ML20073A094

Forwards Response to SER Open Item 3 Re Plant Protection Sys Monitor Mods

ML20073A094
Person / Time
Site:	Clinch River
Issue date:	04/08/1983
From:	Longenecker J ENERGY, DEPT. OF, CLINCH RIVER BREEDER REACTOR PLANT
To:	Grace J Office of Nuclear Reactor Regulation
References
HQ:S:83:244, NUDOCS 8304110657
Download: ML20073A094 (2)

Text

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Department of Energy Washington, D.C. 20545 Docket No. 50-537 HQ:S:83:244 ApR 0 81933 Dr. J. Nelson Grace, Director CRBR Program Office Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Dr. Grace:

RESPONSE TO SAFETY EVALUATION REPORT (SER) OPEN ITEM NO. 3 - PLANT PROTECTION SYSTEM (PPS) MONITOR Enclosed are actions that the Clinch River Breeder Reactor Plant project will take to modify the design of the PPS monitor. These actions are in response to questions raised in discussion with the Nuclear Regulatory Commission staff regarding the independence and testability cf the PPS monitor. The enclosed information should enable the staff to view this as a confirmatory item and resolve Open Item No. 3 of SER Section 1.6.

Any questions regarding the enclosed inismation may be addressed to Mr. R. Rosecky (FTS 626-6355) of the Praaeet Office Oak Ridge staff.

Sincerely, J n R. Longene r Acting Director, Office of Breeder Demonstration Projects Office of Nuclear Energy Enclosure cc: Service List Standard Distribution Licensing Distribution Do0\

204110657 830408

[DRADOCK 05000537 PDR

CRBRP Actions Taken to Resolve the Chapter 7 Open Issue on PPS Monitor This enclosure transmits actions that the CRBR Project will '

take as a result of discussions with J. Mauch (NRC) on March 23, 1983, concerning the design of the PPS Monitor.

1. The design of the PPS logic test system will be modified to provide two independent Monitors

• such that failures in one Monitor will not propagate to the other Monitor.

The Monitors will be used to check the test results of each other.

2. Self-test features will be provided for each Monitor.

3. The automatic test of the PPS logic will be considered a safety related function and.will be performed by class lE devices. Thus, the PPS Monitors will be Class lE.

4. Each Monitor will be independent from other Monitors.

If isolation devices are required they will be qualified to the criteria in CRBRP SER Section 7.2-2-2.

5. Failure Modes and Effects Analyses will be performed on the PPS logic test system and in particular on the PPS Monitors. The design of the PPS logic test system will be modified to prevent any common mode failures identified in the FMEAs.

6. The PSAR will be updated to reflect the changes identified in this letter.

• Monitor is an automatic test device which tests the PPS logic by monitoring the Primary PPS logic as test pulses are inserted into the Primary PPS. Monitor also triggers the initiation of the test pulses.

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