TOKYO— Tokyo Electric Power Co. 's disaster plans greatly underestimated the scope of a potential accident at its Fukushima Daiichi nuclear plant, calling for only one stretcher, one satellite phone and 50 protective suits in case of emergencies.

Disaster-response documents for Fukushima Daiichi, examined by The Wall Street Journal, also contain few guidelines for obtaining outside help, providing insight into why Japan struggled to cope with a nuclear crisis after an earthquake and tsunami devastated the facility.

On Wednesday, the president of plant operator Tepco was hospitalized for dizziness, offering the latest sign of leadership trouble. Earlier in the disaster, Tepco was faulted for a sluggish initial response; now it appears that its written emergency plans were themselves inadequate.