Incident details
Operator, cause, commodity and consequences with raw source fields.
GD incident on 2021-11-21 — AK
Operator
Interior Gas Utility
Cause
Incorrect Operation
Commodity
Natural Gas
Program
GD
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$32,000
Incident datetime
2021-11-21 17:14
Report number
Location
AK, FAIRBANKS NORTH STAR BOROUGH
Narrative
The interior gas utility (igu) lng storage and vaporization site number 3 (ss3) in fairbanks, alaska sent cold gas and possibly lng to the distribution system. When the cold gas or lng entered the distribution system, it embrittled the 8' underground hdpe pipe, which subsequently ruptured in a section of piping within igu property. The highest recorded pressure downstream of the distribution regulators at ss3 was 62psig. At approximately 4:10pm on 11/21/2021, a temperature switch on the outlet of the vaporizer malfunctioned and closed a valve to stop the flow of lng through the vaporizer. With no lng to vaporize, the glycol heater turned off due to low demand. At about 4:55pm, an operator noticed that the flow of lng had stopped, and the distribution pressure was dropping. The operator opened the closed vaporizer valve via remote control. The operator did not notice that the boiler was not firing and did not monitor the site long enough to verify the system was stable and proper temperatures where being maintained. Due to the malfunctioning temperature switch and a temperature transmitter that had not been programmed to act as a backup to the temperature switch, the control system did not stop the flow of lng through the vaporizer, upon a low gas temperature on the outlet of the vaporizer. The boiler attempted to fire about three minutes after the lng flow resumed but failed to stay running. The system attempted to start a back-up boiler about 10 minutes later, about when the distribution line ruptured. The standard operating procedures will be revised to no longer allow control changes from via remote control (except for emergency shut downs and specified exceptions) and instead require the monitoring operator to travel to the site to make the necessary adjustments and changes. The vaporizer temperature switches will be recommissioned, and the temperature transmitters will be added into the vaporizer shutdown programming logic to add redundancy. Additionally, a downstream temperature transmitter located on the meter skid will be used to shut down the lng pumps if low temperature is detected indicating the vaporizer shutdowns failed to activate as a result of low outlet temperature.
Detailed record list
Occurred At
2021-11-21 17:14:00
Year
2021
Report Received Date
2021-12-20 00:00:00
Iyear
2021.0
Report Number
20210102.0
Supplemental Number
36161.0
Report Type
Original Final
Operator Id
39257
Name
Interior Gas Utility
Operator Street Address
2525 Phillips Field Road
Operator City Name
Fairbanks
Operator State Abbreviation
AK
Operator Postal Code
99709
Local Datetime
2021-11-21 17:10:00
Time Zone
Alaska
Daylight Savings Ind
No
Location Street Address
2942 Tria Road
Location City Name
Fairbanks
Location County Name
Fairbanks North Star Borough
Location State Abbreviation
AK
Location Postal Code
99709
Location Latitude
64.80381
Location Longitude
-147.79728
Flow Cont Key Crit Ind
Yes
Flow Cont Meter Reg Ind
Yes
Nrc Rpt Datetime
2021-11-22 10:10:00
Nrc Rpt Num
1322689
Additional Nrc Report Numbers
1322785
Commodity Released Type
Natural Gas
Unintentional Release
559.0
Intentional Release
0.0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Ignite Ind
No
Num Pub Evacuated
0.0
Incident Identified Datetime
2021-11-21 17:14:00
Communication State Fed Ind
No
On Site Datetime
2021-11-21 17:44:00
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Underground
Incident Area Subtype
Under Soil
Depth Of Cover
40.0
Other Underground Facilities
No
Crossing
No
Pipe Facility Type
Municipally Owned
System Part Involved
Main
Installation Year
2019.0
Pipe Diameter
8.0
Pipe Specification
Astm D2513
Pipe Manufacturer
Performance Pipe
Material Involved
Plastic
Plastic Type
Polyethylene (Pe)
Plastic Sdr
11
Material Pe Pipe Code
3408
Release Type
Rupture
Rupture Orient
Other
Rupture Details
Spiral
Rupture Length
120
Rupture Width
0.5
Class Location Type
Class 2 Location
Est Cost Oper Paid
10000.0
Est Cost Prop Damage
32000.0
Est Cost Emergency
25000.0
Est Cost Other
0.0
Gas Cost In Mcf
11.704
Est Cost Unintentional Release
6543.0
Est Cost Intentional Release
0.0
Prpty
73543.0
Commercial Affected
91.0
Industrial Affected
0.0
Residences Affected
48.0
Num Persons Hosp Not Ovnght
0.0
Num Injured Treated By Emt
0.0
Num Resident Building Affctd
144.0
Num Business Building Affctd
91.0
Accident Psig
62.0
Normal Psig
55.0
Mop Psig
60.0
Mop Cfr Section
192.621 M
Maop Established Date
1998-06-01 00:00:00
Accident Pressure
Pressure Exceeded Maop, But Did Not Exceed The Applicable Allowance In 192.201
Gas Odorized System Type
Injection Pump
