ML20211E142

NRC Insp Manual Ti 2515/XXX, Operation of Dual Function Containment Isolation Valves

ML20211E142
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Issue date:	07/15/1997
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ML20211E074	List: ML20211E069 ML20211E142
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PROC-970715, NUDOCS 9709300049
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NRC INSPECTION MANUAL- SCSB TEMPORARY INSTRUCTION 2515/XXX  ;

i OPERATION OF DUAL FUNCTION CONTAINMENT ISOLATION VALVES it

--SALP FUNCTIONAL AREA: OPERATIONS (OPS)

APPLICABILITY: This Temporary Instruction (TI) is to be performed at the following PWR power reactor facilities: AN02. FARLEY. V0GTLE

• and CATAWBA.

2515/XXX-01 OBJECTIVES The objective of this Tl is to determine if the licensee has procedures in-place

• to remotely close the containment isolation valve whether or not a "Containmern ,

Isolation" or " Safety injection" signal is " sealed in" relative to the ESF function. This TI is issued for information gathering purposes.

2515/XXX-02 BACKGROUND 4

The safety system containment isolation philosophy for dual function containment isolation valves appears.to vary within the designs of operating plants. A clear discussion of the staff's position follows.

There are two possibilities for a dual function containment isolation valve, The system which contains the containment isolation valve can have either a non-safety or safety related function as a process- flow path but in both cases the

-containment isolation function would be safety related. For the non-safety related system, any signals generated for the system operation of the-flow path have-are non-safety related function and have no priority over a containment isolation signal. Therefore, when a containment-isolation signal is generated, it immediately overrides the system flow path signal and closes the containment isolation valve.

- For -the safety -_related systems, the process- flow path signals generated for-system op0 ration (i.e., in the. case of a ECC system, this would be a safety

injection signal) are safety related. Unlike a non safety related system, the safety system function does not cease when the need for containment isolation is 4

identi fied. The safety related process flow path function takes priority cter containment isolation function - As long as the system is able to aerform its safety function containment isolation should not be implemented. However. if

-the_ system is_not able to perform its safety function, then containment isolation becomes its number one priority.

' Issue Date: 07/15/97 2515/135

. :9709300049 970924' PDR' ORG NRRA PDR ,

.- _, __ - _.____.-. . . _ . . _ . _ . -. _ _ . . - ~ . . . _ . _ _ . . . _ ~

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-By having the safety system process flow path function take first priority the need for automatic containment isolation is deferred for that system. Remote manual-isolation is a normal mode for containment isolation in this type of system. G,ce it u determined that the safety function of the system or train is not operable, containment isolation becomes the number one priority for the

-containment isolation valve. The operator should have procedures and be trained to properly isolate the system which means closing both containment isolation valves is that system or train.

The requirements to isolate means that the function is normally fully safety grade. This means that the instrumentation, motive power, actuator, and valve is all safety grade. If the valve is motor operated, it should be Class 1E powered. For air power, the valve should either close upon loss of air supply or the supply should be considered essential which generally implies an adequately sized accumulator that will assure valve closure for at least 30 days.

To identify a dual functioning containment isolation valve, the valve would be listed as a containment isolation valve within the FSAR table of isolation valves. The dual function containment isolation would not receive a automatic containment isolation sijnal to close but would have remote manual operation in the control room listed in the FSAR table. The staff considers remote manual closure in the control room as fulfilling the containment isolation function for these dual function valves. However, the staff has recently become aware of the i fact that some plants with remote manual closure capability in the control room are not able to close the containment isolation valve when a safety injection signal is present.

As additional background information, attachment 1 contains a memorandum with -

more detailed information on a specific plant design and identified problem. The  !

information provided in this background section above and in the attachment 1 are not intended to be used as inspection criteria. This information is only provided to enhance the Mspector .nowledge only. The memorandum has been placed in the PDR and may be given to any interested party.

2515/XXX-03 INSPECTION REQUIREMENTS The following inspecticr requirements are intended to provide a guidance to resident inspectors to gather information to help identify a potential emerging issue related to dual function containment isolation valves. The Severe Accident and Containment Systems Branch developed the questions to identify specific concerns that may be indicative of: (1) The ability of the operator to close the containment isolation valve from the control room or (2) the ability of the operator to know what steps to take from outside the control room to close the o affected containment isolation valves. The resident inspector should ask these questions of the licensee. A "no" answer to any of the questions is a possible indication of a regulatory concern that may warrant further assessment. If a licensee provides a "no" answer to all of the questions below other than the first question or if you would like additional information regarding any of the questions, please contact Jack Kudrick at 301-415-2871 or Tony D'Angelo at 301-415-2857.

2515/135 Issue Date: 07/15/97

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03.01 Identify the' dual function valves as listed in-the FSAR. Please verify-with plant staff if other dual function valves exist in the plant. Please attach -

- copy ' Are differences noted from the FSAR? yes or no.

