ML19329F881
| ML19329F881 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 07/11/1980 |
| From: | VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | |
| References | |
| NUDOCS 8007110300 | |
| Download: ML19329F881 (1) | |
Text
$ o ~7 - Il Hfteter pqutyggy g;r ACS ' t to D.1p,egog.
Admin. Officer RONS Chier '
RCES Chier-Virginia Electr'ic and Pcwer Cc:pany
~
Frus Chs.t'.
North Anna. Pcwer Station Units 1 and ? - NPF-4, UPF-7 Sfgde dhief, Cccket Nos. 50-338,60-339 P A Officer..
24 Hcur ReportJhle EVant Emgoy Qfic q, tiritten Folic.edip Q - (% < 1 pson Event: Patent',al Ncccansarvatis, in FEAR Sliery 4.11 sis. for ilacca.Gilucla.
2 Event during Cold Shutdcan LEil/fl0 Eo-055/ GIT-O curing a review of the FSAR safety analyses for tocca ui'lutian accide..-
it was dotarr.ir.ed that a potential nancanservatis.! may exist in du cold cht dcwn analysis. Sactica 15.2.4.3 states that with a baron concentratiun of 15C0 pra ar.d a dilution ficw rate of 3C0 gra, the reactor cc.ild so critic.1 in 15.5 c.inutes.
If this is cc.r. pared with the analysis for hat shi. tuc..,a o o the sra chutdan :.argin, (at least 1.771 S.) uith a tarcn ccccar,tratica.d 13C0 pra ar.d a a 1utica fica cate of 165 gra,..here ti a, m.
tc,e
- t..,
c c i t i ca'-
la 30.5 c ic...tcs, it appears that ti.a RCS valt:45
..u
- a to u t..a canditicas are ti.a sa.ia; that is, a full liC5.
This r:ay cot te-a conservative assu1ptica for the call cimiac..a c.n li t bhen the RCS cay la drained to the centerline of tha RCS iwtieg fue 1.a,
or inspection activities.
This smaller BCS vc,1we (atant 3315 ft4 n./'..
ftJ) Lauld rasult in a tira to criticality of less thaa 16.5 ' i e.a t u s :. c. 4. :
cald shu tdt...n.
Tha cause of this discrepancy is not kncan at tiiis tire.
1.'a ha'.e initistad a review of the accidant ar.11ysis i s
.t..i.. lu 1.
i.
as L pticos'in the analysis are not as conservati=sa as p.avicici) Li. c Si.e.
Unit 1 is prasEntly operating in a Staady Stata C;c.jirian at
. ', : i..
and Unit 2 is in Ecda 3 (Itot Standby).
Since par Tech. 5psc. 3.1.1.3.2, the PG valves to the b h:ca cc i e....:
veriflad tc ha Ic:ked closed within 15.inutes af ter a pha..iJ.ulat imn o.
makeup activity and the fact that neither unit is in cald 4.nuru:...a p ci6a ;
justificatian for continued operation.
Coreccthe acticns to be taken are panding cc:platica a? r...: c ru. -..c inves tig:.tica.
/Joo?.
5 I6 Yh(
8007110 300 s