NTSB Safety Recommendation P-86-015

NTSB safety recommendation P-86-015.

THE NTSB RECOMMENDS THAT THE RESEARCH AND SPECIAL PROGRAMS ADMINISTRATION: AMEND FINAL ORDER CPF NO. 3541-H TO WILLIAMS PIPE LINE COMPANY: (1) TO REQUIRE THE DEVELOPMENT AND THE SUBMISSION TO THE RESEARCH AND SPECIAL PROGRAMS ADMINISTRATION FOR ITS APPROVAL OF A PLAN FOR TESTING LINE 2N THAT INCORPORATES THE FINDINGS OF RESEARCH INTO THE PRESSURE REVERSAL PHENOMENON AND THAT INCLUDES A TEST PRESSURE LEVEL CAPABLE OF ELIMINATING POTENTIALLY HARMFUL DEFECTS; (2) TO REQUIRE METALLURGICAL TESTING OF ALL SEAM FAILURES UNLESS THE FAILURE MECHANISM IS DETERMINED VISUALLY BY AN INDEPENDENT METALLURGIST; AND (3) TO ESTABLISH A MAXIMUM ALLOWABLE OPERATING PRESSURE BASED ON THE RESULTS OF THE TESTS. (URGENT)

Priority: CLASS I

Overall Status: Closed - Acceptable Action

Issued Date: 1986-08-13

Adopted Date: 1986-08-13

Overall Date Closed: 1993-05-11

Synopsis: ABOUT 4:20 A.M. ON JULY 8, 1986, LINE 2N, AN 8-INCH PRODUCTS PIPELINE AT MOUNDS VIEW, MINNESOTA, OPERATED BY WILLIAMS PIPE LINE COMPANY (WPL) RUPTURED. UNLEADED GASOLINE UNDER ABOUT 1,480 PSIG SPEWED FROM THE 7 1/2-FOOT-LONG OPENING ALONG THE LONGITUDINAL SEAM OF THE PIPE. VAPORIZED GASOLINE COMBINED WITH THE AIR, AND LIQUID GASOLINE FLOWED ALONG NEIGHBORHOOD STREETS. ABOUT 20 MINUTES LATER, THE GASOLINE VAPOR WAS IGNITED BY SPARKS FROM AN AUTOMOBILE WHICH HAD ENTERED THE AREA. FOLLOWING AN EXPLOSION-LIKE NOISE, FIRE SPREAD RAPIDLY THROUGH THE NEIGHBORHOOD ALONG THE PATH OF LIQUID GASOLINE. TWO PERSONS WERE BURNED SEVERELY AND LATER DIED, AND ONE PERSON SUFFERED SERIOUS BURNS. THERE WAS SUBSTANTIAL PROPERTY DAMAGE AND SOIL AND WATER POLLUTION.

Ntsbnumber: DCA86AP014

Report Number: PAR-87-02

Addressee Name: RSPA

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1993-05-11

Addressee Acronym: RSPA

Addressee Organization Type: G-Federal Government

Communication Date: 1993-05-11

Communication Type: Official Correspondence

Communication Contents: THE BOARD HAS REVIEWED THE OPERATIONAL RELIABILITY ANALYSIS THAT WAS SUBMITTED TO RSPA BY THE WILLIAMS PIPE LINE COMPANY & DETERMINED THAT RSPA HAS ACCOMPLISHED THE THREE OBJECTIVES OF P-86-15. THIS ANALYSIS INCLUDED HYDROSTATIC TESTING, METALLURGICAL EXAMINATIONS, DETERMINATION OF A MAXIMUM ALLOWABLE OPERATING PRESSURE, & OTHER INTERNAL SURVEYS. BASED ON THIS INFO, P-86-15 HAS BEEN CLASSIFIED "CLOSED--ACCEPTABLE ACTION."

