ML20195G033

Proposed Tech Specs Pages,Revising TS 3.7.1.6 & Bases by Modifying LCO to Require Four ARVs to Be Operable, Eliminating Use of Required in Action Statements & Adding New Action for Three or More ARVs Inoperable

ML20195G033
Person / Time
Site:	Wolf Creek
Issue date:	06/11/1999
From:	WOLF CREEK NUCLEAR OPERATING CORP.
To:
Shared Package
ML20195G025	List: ML20195G021 ML20195G033
References
NUDOCS 9906150196
Download: ML20195G033 (14)

Text

_ _ _

^

Attachment.IV to ET- 99-0006 Page 1.of 5 9 a ATTACHMENT IV PROPOSED TECHNICAL SPECIFICATION CHANGES CURRENT TECHNICAL' SPECIFICATIONS

~

9906150196 990611 PDR ADOCK 05000482 P

- PDR _ _ _

A

Atte.chment IV to ET 99-0006 S Page 2 of 5 -

PLANT SYSTEMS STEAM GENERATOR ATMOSPHERIC RELIEF VALVES LIMITING CONDITION FOR OPERATION 3.7.1.6 At least -

steam generator atmospheric relief valves (ARV's) shall be OPERABLE.

APPLICABILITY: MODES 1, 2, and 3.

ACTION:

a.

With one of the@@dVed) ARV's inoperable due to causes other than excessive seat leanage, within 7 days restore the ARV to OPERABLE status, or be in HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN

• within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. d q

M n ne t re ir A s no r o h e es ve at e u to c s

- ^ ~ ak e, it n r re o e o h e red RV' to PE rQ *'T^ n e ryext our an in T L st us r U' 0 wi in w ou _

With one or more VA1VVottfr5i)ARV's inoperable because of excessive seat leakage, close the associated block valve (s) within I hour and restore the ARV to OPERABLE within 30 days, or be in HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.} }

j h h provisions of Specification 3.0.4 are not applicab1 D '- I SURVEILLANCE REQUIREMENTS 4.7.1.6 tion 4.0.5. No additional requirements other than those required by Specifica-WOLF CREEK - UNIT 1 3/4 7-9a Amendment No.30

i' Attachment IV to ET 99-0006 Page 3 of 5 l

l I e l

l CURRENT TECHNICAL SPECIFICATION (CTS) INSERTS l

INSERT A

b. With two ARV's inoperable due to causes other than excessive seat leakage, restore all but one ARV to OPERABLE status within 72 l

hours or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in l HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

c. With three or more ARV's inoperable due to causes other than excessive seat leakage, restore all but two ARV's to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

I i

l I

I i

l l

.. Attachment IV to ET 99-0006

j. Page 4 of 5 i l

a 9

PLANT SYSTEMS

- RASES a

3/4.7.1.5 MAIN STEAM LINE ISOLATION VALVES a

a The OPERABILITY of the main steam line isolation valves ensures that no more than one steam generator will blowdown in the event of a steam line rupture. This restriction is required to: (1) minimize the positive f', reactivity effects of the Reactor Coolant System cooldown associated with the blowdown, and (2) limit the pressure rise within containment in the event the  !

steam line rupture occurs within containment. The OPERABILITY of the main steam isolation valves within the closure times of the Surveillance Requirements are consistent with the assumptions used in the safety analyses.

3.4.7.1.6 AnC+bf R45 cacddoum to RMd STEAM GENERATOR ATMDSPHERIC RELIEF VALVESI cwlihon* feit.dn3 soewerfill can be cenpletut A > tAsig manner.

The operability of the main steamline atmos eric relief valves (ARV's) ensures that reactor decay heat can be dissipat to the atmosphere in the event of a steam generator tube rupture and los of offsite power and that the Reactor Coolant System can be cooled down for sidual Heat Removal System operation. The number of utbet33ARV's assure s that the subcooling can be achieved,consistentwith@sneassumptionsusedinthesteamgeneratortube Mbed.='

rupture analysis, to facilitate equalizing pro ssures between the Reactor JCoant System anti theta @MjR) steam generatorM/ F 1)hg he 1 t o Tni ti c it'4ns /on' one RV sr ui d. In hit c e wi r s per e f s il all o A o ur a a t r V s s o ass iat w< t f t ste ne t , e V in all le or r uir Nt r _v . _ _

lusEKT e>

vesca.t 1 Each ARV is ecuipped with a manual block valve (in the auxiliary follag0 )( buildine)

