ML20072S292

Proposed Tech Specs Supporting Rev of APRM Channel Calibr Interval from Weekly to Quarterly

ML20072S292
Person / Time
Site:	Oyster Creek
Issue date:	09/02/1994
From:	GENERAL PUBLIC UTILITIES CORP.
To:
Shared Package
ML20072S284	List: ML20072S281 ML20072S292
References
NUDOCS 9409140028
Download: ML20072S292 (7)

Text

-

Attachment 3 l

9409140028 940902 PDR ADOCK 05000219 P PDR

The scram discharge volume has two separate instrument volumes utilized to

. detect water accumulation. The high water level is based on the design that the water in the SDIV's, as detected by either set of level instruments, shall not be allowed to exceed 29.0 gallons; thereby, permitting 137 control rods to scram. To provide further margin, an accumulation of not more than 14.0 gallons of water, as detected by either instrument vol ume, will result in a rod block and an alarm. The accumulation of not more than 7.0 gallons of water, as detected in either instrument volume will result in an alarm.

Detailed analyses of transients have shown that sufficient protection is provided by other scrams below 45% power to permit bypassing of the turbine trip and generator load rejection scrams. However, for operational convenience, 40% of rated power has been chosen as the setpoint below which these trips are bypassed. This setpoint is coincident with bypass valve capacity.

A low condenser vacuum scram trip of 20 inches Hg has been provided to protect the main condenser in the event that vacuum is lost. A loss of condenser vacuum would cause the turbine stop valves to close, resulting in a turbine trip transient.

The low condenser vacuum trip provides a reliable backup to the turbine trip. Thus, if there is a failure of the turbine trip on low vacuum, the reactor would automatically scram at 20 inches Hg. The condenser is capable of receiving bypass steam until 7 inches Hg vacuum thereby mitigating the transient and providing a margin.

The settings to isolate the isolation condenser in the event of a break in the steam or condensate lines are based on the predicted maximum flows that these systems would experience during operation, thus permitting operation while affording protection in the event of a break. The settings correspond5 to a flow rate of less than three times the normal flow rate of 3.2X10 l b/hr. Upon initiation of the alternate shutdown panel, this function is bypassed to prevent spurious isolation due to fire induced circuit faults.

The setting of ten times the stack release limit for isolation of the air-ejector offgas line is to permit the operator to perform normal, immediate remedial action if the stack limit is exceeded. The time necessary for this action would be extremely short when considering the annual averaging which is allowed under 10 CFR 20.106, and, therefore, would produce insignificant effects on doses to the public.

j l

l l

! OYSTER CREEK 3.1-5 Amendment No.: 73,149,152,169 i

l l

Four radiation monitors are provided which initiate isolation of the i reactor building and operation of the standby gas treatment system. Two I monitors are located in the ventilation ducts, one is located in the area l of the refueling pool and one is located in the reactor vessel head l storage area. The trip logic is basically a 1 out of 4 system. Any ,

upscale trip will cause the desired action. Trip settings of 17 mr/hr in the duct and 100 mr/hr on the refueling floor are based upon initiating standby gas treatment system so as not to exceed allowed dose rates of 10 CFR 20 at the nearest site boundary.

5 The SRM upscale of 5 x 10 CPS initiates a rod block so that the chamber can be relocated to a lower flux area to maintain SRM capabiljty as power is increased to the IRM range. Full scale reading is 1 x 10 CPS. Thig rod block is bypassed in IRM Ranges 8 and higher since a level of 5 x 10 CPS is reached and the SRM chamber is at its fully withdrawn pm ition.

The SRM downscale rod block of 100 CPS prevents the instrument chamber from being withdrawn too far from the core during the period that it is required to monitor the neutron flux. This downscale rod block is also bypassed in IRM Ranges 8 and higher. It is not required at this power level since good indication exists in the5 Intermediate Range and the SRM will be reading approximately 5 x 10 CPS when using IRM Ranges 8 and higher.

The IRM downscale rod block in conjunction with the chamber full-in position and range switch setting, provides a rod block to assure that the l IRM is in its most sensitive condition before startup. If the two latter conditions are satisfied, control rod withdrawal may commence even if the IRM is not reading at least 5%. However, after a substantial neutron flux is obtained, the rod block setting prevents the chamber from being withdrawn to an insensitive area of the core.

The APRM downscale setting of 2 2/150 full scale i. o*cvided in the RUN MODE to prevent control rod withdrawal without adequate neutron monitoring. ,

High flow in the main steamline is set at 120% of rated flow. At this setting the isolation valves close and in the event of a steam line break l limit the loss of inventory so that fuel clad perforation does not occur. l The 120% flow would correspond to the thermal power so this would either l indicate a line brenk or too high a power.

