ML20215L138
| ML20215L138 | |
| Person / Time | |
|---|---|
| Issue date: | 09/09/1986 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-2457, NUDOCS 8610280489 | |
| Download: ML20215L138 (53) | |
Text
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ACRS THERMAL HYDRAULIC PHENOMENA SUBCOMMITTEE MEETING MINUTES AUGUST 28, 1986 WASHINGTON, DC PURPOSE: The purpose of this meeting was for the Subcommittee to con-tinue review of the RES-proposed revision to the ECCS Rule - 10 CFR 50.46 and Appendix K.
ATTENDEES: Principal meeting attendees included:
ACRS NRC C. Michelson, Chairman L. Shotkin, RES D. Ward, Member W. Beckner, RES C. Wylie, Member N. Zuber, RES
- 1. Catton, Consultant J. Reyes, RES V. Schrock, Consultant H. Scott, RES H. Sullivan, Consultant N. Lauden, NRR P. Boehnert, Staff M. Fleishman, NRR A complete list of meeting attendees is attached to the Office Copy of these Minutes.
MEETING HIGHLIGHTS, AGREEMENTS, AND REQUESTS
- 1. Mr. Michelson noted the meeting schedule and receipt of the RES Compendium Report on ECCS/LOCA research.
- 2. Dr. L. Shotkin (RES) noted that the ECCS Rule is unique in its proscriptiveness and implementation. Because of the history surrounding this Rule, the revision process has been difficult
- 3. Dr. W. Beckner (RES) discussed the current status of the ECCS Rule revision. RES noted that while there is broad support on the need for Rule revision, there is a wide range of opinions on specific gjoajgg9e60909 DESIC"EED ORIGI RL Certified By /M $
p-T/H Phenomena Meeting Minutes August 28, 1986 details. RES believes the extensive discussion surrounding the Rule has resulted in the sound approach noted below, i The details of the Rule revision were noted (Figures 1 and 2). The key provisions include:
(1) 50.46(a) modified so as to require " realistic" calculations of ECCS performance during a LOCA. In addition, an evaluction of the calculational uncertainty would be required to show that there would be a "high level" of probability that the limits of 50.46(b) would not be exceeded. A provision is also included that gives the Staff the option of derating a plant if the Rule is violated.
(2) As an alternative to the realistic calculations combined with an uncertainty evaluation, tne required and acceptable fea-tures of the current Appendix K would remain available for both current and future evaluation models.
(3) Limits of 50.46(b) would remain unchanged (2200 F PCT - 17%
oxidationlimit).
(4) Re-analysis recuirements are explicitly stated with a larger threshold for reporting changes (50 F) and a reasonable schedule for re-analysis if the plant still meets 50.46(b)
! criteria.
(5) Elimination of historical implementation sections and minor changes to Appendix K.
As a result of CRGR review, a provision will be inserted in the j
Rule to require annual reporting of any minor errors (< 50*F -
Figure 3). Mr. Michelson suggested that if a significant error
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. T/H Phenomena Meeting Minutes August 28, 1986
(> 50"F) is found, all minor errors discovered to that time should be reported as well. Requiring annual versus immediate reporting of minors errors is the only major change in the Rule since the last Subcommittee meeting in April 1986.
The provisions of the Regulatory Guide accompanying the Rule were discussed. Key provisions include:
A 95% probability (two sigma) is acceptable to the Staff to meet the requirement to show with a "... high level of prob-ability that the criteria would not be exceeded." Two sigma meets the probability / confidence requirements.
General guidance on what the Staff would expect to support the 95% probability estimate, but no prescriptive procedure for '
the necessary uncertainty evaluation.
General guidance on what would be expected in realistic models. The basic requirement is to demonstrate the model's comparison to applicable data.
Specific acceptable realistic models and data bases have been removed from the draft regulatory guide and are included in a preface to the guide.
- These models and data bases are subject to change before the draft is published, based on ongoing Staff and Review I Group recommendations. NRC is seeking public comment on l
the need for specific models and data bases in the regulatory guide and on the models and data proposed to i be listed as acceptable.
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= T/H Phenomena Meeting Minutes August 28, 1986 In response to Dr. Catton, Dr. Zuber said that any models used by a Licensee will be required to show applicability to relevant test data, i.e., acceptability of the given model/ correlation must be justified.
Mr. Michelson asked how uncertainties in the BE codes will be addressed. Mr. Ward indicated that the 95% reliability criterion really means one is riding on engineering judgment. Dr. Catton said that the PWR ems don't have as much margin as the BWR EM had prior to its revision a few years back. Dr. Sullivan indicated that the whole issue of uncertainties and their treatment is important and RES should develop a method to derive appropriate limits on uncertainties. RES said NRC (NRR) will review the Licensee's uncertainty analyses, but will not be developing these analyses.
Dr. Sullivan expressed concern that there has been no endorsement of any specific correlations that have been proposed for inclusion in the Regulatory Guide. In particular, the RES-sponsored Experts Panel was generally negative on the proposed correlations. Dr.
Zuber indicated that the Panel focused on the applicability of the data for testing the correlations in question.
The expected effect of the Rule change on plant operation was detailed (Figure 4). It is expected that W plants would benefit most from the Rule change in that 85% of these plants have moderate to strong operational restrictions due to the current ECCS Rule (Figure 5).
The safety impact of the Rule change was analyzed. Overall, RES did not attempt to quantify the net impact. The major downside risk is believed to result from any proposed changes ta plant
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= T/H Phenomena Meeting Minutes August 28, 1986 equipment (e.g.,removeanoperational system,etc.). This type of change is not thought to be a likely result though.
Mr. Michelson asked NRR to determine how the Backfit Rule would impact NRR review of any proposed changes a Licensee wanted to make under the new Rule.
RES showed the schedule for Rule revision and the Regulatory Guide (Figures 6 and 7). The Rule would be issued for public comment in November 1986.
It was noted that RES has stated in a number of places in the Compendium that some phenomena can't be modeled so a sensitivity study (uncertainty analysis) would be done. Dr. Sullivan expressed concern that some of the wording is misleading and may be difficult to defend. RES agreed and solicited ACRS comments on these and other problems with the Compendium.
Regarding SB LOCA concerns, RES said that SB or medium break LOCA may become the limiting break size but RES does not expect any LOCA analyses to become limiting to plant operation.
Mr. Ward said he is bothered by an indefinite grandfathering of the old ECCS Rule. He thinks a time limit of some sort should be imposed so regulation is eventually done on a best-estimate basis in this area. RES indicated that doing a cost benefit on forcing l such a change would be very difficult.
- 4. J. Reyes (RES) discussed the results of the CRGR review of the new ECCS Rule. RES twice met with CRGR on July 23 and August 27, 1986.
As a result of the July 23 Meeting, CRGR raised three issues for RES to address. These issues are:
yu ,o a T/H Phenomena Meeting Minutes August 28, 1986 (1) How elimination of the use of the Dougall-Rohsenow (D-R) film boiling correlation would impact current licensees and how it should be treated vis-a-vis the new BE models.
(2) The need for a requirement that all ECCS code model errors be reported to NRR given that the new Rule specified that any errors resulting in a PCT change of 50*F need not be corrected immediately.
(3) The Director of the Office of Research must determine whether the proposed Rule would result in any decrease in plant safety and result in substantial cost savings for the IndJstry.
