ML20090M717

Forwards Response to 840308 Request for Addl Info Re Requested Relief from Certain Requirements in ASME Code Section XI, Inservice Testing of Pumps & Valves. Appropriate Justification Provided

ML20090M717
Person / Time
Site:	Beaver Valley
Issue date:	05/17/1984
From:	Carey J DUQUESNE LIGHT CO.
To:	Varga S Office of Nuclear Reactor Regulation
References
TAC-49437, NUDOCS 8405290141
Download: ML20090M717 (12)

Text

1 o

.,e Tg5 Telephone (412) 393-6000 Nuclear Division P.O. Box 4 Shippingport, PA 15077-0004 May 17, 1984

/ rector of Nuclear Reactor Regulation United States Nuclear Regulatory Cm missicn Attn: Mr. Steven A. Varga, Chief Operating Reactors Branch No. 1 Division of Licensing Washington, DC 20555

Reference:

Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 IST Punps and Valves Gentlemen:

On February 14 through 17, 1984, Mr. Donald Caphton of your Region I office conducted an inspection of the Beaver Valley Power Station to review our request for relief frcxn certain requirements in ASME Code Section XI, Inservice Testing of Punps and Valves. As a result of this review, a Request for Additional Infonnation, dated March 8, 1984, was addressed to the Beaver Valley Power Station and responses are set forth in Attachttent "A". Attachment "B" repre-sents our requests for relief frcm ASME XI with appropriate justifications.

Very yours, J. . Carey Vice President, Nuclear Attachnent ec: Mr. W. M. Troskoski, Resident Inspector U. S. Nuclear Regulatcry Comnission Beaver Valley Power Station 3hippingport, PA 15077 U. S. Nuclear Regulatory Ccmnission c/o Document Managment Branch Washington, DC 20555 Director, Safety Evaluation & Control Virginia Electric & Pow r Company P.O. Bo 26666 One Janes River Plaza Richmond, VA 23261 .

' I 8406290141 840517 PDR ADOCK 05000334 G PDR

ATTACHMENT A ITIN 1 Inside and outside Recirculation Spray Punps Inside Punps: RS-P-1A and RS-P-1B Outside Punps: RS-P-2A and RS-P-2B Provide a description of your nodification proposals and the bases to show how these nodifications will enable wet testing during refueling cutages in accordance with requirements of ASME Section XI, Subsection IWP, to determine the hydraulic and mechanical characteristics and any degradation of these punps. NorE: If any relief is requested frm Subsection IWP for specific test require-ments or quantities, provide a technical basis for each request and a basis to show that the punps will be adequately tested to demon-strate their required levels of performance and safety function.

Response

Inside Pecirculation Spray Punps: RS-P-1A and RS-P-1B Beginning with the 4th refueling outage scheduled to begin in October 1984, the Inside Recirculation Spray Punps will be run in the recirculation mode every refueling outage.- In order to perform this test, the normal flow path will be blocked to prevent containment frm being sprayed. In addition, a tetporary dike will be installed around the containment sunp to prevent unnecessary flooding of containment. Since this test arrangement disables the recirculation spray system, this test can only be performed during refueling outages.

'Ihe proposed testing will measure all of the applicable quantities listed in Table IWP-3100-1 except for the observation of proper lubricant level. Tais observation will not be made since these punps are self-lubricated by the fluid being punped.

Due to maintenance activities and nodifications performed on the Recirculation Spray system since pre-operational testing,. new reference valves for the punps will be established in accordance with the code during the first inservice test.

We believe that this proposed testing will allow us to evaluate the hydraulic and mechanical characteristics of these punps and permit detection of punp degradation thereby fulfilling the intent of the code.

Outside recirculation spray punps are addressed in Attachment B, Its 1.

ITEM 2 (See attachment B)

T Attachnent A

.Page 2 ITEM-3 Valves to be Tested at Cold Shutdown and Befueling Provide a corrected list ' and correlation of old and new valve numbers for the feed water valves that have been renumbered.

Response

%e corrected list of . valves to be tested at cold shutdown and refueling includes the following valves:

1 % 622 1 N 623 1 N 624 1 % 625 1EW-626 1 M 627

%ese valves were installed under DCP 130. In March 1980,-when the relief request was sent to the NRC, it was thought that their mark

~

nunbers would be 1%387 through lEW-392. However, when they.were 2

installed, the Stone and Webster assigned nunters were used -

1 % 622 through 1 % 627.

