ML17275A728

Discusses NRC Evaluation of Proposed Corrective Weld at 541 Const Joint of Sacrificial Shield Wall.Metallurgical, & Welding & Structural Aspects of Proposed Girth Weld Are Acceptable.Suggests Instituting Internal Review Procedure

ML17275A728
Person / Time
Site:	Columbia
Issue date:	11/20/1980
From:	Tedesco R Office of Nuclear Reactor Regulation
To:	Ferguson R WASHINGTON PUBLIC POWER SUPPLY SYSTEM
References
NUDOCS 8012040712
Download: ML17275A728 (8)

Text

Docket No.:

60-397 l e find that the metallurgical and. welding aspects of the proposed girth weld are acceptable.

lit; also find that the structural aspects of the proposed girth weld are acceptable based on the following considerations:

a.

The corrective weld can transfer the design basis horizontal shearing forces, including the loads arising from the asymmetric load transfer path at the construction joint, without any significant reduction in the factor of safety from that previously accepted for the design using symmetrically placed plug welds-b.

The des19n criteria and nethods of analysis are consistent with those which we previously accepted for the design of the shield wall.

c.

Though the seismic loads haVe not yet been confirmed in the manner requested in a prior request for additional information (i.e.,

SEB f130.148) we can 'still reach our conclusion on this matter since the seismic loads repre'sent a small fraction of the total DISTRIBUTION.

Docket Files FSchroeder LBII1 Rdg JKnight NRR Rdg RTedesco DEisenhut VNoonan RPurple RHartfield, MPA NOV 2 0 198 BJYoungblood OELD MDLynch OIE (3)

II.Y ]

MRushbrook PCheck

,bcc:

TERA llashington Public Power Supply System LRubenstein NRC/PDR ATTN:

Mr. R. L. Ferguson ASchwencer L/PDR ftanaging Director JMiller NSIC 3000 George ltashington i<ay FMi ragl ia TIC e

k~

Post Off'ice Box 968 RIIol lmer ACRS (16@

Richland, Hashington 99352 DRoss ETC'~

SUBJECT:

STAFF EVALUATION OF THE PROPOSED CORRECTIVE HELD AT THE 541 PIIF P~

CONSTRUCTION JOINT OF THE SACRIFICIAL SHIELD HALL "C

Q

- Me have completed our review of the proposed corrective weld at the 641 foot construction joint which you propose to place on the outcr surface of the sacrificial shield wall to replace the plug welds which were previously proposed and accepted by the staff.

-This weld transmits the horizontal shearing forces arising from postulated accidents (e.g.,

pipe whip and/or a steam blowdown in the annulus between the reactor pressure vessel and the shield wall) and from earthquakes.

It is our understanding that the plug >>elds were mistakenly made to shims, placed between the mating surfaces thereby failing to achieve the structural bond between the mating surfaces of the joint. -There have been numerous submittals by you on this matter from March 1980 until October 1980.

lie have reviewed arid evaluated your submittals with particular emphasis on the structural, metallurgical and welding aspects of the proposed corrective wel do CA Cl'F4'I.g

'CD OFFICE $

SURNAME DATEP any small

'" HfL'Ct"Onange in the eismic loads he"taetow'of 'afety mt thi

~ ~ I

>ould have a

joint egligible NRC FORM 318 (9.78) NRCM 0240

~U.S. GOVERNMENT PRINTING OFFICE: 1979'289-389

0 1 /ah C 5M L

4I t ~~

C C-o 4

EI t

L g4. >>

r e~

(>

1'I

Yr. R. L..Ferguson 2

NOV 20 I9SO Based on these findings, we find the proposed girth weld on the outer surface only of-the shield wall at the 541 foot canstruction joint, to be acceptable subject to the following conditions; a.

You wiII perform and submit the results of the additional testing on the potential fire hazard associated with the welding.to be done in close proximity to the filling compound which will b'e placed in the gap at the mating surfaces of the construction joint.

This filler material is'intended ta minimize neutron streaming through the gap at this joint.

