ENS 50282
ENS Event | |
|---|---|
14:42 Jul 15, 2014 | |
| Title | Unanalyzed Condition - Low Containment Spray Flow Rate |
| Event Description | At 0942 [CDT] on 7/15/2014, the 2A Containment Spray chemical additive flow was found out of tolerance low during surveillance testing. This resulted in an unanalyzed condition in that insufficient chemical additive flow might have resulted in lower than assumed containment spray pH values during past periods.
Based on the above, this is being reported in accordance with 10CFR50.72(b)(3)(ii)(B). Actions are in progress to restore the 2A Containment Spray chemical additive flow to within tolerance. The 2B Containment Spray system is operable per Technical Specification 3.6.6 and is capable of providing required chemical additive flow. The required flow is 18 to 67 gallons per minute (gpm), however, the measured flow was 17.96 gpm. The licensee has notified the NRC Resident Inspector.
The purpose of this report is to retract ENS report #50282 (July 15, 2014). This ENS report was made for the 2A Containment Spray chemical additive flow which was found out of tolerance low during surveillance testing. At the time of reporting, it was concluded that this was an unanalyzed condition in that insufficient chemical additive flow may have resulted in lower than assumed containment spray pH values during past periods. This was reported in accordance with 10CFR50.72(b)(3)(11)(B) as an unanalyzed condition that significantly degrades plant safety. On Wednesday, July 29, 2014, Braidwood Generating Station concluded that the prior ENS notification could be retracted based on the completion of Engineering Change 398884, 'Evaluation Of 2A CS NaOH Spray Additive Test Results And Discussion of IRs 1682209 and 1683413.' The Engineering Change concluded that the approval of the alternate source term (AST) license amendment resulted in the elimination of a minimum containment spray (CS) spray pH value. The current containment release analysis does not credit the addition of sodium hydroxide (NaOH) to CS spray for fission product removal from the containment atmosphere. The long-term retention of captured fission products in the sump water assumes the sump water pH is greater than 7. This is established by the transfer of the containment spray additive tank (CSAT) contents to the sump during CS system operation. To transfer the maximum CSAT inventory to the sump within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, a minimum NaOH eductor flow of approximately 10 gpm is required. The minimum NaOH injection flow for the 2A CS eductor system exceeded 10 gpm so the eductor injection flows meet the criteria to transfer CSAT inventory to the containment recirculation sump within the expected minimum CS system operating time. The out of tolerance flow values recorded at the time of the initial ENS notification are acceptable. The licensee has notified the NRC Resident Inspector. Notified the R3DO (Lara). |
| Where | |
|---|---|
Braidwood  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+3.25 h0.135 days <br />0.0193 weeks <br />0.00445 months <br />) | |
| Opened: | Joe Conquest 17:57 Jul 15, 2014 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Aug 1, 2014 |
| 50282 - NRC Website | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 519592016-05-25T19:15:00025 May 2016 19:15:00
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