For the D-R Issue, RES/NRR proposed that use of D-R in existing ems would be grandfathered. However, if a licensee wished to make any modifications to their existing EM, NRR would have the option of deciding whether or not the D-R correlation should continue to be used. The Staff was told to try to revise their guidance to take account of this. If they could not, they would adopt a " fallback" position that existing EM's would be grandfathered but use of D-R would have to be justified on a case-by-case basis.
l On the issue of error reporting requirements, RES proposed that licensees who had any model errors would only report these on a yearly basis instead of immediately. CRGR agreed with the basic approach and suggested some revisions such as expanding the report-ing of errors to other than PCT (e.g., heat transfer correlation
! results,etc.). Figure 8 details this Item (column labelled
" Option" is the new proposal).
D. Ross (RES Director) made the required determination as noted above. Dr. Sullivan noted that while there may be no decrease in Y
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t T/H Phenomena Meeting Minutes August 28, 1986 safety, the plants will be driven a little harder (closer to the limits). .
O There was extensive discussion of what constitutes an error in the codes versus a deficiency (correlation found inadequate, etc.).
Dr. Zuber said one should differentiate between errors (input errors, model errors, etc.) and deficiencies resulting in how the code is applied to a given plant analysis.
In response to Mr. Michelson's earlier question on the impact of the Backfit Rule, Mr. Lauben indicated that the Staff must show their review decisions were not arbitrary.
- 5. N. Zuber discussed the results and status of the Experts Panel meeting on the acceptability of T/H ccrrelations in the Regulatory Guide. As a result of Subcommittee questions, it was suggested that RES assure that the Compendium Report contains reference to all the correlations specified in the Regulatory Guide. RES agreed to this suggestion.
RES noted NRR's criteria for an " acceptable" correlation (Figure 9). To determine acceptable correlations, RES established an Experts Panel (Figure 10). The Panel split various task assign-ments (Figure 11).
The results of the Panel's deliberations were:
(1) Correlations and models must be checked against an acceptable set of relevant data.
(2) An acceptable set of relevant data should cover thermo-fluid dynamic conditions and geometries pertinent to LWR operations.
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t T/H Phenomena Meeting Minutes August 28, 1986 (3) For the T/H correlation:/models in Regulatory Guide, the experts identified sets of relevant experimental data for assessing correlations /models and listed correlations /models which satisfy above criteria.
In response, RES is: (1) specifying modeling requirements for T/H correlations; (2) identifying sets of acceptable and relevant experimental data; and (3) preparing a list of correlations which meet modeling requirements and have been assessed against relevant experimental data. Figures 12-13 show an example of what will be required for a critical flow model. In response to Dr. Sullivan, Dr. Beckner said RES has not yet decided which models/ correlations will be included in the Regulatory Guide to be issued for public comment in November 1986. Dr. Zuber noted that this new format has not been seen by the Subcommittee before.
RES will submit the new correlations' format to an international Group of experts. This Group will meet during the 14th WRSR Meeting (in October 1986) to discuss the format and coninents. It is hoped to release a set of acceptable and relevant experimental data and correlations with the Regulatory Guide in November 1986.
Dr. Sullivan said RES should assure itself that changes to corre-lations/models and the data base can be readily made as necessary.
Mr. Flieschman said regulatory guides can be readily changed as needed. Dr. Catton said that if a best estimate approach is to be i used, the data base and correlations will constantly change. Dr.
Sullivan noted that the Compendium seems to lean toward a conserva-tive, not a BE, approach. RES agreed and Dr. Zuber said he would discuss how to deal with model/ code uncertainty later in the day.
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yp i T/H Phenomena Meeting Minutes August 28, 1986 H. Scott discussed the decay heat correlation and zircaloy oxida-tion correlations proposed in the Regulatory Guide. Mr. Schrock pointed out a significant error in the Compendium regarding the impact of actinide decay on the overall decay heat rate.
- 6. J. Reyes overviewed the Compendium Report that supports the ECCS Rule revision. The objectives of the Compendium Report include:
(1) provide a " road map" to ECCS research perfomed since the 1974 rulemaking; (2) summarize the principal research related to ECCS performance which supports the use of realistic LOCA analysis in the licensing process; (3) identify ECCS research which demon-strates the overly conservative nature of current Appendix K assumptions; and (4) provide an orderly, well documented, closure of the large break LOCA era.
The Subcommittee made several comments of a general nature regard-ing concerns or problems evidenced in the Report. In response to Mr. Michelson, Dr. Shotkin said RES is developing the methodology to address uncertainties. Mr. Michelson scid the uncertainty associated with test data is not addressed in the Compendium. RES agreed and indicated they would look into this point.
Figure 15 shows the schedule for issuance of the Compendium. It is planned to issue the Report in late October 1986. RES asked for ACRS comments by October 1, 1986. RES will also subject the Report to Expert review in October.
The Subcommittee complemented RES on the overall quality of the Report.
- 7. L. Shotkin addressed the issue of development of methodology for determination of T/H code uncertainty.
,f i T/H Phenomena Meeting Minutes August 28, 1986 In August 1986, RES, LANL and Sandia agreed on an uncertainty methodology which will be submitted to an expert Panel for review.
A NUREG Report is planned for March 1987. LANL and INEL will calculate uncertainty for TRAC-PF1 and RELAP-5/M00-2 respectively in August / September 1987.
RES described the process used to determine code uncertainty (Figures 16-17). Dr. Shotkin said there are four key questions that need to be addressed. These are:
(1) Can 2 [ uncertainty be extrapolated to reactor scale?
(2) How do we ascertain that there is no scaling effect (related to the extrapolation above)?
(3) Is there a chance of compensating errors (related to to extrapolationabove)?
(4) Are differences really random and therefore can they be phrased in statistical tenns?
Figures 18-20 give the RES " response" to the above questions, i.e.,
the actions or approaches RES hopes will resolve the above con-cerns. Dr. Catton raised a concern with the impact of nodilization on the code's extrapolation to full scale. Mr. Schrock noted that the influence of the User and modeling options he chooses (nodili-
, zation) needs to be addressed.
In response to Mr. Michelson, Dr. Shotkin said it is assumed that the phenomenon seen in the experiment is also seen in the full size reactor. RES also indicated that they need to address the variations seen in the individual models of the codes themselves.
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s T/H Phenomena Meeting Minutes August 28, 1986 Dr. Schrock asked how the above methodology will be addressed vis-a-vis the Rulemaking. Dr. Shotkin said the goal is for RES to develop and defend the methodology to their satisfaction. NRR will need to decide whether they want to make use of this methodology.
Mr. Michelson expressed concern with the fact that no one is really developing guidelines to address uncertainty. Dr. Shotkin said RES is tracking the efforts of two of the Vendors in this area and these Vendors will examine RES's efforts in this regard. EPRI is also involved in this effort.
The Chairman said the Subcommittee will want to review this method-ology when its appropriately developed.
- 8. The topic of code scaling capability and the code's applicability to plant safety assessments was detailed by N. Zuber. RES is proposing a method to address code scaling and applicability uncertainty.
There are two parts to the proposed method: (1) transient / accident i
scenario analysis and evaluation, and (2) analysis of code scaling /
applicability (Figure 21).
4 For Item (1) above the procedure proposed is outlined in Figures
, 22-29.
Turning to Item (2) analysis and evaluation of the code scaling and applicability, Dr. Zuber said the four key needs are:
(1) To assess and demonstrate the capability of a particular code, to scale-up processes / phenomena observed in test facilities to conditions relevant to NPP safety studies.
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f s T/H Phenomena Meeting Minutes August 28, 1986 (2) To assess and demonstrate capabilities of a particular code to address:
(a) A particular transient / accident scenario, and/or (b) a set of scenarios for a NPP design.
(3) To identify scenarios which when calculated by a particular code, must be interpreted and accepted with caution.
(4) To identify scenarios which cannot be addressed by the par-ticular code.
The methodology proposed to assess the code's scaling capability is given in Figures 30-31. In order to make use of this method, the code in question must be provided with a: (1) manual,(2) user guide report, (3) QA document, and (4) assessment reports.
