The full title is: ‘ Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency’

The declarations and reservations of the treaty is available here on the IAEA website.

Bulgaria, Hungary, Mongolia, and Poland are the only countries to have ratified the treaty and later withdrawn. 122 countries are currently signatories.

All four countries have also withdrawn from the ‘Convention on Early Notification of a Nuclear Accident’. 127 countries are currently signatories to that treaty.

Quite a few countries have recorded reservations about the wording so it does seem like an unusually controversial treaty but what makes it completely unacceptable for Bulgaria, Hungary, Mongolia, and Poland?

  • 1
    FWIW, this is more consequential in Bulgaria which has two operating reactors and Hungary which has four (Hungary also has significant active nuclear physics science operations), although neither has nuclear weapons, than in Poland and Mongolia each of which have no reactors or nuclear weapons and are not home to any major nuclear physics scientific collaborations.
    – ohwilleke
    Sep 2, 2021 at 21:30
  • 5
    N.B. I actually found where IAEA seems to say that, but I'm not entirely convinced the interpretation (given in Wikipedia) is correct skeptics.stackexchange.com/questions/52294/… Sep 2, 2021 at 22:46
  • "Bulgaria, Hungary, Mongolia, and Poland are the only countries to have ratified the treaty and later withdrawn." What's your source for this?
    – Mast
    Sep 5, 2021 at 9:48
  • Can you add some more information, like dates for events (like withdrawals)? Sep 5, 2021 at 19:00
  • @Fizz is correct. The IAEA document to which you link is entitled "Agreement Reservations". It is a list of statements which the countries made when they signed the convention. The word "withdrawn" in the entries for these four countries does not refer withdrawal of the ratification, it refers to the withdrawal of the proviso in quotes after the colon. These countries have now ratified the convention without reservation.
    – David42
    Sep 7, 2021 at 11:15

2 Answers 2


Almost certainly didn't happen. Wikipedia makes/made the same claim about the four countries having withdrawn from the better known Convention on Early Notification of a Nuclear Accident. Both conventions were signed at about the same time (1986), in the aftermath of Chernobyl.

Both Hungary's and Poland's government agency websites say they are still in the Notification one, as well as in the Assistance one.

There's a clearer table at the UN's website on the Notification one. What happened is that a few countries later withdrew their reservations that had been made upon signature. Notably, most Eastern block countries, upon the 1986 signature, made a reservation about arbitration at ICJ, as did Russia and China. The few countries [in that group] that withdrew their reservation did so after the Berlin wall fell.

enter image description here

Now the Assistance treaty is much more obscure (and I could not find the UN table for it), but Poland's website says they're still in it, and so does Hungary's... so, I think it's reasonable to conclude that the other 2 countries are too.

enter image description here

Hungary is a contracting party to the following international conventions on the peaceful, safe and secured use of atomic energy

Convention on Early Notification of a Nuclear Accident (ENC)

Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (AC)

  • Thanks, that does seem like the most sensible reason for what the UN document means.
    – M. Y. Zuo
    Sep 4, 2021 at 15:06
  • Bulgaria has a checkmark in the "Withdrawal" column in an IEAE 2002 status report. The title includes both the Notification one and the Assistance one, but the table with the countries only mentions the Notification one. Sep 5, 2021 at 19:19

In the website of the Bulgarian nuclear regulator


both the "Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency" and "Convention on Early Notification of a Nuclear Accident" are listed as "ratified" and "legally binding" together with few other international agreements, administered by IAEA.

There is no mention of reservations, withdrawal or any other peculiarities. Both documents are considered an integral part of the Bulgarian legal framework.

Edit: I found the English version of the same page


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .