Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2023-09-21 — OK
Operator
Transcontinental Gas Pipe Line Company
Cause
Material Failure Of Pipe Or Weld
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$273,825
Incident datetime
2023-09-21 00:00 UTC
Report number
Location
OK
Narrative
On wednesday, 08/23/2023 at approximately 3:07 pm est (15:07), operations was notified by the chief inspector for the tryon lateral anomaly digs and inspections that they had excavated, sand blasted, and were inspecting anomaly 24520 when they started smelling gas. The crew stood down and awaited operations arrival. Tryon lateral pipeline had already been isolated at station 140 and drawn down to 557 psi on 8/22/2023 in preparation for the anomaly digs planned to be started on 8/23/2023. Operations arrived at site with additional leak detection equipment at approximately 3:50 pm et (15:50) and began surveying for gas using an infrared optical gas detector with a pump near the anomaly inspection areas, detecting a leak at approximately 3:58 pm et (15:58). The leak was very small but registered gas with infrared leak detector cup immediately over region of crack area and caused readily visible bubbling of the snoop the ops techs notified ops manager at 4:10 pm et (16:10). It was decided that the isolated pipeline pressure would be further reduced to less than 400 psi which would result in calculated stress level of 24.6% smys. And in addition to the additional reduction in pressure, temporary repair clamps would be installed, and once installed, it would be safe to complete the remaining anomaly digs before coming back to cut out the leaking feature. Due to the proximity to a nearby home, it was decided to inform the resident of the situation and offer for them to go to a local hotel for the night. The resident accepted and vacated their home for approximately 24 hours until the temporary repair clamps were installed. Once it was decided that repair clamps would be utilized and that the local resident was leaving their home, the nrc was notified of the event. Station 140 was utilized to complete drawing down the tryon lateral pressures to 387 psi at 8:33 pm et (20:33). The lateral remained isolated overnight. The following morning, thursday, 8/24/2023, the temporary clamps arrived at station 140 at around 8:30 am et and were transported to the dig site to be installed. At 11:30 am et, clamp 1 installation was completed, leak checked, and no leaks present after installation. At 1:00 pm et (13:00), clamp 2 installation was completed, leak checked, and no leaks present after installation. Dig #14 (anomaly 24520) is being visited by operations / construction daily until the cutout and replacement to verify dig site is secure, fencing is in good shape, and to perform leak surveys to verify no leaks. Final: a cut-out and replacement of the affected area was completed on 05/29/2024 for a permanent repair. Metallurgical analysis for near identical anomalies in the area were recently conducted to support scc determination. Destructive testing was not conducted on this specific cut out so as not to ruin the sample for other lab analysis
Detailed record list
Report Received Date
2023-09-21 00:00:00
Iyear
2023
Report Number
20230091
Supplemental Number
40276
Report Type
Supplemental Final
Operator Id
19570
Name
Transcontinental Gas Pipe Line Company
Operator Street Address
One Williams Center Md 43-4
Operator City Name
Tulsa
Operator State Abbreviation
OK
Operator Postal Code
74172
Time Zone
Eastern
Daylight Savings Ind
Yes
Location Latitude
35.142778
Location Longitude
-82.177778
Nrc Rpt Num
1377064
Commodity Released Type
Natural Gas
Unintentional Release
0.92
Intentional Release
0
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Status When Identified
Normal Operation, Includes Pauses During Maintenance
Shutdown Due Accident Ind
No
Shutdown Explain
Line Isolated And Pressure Reduced For Digs Then Reduced Further Upon Discovery
Communication State Fed Ind
No
