ML20155E180

Proposed Tech Specs Re Trip Setpoints for Safety Channels

ML20155E180
Person / Time
Site:	Neely Research Reactor
Issue date:	10/03/1988
From:	Neely Research Reactor, ATLANTA, GA
To:
Shared Package
ML20155E168	List: ML20155E165 ML20155E180
References
NUDOCS 8810120157
Download: ML20155E180 (9)

Text

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TABLE 3.1 REQUIRED SAFETY CHANNELS .

1 Mode 1 Mode 2  :*inimum No.

Channe1-Setpoint Setpoint Required Function stare up (ros! 2 2 1(a) Minimum count rate permissive

, rod withdrawal interlock i

i Pc t2 O J t Q (ce r +) >10 >10 2(c) Scram I

power trip (MW) 1.25 5.5 2(c) Scram .

1 Scram EDw D,0 flo. (gym) 1000 1625 2(b) (c)

High D,0 temperature (0F) JJT 139 2(c) Scram

Low D,0 level (inches below <12 <12 2(c) Isolate reactor vessel Ovcrflow) Scram l\

Initiate ECCS L u

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1 Scram No D,0 Overflow Manual scram - -

1 Scram Reficctor drain - -

1 Backup Scram Containment doors open - -

1 per airlock Scram Rcactor isolation valves closed - - 2 per valve Scram (a) Required during startup and for operation with less than 1 decade overlap between the startup channel and the pico-ammeter channel.

(b) Riot required for natural convection operation.

(c)one of the twelve required safety channel may be bypassed for a period not to excced 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> for test, repair, or calibra tion.

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The primary coolant flow rate scrams and provides redundant I channels to assure, when the reactor is at power levels which '

require forced flow cooling, that an automatic shutdown of the I reactor will occur to prevent exceeding a safety limit if l sufficient flow is not maintained.

Two redur. dant 3D 0 temperature scrams provide automatic protection against exceedihg the core inlet temperature safety limit in the event of a failure of the secondary coolant system to adequately dissipate the heat removed from the primary coolant system.

i A loss-of-coolant accident is detected by two low D0 level l scrams which also isolate the reactor vessel to prevent2 coolant loss through the primary coolant piping and initiate the emergency core coolant system. l In addition to the automatic protective systems, the manual scram and the reflector drain provide backup methods to shut the reactor down by operator action. The reflector drain provides a 1 shutdown capability of 2.75% Ak/k.

The containment doors open scram assures that the r# .ctor is not made critical with both doors open on an airlock.

Two switches shich sense the position of each of the reactor isolation valves initiate a reactor scram upon closure of these ,

valves to prevent damage to the cladding due to a loss of coolant  !

flow, i 3 The pico ammeter channel provides a narrow range indication of

reactor power level over all ranges of reactor operation above the range of the start up channel thereby assuring that the  ;

operator has an accurate monitoring channel available for l comparison to the safety channels. l The building area radiation monitors assure that areas throughout l

, the facility in which high radiation areas could occur due to l

] improper sample handling, equipment or shielding movements, etc. l The gas monittr, filter assembly monitor, Kanne chamber and the particulate monitor provide diverse and redundant channels which monitor particulate and gaseous releases from the reactor

building. These monitors provide readout and alarm functions in the control room and initiate a containment isolation in the event that their present alarm points are exceeded. In addition the D 2 0 leak i

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) 3.4 LIMITATIONS OF EXPERIMENTS j i

! APPLICABILITY j l These specifications apply to experiments performed at the  ;

1 GTRR. l l t OBJECTIVE f J

I To prevent damage to the reactor and to limit radiation dose to facility personnel and the public in the event of I experiment failure. l t

SPECIFICATIONS 4

! a. The potential reactivity worth of each secured l removable experiment shall be limited to 0.015 ok/h.  ;

b. The magnitude of the potential reactivity of each  !

I j unsecured experiment shall be limited te 0.004 Ak/k.

j c. The rate of change of reactivity of any unsecured {

i experiment, any movable experiment, or any combination .

l of such experiments have a total reactivity worth in  !

excess of 0.0025 4k/k introduced by intentionally j l setting the experiment (s) in mc. tion relative to the i l reactor shall not exceed 0.0025 A k/k-sec. l

, d. The sum of the magnitudes of the static reactivity (

j worths of all unsecured experiments which coexist shall '

not exceed 0.015 Ak/k.  !

