GTG incident on 2012-11-11 — CO

Operator
Public Service Co Of Colorado
Cause
Corrosion Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$51,786
Incident datetime
2012-11-11 15:00
Report number
Location
CO
Narrative
On 11/11/12 at approximately 15:00 there was an unintentional release of 3,989 mcf (see part a, #10) of natural gas from an 8 inch steel transmission line, operating at 752 psig. Service was shut down at approximately 17:00 on 11/11/12 and restored on 11/12/12 at approximately 09:00. The rupture was caused by external galvanic corrosion attributed to a coating flaw (a holiday or disbonded region) that eroded wall thickness below threshold to contain operation pressure.
Detailed record list
Report Received Date
2012-12-11 00:00:00
Iyear
2012
Report Number
20120123
Supplemental Number
15894
Report Type
Supplemental Final
Operator Id
Name
Public Service Co Of Colorado
Operator Street Address
3500 Blake St
Operator City Name
Denver
Operator State Abbreviation
CO
Operator Postal Code
80205
Local Datetime
2012-11-11 15:00:00
Location Latitude
Location Longitude
Nrc Rpt Num
Nrc Rpt Datetime
2012-11-11 22:01:00
Commodity Released Type
Natural Gas
Unintentional Release
3989
Intentional Release
0
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
Yes
Shutdown Datetime
2012-11-11 17:00:00
Restart Datetime
2012-11-12 09:00:00
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2012-11-11 15:00:00
On Site Datetime
2012-11-11 16:00:00
On Off Shore
Onshore
Onshore State Abbreviation
Co
Onshore Postal Code
80498
Onshore City Name
Silverthorne
Onshore County Name
Summit
Designated Location
Survey Station No.
Designated Name
3328+18.55
Pipe Fac Name
8" Fraser To Frisco "a"
Segment Name
Plat Sheet 82 72012
Federal
No
Location Type
Pipeline Right-Of-Way
Incident Area Type
Underground
Incident Area Subtype
Under Soil
Depth Of Cover
48
Crossing
No
Pipe Facility Type
Intrastate
System Part Involved
Onshore Pipeline, Including Valve Sites
Item Involved
Pipe
Pipe Type
Pipe Body
Pipe Diameter
8.625
Pipe Wall Thickness
0.188
Pipe Smys
42000
Pipe Specification
Unknown
Pipe Seam Type
Longitudinal Erw - High Frequency
Pipe Manufacturer
Unknown
Pipe Coating Type
Cold Applied Tape
Installation Year
1969
Manufactured Year
1969
Material Involved
Carbon Steel
Release Type
Rupture
Rupture Orient
Longitudinal
Rupture Length
10.8
Rupture Width
4.3
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
167
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
16000
Est Cost Intentional Release
0
Est Cost Prop Damage
51786
Est Cost Emergency
0
Est Cost Other
0
Prpty
67786
Accident Psig
752
Mop Psig
790
Mop Cfr Section
Not On Omb-Approved Form When Submitted
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Upstream Valve Type Ind
Manual
Downstream Valve Type Ind
Manual
Length Segment Isolated
43824
Internal Inspection Ind
No
Tight Mitered Ind
Yes
Other Restrictions Ind
Yes
Operation Complications Ind
Yes
Other Complications Ind
Yes
Inspect Comp Details
Valve Spacing;need For Launger/receiver
Pipeline Function
Transmission System
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
Yes
Scada Conf Ind
Yes
Accident Identifier
Scada-Based Information (Such As Alarm(S), Alert(S), Event(S), And/or Volume Or Pack Calculations)
Investigation Status
No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate)
Investigation Status Details
The controllers did everything correctly.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Corrosion Failure
Cause Details
External Corrosion
Internal External
External Corrosion
Visual Exam Results
General Corrosion
Galvanic Corrosion Ind
Yes
Metallurgical Basis Ind
Yes
Underground Location
Yes
Under Cathodic Protection Ind
Yes
Cathodic Pro Start Year
1994
Shielding Evident
Yes
Cathodic Survey Type
Yes
Other Cp Survey Ind
Yes
Other Cp Survey Year
1994
Prior Damage
Yes
Collected Data Ind
Yes
Geometry Deformation Ind
Yes
Geometry Recent Year
1994
Has Hydrtst Conduc Before Ind
No
Direct Asmnt Conducted
No
Non Destructive Exam Ind
No
Preparer Name
D**** J******
Preparer Title
Investigator - Claims Services Department
Preparer Email
D**************@x*********.com
Preparer Telephone
303-294-2552
Preparer Fax
303-294-2311
Authorizer Name
A******* G******** F** J*** J K*****
Authorizer Title
Claims Manager Managing Investigator
Authorizer Telephone
303-294-2665
Authorizer Email
J************@x*********.com
Narrative
On 11/11/12 at approximately 15:00 there was an unintentional release of 3,989 mcf (see part a, #10) of natural gas from an 8 inch steel transmission line, operating at 752 psig. Service was shut down at approximately 17:00 on 11/11/12 and restored on 11/12/12 at approximately 09:00. The rupture was caused by external galvanic corrosion attributed to a coating flaw (a holiday or disbonded region) that eroded wall thickness below threshold to contain operation pressure.
