Safety Ensuring in the Design of
Small and Medium Sized NPPs
V.M. Belyaev, A.N. Pakhomov, K.B. Veshnyakov
Technical Meeting on Challenges in the Application of the Design Safety Requirements for Nuclear Power Plants to Small and Medium Sized Reactors
Vienna, 4-8 September 2017
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OKBM Reactor Technologies: Experience and Development
Experience is the best of all evidences –
F. Bacon
•Proven reactor technologies and innovation solutions are available.
Foundation of proven technologies and
development
•Total number of reactor plants is 20 pcs. (including 7 RPsinstalled on the acting nuclear icebreakers).•More than 50 years of 3 generations of nuclear icebreakersoperation in the Arctic region.•Total operating time is more than 400 reactor-years.•Two innovation RITM-200 RPs have been supplied for the first ofa kind multipurpose nuclear icebreaker.
•Two RPs have been supplied for the FNPP “AcademicianLomonosov” confirming the efficiency of combining thefunctions of Chief Designer and Complete Supplier of KLT-40SRP.
•Key fields of activities:•- Standardization of engineering decisions for the entire powerrange;•- Increase of reliability, safety, manoeuvrability;•- Reduction of the scope of maintenance, increase of serviceoperation between repairs.
Experience in development and fabrication
of reactor plants for the floating nuclear
power plants
Great experience in development and
operationof nuclear icebreakers reactor
plants
Great experience in development and
operation of marine reactor plants
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ABV
KLT
RITM
VBER
Thermal power 300-1700 MW
Electric power 100-600 MW
Modular reactor based upon
marine technologies for land-
based and floating NPPs
Thermal power 175 MW
Electric power up to 50 MW
Integral reactor with forced
circulation for the multipurpose
nuclear icebreaker, floating and
land-based NPPs
Thermal power 150 MW
Electric power 38.5 MW
Serial modular reactors of nuclear
icebreakers and ships, for floating
and land-based NPPs
DesignRefueling
Interval, years
Service life,
years
Development
stage
ABV Type
10-12 50*
- The final design is developed for the prototype reactorplant and Volnolom floating NPP (1993).
- The feasibility study is developed for construction of thefloating NPP with ABV-6M for the Far North (settlementTiksi, settlement Ust-Kamchatsk, 2006) and the thermalNPP for Kazakhstan (City of Kurchatov, 2007).
- The land-based prototype test facility is in operation with100% natural circulation (at FSUE “NITI”).
- The final design in being developed for a transportablereactor plant under the contract with Minpromtorg (RFMinistry of Industry and Trade).
KLT Type
2.5-3 40* In 2011, a complete delivery was completed of two reactorplants for the first floating NPP Academician Lomonosov.
RITM Type
4.5-10 40*
Two reactor plants for the first multipurpose icebreaker(complete delivery in 2016) are being manufactured. Serialdeliveries of reactor units for two consequent nuclear ice-breakers will be in 2017 and 2018.
VBER Type
1.5 - 2 60
- Technical and commercial proposal for the two-unit NPPwith VBER-300 Reactor Plant (2002)
- Preliminary design of the reactor plant approved byScientific and Technical Board No. 1 and State NuclearSupervision Body (GosAtomNadzor) (2004)
- Technical assignment for the NPP design and for finaldesigns of the reactor plant, automated process controlsystem and heat-generating plant; Feasibility, Economy andInvestment studies for NPP with VBER-300 RP atMangistaus Region in Kazakhstan (2007–2009).
- Development of the 100>600 MW VBER RP power range(2007–2008).
- Research and development work on the NPP design withVBER-460/600 RP (2008–2011).
- Development of the VBER-600/4 RP based upon the heatexchange loop with increased capacity(2011–2012)
Thermal power 16-45 MW
Electric power 4-10 MW
Unified reactor plants with integral
reactors and 100 % natural
circulation in the primary circuit
for land-based and floating NPPs
* - possibility of extension up to 60 years
Marine Technology-Based Small and Medium NPP Designs Developed by JSC "Afrikantov OKBM"
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Application of Small Nuclear Power Sources
FLOATING PLANTS
MODULAR-TRANSPORTABLE
POWER UNITS
UNDERWATER POWER UNITS
GROUND-BASED PLANTS
•Autonomous heat and power supply to the consumers of hard-to-reach areas•Power supply to oil-production platforms•Desalinated water supply (in cooperation with desalination units)
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FPU
with KLT-40S RPs
Small CNPP
SPENT FUEL
AND RADWASTE
STORAGEREACTOR
PLANTS
STEAM-TURBIN E PLANTS
UNDERWATER TRENCH
145X45
DEPTH, 9 M
HYDRO ENGINEERING FACILITIES
HEAT
POINTDEVICES FOR DISTRIBUTING
AND TRANSFERRING
ELECTRIC POWER TO CONSUMERS
HOT WATER
CONTAINERS
SALT WET
STORAGE CONTAINER
THE DESIGN OF THE SMALL COGENERATION NUCLEAR POWER PLANT (CNPP) IS PILOT.
