ML21036A015
| ML21036A015 | |
| Person / Time | |
|---|---|
| Issue date: | 02/11/2021 |
| From: | NRC/OCM |
| To: | |
| References | |
| M210211 | |
| Download: ML21036A015 (60) | |
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Spent Nuclear Fuel Dry Storage Urgent Problems and Solution Donna Gilmore, SanOnofreSafety.org NRC Commission Meeting, February 11, 2021 Regulatory Framework for Dry Cask Storage & Transportation of Spent Nuclear Fuel and Related Research Activities
Transporting uninspected thin-wall canisters across the country will no more solve our nuclear waste problems than rearranging the deck chairs on the Titanic would have stopped it from sinking.
SanOnofreSafety.org 2
Titanic sinking. Willy Stwer, 1912, via Wikimedia Commons
SanOnofreSafety.org 3
Recommendations Step One Require thick-wall maintainable, transportable storage casks before thin-wall canisters fail (which maybe soon). Swiss use high standard casks Orano/Areva TN24GB & TN24BHL/BH Castor V/19 & V/52 https://sanonofresafety.org/swiss/
Require ASME N3 Nuclear Pressure Vessel certification for storage and transport containment of spent nuclear fuel and high level radioactive waste.
Require hot cell dry fuel handling system at ISFSI waste storage sites.
Stop decommissioning fund disbursements and thin-wall canister approvals. Thick-wall casks are less expensive considering maintainability, life span, and reduced risks of nuclear disasters that can cause evacuations, radioactive contamination, and economic and security instability.
Step Two (Must do Step One before Step Two)
Store thick-wall casks in air cooled buildings for environmental and security protection, away from coastal and flood risks.
Swiss Solution
Unsafe thin-wall nuclear waste canisters must be replaced.
When youre in a hole - quit digging.
NRC should approve only thick-wall metal dry storage casks (10 to over 19 thick) designed to be inspected, maintained, repaired & monitored in a manner to PREVENT radioactive releases, criticalities & hydrogen explosions.
Only proven world standard bolted lid thick-wall metal cask systems can meet minimum American (ASME N3) nuclear dry storage and transport containment safety standards now.
Current unsafe uninspectable welded thin-wall canisters are vulnerable to short-term cracking and do not meet safety codes.
Sandia 2019 DOE Technology Gap Report. https://doi.org/10.2172/1592862 Even after decades of trying, there are no real solutions - only unsubstantiated hope - and were running out of time.
Thin-wall canisters do not meet NRC and Nuclear Waste Policy Act (NWPA) requirements for monitored retrievable spent nuclear fuel.
No pressure monitors or pressure relief valves, and no other method in place to prevent or stop major radiological releases from canisters.
SanOnofreSafety.org 4
1/2 thick thin-wall canister
SanOnofreSafety.org 5
Only thick-wall casks can meet safety requirements Safety Features Thin canisters Thick casks Thick walls 1/2-5/8 10- 19.50 Wont crack
Ability to repair, replace seals
Ability to inspect (inside & out)
Monitor to prevent failure
ASME N3 storage & transport
Defense in depth (redundancy)
Store in concrete building
Gamma/neutron protection With concrete vented overpack
Transportable unknown w/o inspection
Market leader U.S.
World Thick Cask Thin Canister
SanOnofreSafety.org 6
Fukushima thick-wall casks survived 2011 earthquake and tsunami
As long as NRC allows unsafe dry storage standards, quality vendors with quality products will have problems competing against inferior products
For example, Southern California Edison refused to require high quality standards. They refused to solicit thick-wall cask bids and used flimsy excuses to justify their decision.
Orano/Areva sells high quality thick-wall casks, but wont compete with themselves against their thin-wall lower standard products.
The Orano/Areva thick-wall casks currently used in the U.S. are not their top of the line casks. They had some design features that caused premature rusting of seals.
An Areva thick-wall cask is being used for the high burnup demonstration project.
CASTOR vendor GNS has continuous interest in the U.S. market and is high quality. GNS filed the package design approval application for their cask type CASTOR geo69 according to 10CFR71 with the NRC. The geo69 is designed to solve the problem of pool cranes that could not handle the thick cask weight. It still has the other high quality CASTOR features. The CASTOR V/21 (an older model) was used to justify dry storage in the U.S.
