to accumulate /əˈkjumjəˌleɪt/ /əˈkjuːmjəleɪt/
to store /stɔːr/ /stɔː/
to stockpile /ˈstɑːkpaɪl/ /ˈstɒkpaɪl/
to fill /fɪl/ /fɪl/
to fill up /fɪl ʌp/ /fɪl ʌp/