Report Received Date 2012-12-11 00:00:00
Iyear 2012
Report Number 20120123
Supplemental Number 15894
Report Type Supplemental Final
Operator Id 15931 PHMSA Enforcement
Name Public Service Co Of Colorado
Operator Street Address 3500 Blake St
Operator City Name Denver
Operator State Abbreviation CO
Operator Postal Code 80205
Local Datetime 2012-11-11 15:00:00
Location Latitude 39.85065 Google Maps OpenStreetMap
Location Longitude -106.07956 Google Maps OpenStreetMap
Nrc Rpt Num 1030342 NRC Report How to search
Nrc Rpt Datetime 2012-11-11 22:01:00
Commodity Released Type Natural Gas
Unintentional Release 3989
Intentional Release 0
Accompanying Liquid 0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Shutdown Due Accident Ind Yes
Shutdown Datetime 2012-11-11 17:00:00
Restart Datetime 2012-11-12 09:00:00
Ignite Ind No
Explode Ind No
Num Pub Evacuated 0
Incident Identified Datetime 2012-11-11 15:00:00
On Site Datetime 2012-11-11 16:00:00
On Off Shore Onshore
Onshore State Abbreviation Co
Onshore Postal Code 80498
Onshore City Name Silverthorne
Onshore County Name Summit
Designated Location Survey Station No.
Designated Name 3328+18.55
Pipe Fac Name 8" Fraser To Frisco "a"
Segment Name Plat Sheet 82 72012
Federal No
Location Type Pipeline Right-Of-Way
Incident Area Type Underground
Incident Area Subtype Under Soil
Depth Of Cover 48
Crossing No
Pipe Facility Type Intrastate
System Part Involved Onshore Pipeline, Including Valve Sites
Item Involved Pipe
Pipe Type Pipe Body
Pipe Diameter 8.625
Pipe Wall Thickness 0.188
Pipe Smys 42000
Pipe Specification Unknown
Pipe Seam Type Longitudinal Erw - High Frequency
Pipe Manufacturer Unknown
Pipe Coating Type Cold Applied Tape
Installation Year 1969
Manufactured Year 1969
Material Involved Carbon Steel
Release Type Rupture
Rupture Orient Longitudinal
Rupture Length 10.8
Rupture Width 4.3
Class Location Type Class 1 Location
Could Be Hca No
Pir Radius 167
Heat Damage Ind No
Non Heat Damage Ind No
Hca Fatalities Ind No
Est Cost Oper Paid 0
Est Cost Unintentional Release 16000
Est Cost Intentional Release 0
Est Cost Prop Damage 51786
Est Cost Emergency 0
Est Cost Other 0
Prpty 67786
Accident Psig 752
Mop Psig 790
Mop Cfr Section Not On Omb-Approved Form When Submitted View CFR 49 §192
Accident Pressure Pressure Did Not Exceed Maop
Pressure Restriction Ind No
Upstream Valve Type Ind Manual
Downstream Valve Type Ind Manual
Length Segment Isolated 43824
Internal Inspection Ind No
Tight Mitered Ind Yes
Other Restrictions Ind Yes
Operation Complications Ind Yes
Other Complications Ind Yes
Inspect Comp Details Valve Spacing;need For Launger/receiver
Pipeline Function Transmission System
Scada In Place Ind Yes
Scada Operating Ind Yes
Scada Functional Ind Yes
Scada Detection Ind Yes
Scada Conf Ind Yes
Accident Identifier Scada-Based Information (Such As Alarm(S), Alert(S), Event(S), And/or Volume Or Pack Calculations)
Investigation Status No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate)
Investigation Status Details The controllers did everything correctly.
Employee Drug Test Ind No
Contractor Drug Test Ind No
Cause Corrosion Failure
Cause Details External Corrosion
Internal External External Corrosion
Visual Exam Results General Corrosion
Galvanic Corrosion Ind Yes
Metallurgical Basis Ind Yes
Underground Location Yes
Under Cathodic Protection Ind Yes
Cathodic Pro Start Year 1994
Shielding Evident Yes
Cathodic Survey Type Yes
Other Cp Survey Ind Yes
Other Cp Survey Year 1994
Prior Damage Yes
Collected Data Ind Yes
Geometry Deformation Ind Yes
Geometry Recent Year 1994
Has Hydrtst Conduc Before Ind No
Direct Asmnt Conducted No
Non Destructive Exam Ind No
Preparer Name D**** J******
Preparer Title Investigator - Claims Services Department
Preparer Email D**************@x*********.com
Preparer Telephone 303-294-2552
Preparer Fax 303-294-2311
Authorizer Name A******* G******** F** J*** J K*****
Authorizer Title Claims Manager Managing Investigator
Authorizer Telephone 303-294-2665
Authorizer Email J************@x*********.com
Narrative On 11/11/12 at approximately 15:00 there was an unintentional release of 3,989 mcf (see part a, #10) of natural gas from an 8 inch steel transmission line, operating at 752 psig. Service was shut down at approximately 17:00 on 11/11/12 and restored on 11/12/12 at approximately 09:00. The rupture was caused by external galvanic corrosion attributed to a coating flaw (a holiday or disbonded region) that eroded wall thickness below threshold to contain operation pressure.

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