Iran's powerful Guard rejects inspection of military sites
As far as I am concerned, if this is Tehran's official position, then it is a deal breaker.
Nuclear weapons are under the custody and supervision of the military in every nation that has declared itself to be a nuclear-weapon nation. Iran has long been suspected of running two parallel nuclear programs ... one program for the purpose of generating energy and another separate military program to fabricate nuclear warheads and ballistic delivery systems.
The P5+1 nations are negotiating with Iran for the express purpose of guaranteeing that an Iranian military program to acquire nuclear weapons is impossible under strict parameters and an intrusive inspections regimen for the duration of any mutually accepted deal. This lofty goal however, cannot be achieved without the capability of the IAEA to inspect military facilities suspected of nuclear weapons research or uranium enrichment.
Contrary to what is imagined or purported by some, such inspections are not requested on a whim. The IAEA has many highly sophisticated tools to detect possible activity without entering a facility. They would only request access to a military facility if unequivocal technical/documentary evidence exists which demands an in-depth examination to either verify or dismiss suspicions.
Without this critical capability, any P5+1 deal with Iran is illusion and a sham.