ML18177A208
| ML18177A208 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 06/27/2018 |
| From: | DTE Energy |
| To: | Division of Operating Reactor Licensing |
| Green K, 415-1627 | |
| References | |
| Download: ML18177A208 (18) | |
Text
Fermi Unit 2 License Amendment Pre-submittal Meeting Neutron Absorbing Inserts June 27, 2018 1
Agenda
- Objectives Kevin Lynn (DTE)
- Background Kevin Lynn (DTE)
- NETCO-SNAP-IN Rack Inserts Matt Harris (Curtiss-Wright)
- Summary / Questions / Feedback Kevin Lynn (DTE)
- Criticality Analysis (Closed Portion) Chris Kmiec (GNF)
Fermi 2 License Amendment Pre-Submittal Meeting 2
Objectives
- Provide the NRC with an overview of the proposed license amendment request (LAR):
- Scope and content
- Methodology
- Submittal schedule
- Obtain NRC feedback
- Content
- Approval schedule
- Lessons learned Fermi 2 License Amendment Pre-Submittal Meeting 3
Background
- Fermi 2 spent fuel pool (SFP) contains two types of storage racks:
Boral (Holtec) and Boraflex (Joseph Oat)
- During license renewal, a license condition was imposed that:
DTE Electric Company shall fully implement the Boraflex rack replacement approved in Amendment No. 141 before the PEO (i.e., March 20, 2025), so that the Boraflex material in the spent fuel pool will not be required to perform a neutron absorption function. DTE Electric Company shall submit a letter to the NRC, within 60 days following completion of the removal of the Boraflex material and installation of the Boral material, as described in Amendment No. 141, confirming the removal of the Boraflex material and discontinued reliance on its neutron absorption function.
- As an alternative to implementing the previously approved amendment to replace the Boraflex racks with Boral racks, DTE is proposing to place neutron absorbing inserts (NETCO type) into the Boraflex racks Fermi 2 License Amendment Pre-Submittal Meeting 4
Spent Fuel Pool Layout
- Current SFP layout based on UFSAR Figure 9.1-3 (sheet 3) o Boraflex storage racks shown in white o Boral storage racks shown in yellow Fermi 2 License Amendment Pre-Submittal Meeting 5
License Amendment Request Overview
- DTE is requesting a license amendment to eliminate the operating license condition regarding Boraflex
- The criticality analysis will take no credit for neutron absorption by Boraflex but will credit NETCO type neutron absorbing inserts
- Criticality analysis follows guidance in NEI 12-16, Revision 2, Draft B
- No interim criticality analysis will be included
- Criticality analysis to be discussed further in closed (proprietary) session
- LAR will be similar to those previously reviewed and approved by NRC such as Quad Cities, Peach Bottom, and LaSalle Fermi 2 License Amendment Pre-Submittal Meeting 6
License Amendment Request Overview
- Additional analyses for the inserts will address:
- Structural and seismic considerations
- Thermal-hydraulic evaluations
- LAR will also include enclosures for:
- NETCO reports
- Criticality analysis report by GNF (proprietary & non-proprietary versions)
- Affidavit (for withholding proprietary version)
Fermi 2 License Amendment Pre-Submittal Meeting 7
License Amendment Request Overview
- In addition to removal of the license condition, other proposed changes to the Technical Specifications (TS):
- TS 4.3.1.a will be revised to slightly reduce the maximum kinfinity (peak in-core kinfinity limit)
- TS 4.3.1.c will be modified to describe the NETCO inserts as the neutron absorbing material rather than Boraflex
- TS 5.5.13 will be eliminated since monitoring the neutron absorbing properties of Boraflex will not be necessary Fermi 2 License Amendment Pre-Submittal Meeting 8
License Amendment Request Overview
- License Renewal added Neutron-Absorbing Material Monitoring Program to Fermi 2 UFSAR Section B.1.27
- UFSAR Section B.1.3 states that all neutron-absorbing material to be credited during the period of extended operation will be managed by the program described in UFSAR Section B.1.27
- The program currently only applies to Boral, but would apply to the new inserts as soon as they are credited
- The program includes periodic inspection, testing, and monitoring
- Additional enhancements to the program, such as inspection frequency and coupon trending, are required to be implemented six months prior to the period of extended operation (September 20, 2024) as part of License Renewal commitments Fermi 2 License Amendment Pre-Submittal Meeting 9
License Amendment Request Overview
- Target date for submittal is late 2018
- Installation of inserts may be performed under 10 CFR 50.59, but no credit for neutron absorption will be taken prior to LAR approval and implementation
- Installation schedule is based around refueling outage schedules, but is targeted to begin in the fall of 2020
- Completion of installation and implementation of LAR, when approved, is targeted for summer of 2021
- This tentative schedule allows for elimination of the Boraflex license condition several years before the required deadline of March 20, 2025 Fermi 2 License Amendment Pre-Submittal Meeting 10
Nuclear Division NETCO SNAP-IN Rack Inserts:
Neutron Absorber Panels for Fermi Boraflex Spent Fuel Racks 11 l June 27, 2018 l © 2014 Curtiss-Wright
What are NETCO-SNAP-IN Inserts?
