ML20095D593

Proposed TS SRs 4.6.2.1.1.d & 4.6.2.1.2.b,extending Containment Spray & RHR Sys Nozzles Testing Period from 5 to 10 Yrs

ML20095D593
Person / Time
Site:	Sequoyah
Issue date:	12/08/1995
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20095D576	List: ML20095D573 ML20095D593
References
NUDOCS 9512130168
Download: ML20095D593 (8)

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i ENCLOSURE 1 PROPOSED TECHNICAL SPECIFICATION (TS) CHANGE SEQUOYAH NUCLEAR PLANT (SON) UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 1

(TVA-SON-TS-95-20)  !

LIST OF AFFECTED PAGES 4 Unit 1 3/4 6-16a Unit 2 i 3/4 6-16a i

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9512130168 951208 PDR ADOCK 05000327

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CONTAINMENT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

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By verifying, that on recirculation flow, each pump develops a differential pressure of greater than or equal to 143 psid at greater than or equal to 4750 gpm when tested pursuant to. R84'-

Specification 4.0.5. I

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

_ 1.- Verifying that each automatic valve in the flow path actuates I to its correct position on a Containment Pressure High-High test signal.

2. Verifying that each spray pump starts automatically on a 1

/c l Containment Pressure High-High test signal.

d. At least once Myears by performing an air or smoke flow test through each spray header and verifying each spray nozzle is-unobstructed.

4.6.2.1.2 Each RHR spray train shall be 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 p years by performing an air or smoke flow test through each spray header and verifying each spray nozzle is unobstructed. ~'

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SEQUOYAH - UNIT 1 3/4 6-16a Amendment No. )////P f

80 i August 16, 1988 l

j CONTAI MENT SYSTEMS l

SURVEILLANCE REQUIREMENTS (Continued) n

b. By verifying that on recirculation flow, each pump develops a l differential pressure of greater than or equal to 143 psid at

' greater than or equal to 4750 gpm when tested pursuant to R71 Specification 4.0.5. ,

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c. At least once per 18 months during shutdown, by- 1 1' i

1. Verifying that each automatic valve in the flow path actuates

to its correct position on a Containment Pressure High-High

! test signal.

2. Verifying that each spray pump starts automatically on a

/0 Containment Pressure High-High test signal.

7 L d. Atleastonceper@yearsbyperforminganairorsmokeflowtest through each spray header and verifying each spray nozzle is unobstructed.

4.6.2.1.2 Each RHR Spray train shall be demonstrated OPERABLE:

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

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b. At least once per.Eyears by performing an air or smoke flow test _ through each spray header and verifying each spray nozzle is unobstructed.

SEQUOYAH - UNIT 2 3/4 6-16a Amendment No. /g 71 August 16, 1988

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ENCLOSURE 2 PROPOSED TECHNICAL SPECIFICATION (TS) CHANGE SEQUOYAH NUCLEAR PLANT (SON) UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 (TVA-SON-TS-95-20)

DESCRIPTION AND JUSTIFICATION FOR THE CONTAINMENT SPRAY / RESIDUAL HEAT REMOVAL (RHR) SYSTEMS NOZZLE SURVEILLANCE FREQUENCY REVISION

Description of Chanae TVA proposes to modify the Sequoyah Nuclear Plant (SON) Units 1 and 2 technical specifications (TSs) to revise Surveillance Requirements (SRs) 4.6.2.1.1.d and -

4.6.2.1.2.b to extend the testing period from 5 to 10 years. This change is consistent with the guidance provided in Generic Letter (GL) 93-05.

O Reason for Chanae ,

Performance of the spray nozzle surveillance requires draining of the piping leading to 4 the spray header. Since a small amount of watet may remain in the piping, there is a chance that this moisture may be ejected during the initial header pressurization through the nozzles. This could result in a contamination hazard. Another potential problem involves personnel safety. The test personnel manipulate the infrared camera

from the top of the polar crane. The polar crane is over 100 feet from the reactor cavity floor. Additionally, this TS surveillance extension is estimated to sase SON approximately $126,000over the life of the plant. .

