Sunday’s John Mitchell Memorial 5k Race/Walk at Wheaton College is scheduled to go on as planned, 13 days after the Boston Marathon bombing, according to Sandy Coleman, a spokeswoman for the college. She would not discuss details of public safety measures, but said the college works closely with the Norton Police Department. The race, which steps off at 9 a.m. and follows a course on campus, honors Mitchell, a college employee who died in 2011. He worked for the college for 18 years, most recently as a supervisor in building services. Proceeds from this year’s race will be used to build a picnic area dedicated to him, Coleman said.