ML063480028

Slides, Nine Mile Point 1 Alternate Source Term, from Nrc/Constellation Energy Meeting

ML063480028
Person / Time
Site:	Nine Mile Point
Issue date:	12/04/2006
From:	Constellation Energy Group
To:	Office of Nuclear Reactor Regulation
References
Download: ML063480028 (16)

Text

CKIT"1.

Agenda

• Introductions e NMP1 Design Overview e Limiting Design Basis Accident (DBA) Analyses e Suppression Pool pH Control e Technical Specification Revisions 2

Consteltation Attendees NA-IA A lllI'I I I ... . I TlllT L EIl 'I I II I ,II TITLE Todd Fiorenza NMP Design Eng'g Manager Glenn Stinson NMP Sr. Analyst Dennis Vandeputte NMP Sr. Licensing Engineer Jim Metcalf Polestar Applied Technology Phil Wenglowski CGG Nuclear Fuel Services Gerry Gryczkowski CGG Nuclear Fuel Services

NMPI Licensing Background

= .*. _ .. IL . _ _* . . .I III I I II I.

" Initial Operating License - 1969

" Full-Term Operating License - 1974

" Pre-GDC Plant

• AST Submittal Satisfies Commitment Made in GL 2003-01

Response

4

NMPI Design Overview

" BWR2 Reactor, 1850 MWt

-2 Main Steam Lines

" Mark I Containment

- DryweLl (inverted light bulb)

- Suppression Chamber (torus)

NMPI Design Overview Reactor Building (Secondary Containment)

- Encloses Primary Containment

- Houses ESF Systems

- Houses New and Spent Fuel Storage Facilities

- Poured Concrete up to Refuel Floor

- Metal Wall Panels and Roof Deck Above Refuel Floor

• Reactor Building Emergency Ventilation System (RBEVS)

- Maintains Negative Pressure in RB Post-Accident

- 2 Trains of Fans and Fitters (HEPA and Charcoal) 6

NMP1 Design Overview Control Room

- Located in Southeast Corner of Turbine Building

- Positive Pressure Maintained During Normal Operation and Post-Accident

- Maximum Measured Inleakage of 45 scfm Control Room Air Treatment System (CRATS)

- Filters Intake Air Post-Accident (HEPA, Charcoal)

- Initiates Automatically on LOCA, MSLB, or High Radiation in Intake Air

Limiting DBA Analyses DBAs Analyzed

- Loss of Coolant Accident (LOCA)

- Main Steam Line Break (MSLB) Accident

- Refueling Accident

- Control RodDrop Accident (CRDA)

• Regulatory Guide 1.183 Conformance 8

Limiting DBA Analyses

• New Atmospheric Dispersion Factors (X/Q values)

- Based on on-site meteorological data collected from 1997 through 2001

- PAVAN and ARCON96 computer codes used 9

Limiting DBA Analyses Loss of Coolant Accident (LOCA)

- EvaLuation Methodology

- Radionuclide Release Pathways

• Release Inputs and Timing

• Transport Inputs

• Removal Inputs

- Single Failure Considerations

- Conservatisms 10

Limiting DBA Analyses p Main Steam Line ,Break (MSLB) Accident

- Revised reactor coolant specific activity limits consistent with ITS

- Instantaneous ground level puff release dispersion factor for Control Room

- No credit for CRATS filtration

- Dose. conversion factors per Table 2.1 of FGR-1 1 11 r

Limiting DBA Analyses Refueling Accident

- Post-shutdown 24-hour decay period assumed

- Instantaneous release with no credit for secondary containment

- No credit for RBEVS or CRATS filtration 12

Limiting DBA Analyses Control Rod Drop Accident (CRDA)

- Two cases considered

" Release via main condenser leakage

" Release via mechanical vacuum pump No credit for CRATS filtration 13

Suppress~ion Pool pH ControL 4

° Credit for sodium pentaborate solution addition by the Liquid Poison System (LPS)

• Suppression pool pH calculation performed using methodology approved by NRC for Grand Gulf

• Evaluated suitability of LPS to perform post-LOCA pH control function

• Reviewed procedural guidance for post-LOCA LPS injection.

14

Technical Specification Revisions e New Definitions - Dose Equivalent 1-131; Recently Irradiated Fuel

• Require LPS Operability in Hot Shutdown e Revised RCS Coolant Activity Limits and Surveillance Requirements

" Relaxed Secondary Containment, RBEVS, and CRATS requirements

" Delete License Condition 2.C. (3) 15

Questions?

16