Radiation Risk Assessment: Looking Beyond BEIR VII [Biological Effects of Ionizing Radiation] (Dec. 5)

• Charles Land, Ph.D., Honorary Chairman.  Senior Investigator, Radiation Epidemiology Branch, U.S. National Cancer Institute. "The Uncertain World of Radiation-Related Risk: Policy Implications at Low Doses."

Novice overview: 
LNT Theory - hard to gauge risks at low doses.  Need an extremely high exposure population size (e.g. 62 million) - so must extrapolate from high dose / low population exposure.  This extrapolation is linear.  Radiation assessment based on mean.

Dr. Land's technical summary:
The relationship between radiation dose and cancer risk is highly quantified but also uncertain, with many identifiable and quantifiable sources of uncertainty.  The dose-response relationship at very low doses is essentially unobservable, and therefore must be inferred somehow by extrapolation of observations pertaining to higher doses, adding a further layer of uncertainty.  How uncertainties are perceived depends very much upon one's point of view.  However, uncertainty analysis may provide a picture of radiation-related risk, as an uncertain quantity, that can serve as a common ground for discussion among interested parties with different viewpoints.

• Elisabeth Cardis, Ph.D., Chief, Unit of Radiation and Cancer, International Agency for Research on Cancer

Novice overview:
http://www.bmj.com/
Did a 15-country study of nuclear facility workers to have a larger population size, which is needed when studying low dose exposure.  Results: 1) Higher cancer risk than A-bomb (smoking skews results, but doesn't explain all risk); 2) One to two percent of cancer deaths were related to their workplace exposure.

Dr. Cardis's technical summary:
A multinational retrospective cohort study of cancer mortality among nuclear industry workers in 15 countries was conducted, using a common core protocol, to provide direct estimates of cancer risk following protracted low doses of ionizing radiation and to strengthen  the scientific basis of radiation protection standards for environmental, occupational, and medical diagnostic exposures.  The first results of this study, based on 407,391 nuclear industry workers individually monitored for external radiation with a total follow-up of 5.2 million person-years are presented.  Risk estimates are statistically compatible with the bases for current radiation protection standards.  They range from values lower than those based on linear extrapolation from the atomic bomb survivor data, up to values that exceed this extrapolation by a factor of five for cancers other than leukemia and by a factor of two for leukemia.  These results suggest that an excess cancer risk exists, albeit small, even at the low doses and dose-rates typically received by nuclear industry workers in this study.

• Mary Helen Barcellos-Hoff, Ph.D., Senior Staff Scientist, Life Sciences Division, Lawrence Berkeley National Laboratory

Novice overview:
Discussed studies of ionizing radiation effects on cell groups and between cell groups.  Radiation induces rapid extra-cellular signaling (crosstalk).  Carcinogens affect frequency and features of malignant progression, but multi-cells are effective at suppressing these.  Subjects irradiated with low doses actually saw fewer tumors than those with no radiation.

Dr. Barcellos-Hoff's technical summary:
Cell function in complex three-dimensional tissues is coordinated by soluble signaling peptides and by small molecules within the context of insoluble scaffolding provided by the extra-cellular matrix.  Recent studies have highlighted crosstalk between irradiated cells and non-irradiated bystander cells and have uncovered high frequency phenotypes of genomic instability in the progeny of irradiated cells that cannot be solely explained by direct radiation-induced mutation.  A model of radiation response based on the systems biology principles of network interconnectivity and spatial organization of these cellular phenotypes within the higher order structure of tissues and organisms will be discussed.

