ML20117A634
| ML20117A634 | |
| Person / Time | |
|---|---|
| Site: | Pennsylvania State University |
| Issue date: | 11/25/1992 |
| From: | Voth M PENNSYLVANIA STATE UNIV., UNIVERSITY PARK, PA |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9211300242 | |
| Download: ML20117A634 (1) | |
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PENNSTATE Oi;iLo College of Igineering brea/eale Nuclear Reutor Hiiildtiig ksbnon Narnte and 1.ngmeenny Center The Pennsylvania Sute 1%eruiy Unneruty l' art,l% If402 2301 November 25,1992 US Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Re:
Closure of October 14 Report on inadvedent Reactivity Addition Penn State Breazeale Reactor License Number R-2, Docket Number 50 05 On October 5,1992, an incident occurred at the above facility. In summary, an operator, when changing a control system parameter with all rods fuly inserted, erred and caused an inadsertent partial wiUidrawal of one rod. A full description and analysis was given in the October 14,1992 report to the NRC.
Continued study of the event has confirmed our initial conclusions that the root causes were: (1) t 3erator error and (2) inadequate procedural controls on software tuning cha1ges.
Procedural controls have been implemented to allow software tuning changes only when the change is detailed and controlled by a standard facility procedure, an approved experiment authorlation, or by implementation of the facility change procedure. This ensures that each tuning change is described, analyzed, and approved by the appropriate oversight individual, committee, or agency prior to implementation. In addition, no tuning changes are allowed to occur unless (1) the core is unloaded such that it is subcritical with all rods withdrawn or (2) all control rods are fully inserted and physically or electrically rendered incapable of belng withdrawn from the core.
Sincerely, i
Marcus H. Voth l
Associate Professor, Nuclear Engineering l
Director, Radiation Science & Engineering Center l
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9211300242 921125 PDR ADOcK 05000005 l
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