ML20066J513

Final Deficiency Rept Re Overtorqued Anchor Bolts on ECCS Pump Foundation.Initially Reported on 821019.Recheck of Torque Values to Be Performed by 821206.Sargent & Lundy 821110 Evaluation of Anchor Bolt Status Encl

ML20066J513
Person / Time
Site:	LaSalle
Issue date:	11/18/1982
From:	Schroeder C COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
10CFR-050.55E, 10CFR-50.55E, 5457N, NUDOCS 8211240353
Download: ML20066J513 (6)

Text

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." . s Commonwealth Edison O ) One First National Plaza. Chicago. Ilknois C

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(j} Address Reply Chicago, to:60690 Illinois Post Office Box 767 Novembe r 18, 1982 Mr. Jame s G. Kepple r , Directo r Directorate of Inspection and Enfo rcement - Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

LaSalle County Station, Units 1 and 2 10 CFR 50.55(e) 82-10, Final Report Overtorqued Bolts on ECCS Pumps NRC Docke t No s . 50-37 3 and 50-37 4

Dear Mr. Keppler:

Commonwealth Edison notified your office on October 19, 1982 o f a potential reportable deficiency in accordance with 10CFR50.55(e) concerning the torque values on the ECCS pump foundation anchor bolts.

This letter is provided to meet the 30 day reporting requirement for that de ficiency .

Initial review of low torque values discovered during inspec-tion resulted in the realization that the pump manufacturer lowered the torque requirement range from 2900-3000 f t .-l b. to 400-500 f t.-lb. in a 1981 instruction manual revision which occurred af ter the installation of the ECCS pumps for LaSalle Units 1 and 2. Torque checks at the site indicated that the present torque values are in the range of 2000-2500 f t .-lb.

The pumps in question were supplied under the NSSS contract and therefore General Electric Co. was requested to investigate why the GE review process for vendor manuals did not flag this torque requirement change. General Electric has indicated that this item was reviewed at the time of the instruction manual change and that calculations at that time, determined that the old torque values o f 2900-3000 f t . -lb . woul d not take the bolts past their yield point and therefore concluded that the site need not retorque the anchor bolts to the new, lower limit.

Concurrent with our notification to Region III in October, Commonwealth Edison requested that Sargent & Lundy evaluate the concern and prepare a report which would determine the present status of these ECCS pump anchor bolts (copy attached) . Initial review indicated that the present pre-load torque is adequate for all seismic and hydrodynamic loads.

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f800 8211240353 821118 HOV is %22 PDR ADOCK 05000373 S PDR

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J. G. Kepple r - Novembe r 18, 1982 The Sargent & Lundy analysis has provided the site with objective criteria for the evaluation of each specific bolt. Commencing on November 19, 1982, the site will torque check each bolt to determine if the present torque is within the specified torque range ( Attachment A). It is anticipated that both Unit 1 and Unit 2 rechecks will be completed by December 6, 1982. During these torque checks, the torque values measured will be compared to the At tachment A table values ( + 10%

column) and left "as-found" if they fall within the specified minimum-maximum range. If testing indicates that the "as-f ound" value exceeds the maximum 2025 f t .-lb. torque limit , then the bolt will be relaxed, cleaned and retorqued to a value not to exceed the 2025 f t.-lb. limit.

If there are any questions concerning this activity please contact this o f fice.

Ve ry truly yours, A-g/is/st C. W. Schroeder Nuclear Licensing Administrator im Attachment cc: NRC Resident In spector - LSCS Director o f Inspection and En forcement - Washington, D.C.

5457N

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SAFtGENT & LUNDY ENGINECRS S S E A ST MON RO E STR EE T

• CHICAGO. ILLINOIS 60003

, TELEPHONE 312 269 2000 e

November 10, 1982 Project Nos. 4266/67-00 Commonwealth Edison Company ., . - . . . . ...

LaSallo County Station - Units 1 & 2 . , . . . . . . ~ . -

Foundation Dolts . . . . . . . . s~. , . . . . . . . . _

ECCS Pumps -

Mr. B. R. Shelton . . . . . . . .

Station Nuclear Engineering Dept. . . .. - . . . . .

v'ommonwealth Edison Company . . . . . . . - . ..

