ML20238B689

Proposed Tech Specs,Revising Wording of Jet Pump Operability Surveillance to Required Balanced Drive Flow Rather than Equal Flow Control Valve Position

ML20238B689
Person / Time
Site:	LaSalle
Issue date:	08/24/1987
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML20238B678	List: ML20238B675 ML20238B689
References
3485K, NUDOCS 8709010350
Download: ML20238B689 (10)

Text

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ATTACHMENT B a

PROPOSED CHANGES TO

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THE TECHNICAL SPECIFICATIONS FOR ,

OPERATING LICENSES NPF-11 AND NPF-18 l

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REVISED PAGES:

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l NPF-ll NPF-18 3/4 4-2 3/4 4-3 l B 3/4 4-1 B 3/4 4-1 .I 1

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P DOCK 05000373 PDR 1

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i REACTOR COOLANT SYSTEM i JET PUMPS . f LIMITING CONDITION FOR OPERATION

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3.4.1.2 All jet pumps shall be OPERABLE. $i APPLICABILITY: OPERATIONAL CONDITIONS 1 and 2.  !

ACTION:

s With one or more jet pumps inoperable, be in at least HOT SHUT 00WN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

SURVEILLANCE REQUIREMENTS 4.4.1.2.1 Each of the above required jet pumps shall be demonstrated OPERABLE  ;

prior to the THERMAL POWER exceeding 25% of RATED THERMAL POWER and at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by measuring and recording each of the below specified l parameters and verifying that no two of the following conditions occur when both recirculation loops are operating at the :=: fi:n ::ntr:1 :h: p::ithn.

ws% botsnced Flov).

a. The indicated recirculation loop flow differs by more than 10% from the established flow control valve position-loop flow characteristics for two recirculation loop operation. ,

b. The indicated total core flow differs by more than 10% from the established total core flow value derived from either the:

1. Established THERMAL POWER-core flow relationship, or Mjferential

2. Established core plate i .:t:nt h i pressure-core flow relation-ship for two recirculation loop operation.

c. The indicated diffuser-to-lower plenum differential pressure of any I individual jet pump differs from established two recirculation loop operation patterns by more than 10%.

4.4.1.2.2 During single recirculation loop operation, each of-the above required jet pumps shall be demonstrated OPERABLE at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by verifying that no two of the following conditions occur:

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a. The indica recirculation loop flow in the operating loop differs by more a 10% from the established single recirculation flow control va ve position-loop flow characteristics.

b. The indicated total core flow differs by more than 10% from the established total core flow value from single recirculation loop ow measurements 8'ejerived from e,#,er +4e:

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c. The indicated diffuser-to-lower plenum differential pressure of any individual jet pump differs from established single recirculation loop operational patterns by more than 10%.

LA SALLE - UNIT 1 3/4 4-2 Amendment No.

I 3/4.4 REACTOR COOLANT SYSTEM BASES j l

3/4.4.1 RECIRCULATION SYSTEM j Operation with one reactor core coolant recirculation loop inoperable has 3, been evaluated and been found to be acceptable provided the unit is operated j!

in accordance with the single recirculation loop operation Technical Specifi- )l cations herein. # '

An inoperable jet pump is not, in itself, a sufficient reason to declare a recirculation loop inoperable, but it does present a hazard in case of a design-basis-accident by increasing the blowdown area and reducing the capability of reflooding the core; thus, the requirement for shutdown of the l facility with a jet pump inoperable. Jet pump failure can be detected by l monitoring jet pump performance on a prescribed scheduled for significant degradation I N N O . Recirculation loop flow mismatch limits are in compliance with the ECCS LOCA analysis design criterion. The limits will ensure an adequate core flow coastdown from either recirculation loop following a LOCA. Where the recircu- ]

lation loop flow mismatch limits can not be maintained during the recirculation i loop operation, continued operation is permitted in the single recirculation loop operation mode.

In order to prevent undue stress on the vessel nozzles and bottom head region, the recirculation loop temperatures shall be within 50 F of each other prior to startup of an idle loop. The loop temperature must also be within -

50 F of the reactor pressure vessel coolant temperature to prevent thermal shock to the recirculation pump and recirculation nozzles. Since the coolant in the bottom of the vessel is at a lower temperature than the water in the upper regions of the core, undue stress on the vessel would result if the temperature difference was greater than 145 F.

