ML20055G037

Proposed Replacement Pages for Tech Specs,Correcting Typo in Section 3.2.2

ML20055G037
Person / Time
Site:	Armed Forces Radiobiology Research Institute
Issue date:	07/13/1990
From:	ARMED FORCES RADIOBIOLOGICAL RESEARCH INSTITUTE
To:
Shared Package
ML20055G036	List: ML20055G035 ML20055G037
References
NUDOCS 9007200079
Download: ML20055G037 (3)

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D ATTACHMENT 2 Proposed Replacement Pages for the i

Technical Specifications f

for the AFRRI Reactor Faciliev 4

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Armed Forces Radiobiology Research Institute Bethedsa, MD 20814-5145 July 1990 i

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9007200079 900713 PDR ADOCK 05000170 R PDC

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. tions on reactor power level indication are included in this Section, since ths

~* _ power level is related to the fuel temperature.

3.2.2 REACTOR SAFETY SYSTEMS Aoolicability This specification applies to the reactor safety system.

Objective The -objective is to specify the minimum number of rosetor safety system channels that must be operable for safe operation.

Sticeification The reactor shall not be operated unless the safety systems described in Tables 2 and 3 are operable.

TABLE 2. MINIhiUM REACTOR SAFETY SYSTEM SCRAMS Maximum Minimum Number in Mode Channel Set Point Steady State Pulse Fuel Temperature 600'C 2 2 Percent Power, Iligh Flux 1.1 MW 2 0 Console Manual Scram Bar Closure switches 1 1 liigh Voltage Loss to Safety Channels 20% loss 2 1 Pulse Time 15 seconds 0 1 Emergency Stop (1~ each exposure room, 1 on console) Closure switch 1 1 Pool Water Level 14 feet from top of core 1 1 Watchdog (DAC to CSC) On digital console 1 1 i

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The fuel temperature and power level scrams provide protection to assure that the reactor can be shut down before the safety limit on the fuel element temperature will be exceeded The manual scram allows the operator to shut down the system at any time if an unsafe or abnormal condition occurs. In the l event of failure of the power supply for the safety channels, operation of the reactor > without adequate instrumentation is prevented. The preset timer insures that the reactor power level will reduce to a low level after pulsing. The emergency stop allows personnel trapped in a potentially hasardous exposure 10

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room or the reactor operator to stop actions through the interlock system. The /

,  : pool water level insures that a loss of biological shielding would result in a reactor shutdown. The watchdog scram will insure adequate communication y between the Data Acquisition Computer (DAC) and the Control System Computer (CSC) units. ,

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, TABLE 3. MINIMUM REACTOR SAFETY SYSTEM INTERLOCKS

' i' Effective Mode ,

Action Prevented Steady State Pulse Pulse initiation at power levels greater X than 1 kilowatt Withdrawal of any control rod expect transient X Any rod withdrawal with count rate in X X operational channel below 0.5 cps Simultaneous manual withdrawal of two X standard rods -

Basis l!

The interlock preventing the initiation of a pulse at a critical level above 1 kilowatt' assures that the pulse magnitude will not allow the fuel element :

temperature to approach the safety limit. The interlock that prevents movement of standard control rods in pulse mode will prevent the inadvertent placing of -

the reactor on a positive period while in pulse mode. Requiring a count rate to  ;

be seen by the operational channels insures sufficient source neutrons to bring the reactor critical under controlled conditions. The interlock that prevents the simultaneous manual withdrawal of two standard control rods limits the amount l

of reactivity added per unit time.

3.2.3 FACILITY INTERLOCK SYSTEM .

Applicability This specification applies to the interlocks that prevent the accidental exposure of an individual in either exposure room.

Objective The objective is to provide sufficient warning and interlocks to prevent movement of the reactor core to the exposure room in which someone may be working, or prevent the inadvertent movement of the core into the lead shield doors.

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