ML20125D419
| ML20125D419 | |
| Person / Time | |
|---|---|
| Issue date: | 10/14/1976 |
| From: | Kirkwood R Office of Nuclear Reactor Regulation |
| To: | Novak T Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20125D401 | List: |
| References | |
| REF-GTECI-A-26, REF-GTECI-RV, TASK-A-26, TASK-OR NUDOCS 8001140289 | |
| Download: ML20125D419 (2) | |
Text
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MEMORANDUM FOR: Thomas M. Novak, Chief, Reactor Systems Branch, DSS ,
FROM: Robert Kirkwood, Plant Systems, DSS THRU: R. L. Tedesco, Assistant Director for Plant Systems, DSS
SUBJECT:
PROPOSED RSB TECHNICAL POSITION ON REACTOR COOLANT SYSTEM OVERPRESSURE PROTECTION Your memorandum of September 7,1976, requested comments to aid in formulating the detailed requirements for a proposed Reactor Systems Branch Technical Position on Reactor Coolant System Overpressure Pro-tection. This response is limited to the seismic and quality group classifications of overpressure protection components of systems
. modified to prevent overpressurization transients.
There are three proposed system modifications or combinations thereof to prevent overpressurization transients which are currently under consider-ation. These are: (1) dual set points on existing relief valves, (2) safety valve (s) which are blocked off during power operation by two valves, and (3) relief valves which are connected to other auxiliary systems. In each of these three cases, components should be designed to jiej,sgjc Cat _e.gacL.]
requirements. In case (1), the quality group classificatiorr of the relief valves is as currently required for these components; i.e., Quality Group _A (ASME Section III, Class 1). In case (2), the quality group classification of the piping and safety valve (s) beyond the proposed block valves would be Quality Group A. The safety valve (s) are isolated only during power oper-ation but are required to function during startup or shutdown conditions which are part of nonnal reactor operation. Therefore, Part (2)(ii) of 50.2(v), Reactor Coolant Pressure Boundary definition which states, "The second of two valves normally closed during normal reactor operation in system piping which does not penetrate primary reactor containment" is not applicable. The portion of 50.2(v) Reactor Coolant Pressure Boundary definition which is applicable is Pcrt (2)(111) which states, "The reactor coolant system safety and relief valves." Forcase(3),the
Contact:
R. Kirkwood Ext. 27754 90017156 8 001 1O
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- quality group classification of relief valve (s) that are added to auxiliary systems which are connected to the reactor coolant system would be the same as that of the connecting system 7 assuming the relief valve (s) are located outside the reactor coolant pressure boundary. The auxiliary systems which would be modified by the addition of relief valve (s) are currently classified Quality Group B (ASME Section III, Class 2).
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Robert Kirkwood, Plant Systems Division of Systems Safety cc: D. Ross T. Ippolito G. Mazetis S. Israel S.
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