Information Notice No. 91-25: Commercial-Grade Structural Framing Components Supplied as Nuclear Safety-Related Equipment
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555
April 1, 1991
Information Notice No. 91-25: COMMERCIAL-GRADE STRUCTURAL FRAMING
COMPONENTS SUPPLIED AS NUCLEAR
SAFETY-RELATED EQUIPMENT
Addressees:
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose:
This information notice is intended to alert licensees to problems in the
dedication of structural framing components supplied to the nuclear industry
by the Unistrut Corporation (UC), Wayne, Michigan. It is expected that
recipients will review this information for applicability to their
facilities and consider actions, as appropriate, to avoid similar problems.
However, suggestions contained in this information notice do not constitute
NRC requirements; therefore, no specific action or written response is
required.
Description of Circumstances:
The most common structural framing components supplied to licensees by UC
are 1-5/8-inch wide, continuously slotted, structural framing channel
members; fasteners; and mechanical accessories such as channel nuts,
fittings, and pipe clamps. These components are supplied through a network
of nationwide Authorized Service Centers, some of which are owned and
operated by UC.
The NRC inspected the UC facilities and records and found that UC had failed
to implement measures to control the dedication of commercial-grade
structural framing components. UC supplied Certificates of Conformances
(COCs) stating that these materials met the requirements of Appendix B to
Part 50 of Title 10 of the Code of Federal Regulations (10 CFR) and were
supplied in accordance with the provisions of 10 CFR Part 21. UC failed to
demonstrate that it had: (1) established an adequate basis for accepting
material certifications from its suppliers of fasteners and coil material,
(2) verified the chemical and physical properties of coil material, (3)
performed destructive product testing traceable to each coil of material
used to manufacture structural framing channel, (4) maintained traceability
of the material used to manufacture mechanical accessories, or (5) performed
adequate product testing on all mechanical accessories.
UC manufactures structural framing channel members from coil material
procured to UC's material specifications from various commercial-grade
suppliers and manufacturers. These suppliers provided material
certifications that UC
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April 1, 1991
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accepted without assuring that the coil materials could be traced and
identified to the certifications. UC did not perform a destructive product
test on structural framing channel that was traceable to each heat or lot of
coil material. Furthermore, UC did not perform tests or examinations to
ensure the accuracy of the chemical and physical properties listed in the
material certifications. UC supplied the commercial-grade structural
framing channel to licensees as safety-related components that comply with
the requirements of the American Society for Testing and Materials (ASTM)
Standards, Appendix B to 10 CFR Part 50, and 10 CFR Part 21 with COCs
stating that these requirements were met, even though UC did not perform an
adequate commercial-grade dedication of the coil material. In some
instances, UC also certified that the channel met the requirements of the
American Society of Mechanical Engineers, Boiler and Pressure Vessel Code
(ASME Code), Section III, Class 2, Subsection NF-2600 but did not
demonstrate compliance with the ASME Code requirements.
All fasteners supplied by UC were procured as commercial-grade items from a
single supplier (General Fastener Company of Livonia, Michigan), which
furnished machine screws, nuts, and washers that were 1/2-inch and smaller.
UC procured these fasteners according to the Society of Automotive Engineers
(SAE) Standards and supplied them to licensees as safety-related fasteners
that comply with the requirements of the ASTM Standards, Appendix B to
10 CFR Part 50, and 10 CFR Part 21 with COCs stating these requirements were
met, even though UC did not perform any commercial-grade dedication
activities.
Mechanical accessories are also manufactured by UC from coil material
procured to UC's material specifications from various commercial-grade
suppliers and manufacturers. These suppliers provided material
certifications that UC accepted without assuring that the coil materials
could be traced and identified to the certifications. Channel nuts and
90-degree angle fittings are the only mechanical accessories that receive
product tests. UC also did not perform tests or examinations to ensure the
accuracy of the chemical and physical properties listed in the material
certifications. UC supplied the mechanical accessories to licensees as
safety-related components that comply with the requirements of ASTM
Standards, Appendix B to 10 CFR Part 50, and 10 CFR Part 21 with COCs
stating these requirements were met, even though UC did not perform an
adequate commercial-grade dedication of the coil material.
Licensees have conducted numerous audits of UC and some have placed UC on
their approved vendor lists to supply safety-related components. The
inspectors examined sample audit conclusions and found that they varied
widely. Some licensees found that UC was fully capable of supplying
safety-related components that comply with the requirements of Appendix B to
10 CFR Part 50 and 10 CFR Part 21, and in one instance found that UC could
supply safety-related components that comply with the ASME Code
requirements. Other licensees found that UC could only supply
commercial-grade components. In performing many of the audits, licensees
did not identify UC's failure to implement adequate measures to control the
dedication of commercial-grade structural framing components, indicating a
significant weakness in the performance of these audits.
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Discussion:
UC manufactures structural framing components used to support nonsafety and
safety-related components such as pipes, instrument lines, ducts, cable
trays, and conduits. The NRC has not identified a significant safety
concern or in-service failure regarding the known applications of these
structural framing components. However, structural framing components were
supplied by UC as safety-related and may be installed in safety-related
structures, systems, or components and may not meet quality standards
commensurate with the importance of the safety function to be performed.
Therefore, licensees may wish to review their use of structural framing
components to confirm that the procured equipment is acceptable. In
addition, licensees may wish to examine the adequacy of applicable audits
and their audit process.
This information notice requires no specific action or written response. If
you have any questions about this matter, please contact one of the
technical contacts listed below or the appropriate NRR project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts: Steven M. Matthews, NRR
(301) 492-3191
Stewart L. Magruder, NRR
(301) 492-3220
Attachment: List of Recently Issued NRC Information Notices
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