ML20003D424
| ML20003D424 | |
| Person / Time | |
|---|---|
| Issue date: | 12/04/1980 |
| From: | NRC |
| To: | NRC |
| Shared Package | |
| ML20003D415 | List: |
| References | |
| FOIA-81-16 NUDOCS 8103270103 | |
| Download: ML20003D424 (8) | |
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2 O-PLANNING MEETING ON STATE OF TECHNOLOGY REPORT ON I -
DECEMBER 4, 1980 SUMARY OF KEY POINTS AND ACTIONS Report Scope _
The report will not pre:cribe source tems for the regulatory pro-cess, but it will provide technical bases for source tem judgments 1.
to be made by others later, Key data results will be reported on a current best estimate basis,
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where possible, along with a range of uncertainty.
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The report must cover a range of accidents (including coIe melt)
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not only risk-dominant sequences, to be sure sequences which may 3.
govern ESFs are not overlooked.
Circumstantial evidence, e.g. TMI and other reactor accidents, will 4.
not be included in the report.
3eport Chapters _
Report outline was revised as shown in Enclosure 1.
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1.
It would be more effective to have Chapter 5 on Accident Sequences etc. at the front of the report, hence, it is now Chapter 2, with 2.
title change so as not to preclude (for the reader) the po:si'aility that results from later chapters could change importance of sequence for This chapter will include-a plant diagram (from iodine behavior.
Rogovin report), and the pertinent physical and chemical conditions for each.of the-sequences.
New Chapter 3 should include relevant infomation from the GRASS cod l
3.
development work at ANL and from PBF tests at EGG. BCL will not be also include f.p. themochemistry within the fuel.
l involved in this chapter.
phase chemistry and ORNL will provide the major 4.
Evans at SRL will also be contacted.
aqueous chemistry.
The limitations of TRAP in new Chapter 5 should be ide 5.
the current TRAP version does not include liquid / gas phase iodine of uncertainties.
Denning artition for releases through a pressurizer or quench tank.
p(BCL) has made some estimates of this type in his August 1980 let Gieseke will explore best approach for analysis.
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6.
In Chapter 6 reference aerosol calculations will not include stcam condensation, since NAUA is not yet operational at BCL. Silberberg/
Gieseke, however, will request assistance from Schitarski (KfK) in j
the form of several special NAUA runs or results of completed KAUA cas'es which can be used to infer the effects of a steam environment.
CORRAL will be used for cases involving.' vapor (HAARM/ QUICK do not treat this case).
For Cs1 cases it would be useful to compare CORRAL with HAARM/ QUICK.
The effect of a H, burn in ~ containment on Cs!
thermothemistry should be addressed 10RNL will look into this point).
Sandia will provide core / concrete interaction source terms for BCL.
The ESFs to be considered in Chapter 6 analyses as a basis for Chapter 7 assessment were listed by W. Pasadag, NPR (see revised out-C..: :..:. ~-line).
7.
W. Pasadag will take the lead for writing Chapter 7.
A. Postma will work through NRR based upon results and inputs from BCL and ORNL.
8.
Chapter 8 was elimated by incorporating (a) aerosol effects ex-containment into Chapter 6, and (b) leakage from aux. bldg. into Chapter 7.
Regarding leakage from containment, in Chapter 6 modes of containment failure will be noted but the effect of leak paths on aerosol leakage will not be addressed.
Accident Secuences 1.
An initial set of the following sequences was developed by Cunningham, et al:
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2.
Above sequences will be reviewed by Cunninghma and Pasadag to be l
sure they include all of the challanges to the ESFs. Any changes in sequences will be reported in 2 weeks (12/18), at which time physical and chemical environments for sequences will be provided.
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$ction Item Sumary 1.
Sandia will visit ORNL to discuss and obtain informa Chapter 3 with particular cmphesis on aquems chemistry n for rc Mynatt).
2.
Gieseke will talk with Denning about previous calculati tioning of iodine in pressurizer.
ons on parti-3.
KfX (Schikarski, et al.
results for certain sequ)ences (Silberberg/Gieseke).will be 4.
ORNL will look into thermochemistry of Csl during H
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2 burn (Mynat_t).--
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5.
Sandia will send BCL core / concrete interact
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being incorporated into CRAC (Cunningham/ Blon effects 7
ORNL will try to obtain input from Brooksbank, et al leakageforChapter7(Mynatt).
., on aux-bidg.
8.
