The Nuclear Regulation Authority is moving toward the first reactor restart under its new safety requirements since the Fukushima disaster started, giving impetus to bond sales by utilities as borrowing costs plunge.

The regulator may submit a safety report on two reactors at Kyushu Electric Power Co.'s Sendai plant on July 16, paving the way for them to come online before year's end, the daily Yomiuri Shimbun reported this week. The utility is set to sell ¥20 billion ($197 million) in 10-year bonds Friday at 39 basis points over government debt, its lowest spread for such maturities since 2010, a source said.

Kansai Electric Power Co. and Shikoku Electric Power Co. also plan to offer notes this week as investors are drawn by the industry's higher-than-average yield premiums. Unprecedented Bank of Japan stimulus has pushed down Japanese corporate spreads to a seven-year low of 22 basis points. That for power companies' debt is 29 basis points, compared with 105 for utilities worldwide, Bank of America Merrill Lynch data show.