Ignite Ind
No
Upstream Action Taken
Operational Control
Upstream Oprtnl Cntrl Detail
Line Pressure Reduced And Clamps Installed 8 24 23
Downstream Action Taken
Operational Control
Downstream Oprtnl Cntrl Detail
Line Pressure Reduced And Clamps Installed 8 24 23
Num Pub Evacuated
3
On Off Shore
Onshore
Onshore State Abbreviation
Sc
Onshore Postal Code
29322
Onshore City Name
Campobello
Onshore County Name
Spartanburg
Designated Location
Milepost
Designated Name
23.18
Pipe Fac Name
Transco Pipeline
Segment Name
Tryon Lateral
Federal
No
Location Type
Pipeline Right-Of-Way
Incident Area Type
Underground
Incident Area Subtype
Exposed Due To Excavation
Other Underground Facilities
No
Crossing
No
Pipe Facility Type
Interstate
System Part Involved
Onshore Pipeline, Including Valve Sites
Item Involved
Pipe
Pipe Type
Pipe Body
Pipe Diameter
16
Puddle Weld Ind
No
Pipe Wall Thickness
0.25
Pipe Smys
52000
Pipe Specification
X52
Pipe Seam Type
Longitudinal Erw - Unknown Frequency
Pipe Manufacturer
Youngstown Sheet And Tube Company
Pipe Coating Type
Coal Tar
Coating Applied Ind
Yes
Installation Year
1967
Manufactured Year
1966
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Crack
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
312
Heat Damage Ind
No
Non Heat Damage Ind
No
Did Occur In Mca Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
3
Est Cost Intentional Release
0
Est Cost Prop Damage
273825
Est Cost Emergency
63890
Est Cost Other
0
Gas Cost In Mcf
3
Prpty
337718
Num Persons Hosp Not Ovnght
0
Num Injured Treated By Emt
0
Num Resident Building Affctd
1
Num Business Building Affctd
0
Wildlife Impact Ind
No
Accident Psig
530
Gas Flow In Pipe In Mcf
312
Mop Psig
800
Mop Cfr Section
192.619(A)(1)
Maop Established Date
1967-04-15 00:00:00
Maop Reversal Flow Ind
No
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
Yes
Exceed Restriction Ind
No
Phmsa Restriction Ind
Not Mandated
Gas Required Odorized Ind
No
Length Segment Isolated
74500
Internal Inspection Ind
Yes
Operation Complications Ind
No
Pipeline Function
Transmission System
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
No
Scada Conf Ind
No
Accident Identifier
Local Operating Personnel, Including Contractors
Operator Type
Operator Employee
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
Pressures did not exceed maop and a crack was found in the line
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Material Failure Of Pipe Or Weld
Cause Details
Environmental Cracking-Related
Pwjf Failure Type
Environmental Cracking-Related
Field Exam Ind
Yes
Stress Subtype
Stress Corrosion Cracking
Post Constr Pressure Test Val
Unknown
Collected Data Ind
Yes
Axial Magnetic Flx Lkg Ind
Yes
Cir Trn Wave Mgn Flx Lkg Ind
Yes
Geometry Deformation Ind
Yes
Emat Ind
Yes
Axial Recent Year
2021
Axial Rcnt Propul Method
Free Swimming
Axial Rcnt Attuned Detect
Metal Loss
Axial Rcnt Atnd Dtct Metal
High Resolution
Axial Previous Year
2017
Axial Prev Propul Method
Free Swimming
Axial Prev Attuned Detect
Metal Loss
Axial Prev Atnd Dtct Metal
High Resolution
Circ Wave Recent Year
2021
Circ Wv Rcnt Propul Method
Free Swimming
Circ Wv Rcnt Resolution
High Resolution
Circ Wv Previous Year
2017
Circ Wv Prev Propul Method
Free Swimming
Circ Wv Prev Resolution
High Resolution
Geometry Recent Year
2021
Geometry Rcnt Propul Method
Free Swimming
Geometry Rcnt Resolution
High Resolution
Geometrt Rcnt Measur Cups
No Cups
Geometry Previous Year
2017
Geometry Prev Propul Method
Free Swimming
Geometry Prev Resolution
High Resolution
Geometrt Prev Measur Cups
No Cups
Emat Recent Year
2022
Emat Rcnt Propul Method
Free Swimming
Has Hydrtst Conduc Before Ind
No
Direct Asmnt Conducted
No
Non Destructive Exam Ind
Yes
Exm Handl Ultrasonic Rcnt Year
2023
Exm Wet Mgnt Partcl Rcnt Year
2023
Exm Handl Ultrasonic Rcnt Ind
Yes
Exm Wet Mgnt Partcl Rcnt Ind
Yes
Pwf Manufacturing Ind
Yes
Preparer Name
M**** J****
Preparer Title
Pipeline Safety Engineer
Preparer Email
M**********@w*******.com
Preparer Telephone
3464264106
