ML17037C223

Letter Requesting a Modification of Plugs in the Upper End of the Non-Instrumented Incore Housings

ML17037C223
Person / Time
Site:	Nine Mile Point
Issue date:	04/11/1974
From:	Bartlett J Niagara Mohawk Power Corp
To:	Skovholt D US Atomic Energy Commission (AEC)
References
Download: ML17037C223 (10)

Text

AEC D RIBUTION FOR PART 50 DOCKET M"'IAL (TEMPORARY FORM) 3370 CONTROL NO:

FILE PROM:

Niagara Mohawk Power Corporation

Syracuse, N.Y. 13202 Mr. James Bartlett DATE OF, DOC-4-11-74

.DATE REC'D 4-17-74 LTR MMO RPT 'THER TO:

D.J,Skovholt ORIG 1 si ed CC OTHER SENT AEC PDR SENT LOCAL PDR CLASS UNCLASS XXX PROP INFO-INPUT XXX CSRE 40 NO C'=

DOCKET NO:

50>>220 I

DESCRIPTXON:

Ltr requesting a modification to their facility described in th following enclosures......

PLANT NAME:

Nine Mile Point &i ENCLOSURES:

Figure 81 - Incore HSG Plug Layout.

t Figure fII2.

ACKNOWLEDGED (40 cys encl rec'd)

DP @OT H,KMOVF FOR ACTION/INFORMATION BUTLER(L)

W/

Copies CLARK(L)

W/

Copies PARR(L) w/

R OP'.'

KNXEL(L)

W/

Copies SCE1ENCER(L)

W/

Copies STOLZ(L)

W/

Copies VASSALLO(L)

W!

tiDPi~2 PURPLE (L)

W/

Copies NIEMANN(L)

W/g Copies DXCKER(E)

W/

Copies KNIGHTON(E) "

'/

Copies YOUNGBLOOD(E)

W/

Copies INTERNAL DISTRIBUTION REGAN(E)

W/

Copies W/

Copies W/

Copies W/

Copies REG F DR

~OGCB RKM P-506A

~TZING/STAFF CASE GXAMBUSSO BOYD MOORE (L) (BWR)

DEYOUNG(L) (PWR)

SKOVHOLT (L) r GOLLER(L)

P.

COLLINS DENXSE

~EG OPR PILE 6 REGION(3) l fORRXS STEELE TECH REVIEW HENDRIE SCHROEDER MACCARY KNIGHT PAWLICKX SHAO S TELLO HOUSTON NOVAK ROSS IPPOLITO TEDESCO LONG LAINAS BENAROYA VOLLMER DENTON GRIMES GRfMILL KASTNER BALLARD SPANGLER ENVIRO MULLER DXCKER KNIGHTON YOUNGBLOOD REGAN PROJECT LDR HARLESS

'IC ASST

~DXGGS (L)

GEARIN (L)

GOULBOURNE (L)

LEE (L)

MAXGRET (L)

REED (E)

SERVICE (L)

SHEPPARD (L)

SLATER (E)

SMITH (L)

TEETS (L)

WADE (E)

WILLIAMS (E)

WILSON (L)

A/T XND BRAHMAN SALTZMAN B.'URT PLANS MCDONALD UBE w/Input INFO C. MILES B. KING (E/W-358)

KLECKER EISENHUT

~g. Coupe EXTERNAL DISTRXBUTXON (I) (2X10)-NATIONALLAB'S I-ASLBP(E/tP Bldg,Rm 529) 1-W.

PENNINGTONP Rm E-201 GT 1>>CONSULTANT'S

. 'NEflMARK/BLUME/AGBABXAN 1"GERALD ULRIKSON...ORNL 1-'B 6: M SWXNEBROAD Pan E-201

~ - LOCAL PDROswego, N,Y'. p Vl - TXC (ABERNATHY) v1 - NSIC(BUCHANAN) 1 - ASLB

- Po RE DAVIS (AEROJET NUCLEAR)

~6 -

CYS ACRS iT'~~N( Sent to Teets 4<<17-74 1-PDR"SAN/LA/NY 1-GERALD LELLOUCHE BROOKHAVEN NAT.'AB 1-AGMED(Ruth Gussman)

>~- B-127, GT; l-IJ)..MULLER;.F-309 GT GT

~ -g SKI

'egg 'g

~

ll I'I,

$f'r gg

~

~ I g

~

~

~ ~

~

~

I

)

II i

~ ~

NIAGARA MOHAWK POWER CORPORATION AIIIIII,,

NIAGARA~

MOHAWK 300 ERIE BOUI.EVARD WEST SYRACUSE, N,Y. I3202 April 11, 1974 Mr. Donald J. Skovholt Assistant Director for Operating Reactors Directorate of Licensing United States Atomic Energy Commission Washington, D. C.

20545

'ear Mr. Skovholt:

Re:

Nine Mile Point Unit 1 Docket No. 50-220 lp yO

/pe 4gg 1g

@<It P+8y

+og~~<crlug C

C~~

Pursuant to Section 50.59 of the Commission's Regulations, Niagara Mohawk plans to make a change in its facility under. Provisional Operating License No. DPR-17.

Briefly, this change consists of installation of plugs in the upper end of. the non-instrumented incore housings.

The modification is designed to prevent the accumulation of radio-active scale in the non-instrumented incore housing flanges under the reactor vessel.

The scale accumulation in these housings produces high radiation levels under the vessel and interferes with control rod drive maintenance operations.

The proposed facility modification provides for installation of plugs in the upper end of the non-instrumented incore housing as shown in Figure 1 attached.

This will prevent the accumulation of radioactive scale in these incore housings.

The four fuel assemblies surrounding the incore housing would be removed and the plug inserted.

As can be noted from the attached figure, a fluid path is provided through a screen into the core housing from the area between the upper and lower core support plates.

This will prevent any pressurization force buildup within the incore housing by providing equalized pressures in and out of the tube.

The plug assembly cannot be forced completely out of the incore housing due to the normal positioning of the fuel assemblies and the length of the plug assemblies.

The twenty-two spare incore housing locations are shown on Figure 2.

j I

l<

1 j

Mr. D. J. Skovholt U.

S. Atomic Energy Commission April 11, 1974 The facility modification has been reviewed by on-site and off-site safety review committees who concur that the modification is in the best interest of maintaining a high degree of safety and reduction in personnel exposure.

Very truly yours, James Bartlett Executive Vice President

/sz

'I jc tr'

0 h

~ r B

e 7?D'/PHD. FVKSUZEZZ:..-'

'COIFF SUPPORP-.-.

'I

/go-z-a Z-/- 7+

/FIWAI6 j/5+

j4yOK~

TT JJ J

I

~

I I

~

I IhfC&I'CiIOUSI4'G l

lhf:COiPEIlOUSfiV8XLUG' Q

~

'FUFCASAI g Z.O92 P2 ~ 4S75 7YP

0 "J

'I 1

II t'

lt

~ I

o le I ~

~

s SR 551 F85%

%8558

~5 RE illl k I

I

~

~

~ '

~

Cl

~

J

~ o a

s W

5 S55 ea ~

acme wa

~w~'ISM~

R o

~

0

~

I

h T

~

~