3 ITEM 4 Valves Beauiring Pressure Isolaticn Verification

%e condition of each of the following valves is inportant to maintain redundant isolation capability and system integrity.

._ RH-720A PR-720B E 700 RH-701 SI-850B SI-850D SI-850F SI-10* SI-ll*

SI-12* SI-15 SI-16 SI-17 SI-20 SI-21

, SI-22 SI-23* SI-24*

SI-25* SI-48 SI-49 SI-50 SI-51 SI-52 SI-53 SI-83 SI-84

SI-100 SI-101 SI-102 CH-170 BC-556A PC-556B-I RC-556C f

• Isolation Valves Identified as Event V valves.

Ebr each of the listed valves, state whether or not full cmpliance with lW-3420, Valve leak ' Rate Test, is achieved, and, if not describe:

1. your alternate testing nethod and frequency for each valve, clearly demonstrating an acceptable seat leakage condition of

, the valve,

2. the leakage rate detection capability of the alternate method,

, 3. the permissible leakage rate,

4. the procedure to be used to analyze and cm pare with previous

. measursents, and,

~ Attachment A Page 3

5. the corrective action, if different frm IW-3420(g), to be taken if the individual valve leakage rates exceed the permissible leakage rates.

Ibsponse

'Ihe following valves are tested in full cmpliance with IW-3420.

[SI-10], [SI-ll], [SI-12], [SI-23], [SI-24], [SI-25]

'Ihese valves are the Event V valves identified by the station operating supervisor. As such, they are leak tested by OST 1.11.16, "Ieakage Testing ES Pressure Isolation Valves", which is in full empliance with subsection IW-3420 of the Code.

I [SI-48], [SI-49], [SI-50], [SI-51], [SI-52] and [SI-53] are tested in accordance with the code in full empliance with IW-3420 by OST 1.11.4, "Accunnlator Check Valve Test".

[SI-83] and [SI-84] are tested with water to 40.3 psig and since they are check valves, IW-3420(c) (5) permits them to be tested at lower differential pressure. 'Iherefore, these valves are tested in full cmphance with IW-3420 by BVP 1.3 - 1.47.11, " Safety Injection and Charging System Valve Ieak Test".

[G-170] is leak tested with water to 40.3 psig. 'Ihis valve -is a check valve, however, so full empliance with IW-3420 is achieved by BVP 1.3 - 1.47.11, " Safety Injection and Charging System Valve Ieak Test".

[MOV-BC-556A] , [W-E-556B] and [MOV-RC-556C] are in the fill 2 header frm the charging system to the reactor coolant systs.

'Ihese valves will be leak tested; however, the test method has not been empleted. 'Ihe test method and acceptance criteria will be ca plete October 1, 1984.

4 The following valves were reviewed to determine whether er not they perform a pressure isolation function. Our review indicates that these valves do not perform a pressure isolation function and are L not Cateogy A valves. Since these valves are not Category A, the leak requirements of 1HA 3420 do not apply.

[lOV-SI-850B], [MOV-SI-850D] and [MOV-SI-850F] are 3/4 inch I

normally closed valves in a test line. Because of their position in the test line, . IW-1300 excludes them fr m the testing requirments of the code. 'Iherefore, these valves will not be leakage tested. However, if they leak-by, a change in the accunulator pressure and level would be observed and the operator 4

would receive and alarm to indicate a changing condition.

,. [SI-15] , [SI-16] , [SI-17) , [SI-20] , . [SI-21] and [SI-22]

'Ibese check valves are not the boundary between high and low pressure systems. According to station drawings h 41A and h 41B,

the piping classification up and downstream of the valves is the same. It does not change until all the associated piping exits the containment. Furthermore, valve leak testing is performed on the associated redundant containment isolation' valves each refueling

- , y e ~ , n . - , ~ --

--r, -nm

Attachment-A Page 4 outage in accordance with 10CFR50, Appendix J, which is an acceptable alternative for the types of valves in question per IW-3420.

h refore, since [SI-15], [SI-16], [SI-17], [SI-20], [SI-21] and

[SI-22] do not act- as pressure isolation valves and the leak tests performed on the containment isolation valves provide confidence that pressure isolation capability is maintained, present Category C valve classification should be considered valid. As a result, these valves will not be leak tested to meet Category A requirements.

