significant change in the water levels on measuring equipment. But it later said a rise in the levels had been observed.