NS&E 618 Treatment of LLW Class 3 - Regulations - PowerPoint by 26s66gVB

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									Class 2
     Review last week’s presentation
     Review activity
     Complete 8/29 slides
     Origin of waste
     Regulations
     Homework


9/17/2012          NS&E 618 -- GAB     1
Radioactivity–Activity–Curies
     Definition of a Curie: the activity of 1
     gram of radium.
     Radionuclides were found to have a
     decay rate proportional to the number,
     N, of radionuclides, or
     dN/dt = -λN (minus sign for decay, λ is
     the proportionality constant)
     dN/N = -λdt

9/17/2012          NS&E 618 -- GAB          2
Solution to Activity
     Integrate last equation
     ln(N) = -λt
     N = Noe-λt
     Solve for λ, by choosing a time when
     the initial population, No, has decreased
     to half
     N = 0.5No = Noe-λt(1/2), take logarithm,
     ln(0.5) = -λt1/2
9/17/2012           NS&E 618 -- GAB          3
Activity Solution Continued
     Therefore, λ = -ln(0.50)/t1/2 = -(-0.693)/t1/2
     λ = 0.693/t1/2
     Therefore
     N = Noe-0.693t/t(1/2)
     Note: This is only true for the number of atoms, it is
     not true for grams or mass. If you know the mass in
     grams, you must first change to N
     N = (6.023E23)*(mass in grams)/(Atomic mass)
     Where the second term is the number of moles


9/17/2012               NS&E 618 -- GAB                  4
Activity Units
     Finally, recall that the activity is
     Activity = -dN/dt = λN = 0.693N/t1/2
     t, time, is in seconds, 1 y = 3.15E7 s
     The above will give activity in
     transitions per sec which is definition of
     Becquerel or Bq
     1 Curie (from 1 g of Ra) = 3.7E10 Bq

9/17/2012           NS&E 618 -- GAB           5
Observations on Activity
     Note that typical masses of
     radionuclides in LLW are pico to micro
     grams
     Typical half life is 30 years or 1E9 s
     Typical activities
      ~ 6E23*1E-9 moles/(1E9 s *3.3E10) =
     microCuries

9/17/2012         NS&E 618 -- GAB         6
Alternate method of
estimating Activity
     Work from old definition, 1 g Ra => 1 Ci
     The mathematical solution states that Activity is
     inversely proportional to half life
     At. mass of Ra-226, t1/2 = 1600 y
     If I had 1 g of Sr-90, t1/2 = 30 y, then
     Activity(1 g of Sr-90) = (226/90)*(1600/30) =134
     (compared to IDB value of 136.4)
     Note: 1st term says lower At. mass, the more
     atoms/g, and 2nd term says shorter half life, the
     higher the activity.

9/17/2012               NS&E 618 -- GAB                  7
Return to Slide 16 Class 8/28
     Helpful hint:
     Remember this chart?
     http://nucleardata.nuclear.lu.se/nuclear
     data/toi/pdf/chart.pdf
     The correct way to read it is to save to
     your disk, open in Acrobat, and zoom in


9/17/2012          NS&E 618 -- GAB          8
1 Ci of 1 MeV Gamma
= 1 R at 1 m
   It’s really applicable to 2 Ci, not 1 but its close enough
   Applicable to gamma that is not appreciably absorbed
   Follows 1/r2 law for point source because gamma’s are
   randomly generated and equal numbers must pass through
   concentric spheres.
   For a line source (pipe) it follows 1/r (concentric cylinders)
   For plane source (floor or wall) it is 1/r0 or independent of
   distance (until air absorption takes over)
   If you measure outside a drum, it can be treated as a point
   source if it is relatively uniform or you are far away (1 m)
   If you look down a pipe through concrete, into a contaminated
   liquid, the point source you see is all the radionuclides in a
   volume through which the radiation can penetrate and you can
   see. Penetration distance for 1 MeV ~ 1 foot


9/17/2012                  NS&E 618 -- GAB                          9
Geometry
     Point source
     1/r2

     Line source
     1/r1

     Plane source
      1/r0

9/17/2012           NS&E 618 -- GAB   10
Origin of the Waste
     Reactor operation, fuel storage, and reprocessing
     Fuel rods occasionally fail (rupture or develop pin
     holes)
     Activated components corrode
     Water coolant becomes contaminated
     Reactors are decontaminated; the process aims to
     dissolve extremely insoluble oxides and metals;
     therefore, the solvents pose a serious solubility
     problem
     Water clean-up systems result in difficult to handle
     resins and sludges.

9/17/2012               NS&E 618 -- GAB                     11
                     Typical LWR Commercial
                     Fuel Bundle. Probably a
                     14x14 in array weighing
                     around 1000 lbs
                     Stainless steel or zircaloy
                     tubes, 0.5 in. diameter,
                     contains uranium oxide
                     fuel.
                     Naval, production, gas-
                     cooled, sodium cooled, and
                     research reactors differ
                     significantly.

9/17/2012   NS&E 618 -- GAB                        12
High Level Waste
     Includes Spent Fuel, first cycle raffinate
     (FCR), and solids derived from FCR
     Transuranic Wastes include in this course, but
     mostly it is in the HLW course
     FCR derived from fuel reprocessing
     Subsequent handling and processing of HLW
     results in LLW. The associated hazardous
     chemicals make it MLLW.