THE FPU IS BEING TESTED.
RP EQUIPMENT SUPPLY WAS COMPLETED IN 2011.
THE NPP STARTUP DATE IS 2019.
SUPPLY TO CONSUMERS IS AS FOLLOWS
ELECTRIC POWER 20A70 MW
HEAT 50A146 Gcal/h
Floating NPP Based on FPU with Two KLT- 40S RPs
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Floating NPPs are a New Class of Power Sources
� The power unit comprises two reactor plants, two turbine plants, electric-
power system, refueling complex, nuclear fuel and radioactive waste
storage, accommodations.
� An autonomous power unit is mounted on the non-self-propelled barge.
The number of offshore facilities and requirements for them are minimal.
� The power unit is supplied to the operation site by water on a turnkey
basis after completed acceptance tests.
� After completion of four cycles, it is transported to a specialized
enterprise to be repaired.
� It is possible to change the power unit location site.
� After decommissioning on termination of the service life, the floating
power unit is transported to its disposal site providing retention of the
“green lawn” state in the floating NPP operation area.
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Safety Related KLT-40C RP Design Features
SG and MCP are connected with reactor through short nozzles
� There are no lengthy primary circuit pipelines of big diameter
Steam generator vessel operates under the primary circuit pressure
� No safety valves to protect the steam generator vessel from excess
pressure;
� No primary coolant release while localizing a tube system leak
Use of Canned main circuit pumps:
� Absence of primary coolant leaks
� Absence of the sealing water system
� Absence of the lubrication system
Linking-up of all make-up system nozzles with “hot” sectors of primary circuit;
Presence of restrictions
� Maximum scale of possible primary circuit depressurization is 25 mm
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Promotion Ways to Increase FPU Commercial Appeal
•FPU with KLT-40S RP
•Total assigned life time - 40 years
•Time to intermediate repair - 12 years
•Time between core refueling – 2.5 – 3 years
•Refueling complex and Spent Fuel storage on the FPU
board
•Optimization of RP systems
•Exclusion of accommodation from the FPU
design
•“At shore” settlement
•Exclusion of refueling complex and storage of
spent fuel and solid radwaste from the FPU
design
• Floating technical support and maintenancebase with transportation to FPU location
•Maintaining of FPU operation without refueling
at the location site till dock (factory) repair
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•Standardization of the
main technical decisions
and equipment for NPP and
FPU as a whole
•FPU with RP KLT-40S
•Advanced FPU with RITM-200М RP
•Reduction of RP R&D duration
and cost due to standardization
of RP for multipurpose
icebreaker and FPU
•Service life – 40 years
•2 medium repairs
•Core power margin up to 3 TW·h
•Refueling complex and Spent
fuel storage at the FPU board•Ensuring of operation without refueling at location
site till dock (factory) repair
•Multipurpose icebreaker
•Service life – 40 years
•1 medium repair
•Core power margin
up to 7 TW·h
Advanced FPU – a New Concept of its Operation
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1. The RP has integral design of the reactor with forced circulation of
the primary coolant and remote gas pressure compensation system.
2. Composition and structure of the RP systems are designed
considering experience gained while developing the previous plant
generation, requirements of the up-to-date norm safety documentation,
ToR requirements with regard to weight-dimensional characteristics
and reduction of liquid radwaste.
3. The main design approach is rational combination of passive and
active safety means and trains, optimal use of the normal operational
and safety systems.
Passive pressure reduction and cooling down systems are
introduced (efficiency of the systems is confirmed by bench
testing);
Pressure compensation system is divided in two independent
groups to minimize diameter of coolant leak;
Main circulation path of the primary circuit is located in a single
vessel;
Header scheme of primary coolant circulation is introduced,
which ensures advanced vitality of the plant during SG and MCP
failures.