• David Brenner, Ph.D., Professor of Radiation Oncology and Public Health, Columbia University Medical Center

Novice overview:
Two studies were done to find out how to extrapolate radiation risks below epidemiologically tractable doses (measurable down to 10mfy - what about below this?).  BEIR VII (lead by the US) found a linear correlation - and that one can look at 10mfy and higher and simply extrapolate downward.  A French Academy study found that there is no or minimal risk below 10mfy, because the fewer cells affected can be controlled - apoptotic cells destroy themselves.  Questions arise though as to whether all cells behave the same way at low levels and whether 10mfy is the threshold.  An inutero study found that exposure to low doses (6-10mfy) does increase cancer risk.  6mfy equals one photon hit per one nucleus.  The cells talk to each other (not certain how), and those irradiated tell the others how to suppress the effects if they are hit.  So the first hit to a cell group is damaging, but future hits are less so.

Controversial issue - the two studies came to such differing conclusions.  Are societal issues playing into results?  75% of France's electricity is borne from nuclear power.  Dr. Brenner doesn't know if risks under 10mfy are higher, lower, or linear to those above 10mfy, but he does believe there is some risk.

Dr. Brenner's technical summary:
Within the past year, both the US and French National Academies published learned reports on the cancer risks associated with low doses of ionizing radiation.  The US report, BEIR-VII, concluded that "A comprehensive review of available biological and biophysical data led the committee to conclude that the risk would continue in a linear fashion at lower doses without a threshold and that the smallest dose has the potential to cause a small increase in risk to humans."  By contrast, the French Academies report concluded that, "At low doses and low dose rates of ionizing radiation, the pro-apoptotic effect dominates and the damaged cells, of which there are only a few, can be eliminated or controlled."  Two very different views of the effects of very low doses of radiation.  We will discuss how and why these two bodies came to such opposite conclusions, and reassess what we do  and don't know about cancer risks at very low radiation doses.

Nuclear and Radiation Studies Board Open Session (Dec. 6)

Mark Gilbertson, Deputy Assist. Sec., Environmental Cleanup and Acceleration, DOE-EM - "EM Update" (PowerPoint provided)

• Focus on risk reduction - workers, environment, public
• 114 sites in 31 states covering 2 million acres.  $6.2 billion (as of FY2004) with a federal and contractor workforce of 34,200.
• World's largest cleanup program - 20,000 canisters of HLW; 142,000 cubic meters of TRU waste (3,800 shipments to WIPP); 1.2m cubic meters of LLW/MLLW; 4,500 surplus facilities.
• Goal of EM has changed from managing risk to reducing risk.
  • Safety - the sooner the cleanup, the safer for workers
  • Accountability
• Timeline: 
  • As of Sept. 2004, 38 remaining sites. 
  • 2005-6 successes in closure of Rocky Flats, Mound, and Fernald.
  • 2008 - East Tennessee Technology Park
  • 2012 - Hanford River Corridor Project
  • 2020 - SRS waste tanks
  • 2025 - Complete cleanup of 108 of 114 sites
  • 2035 - Complete cleanup of all sites
• EM Projects:
  • Project Baseline Summaries - 77 "operations-funded" cleanup projects
  • Line Items - 6 construction projects
• Where going:
  1. Safety
  2. Deliver on commitments
  3. Base decisions on sound technical and business knowledge
  4. More rigorous planning (Rispoli is a project manager)
  5. Acquisitions
  6. Modify assumptions, etc., on new technology info.
  7. Communicate better (more transparent)
• 4 and 5 are covered in DOE Order 413.3 - Program and Project Mgmt. for the Acquisition of Capital Assets.  Strive for project risk mgmt. and the integration of project baselines.
• Goals:
  • Improve EM project performance to 90%
  • Better account for cleanup unknowns/uncertainties
  • Improve use of risk mgmt. plans and info
  • Appropriately train and certify Federal Project Directors
• Needs:
  • Regulatory relief
  • Innovation
  • Effective communication
• Working with NRC to ensure tanks at Hanford, SRS, and Idaho are cleaned.
• 3116 legislation - NRSB interim study coming out soon.  Expected to help with goals.

