ML20003F963

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Requests Opportunity to Review AR Nuclear One 2 start-up Rept & Software Change Procedures to Determine Whether Sys as Changed & Procedures Which Cover Future Chages Insure That Facility Operated in Safe Manner
ML20003F963
Person / Time
Site: Arkansas Nuclear, San Onofre  Southern California Edison icon.png
Issue date: 03/03/1981
From: Lipinski W
ARGONNE NATIONAL LABORATORY
To: Kerr W
Advisory Committee on Reactor Safeguards
References
ACRS-CT-1324, NUDOCS 8104270193
Download: ML20003F963 (1)


Text

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g jyy ARCONNE NATIONAL LABORATORY 9700 South CAss Avu, ARCpt<. Ilnoes 60439 TEkphOrt 312/W2-4639 March 3, 1981 Dr. William Kerr Advisory Comittee on Reactor Safeguards U. S. Nuclear Regulatory Comission Washington, DC 20555

Dear Dr. Kerr:

Subject:

Review of Arkansas Nuclear One Unit 2 Experience with Core Protection Calculators as Related to San Onofre Unit 2 and 3 Operations The presentations made by Arkansas Power and Light at the February 24, 1981 meeting of the ACRS Electrical Systems Subcomittee on the operational experi-ence with the core protection calculators at ANO-2 were enlightening. As stated at the subcomittee meeting, software changes were made to improve the perform-ance of the CPCs. Not all of the changes were in the safe direction, i.e., (1) a software change was made in the rod position input circuit to reject a spurious open wire condition, and (2) the time constant of a lead-lag network algorithm was reduced because of noise imposed on the measured signal.

My current concern is with the software change procedure. What changes can the licensee make without requiring NRC review?

The original Combustion Engineering design of the CPCs was reviewed in consider-able detail before it became operational at ANO-2. I would like an opportunity to review the ANO-2 start-up report and software change procedures to determine whether the system as changed and the procedures which cover future changes insure that ANO-2 is operated in a safe manner.

San Onofre Units 2 and 3 will utilize CPCs and the software improvements imple-mented at ANO-2. The NRC staff review of the application of the CPCs at San Onofre Units 2 and 3 is still in progress and a staff report will be issued covering their review. It is recomended that the ACRS Electrical Systems Sub-comittee maintain cognizance of the work of the NRC staff in this review.

Sincerely, I

kN Walter C. Lipinski, Ph.D.

Senior Electrical Engineer Reactor Analysis and Safety Division WCL/at cc: R. Savio, ACRS l 8104270193 nc(kmy clOcq Aacan Uwasias Assce t