ML20091K369

Proposed Tech Spec Changes Re Use of Containment Vent & Purge Valves

ML20091K369
Person / Time
Site:	Peach Bottom
Issue date:	05/29/1984
From:	PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:
Shared Package
ML20091K349	List: ML20091K346 ML20091K358 ML20091K369
References
NUDOCS 8406070038
Download: ML20091K369 (4)

Text

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PBAPS LIMITIN'G CONDITIONS FOR OPERATION

_ SURVEILLANCE _ REQUIREMENTS 3.7.D Primary Containment IsolajI5n valves 4.7.D Primary Containment IsoIajlon_ valves

1. During reactor power oper-

1. The primary containment

'ating conditions, all isola-isolation valves surveillance tion valves listed in Table shall be performed as 3.7.1 and all instrument line follows:

flow check valves shall be operable except as specified

a. At least once per in 3.7.D.2.

operating cycle the operable isolation valves that are

2. In the event any isolation power operated and automatically valve specified in Table initiated shall be tested 3.7.1 becomes inoperable for for simulated automatic isolation, maintain at least initiation and closure one isolation valve operable times.

in the affected penetration that is open and either:

b. At least once per quarters

a. Restore the inoperable valve to operable status within 4 (1) All normally open power hours or operated isolation valves (except for the

b. Isolate the affected penetra-main steam line power-tion within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by operated isolation use of at least one deacti-valves) shall be fully vated automatic valve secured closed and reopened.

in the isolation position *, or (2) With the reactor power

c. Isolate the affected penetra-less than 75% trip main tion within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by steam isolation valves use of at least one individually and verify closed manual valve

• or closure time.

blind flange; or

c. At least once per week the

.d.

Be in at least Hot main steam line power-Shutdown within the next operated isolation valves 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in Cold shall be exercised by Shutdown within the partial closure and following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, subsequent reopening,

d. At least once per operating cycle the operability of l

the reactor coolant system instrument line flow check valves shall be verified.

• Isolation valves closed to

2. Whenever an isolation valve satisfy these requirements may listed in Table 3.7.1 is be reopened on an intermittent inoperable, the position of basis under administrative at least one other valva i

control.

in each line having an inoperable valve shall be recorded daily.

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PBAPS LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS ____,,_

3. The isolation valves specified in Table 3.7.1 shall be demonstrated to be operable prior to returning to service after maintenance on or replacement of the valve, actuator, control or power circuit by performance of a cycling test, and verifica-tion of isolation time.

3.7.E Large Containment Ventilation 4.7.E Large Containment Ventilation TiBIEEI5H THIves fiBIItT55 viIves

1. The 18 inch containment

1. The inflatable seals for ventilation isolation the large containment venti-valves shall be operated in' lation isolation valves accordance with specifica-shall be replaced at tion 3.7.D and with specifi-least once every third cations 3.7.E.2 and 3.7.E.3 refueling outage.

below.

2. When the reactor pressure is

2. The LLRT leak rate for greater than 100 psig, the large containment the reactor critical, ventilation isolation and the reactor mode valves shall be compaared to the switch in the "Startup" or rate to detect excessive "Run" mode, primary contain-valve degradation.

ment purging shall be subject to the following restrictions:

a. The time a flow path exists shall be limited to a combined total of 180 hours0.00208 days <br />0.05 hours <br />2.97619e-4 weeks <br />6.849e-5 months <br /> per calendar year for both units (Peach Bottom Units 2 and 3) except that unused time (difference between 180 hours0.00208 days <br />0.05 hours <br />2.97619e-4 weeks <br />6.849e-5 months <br /> and actual annual purging time) may be carried over to following years, provided that the total purging time for both ur, is in any one year does not exceed 270 hours0.00313 days <br />0.075 hours <br />4.464286e-4 weeks <br />1.02735e-4 months <br />,

b. The flow paths subject to this specification are listed below:

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P2APS LIMIIIE9_E9E91TIggS_ggg_ggggAI1gg________SggvgigpAggg_ggguigggggIg Penetration Flow Path valves N25 AO-2505 - AO-2520 AO-2519 - AO-2520 N26 AO-2506 - AO-2507 N205B AO-2521A - AO-2521B AO-2519 - AO-2521B N219 AO-2511 - AO-2512

c. Only one of two SGTS trains shall be used for containment purging at a

time,

d. Both SGTS trains chall be operable when purging contain-ment under the above conditions.

3. At least one large containment ventilation isolation valve shall remain closed, except when needed to purge as permitted by specification 3.7.A.5.b, or for any other safety-related reason.

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,h h !_!_ h h 8_E M I.s karge Containment ventilation valves 1

'The containment ventilation isolation valves are subject i

to the restrictions of specification 3.7.E.2 to limit the total time that a flow path exists through certain containment penetrations.

The limit ensures that the average annual purging time per unit remains below 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> (14 of a calendar year).

Consequently, the impact on plant risks resulting from a LOCA while purging and the ptential for failure of the Standby Gas Treatment System contribute little to the likelihood of an uncontrolled radioactive release.

i Additionally, containment purging is permitted only for t

safety-related reasons.

The NRC guidance considers safety-related reasons to include inerting, de-inerting, and pressure t

control of the containment environment.

The guidance excludes purging for humidity and temperature control.

l The T-ring ir4flatable seal in the valves assures very low rates of leakage.

Following vslve closure, the anal chamber is automatically pressurised, establishing a tight seal against the periphery of the closed butterfly disc.

The seal is subject to some compression set over a period cf time due to radiation i

and temperature effects.

This phenomena will not be a problem for the Peach Bottom valves because the inflatable T-ring seal maintains a constant and uniform sealing compression.

However, as a preventive maintenance measure, the seals will be replaced i

overy* third refueling outage, which approximates the t

manufacturer's recommendations of every four years, it i

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