ML20206F672

Proposed Tech Specs Adding RHR Spray Requirements

ML20206F672
Person / Time
Site:	Sequoyah
Issue date:	04/08/1987
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20206F657	List: ML20206F652 ML20206F672
References
NUDOCS 8704140328
Download: ML20206F672 (9)

Text

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i CONTAINMENT SYSTEMS 3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS CONTAINMENT SPRAY SYSTEM LIMITING CONDITION FOR OPERATION

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APPLICABILITY: MODES 1, 2, 3 and 4+.

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j g With one4 containment spray p W inoperable, rest re the inoperable spray i  %., p'n to OPERABLE status within 72 hoyrs or be in 07 STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />; restore the inoperable spray ?.M^= to OP RABLE status within the gi i next 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in COLD S}lVT00WN within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

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SURVEILLANCE REQUIREMENTS i c, s 1.n e.u

4.6.2.1 Each /ontainment Jrpray .pt= shall be demonstrated OPERABLE

a. At least once per 31 days by verifying that each valve (manual, power operated or automatic) in the flow path that is not locked,

] sealed, or otherwise secured in position, is in its correct position.

b. By verifying, that on recirculation flow, each pump develops a discharge pressure of greater than or equal to 140 psig when tested i  !

pursuant to Specification 4.0.5.

c. At least onco per 18 months during shutdown, by

1. Verifying that each automatic valve in the flow path actuates to its correct positinn on a Containment Pressurr -- ligh-liigh test signal,

2. Verifying that each spray pump starts automatically on a Containment Pressur #->81gh liigh test signal.

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d. At least once per 5 years by performing an air or smoke flow test thrnuyh each spray header and verifying each spray nottle is M1 c b unobstructed.

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SEQUOYAll UNIT 1 3/4 6-16 Amendment No. 1' 8704140328 B70405 PDR ADOCK 05000327 p PDM

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l CONTAINMENT SYSTEMS i

3/4.6.2 OEPRESSURIZATION AND COOLING SYSTEMS CONTAINMENT SPRAY SYSTEM t L

i LIMITING CONDITION FOR OPERATION r

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4 APPLICABILITY: MODES 1, 2, 3 and 4 d yk s&) St"'T I

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with oneA:onta19 ment spray 4W inoperable, restore the inoperable spray j M*4  :,:::m to CPERABLE status within 72 nours or be in at least NOT STANDBY witnin the next 6 nours; restore tre inopersole spray @s to OPERABLE status 41 thin the nest 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in COLD SHUTOChN ilthin the following 30 nours, SURVE!LLANCE 4E00!9E4!4TS 1

l C 5 An..u 4.6,/.1 Eich /ontalsment / pray a shall ce demonstrated CPERABLE:

o At least once per 31 days by verifying that eacn valve (msnual, power operated or tutomatic) in tno ficw patn that is not locked sealed, or otnerwise secured in position, is in its correct positon.

D By serif / ing, that on recirculation flow, eacn pumo develoos a 1 Jischarge pressure of .ireater than or equal to 140 psig wnen tested  ;

l pursuant ta icectficat*cq 4.0.5. I

c. At least once per 18 montns during shutdown, by:

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). Verifying that enen nutomatic valve in the flow patn actuates to its carrect position on a Containment Pressure Hign-Hign I i test signal.

l 2, Verifying tnat eacn soray pump starts lutamatically on i Canttinment Pressure Hign Hign test signal.

At least ance per 5 ,oirs Dy performinij an at e or smone f t:w test 2,

through elan lorly helder and verifying dach spr3y noz:le it A M a.%Ld unon s t e t.c t d >J.

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SEGUCVAH UNII J 3/4 0'10

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3.6.2.1 Two independent trains of both the containment spray and residual heat removal spray shall be OPERAdLE with each train comprised of:

a. A Containment Spray train with:

1. One OPERABLE Containment Spray pump,  !

2. One OPERABLE Containment Spray heat exchanger,

3. An OPERABLE flow path capable of taking suction from the refueling water storage tank and transferring suction to the containment sump, and

b. A RHR Spray train with:

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1. One OFERABLE residual heat removal pump, .

2. One OPERABLE residual heat removat heat exchanger, and

3. An OPERABLE flow path capable of taking suction from the containment sump.

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! 4.6.2.2 Each RHR spray train shall t'e demonstrated OPERABLE:

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a. Per surveillance requirements 4.5.2.b.2 and 4.5.2.f.3;

b. At least once per 5 years by performing an air or smoke flow test through each spray header and verifying each spray nozzle is unolstructed.

