ML20028F933
| ML20028F933 | |
| Person / Time | |
|---|---|
| Issue date: | 01/18/1982 |
| From: | Silberberg M NRC |
| To: | |
| Shared Package | |
| ML20027A699 | List: |
| References | |
| FOIA-82-530 NUDOCS 8302070161 | |
| Download: ML20028F933 (3) | |
Text
GG Ifit g e r,iu h. N @
. i l-EAFT - 1/1E/62
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Input Corrents for EDD-11387 (RES-94) on
]k' EPRI letters to FEKA and Chairman Palladino i
A. Letter Culler to Palladino
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General Comments First Paragraph EPRI essentially recommends accelerating all of our source term research.
The pace of this research is controlled by two factors, one, funding and two, orderly development of the experimental technology in areas requiring 1
extension of the state-of-the-art. The ability to accelerate this work is y
controlled in part, and by no means entirely, by the first factor, funding.
A tentative schedule for NRC/RES source term research is attached.
Second Paragraph
' 4 A large segment of the staff and our principle research contractors are' not
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convinced that additional research will undoubtedly show that curre-t cource; terms are conservative by an order.of-magnitude, across the boari '
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accident sequences. What we are'sure of is that the uncertainties associated with predicting source tems are.large (at least on order of J
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magnitude). With our current understanding 'of the complex phenomena
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governing fission product release and transport behavior and accident sequence characteristics.the staff does not recomend the Comission base its planning for those items affected by source term considerations (e.g. einergency planning, siting, etc.) on an anticipated reductions in the accident source terms. The staff does not believe that defensible scientific bases for this decision can be justified at the present time.
In addition, large variations in accident sequence characteristics and plant design make source term generalizai; ions difficult.
(See Chairman Palladino's remarks in an interview in The Energy Daily Tuesday, November 17, 1981 - Attached for background information.)
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Comments on Attachment I Thermal Hydraulic Modeling This work has now started at BCL and is scheduled to be timely for the updated source ters best estimates to be available in early 1983 from the NUREG-0772 follow-on studies at BCL.
4 8302070161 821221 PDR FDIA l
SHOLLY82-530 PDR RL n
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. e Primary Source Characterization EPRI letter essentially lists all of the work currently within this research sub-element as candidates for " acceleration." Our ability to accelerate this work is controlled by any limitations in the orderly development of the-test / experiment / measurements technology and funding. Although the 10 percent cut in FY 1982 for most of the above tasks does impact schedule, progress is in part also controlled by the former reason.
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Water Scrubbing of Fission Products i
RES will be initiating studies shortly at PNL on performance assessment of fission product and aerosol renoval in ESFs. Initially this research program will be developing analytical models for fission product removal in an ice condenser. Following this effort, some experiments may be conducted, j
if necessary.
l Aerosol Transport in Primary Containment System The NRC staff is now participating jointly with EPRI staff (Nuclear Power Division) in the detailed review of the feasibility and technical adequacy, [
of the proposed Marviken program to allow final judgments concerning our direct invo1%enent in the programs. The EPRI and NRC staffs have developed an agreed - upon schedule for the activities necessary to reach:a decision regarding future NRC involvement by June 1982.
j, Corium/ Concrete Reactions u77
'f We agree that core / melt concrete interaction fission product and aerosol release requires additional attention, both experimental and analytical.-
We will be increasing our support for this work. We also expect information on fission product and gerosol release during melt / concrete interactions to be forthcoming in the n-ar future from the SASCHA and large scale BETA
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facility experiments being conducted at KfK in Germany.
Aerosol Transport in Containment n
Prototypic core melt (corium) aerodo/ steam tests are nearly ORNL tests are proceeding at a good pace. UO l tests in steam should compl ete.
l be initiated in mid FY 1982. Additional emphasis on applying the existing codes to analysis of these experiments is needed. We are irt the process of l
issuing an RFP for this effort at the present time.
Containment We agree with EPRI on the timing of the Sandia experiments.
lh (DET - Costello/ Anderson /Arlotto need to address funding, etc.)
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.., Comments on Attachment 3_
Items 1&2 General comments on cover letter apply here.
f Item 3 5
ESF studies being initiated at PNL by RES will provide information for NRR-O reassessment of requirements.
Item 4 NUREG-0771 will be modified and reissued by NRR by June 1982.
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Item 5
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NUREG-0772 follow-on work now in progress. will lead to updated source terms [
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which should be ready for publication in a NUREG by ear 13 1983. This could '
represent the first update to NUREG-0772 by documentation as a supplement.
i Comments on Star'r to Gruffrida ekter_
Paragraph 3_
i Estimate of building failure time (4.5 days) is for a Geman reactor with a Biblis type containment which is stronger (design pressure - 5.7 bar) than i
For even the highest capacity (large dry PWR) U.S. containment design.
example, NUREG-0850 estimates that 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> is the earliest expected failure time for the (large-dry) Indian Point (4.2 bar design pressure) containment h
for accident sequence TMLB.
i The Geman calculations yield quite low releases because of the very late l
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predicted containrent failure times which are not typical of even the strongest U.S. containment designs.
e, Ferhaps we should provide a list of best estimate containment failure l
times for large PWRs ice condenser PRRs, and BWRs for a number of accident sequence for comparison with the German results - also the effects of containment P
l failure time should be shown, perhaps using figure from NUREG-0772 which l
shows aerosol mass density vs. time.)
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