1. Place your chosen image here. The four corners must just cover the arrow tips. For covers, the three pictures should be the same size and in a straight line. Offtake Arrangements Work stream Mod 401 Clarification, November 2011

2. Clarification Summary – Our aim We aim to give examples of the scenarios where the DN could be subject to capacity overruns as a consequence of agreeing to lower pressures at offtakes We aim to explain how this can be quantified

3. OPN Revision Process (Flow swaps) DN or NTS request the OPN Revision Specify the Offtakes Specify the time Specify the Rates Aggregate rate must remain the same (LDZ or Exit Zone) Operational Reasons must be given (DN) Agree to revision (Safe and efficient) Submit revised OPN within 15 minutes – OAD I.2 and TPD J4.5.2.waived The difference between the prevailing OPN rates and the revised OPN rates will be clear

4. Scenario 1 – Straight Flow Swap AB BA 108 8 LDZ EOD flow not compromised 22

5. Scenario 2 – Flow Swap not possible AA 10 8 -2 EOD flow not achieved, 2mcm deficit Revised OPN – LDZ/Exit zone aggregate not achieved 2

6. Scenario 3 – Partial Flow Swap A B 10 B 9 A 8 EOD flow not achieved, 1mcm deficit Revised OPN – LDZ/Exit zone aggregate not achieved 2 1

7. Impact on following day (Scenario 3) 10 + 1 A A Invalid Overrun 8 If scenario 3 has occurred and an EOD Deficit has been identified on an offtake the subsequent OPN for the following day must include the deficit. If this causes the offtake to overrun, then up-to 1mcm overrun shall not apply. D A 11 + 1 Valid Overrun Invalid Overrun OR Next Day