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ENCLOSURE 2 PROPOSED TECHNICAL SPECIFICATION CHANGE I

SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 i

i DOCKET NOS. 50-327, -328

] (TVA SQN TS 87-03)

DESCRIPTION AND JUSTIFICATION FOR PROPOSED ADDITION OF RHR SPRAY REQUIREMENTS I TO SECTION 3/4 6.2 J

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DESCRIPTION OF CHANGE

This change revises section 3/4.6.2 on page 3/4 6-16 of units 1 and 2 technical specifications. Limiting Condition for Operation (LCO) 3.6.2.1 is revised to specifically require the operability of both trains of Residual 4

Heat Removal (RHR) spray. The associated action statement and surveillance requirements are revised accordingly. The applicability statement is revised i to exempt the operability requirements for the RHR Spray in Mode 4. The j existing surveillance requirement (SR) is expanded to clearly identify SRs for

both the RHR spray and containment spray (CS) trains. Additionally, two editorial changes are made to the action statement and SR 4.6.2.1.c of only i the unit 1 technical specifications.

REASON FOR CHANGE.

The Sequoyah Design Criteria and the Sequoyah FSAR state that one train of RHR spray is needed if a design basis LOCA has occurred and only one train of ,

J containment spray is available (assuming a single failure had disabled the other train of containment spray). While operability of both RHR trains during Modes 1, 2, and 3 is currently ensured by LCO 3.5.2, the applicable

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operability requirements for the RHR spray train should also be stated in 1 LCO 3.6.2 to establish consistency between the containment spray system

! requirements in the technical specifications and the requirements discussed in the Sequoyah Design Celteria and FSAR. The two editorial changes made in the unit 1 technical specifications will make the technical specifications consistent with the unit 2 technical specifications and the St'andard Technical _

Specifications for Westinghouse Pressurized Water Reactors, NUREG-0452, ~*

, Revision 5, (Draft).  :

JUSTIFICATION FOR CHANGE The proposed change does not compromise nuclear safety. The operation of the

, plant is not altered. The containment spray system for each unit at Sequoyah

! includes four spray headers. Two of these headers belong to redundant trains

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of containment spray. Each containment spray train has a dedicated pump and heat exchanger, and each train is capable of delivering 4,750 spa of spray.

Containment spray is automatically initiated upon the hi-hi containment

! pressure signal. The other two headers belong to redundant trairis of RHR j spray. A total of 2,000 gpm of RHR spray can be provided by either train of

! the RHR system. RHR spray can only be' initiated by manual valve

{ manipulations. The proposed revision will make the containment spray system

, requirements explicitly consistent with the plant's Design Criteria and FSAR.

j While the necessary operability requirements do exist cumulatively in the current technical specifications under LCOs 3.5.2 and 3.6.2.1, this change l will enhance the technical specifications by placing all of the containment spray system requirements in one LCo.

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l In Mode 4, the RHR system's primary function changes from emergency core

cooling to shutdown decay heat removal, and the RHR system technical j specification requirements and alignment change accordingly. The following

evaluation concludes that use of RHR spray will not be necessary in Mode 4.

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4 Assuming a cooldown rate of 500 F per hour, which is stipulated in the General Operating Instruction (COI) -3, " Plant Shutdown from Minimum Load to Cold Shutdown," it would take at least four hours to get from initial 0 0 shutdown (assume tave=550 F) to Mode 4 (maximum tave=350 F).

Per the Function Restoration Guideline, FR-Z, use of RHR spray is prohibited for at least an hour after the initiation of a LOCA. Based on the above, the earliest time for RHR spray initiation following a LOCA occurring in Mode 1 and Mode 4 is one hour and five hours af ter shutdown, respectively. A comparison of the decay heat rates given in the Sequoyah FSAR table 6.2.1-8 for one hour and five hours after shutdown shows that the decay heat rate at five hours is approximately 61 percent of the decay heat rate at one hour. Similarly, the operation of one train of containment spray alone provides 70 percent of the flow rate of one train of containment spray supplemented by one train of RHR spray. Since the decrease in the decay heat rate is greater than the reduction in the containment spray system's capacity, it is concluded that the spray provided by the RHR spray will not be necessary following a LOCA which is initiated in Mode 4. In addition, the amount of initial blowdown energy released in Mode 4 will be significantly less than a design basis event due to the lower prinary coolant temperature.

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i ENCLOSURE 3 PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2

, DOCKET NOS. 50-327, -328 (TVA SQN TS 87-03)  :

DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATIONS FOR PROPOSED ADDITION OF RHR SPRAY REQUIREMENTS TO SECTION 3/4 6.2 e

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SIGNIFICANT HAZARDS EVALUATION

1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

No. The proposed amendment makes the Limiting condition for Operation 3.6.2.1 regarding the containment spray system's requirements explicitly consistent with the Sequoyah Design Criteria and the FSAR design basis LOCA analysis. The Design Criteria and the FSAR state that one train of RHR spray is needed if a design basis LOCA has occurred and one train of containment spray is lost (single failure criterion). While the operability of the RHR spray has been assured by existing surveillance requirements in the technical specifications, these requirements will now be appropriately listed or referenced in the containment spray system section.

2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?

a No. The proposed amendment does not change the plant's design, procedures, or testing. Therefore, it will not create any new accidents.

3. Does the proposed amendment involve a significant reduction in a

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margin of safety? . _

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No. The proposed amendment can only enhance safety since it will make the technical specifications clearer in regard to the design requirements for the containment spray system. The margin of safety regarding containment integrity as provided for by the containment spray system is not affected.

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