!' e. The uurface temperature of the material which bounds or  ;

supports any experiment shall not exceed the lowest of '

I the following, where applicable:

(1) The saturation temperature of liquid reactor  ;

coolant at any point of mutual contact.

l (2) A temperature conservatively below that at which I the strength of the boundary material at any

surface would lead to its failure, or, j (3) A temperature conservatively below tnat at which the strength of the boundary material would be

reduced to a point predictably leading to failure, j f. Materials of construction and fabrication and assembly l techniques utilized in experiments shall be so 1 specified and used that assurance is provided that no

! stress failure can occur at stresses twice those j anticipated in the manipulation and conduct of the i experiment or twice those which could occur as a result 3

of unintended but credible changes of, or within, the experiment.

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g. The radioactive material content, including fission products, of any singly encapsulated experiment shall be limited so that the complete release of all gaseous, particulate, or volatile components from the i encapsulation will not result in doses in excess of 10% )

of the equivalent annual doses stated in 10 CFR Part .

20. This dose limit applies to persons occupying (1) l unrestricted areas continuously for two hours starting at time of release or (2) restricted areas during the length of time required to evacuate the restricted area.

h. The radioactive material content, including fission  ;

products, of any doubly encapsulated or vented experiment shall be limited so that the complete release of all gaseous, particulate, or volatile l components fro n the encapsulation or confining boundary of the experiment could not result in (1) a dose to any person occupying an unrestricted area continuously for a period of two hours starting at the time of release in excess of 0.5 rem to the whole-body or 1.5 rem to the thyroid or (2) a dose to any person occupying a ,

restricted area during the length of time required to evacuate the restricted area in excess of five rem to the whole-body or 30 rem to the thyroid.

i. Explosive materials in excess of 25 milligrams of TNT equivalent shall not be irradiated or stored within the  !

reactut containment building.

1 j. Explosive materials in amounts up to 25 milligrams TNT ,

! equivalent may be irradiated and storci within the  !

containment only if they are encapsulated in such a i

manner to assure compliance with Specification 3.4.f in I the event of detonation of the explosive material. i

k. Experiments which could increase reactivity by flooding, shall not remain in or adjacent to the core unless measurements are made to assure that the shut i down margin required in Specification 3.1.a would be l 1 satisfied after flooding. l BASIS Limiting the potential reactivity worth of secured removable experiments to 0.015 a k/k assures that any transient arising i

from the instantaneous removal of such experiments will not l

. result in cladding failure and concomitant release of '

radioactive material which could lead to doses in excess of

] the limits set forth in 10 CFR Part 20, i i

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A positive step change caused by the ejection or insertion of unsecured experiments worth less than 0.004a k/k would not result in a transient behaviour exceeding the Safety Limits established in Section 2.1 of these Specifications.  ;

Manipulations of movable experiments within the limits established in Specification 3.4.c will result in asympt. otic periods longer than 20 seconds. Periods of this magnitude are l easily accommodated by automatic response of the reactor safety system or by operator action. Prior to \ i manipulation of movable experiment the reactor power level .211 be reduced as required to accommodate the calculated prompt jump associated i with the step insertion of the potential reactivity worth of the j experiment.

Conformance with Specification 3.4.d assures that common mode failures resulting in the insertion of the total reactivity worth of all unsecured experiments will not result in accident consequences more severe than those evaluated for the failure of a single secured experiment.

Specifications 3.4.0 and 3.4.f provide assurance that experiments ,

will not fail due to the pressure or temperature effects of ,

operation under anticipated operating conditions. For the purposes of this specification the reactor shall be assumed to be i operating at the Limiting Safety System Settings established in Section 2 of these Technical Specifications.

Specifications 3.4.g and 3.4.h will assure that the quantities of radioactive materials contained in experiments will be limited such that their failure will not result in restricted or  ;

unrestricted area doses which exceed the maximum annual exposures l stated in 10 CFR 20.

Adherence to Speci.fication 3.4.1 will prevent large quantities of explosives from being present within the reactor containment building and thereby preclude damage to the safety system and safety related equipment. Small quantities of explosive material may be safely used and stored as long as the encapsulation used has been shown to withstand the detonation of twice che qaantity of explosive to be used.

Specification 3.4.k assures that the shutdown margin required by Specification 3.1.a will be met in the event of a positive reactivity insertion caused by the flooding of an experiment.