Q&A
Biggest technical challenge?

o       Groundwater and soil remediation (some success with barriers and pumps, but also see failures)
o       Removal of waste from tanks
o       Making sure use right technology to stabilize for long period (10,000 years).  Difficult to assure this.
o       Communication - real and perceived risks

Interim report on tank waste at SRS - decoupling?

o       Closing tanks with grout takes several years even after waste is removed.  Time to insert technology (e.g. Richland)

Sodium bearing waste at Idaho?

o       Will put out report in coming weeks to determine in future whether this goes to Yucca or WIPP.

What is the end point - Long-term Stewardship?

o       When EM stage concluding, transition to the Office of Land Management to monitor the site for as long as it takes to prove it is meeting the standards.
o       There are transition timelines and staff to ensure institutional knowledge remains.

Status of Hanford tanks?

o       Starting to clean some tanks - making progress on one or two that the state has bought off on.  But have 177, so baby steps.
o       Working within schedules of the Tri-party Agreement.  Stakeholders need to be involved in project managing to the tune of any new timelines.

Varied waste retrieval at Idaho?

o       Second pit.  There is a challenge there similar OU1 and Mound.
o       Worker risk - better to dig up and re-bury or leave in ground?

Rispoli's legacy?

o       Transparency - better understanding
o       Reinforce science aspect

Technical update on medical isotope production and low-dose program by:
- Kasia Mendelson, Director, Office of Global Nuclear Material Threat Reduction, DOE-NNSA
- John Pantaleo, Jr., Program Director, Isotope Program, Office of Nuclear Energy, Science, and Technology, DOE-NE
- Dr. Noelle Metting, Senior Radiation Biologist, DOE-SC

• Focus on cell and molecular biology
• Consistent with Dec. 5 symposium and notes

Christopher Kouts, Office of Systems Analysis and Strategy Development, DOE-OCRWM

