05000285/FIN-2012009-03
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Finding | |
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| Title | Assess Corrective Actions and Determine Structural Effect of Water Intrusion and Boric Acid on Interior Containment Walls |
| Description | During containment walk downs in the steam generator bays, the inspectors verified the presence of a significant amount of boric acid on the bioshield walls in both steam generator bays outside of the reactor compartment near both the hot and cold legs. Because of the presence of insulation, the inspectors could not identify the condition of the piping and structures inside the bioshield. The licensee indicated the boric acid came from the refueling cavity liner when flooded up during refueling outages. The licensee had initiated a task team to resolve this condition and documented various deficiencies in roll-up Condition Report 2012-00116. The licensee initiated Condition Report 2011-05763 that documented the presence of an eight foot long horizontal crack above the reactor cavity liner leak-off line in the reactor cavity wall. The inspectors noted that the licensee had identified a similar deficiency in 2003, as documented in Condition Report 2003-04261. The licensee concluded the leakage through the crack did not affect the wall structurally based on no evidence of degraded reinforcing steel, the amount of reinforcement, and the thickness of the wall. The inspectors confirmed that Part 9900, Operability Determinations and Functionality Assessments for Resolution of Degraded or Nonconforming Conditions Adverse to Quality or Safety, Section C.13 specified that degraded structures remain operable so long as the degradation does not result in exceeding any acceptance limits specified in the codes and standards specified in the design basis. The licensee also compared the trends of reactor cavity liner leak-off line flow rates to previous outages. The review of trends confirmed that leakage remained constant and low for the last three outages. The inspectors verified no brown discoloration that would indicate wastage of reinforcing steel from the crack. The inspectors questioned the origin of a wetted brown stain on the reactor cavity wall below the insulation around the Steam Generator B hot leg. Consequently, the licensee initiated Condition Report 2012-05067 to determine the cause and take corrective actions. The licensee had previously identified this condition in February 2012, as documented in Condition Report 2012-01339, but had not taken any corrective actions. The inspectors will review the licensee actions to identify and address reactor cavity liner leakage and its impact on the containment structures during a future inspection. This is considered an unresolved item. |
| Site: | Fort Calhoun  |
|---|---|
| Report | IR 05000285/2012009 Section 4OA5 |
| Date counted | Jun 30, 2012 (2012Q2) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | |
| Inspectors (proximate) | G Meyer G Miller G Pick J Melfi J Rivera Ortiz S Makorc Speerg Miller G Pick S Makor |
| INPO aspect | |
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Finding - Fort Calhoun - IR 05000285/2012009 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Fort Calhoun) @ 2012Q2
Self-Identified List (Fort Calhoun)
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