U-600814, Provides Addl Info Resolving Concerns Noted in Sser 8 (NUREG-0853) Re Use of Silicone Sealant in HVAC Sys Filter Housing.Sealant Found in Filter Housing Conduit Penetrations Will Be Sealed Inside Conduits W/Bisco Sealant Matl

Provides Addl Info Resolving Concerns Noted in Sser 8 (NUREG-0853) Re Use of Silicone Sealant in HVAC Sys Filter Housing.Sealant Found in Filter Housing Conduit Penetrations Will Be Sealed Inside Conduits W/Bisco Sealant Matl

ML20212P902
Person / Time
Site:	Clinton
Issue date:	01/23/1987
From:	Spangenberg F ILLINOIS POWER CO.
To:	Butler W Office of Nuclear Reactor Regulation
References
RTR-NUREG-0853, RTR-NUREG-853 U-600814, NUDOCS 8702020082
Download: ML20212P902 (3)

Text

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U-600814 L30-87 (01-23)-L 1A.120 ILLINDIS POWER COMPANY CLINToN POWER STATION'. P.o. BOX 678, CLINToN. ILLINots 61727 January 23, 1987 i

Docket No. 50-461 i

! Director of Nuclear Reactor Regulation Attention: Dr. W. R. Butler, Director

• BWR Project Directorate No. 4 Division of BWR Licensing l U. S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Clinton Power Station (CPS) - Resolution of Uncontrolled Use of Silicone Sealant in Ventilation Filter Housings

{

Dear Dr. Butler:

The purpose of this letter is to provide information to the Staff on Illinois Power Company's (IP's) proposed action plan to resolve concerns 4

over the use of silicone sealant in affected Heating, Ventilation, and Air l Conditioning (HVAC) system filter housings. This information was discussed ,

l with Mr. B. L. Siegel and Mr. J. Lee of your staff on January 6, 1987.

During walkdowns of various HVAC filter housings, inspections for "

i uncontrolled / inappropriate use of silicone sealant material indicated that several filter housings were affected. Sixteen of the seventeen housings i inspected had silicone sealant material in conduit penetrations and five i housings had silicone in the interior of the housing. The specific systems affected and details associated with each are identified in the Attachment to this letter.

IP's proposed corrective action plan and schedule for completion are I as follows:

! 1. Corrective Action Plan For the instances where silicone sealant was found in the associated filter housing conduit penetrations, IP shall seal inside the conduits with BIGC0 sealant material. BISCO sealant is qualified to the fire protection and environmental conditions for this service. Since silicone and BISCO materials are made of inert materials, IP does not expect that placing BISCO seal in contact over the silicone sealant

! material will result in any adverse interactions or degradation. For

, those systems already successfully leak tested, additional leak testing will not be required following BISCO seal installation. The remaining systems will be leak tested when required to support system operability needs.

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r U-600814 L30-87(01-23)-L 1A.120 For the instances where silicone sealant material was discovered inside the filter housings, this material will be removed.

2. Milestone Completion Schedule For the Engineered Safety Feature (ESF) systems involved (i.e.,

Control Room HVAC, "VC", and Standby Gas Treatment System, "VG") the conduits will be sealed prior to Initial Criticality to support CPS Technical Specification (TS) operability requirements. The "VG" system's ability to maintain secondary containment negative pressure and the "VC" system's ability to meet supply air / makeup air filter housing leakage requirenents have been verified during startup testing. These test results, in conjunction with reasonable assurance that the silicone sealant material will not degrade under tha environmental conditions which currently exist, support the conclusion that these ESF systems could be declared TS operable even in their current state.

For the non-ESF systems affected (see Attachment). IP will complete the required action plan prior to startup following the first regularly scheduled refueling outage. The basis for this decision is that the housings have been leak tested with the silicone sealant in place and have passed. Since there is reasonable assurance that silicone sealant will not degrade significantly during the first fuel cycle, and given the fact that these non-ESF systems perform no safety-related filtration functions, IP's proposed milestone

,, completion schedule should be acceptable to the Staff.

The referenced discussion with your Staff provided preliminary indication that the above action plan and schedule would be acceptable. IP understands that the Staff intends to provide the results of your review of this matter in Supplement #8 of the CPS Safety Evaluation Report (NUREG-0853).

, Should the Staff have any further questions regarding this issue, please contact me.

Sincerely yours, F. A. Spangenberg D

Manager - Licensing and Safety i

, TLR/bsa Attachment i~

cc: B. L. Siegel, NRC Clinton Licensing Project Manager NRC Resident Office Regional Administrator, Region III Office Illinois Department of Nuclear Safety Mr. J. Lee, NRC/NRR, BWPS 4

'e U-600814 L30-87 (01-23)-L 1A.120 ATTACHMENT r

ESF or System Tech. Spec. System Non-ESF Remarks / Corrective Action l Laboratory (VL) No Non-ESF -Silicone in lighting.

HVAC conduit of trains A and B.

Drywell Purge No Non-ESF Silicone in conduits of (VQ) trains A, B and C.

i Silicone observed on prefilter and demister l

j housing on train C was i removed. Silicone on-charcoal viewports for trains A, B, C.

Radwaste Building No Non-ESF Silicone in conduits of (VW) HVAC trains A and B.

Breathing Air No Non-ESF No silicone in conduits.

(RA) HVAC Silicone observed in Electric heater box.

Control Room (VC) ,

HVAC i

1. Supply Air Yes ESF Silicone in conduits but

! Filter not in interior of trains l

A and B.

7. Make-up Air Yes ESF Silicone in lighting and Filter Fire Protection conduits

! of trains A and B;

! silicone in charcoal view

! port of train A only.

Standby Gas Yes ESF Silicone in lighting and ,

Treatment (VG) Fire Protection conduits HVAC of trains A and B.

i l Machine Shop (VJ) No Non-ESF No silicone observed in f HVAC Machine shop. Silicone in lighting conduits of l

l Decontamination and weld i shop.

i l

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