ML20149J156
| ML20149J156 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant |
| Issue date: | 07/24/1997 |
| From: | Rifakes G UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| REF-PT21-97 GDP-97-0117, GDP-97-117, NUDOCS 9707280078 | |
| Download: ML20149J156 (2) | |
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Enrichment Corporition 2 Democracy Center 6903 Rockledge Dnve INthesda, MD 20817 Tel. (301) 564-3200 Fax: (301) 564-3201 United Sales lGirichment Corl oration GEORGE P. RlFAKES 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, Califomia,92887-M08. 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 l)
UF, handling crane at this location.
t 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 gb 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 UFe The defect was identified on April 25,1997, during a review of STAAD-111 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 application: are not affected by this defect.
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hv '. u 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.lwas 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, f'
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George. Rifakes Executive Vice President, Operations e
cc: NRC Region III Oflice NRC Resident Inspector - PGDP NRC Resident Inspector - PORTS i
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