Pyongyang responded angrily by vowing to resume Yongbyon's operations, then barring international inspectors from conducting their usual surveillance of the site.
If private plans demanded similar productivity savings from providers, and refused to let providers shift additional costs to them, the savings could be much larger.
The IAAF, which ordered the gender tests, refused to confirm or deny the reports. In a statement, the IAAF said it will issue a final decision in November.