The possibility of thermal hydraulic instability in a BWR has been inves-tigated since the startup of early BWRs. Based on tests and analytical models, it has been identified that the high power-low flow corner of the power-to-flow map is the region of least stability margin. This region maybe encountered during startups, shutdowns, sequence exchanges, and as a result of a recircula-tion pump (s) trip event.

To ensure stability, single loop operation is limited in a designated restricted region (Figure 3.4.1.1-1) of the power-to-flow map. Single loop 4 operation with a designated surveillance region (Figure 3.4.1.1-1) of the i power-to-flow map requires monitoring of APRM and LPRM noise levels.

3/4.4.2 SAFETY / RELIEF VALVES The safety valve function.of the safety relief valves operate to prevent

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the reactor coolant system from being pressurized above the Safety Limit of 1325 psig in accordance with the ASME Code. A total of 18 OPERABLE safety /

relief valves is required to limit reactor pressure to within ASME III allowable values for the worst case upset transient.

Demonstration of the safety-relief valve lift settings will occur only.

during shutdown and will be performed in accordance with the provisions of Specification 4.0.5.

LA SALLE-UNIT 1 B 3/4 4-1 Amendment No 40 '

INSERT A q

1. Established THERMAL POWER-core flow relationship, or

2. Established core plate differential pressure-core flow relationship for two recirculation loop operation.

l INSERT B l

During dual loop operation, the jet pump operability surveillance should be performed with balanced drive flow (drive flow mismatch less than 5%) to ensure an accurate indication of jet pump performance.

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REACTOR COOLANT SYSTEM JET PUMPS I LIMITIMG CONDITION FOR OPERATION 3.4.1.2 All jet pumps shall be OPERABLE.

APPLICABILITY: OPERATIONAL CONDITIONS 1 and 2.

ACTION:

, With one or more jet pumps inoperable, be in at least HOT SHUTOOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, ,

i SURVEILLANCE REQUIREMENTS 4.4.1.2.1 Each of the above required jet pumps shall be demonstrated OPERABLE prior to THERMAL POWER exceeding 25% of RATED THERMAL POWER and at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by measuring and recording each of the below specified parameters and verifying that no two of the following conditions occur when both recircula- l tion loops are operating :t th: ::= f ht :: .tr:;' :h: p::it;;r.. l wi% hlured flow. l

a. The indicated recirculation loop flow differs by more than 10% from the established flow control valve position-loop flow characteristics for two recirculation loop operation.

b. The indicated total core flow differs by more than 10% from the ,

established total core flow value derived from either the:

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1. Established THERMAL POWER-core flow relationship, or

2. Established core plate differential pressure-core flow relationship for two recirculation loop operation.

c. The indicated diffuser-to-lower plenum differential pressure of afiy individual jet pump differs from established two recirculation loop

, operation patterns by more than 10%.

4.4.1.2.2 During single recirculation loop operation, each of the above required jet pumps shall be demonstrated OPERABLE at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by verifying that no two of the following conditions occur:

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a. The indica recirculation loop flow in the operating loop differs by more a 10% from the established single recirculation flow II control va ve position-loop flow characteristics.

b. The indicated total core flow differs by *more than 10% from the established total core flow value from single recirculation loop

.TNSERT c.A +i1ow measurementsfdenWd'fmm eiker Noe:

The indicated diffuser-to-lower plenum differential pressure of l any individual jet pump differs from established single recirculation loop by more than 10%.

LA SALLE - UNIT 2 3/4 4-3 dment No.

< 3/4.4 REACTOR COOLANT SYSTEM BASES 3/4.4.1 RECIRCULATION SYSTEM

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Operation with one reactor recirculation loop inoperable has been evaluated and been found to be acceptable provided the unit is operated in accordance with i  ;

the single recirculation loop operation-Technical Specifications herein.

An inoperable jet pump is not, in itself, a sufficient reason to declare a recirculation loop inoperable, but it does present a hazard in case of a design-basis-accident by increasing the blowdown area and reducing the capability of reflooding the core; thus, the requirement for shutdown of the facility with a jet pump inoperable. Jet pump failure can be detected by monitoring jet pump performance on a prescribed scheduled for significant degradation

.TNSERT 6 lecirculationloopflowmismatchlimitsareincompliancewiththeECCS LOCA analysis design criterion. The limits will ensure an adequate core flow coastdown from either recirculation loop following a LOCA. Where the retir-culation loop flow mismatch limits can not be maintained during the recir-culation loop operation, continued operation is permitted in the single recirculation loop operation mode.

