BRUSSELS, May 20 (Reuters) - EU nations should carry out stress tests before the coming winter to work out how vulnerable they are if the crisis over Ukraine leads to a major gas supply disruption, according to a draft European Commission document seen by Reuters.
EU leaders early this year called on the Commission, the EU executive, to draw up a list of measures for the short and longer term after Russia's annexation of Ukraine's Crimea region raised concerns of possible supply disruption.
Before next winter, it calls on member states to perform a stress test of the EU energy system in the light of supply disruption risks and to develop back-up mechanisms such as increasing gas stocks and finding short-term ways to cut demand.
It also wants other major supplier countries to increase energy production, where possible, and global gas resources, such as liquefied natural gas, to be redirected to Europe.
Also, for the short-term, it suggests pooling part of existing EU energy stocks into a "virtual common capacity reserve". (Reporting by Barbara Lewis; Editing by Adrian Croft)