Authorizer Name
E*** W****
Authorizer Title
Manager Pipeline Safety
Authorizer Telephone
2815369504
Authorizer Email
E*********@w*******.com
Narrative
On wednesday, 08/23/2023 at approximately 3:07 pm est (15:07), operations was notified by the chief inspector for the tryon lateral anomaly digs and inspections that they had excavated, sand blasted, and were inspecting anomaly 24520 when they started smelling gas. The crew stood down and awaited operations arrival. Tryon lateral pipeline had already been isolated at station 140 and drawn down to 557 psi on 8/22/2023 in preparation for the anomaly digs planned to be started on 8/23/2023. Operations arrived at site with additional leak detection equipment at approximately 3:50 pm et (15:50) and began surveying for gas using an infrared optical gas detector with a pump near the anomaly inspection areas, detecting a leak at approximately 3:58 pm et (15:58). The leak was very small but registered gas with infrared leak detector cup immediately over region of crack area and caused readily visible bubbling of the snoop the ops techs notified ops manager at 4:10 pm et (16:10). It was decided that the isolated pipeline pressure would be further reduced to less than 400 psi which would result in calculated stress level of 24.6% smys. And in addition to the additional reduction in pressure, temporary repair clamps would be installed, and once installed, it would be safe to complete the remaining anomaly digs before coming back to cut out the leaking feature. Due to the proximity to a nearby home, it was decided to inform the resident of the situation and offer for them to go to a local hotel for the night. The resident accepted and vacated their home for approximately 24 hours until the temporary repair clamps were installed. Once it was decided that repair clamps would be utilized and that the local resident was leaving their home, the nrc was notified of the event. Station 140 was utilized to complete drawing down the tryon lateral pressures to 387 psi at 8:33 pm et (20:33). The lateral remained isolated overnight. The following morning, thursday, 8/24/2023, the temporary clamps arrived at station 140 at around 8:30 am et and were transported to the dig site to be installed. At 11:30 am et, clamp 1 installation was completed, leak checked, and no leaks present after installation. At 1:00 pm et (13:00), clamp 2 installation was completed, leak checked, and no leaks present after installation. Dig #14 (anomaly 24520) is being visited by operations / construction daily until the cutout and replacement to verify dig site is secure, fencing is in good shape, and to perform leak surveys to verify no leaks. Final: a cut-out and replacement of the affected area was completed on 05/29/2024 for a permanent repair. Metallurgical analysis for near identical anomalies in the area were recently conducted to support scc determination. Destructive testing was not conducted on this specific cut out so as not to ruin the sample for other lab analysis
| Report Received Date | 2023-09-21 00:00:00 |
|---|---|
| Iyear | 2023 |
| Report Number | 20230091 |
| Supplemental Number | 40276 |
| Report Type | Supplemental Final |
| Operator Id | 19570 PHMSA Enforcement |
| Name | Transcontinental Gas Pipe Line Company |
| Operator Street Address | One Williams Center Md 43-4 |
| Operator City Name | Tulsa |
| Operator State Abbreviation | OK |
| Operator Postal Code | 74172 |
| Time Zone | Eastern |
| Daylight Savings Ind | Yes |
| Location Latitude | 35.142778 Google Maps OpenStreetMap |
| Location Longitude | -82.177778 Google Maps OpenStreetMap |
| Nrc Rpt Num | 1377064 NRC Report How to search |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 0.92 |
| Intentional Release | 0 |
| Accompanying Liquid | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Status When Identified | Normal Operation, Includes Pauses During Maintenance |
| Shutdown Due Accident Ind | No |
| Shutdown Explain | Line Isolated And Pressure Reduced For Digs Then Reduced Further Upon Discovery |
