Analysis of Blending of Low-Level Radioactive Waste

Transcription

1 Analysis of Blending of Low-Level Radioactive Waste Briefing for Nuclear and Radiation Studies Board The National Academies James E. Kennedy, Sr. Project Manager Dr. Christianne Ridge, Sr. Systems Performance Analyst Environmental and Performance Assessment Directorate Division of Waste Management and Environmental Protection Office of Federal and State Materials and Environmental Management Programs July 20, 2010

2 Topics Key Messages Drivers for blending Blending proposal Summary of NRC actions and staff paper Intruder protection analysis Conclusions 2

3 Key Messages Limited access to Barnwell disposal facility Blending as a generator option Large-scale blending proposal NRC requirements and guidance Commission vote paper 3

4 US Ecology Hanford Commercial LLW Sites in U.S. Facility Waste Compact Restrictions Hanford, WA Class A, B, C 11 western states in 2 LLW Compacts only EnergySolutions, Clive Utah Waste Control Specialists EnergySolutions, Barnwell SC Clive, UT A only None, all US generators OK (NW and RM Compacts must approve) Barnwell, SC A, B, C SC, NJ, CT as of mid-2008 (Atlantic Compact) Operating facility Proposed facility Andrews Cty, Texas A, B, C Texas and VT only (Texas Compact) 4

5 Class B/C Disposal Access in U.S. (as of June 30, 2008) Other LLW compacts and unaffiliated States no disposal facility available Northwest and Rocky Mountain Compacts (AK and HI not shown) U.S. Ecology facility in Richland WA available. Atlantic Compact-- Barnwell disposal facility available. 5

6 Waste Classification 10 CFR Part 61 Subpart C performance objectives ensure safety Protection of an inadvertent intruder is one of the four performance objectives Intruder protection is the basis for waste classification tables LLW is Class A, B, C, or greater-than-class C Greater controls required for increasing hazard of waste classes 6

7 Ion Exchange Resins Reactor water, spent fuel pool, secondary side water Use to remove radionuclides, maintain water chemistry Significant Class B/C waste stream Flowable capable of being mixed into relatively homogeneous mixture 7

8 Waste Classification Table 10 CFR (short-lived radionuclides only) Radionuclide Concentration, Ci/m 3 Total of all radionuclides with < 5 yr half-life Col. 1 (Class A limit) Col. 2 (Class B limit) 700 n/a n/a H-3 40 n/a n/a Co n/a n/a Ni Col. 3 (Class C limit) Ni-63 in activated metal Sr Cs If concentration does not exceed column 1, waste is Class A. If concentration is > col. 1 and < col. 2, waste is Class B. If concentration is > col. 2 and < col. 3, waste is Class C. If > col. 3, waste is not acceptable for near-surface disposal 8

9 Blending of LLW Industry proposal to State of TN Ion exchange resins and other filter media from NPP s Waste class reduction Potential for mitigating impacts of Barnwell closure 9

10 Definitions Dilution Mixing waste with clean material Increases waste volume Potential release to environment Blending Mixing waste with waste No clean materials involved, no inherent volume change Disposal in licensed facility 10

11 Blending 11

12 Issues Significant stakeholder interest Disposal of Class B/C wastes Prior Commission statements re dilution Volume reduction Impact on new facility 12

13 Significant Actions Meetings with stakeholders Site visits Public meeting January 14, 2010 Federal Register Notice and opportunity for public comment Independent staff analysis Commission vote paper, April 2010 (SECY ) Commission meeting, June 17,

14 SECY , Blending of Low- Level Radioactive Waste Requested by Chairman Jaczko Completed April 7, 2010 Policy, safety and regulatory issues identified Four options presented Maintain status quo Implement risk-informed, performancebased position Further constrain blending Prohibit large-scale, off-site blending Staff recommendation is to risk-inform blending position four agency actions 14

15 Intruder Protection Waste classification concentration limits based on 500 mrem/yr intruder dose Differences between classification assumptions and current conditions may change estimated dose 15

16 Intruder Protection Part 61 Analysis Construction / Discovery Dust inhalation Gamma from waste Gamma from dust cloud Agriculture Gamma from contaminated soil Gamma from dust cloud Dust inhalation Plant ingestion (root uptake and foliar deposition) Animal product ingestion Groundwater evaluated separately 16

17 Blended Waste Part 61 Analysis Hypothetical Blending Scenario 17

18 Homogeneity Part 61 Analysis Hypothetical Blending Scenario 18

19 Staff Observations Meeting waste classification requirements alone may not demonstrate intruder protection Site-specific dose analyses could explicitly demonstrate intruder protection Modern disposal sites are likely to accommodate disposal of blended waste safely 19

20 Conclusions Large-scale blending is timely and real Stakeholder questions, concerns, and issues Risk-informed, performance-based approach recommended by staff Commission considering staff vote paper 20