In order to prevent undue stress on the vessel nozzles and bottom head region, the recirculation loop temperatures shall be within 50 F of each other j prior to startup of an idle loop. The loop temperature must also be within ,

50 F of the reactor pressure vessel coolant temperature to prevent thermal shock to the recirculation pump and recirculation nozzles. Since the coolant .

in the bottom of the vessel is at a lower temperature than the water in the  ;

upper regions of the. core, undue stress on the vessel would result if the

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temperature difference was greater than 145 F.

The possibility of thermal hydraulic instability in a BWR has been investi- l gated since the startup of early BWRs. Based on tests and analytical models, -

it has been identified that the high power-low flow corner of the power-to-flow l map is the region of least stability margin. This region may be encountered  ;

during startups, shutdowns, sequence exchanges, and as a result of a retircula-tion pump (s) trip event.

To ensure stability, single loop operation is limited in a designated j restricted region (Figure 3.4.1.1-1) of the power-to-flow map. Single loop t operation with a designated surveillance region (Figure 3.4.1.1-1) of the  !

power-to-flow map requires monitoring of APRM and LPRM noise levels.  !

3/4.4.2 SAFETY / RELIEF VALVES The safety valve function of the safety / relief valves operate to prevent the reactor coolant system from being pressurized above the Safety Limit of 1325 psig in accordance with the ASME Code. A total.of 18 OPERABLE safety /

relief valves is required to limit reactor pressure to within ASME III allowable values for the worst case upset transient.

j Demonstration of the safety / relief valve lift settings will occur only during shutdown and will be performed in accordance with the provisions of Specification 4.0.5.

LA SALLE - UNIT 2 B 3/4 4-1 Amendment No. [3

INSERT A

1. Established THERMAL POWER-core flow relationship, or

2. Established core plate differential pressure-core flow relationship for two recirculation loop operation.

INSERT B j During dual loop operation, the jet pump operability surveillance should be performed with balanced drive flow (drive flow mismatch less than 5%) to ensure an accurate indication of jet pump performance.

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ATTACHMENT C TECHNICAL SPECIFICATION CHANGE REQUEST LASALLE COUNTY STATION UNITS 1,and 2 NO SIGNIFICANT HAZARDS CONSIDERATION Commonwealth Edison has evaluated the proposed Technical Specification Amendment and determined that it does not represent a significant hazards consideration. Based on the criteria for defining a significant hazards consideration established in 10 CFR 50.92 operation of ,

LaSalle County Station Units 1 and 2 in accordance with the proposed amendment will not:

1) Involve a significant increase in the probability or consequences of an accident previously evaluated because:

l This proposed change of the Technical Specifications is an ,

administrative change to clarify the conditions necessary to perform the  !

jet pump operability surveillance and correct typographical errors.

2) Create the possibility of a new or different kind of accident from any accident previously evaluated because:

This proposed change of the Technical Specifications is an administrative change to clarify the conditions necessary to perform the jet pump operability surveillance and correct typographical errors.

3) Involve a significant reduction in the margin of safety because:

This proposed change of the Technical Specifications is an administrative change to clarify the conditions necessary to perform the jet pump operability surveillance and correct typographical errors.

Guidance has been provided in 51 FR 7744 (reference (c)), for the application of standards to license change requests for determination of the existence of significant hazards considerations. This document provides i

examples of amendments which are not likely considered to involve significant hazards considerations. This proposed amendment most clearly resembles example e(i) of those examples deemed not likely to involve a significant i

hazards consideration. It is purely an administrative change meant to clarify the requirements.

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1 This proposed amendment does not involve a significant relaxation of the criteria used to establish safety limits, a significant relaxation of the bases for the limiting safety system settings or a significant relaxation of the bases for limiting conditions for operations. Therefore, based on the guidance provided in Federal Register and the criteria established in 10 CFR 50.92(e), the proposed change does not constitute a significant hazards consideration. )

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l ATTACHMENT D TECHNICAL SPECIFICATION CHANGE REQUEST  ;

LASALLE COUNTY STATION UNITS 1 AND 2 GENERAL ELECTRIC REPORT EA5-59-0687 NSSS PERFORMANCE EFFECTS DUE TO USE OF BLACK FOX RECIRCULATION PUMP IMPELLER AT LASALLE UNIT 1 i

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