ML20033F288
| ML20033F288 | |
| Person / Time | |
|---|---|
| Site: | 05000199 |
| Issue date: | 03/12/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20033F281 | List: |
| References | |
| R-094-A-008, R-94-A-8, NUDOCS 9003190283 | |
| Download: ML20033F288 (8) | |
Text
_._.
~
ATTACHMENT TO LICENSE AMENDMENT NO. 8 TO FACILITY OPERATING LICENSE NO. R-94 DOCKET NO. 50-199 Replace the following pages of the Appendix A Technical Specifications with the attached pages. The revised pages are identified by amendment number and
-contain vertical lines indicating the areas of change.
Remove Insert 1-1 1-1 1-2 1 2-1 2-1 2-2 2-2 3-1 3-1 3-2 3-2 5-3 5-3 L
l pp AO O
9 P
~**
~
l '. 0 DEFINITIONS The terms Safety Limit, Limiting Safety System Setting, and Limiting Condition for Operation are as defined in paragraph 50.36 of 10 CFR Part 50.
ALARA ALARA is a concept introduced by the Nuclear Regulatory Consnission IRET to all reactor facilities. The basis of ALARA is that all exposure to radiation should be kept "as low as reasonably achievable" (ALARA).
channel
- A channel is the combination of sensor, line, amplifier and output devices which are connected for the purpose of measuring the value of a parameter.
channel calibration A channel calibration is an adjustment of the channel such that.its output corresponds with acceptable accuracy to known values of the. parameter which the channel measures. Calibration shall encompass the entire channel, including equipment actuation, alarm, or trip and shall be deemed to include a channel test.
channel check A channel check is a qualitative verification of acceptable performance liy observation of channel behavior. This verification, where possible, shall include comparison of the cl.annel with other independent channels or systems measuring the same variable.
channel' test - A channel test is the introduction of a signal into the channel for verification that it is operable, control rod Plates fabricated with neutron. absorbing material used to establish neutron flux changes and to compensate for routine reactivity losses.
This includes safety-type and regulating rods.
core The portion of the reactor volume which includes the fuel elements, the source, and the' control rods.
delayed neutron fraction When converting between absolute - and dollar-value reactivity units, a beta effective delayed neutron fraction of 0.0078 is used.
drop time The elapsed time between reaching the complete removal setpoint and the full insertion of a safety-type rod.
excess reactivity Excess reactivity is that amount of reactivity that would exist if all control rods (control, regulating) were moved to the maximum reactive condition from the point where the reactor is exactly critical (K,ff=1).
i 1-1 Amendment No. 8 n.
r
.+.
Any object, other than a fuel element or handling tool, which experiment is inserted into the volume formed by projecting the grid plate vertically to the tank pool water surface is to be regarded as an experiment in the core.
The measured value is the value of a parameter as it' appears measured value on the output of a channel, movable experiment An experiment where it is intended that part of or the entire experiment may be moved in or near the core or into and out of the reactor pool water.
operable Operable means a component or system is capable of performing its intended function.
operating Operating means a component or system is performing its intended function.
reactivity limits The reactivity limits are those limits imposed on reactor core excess reactivity.
reactivity worth of an experiment The reactivity worth of an experire.nt is the maximum aosolute value of 'the reactivity change that would occur as a result of intended or anticipated changes or credible malfunctions that alter experiment position or configuration.
reactor operating The reactor is operating whenever it is not secured or
- shutdown, (RO) - An individual who is licensed to manipulate the reactor operator controls of a reactor.
reactor safety systems Reactor safety systems are those systems, ' including their associated input channels, which are designed to initiate automatic reactor protection or to provide information for initiation of manual protective-
- action, reactor secured A reactor is secured when:
1)
It contains insufficient fissile material or moderator present in the reactor, adjacent experiments or control rods, to attain criticality under optimum availabic conditions of moderation and reflection, or g
______i s
2.0 SAFETY LIMITS AND LIMITING SAFETY SYSTEM SETTINGS 2.1 Safety Limits 2.1.1 Applicability This specification applies to the melting temperature of the fuel cladding.
2.1.2 Objective To assure that the integrity of the fuel is maintained.
2.1.3 Specifications The safety liinit shall be on the tenperature of the fuel element cladding, which shall be less than 1080*F.
2.1.4 Bases.
The melting temperature of'the aluminum used as cladding on the fuel elements is 1080 F.
Therefore, in order to maintain fuel element integrity, the cladding temperature must not exceed 1080'F. As reported in Section 6.1.2 of " Analyses for Conversion of the Manhattan College Zero Power Reactor from HEU to LEU Fuel" by J. Matos,)and K. Freese of Argonne National Laboratory (ANL)
(Reference 1. The maximum cladding temperature that can ever be reached is only 239'F (115'C) and reaches this level only during the Maximum Hypothetical Accident. The specification, therefore, provides assurance on the integrity of the fuel within the cladding.
2-1 Amendment No. 8
~
2.2 LimitingSafetySystemSettings(LSSS) 2.2.1 Applicability This specification applies to the setpoints of safety channels which monitor reactor power level.
