ML18191A232

Attached WPPSS Nuclear Project No. 2 Mark II Containment Design Evaluation. Will Continue to Provide Updated Information on Status of Generic Mark II Owners Range Program in Support of Dffr Design Basis Information

ML18191A232
Person / Time
Site:	Columbia
Issue date:	03/18/1976
From:	Renberger D Washington Public Power Supply System
To:	Butler W Office of Nuclear Reactor Regulation
References
G02-76-98
Download: ML18191A232 (8)

Text

NRC,FORM 195 (2-78)

U,S. NUCLEAR REGULATORY COP" a ISSION NRC DISTRIBUTION eon PART 50 DOCYi&ltATERIAL DOCKET.NUMBER FILE NUMBER DR W D BUTLER WASHINGTON PUBLIC POWER SUPPL D SYSTEM.......RICHLAND, WS D L RENBEKGER DATE QE CE IVE PATE QF DOCUMENT 8-l9-ETTER ORIGINAL QCOPV QNOTORIZED UNCLASSIFI ED PROP INPUT FORM NUMBER OF COPIES RECEIVED 1 SiCIn iq ~;, =LE F~~~

LTR NOTORIZED 3-18-76..........

LTR RE OUR LTRS 4-17-75

& 4-23-75 AND THEIR LTRS 11-10-75 8 2-24-76 LTRS.........DISCUSSIN MARK II CONTAINMENT..'...ADVISING A DESCRIPTION DOCUMENT IS BEING USED TO EVALUATE THE MARK II CONTAINMENT FOR THE WPPSS NUCLEAR;PROJECT, TRANS THE FOLLOWING...,....,,...,...."

ENCLOSURE PLANT DESIGN ASSESSMENT

'FOR SRV AND LOCA LOADSA FOR

'WPPSS NUCLEAR PROJECT,NO.

2 DIST: PER MR MINER 3/25/76........

PLAIIT IIiRS: ~PPQC 4g.

SAFETY

<ASS'IGNED -AD:.

=BRANCH CHIEF:

FOR ACTION/INFORMATION ASSIGNED AD :

BRANCH CHIEF

~

ENVIRO PROJECT MANAGER; LIC,.

SST.:

PROJECT MANAGER:

LIC~ ASST.:

G FILE I &E INTERNALDISTR I BUTION BENAROYA ERNST AT.LARD SPANGLER GOSSICK & STAFF AS PROJECT MANAGEMENT BOYD P

COLLINS HOUSTON PETERSON MELTZ HELTEMES SKOVHOLT LPDR'IC ASLB EN NEER N KNIGHT S IHIIJEIL PAWLICKI REACTOR SAFETY ROSS NOVAK ROSZTOCZY CHECK AT & I SALTZMAN RUTBERG EXTERNAL DISTRIBUTION NATL LA REG, V"IE LA PDR CONSULTANTS IPPOLITO SITE SAFETY & ENV ANALYSIS DENTON & MUT.LER BR OKI VEN NATL LAB LTLRIKSON(ORNL)

OPERATING REACTORS STELLO OPERATING TECH EISENHUT SHAO BAER SCHWENCER GRIMES SITE TECH GAMMILL STEPP HUItfAN SITE ANALYSIS VOLT2IER J,

COLLLNS KREGER CONTROL NUMBER NRC FORM 195 (2 78)

I E,

, yj~W$<,

Il

+gp c,

+ +~r~~p~

Pg Ogp O

March 18, G02-76

<~~1/Pp>

LQ~

Director of Nuclear Reactor Regulations Attention:

Dr..

W.

D. Butler, Chief Light Water Reactors Projects Branch 1-2 U. S. Nuclear Regulatory Commission Washington, D.

C.

20555

Subject:

WPPSS NUCLEAR PROJECT NO.

2 MARK II CONTAINMENT - DESIGN EVALUATION II

~666b'@washington Public Power Supply System A JOINT OPERATING AGENCY S

~~

p.o.3*363 336336.wee we II *.we TP pll 63 Docket No. 50-397

References:

1)

Letter, W.

R. Butler to J. J. Stein, dated April 17,

1975, "Suppression Pool Hydrodynamic Loads.During LOCA" 2)

Letter, W.

