Rk. Das et al., COMMERCIAL GRADE ITEM (CGI) DEDICATION OF MDR RELAYS FOR NUCLEAR SAFETY-RELATED APPLICATIONS, IEEE transactions on nuclear science, 41(4), 1994, pp. 1408-1416
MDR relays manufactured by Potter & Brumfield (P&B) have been used in
various safety related applications in commercial nuclear power plants
. These include emergency safety features (ESF) actuation systems, eme
rgency core cooling systems (ECCS) actuation, and reactor protection s
ystems. The MDR relays manufactured prior to May 1990 showed signs of
generic failure due to corrosion and outgassing of coil varnish. P&B h
as made design changes to correct these problems in relays manufacture
d after May 1990. However, P&B does not manufacture the relays under a
ny 10CFR50 Appendix B quality assurance (QA) program. They manufacture
the relays under their commercial QA program and supply these as comm
ercial grade items. This necessitates CGI Dedication of these relays f
or use in nuclear-safety-related applications. This paper presents a C
GI dedication program that has been used to dedicate the MDR relays ma
nufactured after May 1990. The program is in compliance with current N
uclear Regulatory Commission (NRC) and Electric Power Research Institu
te (EPRI) guidelines and applicable industry standards; it specifies t
he critical characteristics of the relays, provides the tests and anal
ysis required to verify the critical characteristics, the acceptance c
riteria for the test results, performs source verification to qualify
P&B for its control of the critical characteristics, and provides docu
mentation. The program provides reasonable assurance that the new MDR
relays will perform their intended safety functions.