NTSB Safety Recommendation P-98-015

NTSB safety recommendation P-98-015.

THE NTSB RECOMMENDS THAT THE MIDAMERICAN ENERGY CORPORATION: AS A BASIS FOR THE TIMELY REPLACEMENT OF YOUR PLASTIC PIPING SYSTEMS THAT INDICATE UNACCEPTABLE PERFORMANCE, REVIEW YOUR EXISTING PLASTIC PIPING SURVEILLANCE & ANALYSIS PROGRAM & MAKE THE CHANGES NECESSARY TO ENSURE THAT THE PROGRAM IS BASED ON SUFFICIENTLY PRECISE FACTORS SUCH AS PIPING MANUFACTURER, INSTALLATION DATE, PIPE DIAMETER, GEOGRAPHICAL LOCATION, & CONDITIONS & LOCATIONS OF FAILURES.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1998-04-30

Adopted Date: 1998-04-23

Overall Date Closed: 1999-04-07

Synopsis: DESPITE THE GENERAL ACCEPTANCE OF PLASTIC PIPING AS A SAFE & ECONOMICAL ALTERNATIVE TO PIPING MADE OF STEEL OR OTHER MATERIALS, THE BOARD NOTES THAT A NUMBER OF PIPELINE ACCIDENTS IT HAS INVESTIGATED HAVE INVOLVED PLASTIC PIPING THAT CRACKED IN A BRITTLE-LIKE MANNER. FOR EXAMPLE, ON 10/17/94, AN EXPLOSION & FIRE IN WATERLOO, IOWA, DESTROYED A BUILDING & DAMAGED OTHER PROPERTY. SIX PERSONS DIED & SEVEN WERE INJURED IN THE ACCIDENT. THE BOARD INVESTIGATION DETERMINED THAT NATURAL GAS HAS BEEN RELEASED FROM A PLASTIC SERVICE PIPE THAT HAD FAILED IN A BRITTLE-LIKE MANNER AT A CONNECTION TO A STEEL MAIN.

Probable Cause: None

Ntsbnumber: DCA95MP001

Report Number: SIR-98-01

Addressee Name: MidAmerican Energy Corporation

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1999-04-07

Addressee Organization Type: P-Private Industry

Communication Date: 1998-06-10

Communication Type: Official Correspondence

Communication Contents: (Letter Mail Controlled 6/15/98 3:24:12 PM MC# 980766) MIDAMERICAN HAS EVALUATED EACH OF THE BOARD'S LISTED PARAMETERS & WILL INCLUDE THOSE THAT MIDAMERICAN DETERMINES ARE APPROPRIATE FOR ITS PIPELINE SYSTEM.

Addressee Organization Type: P-Private Industry

Communication Date: 1999-02-09

Communication Type: Official Correspondence

Communication Contents: Letter Mail Controlled 2/12/99 3:00:46 PM MC# 990142 MIDAMERICAN HAS MADE SIGNIFICANT CHANGES TO THE METHODS USED TO MONITOR PLASTIC SYSTEMS. ALL FAILED PLASTIC MATERIALS ARE SENT TO THE STANDARDS DEPARTMENT FOR EVALUATION AND RETAINED FOR TWENTY YEARS. MIDAMERICAN'S NEW MATERIAL FAILURE REPORT INCLUDES MANUFACTURER, PART DESCRIPTION, INSTALLATION DATE, FAILURE DISCOVERY DATE, STREET ADDRESS, TOWN, OPERATING PRESSURE, FACILITY TYPE (MAIN, SERVICE, ETC.), PIPE SIZE, LOCATION OF FAILURE (LAWN, PAVED STREET, PARKING, ETC.), AND OBSERVED CONTRIBUTING FACTORS (GOUGES, OVER-PRESSURIZATION, DIMENSION OUT OF TOLERANCE, IMPROPER INSTALLATION, HARMFUL MATERIALS IN CONTACT WITH PIPE, SHEAR FORCES, EXTERNAL LOADING, ETC.). THE NEW PROGRAM IS FULLY DOCUMENTED IN WRITING, APPROVED BY STANDARDS COMMITTEE. FIELD TRAINING IS CURRENTLY BEING CONDUCTED. MIDAMERICAN ENERGY REQUESTS THAT THE NTSB CLASSIFY P-98-15 AS CLOSED.

Addressee Organization Type: P-Private Industry

Communication Date: 1998-07-23

Communication Type: Official Correspondence

Communication Contents: THE BOARD AGREES THAT GAS SYSTEM OPERATORS HAD INSUFFICIENT NOTIFICATION FROM MANUFACTURERS, THE INDUSTRY, & REGULATORS OF POORLY PERFORMING BRANDS OF PE 2306 PIPING & THUS MAY NOT HAVE REALIZED THE IMPORTANCE OF CHOOSING SPECIFICALLY PRECISE PARAMETERS TO IDENTIFY THOSE PORTIONS OF ITS PLASTIC PIPING SYSTEMS THAT INDICATE UNACCEPTABLE PERFORMANCE. THE BOARD IS PLEASED WITH MIDAMERICAN , ACCORDINGLY, P-98-15 HAS BEEN CLASSIFIED "OPEN--ACCEPTABLE RESPONSE," PENDING INCORPORATION OF SUFFICIENTLY PRECISE FACTORS INTO MIDAMERICAN'S SYSTEMS FOR TRACKING, IDENTIFYING, & STATISTICALLY CHARACTERIZING PLASTIC PIPING FAILURES.

Addressee Organization Type: P-Private Industry

Communication Date: 1999-04-07

Communication Type: Official Correspondence

Communication Contents: THE SAFETY BOARD NOTES THAT MIDAMERICAN HAS COMPLETED SIGNIFICANT CHANGES TO THE METHODS USED TO MONITOR PLASTIC SYSTEMS. IN ADDITION, THE NEW PROGRAM IS FULLY DOCUMENTED IN WRITING, HAS BEEN APPROVED BY THE MIDAMERICAN STANDARDS COMMITTEE, AND FIELD TRAINING IS BEING CONDUCTED. THEREFORE, P-98-15 HAS BEEN CLASSIFIED "CLOSED--ACCEPTABLE ACTION."