ML20058J910

Proposed Tech Specs Removing Requirement to Perform Jet Pump Integrity & Operability Surveillances in Idle Loop During Operation W/One Recirculation Pump

ML20058J910
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	12/06/1993
From:	VERMONT YANKEE NUCLEAR POWER CORP.
To:
Shared Package
ML20058J904	List: BVY-93-134, Application for Amend to License DPR-28,proposing Changes to TS by Removing Requirement to Perform Jet Pump Integrity & Operability Surveillances in Idle Loop During Operation W/One Recirculation Pump ML20058J910
References
NUDOCS 9312140302
Download: ML20058J910 (5)

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- ATTACHMENT A

- PROPOSED SPECIFICATION CHANGES I

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9312140302 931206 PDR ADOCK 05000271 P PDR  ;;.

tTYNPS 3.6 LIMITIl1G COtIDITIQ1 EUR OPERATIOi 4.6 SURVEILLAtCE RDQUIREMErfI' F. JetI W F. Jet Ptunps

1. Whenever the reactor is in the startup/ hot 1. Whenever there is recirculation flow with standby or run modes, all jet pumps shall the reactor in the startup/ hot stawJby be intact and all operating jet pumps shall or run modes, jet pump integrity and oper-be operable. If it is determined that a ability shall be checked daily by verifying that the following two conditions do not jet pump is inopereble, an orderly shutdown occur simultaneously:

shall be initiated and the reactor shall be in a cold shutdown condition within 24 The recirculation pornp flow dif fers hours, a.

by more than 10% from the established speed-flow characteristics.

b. The indicated total core flow is more than 10% greater than the core flow value derived from established power-core flow relationships.

2. Flow indication from each of the twenty jet 2.

In the event that the Jet pump (s) fail the tests punpa shall be verified prior to initiation in Specifications 4.6.F.1.a and .b, determine of reactor startup from a cold shutdown their operability by venfy,ng i that each condition. individual jet pump aP% deviation from average loop aP does not vary from its normal established

3. The indicated core flow is the sum of the deviation by more than 10%

flow indication from each of the twenty jet punps. If flow indication failure occurs 3. The surveillance requirements of 4.6.F.1 and .2 for two or more jet punps, ininediate cor- do not apply to the idle loop and associatel jet rective action shall be taken. If flow in- pumps when in single loop operation.

dication for all but one jet punp cannot be obtained within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> an orderly shut-down shall be initiated and the reactor 4. The baseline data required to evaluate the conditions shall be in a cold shutdown condition with- in Specifications 4.6.F.1 and 4.6.F.2 shall be in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. acquired each operating cycle. Baseline data for evaluating 4.6.F.2 while in single loop operation shall be updated as soon as practical after entering single loop operation.

Amendment tio. Q , # , M 109

VYN P.$

3.6 LIMITING CONDITION FOR OPERATION 4.6 SURVEILLANCE REQUIREMENT

' l G. S_ ingle _ Loop _Operellon G. Single. Loop 9per.a.tipo

1. The reactor may be started and operated or L. With one recirculation pump not in operation, core flow between 34% and 45% of rated, and operation may continue with a single recirculation loop provided that: core tharmal power greater than the limit specifleu in Figure 3.6.4 (Region 2),

a. The designated adjustments for APRM flux establish baseline APRM and LPRMII) neutron scram and rod block trip settings flux noise levels prior to entering this (Specifications 2.1. A.1.a na

• 2.1.B.1, region, provided that baseline values have Table 3.1.1 and Table 3.2.51, rod block not been established since the last core monitor trip setting (Table 3.2.5), MCFR refueling. Baseline values shall be fuel cladding integrity safety limit established with one recirculation pump not (Specification 1.1.A), and MCFR in operation and core thermal power less than operating limits and MAPLHGR limits, or equal to the limit specified in Figure provided in the Core Operating Limits 3.6.4.

Report, are initiated within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

During the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, either these ,

adjustments must be completed or the reactor brought to Hot Shutduwn.

b. With one recirculation pump not in operation, core thermal power greater than the limit specified in Figure 3.6.4, and core flow between 34% and 45%

of rated (Region 2 of Figure 3.6.4):

(1) Detector Levels A and C of one LPRM string per core octant plus detector Levels A and C of one LPRM string in the center of the core shall be monitored.

110 AmendmentNo.29,f4,//g

i UYNTS ,

3.6 L 4 (CONT *D)

The type of inspection planned f or each component depends on location, accessibility, and type of expected defect. Direct visual exemination is proposed wherever possible since it is sensitive, fast, and reliable. Magnetic particle and liquid penetrant inspections are planned where practical, and where added sensitivity is required. Ultrasonic testing and radiography shall be used where defects can occur on concealed surfaces.

The in-service Inspection and testing programs presented at this time are based on a thorough evaluation of present technology and state-of-the-art inspection and testing techniques.

In del _Eumpa Failure of a jet pump nozzle assembly hold down mecharism, nozzle assembly and/or riser, would increase the cross-sectional flow area for blowdown following the design basis double-ended line break. Theref- , if a failure occurred, repairs must be made.

1 The following f actors form the basis for the surveillence requirements:

A break in a jet pump decreases the flow resistance characteristic of the external piping loop causing the recirculation pump to operate at a higher flow condition when compared to previous operation.

The change in flow rate of the failed Jet pump produces a change in the indlested flow rate of that pump relative to the other pumps in that loop. Comparlson of the data with a normal relationship or pattern provides the indication necessary to detect a failed Jet pump.

The jet pump flow deviation pattern derived f rom the diffuser to lower plenum dif ferential pressure readings will be used to further evaluate jet pump operability in the event that the jet pumps fail the tests in Specifications 4.6.F.1.a and b.

Amendment No. ff , [(I 123

9 YTNPS .

3.6 & 4.6 (continued)

Agreement of indicated core flow with established power-core flow relationships provides the most

' assurance that recirculation flow is not bypassing the core through inactive or broken jet pumps.

This bypass flow is reverse with respect to normal jet pump flow. The indicated total core flow is a summation of the flow indications for the twenty individual jet pumps. The total core flow measuring instrumentation sums reverse jet pump flow as though it were forward flow (except in the case of single loop operation when reverse flow is subtracted from the total jet pump flow). Thus, the indicated flow is higher than actual core flow by at least twice the normal flow through any backflowing pump. Reactivity inver*ory is known to a high degree of confidence so that even if a jet pump failure occurred during a shutdown period, subsequent power ascension would promptly demonstrate abnomal control rod withdrawal for any power-flow operating map point.

A nortle-riser system f ailure could also generate the coincLdent f allure of a je e 3 body; however, the converse is not Ltve. The lack of any substantist stress in the jet pump body mak e f ailure impossible without en initiat nozzle-riser system failure.

124 Amendment No. 29, 92, f/

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