Mr. Michelson asked how this method would provide an uncertainty evaluation for the code. Dr. Zuber said a sensitivity analysis of the closure equations will provide the uncertainty. Dr. Catton agreed.
RES is requiring development of a QA Report for each advanced T/H code by the respective developer (National Laboratory). Figures 32-35 provide the details.
The diagnostic analysis to be applied to the code's field and closure equations were discussed (Figures 36-37). A schematic of the analysis process is shown on Figure 38. The closure equation analysis will demonstrate whether or not the given code can scale up to a full size plant. The diagnostic analysis also provides a ranking of the ability of a given code to scale up to a full size plant.
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s T/H Phenomena Meeting Minutes August 28, 1986 Combining the results of the transient / accident evaluation (Figure
- 27) with the results of the scaling / applicability evaluation will allow a comparison of the overall capability of the code (Figure 39).
In response to Mr. Michelson, Dr. Zuber said a NUREG detailing this overall process will be published in December 1986.
RES solicited ACRS comments on the above approach. Dr. Sullivan said he thought the approach is workable and the " proof will be in the pudding."
- 9. Mr. Michelson asked if any Consultants had any suggestions for major issues that should be addressed at the full Committee meeting in September. Dr. Catton said the three d,ocuments (Rule, Regula-tory Guide and Compendium) should be consi' stent if they refer to each other. The Regulatory Guide should refer to acceptable methods to be used by Licensees. He believes Dr. Zuber's approach is feasible and seems to be the only one that will give the desired results vis-a-vis the questicn of dealing with uncertainties.
Dr. Sullivan concurred with the uncertainty concern. With a BE approach, there is no " anchor" on the uncertainty analysis. This analysis may be beyond the capability or prudent expense of the Licensees. The objectives and content of the Regulatory Guide and Compendium are not clear nor do they form a basis for firm support of Rulemaking. He is concerned with issuing these documents in their present form for public comment. Scaling is a significant issue. Dr. Zuber's approach will help, but the issue is still open in his mind. The Regulatory Guide is not supportive of the Compen-dium and some inconsistencies are evident. The Compendium does not
- support going to a BE analysis and probabily should be revised to l Qu so. t l
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s T/H Phenomena Meeting Minutes August 28, 1986 Mr. Ward said he doesn't believe the current Rule should be grand-fathered indefinitely.
Dr. Sullivan suggested RES try to use the new Rule procedure vis-a-vis an advanced code to see if there are any flaws that need to be addressed and to assure that the process is workable. RES agreed this would be a worthwhile exercise.
The Chairman requested two written reports from the Consultants:
(1) a Report that identifies any key issues the Committee should address during its review at the September Meeting; and (2) a Report in ad one month's time that provides more detailed comments on the Rule Documents - particularly the Compendium Report.
- 10. Prior to adjournment, the Subcommittee Chairman noted that time has been allotted to bring this issue to the ACRS at its September Meeting. He discussed the particulars of the expected discussion topics for the full Committee meeting.
- 11. The meeting was adjourned at 5:06 p.m.
NOTE: Additional meeting details can be obtained from a transcript of this meeting available in the NRC Public Document Room, 1717 H Street, N.W. Washington, DC, or can be purchased from ACE-Federal Reporters, 444 North Capitol Street, Washington, DC 20001, (202) 347-3700.
a
PROPOSED RULE EVISION 50.46(A)(1)
(1)
... ANALYTICAL TECmIQUE EALISTICALLY DESCRIBES TE BEHAV "COPPARISONS TO APPLICABLE EXPERI E NTAL DATA..."
"lECERTAINTY MJST BE ACCOUNTED FOR SO THAT... TEE IS (PARAGRAPH B1 WOULD NOT BE EXCEEDED."
K..."
(11) " ALTERNATIVELY, AN ECCS EVALUATION P0 DEL MAY BE DEVELOPED IN CO 50.46(A)(2)
"ESTRICTIONS ON REACTOR OPERATION WILL BE IIPOSED...IF SUBMITTED AE NOT CONSISTENT WITH PARAGRAPHS (A)(1)(I)
EALTH AND SAFETY "
50.46(A)(3)
... ESTIMATE TE EFFECT OF ANY CHANGE TO OR ERROR IN AN A E THAN 50*F. . ."
...SIGNIFICANT CHANGE OR ERROR IS DE WHICH ESULTS IN...TEP "FOR EACH SIGPlIFICANT CHANGE TO, OR ANY ERROR"...EPORT TE NAlt'RE O ESTIMATED EFFECT ON TE LIMITING ECCS ANALYSIS
' ** EPORTING OF MINOR ERRORS SUBJECT TO CHANGE l v _ _ - - _ _ _ _ _ _ _ - .
.i s
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...EPORT A PRDFOSED SCKDULE."
YSTEM, A SCEDULE FOR ACHIEVING
... FACILITIES NOT HAVING NRC APPROVED INTEGRATED SC DUL l
C&FLIANCE WILL BE ESTABLISHED BY THE NRC STAFF WITHIN 6 FORTABLE "ANY CHANGE OR ERROR...DOES NOT C0 FORM TO C EVENT AS DESCRIBED IN 50.72 AM) 50.73."
1 APPEM)IX K EENCE UPDATED. "
i 1.C.5.B - DOUGALL-ROHSENOW C0 RELATION REPOVE II - CHANGES IN DOCTENTATION EQUIREPENTS T0:
- 1. REPUVE 20*F DEFINITION OF SIGNIFICANT CHANGE
- 2. PROVIDE A COPPLETE LISTING 0F COPFUTER PROGRfM
- 3. mal (E CONSISTENT WITH CHANGES IN 50.16(A).
PROBLEM 0F EXISTING MODELS USING D-R UEER DISCUSSION 1 .
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II. FOR EACH ORNGE TO, OR ANY ERROR DISCOEED IN, AN ACCEPTABLE EVALUATION P0 DEL WHICH AFFECTS TE TEITERATUE CALCULATION, TIE APPLICANT OR LICENSEE SHALL EPORT TE NATUE OF TE CHANGE OR
. ERROR AND ITS ESTIMATED EFFECT ON TE LIMITING ECCS ANALYSIS TO TtE C0rtilSSION AT LEAST ANNUALLY AS SPECIFIED IN S50.4. IF TIE OMNGE OR ERROR IS SIGNIFICANT EACH APPLICANT OR LICENSEE SHALL PROVII THIS EPORT WITHIN 30 DAYS AND ALSO INCLll)E WITH TE REPORT A PROPOSED SOEDULE FOR C0FFLETING ACTIONS NEEDED TO COPFLY WITH APPLICABLE EQUIRENNTS. THIS SCEDULE MAY BE DEVELOPED USING AN INTEGRATED SOEDULING SYSTEM PREVIOUSLY APPROVED FOR TE FACILITY BY TE NRC. FOR THOSE FACILITIES NOT USING AN NRC APPROVED INTEGRATED SOEDULING SYSTEM, A SOEDULE FOR AallEVING C0FFLIANCE WILL BE ESTABLISHED BY TIE NRC STAFF WITHIN 60 DAYS OF ECEIPT OF TE PP0 POSED SOEDULE. ANY CHANGE OR ERROR CORECTION THAT ESULTS IN A CALCULATED ECCS COOLING PERF0lFANCE TilAT DOES NOT CONFORM TO TIE CRITERIA SET FORTH IN PARAGPAPH (B) 0F THIS SECTION IS A EPORTABLE EVENT AS DESCRIBED IN S50.55(E), 550.72 AND 550.73. THE AFFECTED APPLICANT OR LICENSEE SHALL PROPOSE litEDIATE STEPS TO DEMONSTRATE C0FFLIANCE OR BRING PLANT DESIGN OR OPERATION INTO C0FFLIANCE, i
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EGlLATORY ANALYSIS-EFFECT OF RULE _ CHANGE _
- CALCULATED PEAK CLADDING ItITERATllRES (PCT) DURING LA WOULD BE REDUCED. AM)UNT OF REDUCTION WOULD E PLAhT HOWEVER, TE REDUCTION IN CALCtLATED PCT WOULD LIITLY BE LARGE EN TE CALCULATION.
