ML20086D702
| ML20086D702 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 11/13/1973 |
| From: | Riley B VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8312020460 | |
| Download: ML20086D702 (3) | |
Text
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M V EIO10 NT Y A N i{ 10M N UcLEA1 Pow ER CORIM31? ATION (h
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SCVEt41Y ULVEN GHOVL STHECT RUTI.AND VEltMONT 03701 REPLY TO:
VYV-3070
,,, o gox m VERNON. VERMONT 05364 November 13, 1973
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1)irectorate of Licensing UOP pg \\g 52 yb
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REI EllENCE:
Operating License DPR-2S js %4
,.4, Docket No.30-271 O/' -
i SullJECT:
t:ont a inment Leak Rate Testing
Dear Si r:
1:
ceareance ei th Technical Specification:, for the Vermont Y:mL ei
- e l e rr Pe.
Station, xc etl un 6. 7. il 2.b, we a re reporting the follo i n;' subst ant i:,1 va r i ance i' rom performance specifications qiven in ',cc: ions 1. 7..i. 2. n rinti 4.7.A.2.1.
Ce:.t ai r 14 i:olation V.Ives Du ri a the R: 11 l'R recu titutien cutago, thret p r i nary c on t a il::
I.i s o l a t ! O valver \\lcre
'o'md te h::ve seat leakace in ei s M h at, e: <tted l'y th it eanical Speci ficaricos as a re milt u'
thi, cicat, the thr;"
v.. cey, e re not capable of perfaraing thei: s'mt cion o c i r a r;. cant:in,
'solut.i nn t:i th 3 nd ivi dual vaIve Ic.,'.r o t' is ti that 2e.airm! W Te Anical Specifications, t1-ill 'al f ora.! t e inire lu i.; c r, rent e r t!. n that ' ' l c~.e ab i c,
s eco:9 i n i s the :c: (
line n.oiided tio prepe r pri t ne ry con t :ti nre n t 1: o l a t i e-m
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We thret valves :md 1hei r "a3 found' len ge n t <-
re fullew
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L: nL.me l'a t e Dat e of Evtat V-10-iP-6i i nd e t t r:::i n ab ic 10/16/73 (Dc
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8312O20460 731113 PDR ADOCK 05000271 P
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COPY SENT REGION
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i VERMONT YA.
.CC NUCLCAR POWER CORPORATION e
i Directorate of Licensing November 13, 1973 i
Page 2 i
As Found Valve Description Leakage Rate Date of Event i
V-2-86A
>40 SCFil 10/8/73
("A" ?!ain Steam Line Isolation Valve Outboard)
V-2-86C
>40 SCril 10/12/73
("C" ' fain Steam Line Isolation Valve Outboard) i Corrective Action
+
4 Disassembly and inspection of V S6A and V-2-86C revealed an accu:nulation of scale on the valve seating surfaces. The main valve discs were lapped and the seating rings were honed and dressed.
The pilot discs were ground and lapped by hand.
Pilot valve seating rings w:ere also lapped.
Following these repai es, the Icakage rate pas t V-2-S6A was 0.4M SCni on Norc;.her 10, 1973, and that past V-2-G6C was 6.75 SCFil on Nove,aber 8.1973.
i I
hisasst sly and inspection of V-16-19-6A revealed an necumulation of s cale on the "alve seating surfaces. The valve dise w ", cleaned and the seating ring.<as replaced.
Follo.-cing these repairs, the leakage j
rate pas t the..tive was 1.28 SCril or.380 lbm/hr en October 19, 1973.
J l
Can, ai n:. ent P",s'.
.'!ak eun 'Jalve V 20- J B was t'et nd t o be Installed with the over the seat side on the up:tteu. s i d e ot' t he s. st em ( te..a rd the nit rogen " heup source).
1 ;., f nat
- c., : stent ui t h iso l at : on ', t ive cri t e ri a, i.e.,
an isolation i
ra:ce eats 1Je
..e cent: n: at insta! !cd such t'. ::t when perfore.ing the sela t ien furu t len,,'reuu ' : ron the prinary cont ainment is applied over the see mnd ten:!: to close the valve.
1 j
The failure of V-16-J0-22f, to be installed correctly presents an 1
abnor 21 degra d n ion of er.e of the wveral boundaries which are designed to contain the radioacti cc atterials resulting fron the ti.c;ica process.
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I co r re c t i ve M i en
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U-16-20 "2B uas installed prop rly such that any pressure frcu the cont-in. ai is applied ove: the seat tending to close the valve.
Fo i los i n3' ti:
Installatica, the leak: ige rate past the val.ve was 0.416 SCRI On NOri
'W T 3, 1973.
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VERMONT YAN. _-
NUCLEAR POWER CORPORATION Directorate of Licensing November 13, 1973 Page 3 f
Drywell licad Access flatch On October 23, 1973, while attempting to pressurize the doubic gasketed seal on the Drywell IIcad Access llatch, gross pressure decay was observed between the gaskets. A check of the access hatch with
" Snoop" indicated leakage through the outer gasket.
Visual inspection of the gaskets showed that the outer gasket was brittle and would crack when pulled, but the inner gasket was less brittic and still had some resilience left when it was pulled.
Corrective Action Both gaskets on the access hatch were replaced, the hatch tested -
and verified to have :cro Icakage on November 2,1973.
Very truly yours, VERMONT YANKEE NUCLEAR PONER CORPORATION sb.W-B.W. Riley Plant Superintendent WFC/kbd
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