03.02 In the presence of a containment spray or safety injection signal to open the valve, can the valve be closed from the control room with a switch and remain closed? .yes or no.

03.03 If the answer to 03.02 is no, in the presence of a containment spray or safety injection signal to open - the valve. are there procedures which the operator can use to close the valve via other methods- (such as de-energizing circuits or lifting leads or installing jumpers) remote from the valve? yes or

- no. If yes provide a copy of the procedure.

03.04 If answers to 03.02 and 03.03_are no's, is there any other means that the licensee has to close the isolation valve.

2515/XXX-04 REPORTING REQUIREMENTS Document the results on attached form (Attachment 2) and please fax (301-415-3707) or mail to Jack Kudrick or Tony D'Angelo. OWFN. mail stop 0 8 H-7. If

.you have any questions, comments, or require additional information please call Jack Kudrick at 301-415-2871 or Tony 0' Angelo at 301-415-2857. Since this is an .

information gather TI for NRR. include a short paragraph of this inspection effort in a routine inspection report. The survey form should not be included in the inspection report.

2515/XXX 05 COMPLETION SCHEDULE ,

Within thirty days of issuance of the Tl 2515/XXX-06 EXPIRATION This temporary instruction will remain in effect until December 1. 1997.

2515/XXX-07 CONTACT Address questions concerning this TI to Jack Kudrick at 301-415-2871-or Tony D'Angelo at 301 415-2857.

2515/XXX-08 STATISTICAL DATA REPORTING Record Actual inspection time for this TI against 2515/XXX for RITS reporting.

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-- Issue Date: 07/15/97 2515/135

2515/XXX-09 ' ORIGINATING ORGANIZATION INFORMATION 10.-01 Oroanizational Resoonsibility. The Severe Accident and Containment-Systems Branch (SCSB) originated this temporary instruction.

10.02 Resource Estimate Estimated inspection effort for this TI is expected to take.20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> per site. ,

10,03 Followuo Insoection Use IP XXXXX for inspection followup to this TI.

2515/XXX TRAINING No special training is planned for the conduct of this temporary instruction.

END

'2515/135 Issue Date: 07/15/97 2

Attachment l' MEMORANDUM T0: William D. Beckner. Director Project Directorate IV-1 Division of Reactor Projects II/IV FROM: Carl H. Berlinger. Chief Containment Systems and Severe Accident Branch Division of Systems Safety and Analysis (0RIGINAL SIGNED BY CH Berlinger 4/10/97)

SUBJECT:

iASK INTERFACE AGREEMENT (TIA) - WATERFORD 3 REQUIREMENTS FOR THE CAPABILITY OF CONTAINMENT ISOLATION VALVES TO CLOSE TO MAINTAIN CONTAINMENT INTEGRITY (TAC NO. M97234)

.The p;rpose of this memorandum is to respond to a Region IV request dated November 13. 1996. The request was to review the licensee's position on compliince with the General Design Criteria for dual function (i.e..open safety function on a safety injection actuation signal and/or containment function to isolate the containment) air-operated containment penetration valves.

Before addressing the specific designs, one needs to understand the roles of a system safety function and containment isolation function. In general, a system which = penetrates containment has an important role to play in the overall o)eration of the plant. Some perform a safety function in a pre / post LOCA manner w1ile others are important to the overall operation of the plant. In either case, how2ver, the requirement to perform a containment isolation function is the same.

Containment isolation is always considered to be a safety function. The only remaining question is when the isolation function needs to be performed.

Let us reverse the order and first discuss the role of the containment isolation valves for a non-safety system. For this system class it is normally assumed.

that the need for the system function ceases when the need for containment isolation is identifiad. Receipt of a containment isolation signal will cause the containment isolation valves to eulomatically actuate. This satisfies the containment function while at the same time ending the normal functioning of the system.

The safety system containment isolation philosophy is quite similcr. The difference relates to the priority of the function. Unlike for a non-safety system, the safety system function does not cease when the need for containment 1 solation is identified. The safety function simply takes priority over containment isolation. As long as the system is able to provide

Contact:

J. Kudrick SCSB/DSSA 415-2871

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its safety function, containment isolation should not be implemented. However.

if the system is not able to perform its safety function, then containment isolation becomes its number one priority.

By having the safety system function take first priority eliminates the need for automatic containment isolation. Remote isolation is the accepted mode for this

- type of system. With remote isolation capability, however, comes the need to know when isolation is needed. This generally means leak detection and some means to determine system operability.

Once it is determined that the safety function is not operable, containment isolation becomes the number one priority. The operator is trained to pro isolate the system which means closing both containment isolation valves.perl Now let us look at the requirements to isolate. The function must be fully safety grade. This means that the instrumentation, motive power. actuator, and valve must be all safety grade. If the valve is motor operated, it should be Class 1E powered. For air power, the valve should either close upon loss of air supply or the supply should be considered essential which generally implies an adecuately sized accumulator that will assure valve closure for 30 cays.