[SI-100], [SI-101] and [SI-102]

These check valves are not the boundary between high and low pressure systms. According to station drawings h 41A and RM-41B, the piping classification up and downstream of the valves is the same. Also, these valves are the second valves back frm the ICS.

The first valves in the system, [SI-23], [SI-24] and [SI-25], are leak tested in accordance with the code by OST 1.11.16, "Ieakage Testing RCS Pressure Isolation Valves".. Also included in the line are valves [SI-94] and (SI-95] which are leak tested every refueling in accordance with 10CFR50, Appendix J.

[SI-100], [SI-101] and [SI-102] are classified as Category C valves only and as such, they will not be leak tested to meet Category A requirements.

[MOV-RH-720A] , [10V-RH-720B] , [lOV-RH-700] and [MOV-RH-701]

'Ihese valves will not be leak tested since alternate methods for detecting leakage are available to verify valve integrity.

Currently continuous leakage pressure monitoring exists with Annunciator Al-125, "RHR Punp Discharge Pressure High" at a setpoint of 550 psig. Under normal plant operating conditions, this annunciator is not in the alarm state. 'Iherefore, any leakage past these valves would be monitored by the receipt of this alarm.

As added assurance to the continuous monitoring provided for by Annunicator Al-125, relief valve [RV-RH-721] with a setpoint of 600 psig would direct the discharge of any leakage to the Pressurizer Relief Tank (PRP) . If any leakage occurred, the amount would be indicated by a corresponding level increase in the PRT.

Further justification for these alternate metNds can be found in your previous approval of Relief Request 30 through 33 which classified these valves as ' Category B and the . staff guidance information_ previously provided which exenpts passive gate valves frm the testing requirements of Section XI. 'Iherefore, for these reasons cited, coupliance with IW-3420, Category A Valve Ieak Rate Testing, should not be rW for these valves.

ITDi 5 Event V Piping Configuration Beaver Valley, Unit No. 1 drawing % 38A, shows a piping interface where high pressure piping .is connecting with low pressure piping et 10-inch valves RH-720A and RH-720B. h low pressure piping

{.

c,- Attachment A' -

! ' Page;5 k

~ ~

', -(line 6"- RH-14-152) also leads outside of containment to the j1 refueling water. storage tank. 'Ihe ' high ' pressure piping side of i valves RH-720A and BH-720B are each in series with a check valve

~

~

SI-52 and SI-53,.respectively, and a cold leg of the reactor.-

p i - 'Ihe piping configuration described above matches the criteria L designated by the NRC as an Event V piping ccnfiguration, i.e., the F primary molant. system connects to a high pressure check valve, a i* motor operated valve - and . to low pressure piping that eventually leads ' outside of containment. . Refer' to . Event V piping

! - configurations described in Section 2.0 of the TER dated October '

i 24, 1980, an enclosure to the order, S.A. Varga to C. N. Dunn dated 1

t April 20, 1981.-

Provide any technical basis . you may have to justify excluding 7

coverage of the Event V piping configuration- fr m Technical Specification Table 4.4-3, where the high pressure piping interface at valves RH-720A and' RH-720B connects with ~ low pressure piping

that runs to the refueling water storage tank.

i j' Response 1 In order- to evaluate this configuration, additional reviews

[ describing the Event V piping ' configuration were performed.

i Included was the Reactor Safety Study '(RSS), - (WASH 1400), the

, original request that licensees evaluate for Event'V configurations dated February 23, 1980 and paragraph 2.0 ; of the Technical.  ;

D Evaluation Report (TER) dated GeLuber . 24, 1980 which was attached j to our Order of April' 20,1981.

,I 'Ihe TER provided additional exanples . of configurations. with specific criteria to determine if an ~ Event- V arrangenent exists.

'Ihe TER did not provide any further description' of the = Event 'V F failure mechanics or provide sufficient detail to evaluate

!_ downstream piping and its potential for transferring radioactive i naterials outside'of containment. - NASH 1400 addresses the failure i of check valves that isolate low pressure _ piping frm the reactor.

coolant systan (RCS).

~

'Ihis event requires nultiple failures to-occur :in the form of the' failure of. both -in-series check valves.

'Ihe RSS also' assumes the low pressure ' piping to fail ate a point outside containment 2 resulting ?in a ' direct path for radioactive release to atmosphere, i thus bypassing - the radinaetivity removal L i systems. . Ihe February 23,:1980' letter- to all licensees further i

. describes this event as possibly including :a locked open : n,

[ outside containment,:with the' high pressure-low pressure interface' j existing at the' downstream side of the M . In this configuration,'

the multiple failure _ of the check. valves leads to a direct' path.

