ML20004C119
| ML20004C119 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 04/24/1981 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| LSO5-81-04-031, LSO5-81-4-31, NUDOCS 8106010554 | |
| Download: ML20004C119 (5) | |
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April 24,1981 Docket No. 50-153 LS05-81-04-031 Mr. David P. Hoffman fluclear Licensing Administrator Consumers Power Company 1945 W. Parnall Road Jackson, Michigan 49201
Dear Mr. Hoffman:
We are continuing our review of the reactor physics methodology for the Big Rock Point Plant and have found that additional information described in the enclosure to this letter is needed. We request your respor.se witnin 45 days of your receipt of this letter.
Sincerely, itsje i h.
'I 4
ennis M. Crutchfield, CF ef Operating Reactors Branch #5 Division of Licensing
Enclosure:
As stated cc w/ enclosure:
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Mr. David P. Hoffman April 24,1981 CC Dr. John H. Buck Atomic Safety and Licensing Appeal Board U. S. Nuclear Regulatory Cornission Washington, D. C.
20555 Ms. JoAnn Bier 204 Clinton Street
'Charlevoix, Michigan 49720 e
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REQUEST FOR ADDITIONAL INFORMATION BIG ROCK POINT PHYSICS METH0COLCGY A first reading 'of the document describing the Big Rock Point Physics
-Methodology leads to the conclusien that the GROK code, with input preparation from CASMO, P00-7 and other standard cross section preparation codes, is used for both reload design' and analysis and as a' replacement for or adjunct to the orvuess compute r.
When used for reload applications the code calculates power distributions, critical red patterns at zero power and at operating conditions, rod sequences and rod worths within the sequence, reactivity coefficients (void and Coppler),
power distributions and margins to thermal limits. For core follow (process computer) applications the code is used to calculate margins to thermal limits, segment burnups, and flux wire activation p'rofiles (for cecoarison with measurements )
1.
Please verify, clarify, or modify the above understanding, as appropriate.
2.
For those parameters which are to be used as input to safety analyses please provide the following:
a.
The accuracy with which the parameter is calculated including the supporting da ta.
Is the comparison with experiment, with higher order calculation, or other?
b.
Coaparison of results of GR0K with those of the code used to calculate
.oe carameter for the FSAR analyses or the currently used reference analysis for each event.
c.
Indicate whe the nominal value is used in the safety analysis or is the uncertainty added before comparison with safety analysis value?
l 3.
A brief description of the role GROK plays as a process cceputer surrogate.
What parameters does it calculate? How are inputs obtained (i.e., is there a-direct connection from reactor to computer or is GROK used only on an' -
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b' hat is the accuracy of the calculated quantities?
Ara nominal values used to co.mpare with o;:erating limits (i.e., the limits themselves take into account the uncertainties) or are ;ncertainties added before comparing' 4.
With respect to the fluxwire measurements please provide esticates of the accuracy of these measurement for axial ;;cwer distribut'on in a single four assembly cluster and for makino radial power distribution deteminations.
5.
Provide information with respect to initial critical configurations in ter.s of d tb as well as the number of notches.
6.
The fluxwire - GROr corparison data in the recort should be sumarized to nrovide calculaticnal uncertainties for radial and axial ::esking factors and any other power distribution factors used in safety analyses or core follow.
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