ML20031D819
| ML20031D819 | |
| Person / Time | |
|---|---|
| Site: | Green County  |
| Issue date: | 03/23/1976 |
| From: | Check P Office of Nuclear Reactor Regulation |
| To: | Deyoung R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20031D800 | List: |
| References | |
| FOIA-81-236 NUDOCS 8110140254 | |
| Download: ML20031D819 (4) | |
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.,I R. DeYoung, As'sistant Director for Light Water Reactors, DPM FIRST ROUND QUESTIONS FOR GREENE COUhTY Plant Name:
~ i Greene County Nuclear Power Plant Docket Number:
50-549 Licensing Stage:
CP Milestone Number:
05-23 Responsible Branch LWR-5 and Project Manager:
J. Curry Technical Review Branch:
Core Performance Branch Requested Completion Date:
March 19, 1976 Review Status:
First Round Questicas Enclosed are first_round questions on the PSAR for Creene County from the Physics section of the Core Performance Branch.
P. Check, Chief Core Performance Branch
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Division of Systers Safety Office of Nucicar Reactor Regulation
Enclosure:
First Round Questions cc:
S. Hanauer istribution:
F. Schroeder Dochet File R.' Boyd
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NRR Reading File D. Vassallo QPB Reading File J. Curry P. Check W. Brooks
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W. Mcdonald
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See attached sheet for concurrences.
'. " 8110140254 810906 PDR FOIA BROWN 81-236 PDR
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FIRST ROUND QUESTIONS - CF 'ENE COUNTY NUCLEAR PLANT 232.0 Reactor Physics Section - Core Performance Branch 232.1 Specify the fue1' enrichment for each of fuel regions shown in (4. 3. 2.1)-
Figure 4.3-1.
Indicate on Figure 4.3-2 the location of the different loadings of th'. Burnable Poison Rod Assemblies and the relative loadings (e.g., low, medium, high).
232.2 Discuss quantitatively the peaking factor effect of Axial Power (4.3.2.2.6)
Shaping Rod Assembly misalignment.
Present values of peaking factor increase as a function of misalignment for the worst case rod.
232.3 Why is the moderator coefficient at initial critical conditions (Table 4.3-5) the same as'that for the Febble Springs Reactor when the boron concentration for Greene County is 1582 ppm compared ~with the Pebble Spring value of 1714 ppm?
232.4 The normal radial power distribution given in Figures 4.3 (4.3.2.2.1) 4.3-16 are identical to those for the Pebble Springs reactor in, spite of the difference in enrichment between the two reactors.
Please explain this fact.
232.5 Provide more discussion of the effects of the various fuel loading (4.3.2.2.6) errors that may be made.
In particular, provide assurance that any misloading error that can cause unacceptable thermal consequence is detectable by incore or excore instrumentation.
232.6 The Doppler coefficient for Greene County is significantly more (4. 3. 2. 3) negative for intermediate and operating temperatures than that for the Pebble Springs reactor. Please explain the difference.
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232.7 In Tables 4.3-9 cnd 4.3-10 thn Doppler deficit (0 to 100% powsr)
(4.3.2.4) has the same value as that for the Pebble Springs reactor.
Explain the similarity in view of the differences in Doppler coefficient.
232.8 This section implies that radial power distributions other than (4.4.3.2) the design distribution are used in establishing axial imbalance Please expand the discussion in this section to cl$arify limits.
the manner in which imbalance limits are obtained.
232.9 Justify the use of 3600 Mwt as the initial power for full power (15.1 transients rather than 3672 Mwt (3600 x 1.02).
232.10 Provide the scram reactivity curves (reactivity inserted as a (15.1) function of time) that are used in the analysis of Chapter 15.
Describe the manner in which this curve is obtained, including the power shape used and the variation of power shape with time during the insertion.
(Previde both full power and low power curves.)
232.11 Discuss the effect of transients on instrument response.
For (15.1) example, does 112% power during a transient correspond to 112%
during steady state?
232.12 The nominal value for the Doppler coefficient on Figure 15.1.2 (15.1.2) 3
- 4 does not agree with the full power value from Chapter 4.
1 Please clarify the discrepancy.
232.13 Discuss the case of the withdrawal of a single CRA from the core (15.1.2) as a function of power level.
232.14 The low pressure trip value (2000 psig = 2015 psia) dor.s not agree i
(15.1.3) 1 with that in Table 15.1-2 (1995 psia).
Please explain the discre-pancy.
Are these values trip setpoints or do they include uncertainties?
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232.15 What is the effect on the aadlysis of this accident of using (15.1.3) more negative values of the Doppler coefficient which correspond to those in Chapter 47 232.16 Provide arguments to show that the limiting transient is caused (15.1.3)
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by dropping the maximum worth rod.
232.17 The rod ejection analysis at zero power extends to only 0.75%
(15.1.20)
AK/K while the Technical Specifications (Section 16.3.9) permit potential ejected rod worths at zero power of 1.0% AK/X. Please resolve the discrepancy.
232.18 Provide clarifications of the manner in which three-dimensional (15.1.20) effects are accounted for in the rod ejection analysis. The WIGL2 comparison extends only to rod worths of 0.5% AK/k, but the point kinetics analysis is used at higher rod worths.
Justify the conservatism of the analyses at the higher worths.
232.19 For the limiting rod ejection accident provide, in addition to (15.1.20) the number of rods experiencing cladding failure, the number of '
rods in which the fuel reaches the melting temperature.
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