| Communication State Fed Ind | No |
| Ignite Ind | No |
| Upstream Action Taken | Operational Control |
| Upstream Oprtnl Cntrl Detail | Line Pressure Reduced And Clamps Installed 8 24 23 |
| Downstream Action Taken | Operational Control |
| Downstream Oprtnl Cntrl Detail | Line Pressure Reduced And Clamps Installed 8 24 23 |
| Num Pub Evacuated | 3 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Sc |
| Onshore Postal Code | 29322 |
| Onshore City Name | Campobello |
| Onshore County Name | Spartanburg |
| Designated Location | Milepost |
| Designated Name | 23.18 |
| Pipe Fac Name | Transco Pipeline |
| Segment Name | Tryon Lateral |
| Federal | No |
| Location Type | Pipeline Right-Of-Way |
| Incident Area Type | Underground |
| Incident Area Subtype | Exposed Due To Excavation |
| Other Underground Facilities | No |
| Crossing | No |
| Pipe Facility Type | Interstate |
| System Part Involved | Onshore Pipeline, Including Valve Sites |
| Item Involved | Pipe |
| Pipe Type | Pipe Body |
| Pipe Diameter | 16 |
| Puddle Weld Ind | No |
| Pipe Wall Thickness | 0.25 |
| Pipe Smys | 52000 |
| Pipe Specification | X52 |
| Pipe Seam Type | Longitudinal Erw - Unknown Frequency |
| Pipe Manufacturer | Youngstown Sheet And Tube Company |
| Pipe Coating Type | Coal Tar |
| Coating Applied Ind | Yes |
| Installation Year | 1967 |
| Manufactured Year | 1966 |
| Material Involved | Carbon Steel |
| Release Type | Leak |
| Leak Type | Crack |
| Class Location Type | Class 1 Location |
| Could Be Hca | No |
| Pir Radius | 312 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Did Occur In Mca Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 3 |
| Est Cost Intentional Release | 0 |
| Est Cost Prop Damage | 273825 |
| Est Cost Emergency | 63890 |
| Est Cost Other | 0 |
| Gas Cost In Mcf | 3 |
| Prpty | 337718 |
| Num Persons Hosp Not Ovnght | 0 |
| Num Injured Treated By Emt | 0 |
| Num Resident Building Affctd | 1 |
| Num Business Building Affctd | 0 |
| Wildlife Impact Ind | No |
| Accident Psig | 530 |
| Gas Flow In Pipe In Mcf | 312 |
| Mop Psig | 800 |
| Mop Cfr Section | 192.619(A)(1) View CFR 49 §192 |
| Maop Established Date | 1967-04-15 00:00:00 |
| Maop Reversal Flow Ind | No |
| Accident Pressure | Pressure Did Not Exceed Maop |
| Pressure Restriction Ind | Yes |
| Exceed Restriction Ind | No |
| Phmsa Restriction Ind | Not Mandated |
| Gas Required Odorized Ind | No |
| Length Segment Isolated | 74500 |
| Internal Inspection Ind | Yes |
| Operation Complications Ind | No |
| Pipeline Function | Transmission System |
| Scada In Place Ind | Yes |
| Scada Operating Ind | Yes |
| Scada Functional Ind | Yes |
| Scada Detection Ind | No |
| Scada Conf Ind | No |
| Accident Identifier | Local Operating Personnel, Including Contractors |
| Operator Type | Operator Employee |
| 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 | Pressures did not exceed maop and a crack was found in the line |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Material Failure Of Pipe Or Weld |
| Cause Details | Environmental Cracking-Related |
| Pwjf Failure Type | Environmental Cracking-Related |
| Field Exam Ind | Yes |
| Stress Subtype | Stress Corrosion Cracking |
| Post Constr Pressure Test Val | Unknown |
| Collected Data Ind | Yes |
| Axial Magnetic Flx Lkg Ind | Yes |
| Cir Trn Wave Mgn Flx Lkg Ind | Yes |
| Geometry Deformation Ind | Yes |
| Emat Ind | Yes |
| Axial Recent Year | 2021 |
| Axial Rcnt Propul Method | Free Swimming |
| Axial Rcnt Attuned Detect | Metal Loss |
| Axial Rcnt Atnd Dtct Metal | High Resolution |
| Axial Previous Year | 2017 |
| Axial Prev Propul Method | Free Swimming |
| Axial Prev Attuned Detect | Metal Loss |
| Axial Prev Atnd Dtct Metal | High Resolution |
| Circ Wave Recent Year | 2021 |
| Circ Wv Rcnt Propul Method | Free Swimming |
| Circ Wv Rcnt Resolution | High Resolution |
| Circ Wv Previous Year | 2017 |
| Circ Wv Prev Propul Method | Free Swimming |
