ML19308B995
| ML19308B995 | |
| Person / Time | |
|---|---|
| Site: | Crane, Davis Besse  |
| Issue date: | 01/11/1979 |
| From: | Cartin L BABCOCK & WILCOX CO. |
| To: | Luken R BABCOCK & WILCOX CO. |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001170737 | |
| Download: ML19308B995 (3) | |
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E. A. Womack B. A. Karrasch THE BASCOCX & WILCCX COMPANY B. M. Dunn POWER GENERATION GROUP g, O. Vosburgh To l
R. C. LUKEN, NUCLEAR SERVICE E. W. Swanson J. T. Willse From A (latb' N. H. Shah L. R. CARTIN, PLANT INTEGRATION (2835) es m.s File No.
Cust.
or Ref.
ECO Suoj.
Date JANUARY 11, 1979 RESPONSE TO TECO L..4scR TBW-505 lm........................,,,
Reference:
1.
C. R. Domeck to A. H. La:ar, "DB-1 Dual Level Se: points on Steam Generators for Auxiliary Feedwater",
TBW-505, dated January 2, 1979 2.
L. R."Cartin to R. C. Luken, "TECO Status Report",
dated December 19, 1978 3.
Letter Report, "Steas Generator Level Effects on Plant Operation", dated December 21, 1978 At your request, the recent TEco letter (Reference 1) has been reviewed by the appropriate analysis groups. The following infor=ation provides a summary of our approach to answering each question including cost and schedule requirements.
Question 1.
ECCS will review the natural circula: ion test conditions and provide a co=panson with typical small break transient conditions. Their intent will be to'show that the comparison between the natural circulation conditions observed.
'during a small break and the plant test is inappropriate and that the natural circulation test provided no new information that would invalidate the small break analysis (BAW-10015). Support from Control Analysis will be required to interpret the natural circulation test data and to understand the actual tech- -
nique employed by TEco to induce a natural circulation flowrate.
, Question 2: This (question requests justification that the time for. filling the.
- 0TSG to 120 inches is consistent with the small break analysis in which'no time ECCS w!11 review the reported small break spectrum to deter-
- idelay was assumed.
mine the interval between reactor trip and ESFAS initiation of the HFI system and develop a rationale which supports the continued validity of the. topical.
~
l For the interum operation centrol scheme, ECCS will also provide,a maximum time period, following ESFAS actuation, during which the operator must place the SFRCS in the auto-essential mode to achieve a 120-inch steam generator level. This_ additional infor=ation is required since the operator could'havam e the auxiliary feedwater l system in manual, controlling s. team generator level at t
- 35 inches, prior tolESPAS indication that a saall break has occurred. No
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CRAFT calculations are planned to support the response to this question.
B6W's response will be based on engineering experience to deduce that the expected tice delays would no: prevent achievement of a high steam generator level when required for LOCA mitigation.
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- a RESPONSE TO TECO Lt.a:R TBW-505 - PAGE : - JANUARY 11, 1979 Ouestion 3: Control Analysis will evaluate the severity of an actual loss of offs:.te power incident compared to both the Technical Specification and other docu=entation used as input to the stress analysis performed on DB-1.
The intent is to show that appropriate li=its (NDT but not fuel compres-sion, normal cooldown, etc.) are not exceeded. This evaluation will include both SLB and FWLB based on RCS pressure-temperature curves to be provided by Safety Analysis. Safety Analysis will also prepare a statement of t',e affects
,that the dual setpoint auxilia.y feedwater control scheme would have.on both ishort term (published) and long tera (unanalyzed for DB-1)' system risponse, for Chapter:15 eventsa Question 4: ECCS will provide a discussion of the LOCA-licensing basis for DB-1 to include reference to appropriate topical reports and/or other work on similar plants which supports that Davis-Besse 1 is in _conformance with Direct reference to the Davis-Besse 1 specific analysis using
,10CFRSO.46.
