Part 21 Report - 1997-492
ACCESSION #: 9707280078
United States
Enrichment Corporation
2 Democracy Center
6903 Rockledge Drive
Bethesda, MD 20817
USEC Tel: (301) 564-3200
Fax: (301) 564-3201
United States
Enrichment Corporation
GEORGE P. RIFAKES Dir: (301) 564-3301
EXECUTIVE VICE PRESIDENT, OPERATIONS Fax: (301) 571-8279
July 24, 1997
SERIAL: GDP 97-0117
U.S. Nuclear Regulatory Commission
Attention: Document Control Desk
Washington, D.C. 20555-0001
Portsmouth Gaseous Diffusion Plant (PORTS)
Docket No. 70-7002
Written Notification of 10 CFR 21 Report
The purpose of this letter is to provide written notification to the
Nuclear Regulatory Commission (NRC) in accordance with 10 CFR 21.21
(d)(3)(ii) of a reportable defect that has been identified at the
Portsmouth Gaseous Diffusion Plant (PORTS). The Initial Notification of
this defect was provided to the NRC by USEC letter GDP 97-0106, dated
June 24, 1997. The defect is associated with Release 21.1 of the STAAD-
III structural analysis program supplied by Research Engineers, Inc.,
22700 Savi Ranch, Yorba Linda, California, 92887-4608. This program is
being used to evaluate the existing crane support structure at the X-326
ERP Withdrawal Station as part of an ongoing project to replace the
existing liquid UF sub 6 handling crane at this location.
A defect was identified in Release 21.1 of the STAAD-III program
which yielded non-conservative results. The nature of the defect was an
error in one of the load specifications in Revision 21.1 that does not
recognize a concentrated member load when it is applied to the weak axis
of a member using a global direction specification. This defect could
have created, or contributed to, a substantial safety hazard. Non-
conservative design of the crane support structure could increase the
potential for dropping a cylinder containing liquid UF sub 6. The defect
was identified on April 25, 1997, during a review of STAAD-III output
calculations.
Release 21.1 of STAAD-III was received by PORTS in May of 1996, and
had been used in nine design applications at PORTS besides the crane
design discussed above. A review of each of these designs indicated that
none of them involved the load specification which exhibited the software
defect. Therefore, these other applications are not affected by this
defect.
Offices in Paducah, Kentucky Portsmouth, Ohio Washington, DC
U.S. Nuclear Regulatory Commission
Attn: Document Control Desk
July 24, 1997
GDP 97-0117, Page 2
The defect described above does not appear to exist in STAAD-III,
Releases 20 and 22 as determined by tests performed at PORTS (Release 20
had been used in previous design applications and Release 22 is being
used currently). Release 21.1 was not used to complete the crane support
structure design and has not been used on any other application since the
defect was discovered. No further corrective action is required to
resolve this issue.
The Paducah Gaseous Diffusion Plant has been apprised of this
situation.
No new commitments are made in this letter. Any questions related
to this subject should be directed to Mark Lombard at (301) 564-3248.
Sincerely,
George P. Rifakes
Executive Vice President, Operations
cc: NRC Region III Office
NRC Resident Inspector - PGDP
NRC Resident Inspector - PORTS
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