ML20069K819

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Proposed Tech Specs to Allow 36-inch Isolation Valve Leak Measurement Be Performed at Least Once Per 18 Months, Providing Valves Remain Closed During Period
ML20069K819
Person / Time
Site: Clinton Constellation icon.png
Issue date: 06/13/1994
From:
ILLINOIS POWER CO.
To:
Shared Package
ML20069K808 List:
References
NUDOCS 9406170035
Download: ML20069K819 (10)
v • d • e


Text

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98> TLV;bdd h COM/MuN y CM//. Attachment 3 A -

x to U-602272 C Page 1 of 2 CONTAINMENT BUILDING VENTILATION AND PURGE SYSTEMS l

LIMITING CONDITION FOR OPERATION 3.6.1.8 The primary containment building ventilation 36-inch supply (IVR001A, IVR0018) and 36-inch exhaust (1VQ004A, IVQ004B) isolation valves and the containment purge 32-inch supply (IVR006A, IVR0068) and 12-inch exhaust (1VR007A, 1VR0078) isolation valves shalT be OPERABLE, and

a. Primary containment building ventilation 36-inch supply and exhaust isolation valve (s) may be open for containment ventilation system operation
  • with such operation limited to <S00 hours # per year for reducing airborne activity and atmosphere coiitrol for personnel safety.
b. Primary containment building ventilation 36-inch supply and exhaust isolation valves shall be closed when the 12-inch containment purge isolation valve (s) are open. The 12-inch containment purge valves may be opened for reducing airborne activity and for atmospheric control to support containment access requirements to perform surveillances in accordance with these Technical Specifications.## When the 12-inch containment purge system is not required to support these access needs, the 12-inch valves shall be closed.

APPLICABILITY: OPERATIONAL CONDITIONS 1, 2, and 3.

ACTION:

a. With the containment building ventilation 36-inch supply and/or exhaust isolation valve (s) inoperable or open for more than 500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> per year for containment ventilation system operation, within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> close the open 36-inch isolation valve (s) or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTOOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
b. With containment purge 12-inch supply and/or exhaust isolation valve (s) in-operable, within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> close the inoperable valve (s) or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
  • Containment ventilation system operation shall be defined as any time 36-inch l supply and/or exhaust isolation valves are open except when opened for l inservice testing performed pursuant to Specification 4.0.5. )
  1. Applicable for the period from initial fuel load to 3 months after completion of the first refueling outage, otherwise a 250 hours0.00289 days <br />0.0694 hours <br />4.133598e-4 weeks <br />9.5125e-5 months <br /> per 365 days limit shall l I

be imposed.

    1. The 12-inch containment. purge valves may be maintained open when required to support multiple daily access to the conta-inment to perform required surveillances.

CLINTON - UNIl 1 3/4 6-17 9406170035 940613 "

PDR ADDCK 05000461 7 P PDR f

Attachment 3 )

to U-602272 Page 2 of 2 CONTAINMENT SYSTEMS l

CONTAINMENT BUILDING VENTILATION AND PURGE SYSTEMS LIMITING CONDITIONS FOR OPERATION (Continued) 3.6.1.8 ACTION (Continued)

c. With the containment purge supply and/or exhaust isolation valves with resilient material seals having a measured leakage rate exceeding the limit of Surveillance Requirement 4.6.1.8.3, restore the inoperable valves 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 SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

SURVEILLANCE REOUIREMENTS 4.6.1.8.1 The cumulative time that the 36-inch supply and exhaust containment ventilation isolation valves have been open during the past 365 days for containment ventilation system operation shall "be determined

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at least once per 7 days' s G O r-

/8 n1cnN1's Qtt/ w' & n 42 C i

4.6.1.8.2 Deleted ' open}n -Hw G%ec.inhd w

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4.6.1.8.3 At least once per .92 dayc each 36-inch supply and exhaust contain-ment ventilation isolation valve (with resilient material seals) shall be demonstrated OPERABLE by verifying that the measured rate is <0.01 La when pressurized to Pa.

