Assessment of the tritium resource available to the fusion ......Forecasts of Canadian tritium inventory, with three different ITER schedules Michael Kovari Slide 10 Canada will not

CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority.

This work was part-funded by the RCUK Energy Programme [grant number EP/I501045]

and the European Union’s Horizon 2020 research and innovation programme.

Assessment of the tritium

resource available to the

fusion community

Michael Kovari

[email protected]

More detail: EFDA_D_2MT7EG - PMI-2.1-T003-D001 - Report on the assessment of the tritium resource available to the fusion community

mailto:[email protected]

https://idm.euro-fusion.org/?uid=2MT7EG

Introduction

Slide 1 Michael Kovari

• The tritium from the CANDU reactor production programme may not be sufficient to start DEMO.

• ITER will be severely delayed, and if DEMO is similarly delayed then all of the CANDU reactors will have been shut down, while the civilian tritium stockpile will have decayed.

• More than one fusion reactor may be built after ITER • Fusion Nuclear Science Facility (FNSF), • Component Test Facility (CTF), • Power reactors – Korea, China… ?

• Where will the tritium come from?

• There is no published schedule.

• Scott Willms has kindly provided an estimate:

– starting (at a significant rate) in 2032

– 12 kg total.

Tritium required for ITER

Slide 2 Michael Kovari

• A non-trivial exercise!

• Literature varies from 0.5 to 18 kg

• Fuelling circuit has much bigger throughput,

• But blanket has bigger volume.

• Urgorri et al (WCLL blanket):

– 15 g/day permeation into water coolant.

– Inventory in the coolant??

• Santucci et al:

Tritium required to start up a reactor

Slide 3

T inventory in PbLi (g) T inventory in PbLi + coolant + steel (g)

HCLL 9-23 17 – 23

WCLL 14 – 19 19

Michael Kovari

These estimates may not tell the whole story.

• Gases in metals:

– “lattice” solubility (interstitial sites)

– atoms bound to ‘traps’ (inclusions, dislocations, grain

boundaries).

• When experiments use high partial pressure gases, it

may be that most of the traps are filled.

• When results are extrapolated to low pressures, the

trapped gas concentration may not reduce according to

Sievert’s law, or at all.

• Irradiation will increase trapping

• Even liquids contain impurity atoms.

Tritium required to start up a reactor (2)

Michael Kovari Slide 4

• Difficult tokamak physics!

• Up to 170 MW of neutral beam power

• Start with no tritium at all:

– tritium from DD fusion accumulates in a few seconds,

Start-up with deuterium-rich fuel


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Starting tritium inventory (g)

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Time required to reach 50:50 mix


TBR (DT) = 1.1 Tritium production ratio (DD) = 0.72

Fuel burnup = 2% Tritium residence time in breeding system (h) = 3

Availability = 0.7 Fractional T loss and retention in blanket and tritium system = 0.05

T residence time in fuelling system (h)

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Time required to reach 50:50 mix (2)


TBR (DT) = 1.1 Tritium production ratio (DD) = 0.72

Fuel burnup = 2% Tritium residence time in breeding system (h) = 3

Availability = 0.7 Fractional T loss and retention in blanket and tritium system = 0.05

T residence time in fuelling system (h)

Start at 10% tritium: interest on the capital at 5% plus electricity: $1.4 million per gram of tritium saved.

• 5 reactors have been successfully refurbished in

Canada.

• Extend the reactor’s life for an additional 30 (?) years.

• 10 reactors are due for refurbishment

• Darlington unit 2 was taken off-line on 14 October ready

for work to begin.

Canadian production and stocks


Refurbishment and life extension - Canadian Nuclear Safety Commission. 2014, http://nuclearsafety.gc.ca/eng/reactors/power-plants/refurbishment-and-life-extension/index.cfm. http://www.durhamregion.com/news-story/6911795-refurbishment-at-clarington-nuclear-station-underway/

http://nuclearsafety.gc.ca/eng/reactors/power-plants/refurbishment-and-life-extension/index.cfm











Tritium light sources

Forecasts of Canadian tritium inventory, with three

different ITER schedules


Canada will not be able to provide 10 kg for DEMO in 2060.

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kg

ITER burn starts 2032



“burn” is when deliveries exceed 0.5 kg/year.

Heavy water reactors outside Canada


Operational

Under construction

Planned

Tritium available 2060

India 18 4

4

14.5 kg

China 2 1.7 kg

Argentina 3 1.6 kg

Romania 2 2 5.1 kg

Korea 4 2.5 kg

Total 25 kg

tritium generated 2.22E-04 kg/FPY/Mwe Reactor lifetime 50 years Station below 1 GWe ignored: too small for economical tritium extraction Overall reactor capacity factor (including refurbishment outages) 70% DEMO start date 2060 No consumption or loss

Lithium could be irradiated for additional tritium production.

1. The “low void reactivity fuel bundle”: – burnable absorber in the central element of the bundle (enriched fuels)

– Never used.

– Lithium absorber – 200 g/year tritium?

2. Adjuster rods: – cobalt-59 rods for cobalt-60 production

– Lithium rods – 130 g/year tritium?

