Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2023-12-08 — MI
Operator
Consumers Energy Co
Cause
Equipment Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$280,212
Incident datetime
2023-12-08 00:00 UTC
Report number
Location
MI
Narrative
On november 8, 2023, at approximately 12:11 hours consumers energy gas control received an alarm notification which indicated a possible fire at the st. Clair compressor station (plant 4 dehydration system building). The consumers energy st. Clair compressor station is in ira, michigan (st. Clair county). A station mechanic at the site was notified and confirmed activation of the plant fire-gate system occurred due to the fire detection alarm. Following the event, the plant was removed from service and the scene was made safe. Additional personnel were dispatched to the station to determine the potential cause of the activation. During the incident investigation, no notable indications of failures were present in the facility, but upon arrival, it was noted that a gap in the insulation on the reboiler exhaust stack was clearly visible and was presumed to be the source of a false trip indication to the fire-eye (in direct line of sight) due to the infrared irradiation from the pipe (operating as normal up to 1500 degree f). The insulation on the exhaust system was inspected with no notable issues observed, repaired, and returned to service on november 9, 2023. On november 10, 2023, at approximately 11:17 hours, less than 24 hours after the return to service consumers energy gas control received an alarm notification which indicated a possible fire at the st. Clair compressor station (plant 4 dehydration system building). The equipment was taken off-line, and all insulation was removed to permit physical inspection. Several cracked welds were identified on the exhaust line of the thermal oxidizer, super heater, and condensate collection system of the thermal oxidizer. Loose bolts were found in the flanged connections of the system, and an exhaust pipe slip joint connection to the exhaust stack was found to no longer be inserted into the fitting. Both events were reported to mpsc as required when an emergency shutdown system is activated, and gas released. However, a more in-depth visual inspection confirmed additional equipment damage anticipated to exceed PHMSA reporting criteria of $139,700. Additional investigations after the event have identified a concern relative to insufficient bolt torque specifications used during a 2020 repair to the system, pipe fabrication failure resulting in pre-stress being applied to the failed system connection points, and potential pinned pipe in a high thermal growth area of the system exacerbating stresses imparted to those same connection points. Further problem solving is required to determine the root cause of the failure. However, with the concerns defined, consumers energy has taken action to remediate each concern through a refabrication of the super heater vessel failed components, pipe assemblies found to be creating the pre-stress scenario, slip joint insertion was increased to avoid risk of the joint failing, application of torque specifications from the original equipment manufacturer, and implementation of a preventative maintenance schedule for re-validating torque on bolted connections following return to service. Further analysis is required to support confirmation of the pipe failure modes identified in the field and is presently underway. The original equipment manufacturer has been engaged in the review and repair plan and is supporting review of the stress analysis. Engineering support has been contracted to support model development of the system and execute a pipe stress analysis. Following the outcome of the modeling and validation of the failure modes, additional steps may be necessary to improve the integrity of the system and will be implemented accordingly. Further analysis confirmed the failure was a result of insufficient bolt torque specifications provided by the manufacturer during a previous repair to the system. The failure was a result of the bolts yielding and torque was lost through the thermal cycle causing bolts to loosen.
