ML13317A519

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Clarifies Response to Item 6 of Re Review of Emergency Operating Procedures to Verify Appropriate Isolation of Letdown Flow,Per NUREG-0737,Item II.B.2, Post-Accident Shielding. Warnings Posted in Control Room
ML13317A519
Person / Time
Site: San Onofre 
Issue date: 02/22/1983
From: Baskin K
Southern California Edison Co
To: Crutchfield D
Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TAC-44128, TASK-2.B.2, TASK-TM NUDOCS 8303070018
Download: ML13317A519 (2)


Text

Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER OF NUCLEAR ENGINEERING, February 22, 1983 (213) 572-1401 SAFETY, AND LICENSING Director, Office of Nuclear Reactor Regulation Attention:

Mr. D. M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C.

20555 Gentlemen:

Subject:

Docket No. 50-206 NUREG-0737, Item II.B.2 - Post-Accident Shielding Post-Implementation Review San Onofre Nuclear Generating Station Unit 1

Reference:

Letter, K. P. Baskin, SCE, to D. M. Crutchfield, NRC, NUREG-0737, Item II.B.2 - Post-Accident Shielding, Post-Implementation Review, January 19, 1983 The referenced letter provided you with the necessary information to complete your post-implementation review of the subject post-TMI requirement.

Our response to Item 6 of that letter informed you of our intention to review our emergency operating procedures to verify appropriate isolation of letdown flow. Recent telephone conversations with members of the Region V Staff have indicated a need for additional clarification as to the method that will be used to isolate letdown flow and verify that operators and emergency response personnel are aware of the radiological hazard of letdown flow reinitiation.

It is the purpose of this correspondence to provide you with the necessary clarification to enable the completion of your SER on this TMI requirement.

The review of our Emergency Operating Instructions (EOIs) for San Onofre Unit 1 show that the EOIs instruct the operator to isolate letdown on a reactor trip or safety injection where appropriate. The procedure in which letdown is isolated is a Functional Restoration Guideline (FRG), "Response to High Containment Radiation Level," which alerts operators and the emergency response personnel in the TSC to radiological hazards outside of containment.

This FRG is entered via the Containment Critical Safety Function Status Tree, which is continuously monitored during the accident from the time the operator transitions from "Reactor Trip" or "Safety Injection."

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Mr. D.

February 22, 1983 The requirement in the EOIs to consider the hazard of letdown flow after an accident is in the form of a CAUTION to the operators and the TSC emergency response personnel monitoring the accident via the EOIs.

This action will ensure that there is adequate attention given by responsible persons to isolation of letdown flow and any reinitiation of letdown would be considered by more persons than the shift operations staff in the control room.

It should also be noted that the posted warnings discussed in our response to Item 3 of the referenced letter were posted as of Februry 10, 1983. These warnings in the northwest corner of the control room area (in back of the vertical boards) will provide adequate warning to operations personnel.

If you have any questions regarding the above discussed clarification, please let me know.

Very truly yours, cc:

R. H. Engelken, Regional Administrator NRC Region V (3)

M. L. Padovan, NRC Region V (1)