Both Orano/Areva and CASTOR thick-wall casks have been used in the U.S. for decades - longer than the thin-wall canisters.
The Swiss selected only top of the line casks from Orano/Areva and GNS.
They rejected the Holtec thick-wall cask design.
SanOnofreSafety.org 7
SanOnofreSafety.org 8
DOE Technology Gap Report Priority #1 risk: SHORT-TERM through wall cracks in thin-wall welded canisters (Sandia Lab)
Gap Priority 1: Welded canisters - Atmospheric Corrosion, short-term risks of through-wall cracks Focus only on chloride induced stress corrosion cracking.
[Report ignores earthquake risks with partially cracked canisters and ignores option of replacing canisters with thick-wall casks.]
Gap added: Consequence Assessment of Canister Failure poorly understood and of primary importance.
Raised Priority: Fuel Transfer Options -- fuel should be able to be transferred without returning to the pool for inspection and transfer.
Recent work on the Thermal Profile and Stress Profile gaps indicate that the fuel should be able to be transferred without returning to the pool for inspection and transfer. This priority has been raised recognizing the need for data to support a surface facility design concept for opening a cask for inspection or repackaging
[Report recognizes need for dry handling (hot cell) facility at interim storage sites, but does not address need to replace canisters at existing sites prior to transport or failure.]
Gap Analysis to Guide DOE R&D in Supporting Extended Storage and Transportation of Spent Nuclear Fuel: An FY2019 Assessment SAND2019-15479R, December 23, 2019 https://www.osti.gov/servlets/purl/1592862/
Microscopic cracks
Transport not a straight path forward Cannot inspect canisters or contents to ensure integrity for transport.
NRC RAI 2-1: MPCs [thin-wall canisters],
with degraded conditions exceeding surface defects equal to or greater than 2mm depth, will be identified prior to transport. 10 CFR 71.71 and 71.73
NRC RAI 7-1..confirm..analyzed configuration of stored high burnup fuel
[HBF] has been maintained throughout the renewed storage period of the MPC prior to transport. 10 CFR 71.55(e), 71.73 & 71.85(a)
Response to 2nd Request for Additional Information, Holtec International, Docket No. 71-9373 HI-STAR 190 Transportation Package 2/26/2017 (ML17031A363)
Unknown if normal train vibrations will cause fuel rod failure.
Interim Storage Plans (CIS): return leaking canisters to sender.
Sender has no method to handle leaking canisters.
Limit to how long leaking canister can stay inside transport cask before overheating.
Canisters may need decades of cooling before meeting transport regs.
NRC should not approve transport casks until issues resolved.
SanOnofreSafety.org 9
SanOnofreSafety.org 10 One canister holds roughly the Cesium-137 released from 1986 Chernobyl disaster Robert Alvarez
This is a NOW problem We cannot kick these Chernobyl cans down the road any longer. Consequences are too high.
No plan in place when something goes wrong.
Need dry transfer system (hot cell) facility to replace canisters.
None in the U.S. large enough or designed for this.
Spent fuel pools not a proven option. Sites either have no spent fuel pools or fuel is too hot to return to pools. No welded thin-wall canisters ever unloaded in pools. Edison CNOs admit: cannot unload fuel back into pools.
Proposed solution to store breached canister in sealed thick metal overpack is not an option. Fuel will overheat due to loss of air cooling.
Once cracks start in canisters, cracks can grow though the wall in only 16 years. NRC 8/5/2014 Thin-wall canisters are already up to 32 years old (1989).
U.S. Canisters and Casks Inventory DOE June 2013 https://sanonofresafety.files.wordpress.com/2018/07/d32-caskinventorybystate2018-07-14a.pdf
Other sources and more information and references in D. Gilmore Comments to NUREG-2224 High Burnup Fuel Storage and Transport, 2018 https://www.nrc.gov/docs/ML1826/ML18269A037.pdf SanOnofreSafety.org 11 Swiss Zwilag Hot Cell
Swiss Zwilag Hot Cell (Dry Transfer System)
Inspect or transfer fuel to new cask SanOnofreSafety.org 12 https://www.zwilag.ch/en/hot-cell-_content---1--1056.html
NRC & EPRI claim not enough humidity at San Onofre for corrosion. Ignore frequent fog, surf, on-shore winds SanOnofreSafety.org 13
SanOnofreSafety.org 14 New Holtec UMAX system lids corroding Metal sprays on top of lower air vents is an attempt to stop corrosive Seagull poop from sliding inside air vents. Seagull poop is highly corrosive to stainless steel.