2.2.2 Objective To assure that automatic trip action is initiated and that the L
operator is warned to take protective action against exceeding l~
a safety limit.
2.2.3 Specifications r
The limiting safety system setting shall be on reactor. maximum power level not exceeding 0.125 watt, or 125% of full power.
2.2.4 Bases Since there is no forced circulation cooling, the. reactor-core is cooled by the water surrounding the reactor core. Therefore, the only parameter which could be used as a limit for the fuel cladding temperature is the reactor power. The analysis in Reference 1 (see Section I.1.4 of TS) shows that even for the Maximum Hypothetical Accioent (a reactor power excursion of 183 kilowatts), the maximum cladding temperature reaches only 239'F(115'C).. This temperature is m ch lower than the tempera-ture-(1080'F) at which cladding damage could occur. Therefore, a large safety margin exists between the safety system set point and the cladding safety limit.
2-2 Amendment No. 8
j J
3.0 LIMITING COND'
'R OPERATION j
3.1 Rea e Parameters i
- 3.1.1_
Applicattlity These specifications apply to the parameters which describe the reactivity condition of the core, 3.1.2 Objective e
To ensure that the reactor cannot achieve prompt criticality and that it can be safely shut down under.any condition.
3.1.3 Specifications The reactor'shall not be made critical unless the following conditions exist:
A.
The total core excess reactivity with or withovt the movable experiments of section 3.8.3 shall not exceed 0.44%A k/k (0.56$) at any condition of the reactor.
B.
The minimum shutdown margin provided by control rods shall not be less than 0.46% Sk/k (0.59$) at any condition of the reactor.
C.
Any change in the experimental apparatus shall be approved by the' Reactor Operations Comittee.
3.1.4 Bases Specification A is based upon the previous excess reactivity of the HEU fuel and is well below 1.0$ of excess reactivity, wtich precludes prompt transients.
Specification B assures that the reactor can be shutdown from any operating condition even if the highest worth control rod should remain in the fully withdrawn position.
Specification C limits the changes in the experimental apparatus to those approved by the Committee charged wiih review and approval of experiments.
3-1 Amendment No. 8
~-
3.2 Reactor Control and Safety System 3.2.1 Applicability These specifications apply to the reactor safety sys'*m and safety-related instrumentation.
3.2.2 Objectives To specify the lowest acceptable level of perforr.iance or the minimum number of acceptable components for the reactor safety system and safety-related instrumentation.
3.2.3 Specifications The reactor shall not be operated unless the following conditions exist:
A.
The reactor safety system shall be operable in accordance with Table 3-1.
4 B.
There shall be two safety-type control rods:
A regulating rod with a negative worth of sn 0.9% d66 k/k (1.15$)
and a shim rod with negative worth of'2:2.50% sosk/k (3.21$).
C.
The drop time for either safety rod shall not exceed 1.0 second.
D.
The reactivity insertion rate for a single rod shall not exceed 0.10%zos k/k (.128%) per second.
3.2.4 Bases Specification A provides assurance that the reactor safety system-which may be needed to shut down the reactor is operable. Each feature of the system is described in Table 3-1.
A scram system is provided that.causes interruption of the magnet current to the electromagnets, should a scram trip be exceeded.
The control rods then fall into the reactor core under the force of gravity. This system provides a conservative response to an instrumentation system failure, electric power failure, low water level, high neutron flux, and high gamma activity.
3-2 Amendment No. 8
.. J.
5.3-Reactor. Core, Fuel, Control Rods, and Startup Source 5.3.1 Reactor Core A grid plate stand is welded to the bottom of the reactor tank.
Bolted to the grid plate stand is a grid plate.
Fuel element hold-down rods are passed axially through the center of the fuel elements to hold the latter rigidly in position. These hold-down rods, each with total length of 35 inches, tre threaded into the grid plate. The shaft of these hold-down rods are made partly of aluminum and partly of lucite. The lucite portion, which consists of a solid rod one inch in diameter, is 24 inches long.
The lower portion of the hold-down rod is made out of aluminum tubing having a wall thickness of 1/3 inch and total length of 5-1/2 inches. The bottom 1-1/2 inches is threaded and secures the hold-down rodoto the grid plate. The broad top of the hold-down rod, which extends over the top of the fuel element is also made of aluminum with thickness of 3/8 inch. The aluminum portions of the hold-down rod are securely fastened to the lucite by alumirum pins and epoxy cenent.
5.3.2 Reactor Fuel The fuel portion of.the elements consists of six concentric qylinders formed by mechanically joining and pesitioning eighteen curved fuel plates within grooves cf three sp
-r g
L' webs. The cylindrical fuel plate consists of. 0.020 inch-thick uf Si, - Al fuel meat containing uranium enriched to less than 20% ih U-235 and clad on both sides with 0.015 inch of aluminum, making the total fuel plate thickness 0.05 inch. The nomir.a1 U-235 content of each full fuel element is 235 grams. The inner diameter of the innermost cylinder is about 1.25 inches and the spacing between adjacent cylinders (water channel width) is 0.118 inch.
l I
5-3 Amendment No. 8 i
m.
.-s.-1.
A-
'