ML20003C302

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Proposed Revisions to Tech Specs,Incorporating Stability & Recirculation Pump Trip Tests
ML20003C302
Person / Time
Site: Vermont Yankee Entergy icon.png
Issue date: 02/12/1981
From:
VERMONT YANKEE NUCLEAR POWER CORP.
To:
Shared Package
ML20003C301 List:
References
NUDOCS 8102270610
Download: ML20003C302 (25)


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4 Attachment I CD h Description of Proposed Changes to Technical Specifications Snction- Location Change Reason 3.6.J P. 110b Replace 3.6.J in-.its entirety with the Performance of the proposed stability following: and pump trip tests requires operation in the natural circulation mode.

1. .When the reactor mode switch is in RUN, the reactor shall not intentionally be operated in a natural circulation mode, except as permitted in 3.6.J.2 below, nor shall an idle recirculation pump be started with the reactor in a natural circulation mode, except as permitted in 3.6.J.2.
2. For the purpose of performing special tests, operation in the natural circulation mode is perinitted. For the purpose of recovering forced circulation operation during .and af ter special tests at natural circulation, start-up of an idle recirculation pump is permitted if:
a. The AT between the idle loop and vessel saturation temperature is <50 F.
b. The AT between the idle and an operating loop is f,50 F.
c. The AT between the vessel top head and the vessel bottom head is f,14T"F.

Page 2 of 10 4

Reason Location Change Srction.

J. . Thermal Hydraulic Stability 4.6.J Operation in the natural circulation mode shall be timed and - recorded 'for special tests. Also, during special tests. loop temperatures, vessel saturation temperature,

-(pressure), vessel top head temperature and vessel bottom head temperature shall be monitored and recorded.

Replace the first sentence of 2.1.A.I.a The recirculation pump trip and 2.1.A.1 P. 5 with the following.

stability test points VPT4, VPT3 and VPT2, (Figure 2-1, Reference 2) require a higher flux scram trip setting to perform the tests. It is also necessary to remove the peaking factor setdown When the Mode Switch is in the RUN requirement to assure that these test points position, the_APRM flux scram trip can be reached. When the testing is concluded setting shall be (except as permitted in and normal forced circulation is recovered, 2.1.A.1.b for special stability testing) the settings shall revert < < ,

as shown on Figure 2.1.1 and shall the original requirements.

be:

S _< 0.66W + 54%

2.1.A.1 P. 5-a where:

S = setting in percent of rated thermal power (1593 NWt)

W = percent rated drive flow where 100%

.rateddriveflowistgatflow equivalent to 48 x 10 lbs/hr core flow.

Change the section label of 2.1.A.1.b to 2.1.A.1.c.

Insert the following as 2.1.A.1.b:

1 1

Page 3 of 10 Change Reason Section Location

b. APRM Flux Scram Trip Setting (Run Mode, Special Testing)

For the purpose of performing special

. stability test when the Mode Switch is in the RUN position, the APRM flux scram trip setting shall be:

S .< 0.66W + 85%

For no combination of loop recirculation -

flow rate and core thermal power shall the APRM flux scram trip setting be allowed to exceed 1207, of rated thermal power.

During operation under the provisions of 2.1.A.1.b, the special MAPLHCR limits of 3.11.A shall apply and such operation shall be limited to the duration of pump trip and stability tests.

Adjustments for the ratio of MFLPD to FRP greater than 1.0 are not required while conducting special testing under this provision.

5-a, 6 Replace the first sentence of 2.1.B with The recirculation pump trip and stability 2.1.B test points VPT4, VPT3 and VPT2 the following.

(Fig. 2-1, Ref. 2) are above the APRM rod block trip. A higher setting is required to perform the tests. As in the case or

.The APRM rod block trip setting shall the flux scram trip, it is necessary to 1.

he as shown in Figure 2.1.1 and shall remove the peaking factor setdown requirement i to assure that these test points can be be (except as permitted in 2.1.B.2 for reached. When the testing is concluded special stability testing):

and normal forced circulation is recovered, the settings shall revert to the original requirements.