- to provice leakaget Closure of thea block positive valvesshutoff capability of all ARV's should because an ARV seat of excessive develop f*""S / leakage does not endanger the reactor core; consistent with plant accident and transient analyses, decay heat can be dissipated with the main steamline safety valves or a block valve can be opened manually in the auxiliary building and the_ ARV can be used to control release of steam to the asteosphere. the eam nera r tu uptu vent riaaryAo seco ary, j De ge n te ated y de ssur t $ acto oolaptdyst tV i e ss zer r rat relie ve f 3/4.7.1.7 MAIN FEEDWATER ISOLATION VALVES The OPERABILITY of the main feedwater isolation valves: (1) provides a pressure soundary to permit' auxiliary feedwater addition in the event of a -

main steam er feedwater line break; (2) limits the RCS cooldown and mass and energy releases for secondary line breaks inside containment; and (3) mitigates steam generator overfill events such as a feedwater malfunction, with protection provided by feedwater isolation via the steam generator high-high level' trip signal. The OPERABILITY of the main feedwater isolation v valves within the closure times of the surveillance requirements is consistent with the assumptions used in the safety analysis.

3/4.7.2 DELETED WOLF CREEK - UNIT 1 B 3/4 7-3 Amendment No. 40,89 1

fut m

y Attachment IV to ET 99-0006

'Page-5.of 5 i

e .

INSERT B

-In the' event of'a SGTR, at least two intact steam generator ARV's are required 4 for.RCS.cooldown. In this case, with four ARV's OPERABLE, if the single J failure.of one ARV occurs-and another ARV is assumed to be associated with the ruptured steam generator, two intact steam generator ARV's remain available for' required RCS cooldown.

I i

I l

l l ~

Attachment V to ET 99-0006 I Page 1 of 8 l

1 i

l l

l ATTACHMENT V l PROPOSED TECHNICAL SPECIFICATION CHANGES IMPROVED TECHNICAL SPECIFICATIONS 1

l l

1 \

E At.tachment'V to ET 99-0006-Page 2'" 8 ARVs 3.7.4 )

l 3.7 PLANT SYSTEMS 3.7.4 Atmospheric Relief Valves (ARVs)

Few LCO 3.7.4 ARV lines shall be OPERABLE.

APPLICABILITY: MODES 1,2, and 3.

i ACTIONS -

CONDITION REQUIRED ACTION COMPLETIONTIME l

A. OneCetfuir6d RV line A.1 NOTE inoperable. LCO 3.0.4 is not 9 ,,, applicable.

I thm ene.essive. les e.

Restore required ARV line 7 days to OPERABLE status.

B. Two W M RV B.1 Restore all but one required ARV line to ours

_ lines inoperabig.

4 c . s s o m m ,- OPERABLE status.

Han eu:ess'v naakge kssn;T s!!-

E 4.

l Required Action and A.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time not met. AND A.2 Be in MODE 4. 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> j

)

Wolf Creek- Unit 1 3.7-9 Amendment No.123 t ]

Atf.achment V to ET 99-0006 Page 3 of 8 I

INSERT 3.7-9 l

l C. Three or more ARV lines C.1 Restore all but two ARV 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> inoperable for reasons lines to OPERABLE status.

other than excessive seat leakage l

D. With one or more of the - - - -

--NOTE -

ARVs inoperable because LCO 3.0.4 is not applicable, of excessive seat leakage. - --

D.1 Initiate action to close the immediately associated block valve (s).

AND D.2 Restore ARV(s) to 30 days OPERABLE status.

l l

l 1

I l

L

Attachment V to ET 99-0006 Page 4 of 8- ARVs B 3.7.4 B 3.7 PLANT SYSTEMS B 3.7.4 Atmospheric Relief Valves (ARVs)

BASES BACKGROUND The ARVs, or the Steam Dump System to the condenser, provide a method for cooling the unit to residual heat removal (RHR) entry conditions, as discussed in the USAR, Section 10.3 (Ref 1). Further cooldown in conjunction with the RHR System is also possible. This is done in conjunction with the Auxiliary Feedwater System providing cooling water from the condensate storage tank (CST). The ARVs also provide Mg the mear*.s to equalize pressure between the Reactor Coolant System and thelfa9thiiQsteam generator following a postulated steam generator tube rupture event. The ARVs may also be required to meet the design cooldown rate during a normal cooldown when steam pressure drops too low for maintenance of a vacuum in the condenser to permit use of the Steam Dump System.

One ARV line for each of the four steam generators is provided. Each ARV line consists of one ARV and an associated manual block valve.

