05000219/FIN-2013003-03
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Finding | |
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| Title | Difference In Interpretation Of Guidance Contained NEI 99-02 Submitted Into TheFrequently Asked Question Process |
| Description | Exelon planned a downpower to 70% power for end of cycle control rod conditioning starting at 2300 on September 28, 2012 with a target completion time of 0700, September 29, 2012. At 1855 on September 28, 2012, operators lowered power to 85% in order to remove the A-north condenser from service to allow maintenance workers to repair a pre-existing patch on the A-north condenser circulating water discharge piping which had exhibited an increased leakage rate earlier in the day. At 2305 on September 28, 2012, operators lowered power to 70% to perform the planned control rod conditioning evolution. At 0033, on September 29, 2012, operators commenced raising power to full power following completion of the control rod conditioning. At 0115 on September 29, 2012, Exelon decided to stop the power ascension and hold power at 80% to assess repair options for the A-north circulating water piping. At 0302 on September 29, 2012, operators lowered power to 70% to set conditions for maintenance workers to perform repairs. Repairs to the A-north circulating water piping were completed by station personnel at 1539 and operators returned the plant to full power at 1843 on September 29, 2012. NEI 99-02 Regulatory Assessment Performance Indicator Guideline, Revision 6 defines an unplanned power change as follows: Unplanned changes in reactor power are changes in reactor power that are initiated less than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> following the discovery of an off-normal condition, and that result in, or require a change in power level of greater than 20% of full power to resolve. Unplanned changes in reactor power also include uncontrolled excursions of greater than 20% of full power that occur in response to changes in reactor or plant conditions and are not an expected part of a planned evolution or test. The inspectors determined that this downpower should count towards the unplanned power changes performance indicator for the following reasons: Power was initially lowered in response to an off-normal condition, an increase in leakage from a patch on the A-north condenser circulating water discharge piping. Power was lowered 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> earlier than the planned control rod conditioning starting time and repairs required an additional 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to complete beyond the planned completion time for the control rod conditioning. Power was lowered to 70% to resolve the off-normal condition. Power ascension following the control rod conditioning was interrupted and a second downpower evolution was conducted to perform the repairs on the circulating water piping. Exelon determined that this downpower should not count towards the unplanned power changes performance indicator for the following reasons: The initial unplanned downpower was 15% and would not be subject to the performance indicator criteria of 20%. The downpower to 70% for the control rod conditioning was planned and was extended to conduct repairs to the A-north circulating water piping. The inspectors and Exelon could not resolve the differences in the interpretation of the NEI guidance and the issue will be submitted into the frequently asked question process for resolution. |
| Site: | Oyster Creek |
|---|---|
| Report | IR 05000219/2013003 Section 4OA1 |
| Date counted | Jun 30, 2013 (2013Q2) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71151 |
| Inspectors (proximate) | A Patel B Bollinger E Burket J Furia J Kulp K Mangan P Kaufman S Pindale T Hediganb Dionneb Bollinger S Pindale G Hunegs W Schmidt J Kulp P Presby A Patel C Newport S Ibarrola |
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Finding - Oyster Creek - IR 05000219/2013003 | ||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Oyster Creek) @ 2013Q2
Self-Identified List (Oyster Creek)
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