I doubt that anything will ever interrupt the operation of any nuclear power plant in Japan at this point, short of what has happened in Fukushima I Nuclear Power Plant.
From NHK News (link to a backup site, part; 7/25/2012):
At Ooi Nuclear Power Plant, following Reactor 3 on July 9, Reactor 4 reached the full operation at 1AM on July 25 with officials including Senior Vice Minister of Economy, Trade and Industry Makino attending in the central control room.
In Reactor 4 however, an alarm was triggered at 5:30AM on July 25. It was one of the thermometers that triggered the alarm which are used to monitor the temperature of the primary coolant inside the reactor.
This thermometer monitors the temperature of the primary coolant, and if the temperature reaches 336 degrees Celsius it sets off an alarm. In the morning of July 25, this temperature was momentarily exceeded [according to KEPCO].
The other thermometers monitoring the primary coolant show normal temperatures, and there is no abnormal data such as the pressure of the reactor. KEPCO believes the alarm at the thermometer was due to a temporary rise in temperature due to water flow, and says the company continues to monitor the situation but without lowering the output.
With Reactors 3 and 4 at Ooi Nuclear Power Plant, which have the largest output capacities among the reactors operated by KEPCO, in full operation, the national government will remove the numerical targets for power saving in the areas served by Hokuriku Electric, Chubu Electric, and Chugoku Electric [who were required to deliver power to KEPCO in case of power shortage in KEPCO area].
Ooi's Reactors 3 and 4 are pressurized-water reactors.
By the way, the organizers who have been organizing the Friday protest at the Prime Minister's Official Residence in Tokyo says they are not doing it this week in order to focus their effort on the big July 29 event to surround the National Diet Building. They don't seem particularly worried about Ooi Nuke Plant any more, and one of the organizers continues to trash "the old left" who either come to the protest with labor union flags or argue with the police.
(I heard rumors that people are doing the "Kantei (PM Official Residence) demo" on Friday anyway. That would be interesting...)