ML18025B679

Proposed Revisions to Tech Spec 4.7.A Re Surveillance Requirements,Primary Containment

ML18025B679
Person / Time
Site:	Dresden, Browns Ferry
Issue date:	10/19/1981
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML18025B678	List: ML18025B677 ML18025B679 ML18025B680
References
IVA-BFNP-TS-168, NUDOCS 8110280271
Download: ML18025B679 (5)

Text

ENCLOSURE 1 PROPOSED CHANGES TO TECHNICAL SPECIFICATIONS BROWNS FERRY NUCLEAR PLANT UNITS 1~ 2t AND 3 (TVA BFNP TS 168) 8il028027i 8ii019 PDR ADOCK 05000259 P PDR

UNITS 1 AND 2 PROPOSED CHANGES

s ~ a vQ' c.c.A~~ 'iZF~IQ~ ~F~Tg I

4.7.A Primary Containment

l. Yrior to initial unit operat.ion.

2. At approximately three and ore-third year intervale so that any ten-year interval vouid include four

'LRT's. These inter-vals may bc extended up to <<n months if nec scary to coin-cide With refuciinp outage.

f. Except for the initial ILRT, all ILRT's shall be per-formed Mithout leak repairs imracdia rely prior to or during thc t st. If leak repairs are necessq;y in order to perfona ILRT, they shall be preceded 'by local leak measurements +here possible. The leak rate difference prior to and ll sf ter repair sn" be added to final integrated, leak rate results, L or L Pollovinp each INERT, if the measured leak rate cx:eeds L, a the conoition shell be corrected. FolloMing repairs, the integrated leak rate test need not be repeated provide" 'local leakage rat ueasuremcnts before and a.ter repair demonstrate that the'cakage rate reduction achieved by repairs reduces thc overall measured integrated leak rate to an acceptable value.

Local leak rate tests (LLRT's) shell b<<performed on the primary containment testablc penetrations .'.nd isolation valves at not less than 49.6 peig (except for the main steam isolation valves,

~ ee 4. 7. A. i) each opera-231

frow thc containment design value to take advan age oE the design leak-tightness capabi1ity of the structure over its sezvi"e lifetime. Addi-tional margin to maintain thc containmcnt in the "as built" condition is achicvcd by cst'nblishing the allowable operational leak rate. The allov-ablc operational Leak rate is derived by multiplying the maximum allow-able leak rate (49 psig Hcthod) 'or the allowable test leak rate (25 psig

• Hcthod) by 0.75 thereby providing a 25X margin to allov for leakage deterioration which may occur during the period between Leak rate tests.

The primary containmcnt leak rate tes t frequency is based on maintaining adequate assurance that the leak tate remains .Sl thin thc specification.

Tbc Leak rotc test frequency is based on the HRC guide for developing Lack race tcntinj and'urveillance of reactor containment vessels. Allov-ing thc test intervals to bc extended up to 10 months pezmits some f lexi-bility"needed to have the tests caine ide vith scheduled or unscheduled shutdown periods.

The penetration and air purge piping leakage t st frequency, along with the containmcnt leak rate tests, is adequate to allow detection of Leak-

'age trends. Whenever a bolted double-gaoketed penetrn ion is broken and remade, the cpacc between the gaskets is pressurized to determine that thc seals are performing properly. ?t is expected that the ma)ority of

,the leakage. from valves, pcnetrationo and seals would be into the zcactor building. However, it is possible that leakage into other parts of the facility could occur. Such leakage paths that aay affect significantly the consequences of accidents are to be minimized.

The primary containwcnt is normally slLghtly pressurized during period oE reactor opczatinn, 'Vftzogen used Eor incrting could leak out of the con<<

tainmcnt but air could not Leak in to incrcs~c oxygen concentration. Once the contninmcnt is filled with. nitrogen to the required concentration, determining the oxygen concentration twice a week ocrves as nn added ahsuznncc that the oxygen conc'::. ration will not exceed 4X ~

3.7.S/3.7.C Standby Cas Treatment System snd Secord r Contatnment

'the secondary containment is designed to minimize my ground level release of radioactive materials vhich might result Erom a serious accident. The reactor building provides secondary containment during reactor operation, vhcn the dryws.'ll ls scaled and in service; the reactor building provides primary containment when thc reactor is shutdown and thc drywell is open, as. during refueling. Because the secondary containment is an integraL pazt of the complete containment system, secondary containment is required at all times that primary containment is required as veil as. during

~

refueling, 274 .-