The Tokyo Electric Power Company (TEPCO) on Monday said that high temperatures at reactor 2 at the Fukushima Daiichi power plant were likely due to a faulty thermometer.

In a statement, TEPCO said the temperature in the reactor was approximately 93.3 degrees Celsius (194 degrees Fahrenheit) as of midday on Monday. “We are now investigating the measuring instrument,” it said.

Two other thermometers at the same height both registered 33.1 C and 32.9 C, reported the Japan Times. Junichi Matsumoto, a TEPCO spokesperson, said, “The problematic one has stayed high, so we think it’s more likely now that the thermometer is broken rather than the temperature is actually rising.”

Toshihiro Yamamoto, a specialist in nuclear reactor safety at the Kyoto University Research Reactor Institute, told the newspaper, “It is unlikely the one showing 91.2 degrees is correct and the other two are incorrect because the other two show almost the same temperature.”

However, he stressed that TEPCO “should not rule out” that the thermometer is accurate despite the other two reading differently, the Times reported.

“If the temperature is really above 90 degree[s], there may be a spot in the pressure vessel that is not getting sprinkled with water. If nothing is done, the temperature will keep going up and the pressure vessel may get damaged. TEPCO will have to change the way it injects water or the amount of the water injected,” Yamamoto noted.