[from http://www.imra.org.il]

It is not clear to me why the White House and State Department websites have yet to post the actual 1,498 word English language text of the "Joint Action Plan" with Iran leaving readers to rely on the 2,192 word White House Fact Sheet that in many respects lacks some of the clarity that a legal document such
as the Joint Action Plan has.  A clarity, of course, that cuts both ways.

Consider the situation with Arak.

"On plutonium, we're putting on hold the most meaningful parts of their reactor that's currently under construction in a place called Arak, Iran." John Kerry Secretary of State November 26, 2013

"Iran has committed to no further advances of its activities at Arak..." White House Fact Sheet

The sentence construction of the actual "Joint Plan of Action" makes it crystal clear just how tightly defined the restricted "further advances" are :

"* Iran announces that it will not make any further advances of its activities at the Natanz Fuel Enrichment Plant (1), Fordow (2), or the Arak reactor (3)....

(3) Iran announces on concerns related to the construction of the reactor at Arak that for 6 months it will not commission the reactor or transfer fuel or heavy water to the reactor site and will not test additional fuel or produce more fuel for the reactor or install remaining components. "

Why the choice of the term "commission" rather than "construction".

Let's take a look at an official publication on the subject:

Commissioning of Nuclear Power Plants: Training and Human Resource
Considerations
INTERNATIONAL ATOMIC ENERGY AGENCY
VIENNA 2008

This publication is intended to apply to commissioning of NPP projects in Member States...

...Before a nuclear power plant is put into commercial operation, the functional adequacy of the installed components and systems, as well as the competencies of operating organization personnel must be tested to demonstrate that the plant can be operated safely and reliably. The main
objective of commissioning is to confirm that the design intent of the components, systems and the plant as a whole are achieved...

....for individual systems, exact borders between construction, commissioning and operation need to be defined.”

Simply put: The U.S. and other Western actors have tried to leave the impression that this deal actually prevents Iran from making progress at Arak when in fact it can continue onsite construction activity at Arak and continue preparing the remaining components for Arak - as long as they are
not installed after they are prepared.