ML20042C375

Forwards Draft Responses to Draft SER for Core Performance Branch.Responses Will Be Incorporated in FSAR Amend

ML20042C375
Person / Time
Site:	Perry
Issue date:	03/25/1982
From:	Davidson D CLEVELAND ELECTRIC ILLUMINATING CO.
To:	Schwencer A Office of Nuclear Reactor Regulation
References
NUDOCS 8203310315
Download: ML20042C375 (8)

Text

.

TliE C L EV E L A N D E L ECTRIC IL L U MIN AllN G C O M P AN Y P o. Dox 5000 o CLEVELAND, OHlo 44101 e TELEPHONE (216) 622-9800 e ILLUMINATING BLOG e $5 PUBLIC SoVARE Dafwyn R. Davidson #*"9 # O### C# ## "

f,#

VICE PRESIDENT

$YSTE M ENGINEEHtNG AND CONSTRUCTION g 0

??,

March 25, 1982 4 y n9,n g pg2 p. _-

Mr. A. Schwencer 5'A4 m:sy s rvr t-zd 3* ,

t Chief, Licensing Branch No. 2 h a:aree.ru W w '

l Division of Licensing P U. S. Nuclear Regulatory Con: mission {' Ya*j d {p, Washington, D. C. 20555 Perry Nuclear Power Plant Docket Nos. 50-440; 50-441 Response to Draft SER Core Performance Branch

Dear Mr. Schwencer:

This letter and its attachment is submitted to provide draft responses to the concerns identified in the Draft SER for Core Performance.

It is our intention to incorporate these responses in a subsequent amendment to our Final Safety Analysis Report.

Very Truly Yours,

/ k Dalwyn 1. Davidson Vice President System Engineering and Construction DRD: mlb cc: Jay Silberg John Stefano Max Gildner 1

0 0,

sj 9203310315 820325 PDR ADOCK 05000440 E PDR

s CPB-1 492.11 You have not cited the name, version, or reference (4.4.4.5) of the computer program used in this sub-section.

Letter from N. W. Curtis (Pennsylvania Power and Light Company) to B. J. Youngblood (NRC), " Response to NRC question on Susquehanna FSAR," dated March 25, 1982, states that name of the computer program is "ISCOR" and reference is " General Electric Document NE00-20953, May 1976, Chapter 4."

Please confirm ISC0R has been used for Perry.

What version number of ISC0R is the latest version?

Has this version been applied to Perry? If the reference of this version is different from GE Document NE00-20953, provide the document or the reference. Also describe any significant changes of this version of ISC0R code over the previous version of ISCOR.

Response

The computer program cited in Section 4.4.4.5 is named ISCGR. The ISC/.R computer program and another GE progran PANACEA (3 demensional BWR core simulator) use the same steady state thermal hydraulic mathematical module described in NE00-20953-A dated January 1977. The program ISC0R and the calculations used for Perry are consistent with the technical content of NE00-20953-A, dated January 1977 Perry FSAR Sub-section 4.4.4.5 description also corresponds to ISC0R j '

Version No. 5 which was used for Perry.

The details of ISC0R and its associated proprietary documentation are available for review at GE in San Jose.

cm-2 You have not cited the name, version, and reference (492.16) of the core wide transient analysis code (i.e., ODYN or REDY) and for the GETAB-MCPR evaluation of the transients. Please provide name, version, and reference of these two codes used for Perry.

Response

The REDY code, as documented in NEDO-10802, " Analytical Methods of Plant Transient Evaluations for the General Electric Boiling Water Reactor," was used for the core wide transient analysis as shown in Chapter 15. Limiting pressurization events evaluated with the ODYN code will be provided in the near future. All the GETAB-MCPR evaluation of the transients was performed with SCAT code as documented in NEDO-20566, " General Electric Company Analytical .Model for Loss-of-Coolant Analysis in accordance with 10CFR50, Appendix K." However, in order to make SCAT more compatible to 0DYN output, a modified version of SCAT has been prepared in conjuction with ODYN. The NRC was notified of this modified version of SCAT in a letter from GE's K.W. Cook to F. Schloeder and D. Eisenhut (MFN - 171 - 79) dated ,

July 20, 1979.

