ML20073P626

Forwards Supplemental Info for 910124 Application for Amend to License NPF-86 Re RHR Sys Isolation Valve Autoclosure Interlock Removal

ML20073P626
Person / Time
Site:	Seabrook
Issue date:	05/16/1991
From:	Feigenbaum T PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NYN-91079, NUDOCS 9105220145
Download: ML20073P626 (26)

Text

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1. New Hampshire Yk Ted C. Fe;genbovm Preddent and J

Chief Executive Officer i

NYN 91079 May 16,1991 United States Nuclear Regulatory Commission

- Washington,' D.C.

20555 Attention:

Document! Control Desk

References:

(a)

Facility Operating License No. NPF 86, Docket No. 50 443 (b)

.WCAP 11736A, " Residual lleat Removal System Autoclosure Interlock Removal Report for the Westinghouse Owner's Group", Revision 0.0, October 1989 (c)

NHY Letter NYN 91011 dated January 24,1991, " Request' for License Amendmer.t Residual Heat Removal System Isolation Valve Autoclosure Interlock Removal",- T.C. Feigenbaum to USNRC (d)

USNRC Letter dated April 16,1991, "Seabrook Proposal tc Remove Residual IIcat Removal (RHR) Autoclosure Interlock (TAC No. 79624)",

G; E. Edison to T. C. Feigenbaum

Subject:

Supplement to Request for License Amendment Residual Heat Removal System isolation Valve Autoclosure Interlock demoval

' Gentlemen:

New Hampshire Yankec 'NHY)_ has :nclosed herein supplemental information to its January 24, 1991, license.amendmc.4 ncest regarding the Residual lleat Removal System Isolation Valve Autoclosure Interlock Removal [ Reference (c)]. The _ following supplemental

'information is enclosed as requested by the USNRC Staff representatives'during conference calls with NHY personnel on March 26, March 28 and April 11,1991 [ Reference (d)].

Supplemental Response to NRC Staff Position 5 on WCAP-11730.

Supplemental Response to NRC Staff Position 4 on WCAP 11736.

Supplemental Information and No Significant Hazards Consideration for Proposed Changes to Technical Specification Surveillance Requirement 4.4.9.3.2 (Surveillance Frequency for RIIR Suction Isolation -Valves). -

Supplemental Information and No Significant Hazards Consideration for Proposed Changes to Technical Specification 3.4.9.3 (RHR Suction Relief Valve-Setpoint Change).

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PDR ADOCK 05000443 p

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New Hampshire Yankee Division of Public Service Company of New Hampshire 4

P.O. Box 300

• Seabrook, NH 03874

• Telephono (603) 474-9521 1hi c sl-77 i i o

.__.m United States Nuclear Regulatory Commission May 16,1991 Attention:

Document Control Desk Page two Should you_ require additional information regarding this matter picase -contact Mr, James M. Peschel, Regulatory Compliance Manage.r, at (603) 474-9521, extension 3772.

Very truly yours, ffGh f&hM- -- --

Ted C. Feigenbaum TCF:J MP/les Enclosure ec:

Mr. Thomas T Martin Regional Administrator United States Nuclear Regulatory Commission Region 1 475 Allendale Road King of Prussia, PA 19406 Mr. Gordon E. Edison, Sr. Project Manager Project Directorate 13 Division of Reactor Projects U.S. Nuclear Regulatory Commission Washington, DC. 20555 Mr. Noel Dudley NRC Senior Resident inspector P.O. Box 1149 Seabrook, NH 03874 Mr. George Iverson, Director -

N.H. Office of Emergency Management State House Office Park South 107 Pleasant Street

. Concord, NH 03301 l

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P New llampshire Yankee M ay - 16, 1991 ENCLOSURE I TO NYN-91079 SUPPLEMENTAL RESPONSE TO NRC STAFF POSITION 5 ON WCAP-11736

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The R11R suction valve onerator should be sized so that the valves cannot be opened against full system pres ute.

SUPPLEMENTAL RESPONSE New Ilampshire Yankee (NilY) attempted to confirm that the Residual lleat Removal-(RliR) inlet isolation valve motor operated actuators are incapable of opening the valves when the Reactor Coolant System (RCS) is at full pressure (2235 psig). The valves in question (RC-V22, RC V23, RC-V87 and RC V88) are included in our motor operated valve (hiOV) Program and are subject to established program controls and the normal hiOV operating practices. During MOV operation in the open direction, the actuator torque switch is bypassed until the valve is approximately 30% open.

This feature emures that the valves disc is unseated before engaging the actuator torque switch protective feature. Although these valves are not designed or tested to open against full system pressure, based upon our engineering judgement these valves potentially-could open against the RCS pressure of 2235 psig.

