05000275/FIN-2011004-08
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Finding | |
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| Title | Licensee-Identified Violation |
| Description | Title 10 CFR 50.72, Immediate Notification Requirements for Operating Nuclear Power Reactors, required the licensee to notify the NRC Operations Center within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after discovery of a non-emergency event as described in Paragraph (b)(3)(v). Paragraph (b)(3)(v) included any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. Contrary to the above, the licensee failed to notify the NRC Operations Center within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after discovery of a condition that could have prevented the fulfillment of the safety function of structures and systems that are needed to mitigate the consequences of an accident. Specifically, on August 29, 2011 plant operators identified that the integrity of the control room habitability envelope had been lost. The integrity of the envelope was lost earlier in the day after maintenance personnel erroneously removed a blank flange supporting maintenance on a ventilation system inlet isolation damper. The loss of envelope integrity could have prevented the system from meeting the safety function to limit radiation exposure to control room operators to less than 5 rem (dose equivalent) following an accident. The violation was screened as very low safety significance (Green) because the finding was not a design or qualification deficiency confirmed not to result in loss of operability or functionality, did not represent a loss of system safety function, and did not screen as potentially risk significant due to a seismic, flooding, or severe weather initiating event. The licensee entered the condition into the corrective action program as Notification 50424433 and made the required notification on August 30, 2011. |
| Site: | Diablo Canyon  |
|---|---|
| Report | IR 05000275/2011004 Section 4OA7 |
| Date counted | Sep 30, 2011 (2011Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | Licensee-identified |
| Inspection Procedure: | |
| Inspectors (proximate) | G Guerra M Peck G Miller C Osterholtz E Ruesch D Reinert L Micewski |
| INPO aspect | |
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Finding - Diablo Canyon - IR 05000275/2011004 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Diablo Canyon) @ 2011Q3
Self-Identified List (Diablo Canyon)
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