NTSB Safety Recommendation P-82-036

NTSB safety recommendation P-82-036.

THE NTSB RECOMMENDS THAT THE MISSOURI POWER AND LIGHT COMPANY: INSTALL EQUIPMENT TO TRANSMIT GAS PRESSURE OR GAS FLOW DATA FROM DISTRICT REGULATOR STATIONS IN CENTRALIA TO THE DISPATCHER AT MOBERLY, MISSOURI, WITH ALARMS TO ALERT THE DISPATCHERS IN THE EVENT OF ABNORMAL GAS FLOW RATES OR PRESSURES.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1982-09-08

Adopted Date: 1982-08-24

Overall Date Closed: 1995-05-25

Synopsis: ON JANUARY 28, 1982, AT CENTRALIA, MISSOURI, NATURAL GAS AT 47 PSIG ENTERED A LOW PRESSURE DISTRIBUTION SYSTEM WHICH NORMALLY OPERATED AT 11 INCHES WATER COLUMN (0.40 PSIG) AFTER A BACKHOE BUCKET SNAGGED, RUPTURED, AND SEPARATED THE 3/4-INCH-DIAMETER STEEL PRESSURE REGULATOR CONTROL LINE AT THE MISSOURI POWER AND LIGHT COMPANY'S DISTRICT REGULATOR STATION NO. 1. THE BACKHOE, WHICH WAS OWNED AND OPERATED BY THE CITY OF CENTRALIA, WAS BEING USED TO CLEAN A DITCH LOCATED ADJACENT TO THE PRESSURE REGULATOR STATION. THE HIGH PRESSURE GAS ENTERING CUSTOMER PIPING SYSTEMS IN SOME CASES RESULTED IN HIGH PILOT LIGHT FLAMES WHICH INITIATED FIRES IN BUILDINGS; WHILE IN OTHER CASES, THE PILOT LIGHT FLAMES WERE BLOWN OUT, ALLOWING GAS TO ESCAPE WITHIN THE BUILDINGS. OF THE 167 BUILDINGS AFFECTED BY THE OVER PRESSURE, 12 WERE DESTROYED AND 32 SUSTAINED MODERATE TO HEAVY DAMAGES. FIVE PERSONS RECEIVED MINOR INJURIES.

Probable Cause: None

Ntsbnumber: DCA82MP010

Report Number: PAR-82-03

Addressee Name: Missouri Power and Light Company

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1995-05-25

Addressee Organization Type: P-Private Industry

Communication Date: 1982-10-07

Communication Type: Official Correspondence

Communication Contents: MISSOURI POWER AND LIGHT COMPANY LETTER: WE WILL INVESTIGATE THE FEASIBILITY OF FURTHER TELEMETERING EQUIPMENT WITH ALARMS BEING INSTALLED IN THE ELECTRICAL LOAD DISPATCHING OFFICE IN MOBERLY. WE WILL ALSO CONSULT WITH THE MISSOURI PUBLIC SERVICE COMMISSION REGARDING THE EXPENDITURES NECESSARY FOR THE IMPLEMENTATION OF SUCH A SYSTEM.

Addressee Organization Type: P-Private Industry

Communication Date: 1995-02-13

Communication Type: Official Correspondence

Communication Contents: UNION ELECTRIC COMPLETED IT STUDY IN ABOUT 1985 & INSTALLED A SYSTEM WITH ALARMS THROUGH WHICH GAS FLOW DATA FOR ITS LARGER GAS SERVICE COMMUNITIES (INCLUDING CENTRALIA) IS TRANSMITTED TO ITS DISPATCH OFFICE. THE DISPATCH OFFICE, WHICH WAS LOCATED IN MOBERLY, HAS BEEN MOVED TO JEFFERSON CITY, MISSOURI.

Addressee Organization Type: P-Private Industry

Communication Date: 1983-02-16

Communication Type: Official Correspondence

Communication Contents: The Board has accepted your commitment to study the feasibility of further data transmission equipment as a beginning to fulfilling the need described in P-82-36. We will hold this recommendation in an “Open-Acceptable Action” status pending further reports on the progress of the study. Thank you for your cooperation and efforts toward implementing our pipeline Safety Recommendations.

Addressee Organization Type: P-Private Industry

Communication Date: 1995-05-25

Communication Type: Official Correspondence

Communication Contents: THE BOARD NOTES THAT UNION ELECTRIC COMPLETED A FEASIBILITY STUDY ON THIS ISSUE IN 1985 & INSTALLED AN ALARM SYSTEM TO ALERT THE DISPATCH OFFICE OF ABNORMAL GAS FLOW RATES. BASED ON THIS INFORMATION P-82-36 HAS BEEN CLASSIFIED "CLOSED--ACCEPTABLE ACTION."