Recent R&D Activities on Tritium Technologies in Tritium Process Laboratory (TPL) of Japan Atomic Energy Agency (JAEA)

Transcription

1 Recent R&D Activities on Tritium Technologies in Tritium Process Laboratory (TPL) of Japan Atomic Energy Agency (JAEA) Toshihiko Yamanishi, Takumi Hayashi, Yoshinori Kawamura, Hirofumi Nakamura, Iwai Yasunori, Kanetsugu Isobe, Kazuhiro Kobayashi, Takumi Suzuki and Masayuki Yamada Tritium Technology Group, Direactorate of Fusion Research and Development, Japan Atomic Energy Agency Shirakata Shirane 2-4, Tokai, Ibaraki, JAPAN 3rd China-Japan Workshop on the tritium and Breeding blanket technology (CJWS-3), Kunming, China, Jun 20-23,

2 1. Operation of TPL(Tritium Process Laboratory) facility History: Construction of building of TPL = 1984 Construction of safety systems = 1985 Licensing for tritium = 1987 Operation with tritium = 1988 Purchase from US and Canada= Amount of trtium Maximum amount of tritium storage approved= 22.2 PBq (about 60 g), actual value =12 PBq at March of 2009, 4.9 EBq/year = Usage value approved Facility: 14 glove boxes and 22 hoods 2

3 Experimental Apparatus Glove Box Secondary Confinement 0.1 Vol% at 100 mm Aq GPS:Glove box gas Purification System)DF=100 ERS(Effluent Tritium Removal System)DF=10000 Temporary tent House for maintenance Stack Basic concept of tritium Confinement = Multiple comfinement Coceptual flow diagram of tritium removal system = Vessel, Preheater, Catalytic reactor, Cooler, Molecul ar sieve bed ACS (Air Cleanup System)DF=100 From experimental apparatus Vessel DRS(Dryer Bed Regeneration System) Waste water Vessel Experimenta l room Tertiary Confinement 1Vol% at 15 mm Aq From glove box Cooler Catalysts 473 K and 773 K Molecular sieve bed To stack Compressor Pre-heater Recycle operatio n 3

4 Amount of tritium released (GBq) HT 40 HTO Fiscal year Amount of tritium released from stack = 3.6x10 11 Bq (HTO), 3.0x10 10 Bq(HT), Average concentration of tritium at stack = 60 Bq/m 3 (1/100 of regulation value). Recently, the amount of tritium released is increased. This is because some apparatus has been disposed and stored in a hood with completion of some R&D subjects. 4

5 2.Recent activities for ITER -Status of ITER-DS (Detritiation System)- Back Ground ITER Tritium Plant = Remove impurities (TEP:US, ISS: EU), supply D and T (SDS: KO, Fueling: CN), Tritium recovery and remove (DS: JA, WSS: EU). The DS (Detritiation System) = key system of tritium confinement The concept of DS of ITER was the same as that of TPL: catalytic reactor and molecular sieve bed. 1. Design change The design of DS has been changed in accordance with the requirement of licensing authority of French. measures for power failure and fire accident, etc The scrubber column has been applied, since there are problems on the reliability of valves of the molecular sieve beds in the regeneration operations. 5

6 HVAC 2.Recent activities for ITER Recent flow diagram of ITER-DS HVAC M1 MSDS MSDS: Catalyst + Molecular sieve bed For maintenace operation Vault HVAC NB cell Tokamak Complex Vacuum vessel Port plug HVAC Gallery Port cell M2 M3 SCDS: Catalyst + Scrubbe column HVAC GDS Tritium system s GB ISS others Tritium plant rooms SCDS SCDS SCDS M4 M5 Release point HVAC SCDS SCDS SCDS 6

7 2.Recent activities for ITER Pilot plant scale test 1.Back ground Scrubber column = Water-water vapor Counter-currently column It has been established in Chemical Engineering; however, there has been no tritium data. 2. Basic experiments by RF 6 cmφx100 cm height, 16 m 3 /h 1/100, Cupper treated packing, HETP:5~9 cm 3. Pilot scale test at TPL 350 m3/h, 1/4, Sulzer packing (similar to that of basic experiments) 30 cmφx 200 cm, The reliability of extrapolation of detritiation to 1000 should 7 be proved.

8 3. Recent Activities for BA program The BA programs were started as the collaborative activities between Japan and EU for fusion DMEO reactors from ) Engineering Design Activities for the International Fusion Materials 2) Satellite Tokamak Program : upgrade of the existing JT-60 facility to an Advanced Superconducting tokamak ; 3) International Fusion Energy Research Center (IFERC): -Fusion Computer simulation, DEMO R&Ds Advanced structural materials (reduced-activation ferriticmartensitic steels and SiCf/SiC composites), Advanced blanket materials (breeders and multipliers); Tritium technology Tokai (JAEA) Rokkasho, Aomori(JAEA) 8 Tokyo 8

9 3. Recent Activities for BA program Continuous operation, control of the loop. Exposed to tritium for a long period Enhance design, safety, and public acceptance for DEMO. 1.2 R&D subjects Task (1) Multi-Purpose RI Handling Equipment (Facility) The tritium usage amounts per day and per year is 3.7 and 1.35 PBq, respectively. The maximum amounts of tritium per Hood and for storage are 0.37 TBq and 7.4 TBq, respectively. The licensing for other RI is ~1/100 of tritium. Task (2) Tritium Accountancy Technology Development of micro GC, calorimeter, BIXS etc, advanced tritium gas Task monitors (3) Basic and real Tritium time tritium Safety monitor Research for water. Tritium behaviour in advanced materials to be used in DEMO(F82H/SiC/etc., blanket breeder & multipliers, PFCs (SiC/W etc.). Task (4) Tritium Durability Test Endurance tests of fuel cycle components at high tritium exposure (Membrane durability for WDS electrolysis cell). 9

