MAJOR TECHNICAL PARAMETERS
Parameter Value
Technology developer, country of origin StarCore Nuclear, Canada
Reactor type HTGR
Coolant/moderator Helium/Graphite
Thermal/electrical capacity, MW(t)/MW(e)
Block One: 35 / 14 Block Two: 50 / 20 Block Three: 150 / 60 One to six modules/plant
Primary circulation Forced
NSSS Operating Pressure (primary/secondary), MPa
7.4 / 6.7 Core Inlet/Outlet Coolant
Temperature (oC)
280 / 750 Fuel type/assembly array TRISO Prismatic
Number of fuel assemblies in the core Block 1: 90; Block 2: 126; and Block 3: 324
Fuel enrichment (%) 15
Core Discharge Burnup (GWd/ton) 60 GWd/t / 6 % Refuelling Cycle (months) > 60
Reactivity control mechanism 2 x 6 Rotary/Automatic deployment when gas flow lost Approach to safety systems Passive; Containment 1: TRISO;
Containment 2: RPV/ETS-1 Helium System;
Containment 3: Silo
Design life (years) 40 – 60
Plant footprint (km2) 1 (up to 1 Hectare)
RPV height/diameter (m) Block One and Two: 7.4 / 2.6 Block Three: 9 / 3.2
RPV weight (metric ton) Block One: 75; Block Two: 90;
Block Three: 150
Seismic Design (SSE) 0.25g
Fuel cycle requirements / Approach LEU/Temporary storage in Silo at plant
Distinguishing features RPV 30 Metres below grade in hardened silos
Design status Pre-conceptual/conceptual
design
1. Introduction
Founded in 2008, StarCore had the first major Technical Review at Argonne National Laboratory in 2013, and the last major Due Diligence (technical and business) review in 2019. StarCore is teamed with TREDIC Corporation (UK), a global infrastructure developer to export plants from Canada to all compliant Nations around the Globe. StarCore provides risk free, inherently safe, Generation IV Small Modular Reactor (SMR) power to off-grid and edge-of-grid locations. Our operations can provide clean electricity for industrial and consumer use, high temperature thermal energy for down-stream minerals processing, desalinated or purified water for irrigation or for those people without clean water sources, and wide-band internet for medical and educational use.
StarCore’s business model is predicated on a ‘Build, Own, Operate and Decommission’ (BOOD) basis, generating revenue and profit from Power Purchase Agreements (PPAs) and off-take arrangements with both national and local governments, and private enterprise. The StarCore business plan therefore brings with it a very low financial burden and StarCore will be responsible for obtaining all the necessary licenses and
STARCORE (StarCore Nuclear, Canada,
certification.
2. Target Applications
Serving remote communities to provide energy access and combat energy poverty is an important part of StarCore’s vision. In the developing countries there are more than two billion people who are either without electricity or who get power from diesel generators at very high cost. Many countries lack supplies of clean water and desalination-only plants are attractive to them. We are aware that we cannot just bring energy to a remote community – we must also bring some type of environmentally suitable industry, so the people have a future. We include 100 km HVDC transmission lines in our cost estimates, and so we can connect plants to residential and manufacturing sites. Remote mines are also an ideal market for StarCore, since they tend to be in remote locations and energy costs are high.
3. Main Design Features
Design PhilosophyStarCore is designed to operate in the harshest environment in remote locations anywhere in the world. To this end the reactors are contained in steel-walled concrete silo structures 30 metres below grade. Each reactor silo has two supporting silos with their access hatches in the refuelling room, also below grade. This room is filled with helium at low pressure during refuelling operations, which are carried out by an automatic system.
StarCore plants have between one and six reactors per plant, giving us a range of outputs between 14 MW(e) and 360 MW(e). The plants are load-following, and can also output High Temperature Gas or Steam, with the outputs dynamically changed as required.
The plants meet all planned Remote Siting Requirements, which include that they must be: Inherently Safe;
Passively Secure; Load Following; Fully Automated; Have a Remote Shutdown (Intervention) Capability; and after suitable qualification (subject to local regulations) be operated with a zero-radius exclusion zone.
The plants also have 69 KV 100 km HVDC transmission lines included in the cost of the plant. The StarCore Build-Own-Operate-Decommission Business Plan includes all capital costs, licensing, operating and decommissioning logistics, thus eliminating the cost of entry to all countries and communities. The HVDC is inverted to local frequency standards.
Reactor Core
The prismatic core is made up of hexagonal graphite blocks that are 360 mm across the flats and 793 mm long.
