ML20027A721
| ML20027A721 | |
| Person / Time | |
|---|---|
| Issue date: | 12/30/1981 |
| From: | Mazetis G Office of Nuclear Reactor Regulation |
| To: | Lobel R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20027A678 | List:
|
| References | |
| FOIA-82-543 NUDOCS 8202030307 | |
| Download: ML20027A721 (2) | |
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- El:0RA!! DUP. FOR:
Richard Lobel, Section Leader, Section A Auxiliary Systems Bran:h, DSI FR0":
Gerald liazetis, Scction Leader, Section C Reactor Systems Cranch, DSI SU3 JECT:
REQUIRE!1ENTS FOR ACCEPTA0ILITY OF FEED Af!D BLEED The Reactor Systems Branbh has the following comments on the Draft 1:morandum from L. Rubenstein, to R. !*,attson, "Propo:ed f;RC Position on Acceptable l'ethods of Industry Compliance with the Auxiliary Feed-water System Reliability Criterion". Our co: rents relate to the accepta-bility of reliance on feed and bleed as a method of improving the reliability of recovering from a loss of feedstater event. We will be abailable to discuss these comments with you.
Iten 2a is as follows:
2.
An analysis must show that:
a.
An acceptable amount of time is available to an operator to make the decision of whether or not it is necessary to open PORVs and depressurize the plant.-
This item should be amended to require that the time available for operator action should as a minimum, meet the criteria of Af;SI fi[j0 for condition IV events.
Its 4 is as follows:
4.
The feed and bleed prodedure can be done at a pressure that will not cause a significant increase in the risk of reactor vessel failure, taking into consideration the injection of cold water.
This requirment should be expanded to include the following considerations:
a.
Procedures should be developed to alert the operator of conditions which might lead to vessel failure and to provide reedial action, b.
The adequacy of instrumentation utilized by the operator to assess reactor vessel temperature for the purpose of assuring tiDTT liaits are not exceeded should be dddressed.
Under feed and bleed conditions in the absence of feedwater flow to the steam generators natural circula-tion would not occur throughout the reactor systm.
Plant temper'ature
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instrumentation locations in the loop and at the core exit may not be adequate _to_as.s.e_ss_ coolant temperatures within the downcomer and
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The degree of mixing between the inccmirm ECCS streams and rt. actor vessel downconer content:, slaui; __ cOrcssed. Cal-culations or instrumentation unich :..ay rair on bulk tmperet'...
information to the operator may not ade:pately describe local conditions in proximity to the ECCS injection location.
The bulk temperature should be related to the local temperature of the injected fluid adjacent to the vessel tall.
d.
Stress levels within the reactor vessel should be evaluated including the effect of non-uniform fluid conditions and the location of reactor vessel welds.
e.
The thermal shock on the steam generator tubes from the even'tual restoration of auxiliary or main feedwater should be evaluated.
Itm 5 is as follows:
5.
The PORV controls and motive power for operation must be safety grade.
This its should be modified so that the PORVs and associated controls do not have to be safety grade unless they are relied upon in the feed and bleed process.
Gerald R. I'.azetis, Section Leader Section A Reactor Systems Branch Division of Systems Integration I
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W. Jensen B. Sheron G. liazetis T. Spets DISTRIBUTION L. Rubenstein CENTRAL FILES R. itattson RSB RF
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