However, it _ can be stated that these valves by design cannot be opened at full RCS pressure due to the existence of the open permissive interlock. This redundant and diverse interlock prevents opening of the RHR inlet isolation valves when the RCS

- pressure is greater than or equal to 365 psig, in accordance with Technical Specification 4.5.2.d.1, this Open Permissive Interlock is tested on an eighteen month frequency. The RHR Autoclosure Interlock removal modification does not change the open permissive circuitry. Therefore, the open permissive interlock will prevent the valves from being opened with the RCS at pressure and, accordingly, sizing of the-l valve motor operators to preclude opening against full system pressure is not a design criteria for these valves. In addition to the open permissive interlock, administrative controls ensure that these valves are not inadvertently opened at full RCS pressure.

These administrative controls include procedural reguliements to close and remove power from the RilR suction isolation valves during startup prior to entering Mode 3.

The Seabrook Station RHR inlet isolation valves are located inside the containment and are Safety Class 1.

The code class break occurs after the second isolation valve and prior to the RHR suction relief valve which is also located inside the containment.

The Seabrook design is very similar-to that of the Callaway plant.

Simplified diagrams showing the Seabrook and Callaway configurations are provided as Figures 1 and 2 respectively.

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In order for an interfacing system LOCA to potentially occur the operators would have to fail to remove power from the valves, contrary to procedures, while

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concurrently the open permissive interlock fails and inadvertent open signals are applied to the vahes causing them -to open against full RCS pressure.-

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It is noted that the interfacing systems LOCA analysis included in WCAP 11736 (see Section-7.3) does not take credit for the inability of the motor operators to open the RHR suction isolation valves in Modes 1, 2, or 3.

Rather it was mentioned as a note of conservatism.

The conclusions of WCAP 11736 relative to interfacing systems LOCA frequencies is not affected by RilR suction-isolation valve actuator siring and its-ability or inability.to open valves at normal RCS operating pressures.

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'Where feasible, power should be removed from the RHR suction valves prior to their being leak checked [ plant specific}? :

SUPPLEMENTAL RESPONSE I

New Hampshire Yankee (NHY) does not believe that removing power from the RHR suction

' valves prior. to their being leak tested is beneficial to plant safety or plant operation as

-discussed below-i i

Operating procedures requite that the RHR suction valves be closed and power be removed prior to entry into Mode 3.

NHY does not remove power from the RHR suction valves

-prior to their being leak tested because the leak testing is normally performed in Mode 4

.5 or 6 and the tested RHR trains are. returned to service lsce (1), below). Leak testing the RilR suction valves prior to final RHR suction valve closure in the heatup sequence is consistent with Seabrook Station Technical Specifications which exempt the RHR suction valves from leak testing after each valve actuation [see (2),- below). The RHR suction valves are closed and power is removed prior to entering Mode 3 (e.g, exceeding 350'F) [see (3),

below). Adequate assurances that the RHR suction valves are closed with power removed, to preclude RHR overpressurization, is provided by control room valve open alarms and by the heatup sequence procedural requirements to close and remove power from the valves

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. prior to entering Mode 3.

Valve closure is verified by reliable position indication in the control room [see (4), below). Valve operator power removal is also indicated in the control room.

As-discussed below, NHY's procedures for performing the RHR suction valve leak test provides operational flexibility, in that leak testing may be performed prior to final RHR suctio'n valve closure in _the heatup sequence. After leak testing one train of RHR suction valves (RC V22 and RC V23 or RC V87 and RC V88) the tested RHR train is returned to service while the other train is being testeu. There is no safety benefit associated with removal of power from the valves being tested. This requirement would add procedural complexity and time associated with removing and restoring power supplies. The additional testing time is undesirable in that it is potentially decreases the availability of decay heat removal loops and decreases the availability of the RHR suction relief valves to assist the

. Cold Overpressure Mitigation System in mitigating a RCS pressure transient.

Leak testing of the RHR suction valves is normally performed prior to final RilR suction valve closure in the heatup sequence. Early performance of the leak test prior to entry into Mode 3 is desirable for the following reasons:

RCS temperature and pressures are lower, thus minimizing the personnel safety concerns associated with containing the leakage for measurement as required by this test.

If a ~ valve exhibits unacceptable leakage, the cooldown required to perform valve

. maintenance is minimized.

Technical Specification ~3.4.6.2 specifies the maximum allowable Icakage from the RHR suction valves to be 5 GPM.

-if 'the leak test were performed in Mode 3, the time required to perform the test could result in it being the critical path activity for entry into Mode 2.