SanOnofreSafety.org 15 EPRI cherry picked data to reach false conclusions about canister lifespan EPRI falsely claimed it would be 80+ years before cracks can grow through canister walls.
Ignored crack initiating coastal conditions
Claimed insufficient moisture at San Onofre and Diablo Canyon to dissolve salt particles, in spite of frequent fog and on-shore coastal winds along Pacific Coast.
Ignored low enough temperature on 2-year old Diablo Canyon canister for moisture to stay on surface and dissolve salts.
EPRI found corrosive salts on canisters. No way to know cracking condition of canisters.
Ignored South Africa Koeberg tank that leaked in only 17 years
Koeberg cracks up to 0.60 long. Most thin-wall canister only 0.50 to 0.65 thick.
Koeberg tank is comparable component to thin-wall canisters NRC 8/5/2014 Used assumptive words over 254 times in EPRI report
Assume (69), expected (38), uncertainty (10), estimate (18), general (11), model (101), approximat (7)
Critique of EPRI Flaw Growth and Flaw Tolerance Assessment for Dry Cask Storage Canisters, D. Gilmore, 5/17/2015 https://sanonofresafety.files.wordpress.com/2013/06/epri-critiqueandkoebergplant2015-05-17.pdf Flaw Growth and Flaw Tolerance Assessment for Dry Cask Storage Canisters. EPRI 3002002785, 10/14/2014 https://www.epri.com/research/products/000000003002002785
Diablo Canyon: corrosive coastal environment SanOnofreSafety.org 16
SanOnofreSafety.org 17 Holtec President Kris Singh admits cannot repair canisters It is not practical to repair a canister if it were damagedif that canister were to develop a leak, lets be realistic; you have to find it, that crack, where it might be, and then find the means to repair it; we think its not a path forward.
You will have, in the face of millions of curies of radioactivity coming out of canister; we think its not a path forward.
Dr. Kris Singh, Holtec CEO & President http://youtu.be/euaFZt0YPi4
Holtec canisters damaged due to inferior engineering design Both Holtec HI-STORM UMAX and above ground Holtec systems unavoidably damage canisters during downloading into carbon steel lined concrete casks and storage holes.
Stainless steel canister walls are scraped, scratched or gouged against carbon steel protrusions inside storage casks and storage holes.
Carbon particles are embedded in canisters during downloading process from carbon steel protrusions in UMAX system and from vertical channels in above ground systems. No evaluation by NRC.
These are triggers for stress corrosion cracking and shortened lifespan.
Problem due to poorly engineered Tarzan-like swinging downloading system combined with narrow clearances.
Cannot be corrected with procedures. Cannot view canister hole when downloading. Clearances too tight and lack of precision loading system.
Holtec and NRC have no solutions, but continue use of these systems.
Similar or worse damage will likely happen when unloading (and reloading).
SanOnofreSafety.org 18
Cannot find or characterize cracks with cameras - only can see some precursors Gouges in canister walls. Crack growth unknown.
Impossible to examine & eliminate surface defects per ASME code, NRC Senior Inspector Lee Brookhart.
The original [Holtec] FSAR statement for no scratches mirrored the CoC/TS design basis that no scratches would ensure the code adherence to ASME Section Ill. Essentially, the change is adding an alternative to the code to not have to do inspections and repair these new defects. Alternatives to the code can only be done via license amendment. [NRC allowed continued loading without license amendment]
ASME Section Ill NB-2538, "Elimination of Surface Defects" requires that defects are required to be examined by either magnetic particle or liquid penetrant method to ensure that the defect has been removed or reduced to an imperfection of acceptable size.
Instead of doing that (which I understand is impossible) which would maintain code compliance, the 72.48 deviates using a calculational method to bound the defect.
The only "method" that should be used to disposition these defects is some method allowed or described in the BPVC code or the licensee would need an alternative to the code to maintain compliance with the regulatory licensing basis.
