ML20141K619

Forwards RAI Concerning Containment Coatings at Plant, Units 1 & 2.Response Requested as Soon as Possible to Allow Staff to Complete Review Prior to Startup of Plant,Unit 2

ML20141K619
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	05/23/1997
From:	Shiraki C NRC (Affiliation Not Assigned)
To:	Johnson I COMMONWEALTH EDISON CO.
References
TAC-M98348, TAC-M98349, NUDOCS 9705290249
Download: ML20141K619 (5)

Text

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$ May 23, 1997 I Ms. Irene Johnson, Acting Manager i i Nuclear Regulatory Services j Commonwealth Edison Company

'. Executive Towers West III

} 1400 Opus Place, Suite 500

Downers Grove, IL 60515

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION CONCERNING CONTAINMENT C0ATINGS I

). AT ZION STATION, UNITS 1 AND 2 (TAC NOS. M98348 AND M98349) '

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Dear Ms. Johnson:

By letter dated February 5,1997, Commonwealth. Edison Company (Comed or the

! licensee) provided a containment zone of influence calculation, an emergency ..

i core cooling system (ECCS) pump net positive suction head (NPSH) calculation I and Report M-00282-97 discussing the condition of protective coatings in the l Zion, Unit 2, containment.

! The staff is reviewing Comed's submittal and has determined that additional t

information, as described in the enclosure, is required to complete its j review.

4 A response to this request for additional information (RAI) is requested as i soon as possible to allow the staff to complete its review prior to the j startup of Zion, Unit 2. '

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If there are any questions concerning this RAI please contact me at

.(301) 415-3101.

i Sincerely,

). ORIGINAL SIGNED BY:L. ROSSBACH FOR:

Clyde.Y. Shiraki, Senior Project Manager Project Directorate III-2 Division of Reactor Projects - III/IV Office of Nuclear Reactor Regulation i Docket Nos. 50-295 and 50-304 pFOI J'

Enclosure:

RAI cc w/ enc 1: See next page NRC ft.E CENTER COPY DISTRIBUTION:

Docket File PUBLIC PDIII-2 r/f J. Roe, JWR E. Ad:nsam, EGAl R. Capra, RACI C. Shiraki OGC, 015B18 ACRS, TIE 26 M. Parker, RIII C. Moore C. Berlinger, 08H7 R. Wastberg, RIII A. Serkiz, T10C9 Document Name: G:\CHNTJR\ ZION \ZI98348.RAI *See previous concurrence 0FC PM:PDIII-2 6 LA:PDIII-2 SCSB D:PDIII-2 C NAME Y HIRAKI M CM00RES CBERLINGER* RCAPRA />v DATE 5/2] /97 5/ /97 5/23/97 5pF/97 9705290249 970523 >

OFFlCIAL RECORD COPY PDR ADOCK 05000295  :

P PM i

s

. -1. Johnson Zion Nuclear Power Station Commonwealth Edison Company Unit Nos. I and 2 4

cc:

Michael I. Miller, Esquire Sidley and Austin One First National Plaza Chicago, Illinois 60603 Dr. Cecil Lue-Hing

, Director of Research and Development

-Metropolitan Sanitary District of Greater Chicago

~

100 East Erie Street

' Chicago, Illinois 60611

. Phillip Steptoe, Esquire Sidley and Austin .

One First National Plaza j Chicago, Illinois 60603 ,

1 Mayor of Zion l Zion, Illinois 60099 Illinois Department of Nuclear Safety Office of Nuclear Facility Safety 1035 Outer Park Drive Springfield, Illinois 62704

U.S. Nuclear Regulatory Commission Zion Resident Inspectors Office 105 Shiloh Blvd.

i Zion, Illinois 60099 4 Regional Administrator U.S. NRC, Region III 801 Warrenville Road Lisle, Illinois 60532-4351 Station Manager

, Zion Nuclear Power Station i 101 Shiloh Blvd.

Zion, Illinois 60099-2797

Document Control Desk-Licensing Commonwealth Edison Company 1400 Opus Place, Suite 400 Downers Grove, Illinois 60515 4

4

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4

REQUEST FOR ADDITIONAL INFORMATION i i

1. In discussions with Comed, the staff was informed that a zone of '

, influence with a radius of 20 feet was selected. However, the analysis  ;

in the O bruary 5, 1997, submittal gives a variety of calculated radii for the wms of influence depending on the type of coating, some of 3 which at

eater than 20 feet. I l

! - What is.the basis for the 20 foot zone of influence?

