05000458/FIN-2018301-01
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Finding | |
|---|---|
| Title | Inadequate Procedure for Shutdown Operations Protection Plan |
| Description | The team reviewed a self-revealed Green non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, for the failure to provide accurate qualitative procedural guidance to determine Shutdown Cooling Safety Function color state in Modes 4 and 5, using OSP-0037, Rev 36, Shutdown Operations Protection Plan, Attachment 1, Shutdown Cooling Function Color States. Specifically, OSP-0037 Rev 36 defines the term Flooded Up as, Flooded Up condition requires greater than 23 ft in the Reactor Cavity and the Cavity Gate open. OSP-0037 Rev 36, Attachment 1 contains a table with 6 columns that list combinations of decay heat loads (high, medium, and low), and reactor cavity water inventory, which are used to determine Shutdown Cooling risk. Only one of the six columns uses the correctly-defined term, Flooded Up, for reactor cavity water inventory. Two of the six columns state Flooded, and three of the columns state Not FL, neither of which are defined terms in OSP-0037. This creates the potential for an operator to misinterpret the meaning of the column, and select a color code for Shutdown Cooling that represents a lower risk than is actually present. This potential was confirmed by erroneous applicant performance on the July 2018 NRC initial license exam. As an interim corrective action, the station issued a night order clarifying the typographical error, and initiated action to revise the procedure. This issue was entered into the licensees corrective action program as Condition Report CR-RBS-2018-04414
The failure to provide accurate qualitative procedural guidance to determine Shutdown Cooling Function Color State is a performance deficiency. The inspectors determined the performance deficiency was more than minor because it adversely affected the Procedure Quality attribute of the Mitigating Systems cornerstone, the objective of which is to ensure the availability, reliability, and capability of systems needed to respond to initiating events to prevent undesired consequences. Specifically, the procedure errors could cause a crew to underestimate Shutdown Cooling risk, with an adverse effect on conservative implementation of defense in depth in the planning, scheduling, and implementation of outage activities. The inspectors assessed the significance of the finding using Inspection Manual Chapter 0609, Appendix G, Shutdown Operation Significance Determination Process, dated May 9, 2014. The team determined that the finding was of very low safety significance (Green) because the finding: (1) was not a deficiency affecting the design and qualification of a mitigating structure, system, or component, and did not result in a loss of operability or functionality; (2) did not represent a loss of system and/or function; (3) did not represent an actual loss of safety function of any train or safety system for longer than its technical specification allowed outage time, or two separate safety systems out-of-service for longer than their technical specification allowed outage time; (4) did not represent an actual loss of function of one or more non-technical specification trains of equipment designated as high safety-significance in accordance with the licensees maintenance rule program, with cavity either flooded or not flooded; (5) did not degrade a functional auto-isolation of RHR on low reactor vessel level; (6) did not screen as potentially risk significant due to an external event; (7) did not involve Fire Brigade training and qualification requirements, or brigade staffing; (8) did not involve the response time of the Fire Brigade to a fire; and (9) did not involve fire extinguishers, fire hoses, or fire hose stations. No Cross-Cutting Aspect is assigned, because the procedural errors were introduced in Revision 19, issued September 16, 2009, and are therefore not indicative of current licensee performance. |
| Site: | River Bend  |
|---|---|
| Report | IR 05000458/2018301 Section 4OA5 |
| Date counted | Sep 30, 2018 (2018Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | Self-revealing |
| Inspection Procedure: | |
| Inspectors (proximate) | T Farina J Kirkland C Osterholtz M Hayes N Hernandez V Gaddy |
| Violation of: | 10 CFR 50 Appendix B Criterion V |
| INPO aspect | |
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Finding - River Bend - IR 05000458/2018301 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (River Bend) @ 2018Q3
Self-Identified List (River Bend)
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