ENS 50189
ENS Event | |
|---|---|
19:34 Jun 11, 2014 | |
| Title | One Containment Spray Train Chemical Additive Flow Out of Specifications |
| Event Description | At 1434 [CDT] on 06/11/14, the 1A 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. The impact of the unanalyzed condition has not been fully evaluated. Based on the above, this is being reported in accordance with 10CFR50.72(b)(3)(ii)(B). Engineering analyses are in progress to evaluate the past condition. Actions are in progress to restore the 1A Containment Spray chemical additive flow to within tolerance. The 1B Containment Spray system is operable per Tech Spec 3.6.6 and is capable of providing required chemical additive flow.
The required flow is 30 to 63 gpm. Measured flow was 27 gpm. The last measurement was six years ago. The licensee notified the NRC Resident Inspector.
The purpose of this report is to retract EN report #50189 (June 11, 2014). This EN report was made for the 1A 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)(ii)(B) as an unanalyzed condition that significantly degrades plant safety. At approximately 1700 CDT on Thursday, June 12, 2014, Braidwood Generating Station concluded that the prior EN notification could be retracted based on the completion of Engineering Change 398472, 'Evaluation of As-Found Results for 1A Containment Spray NaOH Additive Flow.' 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 1A CS eductor system (27.0 ' as-found' and 27.7 'as-left' gpm) 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 notification are acceptable. The licensee has notified the NRC Resident Inspector. Notified R3DO (Daley). |
| Where | |
|---|---|
Braidwood  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+3.13 h0.13 days <br />0.0186 weeks <br />0.00429 months <br />) | |
| Opened: | Joey Trudeau 22:42 Jun 11, 2014 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Jun 13, 2014 |
| 50189 - NRC Website | |
Unit 1 | |
|---|---|
| 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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