Detailed record list
Report Received Date
2023-12-08 00:00:00
Iyear
2023
Report Number
20230113
Supplemental Number
39276
Report Type
Supplemental Final
Operator Id
2748
Name
Consumers Energy Co
Operator Street Address
One Energy Plaza
Operator City Name
Jackson
Operator State Abbreviation
MI
Operator Postal Code
49201
Time Zone
Eastern
Daylight Savings Ind
Yes
Location Latitude
42.71873
Location Longitude
-82.71592
Nrc Rpt Num
1384593
Additional Nrc Report Numbers
1384627
Commodity Released Type
Natural Gas
Unintentional Release
0.81
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
Yes
Communication State Fed Ind
No
Ignite Ind
No
Num Pub Evacuated
0
On Off Shore
Onshore
Onshore State Abbreviation
Mi
Onshore Postal Code
48023
Onshore City Name
Ira
Onshore County Name
St. Clair
Designated Location
Not Applicable
Pipe Fac Name
St. Clair Compressor Station (Plant 4)
Segment Name
Dehydration System
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Aboveground
Incident Area Subtype
Inside A Building
Crossing
No
Pipe Facility Type
Intrastate
System Part Involved
Onshore Compressor Station Equipment And Piping
Item Involved
Dehydrator/drier/treater/scrubber
Installation Year
2018
Manufactured Year
2018
Material Involved
Material Other Than Carbon Steel Or Plastic
Material Details
Stainless Steel
Release Type
Other
Release Type Details
The Plant Safety System Identified A High Heat Signature On The Thermal Oxidizer Which Initiated A Firegate Activation
Class Location Type
Class 3 Location
Could Be Hca
Yes
Determination Method
Method1
Pir Radius
680
Heat Damage Ind
No
Non Heat Damage Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
2
Est Cost Intentional Release
0
Est Cost Prop Damage
280212
Est Cost Emergency
308
Est Cost Other
0
Gas Cost In Mcf
3.08
Prpty
280522
Num Persons Hosp Not Ovnght
0
Num Injured Treated By Emt
0
Num Resident Building Affctd
0
Num Business Building Affctd
0
Wildlife Impact Ind
No
Accident Psig
557.3
Gas Flow In Pipe In Mcf
557.3
Mop Psig
1440
Mop Cfr Section
192.619(A)(2)
Maop Established Date
1969-10-27 00:00:00
Maop Reversal Flow Ind
Bi-Directional
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Gas Required Odorized Ind
No
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
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
Control room operator responded as required when alarm was generated.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Equipment Failure
Cause Details
Other Equipment Failure
Eq Failure Type
Other Equipment Failure
Eq Failure Details
The Fastener Yielded At The Flange Connection Due To Thermal Stresses.
Eq Additional Thermal Ind
Yes
Preparer Name
C******* Q* K***
Preparer Title
Principal Engineer Technical Analyst
Preparer Email
C************@c********.com
Preparer Telephone
989-280-2963
Local Contact Name
C******* Q* K***
Local Contact Email
C************@c********.com
Local Contact Telephone
989-280-2963
Authorizer Name
J**** E* P****
Authorizer Title
Senior Manager Engineering
Authorizer Telephone
989-598-5031
Authorizer Email
J**********@c********.com
Narrative
On november 8, 2023, at approximately 12:11 hours consumers energy gas control received an alarm notification which indicated a possible fire at the st. Clair compressor station (plant 4 dehydration system building). The consumers energy st. Clair compressor station is in ira, michigan (st. Clair county). A station mechanic at the site was notified and confirmed activation of the plant fire-gate system occurred due to the fire detection alarm. Following the event, the plant was removed from service and the scene was made safe. Additional personnel were dispatched to the station to determine the potential cause of the activation. During the incident investigation, no notable indications of failures were present in the facility, but upon arrival, it was noted that a gap in the insulation on the reboiler exhaust stack was clearly visible and was presumed to be the source of a false trip indication to the fire-eye (in direct line of sight) due to the infrared irradiation from the pipe (operating as normal up to 1500 degree f). The insulation on the exhaust system was inspected with no notable issues observed, repaired, and returned to service on november 9, 2023. On november 10, 2023, at approximately 11:17 hours, less than 24 hours after the return to service consumers energy gas control received an alarm notification which indicated a possible fire at the st. Clair compressor station (plant 4 dehydration system building). The equipment was taken off-line, and all insulation was removed to permit physical inspection. Several cracked welds were identified on the exhaust line of the thermal oxidizer, super heater, and condensate collection system of the thermal oxidizer. Loose bolts were found in the flanged connections of the system, and an exhaust pipe slip joint connection to the exhaust stack was found to no longer be inserted into the fitting. Both events were reported to mpsc as required when an emergency shutdown system is activated, and gas released. However, a more in-depth visual inspection confirmed additional equipment damage anticipated to exceed PHMSA reporting criteria of $139,700. Additional investigations after the event have identified a concern relative to insufficient bolt torque specifications used during a 2020 repair to the system, pipe fabrication failure resulting in pre-stress being applied to the failed system connection points, and potential pinned pipe in a high thermal growth area of the system exacerbating stresses imparted to those same connection points. Further problem solving is required to determine the root cause of the failure. However, with the concerns defined, consumers energy has taken action to remediate each concern through a refabrication of the super heater vessel failed components, pipe assemblies found to be creating the pre-stress scenario, slip joint insertion was increased to avoid risk of the joint failing, application of torque specifications from the original equipment manufacturer, and implementation of a preventative maintenance schedule for re-validating torque on bolted connections following return to service. Further analysis is required to support confirmation of the pipe failure modes identified in the field and is presently underway. The original equipment manufacturer has been engaged in the review and repair plan and is supporting review of the stress analysis. Engineering support has been contracted to support model development of the system and execute a pipe stress analysis. Following the outcome of the modeling and validation of the failure modes, additional steps may be necessary to improve the integrity of the system and will be implemented accordingly. Further analysis confirmed the failure was a result of insufficient bolt torque specifications provided by the manufacturer during a previous repair to the system. The failure was a result of the bolts yielding and torque was lost through the thermal cycle causing bolts to loosen.
