ML17053D105

Informs of Potential Reportable Condition in Hydrodynamic Loads in Piping & Supports of Control Rod Driveline Sys Causing Calculated Hydrodynamic Loads to Be Insufficiently Accurate.Requests Plan for Reinforcing Affected Component

ML17053D105
Person / Time
Site:	Nine Mile Point
Issue date:	04/05/1982
From:	Schwencer A Office of Nuclear Reactor Regulation
To:	Rhode G NIAGARA MOHAWK POWER CORP.
References
NUDOCS 8204190210
Download: ML17053D105 (6)

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50Q10 g g."QQ F~~>AINT ELQ$Q I0 fi4XJH Q!VBL'K8 vie I/e were recently informed by a vendor of control rod drive (CRD) syst of a potential reportable condition applicable to boiling water-reactor (Enclosure 1).

Specifically, this vendor indicates that its analysis of the hydrodynamic loads in the piping and on the supports of a particular CRD system for a "worst case" condition resulted in structural loads which were larger than some of the previous design loads For this system.

These larger loads result from a rapid actuation of tHe CRD.

The conditions assumed by this vendor for its "worst case" calculation of the hydrodynamic loads were:

( 1) a design basis opening time of 20 milliseconds for the inlet line scram valve; and (2 ) a scram during the start-up phase of the plant with no pressure in the reactor vessel.

The vendor also stated that its modeling of the CRD system may not be appro-priate which could cause the calculated hydrodynamic loads to be insuf-ficiently accurate.

Our concern in this matter is that the hydrodynamic loads in the CRD system for your facility may not have been properly evaluated.

Accordingly, we request that you provide the following information for your facility when you submit your application for an operating license:

1.

The design basis opening time for the inlet line scram valve.

2.

An evaluation'of the hydrodynamic loads in your CRD system resulting from actuation of the inlet line scram valve using the design basis opening time specified in Item 1.

DISTRIBUTION:

Docket File RHartfield, I)PA LB¹2 File DEisenhut/RPurple bcc:

PRC RTedesco NSIC ASchwencer NRC PDR DLynch Local PDR EHylton ACRS (16)

Bordenick, OELD OI 81E Region I Resident Inspector

'Hanauer RNattson

Dear tIr. Rhode:

HThompson RYol lmer IWp~ 09 ~98~~

Sub]ect:

"Fast Scram" Hydrodynamic Loads on Control Rod Drive Syst a 8204i 902i0 820405 PDR ADOCK 05000410 A

PDR USQPO: 1981~9 990 OFF1CEP SURNAME$

DATE II, NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY

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2 3.

A description of the conditions and configurations of the plant

<<hich Oresult in the maximum hydrodynamic loads in the CRD system.

4.

A statement regarding the appropriateness of the mathematical model used to calculate the hydrodynamic loads in the CRD system resulting from a scram.

5.

A comparison of the hydrodynamic loads evaluated in Item 2 with the present design basis loads for the CRD system.

In the event that the hydrodynamic loads calculated for your facility exceed the present design basis structural loads for the CRO system, indicate in your FSAR which components are affected.

Describe your plan for structurally reinforcing the affected components.

If you have any questions on this matter, please contact the Proiect Manager, M. D. Lynch, at (301 ) 492-9793.

Sincerely,

Enclosure:

As stated cc:

See next page 00 00 A. Schwencer, Chief Licensing Branch f'o.

2 Division-b f-,Licensi.ng LB

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Mr. Gerald K. Rhode Vice President, System Project Management Niagara Mohawk Power. Corporation 300 Erie Boulevard West

Syracuse, New York 13202 cc:

- Leonard M. Trosten, Esquire

LeBoeuf, Lamb, Leiby 5 MacRae 1333 New Hampshire Avenue, N.

W.

Washington, D. C. 20036 Mr,. Richard Goldsmith Syracuse University College of Law E.'I. White Hall Campus

Syracuse, New York 13210 T; K. DeBoer, Director Technological Development Programs-New York S'tate Energy Office Agency Building 2 Empire State Plaza

Albany, New York 12223 Ezra I. Bialik Assistant Attorney General Environmental Protection Bureau New York. State Department of Law 2 World Trade Center New York, New York 10047 Resident Inspector Nine Mile Point Nuclear Power Station P. 0.

Box 126

Lycoming, New York 13093 Carl D. Hobelman, Esquire

LeBoeuf, Lamb, Leiby 8 MacRae 1333 New Hampshire

Avenue, N.

W.

Washington, D;C.

20036

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