LARGE LOCA CONSIDERATIONS WOULD NO LONGER BE LIMITING. OTER CONS WOULD LIMIT PLANT OPERATION.
SMALL BREAK LOCA (SBLOCA) M)DELS AE GEERALLY M)RE EALI BE LESS AttELitu BY TE PROPOSED RULE CHANGE, SBLOCA MAY BEC0E LIMITING.
REDUCED CALCULATED LARGE BEAK LOCA PCT COULD ESULT IN:
INCREASED ALLOWED PEAK LOCAL POWER INCREASED TOTAL POWER
- CHANGES IN EQUIPENT, SURVEILLANCE OR LCO i
ALL TE ABUE CHANGES WOULD LIIELY NOT BE POSSIBLE AT TE j WOULD HAVE TO BE CONSIDEED SUCH AS:
- DNB LIMITS PLANT HARDWAE LIMITS OTER CHAPTER 15 EVENTS s
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LOCA LIMITS ON WESTINGHOUSE PLANTS
- CURRENT TEGNICAL SECIFICATIONS AE UPDATED FSAR'S INDICATED THAT:
15% OF W PLANTS AE NOT RESTRICTED BY APPEElX0 K LOCA CRITERIA (F = 2.32; LIMITING LBLOCAPCTg2000*F) 41% HAVE NDERATE OPERATIONAL RESTRICTIONS LIMITATIONS ON LOAD FOLLOWING
- LIMITATIONS ON STEAM GEERATOR TUBE 0 PLUGGING (F = 2.R; LIMITIE N PCT 7 2000*F)
- 44% HAVE STRONG OPERATIONAL RESTRICTIONS LIMITATIONS AS ABOVE INCEASED CORE MONITORING EC8JIREENTS POSSIBLE DIFFICULTIES IN ACHIEVING FULL POWER
(GENERALLY F0
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v SCKDULE FOR REVISION OF ECCS RULE APRIL 1986 ACRS METING TO UPDATE ECCS RULE ACTIVITIES JtNE 1986
- NRR, DRR, ELD, RES CONCUR WITH PROPOSED RULE JULY 1986 CRGR PEETING AUGUST 1986 ED0/CRGR N ETING SEFIDBER 1986 C0PMISSION NOVEPEER 1986 NOTICE OF PROPOSED RULEMAKING ISSUED FOR PUBLIC COPPENT FEBRUARY 1987 COP E NT ERIOD ENDS NOVEPEER 1987 FINAL RULE PUBLISED u .
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SO EXLE FOR PREPARATION AE PUBLICATION OF REGlLATORY GUIDE FOR EALISTIC ECCS ANALYSES APRIL 1986 U.S. EXPERTS EVIEW 0F TERM-HYDRAULIC P00ELS BEGINS JUNE 1986 NRR REVIEW OF DRAFT EGILATORY GUIDE COPPLETED JtLY 1986 PELIMINARY ESULTS OF U.S. EXPERT EVIEW OCTOBER 1986 RES SELECTS MDDELS AE DATA BASE FOR DRAFT EGULATORY GUIDE FO NOVEN ER 1986 DRAFT EGULATORY GUIDE ISSIED FOR PUBLIC C0WENT FEBRUARY 1987 PUBLIC C0WENT PERIOD ENDS Jlh'E 1987 FINAL FUEL PHENDENA MODELS SELECTED JULY 1987 FINAL U.S. EXPERTS ECOWENDATIONS FOR TERfD-HYDRAlLIC P0DELS OCTOBER 1987 RES SELECTS FINAL P0DELS AND DATA BASE NOVEPBER 1987 FINAL EGlLATORY GUIDE ISSUED
o
- 2. !!HETING_E311REFEJLTS ~
TABLE OF CURRENT AM) PROPOSED ECCS RULE
_ERJRIIN(i R HEUUlHtftNIS (50.46 AND AHtNDIX K)
OPTION PROPOSED ECCS RULE CURRENT ECCS RULE AS WR1IIEN_ AS IITLtK NTED
- 1. PROVIDE AMUAL
- 1. ALL ERRORS REPORTED NDEL NOT ADDRESSED 1. ALL ERRORS REPORTED. SlfEARY REPORT OF
- 2. LEGAL INTERPETATION RR 50.4 ERRORS: ALL PDDEL CHANGES 0F 50.46 (A) (1) EANS 2. EANALYSIS FOR ERRORS >50*F.
AND ERRORS.
LICENSEE IS IN 3. SUBMIT SCHEDULES FOR EANALYSIS.
(SIMILAR TO 50.59)
NONCONFORMANCE IF 4. ALL_ ERRORS EXCEEDING 50.46 (B)
CRITERIA REPORTED RR 50.55E, 2. CHANGES AND ERRORS MODEL ERRORS EXIST. >50*F REPORTED PER 50.72 AND 50.73.
- 3. INTERIM PENALTIES IF 50.4.
50.46(B) IS EXCEEDCD. 3. EANALYSIS FOR CHANGES AND ERRORS >50 *F.
- 4. SUBMIT SCHEDULE FOR EANALYSIS,
- 5. ALL CHANGES AND tRRORS EXCEEDING 50.46(B)
CRITERIA REPORTED PER 50.55(E), 50.72 AE 50.73.
- 1. ALL CHANGES REPORTED. 1. ALL CHANGES >50*F EPORTED ER 50.4 F0 DEL ALL CHANGES CHANGES: > 20*F AE 2. EANALYSIS FOR CHANGES 2. EANALYSIS FOR CHANGES >50*F.
> 20* F . 3. SUBMIT SCHEDULE FCR REANALYSIS.
REPORTED.
- 3. NRC LETTER DICTATES
- 4. ALL CHANGES EXCEEDING 50.46 (B)
CRITERIA EPORTED PER 50.55E, ,
SCHEDULE AM) DETAILED 50.72, AM) 50.73.
r REPORTING EQUIEENTS.
hI N
8 l _ _ _ _ _ - _ - _ _ _ _ _ _ _
4 NRR's CRITERIA FOR AN " ACCEPTABLE" CONI @
- 1. TE ES FINDING OF ACCEPTABILITY FOR TE SRCIFIED C0 RELATIONS AE NDE WITH ANY STATEENTS OR CONCLUSIONS COITTAINED IN TE RtrtHENCES USED T ACCEPTABILITY, AND THAT SUCH A REVIEW HAS BEEN MADE. KNOWN CONFLICTS HAVE BEEN REVIE AND TE ES POSITION IS DEFEl0ABLE.
- 2. TEE AE NO KNOWN DISAGREEENTS WITH TE ES CONCLUSION OF ACCEPTABILI ESEARCERS OR EXPERTS, EITER PUBLISHED OR OTERWISE. ANY DISAGREEENTS THAT AE KNOW TO EXIST HAVE BEEN THOROUGHLY EVIENED BY ES AND ES IS PEPAED TO DE
- 3. TE CORRELATIONS OR MODELS PROPOSED TO BE TERED ACCEPTABLE AE NOT OTER APPLICABLE DATA, C0 RELATIONS, OR NDELS, A.'O THAT SUCH A REVIEW HAS BEEN MADE.
