United States Nuclear Regulatory Commission - Protecting People and the Environment
Home > NRC Library > Document Collections > ACRS > Meeting Schedule and Related Documents > 2001 > Thermo-Hydraulic Phenomena Subcommittee Meeting

ACRS Thermo-Hydraulic Phenomena Subcommittee Meeting - June 12, 2001

ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
THERMAL-HYDRAULIC PHENOMENA SUBCOMMITTEE MEETING
ISSUES ASSOCIATED WITH CORE POWER UPRATES
JUNE 12, 2001
ROCKVILLE, MARYLAND

Contact: P. Boehnert (301/415-8065/"pab2@nrc.gov")

PRESENTATION SCHEDULE

  TOPIC SPEAKER TIME
I. Introduction G. Wallis, Chairman 8:30 a.m.
II. NRC Staff Presentations   8:40 a.m.
  A. Introductory Remarks NRC Staff  
      *Plant Power Uprates:
Scheduled and Planned
   
  B. ACRS Questions on Power Uprate Reviews NRC Staff  
      *PWR Vessel Internals Embrittlement    
      *RCS Depressurization:
Blowdown Forces
   
  C. Risk-Informed Review Considerations M. Rubin, NRR  
      *Risk Impact for Shutdown Operations    
      *Additional Questions (see Attached List)    
  D. Review of Codes for Uprated Plants    
      *Plans/Results of Plant Audits    
  E. Synergistic Effects Associated w/ Power Uprates F. Eltawila, NRR  
      *RES Research Program    
  F. Concluding Remarks NRC Staff  
  LUNCH   11:30 - 12:30 p.m.
III. ACRS Fellow Presentation A. W. Cronenberg,
ACRS Sr. Fellow
12:30 p.m.
    *Potential Margin Reductions Associated With Power Uprates    
  BREAK   2:00 - 2:15 p.m.
IV. GE Nuclear Energy Presentation J. Klapproth/
I. Nir/E. Eckert,
GE Nuclear Energy
2:15 p.m.
  1. Introduction(Open)    
  2. Extended Power Uprate Program (Closed)    
    *Background
- Scope and Content
*CPPU Topical
- Details of Methodology
*EM Codes
- Use of Realistic Methods
   
  3. Synergistic Effects (Closed)    
    - Impact on Margin Reduction    
  4. Concluding Remarks    
V. Subcommittee Caucus (Open)   4:15 p.m.
   
  • Follow-on Items from this Meeting
  • Future Actions
  • Committee Action
   
VI. Adjournment   4:30 p.m. (Est)

POWER UPRATE RISK-INFORMED REVIEW QUESTIONS

  1. Power uprates apparently lead to increased frequency of release of small amounts of radioactivity (short of causing fatalities). These increases are not reflected in increases in CDF or LERF. Do we need to have additional risk-informed acceptance criteria on the frequency of fission product releases of all magnitudes?
  2. Power uprates can be accommodated by reducing the margins between calculated values and the limits established for the figures-of-merit related to design basis accidents. Can the licensee use up all of these margins? Do we need to include uncertainty determination in the analyses to determine the probabilities associated with exceeding the limits?
  3. If power uprates lead to significant increases in burnup, do we reflect this in our PRA evaluations related to core melt behavior (e.g., ECCS success criterion) and fission product release?
  4. Will power uprates change the fission product source term associated with "gap release"? Will power uprates affect the "iodine spike" magnitude and the associated releases? Are these changes accounted for in the DBA analyses?
  5. Comparison of times required and times available before and after power uprates for operator actions in response to DBAs.
  6. Risk-Informed Uprate Review Considerations
    *Need for Assessment of Operational Data for Uprated Plants
    *Evaluation of Leibstadt Risk Study for Uprated Plants
Page Last Reviewed/Updated Tuesday, June 10, 2014