• Mission - Manage and dispose of high-level radioactive waste (HLW) and spent nuclear fuel (SNF) in a manner that protects health, safety, and the environment; enhances national and energy security; and merits public confidence.
• Priorities - Submit license application for Yucca Mountain repository construction authorization.
• 122 sites in 39 states currently hold HLW and SNF destined for geologic disposal.
• Sources and quantities of HLW and SNF:
  • Commercial - 51,000 metric tons (MT) through 2004.  130,000 MT projected through 2055
  • DOE SNF - 2,500 MT
  • DOE HLW - 22,000 canisters to be vitrified through 2046
  • Surplus weapons plutonium - 50 MT
• Yucca capacity of 70,000 MT is statutory, not technical
• Nuclear waste history:
  • Pre-Nuclear Waste Policy Act of 1982:
    • Mid 1950s - Preliminary screening
    • 1957 - National Academy of Sciences (NAS) recommends geologic disposal
    • Early 1970s - Atomic Energy Commission (AEC) proposes different sites
    • 1975 - Energy Research and Development Agency (ERDA) begins search for sites
    • 1978 - Presidential Interagency Review Group initiated
    • 1980 - House and Senate can't agree on versions of passed nuclear waste bills
    • 1980-81 - DOE issues generic EIS and ROD for geologic disposal
• Nuclear Waste Policy Act of 1982
  • Site, construct, operate first repository for SNF and HLW
  • Site second repository
  • Nuclear waste fund will pay cost of program ($1 mil/kw hour)
  • Provisions for state/native participation (interim storage)
  • Study need for and feasibility of monitored retrievable storage (MRS)
• Nuclear Waste Policy Amendments Act of 1987
  • Directed DOE to characterize only Yucca for determination as to suitability for a repository.
  • Annulled DOE proposal to construct MRS at Oak Ridge, TN.
  • Established Office of Nuclear Waste Negotiator to seek voluntary host for MRS.
  • Cancelled second repository program and directed DOE to report to Congress b/t 2007-2010 on need for second site.
  • Established the Nuclear Waste Technical Review Board.
• Yucca located 100 miles NW of Las Vegas in Nye County.  Located on western boundary of the Nevada Test Site, a DOE facility.
• Yucca history:
  • Nuclear Waste Policy Act of 1982
  • 1987 - Yucca only site to be characterized
  • 1998 - Viability assessment complete
  • 2002 - DOE Secretary, then President recommend site.  Congress approves site.
  • July 2002 - DOE begins license application process
  • Future dependent upon NRC action:
    • Construction authorization hearings
    • Construction authorization (should occur 3 years from application date)
    • Updated license application
    • License to receive and possess waste
• Yucca images provided:
  • Exploratory studies facility portals
  • Subsurface reference design
  • Cutaway of a drift with three types of waste packages
  • Subsurface overview
  • Total system performance assessment
• License application
  • General info - overview and description of security programs
  • Safety Analysis Report:
    • Repository safety prior to closure
    • Repository safety after permanent closure
    • Performance confirmation program
    • Admin. and programmatic requirements
• Current Yucca Status
  • US Geological Survey emails - aware of problems and trying to rectify
  • Licensing Support Network review and certification
  • EPA proposed standard
• Transportation activities - Nevada rail line development:
  • DOE selected Caliente Corridor (approx. 300 miles, $2 billion cost) through Record of Decision.
  • Timeline:
    • Currently completing technical data collection along corridor.
    • Issue draft rail alignment EIS in FY 2006 (hold public hearings)
    • Issue final rail alignment EIS in FY 2007
    • Issue Record of Decision for rail alignment
    • Final rail line design and construction
• Canister Approach - Program redirection
  • Canister for transport, aging, and disposal (TAD) to minimize handling and limit need for multiple complex surface facilities.
  • Canister provides simplification in design, licensing, and construction.
  • SNF delivered to Yucca primarily in standard canisters, and there emplaced in waste packages for storage (fairly positive response from utilities and vendors on this).
• MRS/Interim Storage
  • Cannot be constructed until NRC issues license for construction of repository
  • Facility limited to 10,000 MTU until repository available - 15,000 MTU at any one time.
  • Siting follows same process as repository site selection (Governors and tribal leaders can veto)
  • Cannot be sited in NV.
• Reprocessing/Recycling
  • 1954 Atomic Energy Act encouraged commercial reprocessing of SNF
  • 1960s - Commercial reprocessing facilities begin development
  • 1966-75 - Reprocessing of SNF at West Valley, NY
  • 1977 - President Carter bans commercial reprocessing
  • 1981 - President Reagan reverses ban
  • 2005 - DOE Sec. Bodman state: "recycling technologies that do not produce separated plutonium must be considered not just a worthwhile, but a necessary goal."
• Utility litigation status:
  • 60 cases currently in court
  • Settlements - Exelon (others underway)
• FY 2006 Congressional Guidance
  • $450 million appropriated - $651 M in president's budget, $550 M passed in Congress.
  • Additional $50 million provided in Yucca budget to develop SNF recycling plan and site suitability
    • Site not limited to DOE, but voluntary
    • $20 M to be made available to site volunteers
    • Detailed plan due to Congress March 31, 2006
    • Initiate selection by June 30, 2006
    • Additional site targets identified in 2007
    • Begin construction of one or more facilities in 2010
• Cumulative shortfall between budgeted and appropriated funds for nuclear waste between FY 1995 - FY 2006:  $1.222 billion.
• Program status:
  • New Acting Deputy Director, Paul Golan
  • New Director nominated, Ward Sproat - Sens. Reid and Ensign have holds on his nomination
  • A re-evaluation of the program is underway

Q&A
Need for second repository?

o       Depends on needs in future, how much reprocessing occurs

How are funds appropriated for nuclear waste?

o       From the Nuclear Waste Fund for commercial waste
o       From 0508 for defense waste

What would happen with canisters from private fuel storage (PFS)?

o       Could come to Yucca, but would be replaced into disposal canisters, which would require a contract charge (now held in canisters and casks).

How to reprocess without separating plutonium?

o       No consensus approach - is being actively considered.

Possible to have integrated MRS and reprocessing facility?

o       Don't know yet.