NRC Response to NRC question on ASME Code Application, 3/25/2019 https://sanonofresafety.files.wordpress.com/2019/10/ml19261a089foia-p180-186asme-non-comphilite.pdf SanOnofreSafety.org 19 San Onofre Holtec UMAX
SanOnofreSafety.org 20 STOP exemptions to ASME N3 NRC exemptions result in thin-wall canisters that cannot be inspected or maintained to ensure safe short-term or long-term dry storage and transport Cannot inspect inside or out for cracks & other major defects Cannot repair or maintain to prevent cracks Cannot monitor adequately to PREVENT short-term failure (e.g., no pressure monitoring or pressure relieve valves)
Not safe against earthquakes (unknown cracks inside & outside)
No backup plan in place to stop or prevent major radioactive releases Most countries use thick casks that can meet ASME N3 standards
Switzerland, Germany, Belgium Czech Republic, France, Italy & others.
Why demand the ASME mark. https://www.asme.org/certification-accreditation/why-demand-the-mark American Standards of Mechanical Engineers ASME N3 certification for nuclear pressure vessels for both storage and transportation containments of spent nuclear fuel and other high level nuclear waste.
N3 Demand ASME N3
SanOnofreSafety.org 21 NRC not evaluating most thin-wall stainless steel canister cracking risks Triggers for cracking (partial list)
Chlorides (moist salt air, potash, other chlorides)
Carbon particles Gouges, scrapes, scratches Poor engineering of canister downloading causing scrapes, gouges &
scratches in canister walls.(e.g., Holtec subterranean & above ground systems)
Manufacturing defects Pitting Mishandling Bird poop Outlet air vent Inlet air vent
SanOnofreSafety.org 22 Some aging canisters at risk for cracks and leaks Loaded Age (2021)
Calvert Cliffs 1993 28 years Rancho Seco 2001 20 years Oyster Creek 2002 19 years San Onofre 2003 18 years Indian Point 2008 13 years Diablo Canyon 2009 12 years Most U.S. thin canisters in use less than 16 years 2-page Commercial Canister/Cask DOE inventory, 6/30/2013 [DOE has not updated inventory]
https://sanonofresafety.files.wordpress.com/2018/07/d32-caskinventorybystate2018-07-14a.pdf
SanOnofreSafety.org 23 Unknown: How many fuel assemblies damaged?
Explosion Risks (partial list)
Hydrogen Gas explosion risks Spent fuel exposed to air in pool or dry storage can result in hydrogen gas explosions.
Evidence claiming no explosion risk, ignore hydrides Hydrides in both zirconium cladding and uranium fuel increases at moderate burnup levels Zirconium hydride gas/powder ignites at 270 degrees Celsius Zirconium powder used to make fireworks ignite.
Water remaining after drying converts to hydrogen from irradiation.
Canisters may over pressurize, but have no pressure monitors or pressure relief valves. Unknown amount of water in canisters.
Fuel can go critical if exposed to unborated water NRC states there will not be a criticality by assuming there will never be through-wall cracks. Not credited to prevent criticality if exposed to water. Boron in canisters only for loading from pool to dry storage.
(NRC, Holtec).
Explosion risk information & references (NUREG-2224 Comments, D.Gilmore) https://www.nrc.gov/docs/ML1826/ML18269A037.pdf SanOnofreSafety.org 24
SanOnofreSafety.org 25 Ore Hydrogen explosion risk increases at medium burnup
SanOnofreSafety.org 26 Significant high burnup fuel cladding embrittlement in dry storage M.C. Billone, T.A. Burtseva, and Y. Yan, Argonne National Laboratory September 28, 2012 the trend of the data generated in the current work clearly indicates that failure criteria for high-burnup cladding need to include the embrittling effects of radial-hydrides for drying-storage conditions that are likely to result in significant radial-hydride precipitation...
A strong correlation was found between the extent of radial hydride formation across the cladding wall and the extent of wall cracking during RCT [ring-compression test] loading.
