U-602786, Informs That Util Has Completed All Actions Associated W/Cal Re Condition of Protective Coatings in Primary Containment & Drywell

Informs That Util Has Completed All Actions Associated W/Cal Re Condition of Protective Coatings in Primary Containment & Drywell

ML20149G987
Person / Time
Site:	Clinton
Issue date:	07/16/1997
From:	Romberg W ILLINOIS POWER CO.
To:	Beach A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
U-602786, NUDOCS 9707240159
Download: ML20149G987 (3)

Text

F

'e

• • Ilknots Power Company Chnton Power Station P O Box 678 Chnton IL 61727 Tel 217 935-6220 Fax 217 935-4632 ILLINelS PSMR u me cmm Wayne D. Romberg

^.s steni v>ce e<es>oe<.i - "eclear U-602786 4F.190 July 16, 1997 Docket No. 50-461 Mr. A. BillBeach Regional Administrator Region III U.S. Nuclear Regulatory Commission 801 Warrenville Road

. Lisle, Illinois 60532-4351

Subject:

Final Response to June 9,1997 Confirmatory Action Letter Regarding the Condition of Protective Coatings in the Primary Containment and Drvwell i

Dear Mr. Beach:

l The purpose of this letter is to inform you that Illinois Power (IP) has completed all of the actions associated with the subject Confirmatory Action Letter (CAL). These actions have been discussed previously in IP letters U-602761, dated June 12,1997, and U-602780, dated July 2,1997. Additional discussions regarding this subject were also )O, conducted during the Restart Panel meeting held July 3,1997.

In the June 9,1997 letter from J. L. Caldwell (NRC) to J. G. Cook (IP) one of j (} b the actions re c.ested by the staff was to provide reasonable assurance that, given the '

condition of the protective coatings in the primary containment and drywell, the ECCS suction strainers will remain operable following a design basis event. Enclosure "B" to that letter discussed three possible options that would address the degraded coatings issue and provide this reasonable assurance.

The first option was to perform a multiple adhesion pull test program of the subject protective coatings. The second option centered on a calculational approach to provide assurance that the degraded coatings in the primary containment and drywell would not render the ECCS suction strainers inoperable during a design basis event.

9707240159 970716 1 ig

,y,,

DR ADOCK0500g4 c,0000 <1 -

o

, .. r

. . U402786

!; Page 2 l

The third option was a combination of coatings removal activities and an adhesion pull test -

program. This third option provided the greatest assurance that protective coatings in the primary containment and drywell will not challenge the operability of the ECCS suction strainers during the next operating cycle, and therefore it is the option we pursued.

The protective coating removal activities described in our initial response to the l subject CAL (IP letter U-602761) are complete. We have removed the protective coatings in the primary containment and drywell that were identified as loosely adhered, chipping, peeling, or blistering. Th. engineering evaluation to assess the consequences of allowing some of these areas to remain uncoated during the upcoming operating cycle is also complete, and it concluded that there will be no significant impact on operation.

Additionally, our adhesion pull test program as described in both of our previous i

responses to the subject CAL is complete. It should be noted that there is an administrative error in our July 2,1997 response (IP letter U-602780). The test site experiencing adhesive failure was actually designated 7B-1, and the coatings failure occurred at site 3G-1. Nevertheless, the final results of the adhesion pull test program demonstrated satisfactory adhesion of all remaining qualified coatings in the primary containment and drywell. Subsequently, the associated engineering evaluation has confirmed our preliminary conclusion that the qualified coatings in the primary containment and drywell still meet the qualification requirements of Regulatory Guide

! 1.54. Copies of the evaluations for the coating removal activities cnd the adhesion pull

! testing are available for review.

L l As noted in the subject CAL, debris from degraded coatings is not the only l potential contributor for decreasing available NPSH for the ECCS pumps. The -

procedures at CPS to control transient and flexible material in the primary containment and drywell have been substantially revised. The extensive cleaning activities (primary containment, drywell, and suppression pool) conducted during RF-6 combined with the l amended procedural controls, provide assurance that miscellaneous debris or transient j material will not challenge ECCS pump suction strainer operability.

Also, due to the previous, indeterminate nature of the condition of the degraded coatings, as well as the previous weaknessea in the procedural control of transient and

. flexible material in the primary containment and drywell, we have determined that a reportable condition exists regarding the uncertainty of the operability of the ECCS.

Therefore, this condition is being reported in accordance with the requirements of 10CFR50.72 and 10CFR50.73.

4 i

i 1

I

h ..

.s, ei*

, , . . U-602786 Page 3

.We understand the significance of maintaining a high degree of confidence in ECCS availability, specifically as it relates to cleanliness of the primarycontainment and drywell, as well as the materiel condition of the protective coating systems in these areas.

To ensure we maintain our current level of confidence in the condition of the coatings in the primary containment and drywellmwe are initiating a preventive maintenance requirement to perform periodic coatings inspections. Additionally, a maintenance request has been written to contrcl recoating the areas where the removal work was performed.

Based on the above mentioned testing, coating removal activities, and evaluations, reasonable assurance exists to conclude that the ECCS suction strainers will not be rendered inoperable during a design basis event due to the presence of miscellaneous or coatings-related debris during the next operating cycle. ' We consider the acticas necessary to address the subject CAL as complete.

Sincerely, ,4

)9'f Wayne D. Romberg Assistant Vice President cc: 'NRC Clinton Licensing Project Manager NRC Resident Office, V-690 NRC Document ControlDesk Illinois Department ofNuclear Safety

,