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i estimated from previous experience that the leak test EX1804.047 requires 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> for both trains.

l (1)

RHR Suction Valve Leak Testine Procedure NHY performs leak testing of the RHR suction valves RC-V22 RC-V23, RC V87 and RC-V88 per procedure EX1804.047 (" Reactor Coolant Preisure isolation - Valve Leak Rate Testing'). EX1804.047 allows testing of the RHR suction valves "in Modes 3 through 6 and dier the RHR suction relief valve is no longer needed for LTOP protection

• EX1804.047 does not reouire that newer be removed from the RHR suction valve ooerators orior to the oerformance of the leak test. Upon completion of leak testing of each train of RHR suction valves, the procedure directs the " return of the valves to the original pretest lineup or per the direction of the Unit Shift Supervisor."

(2)

Technical Soccification 3!4 4,6 2.

RCS Pressure isolation Valve Leak Testinc Reauirements Technical Specification Surveillance Requirement 4.4.6.2.2 requires leak testing of RCS pressure isolation valves. Surveillance Requirement 4,4,6.2.2.d requires that the leak test be performed within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following valve actuation due to automatic or manual action or flow through the valve, however the RHR suction valves are exempted from this requirement.

(3)

RCS Heatuo Procedure NHY.'s procedure for "Heatup from Cold Shutdown to Hot Standby" (051000.01) requires that within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after entering Mode 3, but before entering Mode 2, the RHR suction valves be leak tested or verified to have been leak tested within the last 9 mon t hs.

Prior to entering Mode 3, with RCS temperature less than 350'F the RilR system is isolated from the RCS by closing the suction valves in each RHR train and removing power from the valve operators. RHR suction valve closure is verified by control room operators using reliable position indicating lights on the Main Control Board. Valve operator power removal is also indicated in the control room.

(4)

RHR Suction Valve Position Indication The position indication for these valves is provided from the motor operator limit switches.

l This configuration is considered reliable and repeatable for the following reasons:

The valve operator is stopped by operation of the closing torque switch, not the valve position limit switch, j

The valve position limit switches m gear driven not subject to drifting, and their settings are verified periodica!:y as part of the NHY Motor Operated Valve Diagnostic i

Test Program,-

The valve is closed under no-flow and low:RCS pressure conditions that result in low l

valve operating stresses. Valve mechanism failure that would cause a valve position-l limit switch to indicate closed without the valve disk being seated is highly unlikely, and i

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.- Position = indication is verified to be correct for' these valves by performance of position indication testing as required by ASME Section XI, Subsection IWV. (not greater than each' 24 months) l l

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ENCLOSURE 3 TO NYN 91079 SUPPLEMENTAL INFORM ATION AND NO SIGNIFICANT 11 AZARDS CONSIDER ATION FOR PROPOSED-CH ANGES TO TECHNICAL SPECIFICATION SURVEILLANCE R EOUIREMENT 4.4.9.3.2 (SURVEILLANCE FREOUENCY FOR RHR SUCTION ISOLATION VALVES I

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Currently Technic'al Specification Surveillance Requirement 4.4.9.3.2 requires the following:

4i4.9.3.2 Each RHR suction relief valve shall be demonstrated OPERABLE when the RHR suction relief valves are being used for cold overprmure protection as follows:

a.

For RHR suction relief valve RC-V89 1)

By verifying at least once per 31 days that RHR RCS Suction Isolation Valve RC V88 is open with power to the valve operator removed, and 2)

By verifying at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> that RC-V87 is open.

b.

For RHR suction relief valve RC-V24 1)

By verifying at least once per 31 days that RC V22 is open with power to the valve operator removed, and 2)

By verifying at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> that RC-V23 is open.

c.

Testing pursuant to Specification 4.0,5.

.The proposed change to TS SR 4.4.9.3.2 requires the following:

4.4.9.3.2 Each RHR suction relief valve shall be demonstrated OPERABLE when the RHR suction relief valves are being used for cold overpressure protection as follows:

For RHR suction relief valve RC V89 by verifying at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> a.

that RHR RCS suction isolation valves RC-VR7 and RC-V88 are open.

b.

For RHR suction relief valve RC,V24 by verifying at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> that RHR RCS suction isolation valves RC-V22 and RC-V23 are open.

c.

Testing pursuant to Specification 4.0.5.

The current TS SR 4.4.9.3.2 requires a verification that power is removed from RC-V88 and RC-V22. The current requirement to verify power is removed ensures that a single failure of the common pressure transmitter PT-403 for RC-V22 and RC-V87 or the common pressure transmitter PT-405 for RC-V23 and RC-V88 does not result in both trains of RHR being isolated from the RCS (see Figure 3).

't ne proposec TS SR 4,4.9.3.2 does not require the removal of power from any of the-RHR suction valves. With the disabling of the RHR Autoclosure Interlock (ACl) circuitry there is no mechanism for autoclosure of the RHR suction isolation valves which can result in both RHR trains being' isolated from the RCS (see Figure 4) and cencomitant loss. of 'RHR cooling.

