ML17037B661

Letter Regarding a Program to Better Understand Recent Data Which Indicates That Core Spray Distribution, Under Accident Conditions, Could Be Negatively Affected by the Presence of a Steam Environment, Pressure, and Updraft ..

ML17037B661
Person / Time
Site:	Nine Mile Point
Issue date:	12/10/1976
From:	Lear G Office of Nuclear Reactor Regulation
To:	Rhode G Niagara Mohawk Power Corp
References
Download: ML17037B661 (4)

Text

~or OEO g P 19' Oocket No. 50-220 Niagara ttohawk Power Corporation ATTh: Hr. Gerald K. Rhode Yice President - Engineering 300 Erie Boulevard West Syracuse, New York 13202 Gentlemen:

RE: tlIt<E t!ILE POINT NUCLEAR STATION UNIT., t~0. 1 The Regulatory Staff is currently pursuihg with the General Electric Company a program to better understand recent data which indicates that Core Spray distribution, under accident conditions, could be hegatively affected by ttie presence of a steam environment, pressure differential across the spray area and updraft. The presence of steam can narrow (contract) the cone solid angle for certain type nozzles; thus, the spray flow in certain bundles may be lower than previously assumed. This phenomenon could occur in both single nozzles and ring sparger systems. Available data are summar ized in the enclosed t!ecting tlinutes.

Me ar e concerned that this effect has not been considered in the spray coefficients used as input to the non-Jet pump ECCS analysis for the Nine I'1! le Point Nuclear Sation Unit tfo. 1 'Plant. In light of the recent data that has become available to the General Electric Company regarding effects on spray distribution due to steam environment, pressure, and up-

, draft, and considering the minimum spray flow present in General Electric Company Topical Report APEO-4927 and APED-4928 tests (or any other test

,data you choose to reference in support of your, assumed spray cooling coefficients), we request that you provide justification for your assumed spray cooling coefficients. Further, we request that you inform us, within 30 days from the receipt of this letter, of'our schedule for a complete response, including description of any tests you might propose to obtain data applicable to your plant.

OPPICC~

9 VIIHA M C W OATC ~

POTIO hEC.318 (ROT. 9-H) hZCM 0240 Q V, 9, OOVCIIHMCNTPAINTINO OPPICCI ION 529 I49

17 E.

V I

F lt

If you have any questions or wish to discuss this matter, please contact us ~

Sincerely, George Lear, Chief Operating Reactors Branch 03 Division of Operating Reactors

Enclosure:

Meeting Minutes cc: Arvin E. Upton, Esquire LeBoeuf, Lamb, Leiby 8 MacRae 1757 H Street, H. M.

Mashington, D. C. 20036 Z. Roisman, Esquire 'nthony Roisman, Kessler and Cashdan 1025 15th Street, H. M.

5th Floor t,"ashington, 0. C. 20005 Hr. Eugene G. Saloga, Applicant Coordinator Nine t1ile Point Energy Information Center P. 0. Box 81 Lycoming, Hew York 13093 DISTR I BUT IOH:

Docket OELD NRC PDR'I8IE (3)

, Local PDR DEisenhut ORBS'3 Rdg TBAbernathy 4QSi8@r JRBuchanan TJCarter ACRS (16)

GLear File CPar rish DVerrelli 8KNHXSNowicki

.......0889.3~..... .........O.RBN OAPICC3D'VANAMCW OVer rel 1 i: ac SNowjcki ...6.Learn..~

bATC+ 12/ It /76 12/ / 6 1.27...,....~..0 ....l.7..6,.

Form hEC 318 (RCT. 9.33) hKCM 0240 4 U, 4, 5OVCANMCNT ARINTINO OAAICCI ID74 424 154

s J

l'

~ 1 p

F I