1. Sung, Ki-Bang Reduction Method of Spent Resin Generated from
SG BD  Ion Exchangers of PWR NPPS
SEP. 12, 2007
Sung, Ki-Bang

2. Contents 1. Introduction
2. Review of the early SGBD IX Replace Criteria
3. Experiment of IX Resin Capacity
4. Review of Experimental Results
5. Conclusions

3. KHNP’s R&D Institute (1)

4. KHNP’s R&D Institute (2)

5. KHNP’s R&D Institute (3)

6. 1. Introduction (1) ○ Background
In Project of Kori #3,4 NPP PSR,
Main system of LLW Resin : SG BD Demineralizer
Cause : Secondary Side water pH control agent : NH3 ⇒ ETA-AVT
The SGBD cation loads was increased about 2~3 times
Spent Resin Radwaste : Large volume and no Industrial waste…
Not easy to treat the ash, though spent resin is almost disposal object itself
PSR Team treated as safety issue item
PSR Team(NETEC) and Kori 2 Chemistry Section agreed to the problems and solved the sophisticated problems

7. Block the leaked Activities Recovery BD Bleed water
1. Introduction (2)
SG BD system’ functions
Block the leaked Activities
Recovery Heat
Capacity : 5000ℓ×2ea Design flow : 45ℓ/sec Normal flow : 45ℓ/sec
Recovery BD Bleed water

8. 1. Introduction (3) 15.4ton/Yr (65%) Spent IX Resin Source SG BD Demin
SFP IX
2.0ton (9.4%)
CVCS IX
3.3ton (18.9%)
15.4ton/Yr (65%)
SG BD Demin
LRW System IX 1.7ton (7.1%)
22.4 ton/Yr
2.12 t
3.71 t
7.95 t

9. 1. Introduction (4) Ion Exchange Resin ? Model of Ix Resin
Bead of amorphous and sphere type high polymers
100billions IX sites / bead
IX Mechanism

10. 2. Review of the early SGBD IX Replace Criteria (1)
In Domestic Plants,
 IX Resin Replacement Procedures of SGBD IX
- No standard Criteria of SGBD IX
- Na was a typical ion to determine the IX removal capacity in many plants.
- However, Na was not a typical ion to determine IX removal capacity other plants ( See the next page table )
In USA NPPs, (from EPRI report)
 IX Resin Replacing Procedures of SGBD IX
- 22 of 73 PWR plant didn’t consider the Na ion as IX replacement Criteria

11. 2. Review of the early SGBD IX Replace Criteria (2)
Table : IX Exchanger Replacement Criteria of Domestic Plants
Criteria
Plnat
IX Replacing Criteria
note
Operation Demin.
After Demin.
A Plant
Na+ ≥ 5ppb
C.C ≥0.5 μS/㎝
Na, Cl-, SO4-2 ≥ 2 ppb
B Plant
Na+. DF ≤1
Na+. Cl-, C.C  DF ≤1
DF = Inlet Conc.
      Outlet Conc.
C Plant
SO4-2 DF ≤1
D Plant
C.C increase or Na+≥2ppb
C.C≥0.2 μS/㎝
Na+, Cl-, SO4-2 ≥ 2ppb
E Plant
C.C≥0.5μS/㎝ 
Na+, Cl-, SO4-2 ≥ 2 ppb NA
1 Operation,
1 Stand-by
F Plant
C.C≥0.1μS/㎝ “
G Plant
Na+≥3 ppb Cl-, SO4-2≥5ppb

12. 3. Experiment of IX Resin Capacity (1)
Scheme and Shots

13. 3. Experiment of IX Resin Capacity (2)
Ion selectivity experiment with H-type IX resin
ETA
NH4 Na Cs
Volume Flow

14. 3. Experiment of IX Resin Capacity (3)
ETA, NH4, Na Ion selectivity experiment with Cs-type IX resin
ETA Na
NH4 Cs

15. Same characteristics of new IX Resin
4. Review of Experimental Results (1)
NH4 Na
ETA Cs
Saturated IX Resin
Same characteristics of new IX Resin
ETA
NH4 Na Cs

16. 4. Review of Experimental Results (2)
Ion Absorbing Capacity on Resin
Experiment : 1/80000 of 2.5 ㎥ which was equal to 30㎖ of resin capacity
and experiment was achieved for resin which is 30 times of addicted chemical material
  Experimental result (ion selectivity on resin) : H+  <  NH4 + ≤  ETA+ <  Na+  < Cs+  
Ion
molecular
weight
ion concentration
system
concentration
(ppm)
ratio with
system ion
(ppm) 
   (meq/l)
ETA+
61.08
122.16 2
3.5 35
NH3+ 17 34
0.2
170
Na+ 23 46
0.001
46000
Cs+
133
266 ∞
total
101.08
202.16 8
3.701 - 

17. 4. Review of Experimental Results (3)
Ion Breakthrough Curve Characteristics
  ETA
      0.5 [Output conc./Input conc.] Breakthrough time(T) ->     
(ETA+NH3) : Na : Cs = 2T : 3T : 4T
    This phenomenon came from ETA/NH3, Na and Cs ‘s different selectiveness.
  NH3
        NH3 was eluted after ETA and exchange reaction was faster than ETA.    ※ NH3 was produced from ETA or N2H4 which removes Oxygen.
  Na
     Na’s sensitivity was stronger than NH3 or ETA. So, Na was eluted after NH3 or ETA.
  High Peak position of Na Conc. was overrode on Cs’s conc. 1.0 meq/ℓ(half input Conc.)
⇒  Cs extrude Na
  Cs
     Cs has S-shape breakthrough characteristics like single ion and it was absorbed on IX resin.
Cs was not affected by other ions, and Its behavior look like single ion solution.