4.6.1.8.4 Prior to opening the containment building ventilation system 36-inch supply and/or exhaust valve (s), verify that each containment purge 12-inch supply and exhaust isolation valve is closed.

4.6.1.8.5 Prior to opening the 12-inch valve (s), verify that the 36-inch con-tainment building ventilation supply exhaust isolation valves are closed. Once the requirement for reducing airborne activity and atmospheric control is com-pleted, the 12-inch valves shall be closed.

I i

CLINTON - UNIT 1 3/4 6-13 l

1

Attachment 4 to U-602272 CONTAlt! MENT SYSTEMS Page 1 of 2 BASES ,

1 3/4.6.1.8 CONTAINMENT BUILDING VENTILATION AND PURGE SYSTEMS

-The 36-inch containment purge supply and exhaust isolation valves have permanently installed blocking devices to restrict their opening .to 50* during plant OPERATIONAL CONDITIONS 1, 2, and 3, since these valves have not been demonstrated capable of closing from the full open position during an l accident. Maintaining these valves blocked during plant operations ensures that excessive quantities of radioactive materials will not be released via the containment purge system. To provide assurance that the 36-inch valves cannot be inadvertently fully opened, they are blocked in accordance with staff's recommendations accepted in SSER 5, paragraph 6.2.4.1.

The use of the containment purge lines is restricted to the 12-inch purge supply and exhaust isolation valves since, unlike the 36-inch valves, the 12-inch valves close during accident conditions and therefore the site boundary dose guidelines of 10 CFR Part 100 would not be exceeded in the event of an accident during purging operations. The design of the 12-inch purge supply and exhaust isolation valves meets the requirements of Branch Technical Position CSB 6-4, " Containment Purging During Normal Plant Operations."

The use of the 12-inch containment purge exhaust and supply lines shall be in accordance with the. "Clinton Power Station Report on Containment Purge Operational Data Gathering and Evaluation Program and Proposed Containment Purge Criteria" provided in Illinois Power (IP) letter U-601410, dated April 4, 1989. Section 6 of the report provides the criteria for governing operation of the containment building ventilation (36-inch) and the continuous purge (12-inch) systems. The criteria balance ALARA dose to the worker with protection of the health and safety of the public.

Since continuous operation of the 12-inch containment purge system has been shown to be required to support access to the containment to perform Technical Specification surveillances during normal conditions while in OPERATIONAL CONDITIONS 1, 2 and 3, continuous operation of the 12-inch system is allowed except while venting the drywell for p"ressure control or while operating the

^ 36-inch _ system. g '7 M n Ctc]cWincontaT5iEiit h'W6atinunus do f6tFR 50purge Appendh

'3 4eshn9 iisincFthe~36 maweerls, inch containment' ) building ventila tion system is limited to only OPERATIONAL CONDITIONS 4 and S. Intermittent use of the 36-inch system.during OPERATIONAL CONDITIONS 1, 2, and 3 is permitted only for the purpose of reducing airborne activity levels, or containment pressure, and atmosphere control (excluding temperature and humidity), and shall be limited to the time limits identified in S ecification Mc>c d ever / Of ith a DlDe leakage rate for 36-inch supply NYeakage and exhaustintegrity tests, isolation va lves will provide +ar indication of resilient material seal degradation and will allow he opportunity fo repair before gross leakage failures develop. The 0.60 a1 'ng limit should not >

ceed when the stwr^ ctcld, b d '

CLINTON - UNIT 1 3/4 6-3 ^

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I Attachment 4  !

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v Page 2 of 2 i CONTAlhMEllT SYSTEMS .

1 BASES 3/4.6.1.8 CONTAINMENT BUILDING VENTILATION AND PURGE SYSTEMS (Continued)  !

i leak rate determined by the leakage integrity tests of these valves is added to the previously determined total for all valves and penetrations subject to Type B and C tests.

