Kansas City (Mo.) Public School Retirement System issued an RFP for a firm to perform a one-time audit of actuary W. Alfred Hayes & Co.'s actuarial assumptions, methodology and opinions, said Cecelia M. Carter, executive director. She said the $734 million pension fund performs a similar audit every five years or so, noting that she doesn't expect changes to be necessary. The RFP is available on the fund's website at www.kcpsrs.org. Proposals are due March 22. Fund officials expect to make a selection by April 1.