ML20093K852
| ML20093K852 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 07/25/1984 |
| From: | Hobbs S MISSISSIPPI POWER & LIGHT CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| AECM-840377, NUDOCS 8407310214 | |
| Download: ML20093K852 (2) | |
Text
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j MISSISSIPPI POWER & LIGHT COMPANY n
Helping Build Mississippi M
P. O. B O X 184 0, J A C K S O N, MIS SIS SIP PI 3 9 2 05 July 25,1984 NUCLEAR LICENSING & $AFETY DEPARTMENT Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention:
Mr. Harold R. Denton, Director
Dear Mr. Denton:
SUBJECT:
Grand Gulf Nuclear Station Units I and 2 Docket Nos. 50-416 and 50-417 License No. NPF-13 File 0260/L-860.0 EPA Surveillance AECM-840377 Mississippi Power & Light Company (MP&L) is providing this letter as an addendum to the additional information supplied to your staff in a letter dated July 13, 1984 to support Technical Specification Problem Sheet (TSPS) 181. The additional information relates to a proposed change to the Grand Gulf Nuclear Station (GGNS) Technical Specifications transmitted by a letter from Mr. J. P. McGaughy to Mr. Harold R. Denton dated June 21, 1984 concerning the channel functional test frequency for the reactor protection system electric power monitoring assemblies.
The Electrical Protective Assemblies (EPA's) at GGNS consist of Class IE Seismic Category I circuitry and assemblies and are used to separate the Reactor Protection System (RPS) bcses from the non-essential, non-Seismic Motor Generator Sets. The EPA's also provide isolation between the Class IE Alternate Supply and the non-IE RPS power supply system in an accident.
The undervoltage, overvoltage, and under frequency instrumentation associated with EPA's provide additional assurance that the RPS components will be protected from a potentially degraded power supply. The RPS is a fail safe system in that failure (loss of voltage) results in protective feature actuation (SC" AM. solenoid operation).
Increasing the time interval between the EPA choanel functional test will not degrade the Reactor Protection System since the RPS function is not associated with the EPA breaker opening capability. Sufficient redundancy (two EPA breakers in series for each power supply) is provided such that the increase of surveillance frequency will not affect the other EPA functions.
Please contact this office if additional information ir required.
Yours truly, 8407310214 840725 4
DR ADOCK 05000 P
S. H. Hobbs Manager, Nuclear Safety & Compliance SHH/ sad cc:
(See Next Page)
Member Middle South Utilities System I
AECM-84/0377 Paga 2 MIZISSIPPI POWER. & LICHT COMPANY cc:
Mr. J. B. Richard (w/a)
Mr. R. B. McGehee (w/o)
Mr. T. B. Connor (w/a)
' Mr. G. B. Taylor (w/o)
Mr. Richard C. DeYoung, Director (w/a)
Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555
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