9/17/2012            NS&E 618 -- GAB            13
Fuel Reprocessing
     Dissolve clad fuel, (dissolve fuel and
     cladding or declad and dissolve fuel
     only)
     Extract U, Pu, or both, or FP only
     Fuel is measured in terms of MTHM and
     MWd (burn-up)
     Observe concentrations

9/17/2012         NS&E 618 -- GAB        14
Pu Concentrations of Fuel
     Depends on reactor
     Commercial Reactors use 3.5 to 5 wt.% U-
     235 enriched fuel
     If you remove the fuel at 1% U-235, then Pu
     may be around 2-3 wt.%
     If you extract 99.5% of the Pu, you have
     0.01% left in the waste
     0.01% = 100 ppm -- TRU lower limit 2 ppm

9/17/2012           NS&E 618 -- GAB           15
Other Sources
     Medical radioisotope production and use
     Space applications
     Industrial applications of radionuclides
     Research applications
     Weapons



9/17/2012          NS&E 618 -- GAB         16
10 CFR 20; 10 CFR 60; 10 CFR
61
     These Regulations tell when, what and
     how well to Treat
     These Regulations do not tell how to
     treat, but the requirements for disposal.
     We treat to meet the requirements for
     disposal.



9/17/2012          NS&E 618 -- GAB          17
         Waste Management Regulations
• 10 CFR 20.2001 through 2005 in essence defines radioactive
  waste by what you can do with Radioactive Material:
             Keep
     –      Transfer
     –      Decay
     –      Vent - if less than Table 2 of appendix B
     –      Flush - if less than Table 3 of appendix B
     –      Incinerate
     –      Environmentally Safe 40 CRF 190
     –      Dispose of per 10 CFR 60, or
     –      Dispose of per 10 CFR 61

All are required for HLW treatment
In DOE, we must also include WIPP WAC

9/17/2012                         NS&E 618 -- GAB        18
 Alternatives
 Requiring                              Vent
 Treatment
                   Incinerate



     Radioactive             Operation
     Material                •Use                 Transfer
                             •Process
                             •Store



  Treat
                   Flush                 Dispose of

9/17/2012            NS&E 618 -- GAB                         19
             10 CFR 20 Appendix B

   •   Use for effluents
   •   Note only low allowable concentrations
   •   10E-8 to 10E-7 micro Ci/ml in air.
   •   Appreciate that it is Safety Based
   •   Human Safety takes precedence over Table
       2 – 3 values

   10 CFR 20 is primarily applicable to
   the effluent streams, not disposal streams.
9/17/2012              NS&E 618 -- GAB           20
            Waste Disposal Regulations


• 10 CFR 60
      High Level Waste NS&E 619
• 10 CFR 61
      Low Level Radioactive Waste - scope of this class
• Also not included in class is UMTRAP, FUSRAP,
  and NARM
•UMTRAP -Uranium mill tailings remedial action program
•FUSRAP – Formerly Utilized Sites Remedial Action Program
•NARM - Naturally Occurring and Accelerator-Produced Wastes



9/17/2012                   NS&E 618 -- GAB                   21
10CFR 61.56 - General Waste Characteristics

   • No cardboard containers
   • No free liquid (< 1%)
   • No explosives
   • No toxic or pressurized (1.5 atm) gas
   • No pyrophorics
   • Minimum hazardous, pathogenic and infectious



9/17/2012             NS&E 618 -- GAB               22
            10 CFR 61 General Requirements
    • License based on human health and safety (10 CFR 61.23)

    • Performance Objectives (10 CFR 61.41-44)
       – 25 mRem whole body dose or individual organ
       – 75 mRem thyroid
       – Protect inadvertent intruder (waste form)
       – Long term site stability after closure
           (waste form, no voids)

    • Control Based on Waste Classes A, B, C
    • If Greater Than Class C one should technically
           go to 10 CFR 60, However, this is actually a
           politically sensitive issue)

9/17/2012                 NS&E 618 -- GAB                 23
    10 CFR 61.56 - Specific Characteristics
             (allocable to waste or container)



 • Stability against slumping, collapse, or failure
    of the unit
 • Stability against moisture, microbes, radiation
 • <1% liquid in container; or <0.5% in stable waste
 • Minimum void volume




9/17/2012               NS&E 618 -- GAB               24
The Problem
     Transuranics (Np, Pu, Am, Cm) and
     Actinides (Ac, Th, Pa, U plus TRU)
     Long-lived beta/gamma emitters
     Ultimately dominated by Actinides:
     Am(241 and 243), Pu(239 and 240),
     and Np-237
     and, Fission and Activation products I-
     129, Tc-99, C-14, Nb-94

9/17/2012          NS&E 618 -- GAB         25
The Problem, cont.
     First 1000 years, HLW has both high
     Radiation and Thermal
     Radiation is high enough to cause
     material damage
     Thermal is high enough to raise
     temperatures to 700 - 800 C
     After 1000 yr, HLW equivalent to TRU

9/17/2012         NS&E 618 -- GAB           26
The Solution, HLW
     Deep Geologic Disposal
     10,000 -100,000 year confinement
     Allocate first 1000 years to waste
     container
     Next 10,000 years to Waste Form
     Next 100,000 years to Geologic Media


9/17/2012         NS&E 618 -- GAB           27
The Solution, LLW
     Near Surface Disposal
     100 year institutional control
     300 year waste form




9/17/2012           NS&E 618 -- GAB   28
            Geologically Stable Materials


     NaCl              S
     C                 Clays
     Granites          Basalts (Glasses) Tuft
     Shale, Schist
     Phosphates                  Carbonates




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            Stable Man-Made Materials



                • Glass
                • Bricks
                • Hydraulic Cements




9/17/2012             NS&E 618 -- GAB   30
            Compare 10 CFR 61 Waste
              Characteristics with:


              • 10 CFR 60 (HLW)
                and
              • WIPP WAC




9/17/2012           NS&E 618 -- GAB   31

								
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