ML20148T131

AO 50-219/74/34:on 740528-29,leakage Observed in Vicinity of Incore Flux Monitor Tube & Incore Flux Monitor Housing Penetration Located at Reactor Vessel Bottom.Cause Undetermined.Nsss & Mfg Contacted Re Corrective Action

ML20148T131
Person / Time
Site:	Oyster Creek
Issue date:	05/30/1974
From:	Sullivan J JERSEY CENTRAL POWER & LIGHT CO.
To:
References
AO-50-219-74-34, NUDOCS 8102190748
Download: ML20148T131 (3)

Text

• < < **'s m wwwuw'w.

, Heport,u:a.u;

~

'N

,c

. DYS7hR CREEK NUCLEAR GENERATING STN110N~ '

PORK,BD RI\'BR, NEtt JERSEY - 087311 ,

.. s. .

- 4 -

. Abnoroal Occurrence v ., f

.. 50-219/74/ 34

.. .'. Rep; ort .No. .

, .i. .-

IDENTIFICATION-

' Violation of-ths Tcchnical Specifications, mar'agraph N/A ,

0P' OCCURRENCE:

Indications.of coolcat 1cchage existing in the area or u x 'incore flux ocnitor reactor vessel housing located at core coor-c- (

. dinate 28-05. ,

f. ..  :. .

1 y ,n .

1

... , . , . , 1 1 ,

. c.

,a .

i o Ris event is considered to be an abnormal-occurrence as de-fined in' the Technical Specifications, paragraph 1.15E _.

., , n ..

' 00NDITIONS PRIOR .

. i Steady State Power' Routino Shutdown TO OCCURRENCE:

• Hot Standby Operation .

• Cold Shutdown _ Load Changes During x- Refueling, Shutdown Routine Power Operation

.s Routino Startup Other (Specify)

. Operation

7. ' ' h.e ivactor was in the REFUBL coda during'a hydrostatic test at'.850 p'sig pressure and with. coolant' t'e:gerature approxicctely -

~

U ..: . ..- >*-

.- 15,5'Pvc .s

.rv. ., . . .

y -

.w . .

,- .s t'

. . c. s.

r D$5CitIPT10N On Tuesday, Hay 28, 1974, during a scheduled reactof v6ssef'"

0F OCCURRENCE: .

hydrostatic test to inspect the' pressure boundary following .

. s.

. 7,. ,

- refueling raintenance activities, Icakage was observed in the vicinity of an incore flux conitor tube located at the botte:s of the reitetor vessel. 'Further investigatico conducted on Wednesday [ Hay 29, 1974, showed evidence of possible Icakage

- in the area of an incere flux monitor housing penetration

,  ; (

c . .

f/dM[g 9% "

THIS DOCUMENT CONTAINS POOR QUALITY PAGES

7 t

,/ . . .

. r; ,

.Isca%d in the reactor vessel bottou r. cad. A second hydro-o ..,.(.- ' .

. 3- .,

i .% . static test was ccmducted'at a pressure of 850 psig at approx 1'-

L . ,

. y ..a . , . . .e . ..,,,.... .. . . . . . . . . . g .f . 3 .- . .g , . . . , , . . , , , , , ,

- e, E

t. .,

.. .mately,.a.,. ,.. . . ... . . t8.7. . 0 .s 0',p,s c.cn; !. - A w. y y ..29 A,1074

+. . ..

- observed leaking between'the monitor housing and the reactor vessel. he leakage was measured under the conditionss of 850 I .,-

s- . 3,1

, psig with. a terperature of 164"F, and calculated to be on. the

, ?: .

. order of approxicately 0.02 gallons per hour.

APPAPali CAUSE Design -

Procedure OF OCCURPECE: Manufacture Unusual Service Condition

. Installation /. Inca Envizcatental-l

' Construction- Corponent Failure

-Operator . Other (Specify)

. . .u ,

.s

. 1he cause of this event has yet to be'dstermined; i

ANALYSIS OF . As stated in FDSAR A"endt:ent #37, a postulated failure of the OCCUP2 5 CEi l.2

- > flux monitor tth would result in vessel leakage at a rate

.. k . .:s .....m.... .:, .: , . ..:, vh . . .a

~ .,

. which would not cause excessive cladding <ter7eratures and for which core reflooding is p'ossible by engineered safety features.

U 1his situation is less severe than the design basis accident.

s.,

To determine the consequences of a weld failure at a housing

. .c i .

for an in-core conitor tube, it'is assumed that the weld between the housing and the reactor vessel bottc:a head fails, allowing the housing and the in-core monitor tube tobc ejected from the

. < .. l

'. ., vessel. The hole provided in the botto:n head for the housing has a diameter of two inches; this is the assdmed break size.

1he hole has a break area of .0218 ft 2. Assuming worst condi- )

..i.

. tions, this results in peak clad tc::peratures less than 1000 F,

~<. as'ipdated in FDSAR Ar..ndment #67. 'Ihis yalue is well within zl . .

acceptablo li=1ts of the applicable ECCS criteria. 3, n, ,

.c..,-.-...~ .~- . - . . .

.m X-1he n"' tar steam supply vendor and t9 reactor vessel manu-CORRECTIVE ACTICd: b facturor have been ccatacted with rogar'd to this conditi'on.

k Discussion will ensue as to the proper course of action to be taken to resolve this patter. Reco::cendations will be forth-coming pending cc:plete review of this event by the Plant Opera-A '-

- tions Review Co:mittee. , , .

s .

,. ... , . . . ... e, A... .. .

p>

i

..; 3,~ ., .

, . t ,. .

. ,3

.i

.  : 3.

pi

,.o;..

,, ,, ( ;il . '-

N

. j Prepared 'by; [

' N N, Dato:- 5/3_0/74

, i i l Q -

' .d a. .

d e.

e 9

e O

e I

I L

N q w

? >

1 I

~ ;jQ

.-u 3

m-P' ,}g .., .

gm.

'h (g 7-..F,-M ,g...'g",1ge,=

, TTTV N

'A'

' f,hg. ',7 7W 7 p # I- V7 '

.;R

. ' $'> ' W'n \tf. .-g . ,

j, f ., G 7Q.f ;gg..g4;y Wp}U, T s 1

. ' Y',,7 ?.4?l1,h,'l.

3'. 5,{w .,g .e,n' ' o?a? ? . g., a,. v. p u ,-~gg - %. g' "y.' .y g . 7sg' ].g.gp'.;

s w <,,g ,9,. ),,.,'S 9 y;g qqq.;f,c ?hil'd ~.-

gy- g..qq..

. .~ ,, , ,

9, . s