, The ARVs are provided with upstream block valves to permit their being tested at power, and to provide an attemate means of isolation. The ARVs are equipped with pneumatic controllers to permit control of the cooldown rate.  !

i The ARVs are provided with a pressurized gas supply of nitrogen that, on a loss of pressure in the normal instrument air supply, automatically i supplies nitrogen to operate the ARVs. One accumulator supplies one ARV and one auxiliary feedwater control valve per steam generator. The nitrogen accumulator supply is sized to provide sufficient pressurized gas '

to operate the ARVs for the time required for Reactor Coolant System cooldown to RHR entry condition.

A description of the ARVs is found in Reference 1.

APPLICABLE The design basis of the ARVs is established by the capability to cool the SAFETY ANALYSES unit to RHR entry conditions. The design safe shutdown requires two steam generators, each with one ARV. The unit can be cooled to RHR entry conditions with only one steam generator and one ARV, utilizing the cooling water supply available in the CST. The valves will pass sufficient flow at all pressures to achieve a 50 F per hour plant cooldown rate. The total capacity of the four valves is 15% of rated main steam flow at steam generator no-load pressure.

Wolf Creek - Unit 1 B 3.7.4-1 Revision 0

At.tachment V.to ET 99-00 ,

Page 5 of 8 g gj.,gg  % g Rc.s costa. tan +o saHR n% canettan6 B 3.7.4

}

u,sA,9 intact scs Any's ' A n.c 3 .<3 +o I Qwmiwa.tm. Pe*a.r3 b seconde breAftea.j APPLICABLE - In the accident analysis presented in Reference 2, the ARVs are assumed SAFETY ANALYSES to be used by the operator to cool down the unit to RHR entry conditions (continued) - for accidents accompanied by a loss of offsite power. The main steam

. safety valves (MSSVs) are assumed to operate automatically to relieve l:

gg/ steam and maintain the steam generator pressure below the_desian value.

For the recovery from a steam generator tube rupture (SGTR) eventithe N operator !=- .equired to perform aMcooldowgto establish G n3No ihtactq( adequate subcooling as a necessary step to terminate the crima_rv to hm gener.evcsJ secondary break flow into the ruptured steam generator.6he time k required to terminate the primary to secondary break flow for an SGTR is more critical than the time required to cool down to RHR conditions for this event and also for other accidents. Thus, the SGTR is the limiting event for the ARVs. The number of ARVs required to be OPERABLE to satisfy I Og# the SGTR accident analysis requirements ish lf a single failure of l eg one occurs and another is associated with the@SG, R would remain OPERABLE for heat remova as discussed in R ce 3.

h itdScInehARVs

are equipped with block valves in the event an ARV spuriously l

fails open or fails to close during use.

The ARVs satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO~ ARV lines are required to be OPERABLE. One ARV line is reouired from each of@ steam generators to ensure that at leasttiaer%W$line, 3available to conduct @cooldown following an SGTR, in which one steam generator becomes unavailabig, accompanied by a single, active j etua.b a steam failure of a second ARV line on an unaffected steam generator. _The block  :

8.P"cr**"*'^>* valves must be OPERABLE to isolate a failed open ARV line.fA c sed T P" ___ __

/bl val doesnot r er' r it RV ock lv is s pe bl e

u t a s

e cie r ra' tim oo t lysis or e pie . bl val th is s o 01 e ss' e l

(ARV at le age s ren t AR in n r e.

Failure to meet the LCO can result in the inability to achieve subcooling, consistent with the assumptions used in the steam generator tube rupture i (mpituwd1 analysis, to facilitate equalizing pressures between the Reactor Coolant _

. System _and theMsteam generator.fFanure % vneet me n.CO con als]o l (TApas.it me. rs< ,er3 capability fattosa'ing a. ser overfut scenario. _/  !

t

( An ARV is considered OPERABLE when it is capable of providing controlled relief of the main steam flow and capable of fully opening and closing on demandy _

_~

d. rut A i seat IsakASc., Emessive seat leage,

.e%+ hough nal' pe.rtelncing excessassoc iateA.eusiA a.syec'ific. o.ccep

. (cond'itions dictate, clemer, of the block. v4vv. +o itW+ leakage.

. Wolf Creek - Unit 1 - B 3.7.4-2 Revision 0

i Attachment V to ET 99-0006 Page 6 of 8 ARVs B 3.7.4 BASES.

LCO The nitrogen accumulator tanks supplying the turbine driven AFW pump (continued) control valves and the steam generator atmospheric relief valves ensure an eight hour supply for the pump and valves.

APPLICABILITY In MODES 1,2, and 3, the ARV lines are required to be OPERABLE.