| Circ Wv Prev Resolution | High Resolution |
| Geometry Recent Year | 2021 |
| Geometry Rcnt Propul Method | Free Swimming |
| Geometry Rcnt Resolution | High Resolution |
| Geometrt Rcnt Measur Cups | No Cups |
| Geometry Previous Year | 2017 |
| Geometry Prev Propul Method | Free Swimming |
| Geometry Prev Resolution | High Resolution |
| Geometrt Prev Measur Cups | No Cups |
| Emat Recent Year | 2022 |
| Emat Rcnt Propul Method | Free Swimming |
| Has Hydrtst Conduc Before Ind | No |
| Direct Asmnt Conducted | No |
| Non Destructive Exam Ind | Yes |
| Exm Handl Ultrasonic Rcnt Year | 2023 |
| Exm Wet Mgnt Partcl Rcnt Year | 2023 |
| Exm Handl Ultrasonic Rcnt Ind | Yes |
| Exm Wet Mgnt Partcl Rcnt Ind | Yes |
| Pwf Manufacturing Ind | Yes |
| Preparer Name | M**** J**** |
| Preparer Title | Pipeline Safety Engineer |
| Preparer Email | M**********@w*******.com |
| Preparer Telephone | 3464264106 |
| Authorizer Name | E*** W**** |
| Authorizer Title | Manager Pipeline Safety |
| Authorizer Telephone | 2815369504 |
| Authorizer Email | E*********@w*******.com |
| Narrative | On wednesday, 08/23/2023 at approximately 3:07 pm est (15:07), operations was notified by the chief inspector for the tryon lateral anomaly digs and inspections that they had excavated, sand blasted, and were inspecting anomaly 24520 when they started smelling gas. The crew stood down and awaited operations arrival. Tryon lateral pipeline had already been isolated at station 140 and drawn down to 557 psi on 8/22/2023 in preparation for the anomaly digs planned to be started on 8/23/2023. Operations arrived at site with additional leak detection equipment at approximately 3:50 pm et (15:50) and began surveying for gas using an infrared optical gas detector with a pump near the anomaly inspection areas, detecting a leak at approximately 3:58 pm et (15:58). The leak was very small but registered gas with infrared leak detector cup immediately over region of crack area and caused readily visible bubbling of the snoop the ops techs notified ops manager at 4:10 pm et (16:10). It was decided that the isolated pipeline pressure would be further reduced to less than 400 psi which would result in calculated stress level of 24.6% smys. And in addition to the additional reduction in pressure, temporary repair clamps would be installed, and once installed, it would be safe to complete the remaining anomaly digs before coming back to cut out the leaking feature. Due to the proximity to a nearby home, it was decided to inform the resident of the situation and offer for them to go to a local hotel for the night. The resident accepted and vacated their home for approximately 24 hours until the temporary repair clamps were installed. Once it was decided that repair clamps would be utilized and that the local resident was leaving their home, the nrc was notified of the event. Station 140 was utilized to complete drawing down the tryon lateral pressures to 387 psi at 8:33 pm et (20:33). The lateral remained isolated overnight. The following morning, thursday, 8/24/2023, the temporary clamps arrived at station 140 at around 8:30 am et and were transported to the dig site to be installed. At 11:30 am et, clamp 1 installation was completed, leak checked, and no leaks present after installation. At 1:00 pm et (13:00), clamp 2 installation was completed, leak checked, and no leaks present after installation. Dig #14 (anomaly 24520) is being visited by operations / construction daily until the cutout and replacement to verify dig site is secure, fencing is in good shape, and to perform leak surveys to verify no leaks. Final: a cut-out and replacement of the affected area was completed on 05/29/2024 for a permanent repair. Metallurgical analysis for near identical anomalies in the area were recently conducted to support scc determination. Destructive testing was not conducted on this specific cut out so as not to ruin the sample for other lab analysis |
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