ML20127D714
| ML20127D714 | |
| Person / Time | |
|---|---|
| Site: | University of Illinois |
| Issue date: | 01/11/1993 |
| From: | ILLINOIS, UNIV. OF, URBANA, IL |
| To: | |
| Shared Package | |
| ML20127D711 | List: |
| References | |
| NUDOCS 9301190018 | |
| Download: ML20127D714 (1) | |
Text
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- Startup Count Rate i Prevent control Reactor Startup Rod withdrawal when neutron count rate is less then 1 por second Standard Control Rod i Prevent withdrawal of a Steady-state Position transient rod when the Mode standard control rods are not fully inserted. (This does not apply to the adjustable transient rod if the movable cylinder is fully inserted when the air pressure is applied.)
Dases The interlocks which prevent the withdrawal of the transient rods in the steady '
state mode or if the power level is greater than 250 kw prevent inadvertent pulses which might cause the fuel temperature to exceed the safety limit. The interlock to prevent startup of the reactor with less than one neutron per second indicated on the startup channel assures that sufficient neutrons are available to assure proper operation of the startup channel.
The fuel temperature scrams provide the protection to assure that if a condition results in which the limiting safety system setting is exceeded, an immediate shutdown will occur to keep the fuel temperature below the safety limit. The power level scrams are provided in all modes of operation as added protection against abnormally high fuel temperatures and-to-assure-that-the-reseter operat4en-stays-with4n-the-44eensed-44mits such that the reactor will scram before a safety limit is exceeded as discussed in the Safety Analysis Report.
The manual scram allows the operator to shutdown the system if an unsafe or abnormal condition occurs.
The specifications on the reactor tank water level are included as safety measures in the event of a serious loss of primary system water. The tank water level criterion assures that reactor operations are terminated when a major leak occurs in the primary system. The spray system assures removal of.the decay heat from the fuel elements if the water level in the tank drops below the top grid plate. The analysis in Section VI of_the SAR shows that no fuel damage would occur under these conditions.
The watchdog scram ensures that adequate communications between the Data Acquisition Computer (DAC) and the Control System Computer (CSC) units.
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