NSE 618

1. 6/5/2012 NS&E 618 1 NS&E 618 Class 9 Questions regarding the test? Presentation � begin preparation Finish ion exchange from 10-3 lecture Cement Portland Cement Association literature Concrete Uses of cement in waste management Advantages and disadvantages Laboratory mixing test

2. 6/5/2012 NS&E 618 2 Ion Exchange Media is generally in the form of a resin Resin is a generic term for a complex plastic like media, but also includes clays, zeolites, and other minerals with the capability to hold cations or anions at less than chemical bond strengths Ion exchange can also occur with individual complex molecules, the method of choice used in reprocessing

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4. 6/5/2012 NS&E 618 4 Ion Exchange Resins Loading in terms of meq/g Possible loadings up to 10% by weight Use to breakthrough Then discard or strip Discuss advantages and disadvantages

5. 6/5/2012 NS&E 618 5 Ion Exchange High DF Why low capacity? Because sites can be occupied by other ions such as Na, or Ca Since the resins are porous Resulting waste may be 50% water Don�t burn well, (water filled plastics) Hard to solidify Disposal in High Integrity Containers (HICs)

6. 6/5/2012 NS&E 618 6 Operational Concerns with Liquid Waste Treatment Transition from liquid to solid Handling solids Waste form gets harder and harder to handle Clean out Recovery from upset Monitoring

7. 6/5/2012 NS&E 618 7 Decontamination Factors Most decontamination factors range from 1 to 10,000

8. 6/5/2012 NS&E 618 8 Portland Cement Portland Cement Association literature Go to their homepage and browse http://www.portcement.org/cb/ Text book, Section 6.2 Concrete is rocks, sand, cement, water Cement and water is �grout� although the term varies widely with users Mortar is cement, sand, and water

9. 6/5/2012 NS&E 618 9 What is Portland Cement Complex mixture of compound oxides Sets by incorporating water of hydration and calcium hydroxide into a crystalline matrix Has been used for at least 2000 y in varying compositions Heating most soils and limestone will produce a cementitious material Relatively insensitive to mixtures of Ca, Si, Al, and Fe oxides

10. 6/5/2012 NS&E 618 10 Portland Cement Composition and Hydration C3S = 2(3CaO � SiO2) +6H2O ? 3CaO � 2SiO2 � 3H2O + 3Ca(OH)2 C2S = 2(2CaO � SiO2) + 4H2O ? 3CaO � 2 SiO2 � 3H2O +Ca(OH)2 C3A = 3CaO � Al2O3 + 12H2O +Ca(OH)2 ? 3CaO � Al2O3 � Ca(OH)2 � 12H2O also C3A = 3CaO � Al2O3 + 6H2O ? 3CaO � Al2O3 � 6H2O C4AF = 4CaO� Al2O3 � Fe2O3 +10H2O + 2Ca(OH)2 ? 6CaO � Al2O3 � Fe2O3 � 12H2O C3A = 3CaO � Al2O3 + 10H2O + CaSO4 � H2O ? CaSO4 � 3CaO � Al2O3 � 12H2O In line 3, ? mol wt = 540; wt of H2O = 196; ratio = 0.36, I.e., 36 wt% H2O (see xls spread sheet)

11. 6/5/2012 NS&E 618 11 Observations Heavy dot, � , indicates molecule to molecule bond, intermediate to a atom-atom chemical bond. Note that heats of hydration = 100 � 200 cal/g, versus chemical bonds of water = 68 kcal/mole or 68/18/2 =~2000 cal/g In Portland cement jargon, C is Calcium (oxide) and S is Silicate (dioxide), and A is aluminate and F is Ferrite This is clearly outside the normal chemical world, but i.e., C2S is Di (two) Calcium silicate C3S is Tri (three) Calcium silicate C3A is Tri (three) Calcium aluminate C4AF is Tetra (four) Calcium aluminoferrite

12. 6/5/2012 NS&E 618 12 Properties See the xls spread sheet

13. 6/5/2012 NS&E 618 13 The 5-bag concrete Portland cement has traditionally been sold in 94 lb. bags. 94 lbs - 1 cubic foot Concrete is sold in cubic yards Randomly packed solids are about 40% by volume void. (See p. 369) Therefore, 1 yd of rock has 12 cu ft of void Fill the void with sand 12 cu ft of sand has 5 cu ft of void Fill the void with cement 5 cu ft of cement has 2 cu ft of void Fill the void with water (actually, it requires 3 cu ft of water) Note: Today�s standard construction-grade concrete is 6-bag/yd

14. 6/5/2012 NS&E 618 14 General Application of Cement Tie up water as a stable solid Neutralize mild acidic waste Form monolithic solid waste forms

15. 6/5/2012 NS&E 618 15 Acceptance Accepted by all commercial radioactive waste burial sites Accepted by regulatory agencies Accepted by Stakeholders: Trusted by the general public (homes, roads, dams, sidewalks) Accepted by international community

16. 6/5/2012 NS&E 618 16 Advantages of Portland Cement Tolerant of wet material Not flammable or combustible Durable in natural environment Low leachability Easily incorporates a wide variety of materials Inexpensive, readily available Easily prepared Extensive infrastructure (sources, equipment, users) Safe (nontoxic) and easy to handle

17. 6/5/2012 NS&E 618 17 More Advantages of Portland Cement Material and technology well known Most aqueous wastes bond to matrix Low cost No vapor (low temperature) Long shelf-life Good impact and compressive strength Known long life

18. 6/5/2012 NS&E 618 18 More Advantages of Portland Cement Compatible with a wide variety of wastes and substances Rocks, minerals, clays, pozzolans, glass Fly ash and blast furnace slag Metals, steels, copper Asphalt Aqueous organics Some polymers