Designed to Retrofit Operating Spent Fuel Pool Storage Racks.
- Replaces or supplements existing neutron absorber
- Friction fit keeps it in place without need for separate mechanical retention Allows Continued Use of Current Fuel Storage Rack
- Avoid cost of rack replacement
- Avoid personnel dose from rack replacement
- Avoid cost of old rack disposal Minimizes the impact to fuel handling and storage operations
- Minimum Profile in Cell Made from Aluminum-B4C Composite Once Installed, NETCO-SNAP-IN Inserts are an Integral Part of the Rack Module 12 l June 27, 2018 l © Curtiss-Wright
Application When Placed in Each Storage Location, the NETCO-SNAP-IN Inserts Can Completely Replace the Neutron Poison in the Existing Racks Already Installed in Multiple BWR Rack Types
- Joseph Oat*
- US Tool and Die Once Installed, Fuel Can Be Moved In and Out of the Storage Locations as Usual Consideration of Other Rack Regions Will Dictate Insert Orientation to Address Interfaces 13 l June 27, 2018 l © Curtiss-Wright
Install Base - BWR Racks LASALLE QUAD CITIES* PEACH BOTTOM LAR Approval Was Granted 1/28/11 LAR Approval Was Granted LAR Approval Was Granted 5/21/2013 4073 Inserts Installed In Less Than 1 12/31/2014 Year Over 7000 Inserts Installed on Installed Inserts In Advance Of LAR schedule.
Installation Rate Averaged About 20 Approval Inserts Per Day Installation completed in 2016.
Installation Complete In 2014 No Longer Credits Boraflex Install rate approached 50-60/day; Lasalle NETCO-SNAP-IN Insert No Longer Credits Boraflex Less rapid than J. Oat racks due to Installation Won 2013 TIP Award formed and resultant cells.
Peak Installation Rate Of About
- The inserts are currently the 100/Day RTA- W1100N.19B most feasible and economic solution to Boraflex degradation RTA- W1100N.17B available.
RTA -W1100N.16B 4073 Inserts 7554 Inserts 7638 Inserts 14 l June 27, 2018 l © Curtiss-Wright
NETCO-SNAP-IN Insert Design and Testing Three Major Phases Dimensional Testing Prototype
- Un-Borated Absorber Fit Development Test
- Site Specific Design
- Variance Analysis Drawings
- Retention Force Testing
- Rack Mock-Ups
- Clean Environment Testing
- Functional Tests prior to actual pool testing
- Clean Environment Testing prior to actual pool testing Requirements Analysis
- Criticality Hold Down Requirements
- Fuel Fit Requirements
- Rack Dimensional Variance Analysis 15 l June 27, 2018 l © Curtiss-Wright
Robust Neutron Absorber Qualification Produced to Significantly Exceed Minimum Certified Value Material Performance Testing
- Multiple Surveillance Test Results Show Consistency with Accelerated Test Predictions
- Recent coupons showed no indication of excessive corrosion or mass loss (less than the acceptance criteria of <0.05mil/yr)
- Areal density changes from -0.7% to +0.8%
Material Qualification Testing
- Sheet Produced Typically Exceeds Minimum Certified Value by Significant Margin
- We Perform All Neutron Attenuation Testing At Our Facilities In Penn State
- Tensile Coupon and ICP Analysis Testing Example Only: Not based on Fermi Ensure Consistent Material Performance Specific Areal Density.
- 100% Material Sampling (on all billets and insert blanks) 16 l June 27, 2018 l © Curtiss-Wright
Material Monitoring Program Coupon Surveillance Programs will be similar to previous Insert programs with enhancements to align with NEI 16-03
- Short Coupon Monitoring Program
- Full Insert Inspection Program Two Coupon Trees
- General and Galvanic Couples
- Bend Coupons Material Qualification Report Including Accelerated Corrosion Test Results
- Initial Accelerated Corrosion Testing includes RTA material with boron carbide loadings up to 25 v/o.
17 l June 27, 2018 l © Curtiss-Wright
Summary / Questions / NRC Feedback
- DTE plans to submit a LAR in 2018 to allow credit for neutron absorbing inserts in the SFP criticality analysis
- The LAR will allow elimination of an operating license condition that was imposed during license renewal
- Questions?
- Feedback?
Fermi 2 License Amendment Pre-Submittal Meeting 18