Cylindrical fuel compacts (26 mm diameter and 39 mm long) are inserted into holes drilled in the graphite blocks, and burnable (neutron) poison elements will also be inserted as needed. The helium flow will be through vertical holes drilled in the blocks. The number of blocks used depend on the output of the core.
The helium coolant enters at the bottom of the core, flows up the outside including through the reactivity control mechanisms, and then down through the core prismatic blocks. There are automatic bi-stable valves at the inlet and outlet, which seal off the core in the event of pressure loss.
Reactivity Control
The core has vertical rotary reactivity control rods with a neutron reflector on a semi-circular rotating half- cylinder. There are two sets of 6 control rods each with a different deployment mechanism that deploys the controls if helium flow or pressure is lost. The reactivity control mechanisms use the helium pressure differential across the core to stay stowed; in the event of pressure or flow loss they automatically deploy.
Reactor Pressure Vessel and Internals
The primary containment boundary is the TRISO fuel microsphere; the second is the Energy Transport System (ETS-1) with the nuclear system containing the RPV, piping, pumps and first stage intermediate heat exchanger. IHX-1. There are helium scrubbers in ETS to remove trace elements of radioactive dust and tritium.
Reactor Coolant System
The first stage coolant Energy Transport System (ETS-1) is helium at 7.3 MPa; this then transfers energy to ETS-2 through IHX-1 which contains nitrogen at 6.7 MPa. Nitrogen is used in this system at this pressure to minimize delta-P across IHX-1 and allow compact exchanger designs to be sued; in addition, the pressure gradient ensures that any gas migration will be in the direction of ETS-2.
The Nitrogen in ETS-2 then passes to an aero-derivative gas turbine that has an annular heat exchanger in place of the usual burner cans, and the turbine exhaust gas at 300 oC can be used for district heating or cooling.
The energy in ETS-2 can also be sent to a heat exchanger that provides high-temperature gas or steam to external plants.
Safety Features
The TRISO fuel exhibits a very strong negative temperature coefficient. As the fuel temperature increases the neutron energy also increases; this effect reduces the neutron cross sections and lowers the number of fissions and thus the power level. The result of removing all reactivity controls and shutting off the primary and secondary cooling systems will result in the core becoming stable with an output of 600 kW(t), which will be dissipated to the outside of the silo through vestigial fins into iso-thermal layer of the surroundings. The
prismatic core is attractive in this regard since the thermal pathways are better than those in pebble bed cores.
StarCore also has automatically deployed reactivity controls and inlet and outlet shutoff valves that are deployed if helium pressure or flow is lost. In a worst-case accident, where all control mechanisms fail, and the helium is exhausted to atmosphere the reactor will not suffer any catastrophic failures or radiation release.
A core meltdown type of event simply cannot happen; in the worst case the core will remain several hundred degrees C below TRISO microsphere failure temperatures.
4. Plant Safety and Operational Performance
Most nuclear plant control systems today rely on operators to determine the correct course of action in complex circumstances; nearly all reactor accidents and failures have been the result of incorrect operator techniques.
This is not practical for remote locations, and the StarCore Reactor Plant will be fully automatized using on- site hardware and software.
StarCore’s remote control technology will provide full-time monitoring and the ability to shut down the plant from StarCore Central or regional administrative centres by satellite links (2xGEO and 1xLEO) and reduce on-site personal to only maintenance workers. This design for fully automated operation with ‘remote monitoring and intervention (shutdown)’ is the StarCore Automated Reactor System (STARS) and has been the subject of an independent review by the former Atomic Energy Canada Limited (AECL) and the Canadian National Laboratories (CNL).
5. Instrumentation and Control Systems
StarCore owns the Intellectual Property to a modern fully automated control system design (the STARS HyperVector Control System) previously used in many safety-critical aerospace systems. There are many benefits that this control system technology brings, including automatic failure prediction for every system or component in an arbitrarily complex application; alarms that uniquely identify any specific failures that have occurred or are predicted; controls that prevent wrong commands or actions ever being taken, and automatic responses to arbitrarily complex failures.
The system is named after the manifold in n-dimensional state space that define the operational limits of the systems and components; these are represented by n-vectors, or HyperVectors, defined as complex data in the imaginary plane. The states are defined for every component in the plant, recognize system operations, and predict - in real time - any failures that may occur by calculating the state vector and time-to-state-operational- boundary for all components.
6. Plant Layout Arrangement
The plant has from two to six hardened silos at the base of the turbine hall; up to three turbine halls can be accommodated in each plant. The main body of the plant is constructed of high-performance modules that are bonded into a single monocoque structure and is designed to be capable of resisting standard man-portable weapons such as RPGs. The plant is designed to meet a Beyond Design Basis Accident (such as an aircraft or bomb) that destroys all above-ground facilities without causing any nuclear contamination.
