Browns Ferry Nuclear Plant Nuclear Power Plant Orientation
Introduction to BWR Systems Slide 2 TVAN Technical Training Health
Physics (RADCON) Initial Training Program HPT001.014D Rev. 0 Page 2
of 34 Introduction During this phase of the training we will
discuss the basic operation of a Boiling Water Reactor (BWR) Plant,
including: the major design concepts of the Browns Ferry BWR-4 and
its Mark I containment the importance of nuclear safety. We will
also discuss several of the systems associated with BFNs operation.
TP-2 Slide 3 TVAN Technical Training Health Physics (RADCON)
Initial Training Program HPT001.014D Rev. 0 Page 3 of 34 Enabling
Objectives Identify the major components and flowpaths in the steam
cycle. Recognize the functions of water in a BWR Recognize the
functions of the control rods in a BWR Recognize the capability and
purpose of nuclear instrumentation TP-3 Slide 4 TVAN Technical
Training Health Physics (RADCON) Initial Training Program
HPT001.014D Rev. 0 Page 4 of 34 Enabling Objectives Identify
alternate sources of emergency cooling water to the reactor vessel
Relate major concepts employed in containment design Identify
inherent safety features of a BWR Compare advantages and
disadvantages of a BWR to that of a PWR TP-4 Slide 5 $ Tennessee
River HPT001.014D Rev. 0 Page 5 of 34 HPT001.014D Rev. 0 Page 5 of
34 Slide 6 TVAN Technical Training Health Physics (RADCON) Initial
Training Program HPT001.014D Rev. 0 Page 6 of 34 BWR Design
Selected by GE due to its inherent advantages in control and design
simplicity. Single loop system; steam and associated secondary
systems are radioactive. Operating pressure is approximately half
that of a PWR at 1,000 psi. Capacity of units two and three is
~1,100 Mwe each. TP-6 Slide 7 TVAN Technical Training Health
Physics (RADCON) Initial Training Program HPT001.014D Rev. 0 Page 7
of 34 BWR Internal Flow Feedwater enters downcomer. Recirculation
loops provide forced circulation. Moisture removed by separators
and dryers. Steam exits steam dome. TP-7 Slide 8 BWR Internal Flow
Core 8 HPT001.014D Rev. 0 Page 8 of 34 Slide 9 Recirculation System
Flow Path Recirc Pump Suction Recirc Pump Motor Ring Header Risers
Jet Pump 9 HPT001.014D Rev. 0 Page 9 of 34 Slide 10 Steam Dryer
installed in Reactor Pressure Vessel 10 HPT001.014D Rev. 0 Page 10
of 34 Slide 11 Steam Dryer stored in Equipment Pit 11 HPT001.014D
Rev. 0 Page 11 of 34 Slide 12 Fuel Transfer Canal 12 HPT001.014D
Rev. 0 Page 12 of 34 Slide 13 TVAN Technical Training Health
Physics (RADCON) Initial Training Program HPT001.014D Rev. 0 Page
13 of 34 Plant Layout The entire Reactor Coolant System (RCS) and
other primary support systems are located within containment (the
drywell) and reactor buildings. TP-13 l Main Steam, Condensate and
Feedwater (all radioactive) are housed within the turbine building.
l The reactor is operated remotely from the control building. Slide
14 TVAN Technical Training Health Physics (RADCON) Initial Training
Program HPT001.014D Rev. 0 Page 14 of 34 Main Steam System Steam
generated by the reactor is admitted to four main steam lines. One
high pressure and three low pressure turbines convert thermody-
namic energy into mechanical energy to drive the main generator.
Safety objective is to prevent overpressurization of the nuclear
system. TP-14 Slide 15 Main Steam System Flow Path To HP and LP
Turbines RPV 15 HPT001.014D Rev. 0 Page 15 of 34 Slide 16 TVAN
Technical Training Health Physics (RADCON) Initial Training Program
HPT001.014D Rev. 0 Page 16 of 34 Condensate and Feedwater Systems
Once the steam has passed through the high and low pressure
turbines, it must be condensed and then pumped back to the reactor
so that the cycle can be repeated. These systems will collect,
pre-heat, and purify feedwater prior to its return to the reactor
plant. TP-16 Slide 17 Condensate System Flow Path A BC LP FW
Heaters B C A A B C 17 HPT001.014D Rev. 0 Page 17 of 34 Slide 18
Feedwater System Flow Path Reactor Feed Pumps HP FW Heaters Primary
Containment Reactor Pressure Vessel RPV 18 HPT001.014D Rev. 0 Page
18 of 34 Slide 19 TVAN Technical Training Health Physics (RADCON)
Initial Training Program HPT001.014D Rev. 0 Page 19 of 34 Fuel Cell
Currently, Framatome is the supplier of fuel for BFN. Four fuel
bundles per cell. 764 bundles per reactor. TP-19 Slide 20 Fuel Cell
Control Rod Blade 20 HPT001.014D Rev. 0 Page 20 of 34 Slide 21 TVAN
Technical Training Health Physics (RADCON) Initial Training Program
HPT001.014D Rev. 0 Page 21 of 34 Control Rods Rods contain boron as
the neutron absorber. Tubes held in cruciform array by a stainless
steel sheath. 185 control rods per reactor. TP-21 Slide 22 Control
Rod Blade 22 HPT001.014D Rev. 0 Page 22 of 34 Slide 23 Control Rod
Blades 23 HPT001.014D Rev. 0 Page 23 of 34 Slide 24 TVAN Technical
Training Health Physics (RADCON) Initial Training Program
HPT001.014D Rev. 0 Page 24 of 34 Nuclear Instrumentation Source
range - 0.1 to 10 6 cps Intermediate range - 10 4 cps to 40% power.