| Report Received Date | 2023-12-08 00:00:00 |
|---|---|
| Iyear | 2023 |
| Report Number | 20230113 |
| Supplemental Number | 39276 |
| Report Type | Supplemental Final |
| Operator Id | 2748 PHMSA Enforcement |
| Name | Consumers Energy Co |
| Operator Street Address | One Energy Plaza |
| Operator City Name | Jackson |
| Operator State Abbreviation | MI |
| Operator Postal Code | 49201 |
| Time Zone | Eastern |
| Daylight Savings Ind | Yes |
| Location Latitude | 42.71873 Google Maps OpenStreetMap |
| Location Longitude | -82.71592 Google Maps OpenStreetMap |
| Nrc Rpt Num | 1384593 NRC Report How to search |
| Additional Nrc Report Numbers | 1384627 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 0.81 |
| 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 | Yes |
| Communication State Fed Ind | No |
| Ignite Ind | No |
| Num Pub Evacuated | 0 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Mi |
| Onshore Postal Code | 48023 |
| Onshore City Name | Ira |
| Onshore County Name | St. Clair |
| Designated Location | Not Applicable |
| Pipe Fac Name | St. Clair Compressor Station (Plant 4) |
| Segment Name | Dehydration System |
| Federal | No |
| Location Type | Operator-Controlled Property |
| Incident Area Type | Aboveground |
| Incident Area Subtype | Inside A Building |
| Crossing | No |
| Pipe Facility Type | Intrastate |
| System Part Involved | Onshore Compressor Station Equipment And Piping |
| Item Involved | Dehydrator/drier/treater/scrubber |
| Installation Year | 2018 |
| Manufactured Year | 2018 |
| Material Involved | Material Other Than Carbon Steel Or Plastic |
| Material Details | Stainless Steel |
| Release Type | Other |
| Release Type Details | The Plant Safety System Identified A High Heat Signature On The Thermal Oxidizer Which Initiated A Firegate Activation |
| Class Location Type | Class 3 Location |
| Could Be Hca | Yes |
| Determination Method | Method1 |
| Pir Radius | 680 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 2 |
| Est Cost Intentional Release | 0 |
| Est Cost Prop Damage | 280212 |
| Est Cost Emergency | 308 |
| Est Cost Other | 0 |
| Gas Cost In Mcf | 3.08 |
| Prpty | 280522 |
| Num Persons Hosp Not Ovnght | 0 |
| Num Injured Treated By Emt | 0 |
| Num Resident Building Affctd | 0 |
| Num Business Building Affctd | 0 |
| Wildlife Impact Ind | No |
| Accident Psig | 557.3 |
| Gas Flow In Pipe In Mcf | 557.3 |
| Mop Psig | 1440 |
| Mop Cfr Section | 192.619(A)(2) View CFR 49 §192 |
| Maop Established Date | 1969-10-27 00:00:00 |
| Maop Reversal Flow Ind | Bi-Directional |
| Accident Pressure | Pressure Did Not Exceed Maop |
| Pressure Restriction Ind | No |
| Gas Required Odorized Ind | No |
| 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 | 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 | Control room operator responded as required when alarm was generated. |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Equipment Failure |
| Cause Details | Other Equipment Failure |
| Eq Failure Type | Other Equipment Failure |
| Eq Failure Details | The Fastener Yielded At The Flange Connection Due To Thermal Stresses. |
| Eq Additional Thermal Ind | Yes |
| Preparer Name | C******* Q* K*** |
| Preparer Title | Principal Engineer Technical Analyst |
| Preparer Email | C************@c********.com |
| Preparer Telephone | 989-280-2963 |
| Local Contact Name | C******* Q* K*** |
| Local Contact Email | C************@c********.com |
| Local Contact Telephone | 989-280-2963 |
| Authorizer Name | J**** E* P**** |
| Authorizer Title | Senior Manager Engineering |
| Authorizer Telephone | 989-598-5031 |
| Authorizer Email | J**********@c********.com |
