CREATE TABLE table_name_31 (season INTEGER, team_2 VARCHAR(255), team_1 VARCHAR(255), score VARCHAR(255))
What year did Bangkok University and Chunnam Dragons have a score of 0-0?
    
SQL: SELECT SUM(season) FROM table_name_31 WHERE team_1 = "bangkok university" AND score = "0-0" AND team_2 = "chunnam dragons"