Justification for Chanaes The containment spray (CS) system is designed to prevent the containment pressure, during a large break loss-of-coolant accident, from exceeding its maximum design pressure. The CS system performs this function by spraying borated water through spray he::ders at the top of the containment building. The cooler spray water condanses the steam in the containment atmosphere. If additional cooling is needed, the RHR system contains two spray headers that can be aligned manually.

For the systems to operate correctly, the nozzles in the spray headers cannot be blocked. SON presently tests these nozzles every five years using hot air. The purpose of this test is to identify any degradation of the spray headers that will prevent flow through the spray nozzles.

i NUREG-1366 indicates that operating history was reviewed to determine the success of the surveillance tests performed at various plants. Of the many tests reviewed, only three tests indicated nozzle flow problems. These three problems were construction related and not due to header degradation. GL 93-05 further warns of other considerations if the piping used is carbon steel.

At BON, there have been no problems identified during testing of nozzles for unchstructed flow; therefore, the proposed change is compatible with the operating experience discussed in NUREG-1366. Additionally, the proposed change is consistent with GL 93-05. CS subsystem piping that is in contact with borated water is austenitic stainless steel.

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i Environmental Imoact Evaluation The proposed change does not involve an unreviewed environmental question because ,

operation of SON Units 1 and 2 in accordance with this change would not:  !

1. Result in a significant increase in any adverse environmentalimpact previously '

evaluated in the Final Environmental Statement (FES) as modified by NRC's testimony to the Atomic Safety and Licensing Board, supplements to the FES, environmentalimpact appraisals, or decisions of the Atomic Safety and Licensing -

Board.

2. Result in a significant change in effluents or power levels.

3. Result in matters not previously reviewed in the licensing basis for SON that may have a significant environmentalimpact.

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ENCLOSURE 3 PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCLEAR PLANT (SON) UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 (TVA-SQN-TS-95-20)

DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION FOR THE CONTAINMENT SPRAY / RESIDUAL HEAT REMOVAL (RHR) SYSTEMS NOZZLE SURVEILLANCE FREQUENCY REVISION

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Significant Hazards Evaluation i.

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_TVA has evaluated the proposed technical specification (TS) change and has 1 determined that it does not represent a significant hazards sonsideration based on j- . criteria established in 10 CFR 50.92(c). Operation of Sequoyah Nuclear Plant (SON) in accordance with the proposed amendment will not:

1. Involve a significant increase in the probability or consequences of an accident

j. / . previously evaluated.

The TS change is consistent with the guidance provided in Generic Letter 93-05.

Containment spray (CS) systems' header piping is stainless steel; therefore, 4

corrosion will be negligible during the extended surveillance interval. Since the CS systems' headers are maintained dry, there is no mechanism that could cause blockage of the spray nozzles. Therefore, the nozzles in the CS systems will -

. remain operable, during the 10-year surveillance interval, to mitigate the Q . consequence of an ac'cident previously evaluated. Additionally, clogging or blockage has not been observed during the 5-year surveillance tests that have i

.been performed in the past at SON. Testing the CS systems' nozzles at the )

proposed reduced frequency will not increase the probability of occurrence of a . j postulated accident or the consequences of an accident previously evaluated. I i

2. Create the possibility of a new or different kind of accident from any previously analyzed.

l The proposed reduced frequency testing of the CS systems' nozzles does not  !

change the manner in which these systems are operated. The reduced testing l frequency of the spray nozzles does not generate any new accident precursors. j Therefore, the possibility of a new or different kind of accident previously evaluated is not created by the proposed changes in surveillance frequency of the CC systems' nozzles.

3. n ve a significant reduction in a margin of safety.

- Reduced testing of the CS systems' nozzles does not change the way the systems are operated or the systems' operability requirements. In this  ;

application, any additional corrosion of stainless steel piping will be negligible I during the extended surveillance interval. Since the CS systems are maintained  ;

dry, there is no additional mechanism that could cause blockage of the nozzles. l Therefore, the proposed reduced testing frequency is adequate to ensure spray l nozzle operability. The surveillance requirements do not affect the margin of safety since the operability requirements of both the CS systems remains unchanged. The existing safety analysis remains bounding. Therefore, there is ~

no reduction in the margin of safety. l

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