SRB < 0.66U + 42%

Page 4 of 10 .

Reason Location Change

'Section where:

.S RB = rod block setting in percent of rated thermal power 1593 MWt W = percent rated drive flow where 100% rated drive flow is tgat flow equivalent to 48 x 10 7bs/hr core flow.

Add the following subsection:

2. For the purpose of performing special stability tests the APRM rod block trip setting shall be:

S RB < 0.66W + 75%

During operation under the provision of 2.1.B.2, the special MAPLHCR limits of 3.11.A'shall apply and such operation shall be limited to the duration of punp trip and stability tests. Adjustments for the ratio of MFLPD to FRP greater than 1.0 are not required while conducting special tests under this provision.

Ce sistent with change to Section 2.1.A.1

'3.1 P.19, 21a Add note 12. to Table 3.1.1 No+e-:

12. For special stability tests the APRM flux scram shall be <0.66W + 85% for the duration of testing. Adjustments for the ratio of MFLPD ro FRP greater than 1.0 are not required while conducting special tests.

_- . - . . . - .. . . . . -. - - . ..=. - . ~ _ ... -. . . - .

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Page 5 of 10 Change Reason -

Srction Location.

I

'Changa Table 3.1.1 as indicated on the following page.

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Consistent with change to Section 2.1.B'

,3.2 P. 47,~48 fAdd Note 8. to Table'3.2.5 Notes:

I '8. For special. stability tests the APRM rod

-block.shall he <0.66W + 75% for the

. duration of testing.

]

Change Table 3.2.5 as indicated.

t i

i 2

1 1

T-i b

1

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'Page 6'of 10 t

i- VYNPS ,

t TABLE 3.1.1 (Description of Changes)

REACTOR PROTECTION SYSTEM (SCRAM) INSTRUMENT REQUIREMENTS Modes in Which Minimum Number Required Conditions When Functions Must be Operating Instrument Minimum Conditions For Operating Channels Per Operation Are Not Trip Function Trip Settings Refuel (1) Startup Run Trip System (2) Satisfied (3) 4 X X 1 A

1. Mode Switch X

.in Shutdown

'X X X 1 A

2. Manual Scram G 3. IRM X X X(11) 2 A liigh Flux 1120/125.

X X X(11) 2 A

.Innp

+

4. APRM X 2 A or B High Flux 10.66W+54%(4)(12)

, (flow bias) 2 A

liigh Flux 115% X' X
(reduced)

' Inop X 2(5) A or B ,

X 2 A or B

< Downscale >2/125 X X 2 A

5. liigh Reactor 11055 psig X l Presstire i

X. X 2 A

6. High Drywell 12.5 psig X Pressure

\

l 2 A

7. Reactor Low >1.0 inch (6) X X X Water Level X X X 2 A
8. Scram Discharge -<24 gallons Volume fligh Level

Page 7 of 10 VYNPS TABLE 3.2.5 (Description of Changes)

CONTROL ROD BLOCK INSTRUMENTATION 7

Minimum Number-7f Modes in Which Function

Operable Instrument Must be Operable Chennels per Trip Run Trip Setting Trip Function Refuel Startup
Systzm'(Note 1)

Startup Range Monitor

a. Upscale (Note 2) X X f,5 x 105 cps (Note 3) 2 X Detector not fully inserted X 2 b.

Intermediate Range Monitor 2 a. Upscale X X f108/125 full scale 2 b. Downscale (Note 4) X X ->5/125 full scale Detector not-fully inserted X X 2 c.

Average Power Range Monitor X <0.66W + 42% (Note 5)(Note 8) 2 a. Upscale (flow bias) 2 b. Downscale X [2/125fullscale Rod Block Monitor (Note 6)

Upscale (flow bias)(Note 7) X f,0.66W + N (Note 5) a.