Temperature sensors are provided in the steam line tunnel to provide for closure of the main steamline isolation valves should a break or leak occur in this area of the plant. The trip is set at 50*F above ambient l temperature at rated power. This setting will cause isolation to occur for main steamline breaks which result in a flow of a few pounds per l minute or greater. Isolation occurs soon enough to meet the criterion of no clad perforation.

i l

OYSTER CREEK 3.1-6 Amendment No.: 2,7 01/5/71, 11/5/71

r l

TABLE 3.1.1 PROTECTIVE INSTRUMENTATION REQUIREMENTS Reactor Modes Min. No. of Min. No. of j l in which Function OPERABLE or Instrument Must Be OPERABLE OPERATING Channels Per Trip [ tripped] OPERABLE Action Function Setting Shutdown Refuel Startup Enn Trio Systems Trio System Recuired* ,

1 A. Scram

> 1

1. Manual Scram X X X X 2 1 Insert  !

control High Reactor " X 2 rods l

2. X(s) X(ll) 2(nn) l Pressure l 3. High Drywell 5 3.5 psig X(u) X(u) X 2 2(nn) l Pressure

4. Low Reactor " X X X 2 2(nn) l Water Level l 5. a. High Water 5 29 gal. X(a) X(z) X(z) 2 2(nn) l level in Scram Discharge Volume North Side

b. High Water 129 gal. X(a) X(z) X(z) 2 2(nn) l Level in Scram Discharge Volume South Side

6. Low Condenser p,_20 in. hg. X(b) X 1 3(mm)(nn) l Vacuum

7. DELETED ,

Average Power "

8. X(c,s) X(c) X(c) 2 3(nn) l Range Monitor (APRM)

9. Intermediate X(d) X(d) 2 3(nn) l l Range Monitor (IRM)

10. Main Steamline X(b,s) X(b) X 2 4(nn) l Isolation Valve Closure

11. Turbine Trip X(j) 2 4(nn) l Scram

12. Generator load "

X(j) 2 2(nn) l Rejection Scram )

l l

l OYSTER CREEK 3.1=9 Change: 4,8 Amendment No.: 20,44,79,112,131, i 149,162,169 l

- l TABLE 3.1.1 PROTECTIVE INSTRUMENTATION REQUIREMENTS Reactor Modes Min. No. of Min. No. of ,

in which Function OPERABLE or Instrument l Must Be OPERABLE OPERATINO Channels Per i Trip [ tripped] OPERABLE Action Function Setting Shutdg_wn Refuel Startup Eun Trio Systems Trio System Reauired*

B. Reactor Isolation Close main steam

1. Low-law Reactor X X X X 2 2(oo) isolation l Water Level valves and close ,

2. High Flow in 5120% rated X(s) X(s) X X 2 2(oo) isolation l Main Steam- condenser

! line A vent vahrs, or PLACE IN

3. High Flow in 5120% rated X(s) X(s) X X 2 2(oo) COLD SHUT- l Main Steam- DOWN line B CONDITION

4. High Temp- SAmbient X(s) ' X(s) X X 2 2(oo) l erature in at Power +

Main Steam- 50*F line Tunnel

5. Low Pressure X(cc) X 2- 2(oo) l in Main Steam-line

6. DELETED C. Isolation Condenser initiation .

1. High Reactor X(s) X(s) X(ll) X 2 2(pp) PLACE IN

Pressure COLD SHUT-DOWN

2. Low-Low 172* above X(s) X(s) X X 2 2(pp) CONDITION Reactor TOP OF ,

Water Level ACTIVE FUEL l

l l OYSTER CREEK 3.1-10 Amendment No.: 44,131,169-

, TA'BLE 3.1.1 PROTECTIVE INSTRUMENTATION REQUIREMENTS Reactor Modes Min. No. of Min. No. of in which Function OPERABLE or Instrument Must Be OPERABLE OPERATING Channels Per Trip [ tripped) OPERABLE Action Function Setting Shutdown Refuel Startup Elin Trio Systems Trio System Reauired'

! K. Rod Block No control rod

1. SRM Upscale 15x105 cps X X(1) 1~ 2 withdrawals permitted

2. SRM Downscale 2.100 cps (f) X X(1) 1 2

3. IRM Downscale 2.5/125 X X 2 3

, fullscale (g) t

4. APRM Upscale " X X 2 j X(s) 3(c) f l 5. APRM Down- 2.2/150 X 2 3(c)-

scale fullscale

6. IRM Upscale $108/125 X X 2 3

fullscale

7. a) water level 114 gallons X(z) X(z) X(z) 1 1 per j high scram instrument  ;

discharge volume volume North j b) water level 114 gallons X(z) X(z) X(z) 1 1 per

! high scram instrument I

discharge volume ,

volume South L. Condenser Vacuum Pumo Isolation DELETED 1

l l

l  !

l l

1 0YSTER CREEK 3.1-13 Amendment No.: 44,63,75,169 )

i

^

TABLE 4.1.1 (cont'd)

Instrument Channel Check Calibrate Test Remarks (Applies to Test and Calibration)

13. DELETED

14. High Radiation.in Reactor Building  ;

Operating Floor 1/s 1/3 mo 1/3 mo Using gamma source for '

Ventilation Exhaust 1/s 1/3 mo 1/3 mo calibration

15. High Radiation on 1/3 mo 1/3 mo Using built-in calibration l Air Ejector Off-Gas equipment 1/s Channel Check  :

1/mo Source check  !

1/24 mo Calibration according to established station calibration procedures i 1/24 mo Note a r

16. IRM Level N/A Each N/A startup ,

IRM Scram * *

• Using built-in calibration equipment ,

17. IRM Blocks N/A Prior Prior Upscale and downscale to to startup startup  :

and and shutdown shutdown

18. Condenser low N/A 1/20 mo 1/20 mo Vacuum

19. Manual Scram Buttons N/A N/A 1/3 mo ,

20. High Temperature Main N/A 1/20 mo Each Using heat source box Steamline Tunnel refueling outage -

L I

l l

)

1 0YSTER CREEK 4.1-4 Amendment No.: 71,108,141,169 Change: 7

.. . .