ML19345B807
| ML19345B807 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 11/26/1980 |
| From: | Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8012020547 | |
| Download: ML19345B807 (2) | |
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D PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET i
P.O. BOX 8699 i
PHILADELPHI A. PA.
'" 91 smat.os t DAMMOFF
. =::=
November 26, 1980
!! r. Robert U.
Reid, Chief Operating Reactors Branch #4 Division of Licensing Nuclear Regulatory Conmission Washington, DC 20555 Dear !f r.
Reid:
In our letter of October 5,
1978 we proposed modifications to the Reactor Protection System (RPS) power supply to protect the RPS from undetected single failures and from a postulated sequence of events initiated by an earthquake.
Your letter of September 24, 1980 requested a schedule for completion of our modifications and a schedule for submission of design information and Technical Specifications.
As per our previous submittal, we propose installing Class lE detection and isolating devices between the output of l
the RPS motor generated (!!G ) sets and the RPS load.
Design information for these devices and our proposed modification is attached.
j Procurement of the detection and isolating devices needed for this modification is proceeding at this tine.
Peach Bottom 2 Unit RPS power supply nodifications will be made during the refueling outage scheduled for January, 1982.
The next refueling outage for Unit 3 begins in March, 1981, however, your letter indicates that a subsequent refueling outage is acceptable if the first scheduled outage is within six months of your letter.
We will still attempt to make this modification to Unit 3 during the Spring, 1981 outage contingent on procurement of the necessary equipment.
If this equipment is not available in time i
for the outage, the modificaticos will be made no later than the Fall, 1982 refueling outage.
Technical Specifications which incorporate our proposed RPS power supply design will be submitted by July 31, 1981.
/f
.5 Very truly yours, I
1 f-Attachment 8 012 020 gy7
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1 PEAC!! BOTTOM ATOMIC-POWER STATION
-UNITS 2'AND 3 REACTOR PROTECiIO$ SYSTCM P01/E R SUPPLY MODIFICiTIONS A Class 1E circuit breaker panel will be installed on the output of each RPS MG set (2 per Unit).
Each panel will be divided-by a steel ~ barrier into two separate compartments.
Each compartment will. house an overvoltage. sensing relay,.an undervoltage. sensing relay, an underfrequency sensing relay, a two pole, magnetic trip, shunt trip circuit breaker, a control 4
. power monitoring relay and a time delay. trip relay.
The devices that we anticipate using are:
Undervoltage GE NGV13 108 VAC Setpoint Overvoltage GE NGV23 132 VAC Setpoint Underfrequency GE
.SFF31A 57 11: Setpoint i
Circuit Breaker GE TJJ400A Control Power Agastat EGP Time Delay Agastat ETR 10 Secs. Setpoint 4
Each compartment will be provided with a s,eparate 125V DC i
circuit for use as control power.
The'contrel power'will be E
continuously monitored-and alarmed by the EGP relay (A loss of DC will prevent the tripping of one of the circuit breakers).
1 When one of the relays operate, the timing sequence on the ETR relay will begin.
If the voltage or frequency variation persists for more than the setpoint of the ETR, the circuit 1
breaker will be tripped.
Since both sets of relays per panel will be conitoring the same conditions, both series circuit breakers will be tripped, although independently.
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The panels will be designated Class lE and will be qualified for their operating environment per IEEE 323-1974 and IEEE 344-i 1975.
They will be purchaced as qualified devices and will have the. documentation as required by the above IEEE standards.
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