~

outside contairment . to ^ low pressure piping . and the : leakage - path l cannot be isolated because the M is locked open.

We -have reviewed the piping configuration dimmaad above in your item . 5 ' to determine if it' meets the . Event . _V

configuration. Based

.cn the background information contained in the source dar,= ants, .

WhSH 1400 and the February 23,:1980 letter,'we have concluded that.

1 this is not' an Event V _ piping configuration'. While the1 series arrangementD of- SI-52 with p-RH-720A and SI-53 with p-RH-720B m-A w e- e - - , gr-.".w w. -- 3- f- riu = , w as g ==+1 3-=9-'g- *- ,e>'+ y -t.m- .py ye ?--*eg y9 .-

t~'*P T T'N' '""""

Attachment A Page 6 are similar to the configuration given in the TER, they are not the ,

same since each MOV is in the closed position with power renoved frm its motor operator during power cperation. Also, the M and the low pressure piping is inside containment and are protected frm overpressurization by a relief valve set to lift at 600 psig and the RHR punp seals. 'Ihis low pressure piping also has a closed manual isolation valve installed in the piping systan prior to the piping leaving containment. This overpressure protection results in potential releases frm the low pressure piping being contained within containment. 'Ihe cmbination of the closed MOV and the pressure relief path remaining inside containment prevents this configuration frm meeting the Event V definition.

To provide additional assurances on the integrity of the conponents, the following is presented for your consideration.

Both SI-52 and SI-53 are tested each refueling to determine leak tightness in accordance with the criteria given in ASME Subsection IW-3420. (See response to Item 4) Any leakage past the KN's would result in a gradual pressure increase of the low pressure piping which would be detected by the installed pressure switch which annunciates at 550 psig in the control rom. Due to the piping arrangment, the SI accumulators maintain approximately 600 psi between the SI check valves and the RHR KNs. This in effect represents in-situ pressure testing of the MOVs to 600 psig.

Finally, the containment isolation valve, RH-14, is tested in accordance with 10CFR50, Appendix J to determine if there is any valve leakage.

Therefore, we do not consider the subject piping arrangment as meeting the Event V configuration and adequate testing and the normal system characteristics represent sufficient means for determining the leak tightness of the subject valves. On this basis, it is not necessary to include these cmponents in Technical Specification Table 4.4-3.

ITEM 6 Additional Event V Piping Configurations Our review of your subnittal on Event V piping configuration has identified that your evaluation and response, as described in a C.

Dunn letter to D. Eisenhut dated March 17, 1980, was based upon Event V criteria provided in a D. Eisenhut letter to all IMR licensees dated February .42 , 1W0. However, the Event V identi-fication criteria was subsequently updated and sent to you by an NBC " Order for Modification of License Concerning Primary Coolant System Pressure Isolation Valves" dated April 20, 1981. Specif-ically, the updated Event V criteria was provided in paragraph 2.0 of the Technical Evaluation Report (TER), dated October 24, 1980, an attachnent to the order Describe the valve configurations at Beaver Valley Unit 1 based upon the criteria in paragraph 2.0 of the TER, and indicate whether additional Event V isolation valve configurations exist within. the class I boundary of the high pressure piping connecting primary  :

coolant system piping to low pressure system piping. You may l exclude frcm your response those piping configurations described in u

)

' Attachment'A  !

Page 7-your March 17, 1980 letter-and the TER, that are currently incor-

porated'in Technical Specification Table 4.4-3.

i' response

< 'Ihe prints of all-tha systems connected to the BCS were examined to determine if any. additional Event V valve configurations exist at BVPS. No other areas of concern were found.

4 h

4 t

f a

i e

- . . , - e,.. -

1 , , .- - - - . , . ,,.-

i A'ITACHMENT B ITIM 1 Inside and Outside Recirculation Spray Punps Inside Punps: RS-P-1A and RS-P-1B Outside Punps: RS-P-2A and RS-P-2B Provide a description of your modification proposals and the bases to show how these mtdifications will enable wet testing during refueling cutages in accordance with requirements of ASME Section XI, Subsection IWP, to determine the hydraulic and mechanical characteristics and any degradation of these punps. NOTE: If any relief is requested frcm Subsection IWP for specific test require-ments or quantities, provide a technical basis for each request and a basis to show that the punps will be adequately tested to demon-strate their required levels of performance and safety function.

