Development of tritium breeder monitoring for Lead-Lithium cooled ceramic breeder (LLCB) module of ITER presented V.K. Kapyshev CBBI-16 Portland, Oregon, September, 2011 Portland, Oregon, September, 2011

OUTLINE 1. Problem of Tritium Breeding Ratio (TBR) monitoring 2. Fusion Reactor Facility for Tritium Breeder Monitoring 3. R&D

Tritium Breeding Ratio (TBR) of DEMO / ITER The most important tritium cycle parameters : - tritium breeding ratio (TBR), - amount of tritium in the reactor, ТВR = Q reactor / Q plasma (1) Q reactor – tritium amount breaded in reactor blanket and plasma Q plasma - tritium amount burned-up in plasma. Q reactor = Q TBZ +Q DD

Conception of TBR monitoring using Test Breeding Modules of ITER Conception of TBR monitoring of reactor includes: - measurements of numerator and denominator in formula (1), - calculation booth. Experimental definition of tritium amount burned in plasma (denominator in formula (1)) is proposed to do by measurement of neutron number arisen in result of (D-T) reaction. Numerator demonstrates tritium breeder in a tritium breeder zone (TBZ) of reactor blanket under neutron interaction with lithium and beryllium isotopes

Problem of TBR Precision Measurement TBR for the DEMO with ceramic blanket ~1.05. Error ( Δ ) of TBR measurement according (1): Δтв R = Δrеакtоr + Δplаsmа Δrеакtоr ~Δ TBZ The most accuracy measurements can be done in case of tritium breeder and neutron detectors location in TBZ for short time and follow remove of its from TBZ after plasma pulse, delivery to an analytical laboratory for analyzing. Q reactor

Fig. 1 Conception of TBR monitoring using TBM of ITER 1- TBZ of TBM, 2- Tritium Breeding Canals (TBC) for samples, 3- casks with samples under irradiation, 4-in-put chamber, 5- transporter room, 6- tritium laboratory delivery of casks with samples; extraction of irradiated casks

Fig. 2. Location of capsules with material samples in cask This is a capsule presenting hermetic cylinder cask closed by plugs to each end.

Table 1. Content of samples in casks № cask Tritium breeder material Isotope ratio ( 6 Li / 7 Li) Absorbers of thermal neutrons 1Li 2 CO 3 natural– 2Li 4 SiO 4 natural+ 3Li 4 SiO 4 natural– 4Li 4 SiO 4 ~ 1– 5Li 4 SiO 4 ~ 1+ 6Li 4 SiO 4 ~ 10– “+” –yes, “-“- no

2. Pneumatic and mechanical systems of transportation the casks to the Module The canal (TBC) contains three parts: - “operation” part with length ~ 0.55 m locating in TBM; - part between TBM back plate and operation room; - “leader” part with length ~ 0.5m for loading and unloading casks. Transportation of the cask to the Module and back is proposed to do by two methods: mechanical with gas cooling and pneumatic.

2.1 Initial Design of Pneumatic Tritium Breeding Canal (TBC) The canal (TMC) for irradiation materials is thought as two coaxial pipes (Ø 14х1 mm and Ø 20х1 mm). Coolant movement through the canal is possibly both straight and reveres. Fig. 3. Longitudinal section of TBC 1-beryllium plug, 2-container, 3-beryllium multiplier, 4-separation elements, 5-rib of TBSM case, 6-back plate of TBM case, 7-out side of canal pipe, 8-bellow, 9-frame, 10-inner pipe of canal, 11-shield plug, 12-armored bellows, 13-heat shield, 14-biological shield, 15- fastening unit of canal,16-union, 17-adapter, 18-load chamber, 19- fingered bushing, 20-bolt, 21-transporter.

Fig. 4 Conceptual diagram of monitoring breeder tritium system with gas circulator to provide necessary temperature mode of lithium detector operation 1-channel of tritium breeder monitoring, 2-commutator of gas flow, 3-system of gas circulator, 4-pneumatic deliver system of samples to channel, 5-monitoring tritium system in CCTB, 6-pressure regulator, 7-gas cylinder, 8-heat exchanger, 9-circulator pump, 10- vacuum pump, 11-tank, 12-system of initial gas process and monitoring of tritium content in the gas, 13-system of radiation safety

TMC Fig.11 Tritium Monitoring Canal in Ceramic-Eutectic TBM L radial =450mm.

