ML20028B491
| ML20028B491 | |
| Person / Time | |
|---|---|
| Issue date: | 10/07/1982 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | Advisory Committee on Reactor Safeguards |
| References | |
| RTR-REGGD-1.145, TASK-OS, TASK-SS-724-4 ACRS-2026, NUDOCS 8212020041 | |
| Download: ML20028B491 (12) | |
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DATE ISSUED: 10/7/82
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N MINUTES OF THE ACRS SUBCOMMITTEE MEETING ON REGULATORY ACTIVITIES SEPTEMBER 8,1982
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WASH'.NGTON, D.C.
INTRODUCTION The ACRS Subcommittee on Regulatory Activities held a meeting on September 8, 1982, at 1717 H Street, N.W., Washington, D.C., to discuss the Proposed Revision 1 to Regulatory Guide 1.145, " Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants".
The entire meeting was open to the public attendance.
Mr. Sam Duraiswamy was the Designated Federal Employee for the meeting. A list of documents submitted to the Subcommittee is included in Attachment A.
ATTENDEES:
ACRS:
C. P. Siess (Subcommittee Chairman), M. Bender, M. W. Carbon, W. Kerr and D. A. Ward Sam Duraiswamy (Designated Federal Employee)
Principal NRC Speakers:
W. Morrison, L. Beratan, R. Kornasiewicz, E. Markee a
and I. Spickler EXECUTIVE SESSION Dr. Siess, the Subcommittee Chairman, convened the meeting at 8:30 a.m.
and indicated that the main purpose of the meeting was to hold discussions with the representatives of the NRC Staff pertinent to the proposed Revision 1 to Regulatory Guide 1.145.
He said that the Subcommittee had received neither written comments nor requests for time to make oral statements from members of the public.
DISCUSSION OF REGULATORY GUIDE 1.145, REVISION 1, " ATMOSPHERIC DISPERSION MODELS FOR P0TENTI AL ACCIDENT CONSEQUENCE ASSESSMENTS AT NUCLEAR POWER PLANTS" z
(TASK NO. EC 724-4) 5 Prior,to holding discussion with the NRC Staff, Dr. Siess provided a preamble indicating that a previous version of Regulatory Guide 1.145, Revision 1, dated
$m September 13, 1977, was reviewed by the Regulatory Activities Subcommittee om gy on November 2,1977; At that meetir.g, the Subcommittee indicated that the NRC 3e$
Staff could issue this Guide for public comment.
Subsequently, this Guide was ESO DESIGNATED ORICIhAL k
Certified By
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t Reg Act Mtg -
9/8/82 reviewed by the then Regulatory Requirements Review Committee (RRRC) on December 20, 1977.
As a result of RRRC comments, several changes were made
.to this Guide.
Since the changes were significant in nature, a revised version of this Guide, dated June 12, 1978, was submitted to the Subcommittee for another review, and it was reviewed by the Subcommitte at the July 5, 1978 meeting. During that meeting, it was brought to the attention of the Subcommittee that there were still some unresolved differing technical issues among the NRC Staff concerning this Guide.
The Subcommittee recommended resolution of these issues piror to progressing further. These issues were subsequently resolved, and another version of this Guide, dated November 13, 1978, reflecting the resolution of the differing technical issues among the Staff, was submitted to the Subcommittee for review, and it was reviewed by the Subcommittee at the December 6,1978 meeting; at that meeting, the Subcommittee indicated that the NRC Staff could issue this Guide for public comment.
Further, it recommended that the NRC Staff provide a presentation to the full Committee to explain the differences between the proposed method in Regulatory Guide 1.145, Revision 1 and the existing practice, and also the technical bases for the proposed method.
Accordingly, the NRC Staff briefed the full Committee on the technical contents of Regulatory Guide 1.145, Revision 1 during the January 4-6, 1982 ACRS meeting. This Guide was issued for public comment in August 1979.
The current version of this Guide, dated August 13, 1982, reflects consideration of public comments received during the public comment period.
