The uranium spot price is closely tied to nuclear power plant restarts in Japan. However, it's now looking like a Japanese utility company's uranium stockpile sale could be another factor to rock the market.News surfaced recently that Tokyo Electric Power (TSE: 9501), or TEPCO, which has not consumed uranium since the 2011 Fukushima nuclear crisis, is planning to sell part of its uranium stockpile during its 2015 fiscal year in an effort to cut costs. The sale could add 6.56 million pounds of U3O8 equivalent to the spot market, according to Cantor Fitzgerald's Rob Chang. As of March 31, TEPCO had 17,570 tonnes of uranium, but that amount is expected to increase to 19,317 tonnes by the end of this fiscal year due to supply contracts. The company plans to restart its Kashiwazaki-Kariwa plant by October of this year, and intends to use most of its stockpile to power that. However, TEPCO has said that the current stockpile is capable of feeding the plant for 10 years. As a result, it will likely return some of its uranium to suppliers or "pay for the costs of uranium enrichment in kind, while it will also consider terminating uranium purchase contracts and reducing purchase volumes to streamline its business." That might sound negative, but Chang said in a note that the addition is being viewed as a "one-off necessary move by a struggling utility as opposed to a sign of widespread inventory dumping from Japan." He also said that despite TEPCO's restart and the other expected restarts in Japan, he still foresees an unavoidable supply deficit occurring in 2020.