The limitations placed on the use of the containment building ventilation system during OPERATIONAL CONDITIONS 1, 2, and 3 are appropriate to minimize the poten-tial release of radioactive gases to the environment following a LOCA during normal plant operation. The operation of the 36-inch system is consistent with the requirements of Branch Technical Position CSB 6-4, " Containment Purging During Normal Plant Operations."

3/4.6.2 DRWELL 3/4.6.2.1 DRYWELL INTEGRITY Drywell integrity ensures that the steam released for the full spectrum of dry-well pipe breaks is condensed inside the primary containment either by the sup-pression pool or by containment spray. By utilizing the suppression pool as a heat sink, energy released to the containment is minimized.and the severity of the transient is reduced.

l 3/4.6.2.2 DRYWELL BYPASS LEAKAGE The limitation on drywell bypass leakage rate ensures that the maximum leakage which could bypass the suppression pool during an accident would not result in the containment exceeding its design pressure of 15.0 psig. The integrated drywell leakage value is limited to 10% of the design drywell leakage rate.

The limiting case accident is a very small reactor coolant system break which will not automatically result in a reactor depressurization. The long term dif-ferential pressure created between the drywell and containment will result in a significant pressure buildup in the containment due to this bypass leakage.

3/4.6.2.3 DRYWELL AIR LOCKS The limitations on closure for the drywell air locks are required to meet the restrictions on DRYWELL INTEGRITY and the drywell leakage rate given in Speci-fications 3.6.2.1 and 3.6.2.2. The specification makes allowances for the fact that there may be long periods of c.ime when the air locks will be in a closed j and secured position during reactor operation. Only one closed door in each air lock is required to maintain the integrity of the drywell.

I CLINTON - UNIT 1 B 3/4 6-4

Attachment 5

- to U-602272 PCIVs Page 1 of 6 3.6.1.3 SURVEllLANCE REQUIREMENTS (continued)

I SURVEILLANCE FREQUENCY

- N OTE -- -

SR 3.6.1.3.5 ------------------NOTES------------------ gg 3, o, z /3 e/-  ;

1. Only required to be met in MODES 1, app /T M /e 2, and 3. 1 _ _ . _ _ _ _ . _ . _ _
    1. '6
2. Results shall be evaluated against f acceptance criteria of SR 3.6.1.1.1 wiO /OCFR So, in accordance with 10 CFR 50, Appencfig 7, as Appendix J, as modified by approved pgoc)[f;icj g exemptions. Y

.. .................................... Cr}? tomo Sternfh- -._

MS, Perform leakage rate testing for each !S' d::y:

primary containment purge valve with resilient seals. AND Once within 92 days after opening the l valve SR 3.6.1.3.6 Verify each automatic PCIV actuates to 18 months the isolation position on an actual or simulated isolation signal.

f (continued) r CLINTON 3.6-16 Amendment No. A

Attachment 5

'C to U-602272 I Page 2 of 6 PCIVs  !

O A e O[rt4/ckd i h Codd.hmtA/ Cd /- B 3.6.1.3

^-

1 BASES i ACTIONS 8.1 (continued) that meet this criterion are a closed and de-activated automatic valve, a closed manual valve, a blind flange,- and a check valve with flow through the valve secured. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is consistent with the ACTIONS of  ;

LC0 3.6.1.1.

C.1 With the secondary containment bypass leakage rate, hydrostatic leakage rate, or MSIV leakage rate not within limit, the assumptions of the safety analysis may not be met. Therefore, the leakage must be restored to within limit within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Restoration can be accomplished by ,

isolating the penetration that caused the limit to be exceeded by use of one closed and de-activated automatic valve, closed manual valve, or blind flange. When a penetration is isolated, the leakage rate for the isolation penetration is assumed to be the actual pathway leakage through the isolation device. If two isolation devices are ,

used to isolate the per etration, the leakage rate is assumed i to be the lesser actual pathway leakage of the two devices. i The 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Completion Time is reasonable considering the  ;

time required to restore the leakage by isolating the penetration and the relative importance of secondary ,

containment bypass leakage to the overall containment '

function.