RITM-200М RP. Main Engineering Solutions
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KLT-40S and RITM-200М RP. Comparative Characteristics
Characteristic KLT-40S RITM-200М
Total assigned service life, h/year 300,000/40 320,000/40
Assigned life time/service life till factory repair, h/years
100,000/12 160,000/20
Number of medium repairs 2 1
Mass of two RPs in the containment, t 3743 2600
Containment dimensions for two RPs LхWхH, m 12х17.2х12 6.8х14.6х16.0
Core refueling interval, years 2.5 (3.0) 10
RCP power, kW 4х152 4х97
Minimal coolant temperature during hydraulic test at the end of operation, 0С
91 40
Passive heat removal, h 24 ∞
Time until core uncovery in a passive accident scenario with primary leakage, h
10 72
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Arrangement of KLT-40S RP and RITM-200M RP
in the Containment
RITM-200МKLT-40S
RP weight in the containment - 1300 t
RP dimensions in the containment– 6.8 х 6.7 х 16.0 m
RP weight in the containment- 1870 t
RP dimensions in the containment – 12 х 7.9 х 12 m
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KLT-40S and RITM-200М RP. Comparative Characteristics
CharacteristicFNPP with two RP
KLT-40S RITM-200М
1 Electric power (el.), MW 38.5х2 50х2
2 Staff ratio (for FRU), per/MW (el.) 0.8 0.5
3 FNPP/FPU Construction cost, rel.units 1/1 0.75/0.65
4 FNPP/FPU construction unit cost,
rel.unit/MW(el.)1/1 ~ 0.58/0.5
5 Energy prime cost, rel.un/MW*h 1 0.85
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SAFETY CONCEPT
� The safety concept of the reactor plants is based on state-of-the-art defense-
in-depth principles combined with developed properties of reactor plant self-
protection and wide use of passive systems.
� Properties of intrinsic self-protection are intended for power density self-
limitation and reactor self-shutdown, limitation of primary coolant pressure
and temperature, heating rate, primary circuit depressurization scope and
outflow rate, fuel damage scope, maintaining of reactor vessel integrity in
severe accidents and form the image of a “passive reactor”, resistant to all
possible disturbances.
� The RP designs were developed in conformity with Russian laws, norms and
rules for ship nuclear power plants and safety principles developed by the
world community and reflected in IAEA recommendations.
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Safety Levels
1
2
3
4
5
1 – FUEL COMPOSITION
2 – FUEL ELEMENT CLADDING
3 – PRIMARY CIRCUIT
4 – RP CONTAINMENT
5 – PROTECTIVE ENCLOSURE
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Emergency Reactor Shut Down System
System of liquid absorber
injection (pumps and valves
are connected to emergency
diesel generators)
1 Reactor
2 CRD mechanisms
3 System of liquid absorber injection
4 Make-up and born control systems
5 Electric power circuit-breaker by pressure
4
Electric power circuit-breakers by pressure provide de-energizing of CPS drive mechanisms (reactor shutdown):
� by pressure increase in the primary circuit
� by pressure increase in the containment
Electromechanical system of
reactivity control.
Automatic insertion of
absorber rods in the core
under gravity
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Emergency Reactor Heat Removal Systems
1 Reactor
2 Steam generator
3 Reactor coolant pump
4 Water tank with in-built heat exchangers
5 Purification and cooling down system
6 Technological condenser
Technological
condenser
Purification and
cooling down system
6
Passive cooling trains with water tanks and in-built heat exchangers ensure reliable cooling
during 24 hours without tank make-up.