Addressee Acronym: RSPA

Addressee Organization Type: G-Federal Government

Communication Date: 1986-09-18

Communication Type: Official Correspondence

Communication Contents: ON JULY 11, THE OFFICE OF PIPELINE SAFETY (OPS) ISSUED A HAZARDOUS FACILITY ORDER PREVENTING THE WILLIAMS PIPE LINE CO. FROM RETURNING THE MOUNDS VIEW/DULUTH PIPELINE TO OPERATION UNTIL A SERIES OF STEPS WERE TAKEN, REQUIRING WILLIAMS TO TAKE AT LEAST 2 TO 3 MONTHS TO COMPLETE; AND THE PIPELINE MUST PASS ALL REQUIRED TESTS. DESPITE THIS, YOU CLASSIFIED THE RECOMMENDATION AS "URGENT - PRIORITY ACTION." THE IMMINENT RISK TO THE PUBLIC HAD BEEN ADDRESSED & RESOLVED BY THE VERY ISSUANCE OF DOT'S ORDER. FURTHERMORE, IN A LETTER TO THE CITY OF MOUNDS VIEW, DATED AUGUST 6, WE PROVIDED A DETAILED EXPLANATION OF THE ORDER, CLARIFIED THE ISSUES RAISED BY THE CITY, AND DISCUSSED TESTING PLANS INCLUDING AN OPERATIONAL RELIABILITY ASSESSMENT (ORA), WHICH WOULD BE UNDERTAKEN TO ENHANCE THE MARGIN OF SAFETY ALONG THE ENTIRE LENGTH OF THE PIPELINE. WE KEPT YOUR STAFF FULLY INFORMED OF KEY DELIBERATIONS IN THIS PROCESS AND A COPY OF THE AUGUST LETTER TO MOUNDS VIEW AS HAND DELIVERED TO THE NTSB THE NEXT DAY. UNFORTUNATELY, P-86-15 REFERS TO THE PRESSURE REVERSAL PHENOMENON IN A WAY WHICH IMPLIES THAT WE DID NOT TAKE THIS PHENOMENON INTO CONSIDERATION IN ISSUING OUR HAZARDOUS FACILITY ORDER. LET ME CORRECT THIS MISCONCEPTION: IT IS PRECISELY BECAUSE OF OUR UNDERSTANDING OF PRESSURE REVERSALS THAT WE CHOSE THE PRESSURE LEVELS DESIGNATED IN THE ORDER. THE DIFFERENCE BETWEEN THESE PRESSURE LEVELS ASSURES MORE THAN A 99.9 DEGREE OF CERTAINTY THAT A PRESSURE REVERSAL WILL NOT OCCUR. PRESSURE REVERSAL IS A PHENOMENON USUALLY ASSOCIATED WITH SUBCRITICAL CRACK GROWTH IN THE PLASTIC REGIME OF MATERIAL BEHAVIOR, AND GENERALLY OCCURS IMMEDIATELY UPON REPRESSURING A PIPE TO ITS OPERATING PRESSURE FOLLOWING HYDROSTATIC TEST WHICH HAS BEEN RUN AT A HIGHER PRESSURE. THE NTSB THEN RECOMMENDED A TEST PRESSURE OF 2200 PSIG, WHICH YOU CORRECTLY EQUATE WITH A STRESS LEVEL EQUAL TO 90 PERCENT OF THE SPECIFIED MINIMUM YIELD OF STRENGTH (SMYS) OF THE PIPE. YOU IMPLIED THAT COMPANIES NORMALLY TEST AT 90 PERCENT OF SMYS FOR SAFETY REASONS. AGAIN, THERE IS A MISUNDERSTANDING. THE REASON FOR TESTING AT 2200 PSIG IS TO ENABLE THE LINE TO BE OPERATED AT A MAXIMUM ALLOWABLE OPERATING PRESSURE (MAOP) SUCH AS 1700 TO 1800 PSIG. IT IS BECAUSE OF THE DESIRE TO ACHIEVE HIGH MAOP LEVELS THAT PIPELINE COMPANIES TEST AT 90 PERCENT OF SMYS AND NOT FOR "ELIMINATING POTENTIAL MATERIAL DEFECTS" AS STATED IN YOUR RECOMMENDATION. THEREFORE, IN ORDER TO ATTAIN THE GREATEST MARGIN OF SAFETY, THE MOST IMPORTANT PARAMETER IS THE MARGIN OR DIFFERENCE BETWEEN AN OPTIMUM TEST PRESSURE LEVEL AND AN OPERATING PRESSURE LEVEL. ON 8/18/86, DR. ROBERT PAULLIN, MR. ED ONDAK AND I MET WITH OFFICIALS OF THE CITY OF MOUNDS VIEW TO DISCUSS AMENDMENTS TO THE HAZARDOUS FACILITY ORDER. DR. PAULLIN AND THE CITY MUTUALLY AGREED TO CERTAIN AMENDMENTS TO THE ORDER. I HAVE ENCLOSED A COPY OF THE AUGUST 22, 1986, AMENDED ORDER (DELIVERED TO YOU ON AUGUST 25, 1986.)

Addressee Acronym: RSPA

Addressee Organization Type: G-Federal Government

Communication Date: 1992-09-02

Communication Type: Official Correspondence

Communication Contents: ON DECEMBER 10, 1990, RSPA WROTE TO NTSB RECOMMENDING THAT P-87-25 BE CLOSED. ON JUNE 5, 1991, NTSB CLOSED P-87-25 AS AN ACCEPTABLE ACTION STATING THT WILLIAMS HAS IMPLEMENTED BOTH A COMPUTER-BASED SYSTEM TO MONITOR AND CONTROL THE PIPELINE SYSTEM WITH LEAK DETECTION CAPABILITIES AND A COMPUTER-BASED SYSTEM TO MONITOR AND CONTROL THE PIPELINE SYSTEM WITH LEAK DETECTION CAPABILITIES AND A COMPUTER-BASED DATA MANAGEMENT SYSTEM TO FACILITATE INTERPRETATION OF CATHODIC PROTECTION DATA. ACCORDINGLY, WE BELIEVE RECOMMENDATION P-86-15 SHOULD ALSO BE CLOSED.

Addressee Acronym: RSPA

Addressee Organization Type: G-Federal Government

Communication Date: 1986-11-17

Communication Type: Official Correspondence

Addressee Acronym: RSPA

Addressee Organization Type: G-Federal Government

Communication Date: 1990-12-10

Communication Type: Official Correspondence

Addressee Acronym: RSPA

Addressee Organization Type: G-Federal Government

Communication Date: 1992-08-31

Communication Type: Official Correspondence