1 Downscale (Note 7)

X >2/125 full scale 1 .b.

X X X 1 Trip System Logic Scram Discharge Volume X X X f,12 gallons 1

Page 8 of 10 Change Reason Section- Location 3.11.A P. 180-a, Replace the existing Section 3.11.A in its-

.180-b entirety with the following:

A. Average Planar Linear Heat Generation Special MAPLHCR limits will be observed Rate (APLHGR) in lieu of the standard flow biased APRM rod block settings.

During steady state power operation, the APLHGR for each. type of fuel'as a function of average planar exposure shall not. exceed'the limiting values shown in Tables 3.11-1A-through G (except as specified in Section 3.11.A.1 for Special Stability Testing.)

If at any time during steady state operation it is determined by normal surveillance that the limiting value for APLHGR is being exceeded, action shall be initiated within 15 minutes to restore operation to within the prescribed limits. -If the APLHGR is not returned to within prescribed limits within two (2) hours, the reactor shall be brought to the shutdown conditions within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Surveillance and corresponding action shall continue until reactor operation is within the prescribed limits.

1. The flow-biased APRM rod block normally provides'the LOCA margin required for operation at reduced flow.

This assurance will be diminished when the APRM rod block trip is increased; therefore, special restrictions on MAPLHGR's are required for operation in that mode. After adjustment of the APRM rod block setting, the MAPLHGR's shall be 80% of the limits specified in Tables 3.11-1A through G.

Page 9 of 10 Change Reason S;ction Location 3.11.C Table Replace Table 3.11-2 in its. entirety.with the .To assure that the desired natural enclosed table, circulation stability test points 3.11-2 can be achieved, it is necessary to P. 180-01 remove the normal MCPR operating limits as determined with the Kf multiplier.

The enclosed table reflects the cycle 3 normal MCPR operating limits and special testing MCPR limits based on evaluation of limiting transients at natural circulation conditions (Reference 2).

Page 10 of 10

??

(Description of Changes)

VYNPS Table 3.11-2 MCPR Operating Limits Value of "N" Fuel Type (2) in Exposure Range RBM Equation (1) 8x8 8 x 8R P8 x 8R 42% 1.21 1.26 1.27 BOC to EOC-2_GWd/t 41% 1.21 1.22 1.23 40% 1.21 1.21 1.22 f,39% 1.21 1.21 1.21 42% 1.26 1.26 1.28 EOC-2 GWd/t to EOC-1 GWd/t 41% 1.26 1.26 1.28 f,40% 1.26 1.26 1.28 42% 1.29 1.29 1.31 EOC-1 GWd/t to EOC 41% 1.29 1.29 1.31 j;40% 1.29 1.29 1.31 1.30 1.31 1.31 Special Testing at Natural 75%

Circulation (Note 3,4)

(1) l The rod block monitor trip setpoints are determined by the equation shown in Table 3.2.5 of the Technical Specifications.

(2) The current analysis for MCPR Operating Limits do not include 7x7 fuel.

On this basis further evaluation of MCPR operating limits is required before 7x7 fuel can be used in Reactor Power Operation.

(3) For the duration of' pump trip and' stability testing.

(4) K f factors are not applied during the pump trip and stability testing.

VYNPS 2.1 LIMITING SAFETY SYSTEM SETTING 1.1 SAFETY LIMIT

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2.1 FUEL CLADDING INTEGRITY 1.1 FUEL CLADDING INTEGRITY Applicability:

Applicability:

Applies to the interrelated variable associated with Applies to trip settings of the instruments and devices which are provided to prevent the fuel thermal behavior. nuclear system safety limits from being exceeded.

Objective:

Objective:

To estat.lish limits below which the integrity of the To define the level of the process variable at fuel cladding is preserved.

which automatic protective action is initiated.

