ML20058K982

Application for Amend to OL Application Re Proposed Mods to Sensitized Stainless Components Attached to Plant Nuclear Pressure Vessel

ML20058K982
Person / Time
Site:	Monticello
Issue date:	05/07/1970
From:	Mcelroy D NORTHERN STATES POWER CO.
To:
Shared Package
ML20058K441	List: ML20058K439 ML20058K982
References
NUDOCS 9105070334
Download: ML20058K982 (5)

Text

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Regulatory File Cy. \

i UNITED STATES ATOMIC ENERGY COMMISSION 88"i<ad wMr we3 MO t

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NORTHERN STATES POWER COMPANY l* Monticello Nuclear Generating Plant. E-5979 Docket Number 50-263 1

't s-AMENDMENT NO. 26 5

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i' APPLICATION FOR AEC CLASS 104b OPERATING il LICENSE FOR A UTILIZATION FACILITY l

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!1 Northern States Power Company, a corporation organized under the laws of the State of Minnesota, applicant for an operating 4

j license for the Monticello Nuclear Generating Plant, hereby amends its application by submission of Amendment 26.

Amendment 26 describes our proposed modifications to sensi-tized stainless components attached to the Monticello nuclear pres-I-

sure vessel. -

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This Amndent to the application contains no restricted or i other defense information.

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4 Dated May 7, 1970 l

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NORTHERN STATES POWER COMPANY D

By .L 7

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D. F. McElmy 1

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STATE OF MINNESOTA)

COUNTY OF HENNEPIN) f!

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D. F. McElroy, being first duly swom, says that he is the '

Vice President-Engineering of Northern States Power. Company, a corporation organized and existing under and oy virtue of laws l of the State of Minnesota, that he executed the foregoing appli-cation for amendment for the purpose therein set forth; that the l statements made in said application for amendment are true and-correct to the best of his knowledge and belief; that he was l

- authorized.to execute said application on behalf of said corpo-ration; and that the seal affixed is the corporate seal of said f I

corporation. I l

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D. F. McElroy Subscribed and sworn to before me This day of May ,1970 l:

I/ i Robert E. Hessian Notary Public, llennepin County, Minnesota-l i

l My Commission Expires May 15, 1976 \

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..d A O AEC Docket No. 50-263 4 -

M/d S 1970 ~ C Regulatory File Cy.

A!ENDMENT 26 Receivsd w/ Lit Calad IY"[O N 8

! #h i l-4 This amendment describes propueed modifications to the furnace sensitized stainless steel l components attached to the reactor pressure vessel. Table 1 lists the components and

> aummarizes the type of modifications. A description of the types of modifications follova Table 1.

TABLE 1

) Proposed Component Spec. - Grade - & Condition Modification j HlA & N1B Recirculation Outlet SA240-Tp30h - Solution heat treated Clad ID only Nozzles Safe End Rolled and Welded Furnace Sensitized N6A & N6B Top Head Instru- SA182-F3Oh - Solution heat treated Replace mentation Furnace Sensitized Long veld neck flange NT Top Head Vent SA182-F304 - Solution heat treated Replace Long veld neck flange Furnace Sensitized N8A & N8B Jet Pump Instrumentation SA336-F8 - Solution heat treated Replace Nozzle Safe End Furnace Sencitized N9 CRD Hydraulic S'ystem SA336-F8 - Solution heat treated Replace Return Nozzle Safe Furnace Sensitized End j 20 Weld buildup of SA298 Type 308 - Weld metal overlay existing Jet Pamp mounting pads Furnace Sensitized mounting pads and attachment velds l 32 various sizes - veld build- SA298 Type 308 Weld metal overlay Pad and l up of mounting pads Furnace Sensitized attachment veld ;

i Description of Modifications i

! Replacement of Furnace Sensitized Stainless Nozzle Safe Ends and Long Weld Neck Flanges - j

! Safe ends for nozzles NdA, NdB, & N9, and long veld neck flanges for N6A, N6B, & NT, vill l

! be removed by machinin6 in a manner such that the veld buttering on the ferritic nozzles vill not be disturbed. -

1 J Replacement safe ends are SA336-F8 forgings. Safe ends for N8A and N8B are each comprised- l of two half section forgings requiring two longitudinal velds. All replacement' safe ends" ; j l meet quality control requirements equal to those required in the original fabrication, i.e., i j USAS1 B31.1.0 upgraded to meet ASME Section 3 requirements in regards to materials, velding,

, non-destructive examinations and documentation thereof.

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All velds vill be liquid penetrant examined and radiographed. In addition, a new baseline I examination,which vill be used as a reference for future inservice examinations, vill be l performed utilizing ultrasonic testing methods.

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] Cladding of Recirculation Outlet Nozzle Safe Ends - Safe ends for recirculation outlet nozzles ,!

1 NlA and N1B will be clad on the inside with SA295 - Type 308L. The inner circumference of

-tha safe end is marked in 9CP segments. These provide' reference lines for the velder'to 'l follow in depositing his initial veld bead in each quadrant. Sequencing is such that; _

i longitudinal beads are deposited in groups of four in alternating quadrants to maintain minimum interpass temperatures. Each veld bead is approximately 10}" long and covers the j entire safe end plus an overlap of the sensitized buttering on the ferritic nozzles and .;

the primary coolant piping. t

• t Liquid penetrant examinations using fluorescent penetrants vill.be performed both before j and '.fter veld overlaying. Any indications discovered as a result of the liquid penetrant  ;

examinations vill be removed.  ;

Cladding of the O.D. surfaces of these safe ends is not planned until such time there is I l

reasonable assurance that this overlay would not interfere with future inservice ultrasonic  !

examinations. These outer surfaces vill be cleaned and liquid penetrant examined. Another l baseline inspection vill be performed using ultrasonic methods. This baseline vill be used  ;

. as a reference for future examinations. '

J Overlay of Mounting pads - The existing mounting pads and attachment velds which are j identified below, vill be overlay clad with SA298 Type 308L.

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,, i 20 Jet pump mounting pads 4 Steam dryer hold down pads ,

d 4 Steam dryer support pads  !

j 2 Guide rod pads l 4

8 Feedvater sparger line pads i 8 Core spray piping pads 6 Surveillance sample holder pads (I a! Additional bracing for each of the 10 jet pump risers vill be installed. The bracing material is Type 304. Twenty new mounting pads and attachment velas vill be SA298 Type 308L..

f All veld surfaces vill be liquid penetrant examined both before and after veld overlaying. {

Any indications discovered as a result of the liquid penetrant examinations vill be removed. '

Jet Pump Replacement Castings - Spare non-carburized jet pump castings have been delivered.

I- and vill be installed during the afore mentioned modification program.

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