3. Dope the moderator with lithium?

4. Dope the liquid zone-controllers with lithium?

Need to change the operating procedures!

Regulators will not accept this for existing plants.

BUT: New CANDUs planned.

These are reasonable possibilities.

Other options for heavy water reactors


Commercial light water reactors


Watts Bar


9.7 mm

Tritium-producing burnable absorber rod

In 1999 the Department of Energy said,

No significant safety issues were identified.

(There were, in fact, safety issues. Tritium permeation into

the coolant was much more than expected.)

Tritium is produced without any significant modifications to

these facilities and does not affect electricity production.

Licensing and operation

Michael Kovari

• AP1000 has burnable absorbers

• EPR also has burnable absorber rods, but in these the

gadolinium absorber is mixed with uranium dioxide.

Adding lithium with no uranium would impair the

reactivity profile.

• Licensing would be very difficult in both cases.

• The Japan Atomic Energy Research Institute actually

did produce tritium on a trial basis in the 1980s.

Other light water reactors

Michael Kovari

Production in a particle accelerator is probably feasible.

Particle accelerator (APT)

Michael Kovari

APT

(basic configuration)

Government

estimates

ESS

Beam power 100 MW 5 MW mean

Electric power 312 MWe 35 – 45 MWe

Tritium production 1.5 kg/year n.a.

Capital cost $2.8 billion (1999)

(total undiscounted

cost over 40 years:

$7.5 billion)

€1.8 billion

Ratio

20

8 (?)

1.6 (?)

In my opinion, this is a scheme to create

huge industrial contracts.

One boosted fission bomb requires ~ 4 g of tritium.

The export of tritium and tritium handling equipment to non-

signatories of the Nuclear Proliferation Treaty has already

resulted in three prison sentences.

Tritium is not regulated under the IAEA Safeguards regime.

USA has removed all references to tritium being a “material

of strategic importance”.

But the risk of diversion must be studied in depth.

Proliferation

Michael Kovari

1. Tritium can be generated in any fission reactor or other strong source

of neutrons.

2. Start-up with deuterium-rich fuel would delay power production by up

to 6 years (depending on assumptions), and is not economically

sensible.

3. The USA has started producing tritium in a commercial light water

reactor.

4. The tritium required to start DEMO is uncertain within a wide margin.

5. Ontario may be able to supply 5 kg for fusion in 2060, but not 10 kg.

6. There are many heavy water reactors outside Canada. Romania has

definite plans to extract tritium from the heavy water, and other

countries may do the same. Each might be able to provide a few kg

by 2060.

7. The production of tritium in CANDU and other heavy water reactors

could be increased by using lithium targets.

Conclusions

Michael Kovari

8. If a reactor is started up around 2060, Canada, Argentina, China,

India, Korea and Romania will be able to ensure enough tritium for 1

or 2 machines:

– build, refurbish or upgrade tritium extraction facilities;

– extend the lives of heavy water reactors, or build new ones;

– reduce tritium sales;

– boost tritium production in remaining reactors.

9. If DEMO starts well beyond 2060, and heavy water reactors are all

shut, then light water reactors will be the only remaining source.

10. Minimise tritium inventory:

– experimental research in solubility and permeation; extraction

from the primary coolant; and improving the burn-up fraction.

11. The risk of diversion is a major concern, and must be studied in

depth.

Conclusions (2)

Michael Kovari

Thank you

1. Tritium can be generated in any

fission reactor or other strong source

of neutrons.

2. Start-up with deuterium-rich fuel is not

economically sensible.

3. The USA has started producing

tritium in a commercial light water

reactor.

4. The tritium required to start DEMO is

uncertain within a wide margin.

5. Ontario may be able to supply 5 kg

for fusion in 2060, but not 10 kg.

6. There are many heavy water reactors

outside Canada. Romania has

definite plans to extract tritium from

the heavy water, and other countries

may do the same. Each might be

able to provide a few kg by 2060.

7. The production of tritium in CANDU

and other heavy water reactors could

be increased by using lithium targets.

8. If a reactor is started up around 2060,

Canada, Argentina, China, India, Korea

and Romania will be able to ensure

enough tritium for 1 or 2 machines:

– build, refurbish or upgrade tritium

extraction facilities;

– extend the lives of heavy water

reactors, or build new ones;

– reduce tritium sales;

– boost tritium production in

remaining reactors.

9. If DEMO starts well beyond 2060, and

heavy water reactors are all shut, then

light water reactors will be the only

remaining source.

10. Minimise tritium inventory:

– experimental research in solubility

and permeation; extraction from the

primary coolant; and improving the

burn-up fraction.

11. Risk of diversion is a major concern.

EFDA_D_2MT7EG - PMI-2.1-T003-D001 - Report on the assessment of the tritium resource available to the fusion community




















Back-up slides


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Tritium production in Canada

Commercial demand - estimate

Upper estimate for tritium demand

ITER requirement

ITER + 5 year delay

ITER + 10 year delay


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Inventory (10 year ITER delay)

Cumulative ITER requirement

Documents

Assessment of the tritium resource available to the fusion ......Forecasts of Canadian tritium inventory, with three different ITER schedules Michael Kovari Slide 10 Canada will not