[Federal Register Volume 63, Number 77 (Wednesday, April 22, 1998)]
[Notices]
[Pages 19999-20000]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-10673]


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DEPARTMENT OF TRANSPORTATION

Research and Special Programs Administration
[Docket No. RSPA-98-3638; Notice 1]


Pipeline Safety: Liquefied Natural Gas Facilities Petition for 
Waiver; Exxon Company, USA

    Exxon Corporation has petitioned the Research and Special Programs 
Administration (RSPA) for a waiver from compliance with certain 
provisions of 49 CFR part 193 for its proposed Liquefied Natural Gas 
(LNG) storage tanks at its existing LaBarge, Wyoming, gas processing 
operation. The existing operation includes two parallel Nitrogen 
Rejection Units and a small liquefied natural gas (LNG) truck loading 
facility. Exxon is proposing to install two used 55,000 gallon LNG 
storage tanks (vessel nos. 5477 and 5516). According to Exxon, these 
tanks were in LNG service for 19 years without problems. The tanks were 
designed, built, tested, and registered in accordance with the 
requirements of the American Society of Mechanical Engineers (ASME) 
Boiler and Pressure Vessel Code, Section VIII, Division 1.
    Exxon states that as a part of the post fabrication procedures of 
the ASME Code, the longitudinal and circumferential butt welds of 
vessel number 5477 were spot checked by radiographic methods. The 
longitudinal and circumferential butt welds of vessel number 5516 were 
100 percent radiographically tested at the time of manufacture. The 
ASME Code does not apply to any piping beyond the first weld.
    Exxon requests a waiver from compliance with certain sections of 
Part 193 and proposes to ensure equivalent safety through compliance 
with the National Fire Protection Association (NAPA) Standard 59A. The 
specific sections of Part 193 for which Exxon seeks a waiver are:
    (1) Sec. 193.2321 (a)--Nondestructive tests. This section requires 
that 100 percent of circumferential butt welded pipe joints in 
cryogenic piping and 30 percent of circumferential butt welded pipe 
joints in the non-cryogenic piping be nondestructively tested.
    Exxon is requesting a waiver for vessels 5477 and 5516 of the 
requirements of Sec. 193.2321 (a)--Nondestructive tests, based on the 
following:
     Calculated value of the pressure induced hoop stresses for 
the inner vessel nozzles and interconnecting piping are less than the 
20 percent of the specified minimum yield stress (SMYS) for the piping 
material which is recognized as acceptable under NAPA 59A. To support 
this allegation Exxon has submitted stress calculations.
     NAPA 59A--Standard of the Production, Storage and Handling 
of Liquefied Natural Gas (LNG), section 6-6--Inspection and Testing of 
Pipe, Paragraph 6-6.3.2, requires all circumferential butt welds to be 
nondestructively tested, except that liquid drain and vapor vent piping 
with an operating pressure that produces a hoop stress of less than 20 
percent of SMYS need not be nondestructively tested, provided it has 
been inspected visually in accordance with the ASME standard B31.3--
Chemical Plant and Petroleum Refinery, section 344.2.
    RSPA believes that safety will not be compromised by waiving the 
requirements of Sec. 193.2321(a) for non-cryogenic piping with 
operating pressures that produce hoop stresses of less than 20 percent 
SMYS, if that piping complies with standard NAPA 59A, Section 6-6.3.2. 
Therefore, RSPA is proposing to grant the waiver from Sec. 193.2321(a).
    (2) Sec. 193.2321 (e)--Nondestructive tests. This section requires 
100 percent nondestructive tests of both longitudinal and 
circumferential butt welds in metal shells of storage tanks that are 
subject to cryogenic temperatures and are under pressure to be 
radiographically tested.
    Exxon requests a waiver of the requirements of Sec. 193.2321 (e)--
Nondestructive tests, for vessel number 5477 based on the following 
reasons:
     The tank was designed, manufactured, tested and registered 
to the requirements of the ASME Boiler and Pressure Vessel Code. 
Section VIII Division 1 of the ASME Code is an accepted standard to 
which cryogenic pressure vessels are built throughout the world.
     Safety in this case is not compromised because the storage 
tank at the Exxon facility is small, less than 70,000 gallons, shop 
fabricated and built to the ASME Code.
     Public safety is not the issue because the facility is 
very remote.