Response

Outside Recirculation Spray Pumps: RS-P-2A and RS-P-2B Code Requirement:

An inservice test shall be conducted on all safety-related punps, naninally once each month during normal plant operation. Each inservice test shall include the measurement, observation, and recording of all quantities in Table IWP-3100-1, except bearing tenperature, which shall be nsasured during at least one inservice test each year.

Basis for Belief Regt.est:

Relief is requested fran the testing requirements of Section XI for the outside recirculation spray punps.

These punps are dry tested monthly for a maxinum of 60 seconds to verify operability by observing the punps have started when given a start signal. During this test, it is not possible to obtain the data required by subsection IWP. During refueling outages these punps are wet tested in the recirculation mode so that speed, inlet pressure, differential pressure, flowrote, vibration anplitude and bearing temperature can be measured. However,'due to the size of the recirculation line, the punps nust be shut dcnn to prevent punp overheating and punp damage before stable bearing tarperatures can be achieved. 'Ihe current testing is the only type possible under present plant design.

Additional methods have been evaluated to permic continued operation of these punps while testing during refueling outages.

We have concluded that in order to prevent punp overheating before stable bearing tepperatures can be achieved woulf. require increasing the size of the recirculation line. - At p cesent, ' the method of testing these ptmps (OST 1.13.7) , "Becirculation Pung Auto Start and Flow Test" provides sufficient information for the E _ _ , _ . _ .

. Rttachment B Page 2 determination that the purtps are capable of performing as designed by ccriparison with the pumps pre-determined characteristics. 'Ihis assures that no punp degradation has occurred. Since this determination can be made, the safety benefit gained through this modification would not justify the cost to implement this backfit.

It is therefore concluded that. the present methods of testing these punps are adequate for determining the hydraulic and mechanical characteristics and any degredation of these punps.

ITEM 2 Exercising of Check Valves Using Alternate Methods Check valves: ISI-48 ISI-5' 1SI-49 1SI-53 ,

1SI-50 1 p 197 1SI-51 1 % 198 Explain how your testing meets the Section XI, Subsect. ion IW 3410, Valve Exercising Test, cold chutdown requirements for each of the above listed valves. If a flow test is the method of test, provide information to show that the full design ficw is attained.

Response (ISI-48,1SI-49, ISI-50,1SI-51,1SI-52 and 1SI-53)

'Ihese valves are classified as category AC and are governed by subsections IW-3410 and IW-3520.

Code Requirenent 1W-3410 states in part:

" Valves shall be exercised to the position required to fulfill their function unless such operation is not practical during plant operation... Normally closed valves that cannot be operated during normal plant operation shall be specifically identified by the Gmer and shall be full-stroke exercised d.tring each cold shutdown.

Code Requirenent IW 3520 b states in part:

" Check valves shall be exercised to the rosition required to fulfill their function unless such operation is not practical during plant operation . . . Normally closed check valves that cannot be operated during normal plant operation shall be specif-ically identified by the Owner and shall be full-stroke exercised during each cold shut-down."

Subsection (2) of the above paragraph states:

" Valves normally closed during plant operation, whose function is to open on reversal of pressure differential, shall be tested by proving that the disk moves prmptly away frca the seat when the closing pressure differential is reoved and flow through the valve is initiated, or a mechanical opening force is applied to the disk."

^

y _7 -c , .. ; ' . . ;. 1

, s -

' .'- 4Attim L._d. B iPage 3' Basis ~for Relief Request:

Relief 'is requested _ from full-stroke exercising of these valves

.( ISI-48 through 1SI-53) for the following reasons: '1hese check valves are:in the discharge path of the SI Accunnlators to the cold -i legs. '1 heir function is to open and allow flow from the l acctmulator when the closing differential pressure is removed. OST  !

y 1.11.15, " Safety-Injection Acctmulator Check Valve Test" tests the i

function of these valves by creating a differential pressure and allowing flow. Successful empletion of this test verifies the

{J operability of these valves for performing their safety function.

l' In the Safety Evaluation Report performed by the NHC's contractor ,

I attached to the NRCs June : 29, 1982 letter it. was concluded that i I with the present piping configurations, only partial stroke

. exercising of these check valves is possible. However, we were to perform investigations of other methods for full-stroke exercising i of _these valves (e.g., manual exercising during refueling outages) .

