05000275/FIN-2009002-02
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Finding | |
|---|---|
| Title | Inadequate Procedure |
| Description | The inspectors reviewed a self-revealing noncited violation of Technical Specification 5.4.1 for failure to develop a procedure for removing the reactor head from the reactor pressure vessel and the subsequent filling of the reactor coolant system in a manner that would minimize the potential for airborne contamination. Specifically, on March 5, 2009, while lifting the reactor vessel head in preparation for reloading the reactor core, the licensee experienced airborne radioactivity as high as 4.8 derived air concentrations due to the delay in flooding the reactor refuel cavity. The delay allowed the radioactive contamination on the reactor upper internal structure to dry and subsequent air flow around the upper internal structure caused the contamination to become airborne. The licensee evacuated unnecessary personnel from the containment, initiated containment purge to reduce airborne contamination, and obtained air samples until airborne contamination levels were reduced to normal levels (less than 0.2 derived air concentrations). The licensee entered this item into the corrective actions program as Notification 50209442 and is conducting an apparent cause evaluation of the event. The failure to develop and implement procedures for removing the reactor head and filling the reactor coolant system in a manner that minimized the potential for airborne radioactivity is a performance deficiency. The finding is greater than minor because it is associated with the Occupational Radiation Safety Cornerstone attribute of the program and process and affected the cornerstone objective of exposure/contamination control in that failure to develop and implement adequate procedures for removing the reactor vessel head and fill the reactor coolant system resulted in workers unplanned, unintended dose. Using the Occupational Radiation Safety Significance Determination Process, the inspectors determined this finding had very low safety significance because the finding involved as low as is reasonably achievable planning and work controls, and the licensees 3-year rolling average collective dose is less than 135 person-rem per unit. Because the AMS-4 on the refuel floor in containment alarmed at an airborne concentration of greater than 0.5 derived air concentrations, the finding is self-revealing. Additionally, the finding had a crosscutting aspect in the area of human performance, work control component, because the licensee failed to plan and coordinate work activities by incorporating job site conditions which may impact radiological safety H.3(a). |
| Site: | Diablo Canyon  |
|---|---|
| Report | IR 05000275/2009002 Section 2OS1 |
| Date counted | Mar 31, 2009 (2009Q1) |
| Type: | NCV: Green |
| cornerstone | Or Safety |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71121.01 |
| Inspectors (proximate) | M Brown M Peck B Henderson D Stearns G George V Gaddy C Alldredge M Vasquez |
| CCA | H.5, Work Management |
| INPO aspect | WP.1 |
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Finding - Diablo Canyon - IR 05000275/2009002 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Diablo Canyon) @ 2009Q1
Self-Identified List (Diablo Canyon)
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