Ductile-to-Brittle Transition Temperature for High-Burnup Zircaloy-4 and ZIRLO' Cladding Alloys Exposed to Simulated Drying-Storage Conditions http://pbadupws.nrc.gov/docs/ML1218/ML12181A238.pdf
SanOnofreSafety.org 27 HBF: Unknown failure limits following storage Mike Billone, Yung Liu, Argonne National Laboratory, November 20, 2013:
Newer Zirconium alloy claddings (Zirlo and M5) degrade faster with high burnup fuel (HBF) than earlier claddings Data needs Tensile properties of HBU M5 and ZIRLO' cladding alloys Failure limits for all cladding alloys following drying and storage Radial hydrides can embrittle cladding in elastic deformation regime Ductile-to-Brittle Transition Temperatures for High-Burnup PWR Cladding Alloys Mike Billone and Yung Liu Argonne National Laboratory U.S. NWTRB Winter Meeting November 20, 2013, DOE Slide Presentation https://www.nwtrb.gov/docs/default-source/meetings/2013/november/billone.pdf?sfvrsn=7
Nuclear Waste Technical Review Board recommendations for short-term and long-term storage Spent nuclear fuel and its containment must be maintained, monitored, and retrievable in a manner to prevent radioactive leaks and hydrogen gas explosions.
Need pressure monitoring and pressure relief valves.
NRC allows exemptions to these and other ASME requirements for thin-wall canister pressure vessels.
Need to determine amount of water in canisters. Concerned about explosion risks for storage and transport.
Dec. 2017 NWTRB Spent Nuclear Fuel Report to Congress and DOE No technology to make geological repositories work short-term or long-term, even for 20 years.
No idea how they will ever have the technology.
May 2018 NWTRB Geological Repository meeting (nwtrb.gov)
SanOnofreSafety.org 28
Swiss Solution for Thick Cask Storage SanOnofreSafety.org 29 https://www.zwilag.ch/en/cask-storage-hall-_content---1--1054.html
SanOnofreSafety.org 30 Only thick-wall casks can meet safety requirements Safety Features Thin canisters Thick casks Thick walls 1/2-5/8 10- 19.50 Wont crack
Ability to repair, replace seals
Ability to inspect (inside & out)
Monitor to prevent failure
ASME N3 storage & transport
Defense in depth (redundancy)
Store in concrete building
Gamma/neutron protection With concrete vented overpack
Transportable unknown w/o inspection
Market leader U.S.
World Thick Cask Thin Canister
Donna Gilmore SanOnofreSafety.org donnagilmore@gmail.com
SanOnofreSafety.org 32 Background Slides
SanOnofreSafety.org 33 Two-year old Diablo Canyon Holtec canister has conditions for cracking Temperature low enough to initiate cracks in 2 years
<85°C (185°F)
Moisture dissolves sea salt - one of many triggers for corrosion and cracking
SanOnofreSafety.org 34
SanOnofreSafety.org 35 Problems with U.S. thin-wall stainless steel dry storage canisters Not maintainable Cannot inspect exterior or interior for cracks Cannot repair cracks Not reusable (welded lid)
No warning BEFORE radiation leaks Canisters not ASME N3 certified NRC allows exemptions from ASME standards No defense in depth Concrete overpack vented to prevent over heating Unsealed damaged fuel cans No current plan for failed canisters Early stress corrosion cracking risk Inadequate aging management plan
SanOnofreSafety.org 36 Thick casks designed for longer storage
Market leader internationally
Maintainable
Inspectable
Replaceable parts (metal seals, lids, bolts)
Double bolted thick steel lids allow reloading without destroying cask
Over 40 years in service with insignificant material aging.
Some currently licensed and used in U.S. (18 to 30 month process for new or amended license)
Vendors wont request NRC license unless they have customer
Thick cask body forged steel or thick ductile cast iron (10 to 19.75)
Early warning before radiation leak (remote lid pressure monitoring)
Cask protects from all radiation, unlike thin steel canisters.
No concrete overpack required (reduced cost and handling)
No transfer or transport overpack required (reduced cost and handling)
Stored in concrete building for additional protection
Used for both storage and transportation (with transport shock absorbers)
ASME N3 & international cask certifications for storage and transport
Damage fuel rods sealed (in ductile cast iron casks)
Over 3200 US uninspectable thin-wall stainless steel welded canisters Thin-wall (1/2 to 5/8 thick) stainless steel canister vendors: Holtec, NAC and Transnuclear VSC-24 1 thick carbon steel canisters were discontinued, but in use at Arkansas, Palisades and Point Beach Japan was able to open thick-wall casks after Fukushima and found aluminum fuel baskets were starting to degrade. Unknown status of U.S. fuel baskets (aluminum or stainless steel).
US has older stainless steel baskets, but now standardizes on aluminum baskets. No US fuel baskets have been inspected.