KNOWN DISAGREEENTS AE EXPLAINABLE.
I a
EXRRTS ON THERMD-HYDRAULIC C0 RELATIONS DR. D. DlFFEY ELECTRIC POWER RESEARCH INSTITIITE P. O. BOX 10412 PALO ALTO, CALIFORNIA 94303 PROFESSOR P. GRIFFITH MASSACHUSETTS INSTITUTE OF TE0fl0 LOGY DEPARTENT OF ECHANICAL ENGINEERING 77 MASSACHUSETTS AVENUE CAMBRIDGE, MASSACHUSETTS 02139 DR. G. F. HEWITT HARWELL ESEARCH ESTABLISTENT HARWELL,ABINGTON ENGLAND DR. S. LEW SOL LEW INCORPORATFD 1999 SOUTH BASCOM AVENUE CAffBELL, CALIFORNIA 95008 PROFESSOR H. RICHTER DARMOUTH COLLEGE HANNOVER, NEW HAffSHIE NOVAK ZUBER EACTOR SYSTEMS BRANCH DIVISION OF EACTOR SYSTEMS SAFETY m
)
TASK ASSIGNTNTS ASSIGNTNTS' TASK PRIMARY SEC0 WARY P. GRIFFITH R. DUFFEY
- 1. POST CHF HEAT TRANSFER l
N. ZUBER S. LEW
- 2. LEVEL SWELL R. DUFFEY P. GRIFFITH
- 3. UNCOVERED BUNDLE HEAT TRANSFER H. RICHTER N. ZUBER 14 . ECC BYPASS G. HEWITT S. LEW
- 5. FRICTIONAL PRESSURE DROP G. HEWITT R. DUFFEY
- 6. CHF S. LEW H. RICHTER
- 7. CRITICAL FLOW h
D.
o Critical Flow Critical flow models to be employed in ECCS evaluations must:
- be checked against an acceptable set of relevant data recognize themal non-equilibrium conditions when fluid is subcooled provide a means of transition form non-equilibrium to equilibrium conditions An acceptable set of relevant critical flow data should cover the fluid conditions, geometries, types of breaks pertinent to light water reactor loss of coolant accidents.
The following tests should be considered in establishing an acceptable set of relevant data:
Marviken tests (1)
Moby Dick Experiments L2)
BNL Critical Flashing Flows in Nozzles M)
Sozzi-Sutherland tests H)
Edwards experiments L5)
Super Moby Dick Experiments g)
The mechanistic thermal non-equilibrium and slip model of Richter (7) provides acceptable results when compared to small and large scale test data (8)
For critical flow from small breaks under stratified conditions, currently acceptalbe test data for assessing models and/or codes include those reported by:
Anderson and Owca (8)
Reimann and Khan (10)
Schrock et al (11)
REFERENCES
~
- 1. "Marviken Full Scale Critical Flow Tests, Summary Report." Joint Reactor Safety Experiments in the Marviken Power Station, Sweden, NUREG/CR-2671, 1982.
- 2. Reocreux, M., " Contribution a l' etude des debits critiques en enoulement diphasique eau-vareur," Ph. D. Thesis, L'Universite Scientifique Medicale de Grenoble, 1974.
e j
- 3. Abuaf N., et al., "A Study of Nonequilibrium Flashing of Water in a Converging - Diverging Nozzle," NUREG/CR-1864, BNL-NUREG-51317, 1981.
- 4. Sozzi, G. L., W. A. Sutherland, " Critical Flow of Saturated and Subcooled Water at High Pressure," GE Report NED0-13418, 1975.
- 5. Edwards, A. R., T. P. O'Brien, " Studies of Phenomena Connected with the Depressurization of Water Reactors," J. British Nuclear Energy Society, Vol. 9. No. 2, April 1970.
- 6. Jeandey, Ch., et al., " Auto vaporization d'ecoulements eau /vapeur" Rapport TT, No 163, Centre d' Etudes Nucleaires de Grenoble, Grenoble, France Juillet 1981.
- 7. Richter, H. J. " Separated Flow Model: Application to Critical Flow " EPRI Report NP-1800, April 1981.
- 8. Abdollahian, D., et al, " Critical Flow Data Review and Analysis," EPRI Report NP 2192 January 1982.
- 9. Anderson, J. L. and Owca, W. A., " Data Report for the TPFL Tee / Critical Flow Experiments," NUREG/CR-164, June 1985.
- 10. Reimann, J. and Khan, M., " Flow Through a Small Break at the Top of a Large Pipe with Staratified Flow", Nuclear Science and Engineering, Vol 88, pp. 297-310, 1984.
- 11. Schrock, V. E., et al., " Steam-Water Critical Flow Through Small Pips From Stratified Upsteam Regious" Proc. 8th International Heat Transfer Conference, San Francisco. August 18-22, 1986.
yll.lh
SUGGESTED AEAS FOR ACRS C0ffENT ON ECCS ESEARCH COPPENDIU 1.
REVIEW OVESTIONS IN CHAPTER IV FOR IFFORTANCE, KRTINENCE, FOCUS, (DEL
- 2. IDENTIFY ADDITIONAL REFERENCES
- 3. ' CONSIDER UNIFORMITY OF LEVEL OF DETAIL 11 . CONSIDER PROS & CONS OF SIZE OF REPORT N '
- \ 3
6 e
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SCEDULE FOR PREPARATION AIO PUBLICATION OF "00PPENDilN OF ECCS RESEAR01 FOR REALISTIC LOCA ANALYSIS" APRIL 1986 ROUGH DRAFT 00PPLETED APRIL 1986 INEL REVIEW BEGINS JULY 1986 INEL EVIEW COPPLETED AUGUST 1986 RES EDITING COPPLETED OCTOER 1986 DRAFT ISSUED FOR PUBLIC C0ftENT OCTOBER 1986 EXTERNAL EXPERT REVIEW BEGINS FEBRUARY 1987 PUBLIC C0ffENT PERIOD AND EXTERNAL EXRRT EVIEW COPPLETE OCTOBER 1987 RES REVIEW / EDITING COPPLETE NDVEPEER 1987 FINAL EPORT PUBLISHED
CODE UNCERTAINTY
- SOURCES AE NDELS, CORRELATIONS, NLPERICS, SCALING, N00ALIZATION AE OTER USER EFFECTS UNCERTAINIY FOR A 1(EY PARAETER IS DETERMINED BY COIPARING EXPERIENTAL AND CALCULATED VALUES
- QUALITATIVE ANALYSIS OF TRENDS, MllCH MIGHT BE MISSED BY JUST QUANTITATIVELY ANALYZING BIASES, IS ALSO EQUIRED UNCERTAINIY STATEENTS CAN BE APPLIED TO DIFFERENT SEGENTS OF TRANSIENT IN WHICH DIFFERENT PHENDENA AE DOMINANT
-** DEFINE PORTIONS OF TRANSIENT BY GOVERNING PHENOW NA LBLOCA CAN BE DIVIDED INTO:
- BLOWDOWN (BEF0E ACCIMJLATOR INJECTION)
REFLOOD (AFTER ACClMJLATOR INJECTION)
PERF0Wi ANALYSIS DURING TIE EGIONS- IN WHICH TE SAE PHENDENA OCCUR FOR BOTH TE EXPERIENT AND CALCULATION vs 3
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O CODE UNCERTAINTY (CONT)
E FORM DIFFEENCES FOR LEY PARAETERS FOR A SRCIFIC NODE BEINEEN CODE CALCULATIO EXERIENTAL DATA. DIFFERENCES CAN BE FOR A SINGLE PARAETER (SU0i AS TE PEAK CLAD TUPERATUE) OR FOR AN AVERAGED PARAEER FOR TilAT TIE EGION (SUCH AS TE AVERAGE CLAD TUlPERATUE FROM TIE OF CHF TO TIE OF PCT).