Power range - 1 to 125% power. TP-24 Three ranges of neutron
monitoring; all in-core. Slide 25 Nuclear Instrumentation IN-CORE
HOUSING GUIDE TUBE CORE SUPPORT REACTOR SUPPORT STRUCTURE LENGTH OF
ACTIVE FUEL DETECTOR CHAMBERS BOTTOM OF TOP GUIDE REACTOR VESSEL 25
HPT001.014D Rev. 0 Page 25 of 34 Slide 26 TVAN Technical Training
Health Physics (RADCON) Initial Training Program HPT001.014D Rev. 0
Page 26 of 34 EMERGENCY CORE COOLING SYSTEMS (ECCS) Prevent fuel
cladding fragmentation for any failure including a design basis
accident. Independent, automatically actuated cooling systems.
Function with or without off-site power. Protection provided for
extended time periods. TP-26 Slide 27 TVAN Technical Training
Health Physics (RADCON) Initial Training Program HPT001.014D Rev. 0
Page 27 of 34 EMERGENCY CORE COOLING SYSTEMS (ECCS) High Pressure
Coolant Injection (HPCI) Low Pressure Coolant Injection (LPCI) Core
Spray Automatic Depressurization System TP-27 Slide 28 Condensate
Storage Tanks ~2,000,000 gal Torus ~950,000 gal Reactor Tennessee
River Normal Systems CONDENSATE FEEDWATER CONTROL ROD DRIVE
Emergency Systems HIGH PRESSURE COOLANT INJECTION CORE SPRAY LOW
PRESSURE COOLANT INJECTION RHR SVC WATER FIRE PROTECTION 28
HPT001.014D Rev. 0 Page 28 of 34 Emergency Core Cooling Water
Sources Slide 29 TVAN Technical Training Health Physics (RADCON)
Initial Training Program HPT001.014D Rev. 0 Page 29 of 34 Primary
and Secondary Containment Primary Containment consists of the
Drywell and Suppression Pool (Torus). Secondary Containment
consists of the Reactor Building. Designed to contain the energy
and prevent significant fission product release in the event of a
loss of coolant accident. TP-29 Slide 30 TVAN Technical Training
Health Physics (RADCON) Initial Training Program HPT001.014D Rev. 0
Page 30 of 34 Containment Design Structural Strength - steel
structure with reinforced concrete able to withstand internal
pressure. Pressure Suppression - large pool of water in position to
condense steam released from LOCA. Designed to contain the energy
and prevent significant fission product release in the event of a
loss of coolant accident. TP-30 Slide 31 Primary and Secondary
Containment Drywell Torus 31 HPT001.014D Rev. 0 Page 31 of 34 Slide
32 TVAN Technical Training Health Physics (RADCON) Initial Training
Program HPT001.014D Rev. 0 Page 32 of 34 Advantages of BWRs Single
loop eliminates steam generator Bottom entry control rods reduce
refueling outage time/cost; also provide adequate shutdown margin
during refueling. Lower operating pressure lowers cost to obtain
safety margin against piping rupture. Design simplifies accident
response. TP-32 Slide 33 TVAN Technical Training Health Physics
(RADCON) Initial Training Program HPT001.014D Rev. 0 Page 33 of 34
Disadvantages of BWRs More radiation/contamination areas; increased
cost associated with radwaste. Piping susceptible to intergranular
stress corrosion cracking (IGSCC). Off-gas issues (e.g. - H 2 gas
presents explosion potential, low levels of radioactive noble gases
are continuously released). TP-33 Slide 34 TVAN Technical Training
Health Physics (RADCON) Initial Training Program HPT001.014D Rev. 0
Page 34 of 34 Summary A Boiling Water Reactor plant is comprised of
many different and complex systems, all of which support the
overall goal of safely producing electricity. The design challenge
of a BWR is to incorporate all the criteria of power generation and
safety in non-conflicting ways in order to meet the load demand of
the public and satisfy the requirements set forth by the Nuclear
Regulatory Commission (NRC). TP-34