0.1, 0.2, and 0.3 In the event cte or more containment purge valves are not ,

within the purge valve leakage limits, purge valve leakage '

must be restored to within limits or the affected penetration must be isolated. The method of isolation must be by the use of at least one isolation barrier that cannot be adversely affected by a single active failure. Isolation barriers that meet this criterion are a closed and l de-activated automatic valve, closed manual valve, and blind i flange. If a purge valve with resilierit seals is utilized to satisfy Required Action 0.1, it must have been l I

demonstrated to meet the leakage requirements of  ;

SR 3.6.1.3.5. The specified Completion -Time is reasonable, considering that one containment purge valve remains closed (continued) l CLINTON B 3.6-19 Revision No. A i i

I

Attachment 5-

' to U-602272 Page 3 of 6 PCIVs B 3.6.1.3 BASES ACTIONS 0.1. D.2. and 0.3 (continued)

(refer to the requirements of SR 3.6.1.3.1; if this requirement is not met, entry into Condition A and B, as appropriate, would also be required), so that a gross breach of containment does not exist.

In accordance with Required Action D.2, this penetration flow path must be verified to be isolated on a periodic basis. The periodic verification is necessary to ensure that containment penetrations required to be isolated following an accident, which are no longer capable of being automatically isolated, will be isolated should an event occur. This Required Action does not require any testing or valve manipulation. Rather, it involves verification that those isolation devices outside containment and potentially capable of being mispositioned are in the correct position.

For the isolation devices inside containment, the time period specified as " prior to entering MODE 2 or 3, from MODE 4 if not performed within the previous 92 days" is based on engineering judgment and is considered reasonable in view of administrative controls that will ensure that  :

isolation device misalignment is an unlikely possibility.

For a containment purge valve with a resilient seal that is i Te(u'ved /DCFR]SD, isolated in accordance with Required Action D.1, i

3 SR 3.6.1.3.5 must be performed at least once every 92 days. l dppe,vRy7[Rf.(o), This provides assurance that degradation of the resilient i seal is detected and confirms that the leakage rate of the 65 MoclM containment purge valve does not increase during the time j the penetration is isolated. The normal Frequency for Oppoved cypggttccs]SR 3.6.1.3.5 ishday+. Since more reliance is placed on a single valve while in this Condition, it is prudent to perform the SR more often. Therefore, a Frequency of once ,

per 92 days was chosen and has been shown acceptable based  !

on operating experience.

i E.1 and E.2  ;

If any Required Action and associated Completion Time cannot be met in MODE 1, 2, or 3, the plant must be brought to a MODE in which the LC0 does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and to MODE 4 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full (continued)

CLINTON B 3.6-20 Revision No. A

Attachment 5

. to U-602272 PCIVs Page 4 of 6

. 8 3.6.1.3 BASES SURVEILLANCE SR 3.6.1.3.3 i REQUIREMENTS (continued) This SR verifies that each primary containment manual i isolation valve and blind flange located inside primary l containment, drywell, or steam tunnel, and required to be '

closed during accident conditions, is closed. The SR helps to ensure that post accident leakage of radioactive fluids l or gases outside the primary containment boundary is within design limits. For devices inside primary containment, drywell, and steam tunnel, the Frequency of " prior to entering MODE 2 or 3 from MODE 4, if not performed within the previous 92 days", is appropriate since these devices are operated under administrative controls and the probability of their misalignment is low.

Two 110tes are added to this SR. The first Note allows valves and blind flanges located in high radiation areas to be verified by use of administrative controls. Allowing verification by administrative controls is considered acceptable since access to these areas is typically restricted during MODES 1, 2, and 3. Therefore, the probability of misalignment of these devices, once they have been verified to be in their proper position, is low. A second Note is included to clarify that PCIVs tha! are open under administrative controls are not required to meet the SR during the time that the PCIVs are open.

