If you find the character ↻ (↻), i.e. U+21BB CLOCKWISE OPEN CIRCLE ARROW, acceptable for your needs (its arrow might not be placed the same way as in common reload icons), then you can use it rather safely:
.reload {
font-family: Lucida Sans Unicode
}<span class=reload>↻</span>The Lucida Sans Unicode font contains the symbol, and it is available in virtually any Windows system you can find these days. According to MS info, it was included even in Windows 98 (and Windows 95 plus).
Systems other than Windows can reasonably be expected to have the symbol in some font and to have browsers that know how to pick it up from some of them. And fonts containing it have rather similar shapes for it. (But if the symbol needs to match stylistically the text of your document, you need to study the situation in more detail and try to make sure that all fonts in your font list, or “font stack”, contain it.)