ML19323D814

Responds to NRC 800320 Ltr Re Violations Noted in IE Insp Rept 50-483/80-06.Corrective Actions:Review Session Held W/All Vibrator Operators Concerning Requirements of Aci 309

ML19323D814
Person / Time
Site:	Callaway
Issue date:	04/17/1980
From:	Bryan J UNION ELECTRIC CO.
To:	Fiorelli G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19323D812	List: ML19323D814
References
NUDOCS 8005220376
Download: ML19323D814 (4)

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. April 17, 1980 Mr. Gaston Fiorelli, Chief -

Reactor Construction E Engineering Support Branch U.S. Nuclear Regulatory Connission Region III -

799 Roosevelt Rd. .

Glen Ellyn, IL 60137 ULURC-348

Dear Mr. Fiorelli:

INSPECTION REPORT NO. 50-4B3/80-06 i

This is in response to your letter of March 20, 1980

"' reporting results of an inspection at Union Electric Company's Callaway Plant Site on February 27-29, 1980 and as detailcd in in-spection report number 50-483/80-06.

None of the raterial in the inspsetion report or in this response are considered proprictary'.by Union Electric Conpany; however I'-w'e do.6ffer the follouing as clarification of the last paragraph of iten 2, Concrete Placerent, contained on page 4 of the subject inspection report, which indicates that "there are no forral pro-cedures for having a preplacenent meeting on difficult pours":

Work procedure WP-109, as issued on Novenber 3, 1977, providds for preplan-

.: sing of difficult concrete placenants -

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(Paragraph 4.1.4); however, the proceduren -

' does not specify that minutes of preplan-ning neetings will become retained docunen-tation. During the NRC ey:it meeting on February 29, 1980, this subject uns discussed and the licensee agreed to review the NRC .

inspector's concern. Upon review of the procedural requirements, it has been decided ~

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to require ndnutes of pre' planning neetings to becone a part of the OA Records Package 4-for the affected pour. The procedural change '

is expected to be implenented by April 25, 1980.

The following is in response to the item listed in Appendix

- A, Notice of Violation, of the insp'ection report.

s o o e 2 2 o.s v e

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IdAY 2 1980).. .

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.o Mr0 C'ston a Fiorelli '

Apr il 17, 1980 1

, Infrnetion (493/B0-06-02) . I 10 CFR 50, Appendix B, Criterion V requires, l in part, "that activities, affecting quality '

shall be prescribed by documented instructions...

and shall bc accomplished in accordance with these instructions." ,

, a) Paragraph 10.1 of Specification 104 66-C103 (O) states, " Vibrators shall ,

1 not be used to move or spread concretc."

Paragraph 7.1 of ACI 309 states, "The

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.inyers should be as level as possible -

l so that the vihrator does not need to i

, move the concrete laterally, since this might cause segregation. "

(' Contrary to the above,.the incpectors observed on toe lower lift of concrete pour No. UC306W35 on the ESUS Pump House on February 28, 1980, in the center of -

the west wall,'that a vibrator was left in the concrete for two or three minutes to facilitate concrete movement under two blockouts in the wall.

b) Paragraph 4.2.4 of Daniel Construction Proceduro CCP-106, Revision 8 states,

" Verify Reinforcing Steel is securely tied to prevent dispfacement during cen-struction and concrete placement..."

Paragraph 7.7 of Specification 10466-C112(Q)

( ,'- , states, "Special care shall be exercised to prevent any disturban,ce of the reinforcing bars in concrete that has been recently placed." ,

Contrary to the above, the inspectors .

observed that vertical reinforcing bars ,

were untied and moved to facilitate con-crete placement for the west wall corners e of pour no. UC306W35 in the ESUS Pump House on February 28, 1980. The rebar was replaced .

and retied when the pour reached the required elevation.

CORRECTIVE ACTION TAKEN AI'D THE RESULTS ACHIEVED:

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The NRC Inspector's findings have been reviewed by Daniel Internctional Corporation (DIC) personnel.

l- . -- - Bachground information on the placement of UC306U35 -

is as follows: ,

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,. . Mr. Gaston Florelli April 17, 1980 a) During a preplacement! meeting on UC306W35, t

it was determined by DIC Ouality Control,

~ Engineering and Const'ruction personnel

'that concrete could be deposited on each end of the blockouts and caused to flow under fluid head.to the center of the blockouts. Heles were cut in the sillfof C the blockouts to facilitate vibration and to monitor concrete l'ocation. During actual concrete p3acement, the flow of the concrete was inhibited by congestion of reinforcing ,

steel and embedded itens to a greater extent than was previously anticipated. It is the bpinionrof DIC Ouality Control personnel that -

some movement of concrete by vibration did occur ::here the alternative was possible void areas. Such vibratory movement, if significant, would have resulted in segregation as the

( mortar moved ahead of the coarse aggregate.

An extensive Quality Control inspection of the completed placement, with particular attention to the blockout arcas, has indicated no signs of segregation or insufficient consolidation; therefore, it is believed that any possible vibratory movement ha,d no adverse effect.

b) In regard to the Inspector's concern that reinforcing steel was moved to accorrodate M

placement and vibration of the concrete, re-inforcing steel was shifted at the top of the subject placement to allow access for "tremie" pipes and vibrators., ~

DIC Construc' tion and , Quality Control personnel

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were fully aware of the possible consequences of shifting bars after init.'.al concrete set, and were extremely careful to revibrate the

-concrete around the shifted reinforcing steel

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af ter returning the steel to the proper location.

The Structural Quality control Inspector verified that the bars wcre correctly replaced and retied, -

and concrete Quality " Control personnel subsequently verified that the concrete was revibrated around the bars after they were returned to the proper location. . . , .

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Mr, Gacton Fiorelli April 17, 1980 j

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CORRFCTIVF ACTIO:7 TO BE TAKEN TO AVOID FURTHER Z:C:3CO."PI.IA!!CE : ,

a) The Inspector's observation that a vibrator was held in one location for two to three minutes indicates the need for a review session with all vibrator operators con-

. cerning the requirements of ACI 309.

Such a review session will be held and documented in accordance with AP-XIII-07.

b) DIC has revieued and investigated the concern of the NRC Inspector and feels the indicated iten has been satisfactorily resolved without further investigation' or action. .

DATE WIIEH FULL COMPLIld:CE UILL BE ACHIEVED:

n) Within tuo weeks after work resumes following the current work stoppage.

b) Presently in full conpliance.

If you hdve any questions, regarding this response or additional information is required, please let me know.

Yours very truly, DrQ!nal s'f.ned by go}{N N BRYAN John K. Bryan USS/jds

.) cc: Mr. W. A. Hansen '

(NRC Resident Inspector, Callaway Plant)

Missouri Public Service Commission bec: J. K. Bryan ~

m F. D. Field -

W. H. Weber (5) '

D. F. Schnell "

.R. L. Powers .

W. S. Strothman J. J. Stoecklin '

J. E. Davis ,

S. J. Seiken R. T. Davis E. U. Creel W.' R.. Bird (Consumers Power)

F. R. Hodges (Public Service Indiana)

JKB/ Chrono,_ '

QA Date" -

Nuclear Date <

AC:55A60 # -

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