ML20214Q258

Summary of 861121 Meeting W/Util in Framingham,Ma Re Questions on Analysis of Wind & Tornado Events.Licensee Agreed to Provide Written Responses to Question within 30 Days.Addl Questions Raised & List of Attendees Encl

ML20214Q258
Person / Time
Site:	Yankee Rowe
Issue date:	11/25/1986
From:	Mckenna E Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 8612050061
Download: ML20214Q258 (5)

Text

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NOV 2 5 tggg Docket No.50-029 FACILITY: Yankee Nuclear Power Station LICENSEE: Yankee Atomic Electric Company

SUBJECT:

MEETING

SUMMARY

- NOVEMBER 21, 1986 On November 21, 1986, members of the NRC staff met with representatives of Yankee Atomic Electric Coinpany (YAEC), the licensee for the Yankee Nuclear Power Station, in Framingham, Massachusetts. The list of attendees is provided in Enclosure 1.

The purpose of the meeting was to resolve the last remaining questions on YAEC's analysis of wind and tornado events. Questions were sent to YAEC on November 3, 1986,; additional questions raised at the meeting are provided in Enclosure 2.

During the meeting, the staff reviewed the licensee's calculctions relating to the ventilation stack, and the licensee's assessment of dynamic effects, such as vortex shedding.

With respect to block wall allowables, the licensee noted that for the cost-benefit analyses, the design allowables were increased by a factor of 1.67 to obtain an ultimate capacity. The values specified in the criteria document were the design allowables.

One of the staff's major concerns with the licensee's assessment was the treatment of interior walls. In particular, the staff was concerned that failure of the west (exterior) wall of the diesel generator building could result in loss of more than one diesel generator since the interior walls between the diesels might be subjected to wind loads. The licensee committed to upgrade the capacity of the west wall to 134 mph. This will resolve the staff's concern.

The licensee agreed to provide written responses to the staff questions within 30 days.

Sincerely, s/

Eileen M. McKenna, Project Manager Project Directorate #1 Division of PWR Licensing-A

Enclosures:

a612050061 861125 ~

As Stated hDR ADOCK 05000029 PDR cc's: See Next Page Office:

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PD/ PAD #1 4j' .

Surname: EMcKenna/ g Glear Date: f 11/gz/86 11/ tJ/86

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Mr. George Paper.ic, Jr.

Yankee Atomic Electric Company Yankee Nuclear Power Station cc:

Fr. James E. Tribble, President Yankee Atomic Electric Company 1671 Kercester Road Framingham, Massachusetts 01701 Thomas Dignen, Esquire Eopes and Gray 225 Frar.-klin Street Bosttr. f'assachusetts 02110 Mr. f;..N. St. Laurent Plant Superintendent Yankee Atomic Electric Company Star Route Powe, Massachusetts 01367 Chairman Board of Selectmen Town of Rowe Rowe, Massachusetts 01367 Resident Inspector Yankee Nuclear Power Station c/o U.S. NEC Post Office Box 28 Monroe Bridge, Massachusetts 01350 J Regional Administrator, Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 Robert M. Halliscy, Director Radiation Control Program Massachusetts Department of Public Health 150 Tremont Street, 7th Floor Boston, Massachusetts 02111

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ENCLOSURE 1 NOVEMBER 21, 1986 MEETING NAME AFFILIATION Eileen.McKenna NRC/ PAD 1 Pei-Ying Chen NP.C/PWR-b/ISAPD Steve Triolo. FRC Bruce Holmgren YAEC George Harper YAEC Donald LeFrancois. YAEC George Papanic, Jr. YAEC James L. Staub YAEC Steve Follen 'YAEC e

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ENCLOSURE 2 QUESTIONS ON WIND AND TORNADO COST-BENEFIT STUDY

1. The qualitative statements regarding the limited impact of failing wall D11053 have merit but may not be sufficient tc resolve the staff's concern in this matter, e.g. that failure of 011053 could lead to failure of all three diesel generators.

2. The development of top event LE (see page 5 of 21 in 9-5-86 YAEC letter) needs further clarification. The staff notes that OERCMOV can be used to reduce the unavailability of the recirculation valves, but its position in the ecuation reduces the unavailability of the diesel generators as well. Please explain. As part of the response, elso clarify the time for operator action between reaching the point when recirculation should be established per the procedures and when it must be established to prevent pump damage.

3. On page 4 of 21'(Question 2 response) the statement is made, "The failure of the non-return valve platform is not an important contributor to failure as discussed below for Q 11." How does 011 (main steam / feed support structure) relate to the hRV platform?

4. With regard to exterior wall T1J2 (page 15 of 21),.what equipment important to safety is located outside the auxiliary boiler room that could be affected if interior walls are exposed to the wind load after T1J2 fails?

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Docket No.50-029

'NRC PDR Local PDR PAD #1 r/f PAD #1 s/f Glear EMcKenria 0GC-Bethesda Edordan BGrimes ACRS (10)

NRC Participants (cc: Licensee and Plant Service List)