Potential for International Standards and

Licensing in Fusion

Presented by Tianlin QIAN

China National Nuclear Corporation

7th IAEA DEMO Programme Workshop

Content

Major challenges in safety assessment of fusion facilities

Main differences between fusion facilities and fission

reactors considering nuclear regulation

Suggestions for international standards and licensing for

fusion facilities

2

Major challenges in safety assessment of

fusion facilities

3

Major challenges

With the development of fusion research, fusion power facilities may only be

10 -15 years away. The detailed design phase may start in the next 5 to 10

years, but it should be regulated due to the nuclear process.

Fusion power facilities are not covered by the current nuclear safety

standards framework. The lack of fusion specific regulatory framework,

makes a regulatory vacuum.

The major challenges in safety assessment from my opinion are:

1) Classification of fusion facilities

2) Applicability of nuclear regulation for fusion facilities

3) Identification of the potential hazards in fusion facilities

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Classification of fusion facilitiesIn China, the pathway toward fusion-DEMO is from HL-2A(M)/EAST/J-TXT, to current ITER, to

next CFETR and DEMO.

HL-2A(M)/EAST/J-TXT are tokamak experiment facilities, which are classified as radiation

generation device.

ITER is a fusion experimental reactor classified as basic nuclear installation, which is the first

fusion facility supervised by the nuclear safety administration(ASN)

The classification of CFETR and DEMO are not confirmed in China.

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HL-2M EAST J-TEXT

Experimental Facility ITER CFETR DEMO· Steady state advanced operation

· Advanced divertor, high power

H&CD, diagnostics

· Radiation generation device

· Steady state burning plasma

· Hybrid burning plasma

· Basic nuclear installation

· Fusion technology engineering

validation

· Demonstration of fusion technology

· Research reactor? other nuclear facility

requiring supervision? radiation generator?

· electricity generation into grid

· Safety, reliable, efficient

· Research reactor? other

nuclear facility requiring

supervision? radiation

generator?

Classification of fusion facilities

The fusion facilities should follow the laws including environmental protection,

public heath, and prevention and control of radioactive pollution.

The classifications of all the nuclear installations depend on their risks. The

classifications of fusion facilities may focus on:

➢Energy source(decay heat)

➢Neutron source

➢Radiative product

➢Tritium

➢Hazards

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Classifications of

fusion facilities

Nuclear reactor:

power reactor or

research reactor

Radiation generator:

generate radiation by

accelerating charged

particle

Other nuclear facility

requiring supervision

Nuclear regulation

Current national and international nuclear regulatory landscapes have been

shaped by the special characteristics associated with nuclear fission.Despite

different principles, Some safety regulations are applicable for the fusion,

such as the management rules for radioactive substance, nuclear material,

safety equipment.Advantages

➢Existing regulatory framework

➢Existing standards / guides for fission power plants

➢Existing adaptable regulatory framework

Disadvantages

➢Unduly restrictive

➢Inconsistent with hazard potential

➢Some standards / guides not fully applicable to fusion facilities7

Hazards identification

Potential risks for the fusion facility can be classified according

to their origin and consequences:

nuclear risks with potential radiological impact (neutrons, tritium,

activated materials)

non nuclear risks (chemical, toxic, mechanical, thermal, electrical,

electromagnetic, etc.) with potential radiological impact in case of

accident, with a distinction made between the following:

➢ internal hazards originating in fusion facilities

➢ external hazards originating from the fusion facilities surroundings

non nuclear risks with potential impact to personnel

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Hazards identification

In fusion, Safety important buildings, structures and components should

be designed to withstand internal and external hazards, particularly, to

ensure the availability of function provided by safety important

component.

Typical identification of hazards need to be considered: ➢ Radiation

➢ Release of radioactive material (T, AP, ACP, dust)

➢ Toxic material (Be, V, lead etc.)

➢ Electromagnetic field

➢ Vacuum

➢ Cryogenic fluids

➢ Chemical reaction

➢ Rotating machinery

Main differences between fusion facilities and

fission reactors considering nuclear regulation

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Safety Features of Fusion Reactor

According to the fusion DEMO research, the fusion and fission facilities

are significantly different in nuclear process. Also the potential hazard

and accident consequence of a fusion power facility looks much less

than fission power.

The main differences of safety are:

Key Safety Issues Fission Fusion

Reactivity control Criticality potential

No criticality feature

The reactivity control in fission is not

important in fusion

Decay Heat RemovalAbout 8% of full power heat at

shut-down

About 1% of full power heat at shut-down,

and without the risk of core melting

Radioactive confinement Fission products and actinidesTritium, activated products (AP, including dust)

and activated corrosion products (ACP)

Spent fuel Large quantities No spent fuel

Core/power protection Multiple systems required to

prevent fuel and core damageTerminate plasma easily

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Radioactive Source Terms

• Radioactive source terms in fusion reactor (Tritium, activated products (AP, including dust) and activated

corrosion products (ACP)) are different. There is no spent fuel in fusion reactor.

• The safety design rule shall consider these features.

Objective of safety

Objective of safety

Provisions on design safety of nuclear power plant (HAF 102):General objective of safety : to establish and maintain the effective defense against radiological

hazard, in order to protect the public and environment from radioactive hazards

In order to achieve the objective, the following measures must be taken:

1.Control the radioactive material to the environment under operation

2. Limit the possibility of events leading to out of control of the reactor core, spent fuel,

radioactive waste, or any other radiation source in a nuclear power plant

Suggestion:

General objective of safety is consistent in fusion. The dose of radioactive material to the worker

and environment need to be ensured for fusion reactor.

There is no spent fuel in fusion reactor. The radioactive waste in tritium plant and hot cell should

be considered.