7. Design and Licensing Status
StarCore has completed the initial design needed to develop Supplier Approval Procedures which resulted in an Approved Supplier List and a Hardware Readiness Assessment. The StarCore Team includes direct-hired StarCore personnel responsible for the overall management of the entire program, including all design authority for commissioning, maintaining, operating, refuelling and decommissioning of the reactor plants.
8. Fuel Cycle Approach
The anticipated core lifetime is more than 5 years. At the end of every fifth year of operation, the graphite fuel prismatic blocks and spent fuel will be removed from the reactor pressure vessel and will be stored for 12 months in an on-site underground fuel storage silo before being transported to a permanent repository site.
The spent fuel will be transported from the plant site to the repository site using a certified, existing fuel transfer cask. Each transfer cask will hold six graphite fuel blocks, assembled in a Fuel Cartridge and which will be replaced as one unit. StarCore will use a once-through LEU cycle initially, with plans to pursue R&D to move to a fuel recycling capability depending on political agreements. We also plan to investigate TRU use in MOX TRISO fuel to start recycling LWR waste in due course.
9. Waste Management and Disposal Plan
The plant will be decommissioned by StarCore at the end of its life, and all decommissioning cost is already built into the StarCore Financial Plan. This work will include: removal of the reactor fuel and shipment to a spent fuel storage facility; the spent fuel will be managed and disposed of; removal of the reactor vessel and shipment off site and disposed of; disposal of reactor components that cannot be reused; removal of all equipment with radioactive components at the plant site and shipment to a disposal site; demolition of all above ground facilities at the plant site and shipment of the materials off-site to a disposal facility; and entombment of the below ground facilities at the plant site by backfilling them with concrete.
10. Development Milestones
209- 2013 Preliminary studies and initial pre-conceptual design.
2013-2017 Pre-conceptual design phase, technology validation and vendor contracts and qualification 2017-2020 Fund raising and PPA contracts
2021-2016 Projected deployment (start of construction to commissioning)
MAJOR TECHNICAL PARAMETERS
Parameter Value
Technology developer, country of origin
JAEA, MHI, Toshiba/IHI, Fuji Electric, KHI, NFI, Japan
Reactor type Prismatic HTGR
Coolant/moderator Helium / graphite Thermal/electrical capacity,
MW(t)/MW(e)
<600 / 100~300 Primary circulation Forced by gas turbine NSSS Operating Pressure
(primary/secondary), MPa
7 / 7 Core Inlet/Outlet Coolant
Temperature (oC)
587-633 / 850-950 Fuel type/assembly array UO2 TRISO ceramic coated
particle Number of fuel assemblies in
core
90
Fuel enrichment (%) 14
Core Discharge Burnup (GWd/ton)
120 Refuelling Cycle (months) 48
Reactivity control mechanism Control rod insertion Approach to safety systems Active and passive
Design life (years) 60
Plant footprint (m2) ~250x250 (4-reactor plant) RPV height/diameter (m) 23 / 8
RPV weight (metric ton) ~1000
Seismic Design (SSE) >0.18g automatic shutdown Fuel cycle requirements /
Approach
Uranium once through (initially)
Distinguishing features Multiple applications of power generation, cogeneration of hydrogen, process heat, steelmaking, desalination, district heating Design status Pre-licensing basic design
completed
1. Introduction
The 300 MW(e) Gas Turbine High Temperature Reactor (GTHTR300) is a multi-purpose, inherently-safe and site-flexible small modular reactor (SMR) that Japan Atomic Energy Agency (JAEA) is developing for commercialization in 2030s. As a Generation-IV technology, the GTHTR300 offers important advances when compared to current light water reactors. The reactor coolant temperature is significantly higher in the range of 850-950oC. Such high temperature capability as proven in the JAEA’s HTTR test reactor operation enables a wide range of applications. The design employs a direct-cycle helium gas turbine to simplify the plant by eliminating water and steam systems while generating power with enhanced efficiency of 45-50%. The design incorporates ceramic fuel, low power density but high thermal conductivity graphite core, and inert helium coolant to secure inherent reactor safety. The inherent safety permits siting in close proximity to users, in particular to industries, so as to minimize cost and loss of high temperature heat transmission. Dry cooling becomes economically feasible due to high temperature (above 150oC) heat rejection from the gas turbine cycle, making inland and remote siting possible without the need of a large source of cooling water.