Therefore, for systems with a dual requirement, the valves can ind probably will have a two position criteria. To satisfy the safety system function, the valve position should be open. However, to satisfy the containment isolation function, valve position should be closed. To simply look at the safety system function to establish valve position meets only half of the valve requirements.

Additionally, tc power the valve actuator with a non-safety air supply is unacceptable when the failure position is open since the containment isolation function cannot be satisfied.

With this brief background, one can now discuss the specific questions contained with the TIA request. Specifically. Region IV has identified the following questions:

OUESTION 1 Does the licensee comply with the requirements of Criterion 57 (i.e. do the containment spray and component cooling water containment penetration valves have a closed safety function? In particular, are the air-operated valve accumulators required to maintain the valves closed on a loss of non-safety related instrument air?

RESPONSE

The- valves in question have dual requirements. For the system safety function, the valves have an open function to assure the operability of the system when needed. However, the valves also have a containment isolation function when called upon. Under this sequence, the valves have a closed function. As discussed above, the system safety function has first pr_iority. Therefore the fcil open design is appropriate. But, the containment isolation function is equally important when the situation

3-calls for isolation, This means that the air supply should be safety grade

.to minimize the times when one loses the air supply to the valve which also loses the containment isolation function. The design needs safety accumulators to assure an air supply in the event of loss of non-safety instrument air. For this reason, it is unacceptable to have non-safety instrument air without a safety backup system.

QUESTION 2 Would similar valves for containment penetrations subject to the requirements of Criteria 55 and 56 also have a closed safety function for containment-isolation, even if. the position of greater safety of the valve is to open?

RESPONSE

All containment isolation valves subject to the requirements of Criteria 55 and 56 have a closed safety function. However. it is quite misleading to state that the position of greater safety of the valve is to open. These valves under discussion have a del requirement: performance of the system safety function and the containment isolation function. Each function is a separate responsibility. Therefore for the systen safety function, the position of greater safety is open. But for the contdinment isolation function, the position of greater safety is closed. Since the system function has first priority the valve should fail open upon loss of air. However, since the containment isolation position of greater safety is closed, the air supply should be as reliable as possible to minimize the probability of the loss of air. This is translated to mean safety grade.

QUEST 10!L3 1s the licensee required to have the capability of remote manual closure of the containment penetration valves with a safety injection actuation signal and/or containment spray actuation signal present?

RESPONSE

The simple response is yes. The licensee is required to be able to remotely close the valve at any time during- the transient. This is particularly important if the safety system has a burned in signal to stay open to maintain the safety system function. The solution is to design the logic such that a switch in the control room can be actuated to over ride this open signal. An example of such a design can be found on the containment isolation valves connected to an external recombiner. Normally the valves are in a closed position. To allow the recombiner to become operational. these valves must be opened even though there exists a containment isolation signal. This ove, ride logic eliminates the need to jum)er the connections within the control cabinet which would be necessary witlout this control logic.

Equally important to the ability to change valve position is knowing when Lto initiate containment isolation. Sufficient instrumentation should be

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.available to the operator for this purpose. This would include leak detection as well as sufficient discrimination to determine which system is leaking.

QUESTION 4 If the answer to Question 3 is yes, are manual actions an acceptable means of meeting this requirement?

RESPONSE

Manual action is an acceptable means for meeting this requirement. But, it should be remote manual and normally from the control room.

With respect to the acceptability cf the accumulators that exist within the plant, we are currently discussing this issue with the licensee. We will report

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. resolution in a future amendment.

DISTRLBUTION:

CPate' Docket Files SCSB r/f (2)

PDR t

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• A ATTACHMENT:2 SURVEY FORM-FOR DUAL FUNCTION-ISOLATION: VALES [

PLANT NAME:

INSPECTOR'S NAME:

i, PHONE #:  ;

+

PLEASE COMPLETE THE FOLLOWING-QUESTIONS.

03.01- Identify the' dual function valves as listed in the FSAR. -Please verify with plant staff if other dual function

.' valves exiot'in the plant. Please attach copy. 'Are differences

-noted from the FSAR? yes-or no.

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03'.02 In.the presence of.a containment spray-or safety

= injection' signal to open the valve, can the' CONTAINMENT ISOLATION valve be closed from the control room with a switch and remain closed? yes_or no.

03._03 If the answer to 03.0? is no, in the presence of a containment spray or safety injection' signal to open the valve, are'there procedures which the operator can use to close the

" valve via other' methods (such as de-energizing circuits or

= lifting leads or installing jumpers).. remote from the va.r.ve? yes

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or no. If yes, provide a copy of the procedure.

4 03.04 If answers'to 03.02 and 03.03-are no's,.is there any other means that the: licensee has to close the isolation valve?

.yes or no.

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L Please f ax : to :-(301-415-3707) or mail to Jack Kudrick or-Tony D'Angelo,; OWFN, mail step O-8-H-7.

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