SRR will provide up-dated list of accident sequences and corre ing physical and chemical environments by December 18 ond-
,1980(Cunningham).
9.
ORNL and BCL will meet to determine the most effective way to d responsibilities for writing Chapter 6 (Kress/Gieseke).
e 10.
to reach RSR by JanuaryThe first draft chapters are to be compl 19,1981 (all chapter editors / point of me
-contacts).
11.
A special review meeting on draft report will be held in Silver S on January 22,1981 (Silberberg).
r ng 12.
Any extra costs.and effects on on-going work should be identif December 18,1980 (all points-of-contact).
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appa STATF OF TECHNOLOGY REPORT ON RELEASE OF FISSION PRODUCT IODIN OBJECTIVE The objective of this report is to provide the Comission with the best available technical basis for judgments related to the possible exposure of the public to radioactive iodine foller.<ing a serious reactor accident.
Such judgments are needed with respect to features of emergency plans and assessment of current sites, in the Siting rule, in the interim liinimum Engineered Safety Features rule, in Enviornmental Impact Statccents, and in the D2 graded Core Cooling Rule.
The perception of need for this report was precipitated by recent expres-(-
sions of industry concern that the methodology of TID 14844 is very old
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(1962) and does not reflect near-tem experience.
On behalf of potential.
applicants EPRI claims that recent experience, especially at TMI 2 indicates that iodine is a much lower potential hazard than current Guides and Standards indicate.
Past regulatory staff practice has treated severe accidents involving the potential for core damage from three distinctly different aspects:
1.
The release fractions for Part 100 analyses were based on a presumption of substantial core melt to define a single limiting case accident as a basis for a highly stylized ana-lysis on which to make a judgment of site acceptability.
Since Part 100 provided for offsetting unfacorable site characteristics with engineered safeguards, these release assumptions came to be used as the design basis for some, but not all, safety-related systems. As this practice evolved, the assumed iodine releases into the containment atmosphere were recognized as i
being highly conservative but this was felt to compensate for the uncertainty in, and possible nonconservatism of, the release-fractions assumed in for fission products other than noble gases and halogens.
t 2.
Independently cf the foregoing, a design basis was established for control of hydrogen evolved by metal-water reaction based on an assumption of localized overheating of the core, but not melting. This basis was modified (reduced) some years after the issuance of Appendix K to Part 50, but still assumed localized overheating.
3 The increased themal margins provided by Appendix K led to the
' definition of design bases for many systems, particularly for auxiliary systems, which by assuming no core damage dewri played the safety significance of those systems or understated the
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service conditions for which they should be qualified.
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_2 The Comission, in its degraded core cooling cnd related rulemakings, has undertaken to address and rethink in a syste..atic tanner the basic issue -
7 of how the whole range of accidents involving core damage is treated in the regulatory process.
This report is to be a dispassionate reportir.; of facts and available bases for infonned judgment; the judg ents themselves will be made by others.
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STATE OF TECHNOLOGY REPORT ON MASE OF FISSION PRODUCT 103ItE CHAPTER _-
TITLE LEAD ORGANIZAYION SU % RY RSR, NRR Are there clear indications that iodine is ahtays or predominantly i
released in aqueous solution with Cesium as CsI? Are there different release characteristics for different plants or different accident sequences? If so, i: hat cre they?
L' hat actions are indicated with respect to ESF's? That is, is any change indicated to current ESFs so
_ _, they cay function better as intended? If iodine is not likely to be
- --- controlling, what are reasonable candidates for controlling features r==---
1.aking into account effects of aerosol depletion? * ~ -
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1.
Fission Product Fomation BCL Dascribe briefly the fission product fomation in fuel, and the code of release frcra fuel.
Put boiler plate, detailed tables in appendix. Describe biological effectiveness of key fission products.
2.
Accident Sequence Characteristics RES/SRR Develop details of accident sequences that detemine the iodine environment, rank according to likelihood for various plants. I!ay
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require help from SASA. A plant layout diagram such as that used in the Rogovin report will be included as background and for use with sequences. Physical and chemical environments for the sequences will be included.
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3.
Fission Product Release from Fuel ORNL(ANL, EGG)
Describe past, current evidence and modes of analysis for F.P. re-lease from fuel.
Is the release a function of the accident sequence?
