ARTICLE IMB-5000
SYSTEMS LEAKAGE MONITORING
IMB-5100 LEAKAGE DETECTORS
IMB-5110 REQUIREMENTS
(a) As part of the inservice inspection equipment
for Class 1 liquid metal systems, diverse, redundant
leak detection devices shall be installed to monitor
each component and liquid metal appurtenance of the
system to monitor for liquid metal to gas leakage.
These leak detection systems shall have sensitivities
and response times to prevent the following conditions
from occurring:
(1) substantial weakening of a component due to
corrosion resulting from small leaks;
(2) damage to other components and cells resulting
from large leaks.
Table IMB-5110-1 outlines the required minimum de-
tectable leak rates, response times, and operating condi-
tions.
(b) As part of the inservice inspection equipment
for Class 1 cover gas systems, radiation monitors shall
be installed to monitor for leakage from the radioactive
gas spaces. Performance requirements for radiation mon-
itors are shown in Table IMB-5110-2 (in the course
of preparation).
IMB-5120 OPERABILITY AND CALIBRATION
TESTS
Each leak detector system shall be designed to contain
self-monitoring provisions to detect failure or degrada-
tion of function, except for actual response to aerosol
vapors while installed. Procedures shall be established
and facilities shall be provided to calibrate the detectors
periodically as required in Appendix I for required
response to specific concentrations (e.g., radioactivity
level, sodium aerosol concentration, hydrogen level,
etc.). A number of each type of leak detector systems
shall be calibrated at each outage so that all detectors
will have been calibrated at least twice each inspection
636
interval. Each leak detector channel shall have provi-
sions for in-place calibration of the readout components.
IMB-5200 SYSTEM LEAKAGE
MONITORING AND TEST
REQUIREMENTS
IMB-5210 MONITORING REQUIREMENTS
The Class 1 system shall be monitored continuously
for leakage of liquid metal and radioactive gases.
IMB-5220 LEAKAGE TESTS
In addition, prior to nuclear operation above 5% of
rated power, subsequent to shutdown for refueling,
maintenance, or inservice inspection, the pressure of
the system shall be raised such that the pressure in all
points of the system is not less than that seen at 100%
of full power operation. The data from each leakage
monitor shall be collected and evaluated for a period
sufficiently long to detect any trend prior to nuclear
operation.
IMB-5230 TEMPERATURE
All leakage tests of Class 1 systems required by
IMB-5220 shall be conducted while the liquid metal
is at a temperature of 600°F or above.
IMB-5240 LIMITATIONS
The system pressure shall be increased to the level
of the test pressure and test temperature at a rate in
accordance with the limitations specified for the system.
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