[[Page 20000]]

     The use of a weld joint efficiency factor of 85 percent 
and spot radiographic testing result in an inner vessel of thicker 
material than one built with a weld joint efficiency factor of 100 
percent and 100 percent radiograph testing, substantially reducing the 
stress in the welds.
     The tank meets NAPA 59A requirements under Section 4-2, 
Metal Containers, paragraph 4-2.2.2., which states that the inner tank 
must be welded construction in accordance with the ASME Code, Section 
VIII, and must be ASME-stamped and registered with the National Board 
of Boiler and Pressure Vessels Inspectors (NBBI) or other agency that 
registers pressure vessels.
    RSPA agrees that safety will not be compromised by waiving the 
requirements of Sec. 193.2321(e) for smaller pressure vessels (less 
than 70,000 gallons) that are designed and built to the ASME Code, 
Section VIII (greater than 15 psig). Tanks built to this code are shop-
fabricated under strict quality control and are inspected and stamped 
by Authorized Inspectors of the NBBI. Storage tanks at the Exxon 
LaBarge gas processing facility are built to ASME Code, Section VIII, 
and have a capacity of 55,000 gallons (relatively small). Therefore, 
RSPA is proposing to grant the waiver from Sec. 193.2321(e).
    (3) Sec. 193.2329(a)--Construction Records. This section requires 
that an operator shall retain records of specifications, procedures and 
drawings consistent with this part, and section 193.2329(b) requires 
that an operator must retain records of results of tests, inspections 
and quality assurance programs required by this subpart.
    Exxon states that the ASME-stamped nameplates and the ASME U-1 form 
constitute adequate records for vessel construction. However, Exxon 
requests a waiver of the requirements of Section 193.2329 because the 
vessels were built to the ASME Code as referenced in NAPA 59A. The 
operator further agrees to comply with the recordkeeping requirements 
in accordance with Sections 193.2329 (a) and (b).
    RSPA agrees and proposes to grant a waiver from sections 193.2329 
(a) and (b) for selected parts of the Exxon facility.
    Except for the sections for which RSPA is proposing to grant a 
waiver, this LNG facility must meet all the requirements of Part 193. 
RSPA believes that the granting a waiver would not be inconsistent with 
pipeline safety, as long as Exxon follows the alternative provisions in 
the NAPA 59A.
    Interested parties are invited to comment on the proposed waiver by 
submitting in duplicate such data, views, or arguments as they may 
desire. Comments should identify the Docket and Notice number (Docket 
no. RSPA-98-3638; Notice 1), and should be addressed to the Docket 
Facility, U.S. Department of Transportation, Plaza 401, 400 Seventh 
Street SW., Washington, DC 20590-0001. Alternatively, comments may be 
submitted via e-mail to ``[email protected]''.
    All comments received before May 22, 1998 will be considered before 
final action is taken. Late filed comments will be considered so far as 
practicable. No public hearing is contemplated, but one may be held at 
a time and place set in a notice in the Federal Register if requested 
by an interested person desiring to comment at a public hearing and 
raising a genuine issue. All comments and other docketed material will 
be available for inspection and copying in room Plaza 401 between the 
hours of 10:00 a.m. and 5 p.m., Monday through Friday, except federal 
holidays.

    Authority: 49 App. U.S.C. 2002(h) and 2015; and 49 CFR 1.53.

    Issued in Washington, D.C. on April 16, 1998.
Richard B. Felder,
Associate Administrator for Pipeline Safety.
[FR Doc. 98-10673 Filed 4-21-98; 8:45 am]
BILLING CODE 4910-60-P