19. 6/5/2012 NS&E 618 19 More Advantages of Portland Cement Satisfies 10CFR61 prohibition of pyrophoric materials Generally can satisfy 10CFR61 prohibition > 1% free liquids Minimizes void volume Generally can satisfy the 10CFR61 requirements for stability Generally can satisfy the 10CFR61 prohibition of explosives Generally can satisfy the 10CFR61 prohibition of cardboard containers Generally can satisfy the TCLP leach rate requirements

20. 6/5/2012 NS&E 618 20 More Advantages of Portland Cement Material and technology well known Most aqueous wastes bond to matrix Low cost No vapor (low temperature) Long shelf-life Good impact and compressive strength Known long life

21. 6/5/2012 NS&E 618 21 Portland Cement Association Literature Types of source material Types of Cement Role of sulfate Ettringite formation Where is the waste? Amphoteric metal ions Effects of various metals and organics

22. 6/5/2012 NS&E 618 22 Chemical Compatibility w/Hydraulic Cements

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24. 6/5/2012 NS&E 618 24 Disadvantages of Portland Cement Dust problems Equipment messy and difficult to maintain Difficult to recover from failed product Many of the hazardous wastes are incompatible with PC Specifically metals - Pb, Hg, Cd Generally incompatible with sodium salts Organics � generally incompatible with: Oils, petroleum products Plastics, resins Fluorinated and chlorinated hydrocarbons

25. 6/5/2012 NS&E 618 25 Cement Advantages and Disadvantages See ORNL-13224, September 1997 Clearly advantages, but clearly disadvantages Disadvantages lead to NRC Technical Position on Waste Form

26. 6/5/2012 NS&E 618 26 NRC Technical Position on Waste Form Requirement is Stability -- All B-C wastes, including PC Solid or in a container or structure that provides stability No (0.5 wt.%) free standing and corrosive liquids Waste or container resistant to radiation Resistant to biodegradation Stable under site compressive load Stable to moisture or water Waste compatible with solidification medium or container

27. 6/5/2012 NS&E 618 27 Stability Criteria for Portland Cement (From the NRC Branch Technical Position Paper #1) Compressive strength max practical > 500 psi Survive 30 thermal cycles -40 to +60 C centerline temperature then compressive test Remain stable after 1E9 rad, if required, else no testing required Biodegradation tests not required if no food (carbon or sulfur); if so, there must be no significant cracking Leachability index > 6 in the harsher of de-ionized or sea water 5 day test is adequate Survive 90 day immersion after which compressive strength must be > 0.75 initial strength Free liquid pH > 9 Demonstrate that test samples represent full scale Full scale specimens must be homogenous Tests must occur after reaching > 75% peak strength

28. 6/5/2012 NS&E 618 28 Uses of Cement Evaporator Bottoms, Resins, Filter sludges SRP and WVDP use portland cement based solidification systems for the final treatment of their LLW nitrate-sludge fraction of the neutralized HLW (whereas the HLW is vitrified.) The product is known as Saltstone

29. 6/5/2012 NS&E 618 29 More Uses of Cement Hanford developed and initiated use of a major portland cement based system for liquid LLW decontamination wastes -- Million gallon monoliths INEEL recently used portland cement grout to backfill underground vaults ORNL cemented 20 Mgal of liquid wastes Principal treatment alternative of AMWTF

30. 6/5/2012 NS&E 618 30 More Uses of Cement Small mostly liquid waste streams are most economically cemented Incinerator ashes Misc. debris Sr based wastes Improved transportation durability

31. 6/5/2012 NS&E 618 31 Examples WCF RCRA Enclosure Fill large vaults (Buildings - Basements) void free, instead of removing Issues: Heat, flowability, set time, ultimate strength Centre de la Manche and de l�Aube Komar

32. 6/5/2012 NS&E 618 32 Waste Form (Guidance) Requirements 0.5 wt.% free liquid as per ANS 55.1 60 psi as per ASTM C39 or ASTM D1074 (Bitumen) 30 thermal cycles -40?C and +60?C 1E8 Rad Bio resistant as per ASTM G22 Leachability index >6 as per ANS 16.1 Free liquids 11 > pH > 4 Demonstrate on Full Scale specimen. Plus a PCP that demonstrates your process

33. 6/5/2012 NS&E 618 33 Other Solidification Matrices Bitumen Polyethylene Polyesters, Polyurethane, Epoxy Sulfur polymer Phosphate bonded ceramics Zeolites Metals

34. 6/5/2012 NS&E 618 34 Stabilization Notes These are slides Asphalt, known to the rest of the world as Bitumen.

35. 6/5/2012 NS&E 618 35 Asphalt (Bitumen) Asphaltenes and Aromatics C - 84% H - 10% S - 4% Types Distilled Blown Emulsified

36. 6/5/2012 NS&E 618 36 Bitumen Waste Form Characteristics Radiation tolerance to 2E8 rad (p. 19) Leach rates 1E-6 g*cm-2/d (p.22) [1 cm cube would last 105 days] Flash point of Bitumen-NaNO3 220-260 C (p.33) Waste forms and leach rates (p. 50, 51, 78)

37. 6/5/2012 NS&E 618 37 Facility Experience Example facilities (p. 26-93) Operational parameters (p. 62-93) Two fires - France in 1970-72 Japan in 1997

38. 6/5/2012 NS&E 618 38 Laboratory Mixing Weigh out 150 g of portland cement Select some sand Calculate amount of H2O required add 90% Now add enough H2O for 200 g of portland cement Now add the other 50 g portland cement Estimate the excess water to add; add it