WE EPEAT SIMILAR CALCULATIONS FOR OT11ER TRANSIENTS IN TE SAE CLASS IN TE SAE FACILITY (SUCH AS LBLOCA AT DIFFERENT POWER LEVELS OR PLPP TRIPS-PROVIDED PHEN 0KNA AE TE SAE IN 111E EGION) .
TRANSIENTS IN TE SAE CLASS BUT DIFFERENT FACILITIES OF DIFFERENT SCALES PLOT TE DIFFERENCES VS. SCALE 4
m
TO ANSWER TE FIRST TWO QLESTIONS E ASStPE THAT IF DISTRIBUTION OF DIFFERENCES IS APPR0XIMATEl.
UNIF0m, TEE IS NO SCALING EFFECT A SCALING EFFECT IS ILLUSTRATED
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' SCALE TE E)GRAPOLATION TO EACTOR SCALE CAlW0T E MADE WITH COWIDENCE. IF TERE IS A SCALING EFRCT, TE CODE NEEDS INROVEPENT. TE CODE IS A SCALING TOOL. IT SHOULD PREDICT EXPERIENTAL TESTS IN FACILITIES AS ELL AS TRANSIENTS IN REACTORS N
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IN ORDER TO ADDESS THE 3RD OUESTION DEALING WITH COPPENSATING ERRORS W SEVERAL KEY PARAKTERS, AND NOT JUST TCLAD' l
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TO ANSWER TE LAST GUESTION WE EED TO D80NSTRATE THAT TESE DI NOR%LLY DISTRIBUTED IN ORDER TO MAE COWIDENCE AE TOLERANCE STATEENT PLOT HISTOGRAMS FOR ALL POINTS TO ILLUSTRATE TE DISTRIBlITION FetEQ0GelC4
. A i GiA5 E NEED AT LEAST 30 POINTS TO FORM A EANINGFUL HISTOGRAM DIFFERENCES EXPtuw TO FORM NORMALLY DISTDIBUTED POPULATION RAND 0PNESS INTRODUCED BY STATISTICALLY BASED CDRRELATIONS DIFFERENT NODAllZATIONS SHOULD INTRODUCE RAND 0PNESS MODELING DEFICIENCIES SHOULD PRODUCE A BIAS AS INDICATED IN TE FIGUE 9
W - _ . -__ - _
PROPOSED ETH00 TE PROPOSED ETHOD CONSISTS OF TWO ACTIVITIES:
TRANSIENT / ACCIDENT SCENARIOS ANALYSIS AND EVALUATION IDENTIFIES AND EVALUATES: ,
SCENARIOS OF INitxtsi TO A NPP SAFETY ASSESSENT EQUIREENTS TO PODEL ABOVE SCENARIOS ESULTS CAN BE APPLIED TO ALL CODES 1 P CODE SCALING / APPLICABILITY ANALYSIS AND EVALUATION EVALUATES /DEM)NSTRATES CODE CAPABILITY T0:
EET P0DELING EQUIREENTS FOR SCENARIOS SCALE-UP PROCESSES FROM TEST FACILITY TO NPP i PERFORM EFFICIENT AND ELIABLE CALCULATIONS PRODUCE ESULTS OF DESIRED ACCURACY PE.TORM NPP CALCULATIONS BASED ON A RATIONAL NODALIZATION SCHEK IDENTIFIES SCENARIOS WHICH:
MAY EQUIE SENSITIVITY STUDIES l
i CAltl0T BE ADDESSED BY TE CODE ESULTS AE VALID FOR A PARTICULAR CODE w i l
TPANSIENT/ ACCIDENT .
SCENARIOS ANALYSIS AND EVAltIATI0f!
l _ PROCEDURE:
ENGINEERING JUDGEE NT PPA STl0lES EXPERIENCE AND KNOWLEDGE BASED ON EXPERIE NTS AND/0R ANALYSES PLANT OPERATION HISTORY
- 2. FOR EACH SCENARIO OF THE GIVEN SET:
A. PERFORM AN ANALYSIS TO DEVELOP A PROCESS / PHENOMENA IDENEIFICATION TABLE FOR EACH C0F OF TIE SYSTEM B. EVALUATE AIO RANK ABOVE PROCESSES /PHENDENA TO GENERATE:
PROCESS /RENDENA RANKING TABLE FOR EACH C0FFONENT PROCESS / PHENOMENA RANKING TABLE FOR GIVEN SCENARIO
- 3. SYNTHESIZE RESULTS OF ITEM 7 ABOVE TO GENERATE TABLE (, THAT RANKS PROCESSES /PIEN0KNA FOR THE SELECTED SET OF SCENARIOS l
hE/04/86
TPANSIENT/ ACCIDENT SCEFARIOS ANALYSIS AND EVAltfATION v
SCENARIOS SET SELECTION
+
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SCENARIO ' SCENARIO SCENARIO B Z A
- 4 [
ANALYSIS TABLE A-1: PROCESS /FHENDENA IDENTIFICATION FOR C0lT0NENTS 4
EVALUATION TABLE A-2: PROCESS /PENTENA RANKING FOR C0FFONENTS TABLE A-3: PROCESS / PHENOMENA RANKING FOR SCENARIO A y d N TABLE (: PROCESS /PilEN0K NA RANKING FOR SCENARIOS SET I
06 /Oli/86 e
p, SCENARIO A ANALYSIS PURPOSE: l
- 1. TO IDENTIFY AND TRACE RELEVANT PROCESSES AND ROUENA AS TIEY EVOLVE THROUGH0lfT THE SYSTEM I
- 2. TO GENERATE TIE PROCESSES /PHENDE NA IDENTIFICATION TABLE FOR GIVEN SCENARIO i
ETHODOLOGY:
THE ANALYSIS SHOULD BE BASED ON/ GUIDED BY:
EXPERIENTAL TEST RESILTS PLANT DATA CODE CALCULATIONS AND/0R COT UCTED BY PERFORMING A "GEDANKEN" TRANSIENT OR ACCIDENT m
/04/86
PROCEDURE:
10 DIVIDE SELECTED SCENARIO (SAY SCENARIO A) IN TIE INTERVALS / SNAPSHOTS, L FOR EACH SNAPSiOT IDENTIFY AND RELATE PROCESSFS/PliEN0TNA AS TEY OCCllR IN EACH COPPONENT FOLLOWING CLOSED CIRCUITS Tl1 ROUGH VESSEL, LOOPS AND SG'S I
- 3. IDENTIFY AND RELATE CAUSE AND EFFECTS II . REPEAT APINE PROCEDURE FROM SNAPSHOT TO SNAPSIOT LWTIL TIE END OF SCENARIO A
- 5. GENERATE TABLE A-1, WHICH IDENTIFIES PROCESSES AND PHENOPENA IN EACH COPFONENT
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io" YABLEA-1: PROCESSES /RENOWNA IDENTIFICATION
- s. y e C0lPONENT cl C(PFONENT A COPONENT Y TI E INTERVAL
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PROCESS /RENOWNA Y AI, PROCESS /ROUGA X Y
A rt 4 AI, .