I'

2. The February 5,1997, submittal describes a zone of influence  ;

, calculation and a net positive suction head (NPSH) calculation. The i zm of influence. calculation determined a zone of influence for each 1 paint type and the NPSH calculation predicted the largest amount of i blockage that could be tolerated without loss of NPSH. However, there l l does not appear to be a connection between the two calculations.

- Describe how the calculations are used.  !

3. Comed took numerous actions to ensure the integrity of the Unit 2

containment coatings.

i a. Describe, in detail, the steps taken to remove failed, undocumented

and unqualified coatings from the Zion, Unit 2, containment prior to

its next startup.

1 3 i b. Estimate the amount of unqualified paint remaining. .

c. . Describe any in situ testing done on the remaining coatings.  !

j 4. The analysis calculates the farthest distance from which a paint ,

particle would be transported to the sump (the radius of the zone of l influence). But the. analysis uses a radial model and does not address l j the height above the water level in the zone of influence.  ;

j_ - To what height above the ebir, ion 568 foot floor level were the  !

[ coatings removed? l

! 5. Comed has reapplied the coating to sections of the Unit 2 containment. I

a. Describe'the extent of the recoating being done in the Zion, Unit 2, containment.

b. What standards were used for this recoating? 1 I

c. Will any in-situ testir of the newly applied coatings be performed?  ;

6. The transport calculations assume a steady slow flow toward the containment sump. The coating particles are assumed to drop onto the  :

surface of the water and flow toward the sump while they are settling at i the terminal velocity.  ;

c Enclosure 1 l i j

c ,

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a. How would the turbulence due to the break discharge,. spillage, and operation of the containment sprays, occurring during and following

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blowdown, affect the amount of coating material reaching the sump? )1

b. In particular, would coatings located outside the zone of influence be swept into the zone of influence by these effects?

c. ' Justify why it is not necessary to account for these effects in the analysis.

d. What action was taken for those coatings that are undocumented, unqualified or failed that may have a calculated zone of influence greater than that selected (20 feet), or have an " unbounded" zone of influence (Table 3 of Calculation 22S-B-040M-002, Revision 1, Page

26) but that may enter the zone of influence through the mechanisms described above?

7. This-analysis does not account for any insulation debris which may be transported to the sump screens as a result of a loss-of-coolant accident (LOCA). If any coatings are assumed to reach the' sump-(i.e.,

all coatings which could reach the sump are not removed prior to the ,

next plant startup) then the combined effect of the paint and the I insulation must be taken' into consideration since the pressure drop from this combination of debris can be significantly higher than that due only to failed coatings (see NUREG/CR-6224, " Parametric Study of the Potential for BWR ECCS: Strainer Blockage Due to LOCA Generated Debris" dated October 1995; see especially Appendix B) and the method of. i calculating NPSH margin in Section 2.3 of Calculation 22S-B-008M-092 would not be correct. .

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a. Verify and provide calculations that show that the zone of influence

'is determined so that either no coatings will reach the sump or that the effect on the pressure drop across the sump screens of any that- '

do reach the sump is correctly calculated.

'b. What type of insulation is used in.the Zion, Unit 2, containment?

c. Is it a type which could readily clog screens?

8. Describe any experimental verification of the zone of influence or NPSH analyses or other relevant experimental work and provide any available documentation.

9. List and discuss any conservatisms in the Zion zone of influence  !

calculation and NPSH calculation. j

10. Explain why the zone of influence is less at a depth of 3 feet than at 1 foot or 5.06 feet of water above the containment floor. (Calculation 22S-B-040M-002, Section 7.,

SUMMARY

AND CONCLUSION.)

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l 11. Describe the Zion Foreign Materials Exclusion Program and how it .

prevents foreign r;terial (tools, . clothing, plastic sheeting, etc.) from

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clogging or damaging the sump screens. This seems especially important 3 to Zion, given the relatively small area of the sump screen.

] 12. Provide the following documents that are referenced in the February 5, 1997, submittal.

a. 5.14 of Calculation 22S-B-008M-092.  ;

t i b. 5.5 of Calculation 22S-B-008M-092. l

c. Table on page 2-10 of Reference 5.2.

d. Page 17 of Reference 5.17.

l e. Drawing of the containment sump. I

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