ML042080335

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M040721 - Meeting with ACNW (Slides)
ML042080335
Person / Time
Site: West Valley Demonstration Project, P00M-032, WM-00011
Issue date: 07/21/2004
From: Garrick B
NRC/ACNW, NRC/OCM
To:
References
+KBR1SISP20050613
Download: ML042080335 (47)
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Text

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ACNW MEETING WITH THE COMMISSION B. John Garrick July 21, 2004

a, Today's Agenda

  • Risk Insights Activities

- B.J. Garrick

  • Working Group Meetings

- Biosphere Dose Calculations

  • M.T. Ryan

- Geosphere Transport

  • G.M. Hornberger 2

Today's Agenda (Cont'd)

  • Other Committee Activities.

-NRC/CNWRA research

  • R.F. Weiner

-West Valley Site

  • M.T. Ryan
  • Closing Comments:

-B.J. Garrick 3

I-ACNW RISK INSIGHTS ACTiVITI ES B. John Garrick

Focus

  • Yucca Mountain Risk Baseline Report 5

Observations

  • Radiation dose is an indicator of health and safety risk and is favored as a basis for developing risk-informed guidelines
  • Risk-informed regulation concepts are being tested on real issues and facilities 6

Observations (Cont'd)

  • Population collective dose is limited as an indicator of risk for nuclear materials scenarios with small, longm term releases or small exposures to many people 7

Recommendations

  • Risk guidelines should be linked to radiation dose rather than health effects
  • Staff should move away from collective dose as a measure of risk 8

REVI EW OF YUUCCA MOUNTAIN HLW RISK BASELINE REPORT B. John Garrick

Risk Baseline Report Review

  • 2004 Risk Baseline Report

-details how risk considerations are factored into KTI reviews

-important element of issue resolution process 10

Risk Baseline Review (Cont'd)

  • Evaluated relative to waste isolation capabilities of repository system
  • Staff considered three categories of significance to waste isolation

-high, medium, low 11

Recommendations

  • Use risk insights to focus on most important KTI agreements

-translate risk-insights into specific guidance on prioritizing issue resolution 12

WORKING GROUP MEETINGS Michael T. Ryan

Purposes

  • Recent focus on Yucca Mountain technical issues
  • Learn about staff and DOE activities and plans
  • Identify technical issues that may warrant further study
  • Offer a vehicle for public participation 14

Areas Of Review

  • Previous working groups

-Transportation

-Performance confirmation

-TSPA

  • Recent working groups

-Biosphere dose assessments

-Geosphere transport 15

Biosphere Dose Assessment WG

  • Goal ... focused on metabolic models and environmental pathway analysis
  • Conducted in February 2004
  • Panel of six invited experts 16

Biosphere WG (Cont'd)

  • Discussions Focused On...

-technical bases necessary for biosphere dose assessments

-role of risk insights in the development of technical bases 17

a)

Biosphere WG:

Observations

  • Predicted doses are small, near background levels
  • No high-risk performance issues for the base case
  • Several conservatisms are present
  • Realism of calculations could be improved 18

Observations (Cont'd)

  • Igneous eruption could potentially have significant effect on risk estimates
  • Research should continue to focus on inhalation intake parameters and aerosol resuspension 19

GEOSPHERE TRANSPORT WORKING GROUP George M. Hornberger

Purposes

  • Goal ... To review expected behavior of radionuclides in aquifers at Yucca Mountain
  • Conducted in June 2004
  • Panel of four invited experts 21

Geosphere Transport:

Observations

  • Most of predicted dose from a few Radionuclides

-Np-237, 14129, and Tc-99

  • Flow paths, travel times, matrix diffusion, and retardation are important considerations 22

Observations (Cont'd)

  • Highly retarded radionuclides (i.e., Pu, Am) never arrive at compliance boundary
  • Calculated travel times for mobile radionuclides in aquifer -1 00s to 1 000s of years 23

Observations (Cont'd.)

  • Work by NRC, DOE, and others indicates that natural system is an effective barrier 24

Observations (Cont'd.)

  • Additional information could reduce uncertainty

-groundwater discharge

-matrix diffusion

-sorption coefficients

-water chemistry 25

Observations (Cont'd.)

  • Even modest Np retardation in alluvium delays arrival at compliance point past 10,000 years 26

CENTER FOR NUCLEAR WASTE REGU LATO RY ANALYSES PROGRAMSINIRC RESEARCH PROGRAMS Ruth F.l Weiner

Current Activities

  • Review of Selected CNWRA Programs

-March 4, 2004, letter report

-Review of RES Radionuclide Transport Research

-May 5, 2004, letter report 28

CNWRA Programs

  • ACNW Review Focused on:

-igneous activity

-spent fuel/water interactions

-corrosion studies

-post-closure drift stability

-pre-closure Safety Analysis (PCSA) Tool 29

CNWRA Programs (Cont'd)

  • ACNW Provided Comments on:

-inhalation models for exposure to volcanic ash

-use of uranium dioxide in dissolution studies (in progress) 30

CNWRA Programs (Cont'd)

-drift stability

-improVements and transparency of the Center's PCSA tool 31

PCSA Tool

  • Review of the PCSA Tool Showed:

-adequate modeling flexibility

-appropriate modeling of accident scenarios

-transparency

-traceability 32

Conclusions

  • Evaluated CNWRA work is addressing issues of importance to NRC
  • Evaluated CNWRA work continues to be of high quality 33

WEST VALLEY SITE Michael T. Ryan

Complex Site

  • Land Surrounding WVDP

-unrestricted use

  • Parts of WVDP

- restricted use

  • Burial Sites

-long-term license

-awaiting geologic repository 35

DOE Performance Assessment Approaches

  • To be Used to Demonstrate Compliance with LTR

-deterministic, bounding, and probabilistic analyses are planned 36

NRC StaffIs Independent Performance Assessment

  • Probabilistic in Nature
  • Uses Realistic Assumptions
  • ACNW Strongly Encourages Staffs Approach 37

ACNW Next Steps

  • Periodic Meetings with Involved stakeholders
  • Report on Progress to the Commission 38

CLOSING COMMENTS B. John Garrick

ACNW Action Plan

  • Undertake reviews of Commission-approved topics
  • Action Plan to be updated to reflect approved topics 40

Action Plan (Cont'd)

  • Working with NMSS Management on process improvements
  • Work with staff to identify predecisional topics for Commission approval 41

Future Activities

  • Working Group Meetings

-goal of one per quarter

-future subject areas...

  • Igneous activity (September 2004)
  • Health physics/radiation biology (December 2004) 42

Future Activities (cont'd)

  • West Valley performance assessment (CY 2005)
  • Support Commission adjudicatory technical staff 43

ABBREVIATIONS ACNW Advisory Committee on Nuclear Waste Am, Np, Pu Americium, Neptunium, Plutonium CNWRA Center for Nuclear Waste Regulatory Analyses DOE U.S. Department of Energy EIS Environmental Impact Statement 44

ABBREVIATIONS (Cont'd)

HLW High-level nuclear waste KTI Key technical issue LTR License Termination Rule NMSS Office of Nuclear Material Safety and Safeguards NYSERDA N.Y. State Energy Research Development Authority 45

ABBREVIATIONS (Cont'd)

PA Performance assessment PCSA Pre-closure safety analysis PRA Probabilistic risk assessment RES NRC Office of Nuclear Regulatory Research TSPA Total system performance assessment 46

ABBREVIATIONS (Cont'd)

WG Working group WVDP West Valley Demonstration Project 47

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