ML20059E621
| ML20059E621 | |
| Person / Time | |
|---|---|
| Site: | Framatome ANP Richland |
| Issue date: | 12/29/1993 |
| From: | Maas L SIEMENS CORP. |
| To: | Karsch R NRC |
| References | |
| IEB-91-001, IEB-91-1, NUDOCS 9401120069 | |
| Download: ML20059E621 (2) | |
Text
. _ - ~
g SIEMENS December 29,1993 To:
U.S. Nuclear Regulatory Commission l
Operations Center Attn:
R. Kar ch l
a From: L J. Maas Ov t.
gw l
Mgr, Regul tory Compliance Siemens Power Corporation - Nuclear Division Richland, WA Ucense SNM-1227
Subject:
Bulletin 91-01 Reportable Criticality Safety Violation - Criticality Safety Specification for Storage of BWR Fuel Assemblies inconsistent with Criticality.
Safety Analysis.
Introduction Siemens Power Corporation - Nuclear Division (SPC-ND) operates a low-enriched uranium l
fuel fabrication facility in Richland, WA. under NRC Ucense No. SNM 1227 (NRC Docket No.
l 70-1257). The subject criticality safety violation described below is being reported to the US NRC under NRC Bulletin 91-01 by L. J. Maas, Manager, Regulatory Compliance (phone no.
509-375-8537).
Description of Violation On 12/28/93 as part of an ongoing Criticality Safety Update Program, SPC-ND criticality safety personnel discovered that BWR fuel assemblies had been stored in locations not specifically analyzed in the applicable CSA.
Backaround A reanalysis was being performed on the vertical fuel assembly storage rack located in the fuel storage area of the UO Building. As a result of th:s review, SPC criticality safety 2
l personnel determined that BWR fuel assemblies had been incorrectly stored on some occasions in the past. At approximately 1430 hours0.0166 days <br />0.397 hours <br />0.00236 weeks <br />5.44115e-4 months <br /> on 12/28/93, SPC personnel further determined that the arrangement of BWR fuel assemblies currently being stored was not specifically covered by the existing criticality safety analysis. The 14 fuel assemblies involved were immediately relocated to alternate storage locations. All other criticality safety limits and controls for the storage rack were verified to be met.
9401120069 931229 F
PDR ADOCK 07001257
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,fg/k Siemens Power Cofp6rstiNri'2 Nuclear Dwoon - Engineenng ard Manufactunng Facihty 0
2101 Horn Rapds Road PO Box 130 Richland. WA 993520130 Te! (509) 375 8100 Far (509) 375 8402
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December 29,1993 The vertical fuel assembly storage area for BWR fuel assembly storage has storage locations for a 9 X 20 array of BWR fuel assemblies. Four of these rows are only used occasionally.
The 14 assemblies in question were stored in two of these infrequently used rows. The criticality safety specification did not clearly specify the required center-to-center spacing for these infrequently used rows (as defined in the applicable criticality safety analysis.) The center-to-center spacing between these two rows was measured at 13 inches.
l The existing criticality safety analysis shows the peak k-eff for the allowed configuration at l
optimum moderation to be about 0.82. The analysis also shows that an infinite array of BWR assemblies enriched to 4.0 wt.% U-235 placed on 12 inch centers has a k-eff of less than 0.85 at full flooding. However, the analysN; does not give k-eff for BWR fuel assemblies enriched to 4.0 wt.% on 12 inch centers at optimum moderation.
Evaluation and Followup Based on the other criticality safety controls remaining in place and the conservatism incorporated into the criticality safety analysis, conditions required for a criticality accident were not approached. The potential for adverse impacts to on-site workers or the general public was insignificant and no additional notifications were determined to be necessary.
The necessary long term corrective actions are currently being evaluated by SPC personnel.
Any needed changes will be made before the storage locations in question will be used in the future. Results of the evaluation will be documented in a 30-day followup report.
cc:
B. H. Faulkenberry, NRC Region V