The Cook to Eisenhut letter indicates that the SCAT code, when driven by ODYN, can exhibit numberical in-stabilities which, unless accommodated by the user, may result in highly conservative a l CPR calculations. This is because of the explicit nature of the  !

SCAT numerical scheme.(Discontinuities in pressure rate causin oscillations in void fraction solution and a CPR calculations)g Since. i then, an implicit solution method has been applied to the vapor continuity equation. This stabilizes the void fraction solution and I removes the non-physical a CPR conservatism.

The ODYN/ SCAT results without user adjustments are compared with the results from the ODYN/ modified SCAT in attached Table 2* which is taken from ,

the aforementioned letter. The modified SCAT was also verified by the i I

comparisons shown in Table 1, which is also taken from the aforementioned letter. In this case, both SCAT and the modified SCAT are stable with respect to REDY, which is used in most of the FSAR Chapter 15 transient analyses. As can be seen from Table 1, the a CPR comparisons from SCAT and modified SCAT are almost identical.

The above explanation was given in the Cook to Eisenhut letter and is repeated here for convenience purpose only.

I i

• The numberical instabilities under the SCAT results column are clearly indicated here to show the unreasonableness if user accomodations are not considered.

' ,%i

.;. . , f -

TALE 1 h

n' a CPR COMPARISIONS (REDY INPUT)

A CPR SOURCE OF SCAT REVISED VERSION PLANT EVENT INPUT RESULTS RESULTS BWR 3 TTNBT REDY 0.2912 0.2964 FWCF REDY 0.3284 0.3250 BWR4/218/560 LRNBT RE0Y' O.2795 0.2787 PLANT A FWCF RE0Y 0.2399 0.2393 BWR4/218/560 LRNBT/RPT RE0Y 0.0996 0.1064 PLANT B BWR4/251/764 TTNBT REDY 0.2337 0.2356 PLANT C FWCF REDY 0.0737 0.0720 BWR4/218/560 TTNBT RE0Y 0.1780 0.1881 PLANT 0 TABLE 2 a CPR COMPARISONS (00YNINPUT) a CPR SOURCE OF SCAT REVISED VERSION PLANT EVENT INPliT RESULTS* RESULTS BWR4/218/560 LRNBT 00YN 0.271 0.226 PLANT 1 TTNBT/RPT 00YN 0.1765 ~0.1243 LRNBT/MST 00YN 0.221 0.185 BWR4/183/368 TTNBT ODYN 0.2522 0.2266 BWR4/218/560 LRNBT 00YN 0.2798 0.2461 PLANT 2 FWCF ODYN 0.2487 0.2189 LRNBT - Load rejection without bypass transient i TTNBT - Turbine trip without bypass transient l RPT - Recirculation pump' trip MST - Measure scram time of insertion FWCF - Feedwater Controller Failure PLANT - Plant type / vessel size /No. fuel bundles I

• Results are based on raw input data without user adjustments l

l KWC:vm/1244

! 7/19/79 i

M CPB-3 Provide by separate amendment, the operating limit MCPR as calculated by including the ODYN metheds.

Response

The operating limit minimum critical power ratio (MCFR) will be

! provided by separate amendment with the results of the ODYN analysis

.; for Perry, scheduled for submittal in April 1982.

i e

I e

9

.3 t

i f

, n . - - - - -w

4 _. . _ - _ . _ _

e

.DSER Item CPB-4 Single loop operation is not permitted unless supporting analyses are provided and approved.

Response

- Operation with one recirculation loop out of service shall be limited. A reasonable time will be allowed for restarting that loop or for an orderly reactor shutdown. This will be identified in the technical specifications.

i 4

s 9

_. _, , , , _ , ,4,

DSER Item CPB-5 Operation in a natural circulation mode is not permitted while we continue our generic evaluation of thermal hydraulic stability for BWRs.

Response

The technical specificatiens shall preclude reactor operation in the natural recirculation mode except to allow completion of the natural circulation testing (test mode 4) that is required by the NRC.

r 4

I i

I-

[

E s

' {<

d DSER' Item CPB-6 The core flow should be checked at least once

... every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to account for possible effects of crud deposition.

j

Response

.The t'e chnical specifications will address checking core flow every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to account for possible effects of crud deposition.

2 4

1  %

i i

l c

l

....r . - - - , , - , .,-