P. O. Box 767 - 35 FN West. . . - . . . - , .

~ Chicago, IL 60690 . . . .. .. . . . . . - -

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Dear Mr. Shelton:

As requested by you, we have prepared the preload torque require-monts for foundation bolts of RIIR, HPCS and LPCS pumps.

Attachment "A" lists the torque values and Attachment "B" provides the design basis for torque . values listed in Attachment "A".

We recommend'that all the. pump bolts be. torqued between the Maximum Torque Limit and the Target Torque Lower Limit as listed in Attachment "A". Tho existing preload torque of the bolts are .

acceptable if they f all between the Minimum Torque Limit and the Maximum Torque Limit shown in Attachment "A". If any of the. bolts are found to have a preloading torque outside the Target Torque lower limt and mas:imum linits, they should be retorqued to a value within this range. The seismic only torque values are listed for comparison only. . . . . . ..

. . . _ . _ - . . . . Yours very truly, B. L. Pandit B. L. Pandit Mechanical Project Engineer BLPsam . . . . . . .

In duplicate . . . .

.,..a......

Attachments . . , , . . . . ,

Copics: ..m ..

T. E. Watts (1/1) ,. . . .. . . . . . . . .

G. J. Diederich (1/1) . . .. .. .

. D. L. Shamblin (1/1)  ;...........

R. J. Mazza (1/1) .. . . . . .

. D. C. Haan (1/1) . . . _ . . . . . . .

R. H. Pollock (1/1) .. . .. -

V. Reklaitis (1/1) .. . .

Y. A. Patel (1/1)

@ o -'f

3 o~ Attachment "A"

. Project Nos. 4266/67-00 -

Sargent & Lundy Letter November 8, 1982

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PRELOADING TORQUE, ft-lb -

BOLT DIA: 1-7/8" *

. MATERIAL: A-36 HPCS PUMP RHR PUMP LPCS PUMP

- Torque Wrench Torque Wrench Torque Wrench

> Accuracy Accuracy Accuracy 0% i 10% 0% i 10% 0% 10%

Maximum Torque 2250 2025 2250 2025 2250 2025 Limit (ft-lb)

Target Torque Lower 977 1086 1293 1437 1063 1182 Limit (ft-lb)

Minimum Torque Limit 642 714 792 880 512 569 Seismic Only Torque 257 286 472 525 219 244 (ft-lb) .

Notes ,

1. The maximum torque limit will induce a maximum preload stress in the bolt equal to 90% of the yield stress. .

2. The target torque lower limit will provide tensile force in cach bolt at least equal to the tensile force caused by maximum design load.

3. The minimum torque l'imit will develope su'fficient friction force at least equal to the shear force of the maximum design load.

4. "Scismic only torque" will induce a preload stress in the bolt equal to the design seismic load.

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. i ATTACHMENT 'B' (Page 1 of 2)

Summary of Stresses and Deflections in the Foundation Bolts for LPCS, RHR and HPCS Pumps Bolt Size = l-7/8" 2~

Stress ~ Area = 2.21 in Material A36 Steel s

Maximum Stress Component Maximum deflection of Pump Type in the bolts (1bs/in2) the bolts (in) Estimated duration

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f the peak load (sec)

Seismic hyna$1c Seismic + Hydro-Seismic dynamic Tensile Shear Tensile Shear

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LPCS 3589 1349 12313 5931 .419x10 ) 1.44x10~ .03

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RilR 6291 3853 14978 9174 .734x10 1.75x10~ .021 HPCS 2975 1956 11317 7437 .347x10~ 1.32x10~ .008

dOm .

• t C1.

50,000o e

" ATTACHMENT 'B' (Page 2 of 2)

U . .

.i m ,

4 40,000 o Yield Stress (published value) . . .

36,000 . . . . . . .

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32,579a D S

30,000o

+

+

~

20,000 "

4 14,978 12,313 ,

11,317 .,

10,000 o 9,174 .

7,437 I .

5,931 .-  ;

1

-  : w -4 e e e -

ou 512 642 792 97,7 1063 1293 1500 2000 2250 2500 30I00 Torque (lb-ft)

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