This requirement must be satisfied prior to commencing work an the proposed corrective weld.

b.

You will reanalyze the seismic loads at this joint in the manner requested in Item 130.148 and submit these results

.to confirm that there is no significant change in the sei mic loads at this joint when the soil-structure interaction is evaluated using a half-space, lumped, spring method of analysis.

This requirement need not be satisfied prior to starting work on the carrective weld.

t It should be noted that our review was focused on the acceptability of the praposed corrective weld at the 541 foot construction joint since this proposed change had the potential for reducing the factor of safety at this joint and since yau emphasized your desire to have this matter resolved first.

Accordingly, our acceptance of this specific proposed revision in the load transfer mechanism does not imply our acceptance of any other significant deviation of the as-built structure from the original design.

This statement. applies to such items as improper welds or.improper melding procedures at other locatians in the shield wall, improper concrete placement or any of the defects found by the Office of, Inspection and Enfor'cement (OIE) or by your own inspections.

Your submittal on August 19, 1980, af the rationale for leaving known defects in the shield wall was intended to address this particular matter.

However, we find that there is insufficient information in this rationale and, therefore, we cannot complete our review.

Me will forward a request for additional information on this particular aspect in a subsequent letter.

On a separate

matter, we request that you promptly inform us of any significant change in gA/gC personnel, procedures, programs or corporate responsibility prior ta implementing any changes affecting gh/gC.

Your response to this request should be made reflecting: (1) your response to our letter of Nay 18, 1900, from OIE seeking information pursuant to Section 50.54(f) of 10 CFR Part 50; and (2) your recent retention of Bechtel on the MtlP-2 project.

Me note that our review of the proposed corrective weld was delayed by a lack of.

information regarding the stresses resulting from the asymmetric load path at the 541 foot construction joint.

Furthermore, as noted above, our review of your August 19th submittal regarding the rationale for leaving existing defects in tlie shield wall indicates. that your submittal on this matter lacks both specificity and sufficient justification.

Accordingly, we recommend OFFICE)...

SURNAME OATE P.

NRC FORM 318 (9.761 NRCM 0240

'kV.S. GOVERNMENT PRINTING OFFICE: 1979 289 369

0'4 H k Jl hl

t!r. R. L. Ferguson w 3 NOV 8 0 1980 that you consider instituting an internal review procedure utilizing those members of your staff who are cognizant in the technical content. of your submittals to provide assurance that you are sufficiently responsive to our request for additional information.

1f you have have any questions on these matter s, please contact the Project Manager, N. D. Lynch at (301) 492-8413 Sincerely, Robert L. Tedesco, Assistant Director for Licensing Division of Licensing OFFICE $

SURNAME OATEN..

DL: LBItI1 ADI'.y'nch'/1 s'

'il/13/80' 8

o ngblood B.')

)SO

(( i'1 P DE!MTEB SP

/j 80"""'E:

SEB',

FSch alI@

IIq4Ao DL I RL e co" TIE)joo "

NRC FORM 318 (9.76) NRCM 0240 AU.S. GOVERNMENT PRINTING OFFICE: 1979-289.369

V J

II,J f

M I,

V JJ

ter.

R.

L. Ferguson Managing Director Washington Publi c Power Supply System'.

0.

Box 968 3000 George Washington Way Richland, Washington 99352 ccs:

Joseph B. Knotts, Jr.,

Esq.

Debevoise 8 Liberman 1200 Seventeenth

Street, N.

M.

Washington, D.

C.

20036 Richard (j. guigley, Esq.

Washington Public Power Supply System P.

0.

Box 968 Richland, Washington 99352 Nicholas Lewis, Chai rman Energy Facility Site Evaluation Council 820 East Fifth Avenue Olympia, Washington 98504 Hr. 0.

K. Earle Licensing Engineer P. 0.

Box 968 Richland, Washington 99352 Mr. Albert D. Toth Resident Inspector/WPPSS-2 NPS c/o U.

S. Nuclear Regulatory Commission P.

0.

Box 69 Richland, Washington 99352

0'

~

tt