ML19343B300

Responds to Alleged Potential Problems Re Fire Barrier Penetration Seals Installed by Chemtrol Corp.Investigation Underway to Assess Seal Acceptability

ML19343B300
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	12/19/1980
From:	Conway W VERMONT YANKEE NUCLEAR POWER CORP.
To:	Ippolito T Office of Nuclear Reactor Regulation
References
WVY-80-172, NUDOCS 8012230192
Download: ML19343B300 (3)

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ENGINEERING OFFICE t.o O

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December 19, 1980 t

i United States Nuclear Regulatory Commission k*ashington, D.C. 20555

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Attention:

Office of Nuclear Reactor Regulation i

Thomas A. Ippolito, Chief Operating Reactors Branch #2 L

Division of Licensing

References:

(a) License No. DPR-28 (Docket No. 50-271)

(b) USNRC Letter dated January 13, 1978, Amendment 43 to Facility Operating License.

Subject:

Fire Berrier Penetration Seals 1

This letter is intended to respond to-the.tvo letters you re-

.cently received from the Chemtrol Corporation. These letters. allege d

a potential problem with the~ fire barrier penetration seals that they

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installed at Vermont Yankee. Chemtrol raised the concern that our i

seals might be rated for only one'and one half hours instead of the o

required three hours. An investigation is underway to assess the ac-ceptability of our seals. The major areas of investigation and cur--

rent status of these investigations are as follows:

1 A.

Penetration Inspection

.As noted in the second Chemtrol letter, approximately i

27 percent of the seals at Vermont Yankee are involved.

Of that amount, approximately 80 percent are in the wall separating the Reactor Building from the Switchgear Room and Cable Spreading Room.in the Control Building. All areas containingLthe potentially defective l seals have been-

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j inspected with particular attention paid to.the areas with the largest number offseals. This' inspection was done by an NRC Inspection and Enforcement Inspector, the Vermont-Yankee Resident Inspector,.and the Yankee Nucient Services.

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-Division fire proteccion engineer.- The. assessment of-the i

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t VERMONT YANKEE NUCLEAR POWER CORPORATION U.S. States Nuclear Regulatory Commission December 19, 1980 Page 2 investigation was -hat no immediate action was required other than a close cu..ral of transient fire loading in those areas containing the largest amount of potential problem seals, the Switchgear Room, Cable Spreading Room, and the major Reactor Building Penetration Area.

B.

Review of Existing Test Data Chemtrol's test methods and esta are being compared to those of GE (manufacturer of the foam used ia our seals) and other companies.

Cheatrol's test assembly does not appear to be typical of the Vermont Yankee penetrations, particularly in the ratio of the amount of scalant material to the amount of tray, conduit and cable in the penetratien.

A preliminary review of the different foam man-ufacturers' tests leads us to believe that most of our penetration seals were installed in a more conservative

=anner than those tested by the foam manufacturers with apparently acceptable results.

C.

Proof Testing of Vermont Yankee Seals 1.

Cheatrol is analyzing actual component samples of the alleged defective material used in the seal assembly test that did not pass the three,aur rating.

2.

Vermont Yankee will independently test a sample of the material from Item 1.

3.

We will test a sample taken from one of the potential problem seals installed at Vermont Yankee.

A.

GE is checking QA records on material used at rmont Yankee and for the Chemtrol Test.

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Tests done by other companies using the same material are being reviewed.

Vermont Yankee intends to maintain its commitment to provide three-hour rated fire barrier penetration seals.

Based on the pre-liminary reviews we have done in Items A and B above, we do not feel, at this time, that there is a confirmed deficiency with our seals.

The areas of greatest concern, the cable penetration areas between the Reactor Building Cable Spreading Room and Switchgear Room area, are provided with fire detection.and automatic suppression systems.

The J

s VERMONT YANKEC NUCLCAR POWCH CORPORATION U.S.

States Nuclear Regulatory Commission Decenber 19, 1980 Page 3 l

Switchgear and Cable Spreading Rooms have an automatic CO2 system with the Cable Spreading Room also having second reserve shot capacity.

The cable penetration area in the Reactor Building has a set stand-pipe sprinkler system for the floor below the penetrations to protect them from a fire originating in that area.

Should the continued investigations of Itens A and 3 or the analyses of Itc= U indicate the possibility of a deficiency with our seals we will send additional samples of our seals for chemical anaysisis and/or reseal the defective penetrations with an ac-ceptably tested caterial.

The schedule for completing our penetration evaluation is not firn at this noment. We desire to have reviews and tests of samples completed by the middle of January.

If additional tests of Vermont Yankee's penetrations are called for, they would be completed by the end of March, 1981.

We trust the above information is acceptable to you.

If you have further concerns or cuertions, please contact us.

Very truly yours, VERMONT YANKEE NUCl. EAR POWER CORPORATION W.F.

onway Vice President and Manager of Operations WFC/j h

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