Baskets critical to maintaining fuel assemblies.
Holtec BWR basket holds up to 68 smaller fuel assemblies. PWR basket normally hold 24, 32 or 37 larger fuel assemblies.
Up toSanOnofreSafety.org 37
SanOnofreSafety.org 38 San Onofre between Ocean & I-5 freeway 73 Holtec UMAX & 51 Areva NUHOMS canisters
SanOnofreSafety.org 39 How many cracks in thin-wall canisters?
No one knows No one knows how many cracks or size of cracks in any of the over 3200 canisters Diablo Canyon canister has all conditions for cracking in 2-year old canister (salt & moisture) (EPRI)
Cracks can grow through wall 16 years after crack starts (NRC)
Koeberg tank leaked in 17 years. Cracks over 0.61 (NRC). Thin-wall canisters only 0.50 or 0.625 thick (NRC)
Cannot inspect canister for cracks after fuel loaded.
Requires dye penetrant per ASME codes
SanOnofreSafety.org 40 No plan for cracking or leaking canisters License requires returning fuel to pool, but never been done with thin-wall canisters Hotter fuel cannot be unloaded back into pool Results in reflooding problem, yet NRC ignoring this Plan to destroy empty spent fuel pools NRC false assumption nothing can go wrong in dry storage Pool is only on-site current option to replace defective canisters Hot cell (dry fuel handling facility) is only other option
SanOnofreSafety.org 41 Hot Cell is only other option Idaho Test Area North (TAN) hot cell destroyed in 2007 No other U.S. hot cell large enough to replace canisters No plans to build hot cell Assumes nothing will go wrong
SanOnofreSafety.org 42 No warning before major radiation releases from thin-wall canisters No early warning monitoring Remote temperature monitoring not early warning No pressure or helium monitoring Thick casks have continuous remote pressure monitoring - alerts to early helium leak.
No remote or continuous canister radiation monitoring Workers walk around canisters with a radiation monitor on a stick once every 3 months.
Thick casks have continuous remote radiation monitoring NRC refuses to share or require outlet air vent radiation monitoring After pools emptied, NRC allows Removal of all radiation monitors Elimination of emergency planning to communities - no radiation alerts Removal of fuel pools (assumes nothing will go wrong with canisters)
Microscopic cracks
Fuel needs to cool for over a decade before safe to move to dry storage NRC approving amendments for unsafe heat loads in dry storage - double the previous heat loads High heat can damage fuel rods - unknown condition Fuel too hot to return to pools SanOnofreSafety.org 43
SanOnofreSafety.org 44 German interim storage over 40 years
SanOnofreSafety.org 45 Thick casks used worldwide
SanOnofreSafety.org 46 NRC license excludes aging issues Ignores issues that may occur after initial 20 year license, such as cracking and other aging issues Refuses to evaluate thick casks unless vendor applies Requires first canister inspection after 25 years Allowing 5 years to develop inspection technology Requires inspection of only one canister per plant That same canister to be inspected once every 5 years Allows up to a 75% through-wall crack No seismic rating for cracked canisters No replacement plan for cracked canisters Approves destroying fuel pools after emptied No money allocated for replacement canisters NRC aging management (NUREG-1927 rev. 1) not enforced
SanOnofreSafety.org 47 Consolidated Interim Storage (CIS)?
Legal challenges likely will delay or stop new sites indefinitely Shimkus 2018 H.R. 3053 NWPA Amendments and similar bills make problem worse 1.
Allows license transfer to federal government at existing sites 2.
Removes safety requirements needed to prevent major leaks 3.
Removes site specific environmental requirements 4.
Removes oversite of DOE (existing DOE waste sites leak!)
5.
Removes state, local, public rights to oversite, input, transparency 6.
Removes other federal, state and local rights (land, utilities, etc.)
7.
Ignores current storage and transport safety issues 8.
Removes cost analysis requirements for waste transport & storage 9.
Ignores transport infrastructure safety issues
- 10. Inadequate funding for storage and transport (becomes discretionary)
None of these issues discussed in House hearings!