Design option (KLT-40S)
Hydraulically operated distributors
Opening of pneumatically driven valves of ECCS
passive trains by primary circuit overpressure
(cooldown)
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Design option (RITM-200М)
Steam
Steam generator
Steam to atmosphere
Steam to atmosphere
Core
Water Water
Steam
Heat exchanger
Air heat exchanger
Application of combined systems
with heat transfer to water and air
with no time limitations
Emergency Reactor Heat Removal Systems
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Emergency Core Cooling Systems
1. Reactor
2. Steam generator
3. Reactor coolant pump
4. ECCS hydraulic accumulator
5. Makeup system
6. Recirculation system
1
2
3
4 4
5
6
Passive emergency
core cooling system
Recirculation and repair cooling
down system
(pumps and valves are connected
to emergency diesel generators)
Emergency make-up system
(pumps and valves are connected to
emergency diesel generators)
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Innovative Safety Systems
Active and passive EHRS
- A single initiation
algorithm in active and
passive modes
- Effective passive heat
removal under low
temperature in the primary
circuit
Containment against high pressure (1
МPa)
- Counterpressure on the coolant
leaking from reactor
RP safety ensuring during unlimited period of time using passive means in all types of
accidents including LOCA of more than three days
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System of Emergency Pressure Decrease in Containment
SEPD (preservation of safety
barrier – containment)
- is based on the passive
operating principle
- interconnects areas in the
containment
- condensates the steam on
heat exchangers in the
containment and due to
barbotage
Conditioning
system
blower
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Analysis of a Postulated Severe Accident
Retention of the molten corium in the reactor vessel
Results of the sever accident analysis
- Absence of submelting of the RPV wall
- Reliable heat removal from the reactor
bottom outer surface is ensured
- Reactor mechanical properties are
maintained at the level sufficient to ensure
load bearing capacity despite appeared
temperature difference
- Radiation dose for population in case of
beyond design accident with severe core
damage does not exceed 5 mSv
Reactor
pressure
vessel
Molten
corium
Reactor
caisson
Cooling water supply
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Resistance to External Impacts
The RP is substantiated to be resistant to external impacts:
� Rolls and tilts in accordance with the requirements of the Russian Maritime
Registry of Shipping;
� Impact resistance of not less then 3 g;
� Reactor shutdown and containment preservation in case of flood, including
in case of turnover;
� Crash of a helicopter with the mass of 10 t from the height of 50 m.
The performed comprehensive analysis of the FPU resistance in case of
natural impacts has demonstrated that there are no radiation
consequences:
� In case of a seismic impact of up to X-XII degrees with vertical acceleration
not exceeding 1.8 m/s2;
� Within 24 hours for sure after full FPU blackout;
� In case of a tsunami due to appropriate location site selection and the use
of purpose-built hydraulic structures.
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Radiation and Environmental Safety
� POPULATION RADIATION DOSE RATE UNDER NORMAL OPERATION CONDITIONS AND
DESIGN –BASIS ACCIDENTS DOES NOT EXCEED 0.01% OF NATURAL RADIATION
BACKGROUND
� POPULATON IS ALLOWED TO LIVE IN THE PROTECTIVE ACTION PLANNING AREA.
NO COMPULSORY EVACUATION PLANNING AREA
1 km
BUFFER AREAPROTECTIVE ACTION
PLANNING AREA
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Non-proliferation Issues
KLT-40 S with Refueling at a Site
FNPP
transportation
with spent fuel
inside the
reactor and
storage
Fresh fuel
transportation
FNPP
transportation
with fresh fuel
inside the
reactor
Fu
el co
mp
lex
Fabrication
of fresh fuel
Reprocessing
Discharge of
spent fuel
Loading of
fresh fuel
into the
reactor
Waste storageFloating NPP
Fresh fuel loading
Spent fuel
unloading
Temporary fuel
storage
Ind
ustr
ial
co
mp
lex
New FNPP
construction
Retired FNPP
disposal
FNPP repairing
Reactor
Local infrastructure
Exporting country Importing countryThird
country
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Non-proliferation Issues
KLT-40 S with Refueling at a Site
FNPP transportation with spent
fuel inside the reactor
Fu
el co
mp
lex
Fabrication
of fresh fuel
Reprocessing
Unloading and
temporary storage
of spent fuel
Loading of
fresh fuel
into the
reactor
Waste storage
Floating NPP
Ind
ustr
ial
co
mp
lex
New FNPP
construction
Retired FNPP
disposal
FNPP repairingReactor
Local infrastructure
Exporting country Importing countryThird
country
FNPP transportation with fresh
fuel inside the reactor
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Conclusion
� JSC “Afrikantov OKBM” has developed and is implementing innovative
Reactor plant designs enabling to create a power range of NPPs of various
applications and arrangements.
� The designs provide high technical-and-economic indices, referentiality of
the applied technical solutions and their safety is well substantiated and
confirmed by many years operation of analogues and prototypes.
� RITM-200M Reactor plant has advantages from the viewpoint of safety,
weight-size parameters and technical-and-economic indices.
� From the viewpoint of non-proliferation, FNPP with reactors, which operate
without refueling at a site, are the most attractive. Proliferation resistance
of such NPPs may be estimated to be very high.