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! An analysis was made to determine the time-fuel temperature

! relationship that occurs following removal of a fuel element i from the core into the fuel transfer cask. These results, detailed in the basis for specification of 3.3 indicate that j the maximum fuel plate temperature reached following 12 1 i hours of cooling before removal into the cask will be 361 C.

This provides a sufficient margin to assure that no fuel plate melting will occur.

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! REFERENCES j

j (1) Final Safeguards Report for the GTRR, February 1963, l 1 Section 7.7, pp. 96-97. j

{ (2) See correspondence relative to Change No. 10 to the 1

' Technical Specificaticn of Operating License No. R-97, j Docket 50-160

(3) Safety Analysis Report for the 5 Mw GTRR, GT-NE 7, f December 1967, Section 4.4.10.

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Vice President Safeguards for Committee (Chrt  ;

interdisciplinary Radia tion Safety Programs Officer) >

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j , l l Reporting Office of the ,,. _ _ _.J (Safety and NNRC Director Safety Policy)

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, Admin. Reporting i I I I I Manager of Manager of Coordinator of Manager, Office '

I Reactor Gamma Radiation Experimen tal of Radiation '

y Opera tions Orv2ations Rascarch Sa fe ty f

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a O Pigure 6.1 Georgia Tech Organization for Manager and Operation of GTRR i

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(2) The Licensed Operator at the console shall be notified just prior to moving any experiment with-in the reactor area and should authorize such movement.

(3) Each experiment removed from the reactor or a reactor system shall be subject to a radiation monitoring procedure which anticipates exposure rates greater than those predicted. The results of such monitoring should be documented.

d. Procedures Relating to Personnel Access to

Experiments j (1) There shall be a documented procedure for the control of visitor access to the reactor area to 4

minimize the likelihood of unnecessary exposure to radiation as a result of experimental activities and to minimize the possibility of intentional or i

, unintentional obstruction of safety.

(2) There shall be a written training procedure for 3

the purpose of qualifying experimenters in the  ;

reactor and safety related aspects of their activities, including their expected responses to alarms.

e. Quality Assurance Program f There shall be a Quality Assurance Program covering the design, fabrication, and testing of experiments, in- ,

cluding procedures for verification of kinds and !

I amounts of their material contents to assure compliance with the technical specifications in Section 3.4. i

6.4 PROCEDUdES i

a. All procedures and major changes thereto shall be i reviewed and approved by the Nuclear Safeguards f 1 Committee prior to being effective. Changes which do not alter the original intent of a procedure may be  ;

approved by the director of the facility. Such changes i shall be recorded and submitted periodically to the l Nuclear Saf t. guards Cwnmitteo for routine review.  :

b. Urltten procedures shall be provided and utilized for '

the following

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i (1) Normal startup, operation and shutdown of the reactor and of all systems and components i involving nuclear safety of the system.

1 (2) Installation and removal of fuel elements, control '

blades , exp<.riments and experimental f acilities . l

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! 6.6 ACTION TO DE TAKEN I N, THE EVENT OF A REPORTABLE OCCURRENCE d

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j In the event of a reportable occurrence, as defined in I

l these Technical Specifications, the following action j shall be taken l a. All reportable occurrences shall be promptly  !

reported to the director of the facility.

b. All reportable occurrences shall be reported to the Nuclear Regulatory Commission in accordance  ;

with Section 6.7 of these specifications.  !

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c. All reportable cecurrences shall be reviewed b .* l the Nuclear Safeguards Committee. l 6.7 f l R$ PORTING REQUIREMENTS 4 l i Tne following information shall be submitted to the i i U.S.N.R.C. in addition to the reports required by Title

) 10, Code of Federal Regulations.

j a. Annual Operating Reports _

l A report covering the previous year shall be [

submitted to the office of the Regional i

] Administrator, Region II, with a copy to the i Directo7, Office of Nuclear Reactor Regulation, by i March 1 of each year. It shall include the  ;

j followings l l

) (1) Operations Summary j

] A summary of operating experience occurring

] during the reporting period incuding:

,1 (a) changes in facility design, 1 (b) performance characteristics (e.g.,

! equipment and fuel performanco),

l (c) cnanges in operating procedures which 1

relate to the safety of facility j operations,

! (d) results of surveillance *ests and inspections required by thes technical 4 specifications, 1' (e) a brief summary of these changes, tests, j and experiments which required i j authorization from the Commission 1

, pursuant to 10 CFR 50.59(a), and i j (f) changes in the plant operating staff ,

j serving in the following positions: I j.

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