ML20128C463

Special Rept Re Deletion of Certain Steam Generator Blowdown Recycle Sys safety-related Hydraulic & Mechanical Snubbers. Steam Generator Blowdown Sys Mod to Be Implemented During Current Refueling Outage

ML20128C463
Person / Time
Site:	McGuire
Issue date:	04/25/1985
From:	Tucker H DUKE POWER CO.
To:	Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
TAC-55566, TAC-55567, TAC-55970, TAC-55971, NUDOCS 8505280299
Download: ML20128C463 (5)

Text

.

. 4 DUKE POWER GOMPANY P.O.150K 33180 CliARLOTTE, N.C. 28242 HAL B. TUCKER TELEPHONE nce rarsmaw* (704)373-4531

~ ~ ~ ~ " " "

y t.m 13 e 3 : I 6 April 25, 1985 Dr. J. Nelson Grace, Regional Administrator U. S. Nuclear Regulatory Commission _

Region 11 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323

Subject:

McGuire Nuclear Station, Unit 1 Docket No. 50-369 T. S. 3.7.8/6.9.2 Special Report - Snubber Deletion

Dear Dr. Grace:

The following is a Special Report submitted pursuant to Technical Specification 6.9.2 in fulfillment of the reporting provisions of T. S. 3.7.8 (Tables 3.7-4a and 3.7-4b). This report concerns deletion of certain Unit 1 steam generator blowdown recycle (BB) System safety related hydraulic and mechanical snubbers.

By my letter to Mr. H. R. Denton (NRC/0NRR) dated September 28, 1984 Duke Power Company submitted a proposed Technical Specification amendment concerning the Steam Generator Blowdown System Surveillance requirements. The hardware changes associated with the proposed Technical Specification amendment were to be implemented during the next refueling outages of McGuire units 1 and 2. This Technical Specification amendment was subsequently approved by the NRC on March 18, 1985 (amendment 41/22).

The modification of the Steam Generator Blowdown system involves removal of four motor operated isolation valves near the steam generators (lBB-140A thru 1BB-143A) along with their respective controls, instruments and leak-off lines.

In addition, all Class F piping from the containment isolation valves to the steam generators will be upgraded to piping class B. New pipe routing is more direct and reduces the number of supports / restraints required for the Steam Generator Blowdown System. An evaluation of the safety significance of the proposed modification is provided in the September 28, 1984 submittal (and in the subsequent NRC March 18, 1985 SER).

Duke Power plans to implement the Steam Generator Blowdown System modification during the Unit 1 refueling outage currently underway. Attachment I provides a list of safety related snubbers included in T. S. Tab?es 3.7-4a and 3.7-4b which are being deleted by the McGuire Nuclear Station Moditic. tion (No. MG-11433). (The modifi-cation also involves addition / modification or earious other snubbers). The pipe rerouting associated with this modification has been reanalyzed according to the applicable ASME codes to assure design adequacy. The stresses for the rerouted piping are within the allowed limits, assuming the removal of snubbers listed in Attachment I.

'tr ? ?

8505280299 850425 o &y{ !" }

r> l PDR ADOCK 05000369 di ~ > L ,h 1 S PDR

7 Dr'.' J. N21ron Grics, Regional Administrativs

., " April 25, 1985 Page '

A revision.of Technical Specification Table 3.7-4a and 3.7-4b to reflect the

. modification will be included in an upcoming license amendment request in accordance with the requirements of'the tables' footnotes.

Please feel free to contact us if you require any additional information.

Very truly yours, kb. -

/&

Hal B. Tucker PBN/mjf Attachment cc: (w/ attachment)

Mr. Harold _R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555

-Attention: Ms. E. G. Adensam, Chief Licensing Branch No. 4 Mr. W. T. Orders NRC Resident Inspector McGuire Nuclear Station l

i l.

?,

^'

' Attachment I List of Deleted Safety Related Snubbers .(Unit L1)-

Steam Generator Blowdown System-Snubber' Type Number Mechanical (M) Snubber Support No. of Snubbers Hydraulic (H) _ Size-

.1-MCR-BB-582: 1 M- 1x1500 #

- 590- 1 H 1 x3000

- 594 1 M hx650~

- 596 1 M x650

- 597 1 M hx650

- 599 ~ 1 M x650

- 600' 1- M x650

-- 601- .

1 M x650

- 603 1 M hx650

[-' o

- x650

- 604 1~ M

- 605 1 M x650 ,

{ :.

- 606 ~ l M x650

- 609 1~ M 1x1500'

.610 1 M hx650

- 772 1 M .hx650-

- 774 1 M x650

- 776 1 M ' x650

- 777 1 M x650

- 780 1 M x650

-- 781- 1 M hx650

- 783 1 M x650

- 784 1 M hx650

~786- 1 M hx650

4

.,. 'Snubbsr

. 1: Typs .

• - - - Numb:r Mech nical (M) Snubbar-

. Support No.' 'of Sn.ibbers Hydraulic (H) -Size 1-MCR-BB -788 1 M - x650 #

-790 1 M hx650

-792 1 -M hx650

-794. 1 M hx650

-799 1 M x650 t - -H1 1 M x650

-713 1 H 1 x3000

-714 1 H 1 x3000

-725 1 M x650 1

-726 1 M hx650

-727 1 M x650

-729 1 M hx650

-730 1- M x650

-732 1 M x650 1

-733 1 M x650

-734 1 M hx650

- -735 ' 1 M 4x650 l -736 1 M x650

-738 1 M 1x1500

-739 1 M 1x1500

-H71~ hx650 1 M

-658 1 M hx650 660 1 M x650 661 1 M bx650 1

671 1 M hx650 672 1 M x650

p('?c --

.v Snubbar-g; - '_.

• ~

~

, ;Typs -

-. Numbar.. Michanical-(M)' Snubbar

' ~#'

1 Support No.

. of Snubbers Hydraulic (H)- '

Size

,; l-MCR-BB- 673 1- M x6501

~

- 6 7 5 -' '1 ~M- hx650

- 676 1' ~

M x650

- 678 ~ -l' M x650

- 680 _1- ~M - x650

- 681 '1 M 4x650

_ - 683 z 1 M bx650 670 1 M- hx650 >

690 1 M- lx1500

- 691 1 M 1x1500~

F 1

4 1

i s