R. Butler,to J. J. Stein, dated April.-23,

1975, "Pool Dynamic Load Due to Relief Valve Operation" 3)

Letter, N. 0. Strand,to 0.

D. Parr, dated November 10, 1975 (G02-75-310)

'"Mark II Containment Program 4)

Letter, D. L. Renberger to R.

H. Engelken, dated February 24, 1976 (G02-76-65),

"WPPSS Nuclear Project No. 2, Mark II Containment

- Design Deficiency"

Dear Dr. Butler:

This letter transmits a plant-unique design evaluation report prepared in response to NRC-Division of Reactor Licensing letters of April 17 and,23, 1975 (References 1 and 2) which requested additional information on suppression pool containment loads due to relief valve discharges and loss of coolant accidents.

A program for supplying the requested information was developed in conjunction with other Mark II Containment Owners, their architect engineers, and General Electric.

(Reference 3).

A Mark II.Containment Dynamic Forcing Function Information Report - DFFR (NEDO-21061 and NEDE-21061P) was prepared as a phenomena description document (Reference

3) which;is being used to evaluate the Mark II Containment for the WPPSS Nuclear Project No.

2.

te

0 qt;1 e

Ik"'l I

II

Dr.

W.

D. Butler Page 2

March 18, 1976 G02-76-98 Results of the design assessment indicate dynamic amplification during safety relief valve actuations, due to a couple between the suppression pool and the metal shell.

Based on our review of the results from Burns and Roe, we have concluded.the completed WPPSS Nuclear, Project No.

2 containment should be modified due to the dynamic loading.

The need for modification is based on conservative forcing functions available at this time.

We believe this modification falls under the reporting requirements of 10CFR50.55e and have notified NRC Region V'(Reference 4).

Our A'r chitect'-Engineer, Burns,,and

Roe, has identified a design mo'dification,concept that will,allow the construc-tion to continue on the remainder of the plant without precluding the ability to correct the existing deficiency.

The concept involves adding stiffening to the interior of the wetwell.

Subsequently we have analytically determined some downcomer bracing and piping in the suppression pool may require modification to their design to enable them to withstand the hydrodynamic effects of a postulated loss-of-coolant accident.

Modifications to the downcomer bracing and wetwell piping designs can be accommodated through normal design methods.

Since this deficiency is involved in a broad Mark II containment re-evaluation being performed for the Division of Reactor Licensing, we plan to continue to resolve the issue through the Division of Reactor~-Licensing.

Except where noted in the design evaluation report under "Continuing Studies,"

this report completes the responses to your letters of April 17 and 23 (References 1

and 2).

We will continue to provide updated information to you on the status of generic Mark II owners long range program in support of the DFFR design basis information.

Fifteen (15) copies of the report are attached for your review.

Very truly yours, DLR:GLG:cab D. L.

RENBERGER Assistant Director, Generation and Technology cc:

Mr. R.

H. Engelken, Nuclear Regulatory Commission, Region V

Mr. J.

G. Davis, U. S. Nuclear Regulatory Commission Attachment

0 sa f

'll F

f'

Docket No. 50-397 WPPSS Nuclear Project No.

2 Mark II Containment--Design Evaluation STATE OF WASHINGTON )

)

ss COUNTY OF BENTON D. L.

RENBERGER, Being first duly sworn, deposes and says:

That he is the Assistant Director, Generation and Technology, for the WASHINGTON PUBLIC POWER SUPPLY SYSTEM, the applicant herein; that he is authorized to submit the foregoing on behalf of said applicant; that he has read the foregoing and knows the contents thereof; and believes the same to be true to the best of his knowledge.

DATED ~~

lg 1976 D. L.

RENBERGER On this day personally appeared before me D. L.

RENBERGER to me known to be the individual who executed the foregoing instrument and acknowledged that he signed the same as his free act and deed for the uses and purposes therein mentioned.

GIVEN under my hand and seal this ~/~ day of

, 1976.

Notary Public in and for the State of Washington Residing at

~ ~

a Vl ff V ~ IIVVV<

VVV

~ o

~ ~

/

~ 9 gO r

~

f 'I 4

~

vj/

V ')

Ql

'I If