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74 C.J. WOOD cn ,< _1 O a u. O cn z 2 .J 30 25 20 15 S 0 10000 8000 6000 4000 2000 PWR 1 PWR 2 PWR 3 DECON OPTION PWR 4 ImmW1 ~IFjtltl ~ C~P@WI. 14BAO IRIIJ. 8~'111rIM lq.Ul RJm. Rjt~ IpffnIM NO IRIIB. 411 im#Ri WIWI I111AM ~ RIIJM.JtCm~NI' Fig. 19. PNR cost-beneflt enalysls: CAN-DECON process PWR 1 PWR 2 PWR 3 DECON OPTION PWR 4 Fig. 20. Estimated cost of each rem avoided ~ decon: CAN-DECON process [] COST D SAVING Im NET BENEFIT [] REM COST
50- 40. 30, 20 ¸ 10 ¸ Chemical decontamination technology' 75 COST SAVING NET BENEFIT BWR FULL SYSTEM(FUELREMOVED) CAN-DECONPROCESS Fig. 21. Example of minimum, best estimate and maximum best cases 9. FUTURE DECONTAMINATION STRATEGIES FOR NUCLEAR PLANTS [] MI~MUM [] BEST EST. MAXIMUM 9.1 Current status Conservative utility estimates show man-rem savings equivalent to the total annual exposure of all U.S. nuclear power plants have been achieved from chemical decontaminations. Even so, only about six plants per year are currently using the technology. The main reason for the relative unpopularity of decontamination at the present time is that fever major repairs of BWR recirculatlon systems are taking place, and steam generator repairs are less common than five years ago. There is no doubt that many utilities still regard chemical decontamination as a major, expensive, tlme-consumlng exercise which is to be avoided whenever possible. Early applicatlons were indeed fraught with problems, critical path delays, corrosion concerns and waste handling dtfflcultles. In almost every case the desired reduction in fields was achieved, but sometimes only after additional steps were taken, such as hydrolaslng. One purpose of this review is to document the maturing of the technology to the point where it Is a tellable option for outage planners to consider. It is now possible to accurately predict the costs and the benefits for plant specific applications. Several utilities who have carried out more than one decontamination, have demonstrated the typical "learning curve" of increasing efficiency at each appllcation. 9.2 Future development Effective chemical reagents are conunerctally available for most appllcatlons and dramatic advances are not anticipated. Some developments concerning the oxidizing processes Involve concerns about corrosion and partlculate residues, but the main technical development will probably be in the area of waste processing. Several methods are under development with the objective of reducing the volume of waste and avoiding current resin
Page 1 and 2: Prt~res.~ io .'~uclear Energy. Vol.
Page 3 and 4: Chemical decontamination technology
Page 5 and 6: ,4. O~¢I~NTAMiNATION Oi I Mfql SYS
Page 7 and 8: Chemical de¢ontaminamm technology
Page 17 and 18: 1.000E-06 1.000E-O7 1.000E-08 Chemi
Page 19 and 20: Types of corrosion testing of decon
Page 23 and 24: Chcmic~tl dccontuminution tcchnolo~
Page 29 and 30: Chemical dccontamim~tion technology
Page 35 and 36: Chcmic~l decontamination technology
Page 37 and 38: (n iz 3 -I o ¢3 It. o (n z o u -I
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