Dr. Siess mentioned that previous versions of this Guide were reviewed by the then ACRS meteorological consultants Dr. Gifford and Dr. HacCready, and both of them endorsed the method proposed in Regulatory Guide 1.145, Revision 1 with some comments.
The current version of this Guide was reviewed by Mr.
Hosker, current ACRS consultant, and he endorsed the proposed method in this Guide with some ccmments.
Dr. Siess mentioned also that this Guide has been reviewed and approved by the Committee to Review Generic Requirements (CRGR), and this is the first Regulatory Guide that would be looked at by the ACRS after it had been reviewed and approved by the CRGR.
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w Reg Act Mtg 9/8/82 The NRC Staff indicated that this Guide presents procedures to perform a more realistic and less restrictive estimate of atmospheric dispersion conditions used in 10 CFR Part 100 siting evaluations. The calculational procedures set forth in this Guide represent current practice and have been in use for about five years.
These procedures are also embodied in Section 2.3 of NUREG-0800, " Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants".
Therefore, this Guide merely presents the practice that has already been in use, and the implementation of the provi-sions of this Guide is not expected to result in significant calculational departures or impacts for those applications currently within the licensing review process.
Mr. Kornasiewicz mentioned that this Guide was reviewed by the CRGR on May 20, 1982.
CRGR felt that the proposed calculational procedures provided improved guidance for calculating atmospheric dispersion of radioactivity and potential radiation exposure to the public for the guidelines of 10 CFR Part 100.
However, CRGR recommended that the use of the method included in this Guide remain at the licensee's option for operating reactors. Accord-j inglv, the implementation Section of this Guide had been revised to reflect
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this recommendation.
Dr. Kerr asked whether there is an estimate of the accuracy of the proposed method in Regulatory Guide 1.145, Revision 1, or the old method.
Mr. Kornasiewicz responded that they have heard estimates that the proposed method may be anywhere between a factor of about two to ten more accurate.
He added that they'have been collecting dispersion data for the past five j
years and, after analyzing that data, they may have a better idea about l
the accuracy of the proposed model.
. Indicating that Regulatory Guide 1.145, Revision 1 does not provide adequate information for coastal and desert area sites, Dr. Carbon asked whether the emphasis for calculating the dispersion conditions is balanced between these types of sites and the inland sites. Mr. Kornasiewicz responded that they have only very limited infonnation on dispersion over water.
w Reg Act Mtg 9/8/82 Further, the available infomation is not definitive enough to provide adequate guidance for coastal sites. Additional infomation for calculating the atmospheric transport and diffusion at coastal sites is included in the IAEA Guide on Atmospheric Dispersion in Nuclear Power Plant Siting.
Indicating that some of the commenters feel that the method specified in this Guide is overly conservative, Dr. Carbon asked whether it is true.
Mr. Kornasiewicz responded that the Staff feels that this Guide presents a conservative method, but they do not believe that it is overly conservative.
Dr. Carbon commented that in some of its responses to public comments, the Staff does not seem to respond to the commenter's criticism. He suggested that more explanation pertinent to the commenter's criticism would be appropriate.
Indicating that in its response to some of the public comments the Staff indicates that people who choose to use methods different from those specified in Regulatory Guide 1.145, Revision I should provide adequate justification for use of such methods, Dr. Carbon commented that it is the Staff's responsibility to select and include the best possible method avail-able; if a method better than the one included in this Guide is available, then the Staff should include it in this Guide without requiring that users should justify the use of such a method.
Mr. Kornasiewicz responded that, if the Staff has evidence that some other method is better than the one included in this Guide, they will revise the Guide to include that method.
Dr. Siess commented that the Staff normally tends to take a conservative approach in Pegulatory Guides.. It has always been the Staff's policy that if someone feels that another method is less conservative and better than what it proposed by the Staff, then it is their responsibility to provide justification and basis for acceptability of such a method.
