The asset allocation decision for nuclear decommissioning trusts highlights the need for a taxable asset allocation framework. Results depend critically on the tax and turnover rates assumed, as well as on the separation of total returns into price return and coupon or dividend return. Mean/variance analysis indicates that funds should switch from municipal to corporate bonds as the tax rate decreases. High turnover also favors corporates over municipals. A broad, index-type equity portfolio seems to dominate other equity investments. If dividend income is exempt from taxes, the investor should look to value funds.