ML20003G570
| ML20003G570 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 04/23/1981 |
| From: | Clark R Office of Nuclear Reactor Regulation |
| To: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8104300122 | |
| Download: ML20003G570 (5) | |
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NUCLEAR REGULATORY COMMISSION r.
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E WASHINGTON, D. C. 20555
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April 23, 1981 Docket No. 50-317 Mr. A. E. Lundvall, Jr.
Vice President - Supply Baltimore Gas & Electric Company P. O. Box 1475 Baltimore, Maryland 21203
Dear Mr. Lundvall:
In the process of reviewing the report of the Control Element Assembly Group Withdrawal (CEAW), Combustion Engineering Report CEN-121(B)-P submitted on June 26, 1980, we find the additional information as detailed in the enclosure is needed to complete our review.
Please provide the information at your earliest convenience; however, in order to maintain the schedule for completion of our continuing review it should be no later than 60 days following the receipt of this request.
Sincerely.
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Ro5er A. Clark, Chief Operating Reactors Branch #3 Division of Licensing
Enclosure:
Request for Additional Information cc w/ enclosure:
See next page 1
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Baltimoro Gas and Electric Company cc:
James A. Biddison, Jr.
Ms.' Mary Harrison, President Ceneral Counsel Calvert County Board of County Commissioners Baltimore Gas and Electric Company Prince Frederick, MD 20768 P. O. Box 1475 Baltimore, MD 21203 U. S. ' Environmental Protection Agency Region III Office George F. Trowbridge, Esquire Attn: EIS Coordinator Shaw, Pittman, Potts and Trowbridge Curtis Building (Sixth Floor) 1800 M Street, N. W.
Sixth and Walnut Streets Washington, D. C.
20036 Philadelphia, PA 19106 Mr. R. C. L. Olson Mr. Ralph E. Architzel Baltimore Gas and Electric Company Resident Reactor Inspector Room 922 - G&E Building NRC Inspection and ' Enforcement P. O. Box 1475 P. O. Box 437 Baltimore, MD 21203 Lusby, MD 20657 Mr. Leon B. Russell Mr. Charles B. Brinkman Plant Superintendent Manager - Washington Nuclear Operations Calvert Cliffs Nucledar Power Plant Combustion Engineering, Inc.
Daltimore Gas and Electric Company 4853 Cordell Avenue, Suite A-1 Lushy, MD 20657 Bethesda, MD 20014 Bechtel Power Corporation Mr. Bernard Fowler Attn:
Mr. J. C. Judd President, Board of County Connissioners Chief Nuclear Engineer Prince Frederick, MD 20768 15740 Shady Grove Road Gaithersburg, MD 20760 Director, Criteria and Standards Division Office of Radiation Programs (ANR-460)
Combustion Engineering, Inc.
U. S. Environmental' Protection Agency '
Attn:. Mr. P. W. Kruse, Manager Washington, D. C.
20460 Engineering Services P. O. Box 500 Mr. W. J. Lippold, Supervisor Windsor, CT 06095 Nuclear Fuel Management Baltimore Gas and Electric Company Public Document Room Calvert Cliffs Nuclear Power Plant Calvert County Library P. O. Box 1475 Prince Frederick, MD 20678 Baltimore, Maryland 21203 Dir'ector, Department of State Planning Ouality Assurance Department 301 West Preston Street Administrator, Power Plant Siting Program Baltimore, MD 21201 Energy and Coastal Zone Administration Department of Natural Resources Mr. R. M. Douglass, Manager Tawes State Office Building Ouality Assurance Department Annapolis, MD 21204 Room 923 - G&E Building Baltimore Gas and Electric Company P. O. Box 1475 Baltimore, MD 21203
ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION CEN-121(B)-P (CEAW)
CALVERT CLIFFS, UNIT NO. 1 1.
Demonstrate that the CEAW event is' calculated at the most reactive core condition for a given operating cycle.
2.
Is the analysis intended to cover the condition of a partial bank with-drawal in,which all rods are not withdrawn?
3.
What rod bank was assumed withdrawn in determining the red shadowing factor (RSF) at each node? Is this choice conservative?
4.
ANISN is used to evaluate the percent change in detector response per degree change in moderator temperature. Are changes in moderator temper-K ature in the core bypass, and downcomer regions accounted for separately?
How are axial effects accounted for in the evaluation of the detector response sensitivity to power shifting due to moderator temperature changes?
l 5.
Is the SHADRAC calculation done in 2-0 or 3-D? If the calculation is
(
i 2-D, how are 3-D effects accounted for?
C.
The radial peaking (F ) does not always decrease when liic CEAs are with-R drawn.
Is the assumption of a decrease in radial peaking implicit in the CEAW i
analysis?
7.
How does the conservatism of the initial conditions included in Table 4-1 compare to the conservatism of those used in CENPD-199 for the CEAW analysis?
8.
A Temperature Shadowing Factor (TSF) has been assumed in the calculation.
Since the TSF depends on water thickness. and geometry, for what plants l
is this value applicable?
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i 2-9.
Demonstrate that the selection of the parameters listed in Table 4-1, together with the ranges in gap thermal conductivity, moderator temper-ature coefficient, and CEA worth Invesigated, leads to the required absolute minimum in DNBR.
- 10. In the calculation of time of minimum DNBR with TORC, are the initial integrated radial and axial power distributions used? If so, what error is introduced by this approximation?
11.
In view of the 3-D nature of this transient, how has the conservatism of' the CEAW analytical methods with respect to SAFDLs been demonstrated for initial and reload cores?
- 12. Which CEA banks are assumed to be withdrawn during the CEAW event described in Section 3.17
- 13. Discuss if and how temperature shadowing effects are accounted for in QUIX.
- 14. The change in overpower margin at the time of minimum DNBR is determined from the change in the axial power shape and radial peak for the range of ASI within the allowable DNB LCD band. How is the rate of change of overpower margin with resper, To integrated radial peak and axial shape index established? Are the ranges and resulting values co'nsidered here conservative and adequate to represent extreme CEAW situations (i.e., large CEA'W reactivity rates, core conditions characterized by large reactivity inventories, worse control bank configurations, strong temperature shadowing effects, etc. ) ? Are the sensitivites (rate of change of overpower margin with respect to integrated radial peak and axial shape index) actually constant and if not what is their variability?
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_ 15. In determining B, what specific axial shape index shift and radial 3
peak decrease is used? For example, is the axial shape index shift determined from QUIX caiculations'at initial and minimum DNBR state-points?
16.
There seems to be an inconsistency in the expression giving R0PM (item 8, page 5-3): B is in units of power while B is OPM (a ratio of powers).
2 3
Please explain.
- 17. This analysis assunes first order perturbation theory in the calculation of the net penalty factor, B. Demonstrate that the anticipated perturbed 3
reactor conditions will result in a rela'tively small (much less than unity) value of B /B.
If during operation, this assumption is violated and B 3 2 3
approaches B ( how will the RPS sense this condition and prevent violation 2
of safety limits?
- 18. Describe how the chang
- in 3-D peaking (page 5-4) is determined.
- 19. Significant sources of uncartainty include instrument reponses, calculational uncertainties in shape annealing, rod shadowing factors, the components of "1
the penalty factor 8, and the calculational uncertainties implicit in th$
's 3
use of CESEC. How are these uncertainties accounted for in the analysis?
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