1

i The proposed TS SR 4.4.9.3.2 also changes the surveillance frequency for verification that the RHR suction valves are open as follows:

from once per 31 days RC V22 to once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> RC-V23 from once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> RC V87 from once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> RC V88 from once per 31 days to once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> The proposed "2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> surveillance frequency for verifying that the RHR suction valves are open when N RHR relief valves are being utilized for RCS cold overpressure protection is identical to the surveillance frequency for verifying that the Power Operated Relief Valves (PORV) isolation valves are open when the PORV's.are being utilized for RCS cold overpressure protection (see TS SR 4.4.9.3.1 ).

The -same 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> open verification surveillance frequency and basis was provided for Callaway as stated in WCAP 11736 (see Section 8.2, pages 4 and 8-5 attached).

The 4 reposed reduction in the surveillance frequency for verifying that RC-V23 and RC-V87 are open (eg.12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />),

increase in the surveillance frequency for verifying that: RC-V22 and RC V88 are open (eg.

31.-days to 72_ hours), and climinating the requirement to verify that power is removed from the motor operators for RC-V22 and RC-V88 do not involve a significant hazards consideration pursuant to 10 CFR 50.92 as discussed below:

1.

The proposed change in the surveillance frequencies for verifying that the RilR suction isolation valves RC V22, RC V23, RC V87 and RC-V88 are open and

_ eliminating the requirement to verify that power is removed from the motor operators for RC-V88 and RC V22 does not involve a significant increase in the prooability or consequences of an accident previously evaluated.

The purpose of_ the surveillance requirement is to ensure that the RHR suction isolation valves remain open when-the RHR suction relief valves RC-V24 and RC-V89 are being used for RCS cold overpressure protection.

The current requirements to remove power from RC V22 and RC-V88 ensures that a -single component failure (pressure transmitter)-does not result in the isolation of both RHR trains from the RCS.

The disabling of the --RHR Autoclosure Interlock (ACl) circuitry eliminates the mechanism for autoclosure of the RHR suction isolation valves, thus the r: quirement to remove power from the valve operators is unnecessary and undesirable because the ability to expeditiously isolate the-RHR system from the RCS is precluded in the event of an RHR system-LOCA.

The proposed.72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> surveillance frequency for verifying that RC-V22, RC-V23, RC-V87 and RCV 88 are open when the RHR suction relief valves are being utilized for RCS cold overpressure protection is identical to the surveillance frequency for verifying that the Power Operated Relief ' Valves 2

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(PORV) isolation valves are open when the PORV's rire being utilized for RCS cold overpressure protection. As stated above, the disabling of the RllR ACI circuitry eliminates the mechanism for autoclosure of the RilR suction isolation valves, thus the 12-hour open verification / surveillance for RC V23 and RC-V87 is overly restrictive and inconsistent with the open verification surveillance requirement - for - the - PORV isolation valves.

The current 31 day open verification surveillance for RC V22 and RC V88 is proposed to be changed to a-72 hour surveillance which is more conservative than the 31 day open verification and consistent with the open verification surveillance requirement for the PORY isolation valves.

2, The proposed change in the surveillance frequencies for verifying that the RHR suction isolation valves RC V22, RC V23, RC V87 and RC-V88 are open and

-eliminating the requirement to verify that power is removed from the motor operators for RC V88 and RC-V22 does not create the possibility of a new or different kind of accident frem any accident previously evaluated.

The proposed change in the open verification surveillance frequency and the elimination of the requirement to verify the removal of power from the motor operators ' does not create a new or different kind of accident because the disabling of the RHR ACI circuitry eliminates the mechanism for autoclosure of the: RHR suction isolation valves and concomitant loss of RHR cooling.

3.

The proposed change in the surveillance frequency for verifying that the suction isolation valves RC V22, RC V23, RC V87 and RC V88 are open and eliminating the requirement to verify that power is removed from the motor operators for RC V88 and RC V22 does not involve a significant reduction in a margin of safety. The elimination of the requirement to verify that power is removed from the motor operators for RC-V88 and RC V22 provides an increase in the margin of safety because these isolation valves along with RC-VS7 and RC-V23 will have power available allowing their-expeditious closure from the control room in the event of a RilR system LOCA. The disabling of the RHR ACI circuitry eliminates the mechanism for autoclosure of these valves and concomitant loss of RHR cooling.

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WESTINGHOUSE PROPRIETARY CLASS 3 5

F G

3 S.2 Proposed Revision of Technical Specifications b

f.

This section provides the technical spe:ification revisions necessary to t,

b implement the removal of tne RHES autoclosure interlock feature at each of the g-e four reference plants, y

SALEM f

The portion of the '.S month surveillance contained in specificati:n 4.5.2.i t

associated with verifying that the RHRS su: tion / isolation valves automatically close on a RCS pressure signal should be deleted as shown in Figure B-S.

