ML090720708

Meeting Handouts for Pre-Application Meeting with Entergy Operations, Inc. (Eno), to Discuss Spent Fuel Criticality Amendment for Palisades Nuclear Plant

ML090720708
Person / Time
Site:	Palisades
Issue date:	03/12/2009
From:	Plant Licensing Branch III
To:
Wengert, Thomas J, NRR/DORL, 415-4037
References
TAC ME0708
Download: ML090720708 (9)

Text

PRE-APPLICATION MEETING WITH ENTERGY NUCLEAR OPERATIONS, INC. (ENO), TO DISCUSS SPENT FUEL CRITICALITY AMENDMENT FOR PALISADES NUCLEAR PLANT (TAC NO. ME0708)

March 12, 2009 March 12, 2009 1

Overview

• Recent submittal for Region I:

- no Carborundum credit

- fresh fuel assumed with soluble boron

- resulted in 2/4 checkerboard pattern

• This submittal:

- include burnup credit

- include some Carborundum credit

- include soluble boron credit

- improve the storage capacity of Region 1 March 12, 2009 2

Programs

• KENO-V.a, SCALE 4.4a, with 44 group library

- Bias and uncertainty evaluation will follow closely the method shown in recent submittals.

- Guided by NUREG-6698: 100 benchmark problems (including MOX), trending analysis, normality, description of applicability.

- A benchmark including fission products is not considered necessary at this time.

• An equivalency method is used. In CASMO-3, an equivalent amount of (in-fuel) boron is determined to represent the reactivity effect of fission products.

• The KENO-V.a model does not explicitly contain fission products.

• 5% Bu uncertainty adequate conservatism for this application March 12, 2009 3

Programs

• CASMO-3.

- Used to generate cross sections for the fuel cycle calculations.

- Will be used for generation of depletion inventories.

• NEMO and PRISM Topical Reports

- Will be used for tolerance calculations.

• Will include selected critical benchmarks March 12, 2009 4

Assembly Selection

• Selection of limiting assembly type

• What is modeled, what is omitted

- End details (top & bottom nozzles) omitted

- Guide bars included

- Grid spacers being evaluated

• Conservatively assume a nominal maximum uniform (average) planar enrichment over the axial length and cross sectional area of the assembly.

• Review of assemblies in the pool, what is expected

• Consider special items (pin holders, lights, dummy assemblies)

March 12, 2009 5

Bias and Uncertainty

• Follows the methods outlined in recent AREVA submittals.

• Methodology Bias:

- from benchmarking and trending analysis for KENO-V.a

• Manufacturing Tolerance:

- rack tolerances: ID of cell, cell thickness, pitch, Carborundum

- assembly tolerances: w/o, pellet density, pellet radius, clad thickness, GT/IT thickness, guide bar

• System Parameters:

- moderator temp, off center assembly placement, rack interface, non-fuel bearing can, fuel assembly type and history

• All appropriately combined for K95/95 March 12, 2009 6

Analytical Requirements & Assumptions

• Will follow closely with recent AREVA submittals.

• Abnormal occurrences

- tipping or falling of assembly

- de-boration of pool

- misplacement of fresh assembly in rack

- misplacement of fresh assembly adjacent to rack

- stuck assembly (with uplifting force)

- off center assembly (horizontal movement)

- straight deep drop, drop through accident

- significant objects dropped in pool

- other March 12, 2009 7

Analytical Requirements & Assumptions

• Burnup credit calculations:

- Explicit rack modeling with no leakage, or full reflection.

- design basis fuel assembly characteristics:

• 4.6 w/o

• active fuel length with no axial blankets

• no gadolinia bearing fuel rods

- soluble boron credit

- flat axial burnup profile at low burnups, explicit determination of the breakpoint, custom burnup profile used above the breakpoint.

- CASMO depletion performed with conservatively high moderator and fuel temperatures to maximize reactivity.

- 5% uncertainty on burnup.

March 12, 2009 8

Analytical Requirements & Assumptions

• Carborundum credit, derived from BADGER testing results.

• Appropriate swelling model March 12, 2009 9