10 3. Recent Activities for BA program Tritium Handling Area Waste liquid vessel Controlled Area Nuclear HVAC 990 mm Electricity & Cold HVAC 30 m x 50 m x 7 m Entrance Cold Rooms And Be Exp. Room 940 mm Glove box and hood Stack : 20 m Glove box atmosphere Detritiation System: 6 m 3 /h Effluent gas Detritiation System: (EDS) 2 m 3 /h mm 1950 mm 10

11 3. Recent Activities for BA program -Preliminary activities on the R&D of tritium technologies- (1) The licensing of the RI facility at Rokkasho will be finished in 2010 as already presented. Hence, the R&D activities with tritium at Rokkasho and at TPL (Tritium Process Laboratory at Tokai site) will be started from (2) To start these studies smoothly, a series of preliminary works has been started with Japanese Universities from late 2009 for Tasks 2 and 3. (3) The works are discussions on experimental setups and procedures and review of past results, and have been started with universities in Japan. Example of collaborative R&D (1) Quantitative tritium measurement with wide dynamic range by using an imaging plate: measurement of tritium in solid: a kind of photo film, the film is exposed by X-ray of tritium (2) Tritium uptake and release behavior of F82H, PFC, and W materials (3) Evaluation of tritium behavior in blanket materials: tritium behavior in liquid blanket material (Li-Pb) 11

12 4. Basic R&D for tritium Tecnology We have carried out the following R&D subject 1)R&D on recovery of tritium from blanket system (water vapor and hydrogen) 2)R&D on advanced hydrophobic catalysts 3)R&D on tritium durability of organic compounds used in electrolysis cell of WDS 4)R&D on interaction between high concentration of tritium water and metals, corrosion, and permeation R&D using caisson (12 m 3 stainless steel box) with Japanese Universities 5)R&D on tritium monitoring for each chemical species of tritium (The concentration limit of tritium in regulation depends on the chemical species of tritium (water, water vapor, hydrogen, organic compounds). 6)R&D on tritium behavior in concrete The amount of tritium and diffusion coefficient of tritium In concrete are measured. 12

13 1)R&D for Blanket tritium Recovery System - Electrochemical Hydrogen Pump- Schematic of electrochemical hydrogen pump. (SCO: SrCe 0.95 Yb 0.05 O 3- ). Correlation between the proton concentration in SCO and hydrogen pressure in the gas. = nd(ez) 2 /kt D : diffusion coefficient, e : elementary charge, k : Boltzmann constant, n : ion concentration in ion conductor, T : temperature, Z : valence number, : ion conductivity (Dry ) n = 3.0 x P 1/6 (Wet) n = 6.4 x P 1/16 Partial pressures of hydrogen and water vapor control the proton concentration in the ceramic as a key parameter of the system. 13

14 Ion Exchange Capacity 10 4 [mol-oh - /g-dry Nafion] Elongation at break [%] 3)R&D on tritium durability of organic compounds used in electrolysis cell of WDS Solid-Polymer-Electrolyzer (ITER WDS) Ion excange membrane (NAFION), Two years continuous operation in tritiated water of 9TBq/kg, Corresponding to irradiation of 530kGy Gamma and beta-ray tests were conducted prior to tritium test Deionized Water NaCl Solution Dose [kgy] No serious decrease was observed for the performance of Nafion membrane for the irradiation in distilled water. However, serious effect of ion in water was observed. A series of tritium durability tests for organic compounds has been started by immersing the samples into tritium water Dose [kgy] 14

15 4)R&D on interaction between high concentration of tritium water and metals, corrosion, and permeation How to confine tritium within high temperature breeding blanket is the key issue for safety and fuel economy of the fusion reactor. Tritium permeation experiment into water jacket (0.8MPa by He) was performed through pure iron piping, which contained about 1 kpa of pure tritium gas at 423 K, with monitoring the chemical forms of tritium in water jacket. Typical results oxide layer growth (magnetite, 1.7mm) on iron after 20 h in water jacket at 423K Hydrogen gas (HT) fraction in water jacket decreased drastically with oxide layer growth (magnetite, porous & fine layers), though tritium permeation rate to water was not changed. 15

16 5. Summary 1) At TPL of JAEA, tritium technologies for the fusion reactors have been carried out since 1988 with a gram level of tritium (30-60 g). A series of safe operation of tritium has thus been demonstrated for 22 years with no tritium release accident. 2)As one of the most important activities at TPL, a series of demonstration tests for a pilot plant scale of DS of ITER has also been started at TPL. 3)The R&D subjects have been applied as generic and basic studies under the Broader Approach (BA) program in Japan: 1) tritium analysis technology; 2) basic tritium safety research; and 3) tritium durability test. A multi-purpose RI facility has been designed in detail, and has then been constructed at Rokkasho in Aomori. 4)Some basic studies were carried out for the tritium recovery system for a DEMO reactor blanket, radiation durability of the polymers in the SPE, tritium permeation into a water or water vapor was carried out from viewpoint of safety and tritium production in the blanket area. 16