| Narrative | On november 8, 2023, at approximately 12:11 hours consumers energy gas control received an alarm notification which indicated a possible fire at the st. Clair compressor station (plant 4 dehydration system building). The consumers energy st. Clair compressor station is in ira, michigan (st. Clair county). A station mechanic at the site was notified and confirmed activation of the plant fire-gate system occurred due to the fire detection alarm. Following the event, the plant was removed from service and the scene was made safe. Additional personnel were dispatched to the station to determine the potential cause of the activation. During the incident investigation, no notable indications of failures were present in the facility, but upon arrival, it was noted that a gap in the insulation on the reboiler exhaust stack was clearly visible and was presumed to be the source of a false trip indication to the fire-eye (in direct line of sight) due to the infrared irradiation from the pipe (operating as normal up to 1500 degree f). The insulation on the exhaust system was inspected with no notable issues observed, repaired, and returned to service on november 9, 2023. On november 10, 2023, at approximately 11:17 hours, less than 24 hours after the return to service consumers energy gas control received an alarm notification which indicated a possible fire at the st. Clair compressor station (plant 4 dehydration system building). The equipment was taken off-line, and all insulation was removed to permit physical inspection. Several cracked welds were identified on the exhaust line of the thermal oxidizer, super heater, and condensate collection system of the thermal oxidizer. Loose bolts were found in the flanged connections of the system, and an exhaust pipe slip joint connection to the exhaust stack was found to no longer be inserted into the fitting. Both events were reported to mpsc as required when an emergency shutdown system is activated, and gas released. However, a more in-depth visual inspection confirmed additional equipment damage anticipated to exceed PHMSA reporting criteria of $139,700. Additional investigations after the event have identified a concern relative to insufficient bolt torque specifications used during a 2020 repair to the system, pipe fabrication failure resulting in pre-stress being applied to the failed system connection points, and potential pinned pipe in a high thermal growth area of the system exacerbating stresses imparted to those same connection points. Further problem solving is required to determine the root cause of the failure. However, with the concerns defined, consumers energy has taken action to remediate each concern through a refabrication of the super heater vessel failed components, pipe assemblies found to be creating the pre-stress scenario, slip joint insertion was increased to avoid risk of the joint failing, application of torque specifications from the original equipment manufacturer, and implementation of a preventative maintenance schedule for re-validating torque on bolted connections following return to service. Further analysis is required to support confirmation of the pipe failure modes identified in the field and is presently underway. The original equipment manufacturer has been engaged in the review and repair plan and is supporting review of the stress analysis. Engineering support has been contracted to support model development of the system and execute a pipe stress analysis. Following the outcome of the modeling and validation of the failure modes, additional steps may be necessary to improve the integrity of the system and will be implemented accordingly. Further analysis confirmed the failure was a result of insufficient bolt torque specifications provided by the manufacturer during a previous repair to the system. The failure was a result of the bolts yielding and torque was lost through the thermal cycle causing bolts to loosen. |
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