E.G., in high pressure sequences with little clad oxidation, cuch eutectic fomation, is release expected to be different from low pressure fifliTre with~cuch" oxidation, bal-looning?-(See NUREG/CR-1715.1_
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Include: (I)releasevs. Temp. Time; themochemical data within the -
fuel and input from ANL and EGG f.p. related work.
4.
Describe basic chemistry of I and Cs1 as in Malinaudas, Campbell talk to staff, treat aqueous chemistry of I ir light of expected ITo the extent that time permits, infomation should be included on re-lease (Chapter 2), transport and distribution (Chapters 4, 6), and EsF loads (Chapter 7) for other significant isotopes (e.g., Cs, Te, Ru, etc.)
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-2 unter conditions in primary, secondary, aux. bldg. systems.
Input on equeous chemistry from ORNL and possible input from contact with Savannah River Lab.
5.
F.P. (I) Transport in Primary System to Containment BCL/Sandia
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Briefly describe TRAP-MELT Code, perfom sensitivity analyses (TRAP) on I vs Cs1 in primary and report results. How sensitive to sequ$nce characteristics (Consider TMLB', S Are there differences between plant types? 2 D, AD, for exa.Tple)?
Most probable physical and chemical fom of I entering containment for sequences (Sandia i
cxpedite tests on Cs! in Air + Steam, Reducing).
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Expected Transport and Leakage Behavior of Iodine -
ORNL/BCL --~ ~
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BCL analyses of aerosol effects in containment for likely sequences (HAMM/ QUICK). Use Sandia results as available to detemine iodine fom tem available for behavior in containment and for leakege via air from containment.
Different w/wo core melt? Detemine I dis-tribution in containment (airborne, settled, slated, deposition in ESF, sumpwater) vs. Time. Are aerosol effects important ex-containment?
Comparisons with CORRAL will be included for cases involving I.
Themochemical behavior of Cs! during H burnwillbeaddresse$.
2 7.
Effect of Accident Loads on ESF's NPR(BCL/0RNL)
ESF's include: containment leakage.. control of aux. bldg. leakage via liquid systems, secondary containment systems, charcoal and HEPA filter systems, containment spray and spray additive systems, and MSIVleakagecontrolsystems(BWRs).
8.
Sunraary of Areas of Major Technical Uncertainty 9.
Conclusions Appendices.
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STATE-OF-TLCHNOLOGY REiuRf ON FISSION PRODUCT IODINE 0
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NRC STAFF AND CONTRACTOR ASSIGNMENTS REPORT CHAPTER CONTRACTOR - CONTRIBUTORS - PHONE NO.
NRC LEAD - PHONE NO.
- l. FISSION PRODUCT BCL R.,
EENNING FTu 976-4864 R. SHERRY (RES) FTS 427-4329 FORMATION
- 2. ACCIDENT SEQUENCE BCL R. DENNING
CHARACTERISTICS M
Ci It M (RES)
- 3. FISSION PRODUCT RELEASE ORNL (A) R. WICHNER/R. LORENZ*FTS
.R.
SHERRY h
FROM FUEL ANL J. REST FTS EGG D. HOBBINS FTS 3
-4E"L (1
R. SALLACH FTS 844-10c SANDIA
>Ts
/FTS ORNL J. T. BELL FTS639-h39 ORNL L. M. TOTH FTS bz4-3U 1
- 5. 1 TRANSPORT IN PRIMARY BCL J. GIESEKE* # FTS 976-4864 R. SHERRY SYSTEM TO CONTAINMENT SANDIA R. ELRICK FTS 840.-7683
- 6. EXPECTED TRANSPORT BCL J. GIESEKE
- FTS 976-4864 S I LBERBERG
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BEHAVIOR BEHAVIOR OF I IN ORNL T. KRESS FTS 624-o558 CONTAINMENT
- 7. EFFECT OF ACCIDENT 'o^DSBCL
ON LOADS ON ESF S ORNL R6 ADAMS FTS b24-7466 R. SHERRY ORNL R.BROOKSBANK FTS 620-6927 CONSULTANT A. POSTMA (509)588-3694 80
SUMMARY
OF MAJOR TECH.-
ALL CHAPTER AUTHORS SILBERBERG/ SHERRY /PASADAG UNCERTAINTIES
- 9. CONCLUSIONS
- LEAD CHAPTER AUTHOR
- SR. TECHNICAL EDITOR (A) ORNL PT-OF-CONTACT F. MYNATT
- CONTRACTOR PT-OF-CONTAC
& NRC TECH. LEAD