ML18046A885
| ML18046A885 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 08/20/1981 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| LSO5-81-08-038, LSO5-81-8-38, NUDOCS 8108260005 | |
| Download: ML18046A885 (4) | |
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t Docket No. 50-255 LS05-81-08-038 Mr. David P. Hoffman Nuclear Licensing Administrator Consumers Power Company l945 W Parnal1.Road Jackson, Michigan 49201
Dear Mr. Hoffman:
August 20, l 98i Ji
SUBJECT:
DESIGN BASIS EVENTS REPORT {MISSING PAGES)
PALISADES It has come to our attention that some copies of the enclosure to our letter of July 17, 1981 on the design basis events for Palisades were missing two pages.
We therefore request that you insert the attached pages in the appropriate locations in the July 17, 1981 report.
Enclosure:
As stated cc w/enclosure:
See next page 8108260005 1810820 '.
POR AOOCK.05000255 P
POR
'N~9. FORM 318 (1~80) NRCM 0240
~.:
Sincerely, Dennis M. Crutchfield, Chief Operating Reactors Branch No. 5 Division. of Licensing OFFICIAL R~CORD COPY
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\\usGP0:1sa1-oos-960
Mr. David P. Hoffman cc M. I. Miller, Esquire Isham, Lincoln & Beale Suite 4200 One First National Plaza Chicago, Illinois 60670 Mr. Paul A. Perry, Secretary Consumers Pov1er Company 212 West Michigan Avenue Jackson, Michigan 49201 Judd L. Bacon, Esquire "
Consumers Pm-Jer Company
- 212 West Michigan Avenue Jackson, Michigan 49201 Myron M. Cherry, Esquire Suite 4501 One IBM Plaza Chicago, Illinois 60611 Ms. Mary P. Sinclair Great Lakes Energy Alliance 5711 Summerset Drive Midland, Michigan 48640 Kalamazoo Public Library
. 315 South Rose Street Kalamazoo, Michigan 49006 Township Supervisor Covert Tovmship Route 1, Box 10 Van Buren County, Michigan 49043 Office of thi Governor (2)
Room 1 - Capitol Building Lansing, Michigan 48913 William j. Scanlon, Esquire 2034 Pauline Boulevard Ann Arbor, Michigan 48103 Palisades Plant ATTN:
Mr. Robert Montross Plant Manager Covert, Michigan 49043 U. S. Environmental Protection Agency Federal Activities Branch Region V Office ATTN:
EIS COORDINATOR 230 South Dearborn Street Chicago, Illinois ff0604 Charles Bechhoefer, Esq., Chairman Atomic Safety and Licensing Board.
Panel U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Dr. George C. Anderson Department of Oceanography University of Washington Seattle, Washington 98195 Dr. M. Stanley Livingston 1005 Ca 11 e Largo Santa Fe, New Mexico 87501 Resident Inspector c/o U. S. NRC Palisades Plant Route 2, P. O. Box 155 Covert, Michigan 49043
consequences of this event would be less severe than those for a steamline break wit~ all pumps operating.
The radiological consequences of a break inside containment are less severe than for a break outside containment since the main steam isolation valves are closed, maintaining the isolation boundary inside containment.
(See Section 4.3.3.)
4.3.2 St~amline Break Outside Containment (Topic XV-2)
The blowdown rate for a break outside containment is lower owing to the venturi flow elements in the main steamline inside containment.
Thus, there is no return to power even for the worst breaks.
A break downstream of the isolation valve can be easily isolated, with very minor consequences, so it is not con-sidered further in the analysis.
Even assuming one MSIV.fails to close, the blowdown would be limited to the one generator.
The signs of a line break outside containment include:
- 1.
Rapid loss of pressure and level in one generator
- 2.
Release of steam.within the auxiliary building
- 3.
Full-scale, steam-flow indication
- 4.
Unusual loud noise
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Low pressurize~ pressure In response to the line break, the following protective actions occur automatically:
the reactor and turbine trip, the MSIVs close, main feedwater is isolated, auxiliary feedwater is started, and safety injection is actuated.
Immediate operator actions are taken to verify the automatic protection actions, as we 11 as to terminate auxiliary feedv1ater to the affected steam generator.
Decay heat is removed via the intact steam generator using the steam bypass to the main condenser (if available) or the atmospheric dump valves to remove energy with the a~xiliary feedwater system supplying water to the steam
- generator.
This method is used to cooldown to the shutdown cooling system initiation point.
If the shutdown cooling system cannot be used, the above method can be used to cooldown to close to 212°F.
An emergency connection to the fire water system is provided for supplying water through the auxi1iary feedwater system to ensure a w~ter supply to the steam generator if the condensate storage tank is lost.
A steamline break in the component cooling water (CCW) pump room could result in loss of the ctw system.
Actions in this event are identical to those required for a feedwater-line break in this area as discussed in Section 4.2.6.
A break between the coritainment penetration and the isolation valve cannot be isolated so the affected ste~m generator blows down completely to the atmo-sphere.
The licensee does not consider a break in this location to be credible because of increased pipe wall. thickness and surveillance of pipe welds'.
However, the licensee assessed the consequences of a steamline break between the containment penetration and the MSIV, from full power, and failure of one 39
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SUMMARY
For the majority of the accidents and transients normally analyzed for a pressurized water reactor, the licensee has provided analyses which are in general conformance with current regulatory criteria.
For some of the other events, NRC staff considers that the consequences are bounded by those of*
events that were evaluated.
Based on our reviews of the steamline break accident, the staff considers that single failure concerns have not been fully addressed.
The licensee should demonstrate that the consequences of a steamline break from full or zero power, with or without offsite power can be successfully mitigated with minimum, available equipment.
The minimum safeguards should be determined with due consideration of technical specification operability requirements and the most limiting single failure.
In addition, single failures in other systems that could worsen the severity of a break must be addressed.
Inadvertent opening of an atmospheric dump valve *(ADV) bn the iritact steamline or of all ADVs. due to a controller failure could increase tne steam removal, and thus plant cool down.
Failure of the MSIV in the unbroken loop to close is another single failtjre to consider, which could result in extremely severe consequences for both the core and containment.
As discussed in Section 4.3.1, the failure of a check valve in the LPSI discharge could permit overpressurization of the LPSI system by the* HPSI system during a safety injection.
This subject is further addressed under Topic V-11.8.
Explicit analyses have not been provided for feedwater-line breaks or. for loss of ac power to stati~n auxiliaries.
The staff has assessed the ability of {he plant to respond to these events based on available information.
We conclude that an adequate level of protection for the consequences of these events will exist \\vhen planned modifications to the auxiliary feedwater system are complete.
Generic analyses.provided by Combustion Engineering for such events as loss of feedwater flow and small loss-of-coolant accidents, have been factored into the assessment of event consequences even though the calculatioris in some cases are not licensing calculations.
The codes and evaluation models used by Exxon for the plant transient analysis have been previously accepted by the staff.
Ex~ept as noted, the assumptions and initial conditions are considered acceptable.
Analyses provided~in the FSAR were evaluated with unspecified Combustion Engineering codes.
The NRC staff considers that rio additional review of these is needed on the basis that good agreement exists with later results from the Exxon codes, that these events are typically nonl imiting, and that earlier staff reviews accepted the results.
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