18. 4. Review of Experimental Results (4)
The resin replacement criteria of cation resin
  - ETA was not impurity in system, and should not be removed at deminerlizer (On the contrary it should be circulated)
  - The small Na leakage from new resins was not controlled and excluded at demineralizer exchange criteria.
  - Even impurities by outside influx was suddenly increased, the impurities concentration should be decreased in proportion to circulating volume as time passes. Impurities, concentration should be decreased.
    Table. The SG blowdown water quality of PWR
Operation
Operation mode
Na criteria
(ppb)
Cl criteria
Startup
operation
reload→ cold standby (mode 6-5)
≤ 100
hot shutdown (mode 4)
hot standby (mode 3)
startup operation (mode 2)
Reactor power
reactor power (5~30%)
reactor power ( 30%)
≤ 20

19. 4. Review of Experimental Results (5)
The resin replacement criteria of IX resin
Na concentration should be less than 100ppb at maximum or stop operation.
If the limited concentration at the second step is less than Na 100ppb,
the concentration at Na DF 10 should be 10ppb.
DF 10 of Na Spec value (20ppb) is 2ppb, and Max conc. of Na is 3ppb
at operation over 30% generation. Therefore sum of them is less than 5ppb.   
The water quality level is less than Na concentration(5ppb).
Therefore, improvement of cation resin change criteria is that the Na outlet conc.
is reasonable to be selected less than 5ppb.
Cl , SO4-2 and Conductivity would be derived from system parameters as below.
◆ The resin exchange criteria of SG blowdown demineralizer
-  exchange criteria of mixed bed : [Na, Cl ≥ 5 ppb ] 
-  reference exchange criteria : [SO4-2 ≥ 5 ppb,  C.C ≥ 0.3㎲/㎝ ]

20. 4. Review of Experimental Results (6)
The SGBD Ion Exchanger’s cation/anion mixing ratio
Table : Ion load for water quality of flow water
Item
Ion
Max.conc (ppb)
M.W (g./mol)
Ion load
( x 10-9 eq/ℓ)
Considered ETA, NH4
not considered ETA, NH4
ETA
5,000
61.08
81.86 NA
NH4+
500
17.00
29.41
N2H4 50
32.00
1.56
Na+ 20
23.00
0.87
total
115.05
3.78
Anion
Max organic acid x 1
Max organic acid x 5
Cl-
35.50
0.56
SO4-2
96.06
0.42
SiO2-
100
60.08
1.66
Acetic acid
60.05
0.333
1.67
Glycolic acid
76.05
0.263
1.31
Formic acid
46.02
0.435
2.17
3.67
7.80

21. Calculated Resin Volume capacity
4. Review of Experimental Results (7)
The SGBD Ion Exchanger’s cation/anion mixing ratio
Table.  Calculated Resin Volume with system ion loads
Item
Resin
Ion Load of System
(x10-9 eq/ℓ)
Removal Capacity of Resin *
(eq /ℓ resin)
Calculated Resin Volume capacity
(x 10-9 ℓ resin)
ETA considering
ETA not considering
Cation
115
3.78
1.8
63.9
6.5
Anion
Max organic acid x 1
3.67
1.2
3.1
Max organic acid x 5
7.80
2.1
◆ SG BD demineralizer’s cation/anion resin mixing ratio
  - the ratio of cation and anion resin was 10 : 1 considered ETA load
   - the ratio of cation and anion  resin was 1 : 3 excluded ETA load
   - The Mixing ratio of Resin (margin : ETA elution effects) 3 : 1

22. 5. Conclusions (1)
Saturated IX with ETA Capture the Na and Cs ion
Satisfaction of PWR FSAR’s Requirements
Confirm the cation IX Resin Selectivity in ETA solution
Cs+ > Na+ >  ETA+ ≥ NH4+ > H+
Verify the Cs ion Selectivity of H-, ETA-saturated IX
No load IX Resin for ETA or NH4
Confirm the Na ion Selectivity in ETA solution
Satisfaction of EPRI secondary water Guidelines

23. 2 1 3 4 5. Conclusions (2) Technical Effects
Standardization Spent Resin Criteria and Mixing IX Resin 2
Establish Spent Resin change Criteria 1
Technical Effects
Obtain ion Selectivity for H-type ion 3
Examined Na’s behavior in system 4

24. 5. Conclusions (3) Other Effects Reduce works on Radiation area
Reduce Spent IX resin(370t/yr)
Save the Cost(3.3billionWon/total
Reduce works on Radiation area
Min. Low Level Radioactive Wastes
Min. Radiation Exposure
Other Effects
Water quality treatment tech.
Co-works
Max. removal Capacity of Resin
Solving Problem example with another team

25. Thank you for your attentions !