Irecruitment - Create vacancies not for external

How do we create vacancies that are not for external candidates. As soon as we create vacancies, the view external candidates field is also available and if we give the end date of view external candidates field as the same date of creating the vacancies, still the external candidates can view the vacancies for 1 day. We donot want them to view it and it should be only for internal candidates. How can this be done.