Gas Odorized Lvl Not Msrd Ind
Yes
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
No
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
Yes, specify investigation result(s): (select all that apply)
Invest Incorrect Action Ind
Yes
Invest Incorrect Procedure Ind
Yes
Invest Incorrect Control Ind
Yes
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Incorrect Operation
Cause Details
Valve Left Or Placed In Wrong Position, But Not Resulting In An Overpressure
Operation Type
Valve Left Or Placed In Wrong Position, But Not Resulting In An Overpressure
Related Inadequate Proc Ind
Yes
Category Type
Non-Routine Operating Conditions (Abnormal Operations Or Emergencies)
Operator Qualification Ind
Yes
Qualified Individuals
Yes, They Were Qualified For The Task(S)
Eqf Control Releaf Ind
Yes
Io Not Installed Properly Ind
Yes
Io Inadequate Procedure Ind
Yes
Preparer Name
E*** W*****
Preparer Title
Mechanical Engineer
Preparer Email
E******@i**********.com
Preparer Telephone
9074527111
Preparer Fax
9074578111
Authorizer Name
D** B******
Authorizer Title
General Manager
Authorizer Telephone
9074527111
Authorizer Email
D********@i**********.com
Narrative
The interior gas utility (igu) lng storage and vaporization site number 3 (ss3) in fairbanks, alaska sent cold gas and possibly lng to the distribution system. When the cold gas or lng entered the distribution system, it embrittled the 8' underground hdpe pipe, which subsequently ruptured in a section of piping within igu property. The highest recorded pressure downstream of the distribution regulators at ss3 was 62psig. At approximately 4:10pm on 11/21/2021, a temperature switch on the outlet of the vaporizer malfunctioned and closed a valve to stop the flow of lng through the vaporizer. With no lng to vaporize, the glycol heater turned off due to low demand. At about 4:55pm, an operator noticed that the flow of lng had stopped, and the distribution pressure was dropping. The operator opened the closed vaporizer valve via remote control. The operator did not notice that the boiler was not firing and did not monitor the site long enough to verify the system was stable and proper temperatures where being maintained. Due to the malfunctioning temperature switch and a temperature transmitter that had not been programmed to act as a backup to the temperature switch, the control system did not stop the flow of lng through the vaporizer, upon a low gas temperature on the outlet of the vaporizer. The boiler attempted to fire about three minutes after the lng flow resumed but failed to stay running. The system attempted to start a back-up boiler about 10 minutes later, about when the distribution line ruptured. The standard operating procedures will be revised to no longer allow control changes from via remote control (except for emergency shut downs and specified exceptions) and instead require the monitoring operator to travel to the site to make the necessary adjustments and changes. The vaporizer temperature switches will be recommissioned, and the temperature transmitters will be added into the vaporizer shutdown programming logic to add redundancy. Additionally, a downstream temperature transmitter located on the meter skid will be used to shut down the lng pumps if low temperature is detected indicating the vaporizer shutdowns failed to activate as a result of low outlet temperature.
| Occurred At | 2021-11-21 17:14:00 |
|---|---|
| Year | 2021 |
| Report Received Date | 2021-12-20 00:00:00 |
| Iyear | 2021.0 |
| Report Number | 20210102.0 |
| Supplemental Number | 36161.0 |
| Report Type | Original Final |
| Operator Id | 39257 PHMSA Enforcement |
| Name | Interior Gas Utility |
| Operator Street Address | 2525 Phillips Field Road |
| Operator City Name | Fairbanks |
| Operator State Abbreviation | AK |
| Operator Postal Code | 99709 |
| Local Datetime | 2021-11-21 17:10:00 |
| Time Zone | Alaska |
| Daylight Savings Ind | No |
| Location Street Address | 2942 Tria Road |
| Location City Name | Fairbanks |
| Location County Name | Fairbanks North Star Borough |
| Location State Abbreviation | AK |
| Location Postal Code | 99709 |
| Location Latitude | 64.80381 Google Maps OpenStreetMap |
| Location Longitude | -147.79728 Google Maps OpenStreetMap |
| Flow Cont Key Crit Ind | Yes |
| Flow Cont Meter Reg Ind | Yes |
| Nrc Rpt Datetime | 2021-11-22 10:10:00 |
| Nrc Rpt Num | 1322689 NRC Report How to search |
| Additional Nrc Report Numbers | 1322785 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 559.0 |
| Intentional Release | 0.0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Ignite Ind | No |
| Num Pub Evacuated | 0.0 |
| Incident Identified Datetime | 2021-11-21 17:14:00 |
| Communication State Fed Ind | No |
| On Site Datetime | 2021-11-21 17:44:00 |
| Federal | No |
| Location Type | Operator-Controlled Property |
| Incident Area Type | Underground |
| Incident Area Subtype | Under Soil |
| Depth Of Cover | 40.0 |
| Other Underground Facilities | No |