With i

the removal of the auto:losure interlo:k function, there is no longer a need to retain this surveillance requirement.

It should be noted that the RHRS open permissive interlock surveillance re;uirement remains unchanged.

CALLAWAY The portion of the 18 month surveillance c:ntained in specification 4.5.2.d.1.b associated with verifying that the RHES suction / isolation valves automatically close on a RCS pressure signal should be deleted as shown in i

Figure B-9.

With the removal of the autoclosure interlock function there is no longer a neod to retain this surveillance repuirement.

It should be noted that the RHRS open permissive interlock surveillance requirement remains unchanged.

The 31 day surveillance contained in Specifications 4.4.9.3.2.a.1 and 4.4.9.3.2.b.1, verifying that the RHRS suction / isolation valve is open with power removed to the valve operator, should be deleted as shown in Figure 6-10.

With the rem; val of the autoclosure interlock circuitry on the RHRS suction / isolation valve a failure of a pressure transmitter can not result in the valves stroking closed.

Thus the postulated occurance of a singio failure isolating both RHRS trains while the RHRS relief valves are providing cold overpressure protection can not occur and the surveillance requirement to open and lock-out power to the valves is redundant.

00330 lo/0211 P,8 s-4

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WESTINGHOUSE PROPRIETARY CLASS 3 p

i The RHRS suction / isolation valves which had been in the 31 day surveillance

+

I h

should be ad.ed to the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> surveillance which requires the valve to be 4

4 verified open as snown in Figure 8-10.

This is necessary to insure that free i 0 communication exists between the RCS and the RHRS when the RHRS relief valves are providing t id overpressure protection to the RCS, li Additionally, the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> surveillance interval of specification 4.4.9.3.2.a.2 j

and 4.4.9.3.2.b.2 should be changed to be consistent with the surveillance i

interval of specification 4.4.9.3.1.c for verifying that the PORV isolation valves are open when the PORV is used for overpressure protection.

The change is shown in Figure 8-10.

Bases section 3/4.4.9 should be modified to delete the discussion on removing i

p. er to the RHRS suction / isolation valves as shown in Figure 8-11.

ll o

1:

.c Go NORTH ANNA UNIT 1 7

t 1

6 The 18 month surveillance contained in Specification 4.7.9.1.a associated with verifying that the RHRS suction / isolation valves automatically close on a RCS pressure signal should be deleted as shown in Figure B-12. With the removal u

ji of the autoclosure interlock function, there is no longer a need to retain 4 :

[

this surveillance requirement.

I SHEARON HARRIS j --

The portion of the 18 month surveillance contained in specification 4.5.2.d.1 associated with verifying that the RHRS suction / isolation valves automatically close on a RCS pressure signal should be deleted as shown in Figure 8-13.

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With the removal of the autoclosure interlock function there is no longer a l

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need to retain this surveillance requirement, it should be noted that the 4-RHRS open permissive interlock surveillance requirement remains unchanged.

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00330:10/021188 lI 8-5 o

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WESTINGHOUSE PROPRIETARY CLASS 3 R YlSION liq [eOfmCV CDef C00Ll 4 tTS"'

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_,.f e -.,.

I 4.b.! thCh [CC$ sesystes shall be Gewonstrated OPitA&LL:

At least once per 12 howes by verifying that the following valves a.

i are in the inctceted positions with power to the valve operators

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removes:

e tit 90m j

valve kJubet p1ve functien

%elve c

Bar-NY-8813 Safety Injection to Open ter5T 16 elation W1, De W-S$C2A( B) 11 puse Cischerpe Closed j

Ho'. Leg Ise Vivs

]

EM W-8835 Safety injedian Open 1

Cold Leg !se valve j

(J-efy* B&a0 RMt/$1 hot Leg Closed tecirc Iso Valve (J-Hv* t809 A PMW to Accum Inj Open Loops 1 & 2 1so V1v LJ HV 6 soft RMt to Accum Inj Open Locos 3 & 4 Iso v1v t.

At least arate per 31 says by:

I

1) verifying that the ICC$ piping is full of water by venting the (CC1 pump casings and eccessible sischarge piping h10m points, anc verif ing that each valve (manual, power-operated, of tutamatic) 2)

y in the 110w path that is not locsad, saaled, or otherwise g

secured in position, is in its correct position.

c.

By a viewal inspectlen which verifies that no loose escris (tegs, trash, clothing, etc.) is present in the contairment weich cowie be transported to the containment sumo and cause restriction of the puso suctises during LOCA conditians. This visal inspection shall be performed:

1) For all accessible areas,of the containment prior to estan11 thing CDWTAlmLNT INTIGR1,1Y and

2) Cf the areas af fected within contalrument at the completion of each contatraent entry when CONTA1*ENT INTEGt!TY is estan11shed.