Specification: Speci fic,it ion:

Bundle Safety Limit (Reactor Pressure A. Trip Settings A.

>800 psia and Core Flow >10% of Rated) The limiting safety system trip settings shall When the reactor pressure is >800 psia and core be as specified below:

flow is >10% of rated, the existence of a Minimum Neutron Flux Trip Settings Critical Power Ratio (MCPR) less than 1.07 shall 1.

constitute violation of the fuel cladding

a. APRM Flux Scram Trip Setting (Run Mode) integrity safety limit.

When the Mode Switch is in the RUN position, the APRM flux scram trip set-ting shall be (except as permitted in 2.1.A.l.b for special stability testing) as shown on Figure 2.1.1 and shall be:

S <0.66W + 54%

5

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.VYNPS .

- 1.1 . SAFETY LIMIT- 2.1 ' LIMITING SAFETY SYSTEM SETTING where:

S = setting in percent of rated thermal power (1593 MWt)

W = percent rated drive flow where 100% rated drive flow is that flow equivalent to 48 x 10 lbs/hr core flow.

In the event of operation with the ratio of l

MFLPD to FRP greater than 1.0, the APRM gain shall be increased by the ratio: MFLPD FRP J

where: MFLPD = maximum fraction of limiting power density where the limiting power density is 13.4 kW/ft for '

8x8 fuel.

r FRP = fraction of rated power (1593 MWt).

In the event of operation with the ratio of i

MFLPD to FRP equal to or less than 1.0, the i

APRM gain shall be equal to or greater than 1.0.

For no combination of loop recirculation flow rate and core thermal power shall J

the APRM flux scram trip setting be allowed to exceed 120% of rated thermal power.

4

b. APRM Flux Scram Trip Setting (Run Mode, Special Testing) e Sa

_ .. , _. . _ _ . , _ . . . . _ =_ . _ . _ _ _

VYNPS .

'1.1. SAFETY LIMIT' '2.1 LIMITING SAFETY SYSTEM SETTING For the purpose of performing special stability testing when the Mode Switch is in in the RUN position, the APRM flux scram trip setting shall be:

S <0.66W + 85%

For no combination of loop recircalation flow rate and core thermal power shall the APRM flux scram trip setting be allowed to exceed 120% of rated thermal power.

During operation under the provisions of

.2.1. A.1.b, the special MAPLHGR limits of 3.11.A shall apply and such operation shall be limited to the duration of pump trip and stability tests.

Adjustments for the ratio of MFLPD to i FRP greater than 1.0 are not required while conducting special testing under this provision.

c. Flux Scram Trip Setting (Refuel or Startup and Hot Standby Mode)

When the reactor Mode Switch is in the REFUEL or STARTUP position, average power range monitor ( APRM) scram shall be set down to less than or equal to 15% of rated neutron flux. The IRM flux scram setting shall be set at less than or equal to 120/125 of full scale, i l

Sb

-. - - ~,

. =. .

VYNPS .

2.1 LIMITING SAFETY SYSTEM SETTING L.1 SAFETY LIMIT B. APRM Rod Block Trip Setting B. Core Thermal Power Limit (Reactor Pressure 1 800 psia or Core Flow 1 of Rated)

When the reactor pressure is <800 psia or core 1. The APRM rod block trip setting shall flow <10% of rated, the core thermal power as shown in Figure 2.1.1 and shall be shall'not exceed 25% of . rated thermal power. (except as permitted in 2.1.B.2 for special stability testing):

C. Power Transient S RBf p.66W + 42%

To. ensure that the Safety Limit established in Specification 1.1A and 1.,B is not 1

where:

exceeded, each required-scram shall be initiated by its expected scram signal. The = rod block setting in percent of S

Safety Limit shall be assumed to be exceeded RB rated thermal power (1593 MWt).

when scram is accomplished by means other

'than the expected. scram signal. W = percent rated drive flow where 100%rateddriveflowistgat flow equivalent to 48 x 10 lbs/hr core flow.