SanOnofreSafety.org 48 Roadblocks to moving waste
Yucca Mountain geological repository issues unresolved
DOE plan: Solve water intrusion issue 100 years AFTER loading nuclear waste
Inadequate capacity for all waste, not designed for high burnup fuel
Numerous technical, legal and political issues unresolved
Congress limited DOE to consider only Yucca Mountain
Funding of storage sites unresolved
Communities do not want the waste
NWTRB says no technology to make any geological repository work
False promises & leaking DOE waste sites
WIPP repository leaked within 15 years - broken promises to New Mexico
Hanford, WA, Savannah River and other sites leaking
States have no legal authority over radiation safety - only cost and permits
Transport infrastructure issues, accident risks, cracking canisters
High burnup fuel over twice as radioactive, hotter, and unstable
Zirconium cladding more likely to become brittle and crack -- eliminates key defense in depth. Radiation protection limited to the thin stainless steel canister. Concrete overpack/cask only protects from gamma and neutrons.
Inspection of damaged fuel assemblies is imperfect
SanOnofreSafety.org 49 Condition of existing canisters unknown No technology exists to inspect canisters for cracks Most thin canisters in use less than 20 years Wont know until AFTER leaks radiation Similar steel components at nuclear plants failed in 11 to 33 years at ambient temperatures ~20°C (68°F)
Crack growth rate about four times faster at higher temperatures 80ºC (176°F) in wicking tests compared with 50°C (122°F)
Crack initiation unpredictable Cracks more likely to occur at higher end of temperature range up to 80°C (176°F) instead of ambient temperatures Canister temperatures above 85°C will not crack from marine air -
chloride salts wont stay and dissolve on canister Many corrosion factors not addressed. NRC focus is chloride-induced stress corrosion cracking (CISCC).
SanOnofreSafety.org 50 Game Changer Indefinite on-site storage 2014 NRC continued storage decision*
100+ years on-site storage Reload canisters every 100 years No other storage sites on horizon Canisters may fail in 20 to 30 years Some may already have cracks Cannot inspect for or repair corrosion and cracks No warning until after radiation leaks into the environment Diablo Canyon Holtec thin canister has conditions for cracking after only 2 years!
No replacement plan for failure
- GEIS analyzed the environmental impact of storing spent fuel beyond the licensed operating life of reactors over three timeframes: 60 years (short-term), 100 years after the short-term scenario and indefinitely, August 26, 2014. [assuming 40 year license: 60+40 = 100 (short term)]
SanOnofreSafety.org 51
SanOnofreSafety.org 52 Sandia Labs: Ductile cast iron performs in an exemplary manner Safe from brittle fracture in transport studies cited show DI [ductile iron] has sufficient fracture toughness to produce a containment boundary for radioactive material transport packagings that will be safe from brittle fracture.
Exceeds drop test standards studies indicate that even with drop tests exceeding the severity of those specified in 1 OCFR7 1 the DI packagings perform in an exemplary manner.
Exceeds low temperature requirements Low temperature brittle fracture not an issue. The DCI casks were tested at -29°C and -49°C exceeding NRC requirements.
Conclusions shared by ASTM, ASME, and IAEA
Fracture Mechanics Based Design for Radioactive Material Transport Packagings Historical Review, Sandia Labs, SAND98-0764 UC-804, April 1998 http://www.osti.gov/scitech/servlets/purl/654001
SanOnofreSafety.org 53 Fukushima thick casks
SanOnofreSafety.org 54 Thin canisters not designed to be replaced Welded lid not designed to be removed Lid must be unwelded under water Fuel transfer from damaged canister to new canister must be done under water No spent fuel has ever been reloaded into another thin canister Thick casks are designed to remove and reload fuel Potential problem unloading fuel from a dry storage canister or cask into a pool with existing fuel
SanOnofreSafety.org 55 No defense in depth in thin canisters No protection from gamma or neutron radiation in thin canister Unsealed concrete overpack/cask required for gamma & neutrons No other type of radiation protection if thin canister leaks Thick steel overpack transfer cask required to transfer from pool Thick steel overpack transport cask required for transport High burnup fuel (HBF) (>45 GWd/MTU)
Burns longer in the reactor, making utilities more money Over twice as radioactive and over twice as hot Damages protective Zirconium fuel cladding even after dry storage Unstable and unpredictable in storage and transport Limited technology to examine fuel assemblies for damage Damaged fuel cans vented so no radiation protection Allows retrievability of fuel assembly into another container
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Donna Gilmore SanOnofreSafety.org donnagilmore@gmail.com