| Crossing | No |
| Pipe Facility Type | Municipally Owned |
| System Part Involved | Main |
| Installation Year | 2019.0 |
| Pipe Diameter | 8.0 |
| Pipe Specification | Astm D2513 |
| Pipe Manufacturer | Performance Pipe |
| Material Involved | Plastic |
| Plastic Type | Polyethylene (Pe) |
| Plastic Sdr | 11 |
| Material Pe Pipe Code | 3408 |
| Release Type | Rupture |
| Rupture Orient | Other |
| Rupture Details | Spiral |
| Rupture Length | 120 |
| Rupture Width | 0.5 |
| Class Location Type | Class 2 Location |
| Est Cost Oper Paid | 10000.0 |
| Est Cost Prop Damage | 32000.0 |
| Est Cost Emergency | 25000.0 |
| Est Cost Other | 0.0 |
| Gas Cost In Mcf | 11.704 |
| Est Cost Unintentional Release | 6543.0 |
| Est Cost Intentional Release | 0.0 |
| Prpty | 73543.0 |
| Commercial Affected | 91.0 |
| Industrial Affected | 0.0 |
| Residences Affected | 48.0 |
| Num Persons Hosp Not Ovnght | 0.0 |
| Num Injured Treated By Emt | 0.0 |
| Num Resident Building Affctd | 144.0 |
| Num Business Building Affctd | 91.0 |
| Accident Psig | 62.0 |
| Normal Psig | 55.0 |
| Mop Psig | 60.0 |
| Mop Cfr Section | 192.621 M View CFR 49 §192 |
| Maop Established Date | 1998-06-01 00:00:00 |
| Accident Pressure | Pressure Exceeded Maop, But Did Not Exceed The Applicable Allowance In 192.201 |
| Gas Odorized System Type | Injection Pump |
| Gas Odorized Lvl Not Msrd Ind | Yes |
| Scada In Place Ind | Yes |
| Scada Operating Ind | Yes |
| Scada Functional Ind | No |
| 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 | Yes, specify investigation result(s): (select all that apply) |
| Invest Incorrect Action Ind | Yes |
| Invest Incorrect Procedure Ind | Yes |
| Invest Incorrect Control Ind | Yes |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Incorrect Operation |
| Cause Details | Valve Left Or Placed In Wrong Position, But Not Resulting In An Overpressure |
| Operation Type | Valve Left Or Placed In Wrong Position, But Not Resulting In An Overpressure |
| Related Inadequate Proc Ind | Yes |
| Category Type | Non-Routine Operating Conditions (Abnormal Operations Or Emergencies) |
| Operator Qualification Ind | Yes |
| Qualified Individuals | Yes, They Were Qualified For The Task(S) |
| Eqf Control Releaf Ind | Yes |
| Io Not Installed Properly Ind | Yes |
| Io Inadequate Procedure Ind | Yes |
| Preparer Name | E*** W***** |
| Preparer Title | Mechanical Engineer |
| Preparer Email | E******@i**********.com |
| Preparer Telephone | 9074527111 |
| Preparer Fax | 9074578111 |
| Authorizer Name | D** B****** |
| Authorizer Title | General Manager |
| Authorizer Telephone | 9074527111 |
| Authorizer Email | D********@i**********.com |
| Narrative | The interior gas utility (igu) lng storage and vaporization site number 3 (ss3) in fairbanks, alaska sent cold gas and possibly lng to the distribution system. When the cold gas or lng entered the distribution system, it embrittled the 8' underground hdpe pipe, which subsequently ruptured in a section of piping within igu property. The highest recorded pressure downstream of the distribution regulators at ss3 was 62psig. At approximately 4:10pm on 11/21/2021, a temperature switch on the outlet of the vaporizer malfunctioned and closed a valve to stop the flow of lng through the vaporizer. With no lng to vaporize, the glycol heater turned off due to low demand. At about 4:55pm, an operator noticed that the flow of lng had stopped, and the distribution pressure was dropping. The operator opened the closed vaporizer valve via remote control. The operator did not notice that the boiler was not firing and did not monitor the site long enough to verify the system was stable and proper temperatures where being maintained. Due to the malfunctioning temperature switch and a temperature transmitter that had not been programmed to act as a backup to the temperature switch, the control system did not stop the flow of lng through the vaporizer, upon a low gas temperature on the outlet of the vaporizer. The boiler attempted to fire about three minutes after the lng flow resumed but failed to stay running. The system attempted to start a back-up boiler about 10 minutes later, about when the distribution line ruptured. The standard operating procedures will be revised to no longer allow control changes from via remote control (except for emergency shut downs and specified exceptions) and instead require the monitoring operator to travel to the site to make the necessary adjustments and changes. The vaporizer temperature switches will be recommissioned, and the temperature transmitters will be added into the vaporizer shutdown programming logic to add redundancy. Additionally, a downstream temperature transmitter located on the meter skid will be used to shut down the lng pumps if low temperature is detected indicating the vaporizer shutdowns failed to activate as a result of low outlet temperature. |
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