In the event of operation with the ratio of MFLPD to FRP greater than 1.0, the APRM gain shall be increased by the ratio: MFLPD FRP where: MFLPD = maximum fraction of limiting power density where the Ilmiting power density is 13.4 kW/ft for l 8x8 fuel. I FRP = f raction of rated power (1593 MWt) 6

VYNPS L.1 SAFETY LIMIT 2.1 LIMITING SAFETY SYSTEM SETTING In the event of operation with the ratio of MFLPD to FRP equal to or less than 1.0, the APRM gain shall be equal to or greater than 1.0.

2. For the purpose of performing special stability tests, the APRM rod block trip setting shall be:

S $0.66W + 75%

RB During operation under the provision of 2.1.B.2, the special MAPLHGR limits of 3.11.A shall apply and such operation shall be limited to the duration of pump trip and stability tests.

Adjustments for the ratio of MFLPD to FRP greater than 1.0 are not required while conductir.g special tests under this provision.

6a

VYNPS ,

TABLE 3.1.1

. REACTOR PROTECTION SYSTEM (SCRAM) INSTRUMENT REQUIREMENTS Modes in Which Minimum Number Required Conditions When Functions Must he Operating Instrument Minimum Conditions For Operata 3 Channels Per Operation Are Not Trip Function Trip' Settings Refuel (1) Startup Run Trip System (2) Satisfied (3)

.X X 1 A

1. Mode Switch- X in Shutdown X X 1 A
2. Manual Scram X
3. IRM liigh Flux X X X(11) 2 A 1120/125 X X(11) 2 A Inop X
4. APRM X 2 A or B High Flux . 10.66W+54%(4)(12)

(flow bias) A liigh Flux X X 2 115%

(reduced)

Inop X 2(5) A or B Downscale .>2/125 X 2 A or B X X 2 A

5. liigh Reactor 11055 psig X Pressure- ,

A 2

6. liigh Drywell 12.5psig X X X Prensure 2 A
7. Reactor Iow >1.0 inch (6) X X X Water Level 2 A R. Scram Discharge 124 gallons X X X Volume liigh Level 19

VYNPS 9.. Channel signals for the turbine control valve fast closure trip shall be derived from the same event or events which cause the control valve fast closure.

~

10. A turbine stop valve closure and generator load rejection bypass is permitted when the first stage turbine' pressure.is less than 30 percent of normal (220 psia).
11. The IRM scram is hypassed when the APRM's are on scale and the~ mode switch is in the run position.
12. For special stability tests, the APRM flux scram shall be <0.66W + 85% for the duration of testing.

Adjustments for the ratio of MFLPD to FRP greater than 1.0 are not required while conducting special tests..

21a

VYNPS TABLE 3.2.5

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CONTROL ROD BLOCK INSTRUMENTATION (inimum Number'of Spersble Instrument - - Modes in Which Function Chsnnels per Trip Must be Operable Refuel Startup Run Trip Setting System (Note 1) Trip Function Startup Range Monitor

-2 _

'a. Upscale (Note'2) X X f,5 x 105 cps (Note 3)

b. Detector not fully inserted X X 2

Intermediate Range Monitor 2 a. Upscale X X f,108/125 full scale 2 b. Downscale (Note 4) X X >5/125 full scale

c. Detector not-. fully inserted X X 2

Average Power Range Monitor 2 a. Upscale (flow-bias) X <0.66W + 42% (Note 5)(Note 8) 2 b. Downscale X [2/125fullscale Rod Block Monitor (Note 6) 1 a. Upscale (flow bias)(Note 7) X <0.66W + N (Note 5)

