Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
ACCESSION #: 9712240055
Coltec Industries Fairbanks Morse
Engine Division
701 White Avenue
Beloit, WI 53511-5492
608/364-4411
FAX: 608/364-0382
INTERIM LETTER
Supplement No.: 97-002-01
To: Document Control Desk
U.S. Nuclear Regulatory Commission
Washington, DC. 20555
From: Coltec Industries-Fairbanks Morse Engine Division (FMED)
Date: 18 December 1997
Subject: Weldments on Opposed Piston and Coltec-Pielstick Emergency
Stand-By Diesel Gen-Set Lube-Oil and Jacket Water Piping Systems
This supplement to the Interim Letter dated 30 September 1997 is intended
to inform the U. S. Nuclear Regulatory Commission and the affected
nuclear utilities on the status of the root cause investigation and
corrective/preventive actions associated with the Coltec-FMED Part 21
File No.: 97-002.
The initial interim letter posed six (6) questions that formed the basis
of the root cause investigation.
Question 1: Is the weld design compliant with customer requirements?
Response: Customer contract requirements are currently under review by
our After-Market Parts Department. Three (3) general categories apply
the affected customers: 1) non specific design/fabrication requirement,
thus Coltec-FMED standards apply, 2) ANSI B31.1, and 3) ASME III, Class
3. Coltec-FMED will continue to review customer requirements as part of
the ongoing investigation.
Question 2: Are the subject welds compliant with FMED design
requirements?
Response: Sections of Lube-Oil and Jacket Water piping were submitted to
Coltec-FMED by Florida Power Corp., Baltimore Gas Electric, Virginia
Power, and Carolina Power & Light. Of the welds examined to date, most
do not have full penetration and therefore do not technically meet the FM
welding design requirements. However, several welds examined do have
full penetration through some portion of the joint.
A division of Coltec Industries Inc
Question 3: If not, do the existing welds posses sufficient strength?
Response: An Engineering procedure is developed and approved; however,
weld strength is yet to be determined by testing joints by means of a
burst test (pressurizing the piping, including the weld joint, to a high
pressure to see if the weld breaks and at what pressure-strength level).
Materials and set-up are necessary for this test process; they are
currently being gathered and organized.
Question 4: What is the root cause of the identified condition?
Response: The most likely root cause of incomplete penetration is a lack
of adequate instruction to the welders or welding operators to assure
that proper welds were obtained. This would include instruction on
preparation of the weld joint, weld gap requirements, and attention to
detail on the part of the welder to see that full penetration was
obtained. Moreover, lack of proper instruction to inspectors regarding
inspection of the finished welds must also be included as part of the
root cause. While some welds may be difficult to inspect directly, there
are sufficient methods available that allow welds either to be inspected
indirectly, or serially as the piping is assembled
Question 5: What corrective action, if any, should the customer take?
Response: Corrective action by the customer is dependent upon the burst
test results (ref. Question 3). If weld joints are generally found
unacceptable, then the customer should replace the affected piping with
property welded pipe. If; however, the present piping is generally found
strong enough as a result of satisfactory burst tests, no further action
is required.
Question 6: what preventive action is required by FMED?
Response: Design engineers should be instructed regarding proper design
and symbology of welds to best obtain full penetration, including design
details on drawings that outline weld joint preparation (taper of inside
diameters on standard fittings where weld joints include welding to thin
wall mechanical tube, etc).
Welders/weld operators must be instructed regarding requirements for full
penetration welding, including operator/welder qualification. Proper
weld joint preparation must be emphasized.
Inspectors must be instructed regarding proper methods to ensure welds
are properly made to design requirements, including full penetration
without excessive weld material on the inside diameter of the pipe.
The above corrective actions should be extended to commercial fabrication
as well.
Results from the burst test should be available by the end of January
1998, at which time the review of customer contract requirements should
also be complete. A final letter of notification should be available by
the end of February 1998.
Sincerely,
Scott A. Fratianne
Sr. Quality Assurance Engineer
Paul Danyluk
Vice President, Engineering
cc: M. Armfield
T. Gill
B. Hall
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