ML19207C089
| ML19207C089 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 05/09/1979 |
| From: | Capodanno G GENERAL PUBLIC UTILITIES CORP. |
| To: | Cronenberger D GENERAL PUBLIC UTILITIES CORP. |
| References | |
| TSG-163, NUDOCS 7909060428 | |
| Download: ML19207C089 (6) | |
Text
Inter-Office Memorandum-G fll.4LWN /-
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Ca:e May 9, 1979 r yr s._,
Subjoct Criteria for Modifications to Class IE Electrical System To MR. D. K. CRONEBERGER Loca on TMI The attached subject document is forwarded for review and comment. The proposed changes to the Class lE electrical system are necessary to ensure safe operation of the plant in the present and future modes.
The autere'c actuation of some of the previously engineered safety feature systems 1.'
1d be detrimental to the plant safety. However, so that the backup capability of systems are not totally defeated, the Class lE power to the equipment should be retained.
GPU is currently investigating the details of defeating the automatic actuation interlocks.
GPUSC will develop the necessary ECM(s) to implement the herein described recomnendatIons.
f.k.-in u-G. R. CAPODANNO GRC:ms Attachment cc:
D. G. Slear R.
F. Wilson G. Lainis (3) (SRC)
W. R. Cobean (B&R)
L. Harding T. G. Broughton G. Troffer (Met-Ed)
R. Warren (6)(Met-Ed)
J. McMillan (B&W)
T. M. Crimmins L. Lanese G. Kunder Modification File Stat;dt/ File SASO2'5 7909060 GPU Service Corporahon is a subsd.ary of General Pubhc Utit:c - Corporation
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CRITERIA FOR MODIFICATIONS TO CLASS lE ELECTRICAL SYSTEM (REV 0)
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CRITERIA FOR MODIFICATIONS TO CLASS lE ELECTRICAL SYSTEM l.G 3 COPE This document defines modificctions to the Clcss lE electrical system needed to ensure safe operation of the plant in the present. and planned operating modes.
2.0 REQUIREMENTS 2.1 It is essential that the integrity of the Cla ss lE electrical system be maintained since portiona of the originally installed emergency core cooling systems and reactor containment systems are still required.
2.2 Major modifications to the Class IE electrical system are unacceptable, and minor modifications are to be minimized, consistent with requirements for plant safety.
This will minimize the chances for disturbance of the system, for introducing wiring errors, and for unexpected operational consequences.
2.3 In the present and planned operating modes of the plant, the unplanned operation of certain systems would result in undesirable transients.
Specifically, the unplanned operation of the decay heat remoial system, the reactor building spray system, the high pressure injection system, or emergency feedwater is highly undesirable. However, continued automatic operation of the reactor building air cooling fans, reactor building emergency cooling booster pumps, nuclear services river water systems, control building HVAC and associated systems, instrument air compressors, and Class 1E DC and vital AC systems is desirable to minimize operator actions required in the event of a loss of off-site power.
2.4 The simplist and, therefore, the most trouble-free method of achieving the desired defeat of the automatic activation of large (pump) loads is to place the control switches in the pull-to-lock position and tag them in accordance with the plant's existing tag-out procedures.
The specific equipment for which this shall be done is listed in Attachment A.
2.5 Certain valves, for which switches with the pull-to-lock facility is not available, will require control circuit modifications to disable automatic open/close control signals.
A tentati/e list of these valves is provided in Attachment B.
This list should be reviewed and then appropriate circuit modifications developed.
2.6 Concern has been expressed about the inadvertent opening of containment isolation valves.
At present, all containment isolation valves are tagged in accordance with the plant's existing tag-out procedures.
Based on the philosophy of manual control for systems, this level of control is considered adequate.
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Criteria for !!odification to Class lE Electrical System Page 2 2.7 Concern has also been expressed about the consequences of inadvertent generation of an Engineered Safety Features (ESF) signal. With those systems whose inadvertent operation could be detrimental to plant safety locked out in acccrdance with paragraphs 2.4 and 2.5 above, an inadvertent ESF signal will not affect plant safety.
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e ATTACHMENT A CLASS 1E MOTOR CONTROLS TO BE PLACED IN " PULL-TO-LOCK" POSITION Decay Heat Removal Pump DH-P-1A DH-P-1B Emergency Feedwater Pump EF-P-2A EF-P-2B Reactor Coolant Makeup Pump MU-P-1A
- MU-P-1B
- MU-P-1C *
- Containment Building Spray Pump BS-P-1A BS-P-1B 1orBnormallyoperatingformakeup/letdevnandseal injection. The pump not operating should have switch in
" pull to lock."
Automatic actuation of high pressure injection by ESF (Safety Injection) shall be disabled.
MU-P-lC will not be used.for normal makeup. Motor controls should be placed in " pull to lock."
If it is decided to provide RC makeup and seal injection using MU-P-lC, then the automatic starting of this pump by ESF signal (Safety Injection) shall be disabled.
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TITACle!ENT B CLASS lE VALVE CONTROLS TO BE INTERLOCKED PER REQUIRED STATUS SYST EM DESIGNATION STATUS Emergency Feedwater System EF-V4A Valves to remain as is in EF-V4B the event of ESF signal.
EF-V12A EF-V12B EF-V33A EF-V33B Containment Building Spray BS-VlA Valves to remain shut in BS-V1B the event of ESF signal.
High Pressure Injection MU-V16A )
All six valves are to remain MU-V16B )
as is in the event of ESF MU-V16C )
signal.
MU-V16D )
MU-V36
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MU-V37
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Decay Heat Removal DH-V2 Isolation valves to be DH-V3 normally closed at all times.
DH-V4A Automatic actuation to be DH-V4B disabled.
DH-VSA DH-V5B DH-V8A DH-V8B DH-V102A DH-V102B 4
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