At least once per 18 months by:

1) verif ying estomatic ta@th interlock action of the RMt systae free the Ranctor Coolant Systas by ensuring thatA

/ @th a simulated or actual teactor Coelant Systes pressure sigaal geester than er equal to 425 psig the intarlocks prevent the valves f ree being opened, and

/ ltith f simul d se ual actor lent ysJs4 p wM1:

v' V siip41 les han o egal 75c ig i instrl cycse valve

.o oW tic. y cle CAttaway - unti 1 3/4 5 4 I

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I 1

Figure 8-9.

Proposed Callaway Surveillance Requirement 4.5.2.d.1 4

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0872r1D/012788 8-15 t

I WESTINGHOUSE PROPRIETARY CLASS 3 a

i q

' REVISlott _ 2 efactesextantsysta m

he

$U8vt!LLsNCf R10V1tfufMTS i

i 4.4.9,3.1 tech PORV shall be demonstrated CPERA8LI by.

e.

Performance of an ANALOG CMAMN!L OPfRATIO%AL TEST on the PCry

- actuation channel, but escluding velve soetation, within 31 says prior to entering a condition in welch the PCAV is reewired CPERMLE i'

and at least once per 31 says thersafter when the PCry is requireg OPLAASLE; 4-.

(f

-b.

Performance of a CMANNEL CAllltATION en the PCRV actuatten channel at at least once per 18 months; and f

c.

Verifying the Potv isolation valve is open et least once W e 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> when the PCRV is being used for overprsssure protection.

4.4.9.3.2

[ech RHR suction relief valve shall be demonstratec CPERMLE when the RMA suction reitef valves art being used for cold overpressure protection as follows:

a.

For RMt sv: tion relief valve 87068-Jf By v ifyin et les once r 31 thatJMI RCS,bditipra is atto alve 51V) sia i pen wit (power go t #

/

py ve erster emoved and p ty verif ing at least once per M' hours that IR$!YY7028 i

/

hr, V4h(.f b.

For RNA suction relief valve 8704A:

Iy verifying at least once'per)/ hours that IR$1Y 8701A grd [fCM b

$d' open.

n) are.

W VAbel c.

Testing pursuant to specification 4.0.5.

4.4.9.1.3 The 4 5 vent (s) shall be verified to be open at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />" een the vent (s) to being used for overpressure protection.

• ! cept when the vent pathway is provided with a velve weich is locked, sealed, or otherwise secured in the open position, then verify these valves open at least once per 31 days.

CALLAmay

• UN!T 1 3/e 1-35 l

i i

i-Figure 8-10.

Proposed Callaway Surveillance Requirement 4.4.9.3.2 s

0872v:10/012788 8-16 d

1_

WES11NGHOUSE PROPRIETARY CLASS 3 Ii-ISIOM.1

.f as Coo-nm.

.t_*5f 5 y

seraTut(Caettaued) tw -e of tu c

p. site evn. ta s.cessary t. ut c es.natin %.t.

u.itations nec.vae it 1. possme f.e ceneisi.ns ta utst such tut.ver tne j

course of tr.3 heata, re the contre 111.g e.nditten evitches free tw insta i

La the evtstee and the pressure 11eit must at all times t>e based on analysis i

of the aest critical critarten.

Fthally. De tempetita cveves for the host. rata esta aM the cooloown este 6ata are adjusted for peastble errors in the pressure and temperature sensing instruments by the values tedicated on the respective curves.

Alpough the pressuriser operates in temperature ranges above those for wnich there is reason for concern of nonouctile failure, operating 11eits are prevloed to assure compattttlity of operation with the fe'tigue analysts perfereed in accoccance with the A&ME Cooe requirements.

TM CettAAlt!TY of tus PorYs. ee two PNI suctlen relief valves, or an t:5 vent opening of at least 2 square inches ensures that tM RCS will be protected from pressure.ransients weitch could anceed the Itaita of Apoendia C to 10 CFR Port 50 wnen one se son of the RCS cold legs are less than er eq.a1 to 368'F.

~

tither P0ry or either EMR suction relief valve has 60 equate relieving casa 11*

tty to protect the 203 from everpeessucitation unen the transient is limited

[

t. eiwen m the start.f an me RCP iu we secon=> -eter t.moeratues of the steen generator less than or equal to 50*F noove the 20$ cold leg teeoerstures, or (2) the start of a centrifugal charging puso and its injection into a mater-seitd tts.

