Pump
up the nuclear power!
PD
Sharma, AB Ghare and Vijay Misri share the experience of the Nuclear
Power Corporation of India in choosing pumps for critical applications
Pumps
and valves are considered as the lifeline of any industrial activity.
They are vital elements in several fluid handling applications and are
used in all industries from the simplest to the most critical applications.
Nuclear power plants are no exception in this regard.
Typically, a twin unit nuclear power plant uses several hundred pumps
and valves. The pumping equipment of a nuclear power plant uses power
inputs ranging from a few KW to about 6,000 KW, while the valve sizes
range from 15 mm NB (narrow band) to 2,000 mm NB. The performance requirements
for pumps and valves of nuclear plants have to be as stringent as other
critical services. In addition, these valves and pumps have to be even
more reliable and capable of continuous and unattended operation, even
under adverse conditions. In other words, they have to meet stringent
standards for leak tightness, use of radiation and corrosion-resistant
materials and
seismic qualification.
The field performance of pumps and valves in operating plants is governed
by several factors before installation and after commissioning.
The process encompasses the whole cycle, right from identification of
potential sources, techno-commercial source evaluation, product manufacture
and quality control, to proper maintenance and condition monitoring.
Adhering to this process, The Indian Nuclear Power Programme of the
Nuclear Power Corporation of India Limited (NPCIL), Mumbai, set up 2
x 210 MW reactors at Tarapur on a turnkey basis in 1969, after which
NPCIL added 12 units of Pressurised Heavy Water Reactors (PHWR).
Pumping equipment
The pumping equipment required for two units of a typical 540 MW
PHWR is listed in Table 1. The most critical pumping applications in
a nuclear power plant include the primary coolant pump, the shut down
cooling pump, the pressurising pump, the main boiler feed pump and the
condenser cooling water pump.
Primary coolant pump
Primary coolant pumps (PCPs) are vertical, single stage radial
impeller, double volute casing centrifugal pumps.
PCPs of Pressurised Water Reactors (PWR) and PHWR are employed for circulating
radioactive, pressurised hot water in a circuit consisting of a reactor,
known as heat source, and a steam generator , termed as a heat sink.
The pressure-retaining components of PCPs are designed and ...