I b. Downscale (Note 7) X [2/125fullscale Trip System Logic X X X 1

1. Scram Discharge Volume X X X f12 gallons 47 l-

VYNPS TABLE 3.2.5 NOTES

1. There.shall be two operable or tripped trip systems for each function in'the required operating mode. ,If the mininum number of operable instruments are not available for one of the two trip systems, this condition may exist for up to seven days provided that during the time the operable system is functionally tested Immediately and daily thereafter; if the condition lasts longer than seven days, the system shall be tripped. If the minimum number of instrument channels are not available for both trip systems, the systems shall be tripped.
2. One of these trips may be bypassed. The SRM function may'be bypassed in the higher IRM ranges when the IRM upscale rod block is operable.
3. This function may be bypassed when count rate is >100 cps or when all IRM range switches are above Position 2.
4. IRM downscale may be bypassed when it is on its lowest scale.
5. "W"gspercentrateddriveflowwhere100%rateddriveflowisthatflowequivalentto48 x 10 lbs/hr core flow. Refer to L.C.O. 3.11.C for acceptable values for N.
6. The minimum number' of operable instrument channels may be reduced by one for maintenance and/or testing for per*,ods not in excess of 24_ hours in any 30-day period.
7. The trip may be bypassed when the reactor power is f30% of rated. . An RBM channel will be considered inoperable if there are less than half the total number of normal inputs from any LPRM level.
8. For special stability tests, the APRM rod block shall be f,0.66W + 75% for the duration of testing.

48

VYNPS .

.3.6 LIMITING CONDITIONS FOR OPERATION 4.6 SURVEILLANCE REQUIREMENTS

2. All hydraulic snubbers whose seal materials are other than ethylene propylene or other material that has been demonstrated to be compatible with the operating environment shall be visually inspected for operability every 31 days.
3. The initial inspection shall be performed within 6 months from the date of issuance of these specifications. For the purpose of entering the schedule in Specification 4.6.I.1, it shall be assumed that the facility had been on a 6-month inspection interval.
4. Once each refueling cycle, a representative sample of approximately 10% of the snubbers shall be functionally tested for oper-ability including verification of proper piston movement, lockup and bleed. For each unit and subsequent unit found inoperable, an additional 10% shall be so tested untti no more failures are found or all units have been tested. Snubbers of rated capacity greater than 50,000 lbs need not be functionally tested.

J. Thermal Hydraulic Stability J. Thermal Hydraulic Stability

1. When the reactor mode switch is in RUN, Operation in the natural circulation mode the reactor shall not intentionally shall be timed and recorded for special be operated in a natural circulation tests. Also, during special tests loop 110b

VYNPS .

4.6 SURVEILLANCE REQUIREMENTS 3.6 LIMITING CONDITIONS FOR OPERATION mode, except .as permitted in 3.6.J.2 temperatures, vessel saturation temperature below, nor shall an11dle recirculation (pressure), vessel top head temperature, and vessel bottom head temperature shall be pump be started with the reactor in a monitored and recorded.

natural circulation mode, except as.

permitted in 3.6.J.2.

2. For the purpose of performing special tests, operation in the natural circulation mode is permitted. For the purpose of recovering forced circulation operation during and after special tests at natural circulation, startup of an idle recirculation' pump is permitted if:
a. The AT between the idle loop and vessel saturation temperature is f,50 F.
b. The AT between the idle loop and an operating loop is f,50 F.
c. 1 The AT between the vessel top head and the vessel bottom head is 3,145 F.

110c

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' VYNPS Table 3.11-2 MCPR Operating Limits Value of "N" Fuel Type (2) in Exposure Range RBM Equation (1) 8x8 8 x 8R P8 x 8R BOC to EOC-2 CWd/t 42% 1.21 1.26 1.27 41% 1.21 1.22 1.23 40% 1.21 1.21 1.22 f,39% 1.21 1.21 1.21 EOC-2 GWd/t to EOC-1 GWd/t 42% 1.26 1.26 1.28 !