Table 4 Tritium breeder in detectors of TMC placed in core of TBM’s cap (t=3*10 3 c) Bk/detector detector Li-6 content _________________________________________________________ 9.24E+04 Eutectic 7.4% 3.62E+06 Eutectic 50% 3.12E+04 Eutectic 90% 2.60E+04 Li 4 Si O 4 7.4% 3.02E+04 Li 2 CO 3 7.4%

R&D 1. Laboratory devices for investigation of pneumatic systems 2. Development: - cask and capsule, - analytical methods for measurement of tritium breaded in lithium detectors under irradiation in IVV-2M nuclear reactor 3. Selection and irradiation of neutron detectors in IVV-2M nuclear reactor 4. Irradiation of the cask and capsule in IVV-2M

Development and test of Tritium Breeding Ratio (TBR) system monitoring -laboratory facility for parameters investigation of sample deliver to TBM (pneumatic method, length=9m, T(active zone) = 200  С) methods and analytical systems for measurement of tritium breaded in the samples (Li 4 SiO 4, Li 2 CO 3, tritium content~10 3 bq/s) -development of nuclear reactor facility for TBR system monitoring test (T=200  С, neutron flux ~ 2*10 14 n/sm 2, t (neutron irradiation)~10min)

Development of liquid scintillation method Li 2 CO 3 Dierckx’s method (1973) Δ Li-sample = 6-7% Li 4 SiO 4 Verzilov’s et all method (2005) Li 4 SiO 4 +4HA=4LiA+SiO 2 ↓+2H 2 O HA=mix(CH 3 COOH; HNO 3 ) Δ Li-sample = 10 %

Hydrogen isotope permeation through structural materials Laboratory facility for investigation of hydrogen permeation through structural materials (T=  С P(H2/D2~0,1 МПа, ferritic SS 10X9MB9,austenitic SS ) Development of reactor experimental facility for investigation of tritium release through structural materials under reactor irradiation (T=  С, neutron flux ~ n/sm 2 )

CONCLUSION 1. Conception of tritium breeding ratio measurement and irradiation of material samples has been proposed to irradiate of the samples and to estimate tritium breeder rate in ITER TBM by experimental method under ITER normal operation. 2. Canal design is developed for irradiation of ceramic lithium, neutron detector, material samples during plasma pulse in ITER and for fast its transportation to analytical laboratory. 3. Accuracy of tritium content measurement for lithium carbonate and lithium orthosilicate is 7 % and 10%.

1. Tritium Breeding Ratio (TBR) of DEMO / ITER The most important tritium cycle parameters : - tritium breeding ratio (TBR), - amount of tritium in the reactor, tritium balance - radiation safety parameters. ТВR = Q reactor / Q plasma (1) Q reactor – tritium amount breaded in plasma and in reactor blanket Q plasma - tritium amount burned-up in plasma.

TBR for the DEMO with ceramic blanket ~1.05. Sufficiently accuracy definition of tritium amounts breaded in a module (numerator in (1)) isn’t really possibly by continue measurements in purge-gas system. The most accuracy measurements can be done in case of tritium breeder and neutron detectors location in TBZ for short time and follow remove of its from TBZ after plasma pulse, delivery to an analytical laboratory for analyzing. Detectors can be located for one plasma pulse period

Accuracy of tritium content measurement in samples Δтв R = Δrеакtоr + Δplаsmа Δrеакtоr = Δ TBZ + Δd,d (D,D) (Dd,d) Δd,d = Δd,t * (Sd,d( t plasma )/ Sd,t( t plasma)) Δ TBZ ~ ΔLi-sample

Development and test of Tritium Breeding Ratio (TBR) monitoring systems -Development of TBRMS for TBM -out-pile and laboratory systems for investigation of sample deliver to TBM, -methods and analysis systems for measurement of tritium breaded in the samples

Problem of TBR Precision Measurement Q reactor

Conception of TBR Monitoring