.a ten-foot auxilia.y.feedwater_ level is.not-planned. ras.noted in Reference _1, additional work would be required to-assimilate these extra analyses into a iform suitable.for_an NRC submittai...it is. felt that this work should be, Linitiated so th_at a responsive submittal, due to possible future requests
!by. the NRC, can be made.:
Question 5: A condensed version of Reference 3 along with supportive state-cents that the ECCS topical remains valid will be prepared as a 10CFR50.59 review of the dual level setpoint change. The objective is to provide refer-ence to supportive an'alysis, which has been done by B5W,-to conclude that no changes are necessary to the Davis-Besse-1 Technical Specifications and that no unreviewed safety issues exist with the dual setpoint change.
Responses to Questions 1 through 5 (excluding documentation of ECCS ten-foot level runs) above are scheduled to be released for in-house review by February 7, 1979 and to be submitted to you in final for= by "ebruary 13, 1979. Resources required within Plant Design are as follows:
ECCS Analysis Unit -
80 manhours Control Analysis Unit -
120 manhours Safety Analysis Unit -
60 manhours Plant Integration Unit -
40 manhours Work Authoritations for the above work efforts, where required, are attached.
Please review the proposed approaches to the questions with the customer to ensure that B5W has interpreted their questions correctly. Work will proceed on the basis of B5W's present understanding of the questions pending release of necessary funding.
[ Documentation'for.theten-footECCSruns3.naformsuitable.foranNRC, tsubmittal is an optional work effort. A Work Authoritation requesting 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> to complete this task is also attached. We feel that this work should take place and a completion date of March 30, 1979 is proposed.
In addition to preparation of responses to Reference 1, two additional items are currently outstanding. First, the po,sitions (Reference 2) prepared in h, D
m RESPC';SE TO TECO LETTER TBW-505 - PAGE 3 - JANUARY 11, 1979 response to TECo's previous letter (TBW-303) re=:in unchan3ed. Your formal response to TdB-303 should thus be consistent with Referenet 2.
- Secondly, the letter report (Reference 3) should be ; considered prelimi. nary pending comple-tion of a calculational file to support the loss-of-feedwater analysis with
' failure of the operator to control. steam generator level at,35-inches. i B.' M.
Dunn indicates that this work will be completed by mid-Janus.ry 1979. A formal release of the letter report, which incorporated TECo comments, will take place approximately five days following completion of the E'CS calculational file.
With completion of the above work efforts,'all known activities required to
- support the Davis-Besse 1 dual setpoint control scheme will be accomplished.
To acquire a retrie' able record of events' and analysis efforts, a historical v
file will also be prepared.
It is anticipated that the following information (in complete form or by reference) will be compiled:
1.
Problem identification.
2.
TECo-B5N Meeting Minutes.
3.
Documentation to support B&W analyses or responses to TECo/
NRC questions;.to include:
a.
Control Analysis work to suppor: the 35-inch. steam generator level during anticipated transients.
b.
35W's review of the natural circulation test data. -
- c. [ Documentation of the ECCS runs with a ten-foot Auxiliary
)Feedwater Level.
d.
Reference 3 and supportive documentation.
e._ Results from the outstanding ECCS Analysis [(small break' 2
l with R.C. Pumps and main feedwater operative).
f.
Support which justifies the continued validity of the ECCS topical.
- 4. l Review' of other 177 F.A. Plant'. Auxiliary, Feedwater System [to,.
/ determine if_ pressurizer level is a problem and if the ECCS analysis fis compromised. This review may result in recommendations to other ~
customers to improve plant control.
It is felt that the comoilation of the above infor=ation in one place will allow B5W to provide better customer support if additional NRC questions are received.
To complement the above, a formal report summarizing all activities leading to j
final resolution of the problem could also be prepared for TECo.
Please advise if TECo would desire a formal report of this nature. Anticipated costs for such a report would be approximately ISO c:anhours.
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