ENS Event | |
|---|---|
04:00 Feb 18, 2021 | |
| Title | Part 21 Report |
| Event Description | The following is a summary of a report received from the vendor via email:
The vendor notified the NRC that the hydraulic loss coefficient used to calculate the pressure loss and flow rate into the Side Entry Orifice (SEO) at the fuel bundle entrance in BWR/6 plants may have been underpredicted. The SEO loss coefficient was underpredicted for some fuel bundle locations, which could result in an overprediction of MCPR margin in core monitoring applications. The overprediction was a result of not originally including in the assessment flow area restrictions associated with instrument support structures in the cross beams (structural supports underneath the core plate) in BWR/6 plant designs. BWR/2-5 plants built by GE have a different core support structure that is more open so that multiple SEO losses are not applied to evaluations for those plants. However, there are currently no US ABWR plants in operation that would potentially be affected by this evaluation. The potential error in the core monitoring system does not affect the NRC certified design of the ABWR or the GEH ABWR design certification renewal application currently under review. The unique core support structure design of the BWR6 and ABWR is not shared by earlier BWR plants or the ESBWR. Potentially Affected Plants: Grand Gulf, River Bend, Clinton, Perry Point of Contact: Michelle Catts Safety Evaluation Program Manager 3901 Castle Hayne Road, Wilmington, NC 28401 |
| Where | |
|---|---|
| Ge Hitachi Nuclear Energy Wilmington, North Carolina (NRC Region 1) | |
| Organization: | Ge Hitachi Nuclear Energy |
| Reporting | |
| 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
| Time - Person (Reporting Time:+2867.43 h119.476 days <br />17.068 weeks <br />3.928 months <br />) | |
| Opened: | Jim Harrison 14:26 Jun 17, 2021 |
| NRC Officer: | Jeffrey Whited |
| Last Updated: | Jun 17, 2021 |
| 55314 - NRC Website | |
Ge Hitachi Nuclear Energy with 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
WEEKMONTHYEARENS 553142021-02-18T04:00:00018 February 2021 04:00:00
[Table view]10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 Report ENS 547562020-04-28T04:00:00028 April 2020 04:00:00 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 Report - Non-Conservative Bwr/6 Side Entry Orifice Loss Coefficients ENS 496102013-10-09T05:00:0009 October 2013 05:00:00 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 - Failure of Relay Logic Card Modules in 2 Out of 4 Voters for Power Range Monitors ENS 487352013-02-08T05:00:0008 February 2013 05:00:00 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 - Completed Evaluation for Potential Error in Main Steam Line High Flow Calculational Methodology 2021-02-18T04:00:00 | |