ML19224B883
| ML19224B883 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse, Oconee, Arkansas Nuclear, Crystal River, Rancho Seco, Crane  |
| Issue date: | 05/18/1979 |
| From: | Williams F Office of Nuclear Reactor Regulation |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7906270120 | |
| Download: ML19224B883 (3) | |
Text
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13 Date 5-18-79
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MEMORANDUM FOR: Dar-all G. Eisenhut, Deputy Director, Division of 6.f Operating Reactors THRU:
Steven A. Varga, Chief, Light Water Reactors Branch No. 4, Division of Project Management FROM:
F. J. Williams, Jr., Technical Coordinator, Division of Project Management
SUBJECT:
PROBLEMS - TMI BULLETIN RESPONSES Bulletin 79-05B
, Plant All B&W i
l Source Bulletin response, I&E Corments (Oconee)
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Resolution required for safety evaluation Yes s
Problem -
Item 4f calls for manual trip on low pressurizer level.
Attached information indicates the confusion on this requirement. Need to know whether 4f should be deieted and whether a high pressurizer level should be added.
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Assessment by Problea Group - None I
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Additional infomation available - Attaciisc (same argument proposed by 2 other licensees).
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Provide procedures and training to operating personnel for a promot manual trip of the reactor for transients that result in a pressure increase in the reactor. coolant system.
These transients include:
a.
loss of main feedwater b.
Main Steam Isolation Val 2 closure d.
Low OT3G level f.
low pressurizer level.
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Resc-mos e.
RESPONSE
Station Lirective 3.1.30, " Required Manual Trips of the Reactor," has been approved and distributed which requites the Control Room operator to =anually trip the reactor pro =ptly when transients that result in a pressure increase in the Reacter Coolant System occur. These specific transients are:
1.
Turbine Trip (At reactor power levels greater than 200 F?)
2.
Main Steam Stop Valve Closure (Two valves on same OTSO or all four valves) 3.
Low OTSG Level Station Directive 3.1.21, Loss of bbin Feedwater, previously required a canual trip of the reactor upon loss of both main feedwater pumps or upon loss of feed-water flow to the steam generators.
This Directive rc=ains in effect.
The required manual trip of the. reactor on low pressurizer level is consider -
inconsistent with the general concern expressed in this ttes of pressure increases in the reactor coolant system.
Low pressuriser level is associated with under-pressurization resulting f rom overcooling rather than overpressurization.
A
- eactor trip or. low pressuri er level would compound the transient as the priaacy heet soucce is removed.
Therefore, rather than adding a mandatory manual reactor trip, station procedures have been revised to require a prompt increase in reactor coolant make-up flow on decreasing pressuriner level in order to restore normal level.
l The above h ue been discussed and reviewed by all licensed personnel, r
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