ML20126D898

Proposed Tech Specs Revising TS 3/4.6.4.3 Containment Hydrogen Dilution Sys & Associated Bases 3/4.6.4,Combustible Gas Control,To Add an Addl Action Statement to Apply When Both Sys Inoperable & Allow 72 H to Return Sys to Normal

ML20126D898
Person / Time
Site:	Davis Besse
Issue date:	12/21/1992
From:	CENTERIOR ENERGY
To:
Shared Package
ML20126D861	List: ML20126D858 ML20126D889 ML20126D898
References
NUDOCS 9212280214
Download: ML20126D898 (2)

Text

-. - . - . - - -. . . _ ..

Docket Number 50-346

License Number NPF-3 l Serial Number 2071

'A'ttachment

' Page 5 _

11 CONTAINMENT SYSTEug , ,

CONTAINMENT WYOROGEN DILUTTON SYSTEM i-LIMITING CONDITTON FOR OPERATION 1.6.4.3 Two'indecencent containment hydrogen dilution systems shall be

! OPERABLE.

APPLICABILITY: MODES 1 and 2.

l ACTION:

ci, ?With one containment nyorogen dilution system inocersole. restore tne /Ol-N

{

, j inoperable system to OPERA 8LE status within 30 days or ce in at least

= m _%

%AN08Y_within_the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. h ,.~ s 5 !** W =llc ,N skic 6.f L.vif4 h,%. Le% ~1 hy at lu k ou J. [vG sy 1 hs~ h cfEA.p r & Ll wo% L 71h.un i

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4Lrud

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i kwt.

1 4.6.4.3 Each containment hydrogen dilution system shall be demonstrated '

, OPERABLE at least once per 92 days on a STAGGERED TEST BASIS by: .

i

) a. Verifying snat the system can be started on coerator action in the control room, and l

i

b. Verifying that the system operates for at least 15 minutes and the blower develops a discharge pressu re of 15 psig.

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! DAVIS-BESSE. UNIT 1 3/4 6-25 9212280214 921221 PDR ADOCK 05000346 P PDR

• ' ' Docket Number 50-346 License Number NPF-3

, Serial Numbar 2071 Attachment

, Page 6 4

CONTAINMENT SYSTEMS i

. BASES i

3/4.6.4 COMBUSTIBLE GAS CONTROL j The OPERABILITY of the Hydrogen Analyzers, Containment Hydrogen 1

Dilution System, and Hydrogen Purge System ensures that this equipment will be available to maintain the maximum nydrogen concentration within the containment vessel at or below three volume percent following a LOCA.

The two redundant Hydrogen Analyzers determine the content of hydro-gen within the containment vessel. The Hydrogen Analyzers, although they

have their OPERABILITY requirements in this Specification, are considered part of the cost-accident monitoring instrumentation of Specification 3/4.3.3.5, Post-Accident Monitoring Instrumentation.

The Cont'ainment Hydrogen Dilution (CHD) System consists of two full

' capacity, redundant, rotary, positive displacement type blowers to sucoly i

air to the containment. The CHD System controls the hydrogen concentra-tion by the addition of air to the containment vessel, resulting in a i

pressurization of the containment and suppression of the hydrogen volume fraction. N' ~~

' 7~ -

p m pe b J v,1 i j The Containment Hydrogen Purge System Filter Unit functions}ee-t-I

$_ kd6 3'the CFID systMiWiTdesigned to release air from the cofi-~"

l ta'iMeist atmosphere through a HEPA filter and charcoal filter prior to  %

l

_ Alignargetothestationvent. '

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, 3/4.6.5 SHIELD BUILDING

[

3/4.6.5.1 EMERGENCY VENTILATION SYSTEM The OPERABILITY of the emergency ventilation systems ensures that j [ containment vessel leakage occurring during LOCA conditions into the-(

annulus will be filtered through the HEPA filters and charcoal adsorber l

1 trains prior to discharge to the atmosphere. This requirement is neces-sary ta meet the assumptions used in the safety analyses and limit the site bouncary radiation doses to within the limits of 10 CFR 100 during 3

LOCA conoitions.

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ha k h b Ya CHD Syk ud f Qa nt-Hy krp wy Sp% 4 e P

by % ~ nce- L b syrk~y.C,13,6 L m l4g..f ,,,L i, _ g DAVIS-BESSE, UNIT 1 B 3/4 6-4 Amenament No. 46,167 n, --- - - w - , , w e k < -- - - ,-~ ~r n>- ~v-N --. n s , w ,w