1 3 C0rMNTS ON TABLE A-1
- 1. THIS TABLE IS USEFUL FOR:
A. ACCOUNTING OF PROCESSES AND PHENORNA 1
B. DEVELOPING A FEEL FOR TIE RELEVANT RNSICS OF TIE SCENARIO C. FOCUSING ON THE TIMING AND RELEVANCE OF VARI 0lS PROCESSES AND D. ASSESSING THE CONSISTENCY OF CALCULATED RESULTS E. ASSESSING T}E OVERALL ROLE OF A GIVEN C0ff0NENT IN TIE EVOLUTION O he -
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PROCED_t1RE: [Ek#l/Milw]
- 1. FOR EA01 COMPONENT SlKMI IN TABLE A-1 EVALUATE TIE It1VRTANCE OF PROCESSES /RDOUIA Wil01 H BEEN IDENTIFIED TO OCCUR IXJRING TIE EPITIRE SCENARIO 2, llSING A SCALE SAY FPOM ONE TO FIVE GFFFRATE TABLE A-2, WHIOl RANKS PROCESSES /RENOMENA F0P FAOf COPPONENT TAPLE A-2: PROCESSFS/RDl0FENA RANKlf0 FDP COMPONENTS I
C0r10NENT l t RANK C0FFONENT 4 C0FFONENT ['
PROCESS /R B O U Ay PP0 CESS / PHEN 0rOA 5 PROCESS /RIEN09Ay T
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- 3. USING RANKINGS SHOWN IN TAPLE A-2, GENEPATE TABLE A-3, MIICH RANKS THE IPFORTANCE OF VAPIOUS PROCESSES /PHENTENA OR ISSIES M'D/0R RESULTS ASSOCIATED WITH SCENARIO A.
TABLE A-3: PROCESS / PHEN 0 PENA PANKING FOR SCENARIO A .
PROCESS /PHENTENA 3 RANK PROCESS /RENTENA )( PROCESS /REN0 PENA $
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COM U TS CONCERNING TAR E A-3 FOR A GIVEN SCENARIO THIS TABLE CAN BE USED TO:
- 1. ESTABLISH THE ELATIVE IPPORTANCE OF VARIOUS PROCESSES AND PHENOPDIA
FOR EXAPPLE, IF A SCENARIO IS VERY SENSITIVE TO MANY PROCESSES /PHENOMCNA, TilAT IS, TEE AE MANY PROCESSES /PHENOPENA 0F RANK 5, TEN THIS SCENARIO IS MDRE COMPLEX AND MORE DIFFICULT TO CALC (LATE
, THAN A SCENARIO WilCH HAS ONLY ONE OR TM) PROCESSES /PHENOPENA 0F RANK 5
- 3. EVALUATE THE CAPABILITY OF A CODE TO CALCILATE TIE PARTIClLAR SCENARIO
- 4. ESTABLISH PRIORITIES FOR CODE IPPROVENNTS IF NEEDED TO ADDESS TE e
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o ETH000 LOGY T K KTHOD IS BASED ON THREE ELEE NTS:
]. CODE DOCtfENTATION
- 2. ANALYSIS OF CODE P0DELING/ SCALING CAPABILITIES AS PROVIDED BY:
A. FIELD E00ATIONS B. CLOSURE EQUATIONS
- 3. EVALUATION OF CODE ASSESSE NT CALCULATIONS OF:
l A. SEPARATE EFFECT TESTS B. INTEGRAL EFFECT TESTS AND A SYNTESIS b2
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/06/86
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CODE APPLICABILITT .
ANALYSISANDEVAl#RifW FR&l FROM CODE PANK TABLES PANK TABLES MNUAL USER GUIDE
- OA REPORT ASSESSENT HutmS -
,, n u o EVALUATION ANALYSIS -
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SEPARATE EFFECT INTEGRAL EFFECT CLOSURE FIELD TESTS TESTS EQUATIONS EQUATIONS l
I o J o r SYNTHESISi MDDELING/ SCALING APPLICATION ASSESSPENT CODE APPLICABILITY DOCUPENT k..
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ORIECTIVES APO PEGliPEPUTS r
OPJECTIVES TIE DA IRIENT HAS TilPEE ORIECTIVES:
- 1. TO PROVIN ETAILED INF0f0AT10N ON (TTE 00AllTY OF) CLOStE EQUATintS, T12AT IS, ON CORRELATION P0DELS AND/0R CRITERIA ISED IN TIE CODE
- 2. TO DESCRIK HOW TESE CLOSl!E RELATI0tG APE CODED IN TE PROGRN1 AFD ASSUE TilAT M1AT IS LISTED IN.C0K MANUAL IS INDEED M1AT TIE CODE USES
- 3. TO PPOVIDE A TEONICAL PATIONAL AND JtSTIFICATION FOR USING llESE CLOSIE KLATI0f6 (AS CODED IN TE PPOGPAM) IN TIE RANGE OF IIITEPEST TO NFT) SAFETY EVALUATIONS E0JIPENNIS FOR EA01 CORRELATI0fS, MPDFL, CRITERION OR CONSTANT USED IN CODE CALCULATIONS,11E DA DOCUENT FIGT
- 1. PROVIT IPFORMATION Ot!:
A. ITS ORIGINAL S0llRCE w
B. ITS DATA RASE .
C. ITS ACCllRACY D. ITS APPLICABilllY TO NPP CONDITIONS ,
- 2. PROVIDE AN ASSESSiiNT OF EFFECTS, IF IT IS USED OUTSIE DATA BASE
- 4. DESCRIBE ANY E DIFICATION RE0lllRED TO OVERC04 C0lPUTAT!0NAL DIFFICULTIES
- 5. PROVIDE AN ASSESSENT OF EFFECTS DlE TO llPLUENTATION (ITD13) AND/0R DUE TO ITDIFICAT (ITEM 4) ON CODE OVERALL APPLICABILITY AND ACCURACY N'
k
- Q 06/06/86
. j '1 EQUIRDFNTS FOR CODE ASSESSTNT NtmHis .
TO GAIN CONFIDENCE IN THE PREDICTIVE CAPABILITY OF A CODE, IT IS NECESSARY:
- 1. TO ASSESS THE CAPABILITY OF A CODE TO CALCULATE WITH REASONABLE ACCURACY, TK PMGNITUDES bF VARIOUS PARAK TERS SUCH AS: CLAD TEMPERATURE, INLET AND OUTLET FLOWS FOR VARIOUS COPPONENTS, l PRESSURE DROPS, LIQUID INVENTORY DISTRIBUTION, TEMPERATURE DISTRIBUTIONS, ETC.,
- 2. TO DETERMINE WHETTER OR NOT THE CALCULATED RESULTS ARE DUE TO COMPENSATING ERRORS,
- 3. TO ASSESS WHETER OR NOT TE CALCULATED RESULTS ARE SELF-CONSISTENT AND PRESENT A COHESIVE SET OF INFORMATION THAT IS TECHNICALLY RATIONAL AND ACCEPTABLE,
- 4. TO ASSESS WHETlER OR NOT THE TIMING OF EVENTS CALCULATED BY A CODE ARE' IN AGREENNT WITH EXPERlW NTAL DATA, AND
- 5. TO EXPLAIN ANY UNEXPECTED OR AT FIRST GLANCE, STRANGE RESULT CALCULATED BY THE CODE. THIS IS PARTICULARLY IMPORTANT WHEN EXPERIE NTAL K ASUREN NTS ARE NOT AVAILABLE TO GIVE CREDENCE TO CALCULATED RESULTS. lH SUCH CASES, RATIONAL TECHNICAL EXPLANATIONS WILL GO A VERY LONG WAY TOWARDS GENERATING CREDIBILITY AND CONFIDENCE IN THE CODE.
~
kO6/06/86
60 l l
FUTHERMORE, WHEP'EVER THERE IS A DISAGREEKNT BETWEEN CALCULATED RESULTS AND EXPERIENTAL D .
I NECESSARY: l l
- 6. TO IDENTIFY AN EXPLAIN TE CAUSF FOR DISCREPANCY, T mT IS, TO IDENTIFY AND DISCUSS THE DEFICIE IN THE CODE (OR !F NECESSARY, TO DisrtISS TIE INACCURACY OF EXPERIMENTAL NEASUPEMENTS).
