ML20209D327

Forwards Equipment Qualification Branch Addl Comment on Preliminary Review of External Events Analyses Re Probabilistic Safety Assessment

ML20209D327
Person / Time
Site:	Seabrook
Issue date:	09/21/1984
From:	Brocoum S Office of Nuclear Reactor Regulation
To:	Thadani A Office of Nuclear Reactor Regulation
Shared Package
ML20209C800	List: ML20209C798 ML20209C897 ML20209D266 ML20209D278 ML20209D286 ML20209D327 ML20209D479 ML20209D512 ML20209D547 ML20209D870 ML20209E015 ML20209E274 ML20211C165 ML20211C259 ML20211C363 ML20211C389 ML20211C430 ML20211C484 ML20211C558 ML20211C632 ML20211C641 ML20211C679 ML20211C769 ML20211C792 ML20211C841 ML20211C904 ML20211C920 ML20211C942 ML20211D042 ML20211D068 ML20211D076 ML20211D092 ML20211D109 ML20211D129 ML20211D140 ML20211D169 ML20211D178 ML20211D191 ML20211D198 ML20211D208 ML20211D226
References
FOIA-87-6 NUDOCS 8410020092
Download: ML20209D327 (2)

Text

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'o, UNITED STATES y

g NUCLE AFLREGULATORY COMMISSION p

WASHINGTON. D. C. 20555 s.,.....J SEP 211984 i

MEMORANDUM FOR:

Ashok Thadani, Chief Reliability and Risk Assessment Branch Division of Safety Technology l

[JamesP. Knight,AssistantDirectorfor THRU:

Components & Structures Engineering

/

g/ ; -

Division of Engineering FROM:

Stephan Brocoum, Acting Chief Geosciences Branch Division of Engineering

SUBJECT:

PRELIMINARY REVIEW 0F THE EXTERNAL EVENTS ANALYSES IN THE SEABROOK STATION PROBABILISTIC SAFETY ASSESSMENT (PSA) - ADDITIONAL COMMENT l

Attached to this memorandum is an additional review coment to be l

transmitted to the Seabrook applicants.

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Stepha,1 Brocoum, Acting Chief Geosciences Branch Division of Engineering

Enclosure:

As stated cc:

R. Vollmer J. Knight s

Fo T M - 8 7-oo 4 F. Rowsome S. Brocoum L. Reiter bhf R. Frahm T. Sullivan S. Davis P. Sobel A. Masciantonio ipz4+92m xk

Equipment Qualification Branch Preliminary Coment on Seabrook PSA 5.

With respect to relay chatter, there are those relay trips which may require resetting at local panels, resulting in failure to reset if the operator is presented with a scenario for which he has not been trained or no procedure is available for guidance. Failure to reset is equivalent to relay failure. Please provide additional information on the analysis of relay chatter and address the impact on the various systems. Lack of operator action to reset under conditions of stress leading to relay failure should be considered.

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