In MODE 4, the pressure and temperature limitations are such that the  !

probability of a SGTR event requiring ARV operation is low. In addition, the RHR System is available to provide the decay heat removal function in MODE 4. Therefore, the AR are not required to be OPERABLE in MODE 4. i,go l

In MODE 5 or 6, an SGTR is not a credible event.

for reason the APM ACTIONS A 1,

_ Ccu_em've ani.e leakage. %n tide

~

With one6tiid'r36dRV line inoperabl action must be taken to restore OPERABLE status within 7 days. The 7 day Completion Time allows for the redundant capability afforded by the remaining OPERABLE ARV lines, a nonsafety grade backup in the Turbine Bypass System, and MSSVs.

Required Action A.1 is modified by a Note indicating that LCO 3.0.4 does not apply.

kk"a 3.54- AD OC2_: 1 C**4i:w reasons.

niv* Ic2 KdSe __ aHw With@ or moreMARV laes inoperabl[ action must be taken to Og restore all buth ARV lines to CPERABLE status. Since the block valve can be closed to isolate an ARV, some repairs may be possible with the unit at power. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Completion Time is reasonable to repair inoperable ARV lines, based on the availability of the Turbine Bypass System and MSSVs, and the low probability of an event occurring during this period that would require the ARV lines.

hmeerssa.4..aQ 1andh (E

if the ARV lines cannot be restored to OPERABLE status within the associated Completion Time, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and in MODE 4 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The allowed Completion Times are reasonable, based on operating Wolf Creek - Unit 1 B 3.7.4-3 Revision 0

At'tachment V to ET 99-0006 Page 7 of 8 INSERT B 3.7.4-3a B.1 With two ARV lines inoperable for reasons other than excessive ARV seat leakage, action must be taken to restore all but one ARV line to OPERABLE status. Since the block valve can be closed to isolate an ARV, some repairs may be possible with the unit at power. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time is reasonable to repair inoperable ARV lines, based on the availability of the Steam Dump System and/or MSSVs, and the low probability of an event occurring during the restoration period that would require the ARV lines.

INSERT B 3.7.4-3b D.1 and D.2 Requiring a 30 day limit for restoring an ARV valve to OPERABLE status from inoperable, due to excessive seat leakage from the valve, provides assurance that the required number of ARVs will be available for plant cooldown. This action limits the period in which a block valve is closed due to excessive seat leakage of the ARV and minimizes the delay associated with manually opening a closed manual isolation valve (due to excessive seat leakage of the

/iRV) . Required Actions D.1 and D.2 are modified by a Note indicating that LCO 3.0.4 does not apply.

l I

I L

T ,

Attachment V to ET 99-0006

., .Page 8 of 8 ARVs B 3.7.4 l

BASES, ,

ACTIONS C.1 and C.2 (continued) experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

i SURVEILLANCE SR 3.7.4.1 l

REQUIREMENTS To perform a controlled cooldown of the RCS, the ARVs must be able to be opened remotely and throttled through their full range. This SR ensures that the ARVs are tested through a full control cycle at least once l per fuel cycle. Performance of inservice testing satisfies this requirement, and use of an ARV during a unit cooldown may satisfy this requirement.

Operating experience has shown that these components usually pass the l

Surveillance when performed at the required Inservice Testing Program Frequency. The Frequency is acceptable from a reliability standpoint.

1 SR 3.7.4.2 l The function of the block valve is to isolate a failed open or leaking ARV.  !

Cycling the block valve both closed and open demonstrates its capability l to perform this function. Performance of inservice testing or use of the block valve during unit cooldown may satisfy this requirement. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 month Frequency. The Frequency is acceptable from a reliability standpoint.

l REFERENCES 1. USAR, Section 10.3.

2. USAR, Chapter 15.

3. USAR, Section 15.6.3.

l- _ . . - . . . . - . _ _ . - - .

Wolf Creek - Unit i B 3.7.4-4 Revision 0 l

L.

At'tachment VI to ET 99-0006 Page 1 of 1 LIST OF COM4ITMENTS The following table identifies those actions committed to by Wolf Creek Nuclear Operating Corporation (WCNOC) in this document. Any other statements in this submittal are provided for information purposes and are not considered to be commitments. Please direct questions regarding these commitments to Mr.

Michael J. Angus, Manager Licensing and Corrective Action at Wolf Creek Generating Station, (316) 364-8831, extension 4077.

Cote 4ITHENT Due Date/ Event This proposed revision to the WCGS Technical Sixty days Specifications will be fully implemented within 60 following NRC days of formal NRC approval, issuance of the requested amendment.