PNO-IV-97-053, on 970917,Siemens Nuclear Corp Reported Discovery of Damp U Dioxide Matl in Transfer Line in Dry Conversion Pilot Facility Sample Analyses of Pyrohyrolysis Vessel.Licensee Rept Made,Per NRC Bulletin 91-001

PNO-IV-97-053:on 970917,Siemens Nuclear Corp Reported Discovery of Damp U Dioxide Matl in Transfer Line in Dry Conversion Pilot Facility Sample Analyses of Pyrohyrolysis Vessel.Licensee Rept Made,Per NRC Bulletin 91-001

ML20198H527
Person / Time
Site:	Framatome ANP Richland
Issue date:	09/18/1997
From:	Scarano R, Wenslawski F NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
References
IEB-91-001, IEB-91-1, PNO-IV-97-053, PNO-IV-97-53, NUDOCS 9709190023
Download: ML20198H527 (2)

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, 1- September 18,1997 PRELIMINARY _ NOTIFICATION OF EVENT OR UNUSUAL OCQURRENCE PNO IV 97 053 This prelirninary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially l received without verification or evaluation, and is basically all that is known by Region IV staff in Arlington, Tuos on this date.

Facility LicenstalmttatDE.Clapsification l Slemans Nuclear Power Corporation Notification of Unusual Event t

Siemens Nuclear Power Corporation Alert Richland, Washington Site Area Emergency Dockets: 07001257 License No: SNM 1227 General Emergency X Not Applicable

Subject:

UO2 EXCEEDED MOISTl8'<E LIMIT On September 17,1997, Siemens Nuclear Power Corporation (SNPC) reported the discovery of damp uranium dioxide material (UO2) in a transfer line in the dry conversion pilot facility UO2 sample analyses of the pyrohydrolysis vessel (source of the UO2 material) revealed the moisture content of materialin the vessel slightly exceedeo the one weight percent limit. The licensee's report was made pursuant to NRC Bulletin 91-01 (4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />).-

Late on September 16,1997, due to operational dif ficulties, the licensee had decided to clean out _UO2 material from a 3 inch transfer line. The transfer line is a favorable geornetry connector _ between the pyrohydroisis vessel (converts UF6 to UO2) to the calciner. Upon disassembly of the line, operators discovered damp UO2 material. Sample analysis of the 29 kg of UO2 material remaining in the vessel were found to exceed the one weight percent limit.

-The highest sample analysis of material known to come exclusively from the vessel was 1.09 weight percent._ The highest sample obtained was 1.6 weight percent, but this sample was of a mixture of material from the vessel and the transfer line, which was known to have a higher moisture content. The UO2 has subsequently been removed from the system.

-The vessel converts UF6 to UO2 by reacting the UF6 with steam and other gases at elevated temperatures. This vessel has two significantly different sections. The lower section of the vessel contains the majority of the material during processing and is favorable geometry while the upper section contains very little material and is not f avorable geometry. Controlling the

_ amount of moderator in the vessel and ensuring an adequate temperature before steam is supplied to the vessel are the key criticality safety controls for this process. The process is supposed to limit the materialin this vessel to less than one weight porcent moisture.

The system was initially shut down on September 16,1997, to investigate the problem and remains shut down pending SNPC investigation and completion of corrective actions. SNPC personnel have reviewed the criticality safety analysis for the process system in question and are evaluating whether or not the moderator entered the pyrohydrolysis vessel from an evaluated pathway.

9709190023 970918 I "

PDR I&E PNO-IV-97-053 PDR 100010 i

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PNO IV 97 053 2-An NRC inspector is on tite for a routine inspection and is now reviewing the occurrence.

Region IV has briefed NMSS.

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-The state of Washington will be informed.

Region IV received notification of this occurrence by telephone from the on site inspector at 2:30 p.m. (PDT) on September 17,1997.

This information has been discussed with the licensee ant ". current as of 0830 PDT, Sep*. ember 18,1997.

Contact:

Frank Wenslawski Ross Scarano (510)975-0219 (817)860 8100 i