- 7. TO ADDRESS THE OVESTION OF HOW IP1PORTAPIT IS THIS CODE DEFICIFNCY TO OVERALL REstA.TS, I TO PARAMETERS AND ISSUES OF INTEREST,
- 8. TO EXPLAIN WHY TitlS CODE DEFICIENCY MY NOT HAVE AN IMPORTANT EFFECT, OR
- 9. TO DISCUSS WHAT CHANGES SHOULD BE M DE TO CODE MODELS, TO CORRELATIONS, TO NODALIZATIO IN ORDER TO OBTAIN BETTER AGREEE NT SHOULD TK DISCREPANCY, THAT IS, TE CODE DEFICIENC l A SIGNIFICANT IPPACT ON OVERALL RESULTS.
IT IS MMDATORY TO ADDPESS THESE NINE ITEMS IN ORDER TO ASSURE THE TEC THE PROPEP P51YSICS TO S_CALE-UP_ PHENOKNA AND PROCESSES OBSERVED IN S FlR.L-SCALE NUCLEAR POWER PLANT. l l
DISCUSSING AND DEMONSTRATING AGREENNT DURING A L.ERTAIN TIE INTERVAL, BETWEEN EXPER l VALUES OF A S_ INGLE PARANTER (ALBEIT MOST IMPORTANT), THAT IS, OF CLAD TEPPERATURE, AS REPORTS, IS NEITHER SATISFACTORY NOR CONVINCING IF (AS IN TE CASE OF SOE REPORTS) THE O LACK CONSISTENCY AND THE AGREEK NT APPEARS TO BE A CONSEQUENCE OF COMPENSA IT IS NEITilER SATISFACTORY NOR CONVIPCING PECAUSE CODES IIAVE MANY " DIALS" W
/
" TUNING" 0F A CALCULATIJ1 PARAMFTER TO A PARTICillAR SET OF DATA. HOWEVER, THE QUESTION OF A I
_ CODE SCALE-IIP CAPABILITY IS LEFT ITEN AS ONE DOES !X)T 100f HOW INCONSIS l
% C0lTENSATING ERRORS WILL S_ Calf; FROM TEST FACILITY TO RILL-SCALE PLANT.
06/06/86
p DIAGNOSTIC ANALYSIS: ,
FIFLD EDUATIONS .
PURPOSE:
- 2. TO DETERMIE WHETER OR NOT TIF CODE FIRUC111PE ALLOWS IT TO MnDEL 6 tut lRIC/ DESIGN OmRACTER PARTIClLAP NPP.
- 3. TO IDENTIFY PR0ttSSES/ PHEN 0felA LISTED IN RAPK TABLES MllCH MAY BE AFFECTED BY CODE LIMITATIONS, STRtlCTURE OR TUEPICS PROCEDUE
- 1. IDENTIFY GLOBAL PROCESSES /PHENCITNA LISTED IN RAPK TABLES SUCH AS:
PULTIDIENSIONAL FLOWS IN VESSEL l MULTIDIPENSIONAL FLOWS IN SG
- E0RON INJECTION AND SEPARATION DUE TO GRAVilY
- NONCONDENSIBLE GAS EV0Liffl0N, ACCIMLATIONS ETC.
- 2. DETERMlE WHETHER OR NOT FIELD EQUATIONS DESCRIED IN CODE MAMIAL AND USER GUIDE CAN A GLOBAL PR0ttsSES/PHENDENA
- 3. IDENTIFY SCENARIOS IN _PANK TABLES MIIGI ARE AF CIED BY CODE LIMITATIONS
$. DETEW.lE WHETER OR NOT CODF STRUCTURE ALLufS IT TD ITDEL ESIGN OMRACTEPISTICS OF TE NPP w
DIAGNnSTIC ANALYSIS: o CLOSI E E0llATIONS PURPOSE
- 1. TO IDENTIFY IN TE DA DOClfUlT CLOSURE E0llATION WilCH ENABLES TE CODE TO CALCit. ATE A PARTICIUR PROCESS /ROUOON OF INTEREST TO A CfNPOWNT OR TO A SCEPARIO
! 2. TO ASSESS WHETER OR NOT CLOSLE EQUATIONS AS IMPLE19fTED IN T1E COPE, HAVE AN ADE0VATE DATA BASE, ACCURACY AND E ALE-UP CAPABILITY TO BE (GED IN NPP SAFETY STUDIES
- 3. TO DETEINIE WHETHER OR NOT TE SCALE-UP CAPABil.ITY OF CLOSllE E0llATION NEFDS TO E ASSESSFD AGAINST DATA FROM SFPARATE tmLis TEST FACILITIES 11 . TO DETERMIE METER OR NOT, CODE CALCILATIONS PilST E ACCFFIED WITH "CALITION" KCAUSE OF LETTATIONS OF CLOSI E ELATIONS
- 5. TO DETEPMIE METER 09 NOT, SENSITIVITY STIIDIES AND RISK ASSESSIU'T CALCILATION AE _RE0lilRED KCAUSE OF CLOSi1RE FallATiftS EFICIENCIES
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1 CLOSURE'EDUATIONS Af/09/86 M,
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DIAGNOSTIC ANAI.YSIS v I
Cl.0SURE F0VATIONS FIELNEQUATIONS USF:
llSE:
. 0A DOCtMfi
. CODE MANilAl. '
. Usr.R G(IIDF
. LEER GUIDE AFALYSE/ ASSESS:
ANALYSE / ASSESS:
I
- PATA PASE GLOPAL P0DELING CAPABILITIES *
- ACCURACY CODE NlM RICS
- r
- SCALING CAPABILITY CODE STRlETilRE
- APPLICABILITY DETEPMINE:
DEIEININE:
- CAPAPILITIES CAPARILITIES *
- LIMITATI0FS i
LIMITATIONS *
'
- LIMITING DEFICIDEIES LIMITING DEFICIR EIES DEVELOP:
ASSESS EFFECTS RANK TAPLES
" SYFillESIS m
l l
v
- 7. USE PROCESSES /PIB10 PENA RANKINGS LISTED IN TABLE A-3 AND TABLE C-2 TO GEERATE COPPARATIVE PANK TABLE C-4, WHICH COPPAES TE IPPORTANCE OF VARIOUS PROCESS /PilEN0 PENA ELEVANT TO SCENARIO A, TO CODE CAPABILITY TO MODE 1. AND SCALE TI E UP.
TABLE C-4: COPPARATIVE RANKING TABLE FOR SCENARIO A PRDCESSES/ PHEN 0KNA X PROCESSES /PHENOPD!A Y PROCESS / PHEN 0 PENA Z RANK 1 5 4 TABLE A-3 TABLE C-2 3 5 0 CatENTS CONCERNING TABLE C-4 FORAGiVENSCENARIOTHISTABLECANBEUSEDTO:
- 1. EVALUATE TE POTENTIAL CAPABILITY'0F A CODE TO SCALE-UP PROCESSES /PHENOWNA INFORTANT TO A SRCIFIC SCENARIO.
- 2. DETEBMINE HOW ELL MTCHED AE CODE CAPABILITIES (TABLE C-2) TO F0KLING REQUIREENTS (TABLE A-3) FOR TIE SCENARIO.
- 3. EVALUATE IPPACT OF CODE LIMITATIONS AND/0R DIFICIEFCIES.
- 4. ESTABLISH PRIORITIES FOR CODE IPPROVEE NTS.
- 5. ESTABLISH CODE ASSESSENT NEEDS AND PRIORITIES.
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. - _