ML20045D882
| ML20045D882 | |
| Person / Time | |
|---|---|
| Site: | Framatome ANP Richland |
| Issue date: | 06/17/1993 |
| From: | Maas L SIEMENS POWER CORP. (FORMERLY SIEMENS NUCLEAR POWER |
| To: | Gould C NRC |
| References | |
| IEB-91-001, IEB-91-1, NUDOCS 9306300167 | |
| Download: ML20045D882 (2) | |
Text
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"SIEMENS' June 17,1993 To:
U.S. Nuclear Regulatory Commission Operations Center Attn: C. Gould.
From: L. J. Maas A
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MGR, Regu atory Compliance Siemens Power Corporation Richland Wa.
Ucense SNM-1227
Subject:
Bulletin 91-01 Reportable Criticality Safety Violation-Un-authorized Equipment '
Modification.
Backoround i
Siemens Power Corporation (SPC) has three UO Pellet grinder lines. The grinders on each -
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2 of the three lines are used to grind pellets to the desired diameter; Water is supplied to the grinder wheels to cool the grinder wheel and to wash UO Particles from the pellet and 2
grinder wheel. The grinder line water systems are closed looped systems. The grinder water -
loop includes a heat exchanger, two filters, a centrifuge, and a centrifuge reservoir.
One of the criticality safety requkements for the centrifuge reservoir is for the maximum solution depth to be limited to 8.0 inches. The approved design for this system included an -
overflow at 8.0 inches to assure this limit is met. The overflo'w line consisted of a pipe and an eli to direct any overflow toward the floor.
Description As part of an ongoing program to update the criticality safety analyses at SPC, SPC personnel identified that an eli on the end of each of the centrifuge reservoir overflow lines had been turned upward. The depth of solution before overflow in this configuration is about 10 inches.
The system was immediately returned to the approved configuration and design changes were initiated to modify the reservoir to include more positive methods of limiting the possible solution depth.
900v"O i y' Siemens Power Corporation
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Nuclear Division - Engineering and Manufacturing Facility
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2101 Horn Rapids Road, PO Box 130 JiichlaM, WA 99352-0130 Tel: (509) 375-8100 Fax: (509) 375-8402
.9306300167 930617' PDR. ADOCK-07001257 PDR
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4 Docume'nt Control Desk Page 2 June 17,1993 A telephone report to NRC headquarters was made in accordance with NRC bulletin 91-01.
This report was made because of a degradation in a controlled parameter. However, the actual solution depth had not been exceeded, the reservoir is equipped with functional level-indication, and operators are instructed to limit the solution depth to between 5 and 6 inches.
Furthermore the filtering system design and controls in place on the centrifuge operation make it very unlikely that even a safe mass (45% of minimum critical mass) of uranium would be present in the centrifuge reservoir. For these reasons a criticality accident in this system -
was not possible. K-eff at the 10 inch full configuration assuming optimum moderation and reflection was calculated to be 0.9658 +.0044 1
Cause and Lonci Term Corrective Actions The cause and long term corrective actions are under investigation and will be included in a written follow up report of this criticality safety incident.
cc:
E. G. Adensaml NRC HQ B. Fauikenberry, NRC Region V t
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