SR 3.6.1.3.4 Verifying the isolation time of each power operated and each automatic PCIV is within limits is required to demonstrate OPERABILITY. The isolation time test ensures that the valve will isolate in a time period assumed in the safety analysis. The isolation time and Frequency of this SR are in accordance with the Inservice Testing Program.

SR 3.6.1.3.5 For primary containment purge valves with resilient seals,

.Xnger additional leakage rate testing beyond the test requirements of 10 CFR 50, Appendix J (Ref. 6), is required to ensure OPERABILITY.4 Operating ^xperience has d r^,strated that J

(continued)

CLINTON B 3.6-23 Revision No. A

Attachment 5 to U-602272 Page 5 of 6 Insert to Bases for SR 3.61.3.5 (page B 3.6-23) 4 Since cycling these valves may introduce additional seal degradation (beyond that which ,

occurs to a valve that has not been opened), this SR must be performed within 92 days after opening the valve. However, operating experience has demonstrated that if a valve with a resilient smal is not stroked during an operating cycle, significant increased leakage i

through the valve is not observed. Based on this observation, a normal Frequency in accordance with 10CFR50, Appendix J (Ref. 6), as modified by approved exemptions, was established. In accordance with 10CFR50, Appendix J, SR 3.0.2 (which allows .

Frequency extensions) does not apply.

l l

~ . . -.- - - . . . -- - - . - - - .

. I Attachment 5 l

. to U-602272 PCIVs Page 6 of 6 B 3.6.1.3 BASES SURVEILLANCE SR 3.6.1.3.5 (continued)

REQUIREMENTS

-this type cf seal h:: the potential te degrade " 2 cherter time peried than de ether seal types. B::cd en thi

-observat4on r -and-the-importance cf maint+ining-this-

-penetra14en-4eak-44 9 ht (due te the direct -pat $' betweer

-pr-imary-cont-ainment-and-t-he environment 4r-a-F-requenc-y-of- l

-484-days-was-estab4 i shed . Add 444ena.lly, thi SR test-be

--pedermed within 92- days-af4er-opening the valve. 'he day-frequency was chosen-recogn424ng-thatwyc-14ng-the-va've ceuld-introduce addit 4enal-sea 4--degradat4en-{beyond-  ;

- that 'hich eccurs ta-a-valve that has-not-been-opened}- l

--Thus r-deeveas-ing-the-int-erva4-tf+om-184-days)-is-a-prudent-measure a P - ' v21ve has-been-opened. i The SR is modified by a Note stating that the primary containment purge valves are only required to meet leakage rate testing requirements in MODES 1, 2, and 3. If a LOCA inside primary containment occurs in these MODES, purge valve leakage must be minimized to ensure offsite radiological release is within limits. At other times when -

the purge valves are required to be capable of closing (e.g., during handling of irradiated fuel), pressurization  ;

concerns are not present and the. purge valves are not required to meet any specific leakage criteria. A second .

Note is added to this SR requiring the results to be evaluated against the acceptance criteria of SR 3.6.1.1.1.

I This ensures that primary containment purge valve leakage is ,

properly accounted for in determining the overall primary  ;

containment leakage rate.  !

t SR 3.6.1.3.6 Automatic PCIVs close on a primary containment isolation signal to prevent leakage of radioactive material from  ;

primary containment following a DBA. This SR ensures that t each automatic PCIV will actuate to its isolation position  ;

on a primary containment isolation signal.. The LOGIC SYSTEM FUNCTIONAL TEST in SR 3.3.6.1.7 overlaps this SR to provide l complete testing of the safety function. The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and  :

the potential for an unplanned transient if the Surveillance ,

were performed with the reactor at power. Operating experience has shown that these components usually pass this  ;

Surveillance when performed at the 18 month Frequency.

Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

(continued)

CLINTON B 3.6-24 Revision No. A

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