Are you currently inspecting fuel at the sites?  If not, how could you verify contents of already sealed canisters when they arrive at Yucca?

o       Some presence at sites to ensure compatibility with NRC licensing requirements about what is deposited at Yucca.

Invited Comments on SNF management:

Dr. Thomas Cochran, Director, Nuclear Program, Natural Resource Defense Council (NRDC)

• EPA corrupted Yucca standards when they found that it leaks badly
• Current proposals intended to slow accumulation of SNF
  • Reprocessing using UREX+ and/or pyroprocessing
  • Transmutation using fast reactors
• Closed fast-reactor fuel cycle for transmutation is uneconomic, unreliable, unsafeguardable, unsafe, unworkable.
• So-called proliferation resistant reprocessing technologies actually increase the proliferation risks relative to the once-through fuel cycle (IAEA safeguards currently permit facilities to be built and operated in non-weapon states).
• NRDC solution:
  • Terminate proliferation risky R&D on fast reactors and pyroprocessing
  • Initiate search for second geological repository in US
  • Improve interim dry cask storage at reactor sites
  • Allow away-from-reactor storage for decommissioned reactors

John Parkyn, Chairman of the Board, PFS

• Private, interim storage facility for SNF (initiated in 1994 b/c saw that 1998 deadline wouldn't be met)
• 40,000 MTU capacity under current license (100 acres w/i 820-acre controlled area for 4,000 casks [200 per year])
• Eight utilities own PFS, LLC. (but open to all utilities for storage)
• Located on Goshute Reservation
  • West desert area of Utah
  • Low population area
  • No surface or groundwater nearby
  • Railway nearby
• History of PFS
  • 1997 - allied to NRC for license
  • 2000 - NRC safety hearings
  • Dec. 2001 - Final EIS and Safety Evaluation Report recommended license
  • April-July 2002 - NRC Environmental and Final safety hearings
  • Sept. 9, 2005 - NRC license vote
  • Dec. 5, 2005 - US Supreme Court denied review (UT's challenge)
• PFS includes new standards for storage and transportation
  • Improved storage cask technologies
  • Upgraded national rail standards
  • New rail car design
  • Enhanced security standards
• Benefits
  • Less expensive than on-site storage by indiv. utilities
  • Commitment only to space, not usage schedule
  • Includes shipping and storage, and decommissioning
• Looking ahead- user funded, so need commitments to begin building site
• Necessary now since Yucca progress slow and national interest in security of single site.  Lower cost than other options.

Dr. Alan Hanson, AREVA

• Open cycle "once through" strategy originally adopted to support nonproliferation objectives, but complicates waste disposal.
• Nuclear renaissance requires closed-cycle strategy to adequately handle waste increases
• Why reprocess?:
  • Repository optimization through HLW reduction (and heat load reduction).  Could increase Yucca loading by four times.
  • Energy security and resource conservation
  • Economics (cost effective)
  • Proliferation-resistance imperative
• Reprocessing results:
  • Early uranium + plutonium removal - within three years - avoids buildup of americium and Pu-241 decay. 
  • Treatment of low burn-up legacy fuel in dilution. 
  • Pu use in MOX destroys about 1/3 of original Pu and significantly degrades isotopic composition of remainder.

Public Comment:
Union of Concerned Scientists - Don't use highly-enriched uranium (HEU) for commercial use.
Radiopharmaceutical Industry - Need HEU until lowly-enriched uranium technology is commercially viable.

Green Peace

• Reprocessing in Europe and Japan show failures:
  • England - breakage, closure
  • Japan - about to start, but no need
  • Russia - no need commercially, but do need weapons-wise
  • France - stockpile increases
  • Germany - getting out of industry
• Green Peace agrees with Thomas Cochran (NRDC)
• http://www.stop-plutonium.org/

Public Citizen - AREVA presentation a pipe-dream because the technology is not even available yet.  Currently would require huge costs - a waste of taxpayer dollars.

 Environmental Management of Federal Facilities Web Page