ML20238D897

Proposed Tech Specs,Revising Surveillance Requirement 4.5.2.d.1 to Verify RHR Sys Isolation

ML20238D897
Person / Time
Site:	Sequoyah
Issue date:	08/05/1987
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20237H582	List: ML20237H579 ML20238D897
References
TAC-R00203, TAC-R00204, TAC-R203, TAC-R204, NUDOCS 8709110480
Download: ML20238D897 (5)

Text

.

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

DOCKET NOS. 50-327 AND 50-328 (TVA-SQN-TS-87-27)

LIST OF AFFECTED PAGES Unit 1 3/4 5-6 Unit 2 3/4 5-6 I

i

)

8 p

gr #

P

~

EMERGENCY CORE COOLING SYSTEMS (ECCS)

SURVEILLANCE REQUIREMENTS (Continued)

Valve Number Valve Function Valve Position

a. FCV-63-1 RHR Suction from RWST open

b. FCV-63-22 SIS Discharge to Common Piping open

b. At least once per 31 days by:

1. Verifying that the ECCS piping is full of water by venting the l ECCS pump casings and accessible discharge piping high points, and 1

2. 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.

c. By a visual inspection which verifies that no loose debris (rags, trash, clothing, etc.) is present in the containment which could be transported to the echtainment sump and cause restriction of the pump suctions during LOCA conditions. This visual inspection shall be performed:

1. For all accessible areas of the containment prior to establishing CONTAINMENT INTEGRITY,.and

2. Of the areas affected within containment at the completion of each containment entry when CONTAINMENT INTEGRITY is established.

d. At least once per 18 months by:

1. Verifying automatic isolation and interlock action of the RHR '

system from the Reactor Coolant System when the Reactor Coolant System pressure is above 45t> psig.

90o

2. A visual inspection of the containment sump and verifying that the subsystem suction inlets are not restricted by debris and that the sump components (trash racks, screens, etc.) show no evidence of structural distress or corrosion.

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

1. Verifying that each automatic valve in the flow path actuates to its correct position on a safety injection test signal and

• automatic switchover to containment sump test signal.

Gl l SEQUOYAH - UNIT 1 3/4 5-6 l

l

EMERGENCY CORE COOLING SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

_ Valve Number _

Valve Function Valve Position

a. FCV-63-1 RHR Suction from RWST open

b. FCV-63-22 SIS Discharge to Common Piping open

b. At least once per 31 days by: -

1. Verifying that the ECCS piping is full of water by venting the ECCS pump casings and accessible discharge piping high points, and

2. Verifying that each vaTve (manual, power operat.ed or automatic) in the flow path that is not locked, sealed, or otherwise ,

secured in position, is in its correct position.

c. By a visual inspection which verifies that no loose debris (rags, trash, clothing, etc.) is present in the containment which could be transported to the containment sump and cause restriction of the pump suctions during LOCA conditions. This visual inspection shall be performed:

1. For all accessible areas of the containment prior to establishing CONTAINMENT INTEGRITY, and

2. Of the areas affected within containment at the completion of each containment entry when CONTAINMENT INTEGRITY is established.

d. At least once per 18 months by:

1. Verifying automatic isolation and interlock action of the RHR system from the Reactor Coolant System when the Reactor Coolant System pressure is above GC4 psig.

1oo

2. A visual inspection of the containment sump and verifying that the subsystem suction inlets are not restricted by debris and that the sump components (trash racks, screens, etc.) show no evidence of structural distress or corrosion.

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

1. Verifying that each automatic valve in the flow path actuates to its correct position on a safety injection test signal and automatic switchover to containment sump test signal.

4 SEQUOYAH - UNIT 2 3/4 5-6

. A k ,. . . , v..[ ; i . ' l k

~~

EECLOSURE.2  !

PROPOSED TECHNICAL SPECIFICATION CHANCE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 (TVA-SQN-TS-87-27)

DESCRIPTION AND JUSTIFICATION FOR

": 7.Z ~ -~ T. REVISED _ REACTOR. COOLANT' SYSTEH (RCS) . PRESSURE' SETPOINT Description of Change ,

1 1

The proposed change will revise surveillance requirement 4.5.2.d.1 by changing the reactor coolant system (RCS) pressure from 750 psig to 700 psig for the purpose of verifying automatic isolation of the residual heat removal (RHR) system from the RCS. -

4 Reason for Change The Sequoyah Nuclear Plant (SQN) design criteria for the RHR system valves requires the suction valves from the RCS to automatically close at an RCS pressure of 700 psig. The Final Safety Analysis Report (FSAR) and current testing practice also agree with the design criteria. The proposed change simply makes the technical specifications consistent with the design criteria, the FSAR, and current instrument setpoint.

Justification for Change l The design of the RHR system includes two isolation valves (flow control valves {FCVs]-74-1 and 2) in series on the inlet line between the high-pressure RCS and the lower-pressure RHR system. Each isolation valve is interlocked with the valve in the suction line from the refueling water storage tank (RWST) and the containment sump isolation valves. The interlocks are used to prevent opening FCV-74-1 and -2 unless the containment sump isolation valves are fully closed and the RWST isolation valve is fully closed. This arrangement prevents the contents of the RWST )

from being inadvertently lost to the containment sump and ensures no reactor coolant is dumped to the containment sump during cooldown or RHR system operations.

These valves are also designed to close automatically upon receiving a high-pressure signal from the RCS (700 psig). The high RCS pressure interlock is used to protect the RHR system from overpressurizing. The interlocks are provided from redundant trained pressure switches. Also, the sensors to actuate these interlocks are supplied by different manufacturers to provide diversity in the redundant channels. j 1

The proposed change only revises the instrument setpoint value used in the i technical specifications (from 750 psig to 700 psig) to be consistent with the design and as-built configuration of the plant.

l i

ENCLOSURE 3 PROPOSED TECHNICAL SPECIFICATION CHANCES J

SEQUOYAH UUCLEAR PLANT UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 (TVA-SQN-TS-87-27) i DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATIONS SIGNIFICANT HAZARDS CONSIDERATIONS  !

1. Is the probability of an occurrence or the consequences of an accident previously evaluated in the safety analysis report significantly increased? -

No. The suction isolation valves from the RCS are interlocked for automatic closure at an RCS pressure of 700 psig. This function is 4 to protect the system from overpressurization. The proposed change only revises the technical specifications to be consistent with the  ;

design criteria and the FSAR. l

2. Is the possibility for an accident of a new or different type than evaluated previously in the safety analysis report created?

{

i No. The capability for RHR system isolation has not been changed. l The proposed change simply makes the technical specifications consistent with the design and as-built configuration of the plant.

No hardware changes or changes in testing requirements have been made.

{

3. Is the margin of safety significantly reduced? )

No. The proposed change is editorial in nature and does not effect 4 changes to plant equipment, operating setpoints or limits, or operating procedures. Therefore, the margin of safety has not been reduced.

J e

_ - _ _ _ - _ _ _ _ _ _ _ . _ _ _____m_____