EMR RC3 sucyton tse tion vfives 873A arut are ir,terlocsyd vi n " A*/'

train a ce ra pressu tranpitter op valv 87C2aA nd B int octe with

'8" tr n utos ange p saurs t nsmit r.

Regewing ef va es

$701 and 87.A. pre att a ingle f lure f inedf'e rtent 1:01 ting th RNA actio relieffalves 11e met ining t 1seVattee 404811 ty fo both flow ths.

In enditten tu opening RC$ vents ta meet the requirement of Specifica-Llan 3.a.9.3c.. It is 'acceptante to remove a pressuriser Cees safety valve.

upen a POW hiock valve and remove power from the valve operator in conjunction with disanneenly of a Potv and removal of its internals, or otherwise open the ECS.

)

C0to Ovtepef35Uef The maatsum Allowed PORY 5etpoint for the Cald Overgmssun mitigation system (CDM5) is serived by analysts watch sooels the perfemance of the C>s asswaine earteus mass tout and heat treet transients. Operation with a Pctv seteelet less than er equal ta tM mastnum setectnt ensures tut Acceadia G cetteria will ret t>e violated with constocration for 1) a easieum pressure l ;I eversheet beyone the perv seteetnt unten can occur as a result of time celays 1

In signal processing and valve opening; 2) a 50*F heat transport effect mace i

cat tAmay - un!T 1 3 3/4 a-15 Figure 8-11.

Proposed Callaway Bases Section 3/4.4.9 1

l 1

0872v:1er 8-17 i

i E -

4 8

New 1lampshire Yankee -

May 16,1991 ENCLOSURE 4 TO NYN-91079 SUPPLEMENTAL INFORM ATION AND NO SIGNIFICANT HAZARDS CONSIDER ATION FOR PROPOSED CHANGES TO TECHNICAL SPECIFICATION 3.4.9.3 (RHR SUCTION RELIEF VALVE c.ETPOINT CH ANGE)

L

.. ~.,

NH Y's

• Request for License Amendment: Residual Heat Removal System Isolation Valve Autoclosure Interlock Removal" also proposed a change to the RHR suction relief salve l

setpoint upper limit.

Currently Technical Specification 3.4.9.3 states that the RilR suction relief valves have a setpoint of 450 psig ;t 3%

The proposed change maintains the nominal relief valve setpoint of 450 psig but reduces the RilR suction relief valve setpoint upper limit to 450 psig + 0, - 3 E The effect of this proposed change is to reduce the maximum acceptable valve setpoint by 13.5 psig from 463.5 psig to 450.0 psig, This change in the RHR suction relief valve setpoint upper limit is proposed to conservatively ensure adequate overpressure protection for the RilR System as dictated by a re-analysis of the RilR suction relief valve capacity. The RllR suction relief valve capacity was re-analy/ed, as was done by Westinghouse for the four referenced plants, and documented in WCAP-11736 " Residual Heat Removal System Autoclosure Interlock Removal Report" (Section 9 0).

A summary of the Seabrook Station RHR relief vahe capacity re-analysis is provided below which supports the RHR suction relief vahe setpoint change. This re-analysis was performed by Yankee Atomic Electric Company (YAEC) for NilY.

as SBC-383 entitled *RilRS Overpressure Protection", dated JuneThe YAEC calculation is identified 26, 1990.

RHR REllEP VAINE CAPACITY - SEABROOK STATION The Seabrook Residual Heat Removal System (RilRS) is protected from inadvertent overpressurization by various code relief vahes located throughout the system. Of these, primary protection is provided by individual suction line relief vahes, located in each subsystem's RHRS pump suction line from the associated Reactor Coolant System (RCS) hot leg.

The main purpose of the RHRS relief vahes is to protect the RHRS from overpressurization during residual heat removal operation, and protect the RCS from overpressuri7ation when the valves are qualified as OPERABLE in Technical Specification 3.4.9.3.a.

The design basis overpressurization events for both the RCS and the RHRS include:

L inadvertent RCS mass addition by operation of one Centrifugal Charging Pump (CCP); or 2.

Inadvertent RCS mass addition by operation of one Safety injection Pump (SIP); or 3.

Inadvertent RCS heat addition by operation of one Reactor Coolant Pump (RCP), with steam generators 50 F hotter than RCS temperature.

Events more limiting than these are precluded by Technical Specifications.

basis event is assumed to occur while the RCS is water solid and without Each design address the fact that operation with only one RHRS train open to the RCS is permitted, only letdown. To one RHRS relief valve is credited for RHRS overpressure protection.

since technical specifications require both relief valves OPERABLE whenThis is conservathe, used for RCS overpressure protection.

The RHRS relief valves have oversized disk assemblies and balanced bellows, allowing full lift essentially at the opening pressure.

