RUTA | POWER PLANT DESIGN
Top floor
Control rod drive
Distributing manifold Primary heat exchanger
Left, figure 1: RUTA-70 Reactor plant (cross-section)
ø 3200 ø 2150
Upper plenum Check valve Collecting manifold Pool cladding Core Support plate with control rod cluster guides
Water drainage of the 2nd circuit
Water supply of the 2nd circuit
Feasibility for district heating in Finland ● Using the RUTA-70 to provide district heat is in accord with the framework of Finnish legislation and regulations.
● Finland has experience in operating a pool-type PWR in urban environments. The FiR1 Triga Mark II research reactor was in operation in Espoo in the immediate vicinity of densely populated areas in the capital region of Finland from 1962 to 2015. During this period, rich operational experience was accumulated.
● Fortum Oy has operated Loviisa 1 and Loviisa 2 — power plants with VVER-440 reactors — since the mid-1970s. That operational experience will be important because the RUTA-70 fuel assembly was designed based on the VVER-440 fuel assembly.
● In computer modeling of the design emergency modes of RUTA-70, which assumed a halt in circulation of the coolant in the primary circuit, the temperature of the cermet fuel did not rise above 172°C. The Finnish regulatory framework (the YVL guidelines) defines a class 1 accident in cases where more than 1% of the fuel rods are damaged as a result of a heat removal crisis and the fuel element cladding temperature is above 650°C. It can be stated that, while maintaining the integrity of the fuel cladding, the fuel temperature does not reach the boundaries of the class 1 design basis accident, so the RUTA-70 reactor plant is formally accident-free.
Development options Considering seasonal fluctuations in heat consumption, the load following capacity of the RUTA-70 reactor in the range
www.neimagazine.com | October 2021 | 41
of 21-70MW is important in terms of operational efficiency. A two-unit plant will meet the power needs of consumers, even when, during the period of minimum heat demand, one unit stops and the other drops to the minimum controlled power level. The following sets of measures are proposed with the aim of licensing and construction of a pilot nuclear district heating project based on the RUTA-70. The Finnish Nuclear Power Act in Section 11 establishes the need for a Decision-in-Principle by the Finnish parliament for all nuclear facilities operated with a thermal power of more than 50MW. Changing the power rate of the RUTA reactor to a level below 50MW will make it possible to bypass the Decision-in-Principle and immediately U
Left:
Artists impression of RUTA-70
17250 12050 8750 1000
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53
