ML20037B169
| ML20037B169 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 04/21/1978 |
| From: | Ziemann D Office of Nuclear Reactor Regulation |
| To: | Reed C COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8009080540 | |
| Download: ML20037B169 (4) | |
Text
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APR 211978 -
t,Cdc ket TBAbernathy NRC PDR JRBuchanan Local PDR ACRS (16)
ORB #2 RDG bcLc t ' :. 50-10 VStello BGrimes OELD' OI&E (3)
DLZiemann P0Connor Comonwealth Edison: Company HSmith ATTN:
L'r. Cordell Reed DEisenhut-Assistant Vice President Post Office Box 767 Chicaco Illinois 60690 Gentler.en:
He are reviewinc_ the Dresden Station Unit 1 Plant Transient /.nalyses sule.itted by your letters dated November 8,1977 and February 16, ic7P..
To continue our revie'er the infomation described in Enclosure A is required.
Flease provide the requested information by "ay 3D,1978.
Sincerely, 0:.c '
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Dennis L. 7te. ann, Chief Operatin? Reactors Brcnch #2 Division of Operating Reactors
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As stated cc: See next page 4
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Mr. B. B. Stephenson
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'D-1 P.EQUESTS TC2 ADDIT 10*!AL I!!r0P.M; TIC'f 1)
Provide a description of the PTS BL',R 2 cos!es.
Describe or reference-
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a description of the Exxon Nuclear Corporation PTS BWR codes,
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g and describe all modifications-nade to those c6 des for applicability
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to D-1..
Justify that the codified -codes provice adequately
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conscrvative MCPR and pressure results for D-1 for al1~ transients
+ f.i:7, analyzed.
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2)
Provide.a description of the TRI-LUX code in sufficient detail so thatL
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- we can _ determine by independent review that the code will yield y
conservative MCPR results for the control rod withdrawal event t ir 3 ;,,
D-1.
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- 3) Justify that the initial control rod pattern chosen.for analysis -
of the rod withdrawa.i event is the most~ limiting, In psr_ti.cular:
1) state that the_ initial rod-pattern occurs during the normal
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rod withdraual sequence, and provide' justification that out-of-
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sequence rod rcooval before the withdrawal event. is not credible; or fn
- 2) specify the rod or rods that have already bern assumei uitMrawn (out of.sequenc6) before the withdrawal event Anitiates, and justify that the case ' chosen is the worst ndible cr.sc.
- 4) Do all of the EOC and E0C MCPR cntries in Table 1.i of XG-MF-77-46 lT rep.esent results of actual 4 MCPR calculations, initiated at C, :,#
!dR.= 2.11- (4 loap cascs)^ and 2.6f, (3 Ioop cases)?
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the initial MCpR and the resulting cciculated 6 MCPR for the actuti calculations that were perforr.ed and substepntly cdjusted to produce the table entry.
- 5) Specify and provide justification for the conservatism of the
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pump speed vs. time (inforcation in Table 3.5).
- 6) Please clarify or correct Table.3.2 which snows peti:
b' safety valve flows in the range of only 30 to 50 lbm/sec.
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7)
Explcin uhy steam flows assumed for both the 700 Mat and the 525 Mvit cases (Table 2.1) are both 1.6 x 106 lbm/hr.
8)
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Please explain (in more detail than on pg 16) why turbine trip without bypass is nore limiting ct P.0C.
It is not cicar that the less negative naderstor reactivity coefficient at' ECC would cchpens6te for the slower scrcn reactivity insertion et ECC.
9)
Flease exp'.ein the Coppici Coefficient-l:altipliers' (Tchle 2.2).
Quantitatively express the conservatism fcctor (compared to a
- best estimate value) that is included in the Doppler coefficien
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through use of these multipliers.
10), Picese expicin the Void Coefficient Multipliers (Table 2.2).
QJtntitctively express tfie coreerva'tism factor (compared to c best 03 tim.te veluc) that is included in the Void coefficients through use of these multipliers.
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