NEC & EMERGENCY ARRANGEMENTS
Paul Green
2nd June 2005
NGT Emergency Planning
NEC & EMERGENCY ARRANGEMENTS
Preview



Emergency Procedures
NEC Safety Case
Changes to the NEC Safety Case
 Post Network sales
 Removal of Top-up

Summary
Emergency Procedures
Gas Safety (Management) Regulations 1996
GT Safety Case
NEC Safety Case
Transco/E/1
NGSE Procedure
Transco/E/2
LGSE Procedure
Produced by NTS Co
Produced by DNs collectively
XXX/E/3
Gas Act 1995
Unified
Network Code
Gas Safety (Management) Regulations






Places an obligation on all transporters to describe their arrangements for safe
management of network
 continuity of supply
 dealing with emergencies
Arrangements enforceable in criminal law.
Requirement for Network Emergency Coordinator
Identifies the Network
Safety Cases (NEC and GT)
Duty to Cooperate - Regulation 6(2)
NEC Safety Case


Identifies the NEC’s responsibilities
Defines the Network
 Primary
 Secondary
 Supplementary

Identifies types of gas supply emergencies on the primary system (NTS)
 Insufficient supplies to the primary system
 Transportation constraint




Identifies arrangements for managing gas supply emergencies
Describes the competency requirements of the NEC
Identifies who the NEC is
Approved by the HSE in March 2005
Role of the NEC
Primary Responsibility
 Coordinate of actions of Gas Transporters during a NGSE.
 Return the primary system to a supply demand balance
 Authorise each stage of a NGSE
 Submit and maintain a safety case
Secondary Responsibility
 Authorise the admittance of Emergency Specification Gas
 Test procedures as and when required
 Produce reports on any NGSE
 Authorise load reduction measures
NEC Safety Case Amendments





How the NEC is appointed
Use of public appeal at Stage 1 and 2
Reformatted to reflect GS(M)R
Reflects changes to the industry structure
Removal of Top Up and introduction of GS(M)R Safety Monitor Breach
NGSE
Communication Route updated to reflect
Network Sales
GS(M)R Safety Monitors
Customer
CustomerCatergory
Category
NTS Interuptible
Interruptible
Current
Previous
Proposed
New
Excluded
Excluded
LDZ Interuptible
Interruptible
NTS
NTSFirm
Firm
LDZ
LDZ Firm
Firm -- Daily
DailyMetered
MeteredI&C
I&C
Excluded
LDZ
LDZ Firm
Firm-- NDM
NDM
Firm
Firm "Priority"
"Priority"Customers
Customers
Irish
Irish Interconnector
Interconnector
Domestic
Domestic
Protected
Protected by Isolation
}
GS(M)R Monitors
•
Top Up was replaced by GS(M)R monitors last winter
•
Sites not protected by GS(M)R monitors protected by Isolation
•
Loads which do not require protection by GS(M)R monitor must have
•
•
Ability to remotely demonstrate zero flow (telemetry or datalogger)
Ability to be physically isolated
–
–
via remotely operable valve
be sufficiently small in number to allow field engineers to visit site and
close isolation valves (in the event of failure to cease gas flow)
GS(M)R Monitors

GS(M)R monitors are set for each storage category
– Long Range Storage (Rough)
– Medium Range Storage (Salt Cavity)
– Short Range Storage (LNG)



Lower level of demand to support hence lower monitor levels
Levels to decay through winter
In the coming winter if delivery of beach gas is reduced monitor levels
will be higher
GSMR Safety Monitor Breach
Network Gas Supply Emergency (NGSE)
Classification
Critical
Transportation
Constraint in the
NTS
Gas Deficit: Insufficient Gas Supplies
Available to the NTS
Gas Deficit
Emergency
(Section 4.3.1)
Emergency
Stage

1
(Potential)






2

3
4
5
1


Emergency Spec
Gas
NTS Linepack
Distribution
Network Storage
Emergency
Interruption
Public Appeal
1&2
OCM suspended
Maximise
Supplies
Public Appeal
1&2
Firm Load
Shedding
Allocation &
Isolation
Critical
Transportation
Constraint
(Section 4.3.3)
GSMR Monitor
Breach
(Section 4.3.2)

Instruct shippers
& storage
operators to
amend storage
flows

Emergency
Interruption

Public Appeal
1&2
OCM suspended
Maximise Supplies
Public Appeal 1&2

Firm Load Shedding

Allocation & Isolation

Restoration







Emergency Spec
Gas
NTS Linepack
Distribution
Network Storage
Emergency
Interruption
Public appeal 1&2
OCM remains in
place
Maximise Storage
Public Appeal 1&2
Firm Load
Shedding
Allocation &
Isolation
Stages of a Network Gas Supply Emergency
STAGE 1
Potential
Emergency Specification Gas
NTS Linepack & Network Storage
Storage Curtailment
Emergency Interruption
STAGE 2
Declaration
Maximise Beach Gas (GD)
Maximise Storage (GD & CTC)
Suspension of OCM (GD only)
STAGE 3
VLDMCs inc Interconnectors
Sites > 25,000 tpa
Public appeal message 1 and 2
Firm Load Shedding
STAGE 4
Isolation
STAGE 5
Restoration
Allocation
Isolation
Restoration of supply
Revoking of previous stages
Summary




NEC required under GS(M)R and is independent
Revised NEC Safety Case approved by HSE
Reflects changes to the industry post Network sales
Introduction of the GSMR Safety Monitor Breach emergency
 Protected by Monitor Consumers
 Protected by Isolation Consumers


Presentation to GEIEC in August
Any Questions?
NEC & EMERGENCY ARRANGEMENTS
Paul Green
2nd June 2005
NGT Emergency Planning