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Description / Abstract:
OBJECT AND SCOPE
The purpose of this Code is to establish procedures for conducting
tests to determine the thermal
performance of a nuclear steam supply system as a unit. These tests
include capacity, reactor power
level, efficiency, and other related operating characteristics such a
s steam pressure, moisture
content, and solids in the steam. (See Section 4.)
A determination of any or all of the performance items specified above
may be necessary for
purposes such as:
Checking the actual performance against guarantee.
Comparing these items with some standard of performance.
Comparing performance at different operating conditions.
Checking performance after new reactor fuel is loaded.
Determining the effects of changes to equipment.
Periodic verification of the means employed to monitor reactor power
level.
The rules and instructions given in this Code apply to the equipment
defined in the introduction.
Testing of auxiliary apparatus shall be governed by the Performance
Test Code applying specifically
to the auxiliary apparatus in question.
Since there is no accurate, direct method of measuring the energy
released by the nuclear fuel, the
only method used for calculating the energy balance is the direct
measurement of the energy output,
losses and credits. This is referred to hereinafter as the energy loss
method.
The output is defined as the energy absorbed by the working fluid or
fluids within the envelope
boundary, The working fluid is the steam and water substance through
which means the nuclear steam
supply system delivers energy.
The input is defined as the energy released by the nuclear fuel plus
energy credits added to the
working fluid or fluids, air, gas, and other fluid circuits that cross
the envelope boundary, as
shown in Figure for pressurized water reactors (PWR) and in Figure 3
for boiling water reactors
(BWR). The envelope boundary encompasses the equipment to be included
in the designation "nuclear
steam supply system." The input is equal to the output plus losses.
Energy credits are defined as those amounts of energy added to the
envelope of the nuclear steam
supply system other than the nuclear energy released by the fuel.
These credits include quantities
such as pumping energy.
Losses are defined as energy lost from the envelope of the nuclear
steam supply system.
For a better understanding of the relationships between input, output,
credits, and losses, refer
to Figures 2 (PWR) or 4 (BWR).
The capacity of a nuclear steam supply system is defined as the actual
evaporation rate of steam in
pounds per hour delivered at specified conditions of the working
fluid.
The reactor power level is defined as the rate of energy release in
the reactor core in units of
megawatts.
The efficiency of a nuclear steam supply system, as determined within
the scope of this Code, is
defined as the ratio of energy absorbed by the working fluid or fluids
to energy input as defined
in Par. 1.04.2. This definition disregards the energy supplied to the
auxiliary apparatus external
to the envelope. (See Figures 1 and 3.)
Efficiency is expressed by the following equation:
The determination of data of a research nature or other special data
is not covered by this Code.
It is recommended that a report be prepared for each test, giving
complete details of the
conditions under which the test has been made, including a record of
test procedures and all data
in a form suitable for demonstrating that the objectives of the test
have been attained.