ML20107K546
| ML20107K546 | |
| Person / Time | |
|---|---|
| Site: | University of Texas at Austin |
| Issue date: | 04/16/1996 |
| From: | TEXAS, UNIV. OF, AUSTIN, TX |
| To: | |
| Shared Package | |
| ML20107K527 | List: |
| References | |
| NUDOCS 9604260201 | |
| Download: ML20107K546 (4) | |
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Technical Specificationn
' Revision 1
- 1.19 Reactor Shutdown The. reactor is shutdown if it is suberitical by at least one dollar in the reference core condition -with the reactivity of all installed 1
experiments included.
1.20 Reference Core Condition The condition of the core when it is at ambient temperature (cold) and the reactivity worth of xenon is negligible (<.30 dollars).
1.21 Research Reactor A ramearch reactor is defined as a device designed to support a self-sust.aining neutron chain reaction for research, development, educational, training, or experimental purposes, and which may have provisions for the production of radioisotopes, 1.22 Rod,-Control:
A control rod is a device fabricated from neutron absorbing material or fuel which is used to establish neutron flux changes and to compensate for routine reactivity loses.
A control rod may be coupled to its drive unit allowing it to perform a safety function when the coupling is disengaged.
1.22.1 Shim Rod A shim rod is a control rod with an electric motor drive that does not 4
perform a special function such as automatic control or pulse control.
t The shim rod shall have scram capability.
1.22.2 Regulating Rod A regulating rod is a control rod used to maintain an intended power level and may be varied manually or by a servo-controller.
The regulating rod shall have scram capability.
1.22.3 Standard Rod The regulating and shim rods are standard control rods.
1.22.4-Transient Rod b
A transient. rod is a control rod used to initiate a power pulse that 1
is operated by a motor drive and/or air pressure.
The transient rod shall have scram capability.
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12/90~
Amended 4/96 Page 9
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Revision 1 Technical Spscifications 2.
2 3.2 Reactor Control -and Safety System 3.2.1 Contro1' Assemblies 1
]
Specification (s)
'The reactor shall not beooperated unless the control rods are operable, and
- a. Control rods shall not be operable if damage is apparent to the rod or drive assemblies.
b', The scram time measured from the instant a. simulated signal reaches the value of a limiting safety system setting to the ir.stant that the slowest scrammable control rod reaches its fully inserted position shall not exceed 1 second.
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- c. Maximum reactivity insertion rate of a standard control rod shall be less than 0.2% Ak/k per second.
3.2.2 Reactor Control System J
Specification (s)
The reactor shall'not be operable unless the minimum safety interlocks are operable.
The following control system safety interlocks shall be operable:
Control Rod Drive Number Effective Mode
- Interlock Function Operable Control Rod M
A S
P
- a. Startup Withdrawal -
3 Standard rods X
X prevent rod up movement 1
Transient rod
.X X
if startup signal is less than 2 counts per second
- b. Simultaneous Withdrawal -
3 Standard rods X
prevent rod up movement 2
Shim rods X
for two or more rods 1
Transient rod X
X
- c. Non pulse condition -
1 Transient rod X
X prevent air actuation if rod drive is not down
'd. Pulse Withdrawal -
3 Standard rods X
X prevent withdrawal of
.non pulse rods
- e. Transient Withdrawal -
1 Transient rod X
X prevent air actuation if linear power is more than 1 kilowatt
- Modes-are:.(M) Manual, (A) Auto, (S) Square Wave, and (P) Puise l
12/90 : Amended 4/96 Page 14
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Revision 1 Technical Specifications 1
3'2.3 Reactor Safety System Specification (s)
The reactor shall not be operable unless the minimum safety channels are operable.
The following control rod scram safety channels shall be operable.
Safety-System Number Effective Mode
- Function Operable Safety Channel M. A. S P
- a. Scram at $550'C' 2
Fuel Temperature X
X
- b. Scram at $1.1 Mw 2
Power Level X
Scram at $2000Mw 1
Pulse Power X
- c. Scram on loss 2
Migh Voltage X
X
- d. Scram on loss 1
Magnet Current X
X
- e. Scram on demand 1
X Console Button
- f. Scram on loss of 2
Watchdog Trip timer reset Microprocessor scan rate X
X
- Modes are: (M) Manual, (A) Auto, (S) Square Wave, and (P) Pulse 3.2.4 Reactor Instrument System Specification (s)-
A minimum configuration of measuring channels shall be operable.
The following minimum reactor parameter measuring channels shall be operable:
Instrument System Number Effective Mode
- Function Operable Measurine Channel M.A.
S P
- a. Temperature 2
Fuel Temperature X
X
- b. Power 2
Power Level X
- c. Pulse 1
Pulse Power X
- d. Pulse' 1-Pulse Energy X
- Modes are: (M) Manual, (A) Auto, (S) Square Wave, and (P) Pulse l
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12/90 Amended 4/96 Page 15
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Revision 1 Technical Specificatiens e-Interlocks applicable to the transient rod determine the proper rod operation during manual mode and pulse mode operation. ~ The non pulse condition interlock determines the allowable position of the rod drive for actuation of the FIRE switch. Actuation of the switch applies the air impulse for removal of the transient rod from the reactor core.
Auto modo applies the same interlock controls as the manuel mode to the shim and transient rods.
Servo calculations limit reactivity insertions by controlling regulating rod drive speed. one limit, a reactor period of four decades per minute, restricts simultaneous up motion of the regulating rod with any other rod.
i Two basic interlocks control' rod movements for the pulse mode.
The interlock to prevent withdrawal of the motor driven rods in the pulse mode is designed to prevent changing the critical state of the t eactor prior to the pulse.
A power level interlock controls potential fuel temperature changes by setting a limit of less than 1 kilowatt for initiation of any pulse.
i 8quare wave mode appites the same interlock controls as the pulse mode to all control rods. A a
pulse transient terminates the node by changing to auto or manual mode. The change to auto or to manual mode becomes effective when a preset condition (demand power) occurs or a preset time (ten seconds) expires.
A.3.2.3 Reactor Safety System Applicability These specifications apply to operation of the reactor safety system.
Obj ective i
The objective is to determine the minimum safety system scrams operable for the operation of the reactor.
Bases Safety system scram functions consist of three types. These scram types are the limiting safety system settings,. operable system conditions, and the manual or program logic scrams.
The scrams cause control rod insertion and reactor shutdown.
Scrams for limiting safety system settings - consist of signal trip 1cvels that monitor fuel temperature and power level.
The trip levels are conservative by a significant margin relative to the fuel element temperature safety limit.
Operation without adequate control and safety system power supplies is prevented by scrams on neutron detector high voltage and control rod magnet current.
Manual action of-the scram switch, key. switch, or computer actuation of watchdog timers will initiate a protective action of the ' reactor safety system.
Either of two watchdog circuits provide updating timers to terminate operation in the event that key digital
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processing routines fail, such as a display system.
Each watchdog circuit with four resettable timers contains one trip relay and monitors one microcomputer.
12/90 Amended 4/96 Page 44 I
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