Objective of safety

Nuclear Regulatory in China（GB18871）(mandatory standard)Occupational exposure Public environment

Normal

Average dose for five consecutive years≤20mSv/yr；Any year effective dose ≤50mSv/yr；Eye crystal equivalent dose ≤150mSv/yr；Skin equivalent dose ≤500mSv/yr；

Dose ≤1 mSv/yr；Eye crystal equivalent dose≤15mSv/yr；Skin equivalent dose≤50mSv/yr；

special situation

Average dose for ten consecutive years≤20mSv/yr；Any year effective dose≤50mSv/yr；When the amount reaches 100mSv，examination is needed

If average dose in five consecutive years≤1 mSv/yr，A single year can increase≤5 mSv/yr

ITERbasic design condition

worker Public environment

NormalALARA，the maximum individual dose≤10mSv/yr；average individual dose≤2.5mSv/yr；

The device releases less than the authorized limit ；≤0.1 mSv/yr；

incidentAs low as possible ；Each event ≤10mSv；

Each event ≤0.1 mSv；

accidentConsider the constraints on the management of accidents and the post-accident situation；

When less than 10mSv, no immediate or delayed response measures (such as isolation and evacuation) will not limit the use of animal products or vegetable products ；

beyond basic design condition

Hypothetical eventNo cliff effect ；Possible response in limited time and space ；

0.25mSv/yr（GB6249）

Basic standards for protection against ionizing radiation and for the safety of radiation sources （GB18871）Regulations for environmental radiation protection of nuclear power plant (GB6249)

Basic safety function

Basic safety function

Provisions on design safety of nuclear power plant (HAF 102):The following basic safety functions must be ensured in all state of the nuclear power plant:

In order to achieve the objective, the following measures must be taken:

1.Control of reactivity

2.Emission of reactor core heat, emission of spent fuel heat in the spent fuel storage facility

3.Confining radioactive substance, control of operation emission, and restraint of accident

emission

Suggestion:

The basic safety function has a difference. The basic safety function of fusion reactor should

focus on radioactive confinement and radiation exposure restrictions, not emphasis on reactivity

control. The decay heat after fusion power shutdown is lower than fission, and it can be

removed more easily. There is no spent fuel heat in fusion reactor.

Radioactive effluents in fusion facilities

Gaseous effluents (detritiation system, venting system)

Tritium

Activated dust

ACP

Activated gases (Ar-41, C-14, etc.)

Tritiated aerosol particle (avoided by HEPA filters)

Liquid effluents

High-level radioactive liquid effluents that contain a mixture of tritium and activated

corrosion products (primary cooling system, residual water in Hot Cell, etc.)

Very low-level radioactive effluents that may contain a mixture of ACP, dust or tritium

(ground washing in controlled or supervised radioactive buildings, laboratories in the

Personnel Access Control Building, etc.)

Very low-level radioactive effluents that may mainly contain tritium (secondary loop,

external air humidity condensates, tritium plant, etc.)16

General design basic

General design basic

Provisions on design safety of nuclear power plant (HAF 102):The conditions of the nuclear power plant must be determined

The conditions of a nuclear power plant is usually included:

1.Normal operation

2.Expected operation event

3.Design basic accident

4.Design extension condition, including core melting accident

Suggestion:

The fusion reactor does not involve serious decay heat, and there is a significant difference in

the consideration of the design extension condition, especially the core melting . The multiple

failure accidents may be considered in design extension condition.

Nuclear Regulation applicability analysis

Issue Applicability

Spent fuel InapplicabilityNo spent fuelTritium plant and hot cell should be considered

Basic security function DifferentRadioactive inclusion and radiation exposure restrictions, not emphasis on reactive control

Power plant operation condition

DifferentLow decay heat, no core melt

System design requirements

Much differentMore complex

Fuel manage DifferentStorage and transport of tritium should be considered

Aircraft impact Need discussInherent safety

Proven engineering practice

The verified neutron irradiation condition is not comparable to fusion reactor

Nuclear Regulation applicability analysis

Control Regulation Applicability

Safety classification Differentclassification should be based on safety function determination

defense in depth Needthe requirement may lower according to no core meltTritium plant should be considered

Emergency response Differentoffsite services such as electricity supply and fire service need discuss

Radioactive limit (tritium limit ) Need discuss

Necessity of containment Need discussNot consider in CFETR and ITER

Safety measures can be added, but it is difficult to subtract

Suggestions for international standards and

licensing for fusion facilities

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Suggestions

Assessment of the international approaches to fusion

regulation

• It is useful to study different national fusion regulatory, including possible different

legal definitions of fusion reactors

• It will contribute to implementation of fusion regulation in different countries

• But it shall be careful, the regulatory framework is unique in each country and is

based on law. The safety principle may be more useful

Suggestions

Identification of Applicability for Regulation and standards of

fission facilities

• It will be a good starting point to review the applicability of the safety standards

from current regulation for fusion

• Some current safety regulation can be used in fusion, such as the regulations for

management rules for radioactive substance, nuclear material, safety equipment

• Through the applicability analysis, applicable regulations and deficiencies of

regulations can be determined. The special regulation required for fusion can be

added to the current regulatory framework. This will be more efficient.

Suggestions

Proposal for International harmonised safety requirements and

standards• It is the first step to find the key inputs for establishing the fusion specific design safety

requirements and standards

• There are good references for key inputs from ITER, JET, also from the DEMO design

experience in the past decade years

• The current gaps in the information / knowledge

− Hazard identification and initial accident event

− New material and radioactive substance

− Tritium behavior and handling

− Reliability of new type equipment and complicated system

− …

• The gaps can be identified and get common agreement in international cooperation. It is

also helpful to encourage the labs/institutions to take effort to investigate and solve by

collaboration research

Thank you very much

for your attention

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