Based .on our review, we have concluded that- the design of these

[ check valves will not- permit a manual ' full-stroke exercise test.

E Also, we have investigated disassenbly of these valves to verify -

full stroke capability. 'Ibese valvesEare installed in a high radiation area and represent considerable man-rm exposure for this type of examination, and . is therefore considered unameptable.

~

4 Also, in order to disassemble them valves would: require' draining

' of the BCS loops.. In the past, . maintenance activities have

necesciitated draining the loops to the mid-loop level which has

( resulted in occasional air binding of the' RHR ptmps. Our.present i criteria for maintaining adequate BCS loop levels for meeting NPSH

for the RHR I.unps will'not permit draining of the loops to a level' ,

i adequate to disassenble these valves for inspection plu.rr#s.

r In order to provide the ability to full-stroke exercise these j valves, either - manually or by providing new piping arrar.pents t i would require significant plant :nodifications. '1he present test i methods are considered: acceptable for determining operability of

thase valves.' As such, a plant backfit of this type is not -

considered an acceptable optim with respect to the safety benefit

1 inprovenent versus the cost of the nodification.

Response (1%197 and 1%198)-

1

=

'1hese valves are . classified as category- C and are goverend by J

Subcaction IW-3520' rather than 'IW 3410.

t Code Requirement IW 3520_ b states in part:,

2

" Check valves shall be ' exercised to. the: position required to

fulfill their function unless such operation-- is -not practical

during plant' operation . . -..' Normally- closed check valves that cannot be operated _during normal' plant- operation shall- be specif-i -ically identified' by the Owner and shall be full-stroke exercised ' .

l. during each cold shut h ."

l , subsection (2) of the above paragraph states:

-  ?

,mr . -. < - - .e em -m- e6+ ,4.w-- g, . . . . . . , -. --me- r.< .,e., w--o,-, ww.-e--ent-w--*= - - - - - - ,

i, .f..5ttachmentB 4

" Valves normally closed during plant operatim, whose function is to open on reversal of pressure differential, snall be tested by proving that the ' disk moves pronptly away frm the seat when the closing pressure differential is removed and flow through the valve

-is initiated, or a mechanical opening force is applied to the

' disk."

' Basis for Relief Request:

Relief is requested frm full-stroke exercising 'of these valves (1BN-197 and 1RN-198) for the following reasons: 'Ihese check valves are partial stroke exercised by a flow test monthly per OSTs 1.30.2, 3 and 6, " Reactor Plant River Water Punp Tests",

regardless of plant status. 'Ihe OSTs measure the flow just before it enters the recirculation spray heat exchangers. 'Ihe only path away fr m the~ heat exchangers is through the check valves which are in parallel non-isolable lines, therefore, the flow seen by both valves together is full design flow. With the present system design, the individual flow rate thru each valve cannot be verified. However, the above test does verify that at least one of the check valves open. In . order to verify the operation of both valves, we are evaluating a method of obtaining accoustic measurements during refueling outages.

With the above test modification, both valves will be verified to open at least partially. Experience with other valves of similar.

construction in river water lines has shown that partial stroking of these valves is sufficient to detect degradation. '!herefore, relief is requested fr m full stroke exercising these valves every refueling for the above mentioned rmanns.

Additionally, perforran of a flow test to determine if each valve-disc is stroked sufficiently to demonstrate the ability to pass the design flow rate was cx)nsidered. Due to the design'of the syste ,

it'is not possible to isolate flow through me check valve in order-

~

to verify full -design flow passing through the ' other valve. - In order to acccuplish this test, a ,nodification to the existing systs would have to be. performed. It was concluded that modifications to this syst s could not be justified. ,This is based on the successful ocupletion of the above referenced tests to=

demonstrate the ability of- the recirculation spray system to pass design river water. flow and our pwpuied evaluation for obtaining -

-accoustic measurements of flow through each ofEthese valves'duris; refueling outages. ' mis. action is adequate to acsure the systes ,

capability to pass : full- design- flow s and ~ therefore, any i

nodifications will not significantly increase assurance of this

system to fulfill 'its safety function and therefore are not i considered viable with respect =to the .backfit criteria ~in i

l evaluation of the benefit gained versus the cost for the modification.

i 1 I  !

i l

l ,

f i 'i I

I' i^ . .

, . . - - . , , _ , - . - . - - , - - , , - - , , - - - - . - .