Overview of ageing and degradation issues in light water reactors (LWRs) - Materials' Ageing and Degradation in Light Water Reactors - page 341

(a)

Containment structure

S tea m line

Con t r ol rods

Generator

Steam
generator

Reactor
vessel

Pump

Turbine

Reactor

Cooling
tower

Condensor
cooling
water

Pump

(b)

Containment
cooling system

4

Steam line

Reactor vessel

Turbine
generator

Separators
& dryers

Heater

Condenser
Condensate
pumps

Feedwater

3

C ore

1 & 2

Feed
pumps

Control
rods

Demineralizer

Recirculation pumps

￿ ￿ ￿ ￿ ￿ ￿

Emergency water
supply systems

1. 1 Schematics of (a) PWR (www.aboutnuclear.org) and (b) BWR
(www.nrc.gov/reactors/bwrs.html).

containing either B 4 C or AgInCd are inserted from the top in PWRs. While
the PWRs contain about the same weight of fuel and cladding as BWRs, the
number of assemblies is one third of that in the BWRs since the number
of rods per assembly is greater in the former (17 8 in

BWRs - these numbers vary slightly depending on the vendor and the gen-
eration type). Table 1.1 summarizes the important characteristics of these
reactors that include Russian VVER and RBMK.
As outlined earlier and presented in Fig. 1.1a and 1.1b, different materi-
als are selected for the manufacture of various components and the selection

× 17 in PWRs vs 8 ×