Each RHRS relief vahe is rated for 900 gpm at the 450 psig opening setpoint, relieving 400 F water against a backpressure of 3 psig constant plus 50 psig buildup due to flow resistance in the discharge piping.

piped to the Pressurizer Relief Tank (PRT) which is normally operated with a nitrogen coverT pressure of 3 psig.

having a release pressure of 86 to 100 psig.The PRT is protected from ove: pressurizat disks 1

Inadvertent mass addition from the operation of either one CCP or one SIP could occur over At the full range of allowable RHRS operation from ambient to 350 F RCS temperature.

the 450 psig RHRS relief valve setpoint, one CCP or one SIP has a capacity of 425 ; 3m or It was verified by calculation that one RHRS relief valve can pass 565 gpm respectively.

the 450 psig setpoint for fluid temperatures up to 350 F.

This more than 635 gpm at k

includes an allowance for discharge piping flow resistance and an maximum PRT bac pressure The maximum pressure for these mass addition transients is limited to the This is less than the limit of 100 psig.

opening setpoint of 450 psig at the RilRS relief valve location.for low temp required by Technical Specifications, it was verified by calculation that a relief rate of 581 gpm will accommodate the inadvertent heat addition trtnsient for RCS temperatures up to 250 F.

Steps in several plant operati,ng than 200 F.

of an RCP when the RCS is solid and greater the start procedures preventFrom above, one RHRS relief valve can pass more than 635 gpm at the 450 psig The maximum pressure f a this heat addition transient for fluid temperatures up to 350 F.

This is less is limited to the opening setpoint of 450 psig at the RilRS relief valve location.

f than the limit for low temperature RCS overpressure protection required by Appendix G o 10 CFR 50 as required by Technical Specifications.

The maximum pressure for all the design basis overpressure transients is limited to 450 psig However the possibility of an operating RHRS pump and at the RHRS relief valve location.

ll the lower elevation of RHRS pump suction and discharge piping in the equipment vault wi produce local fluid pressure above the 450 psig relief valve setpoint.

The design overpressure limit of the RHRS is 660 psig (110% of design pressere as required by the It was verified by calculation that the maximum RHRS ASME Code Section NC 7311).

pressures are less than 660 psig in the pump suction and discharge piping.

In summary, each RHRS relief valve arad discharge system has sufficient capacity to provide RHRS and RCS overpressure protection against the specified design basis events when the opening setpoint is,<L450 psig.

NHY has determined that the proposed RHR suction relief valve setpoint upper limit change does not introduce a significant hazard consideration pursuant to the requirements of The basis for this determination is provided below:

10CFR50.92.

The proposed change in the RHR suction relief valve setpoint upper limit does increase in the probability or consequences of an 1.

not involve a significant The relief valve setpoint change has no effect accident previously evaluated.

on the probability of occurrence of a Reactor Coolant System (RCS) mass or addition transient which may require the RHR suction relief valves to heat protect the RHR system and the RCS from overpressurization, The consequences of a RCS mass or heat addition transient are not increased, as the relief valve setpoint change is intended to conservatively ensure that The proposed change in the adequate overpressure protection is provided.

RHR suction relief valve setpoint is primarily attributable to the reanalysis of the RHR suction relief valve capacity by Atomic Yankee Electric Company in dated J une 26, 1990.

calculation SBC-383, "RHRS Overpressure Protection" NHY reviewed actual RHR suction relief valve setpoints determined during The actual RHR suction relief valve setpoints were below 450 psig, testing.

thus RHR overpressurization would have been precluded in a mass or heat addition transient.

2

~ - _ _ _

~""*"'-+%-_

. ~..

e 2.

The proposed chang.: in the RilR suction relief valve upper limit w!!! not.

create the possibility of a new or different kind of accident from any previously evaluated, The RHR suction relief ' valve function is to protect the RilR system from overpressurization during a RCS mass or heat addition transient.

Additionally, the RHR suction relief valves may be utilized to provide RCS

cold overpressure protection as provided by Technical Specification 3.4.9.3..

The change in RHR suction relief valve setpoint upper limit will ensure that this overpressure-protection function is provided. No change to the RHR suction relief valve lower limit setpoint-has been proposed, therefore the probability of an inadvertent opening of the RiiR suction relief valves is not ir, creased. No new or different types or accidents will be created by the RHR suction relief valve setpoint upper limit change, 3.

The proposed change in the RHR suction relief valve setpoint upper limit will not significantly reduce the margin of safety associated with the overpressure protection function of these valves. The proposed revised relief setpoint will maintain the margin of safety associated with the RilR su'ction relief valve overpressure protection function by assuring that the maxim.im opening setpoint does not exceed the maximum opening setpoint which.has been conservatively analyzed. The actual RHR suction relief valve setpoint is verified as part of NHY laservice Test Program requirements for these valves, 3

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