ML20195H934
| ML20195H934 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 11/22/1988 |
| From: | Chrzanowski R COMMONWEALTH EDISON CO. |
| To: | Muller D Office of Nuclear Reactor Regulation |
| References | |
| RTR-REGGD-01.108, RTR-REGGD-01.155, RTR-REGGD-1.108, RTR-REGGD-1.155 5327K, NUDOCS 8812010121 | |
| Download: ML20195H934 (2) | |
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); One Fir.1 National Plan CNeago, ILnors Commonweedth Edloon d
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Address Reply to: PoNst Dox767 -
Chacaco,ILnos 60690 0767 l
o November 22, 1988 t
l Mr. Daniel R. Muller Nuclear Reactor Regulation U.S. Nuclear Regulatory Cowenission Mashington, DC 20555 Subject Byron Units 1 and 2 i
Interpretation of Emergency j
Diesel Generator Valid Demands L
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0 Dear Mr. Muller 4 l
1 I
Copenonwealth Edison is requesting an NRC staff position concstning j
the classification of Ermorgency Diesel Generator (EDG) valid demands.
In l
j accordance with Byron Station Operating Licenses NPT-37 an.d NPT-60. Appendix j
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A, Technical Specification 4.0.1.1.3, EDG testing frequency is determined based on the number of EDG failures during the previous twenty valid demands.
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Regulatory Guide 1.108 is currently used to determine the validity of these l
l EDG demands.
A clarification concerning the validity of certain EDO demands is i
j required to insure accurate compliance with specification 4.8.1.1.3.
j in June of 1983, Regulatory Guide 1.155 was issued to provide guidance concerning station blackout. Within Regulatory Guide 1.155, target 1
levels for EDG reliability are discussed. Section C, paragraph 1.1 references j
Section 2 of Nuclear Safety Analysis Center (NSAC) Report 108 titled "Reliability of Emergency Diesel Generators at U.S. Nuclear Power Plants" for j
calculations of EDG reliability. NSAC 108, Section 2, paragraph A1, suggests j
that EDG reliability is based en start reliability and load run reliability l
j where these factors are independently considened.
Specific guidelines for determining actual reliability are further described in Section 2 of NSAC 1
108.
Regulatory Guide 1.108, Section C.2 (3) suggests that a diesel demand may only be considered a valid demand, and subsequently used for testing f
interval determination, if the demand included a successful start. in11 owed by
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successful loading to at 1 cast 50% of rated load for a minimum of one hour.
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- D. Muller November 22, 1988 To be consistent with the philosophy of Regulatory Guide 1.155 in determining the EDG reliability for survelliance testing and to comply with Technical Specification 4.8.1.1.31 (i.e. consiegring successful starts independent from loading), Commonwealth Edison suggests that an EDO run be considered a valid demand and successful response if the run meets either one of the following criteria:
1 1)
The EDG run meets the criteria listed in Regulatory Guide 1.108, Section C.2.e(3), or (2) The EDG starts and achieves rated speed, voltage, and frequency, as a result of a valid demand, regardless of the length of DC operation, or the load applied, if any.
For example, a valid demand j
can be the result of any of the following 1
I a) a bonafide safety injection signal j
b) an actual icss of off-site power signal, c) a spurious safety injection sigsal, d) a safety injection signal dellberately induced as a result of a test, and e) a loss of off-site power signal deliberately induced through a test.
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Please direct any questions you may have regarding this matter, to l
this office.
i Very truly yours, jjlh I
gesd w
/
j R. A.jthrsanowski Huclear Licensing A&ninistrator l
l cc Byron RetAdent Inspector Braidwood Resident Inspector S.P. Sands - NRR, Project Manager J
E. Tomlinson - NRR Region III Office J
5327K 1
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