41% 1.26 1.26 1.28 1.26 1.26 1.28 f40%

EOC-1 GWd/t to EOC 42% 1.29 1.29 1.31 41% 1.29 1.29 1.31 f,40% 1.29 1.29 1.31 Special Testing at Natural 75% 1.30 1.31 1.31 Circulation (Note 3,4)

(1) The rod block monitor trip setpoints are determined by the equation shown in Table 3.2.5 of the Technical Specifications.

(2) The current analysis for MCPR Operating Limits-do not include 7x7 fuel.

On this basis further evaluation of MCPR operating limits is required before 7x7 fuel can be used in Reactor Power Operation.

l (3) .For the duration of pump trip and stability testing.

(4) K ffactors are not applied during the pump trip and stability testing.

180-01 L

VYNPS ,

~ LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS

.3.11 REACTOR FUEL ASSEMBLIES 4.11 REACTOR FUEL ASSEMBLIES Applicability: Applicability:

The I.imiting Conditions for Operation The Surveillance Requirements apply associated with the~ fuel rods apply to to the parameters which monitor the these parameters which monitor the fuel fuel rod operating conditions.

rod operating conditions.

Objective: Objective:

The Objective of the Limiting. Conditions The Objective of the Surveillance Requirements for Operation is to assure the performance is to specify the type and frequency of surveillance to be applied to the fuel rods.

of the fuel rods.

Specifications: Specifications:

A. Average Planar Linear Heat Generation A. Average Planar Linear Heat Generation Rate (APLHGR) Rate (APLHGR)

During steady state power operation, The APLHGR for each type of fuel as a the APLHGR for each type of fuel as a function of average planar exposure function of average planar exposure shall be determined daily during reactor shall not exceed the limiting values operation at >25% rated thermal power.

shown in Tables 3.11-1A through G (except as specified in Section 3.11.A.1 for Special Stability Testing).

If at any time durinS steady state operation it is determined by normal surveillance that the limiting value for APLHGR is'heing exceeded, action shall be initiated within 15 minutes to restore operation to within the prescribed limits. If the APLHGR is 180-a

VYNPS SURVEILLANCE REQUIREMENTS LIMITING CONDITIONS FOR OPERATION not returned to within prescribed limits within two (2) hours, the reactor shall he brought to the shutdown conditions within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Surveillance and corresponding action shall continue until reactor operation is within the prescribed limits.

1. The flow-biased APRM Rod Block normally provides the LOCA margin required for operation at reduced flow. This assurance will be diminished when the APRM Rod Block trip is increased, therefore special restrictions on MAPLHCR's are required for operation in that mode. After adjustment of the APRM Rod Block setting, the MAPLHCR's shall be .

80% of the limits specified in Tables 3.11-1A through G.

B. Linear Heat Generation Rate (LHCR) B. Linear Heat Generation Rate (LHGR)

During steady state power operation, The LHGR as a function of core the linear heat generation rate height shall be checked daily during (LHGR) of any rod in any fuel assembly reactor operation at 2,25% rated at any axial location shall not exceed thermal power.

the maximum allowable LHGR of 13.4 kW/ft I for 8x8,.8x8R, and P8X8R.

If at any time during steady state C. Minimum Critical Power Ratio

. operation it is determined by normal MCPR shall be determined daily during surveillance that the limiting value for LHCR is being exceeded, action reactor power operation at 2,25% rated shall be initiated within 15 minutes thermal power and following any change to restore operation to within the in power level or distribution that prescribed limits. If the LHCR is not would cause operation with a Ifmiting 180-b

-. . - . - . - . . . . .... . - . . .. = . . ~ . -.

VYNPS LIMITING CONDITIONS FOR OPERATION . SURVEILLANCE REQUIREMENTS returned to within.the prescribed limits' control rod pattern as described in the within two (2) hours,Lthe reactor.shall bases for Specification 3.3.B.6.

be brought to shutdown condition within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Surveillance. and corresponding action shall continue until-reactor operation is within the prescribed

' limits.-

180-b1