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With reference to a statement in paragraph 2.2.1, which states that
" Alternative methods should also be consistent with these studies, and produce results which provide a monotonic decrease in X/Q with time",
Dr. Kerr commented that he does not believe that X/Q will always decrease i
?.
Reg Act Mtg 9/8/82 with time.
The Staff responded that results of some of the dispersion tests indicate that the average X/Q always decreases with time. The Staff mentioned that it is not the instantaneous X/Q that decreases with time but the average X/Q.
Dr. Siess commented that it is not made clear that the average X/Q is the one that decreases with time, and suggested that it would be helpful if the Staff made this clear. The Staff responded that they would make appropriate changes.
Dr. Siess commented that the outcome of the Severe Accident Rule that is being developed by the NRC might result in some changes to the existing Siting Criteria, and thereby making Regulatory Guide 1.145, Revision 1 and other related Guides obsolete.
The Subcommittee discussed some of the written comments provided by Dr. Moeller and Dr. Hosker (Attachment B, Pages 1-5).
The Subcommittee suggested that the Staff evaluate these comments and incorporate them, as appropriate.
Dr. Siess sought response from the Staff for one of Dr. Hosker's comment which states that the &T or AT/AZ method is not always a good indicator of lateral dispersion and the Staff should reconsider using this procedure in light of the past decade's research and field test results. Mr. Kornasiewicz responded that he discussed this issue with Dr. Hosker and indicated to him that although the &T method is not a good indicator of lateral dispersion under unstable atmospheric conditions, it does provide a good indication of dispersion under i
stable conditions. Further, the Staff has not yet analyzed the results of certain atmospheric dispersion tests that have been conducted, and they believe that, based on the analysis of these tests, they may be able to come up with an indicat;r better than AT or AT/AZ.
After Further discussion, the Subcommittee indicated that it w6uld recommend Regulatory Guide 1.145, Revision 1 to the full Committee during the September 9-11, 1982 ACRS meeting for concurrence in the Regulatory Positions of this Guide.
O Reg Act Mtg 9/8/82 y.
Dr. Siess thanked all participants and adjourned the meeting at 9:25 a.m.
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A transcript of the open portion of the meeting is available in the NRC Public Document Room at 1717 H Street, N.W., Washington, D.C., or can be obtained at cost from Alderson Reporting, 400 Virginia Avenue, S.W.,
Washington, D.C. 202/554-2345.
f.
1 Regulatory Activities Meeting LIST OF DOCUMENTS SUBMITTED TO THE SUBCOMMITTEE 1.
Regulatory Guide 1.145, Revision 1, " Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants",
dated August 13, 1982.
2.
Comments from R. P. Hosker on Regulatory Guide 1.145, Revision 1, dated
-August 30, 1982.
3.
Comments from D. W. Moeller on Regulatory Guide 1.145, Revision 1, dated September 7,1982.
ATTACHMENT A
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27 Wildwood Drive Bedford, MA 01730 September 7, 1982 Mr. Sam Duraiswamy Senior Staff Engineer Advisory Committee or, Reactor Safeguards U. S. Nuclear Regulatory Commission
Dear Sam:
Listed below are my comments on the Proposed Revision 1 of Regulatory Guide 1.145 As you will note, all of them are of an editorial nature.
1.
On page 2, the titles of Regulatory Guides 1.3 and 1.4 are included; on page 3, the title of R. G.
1.23 is not included; on page 3 when R. G.
1.3 and 1.4 are mentioned a second time, their titles are not given; on pages 4 & 5, the title of R. G.
1.23 is not given.
Then on page 9, the title of R. G.
1.111 is not given, but on page 10 it is.
What is the procedure or editorial approach that is being taken?
Whatever it is, it does not appear consis-tent to me.
on page 13, the title of R. G.
1.70 is given.
2.
On page 11 (line 14), reference is made to regulatory position-1.3.2 (which, in reality, is Section 1.3.2 of this same R.
G.).
On page 13 (line 8), reference is made to "Section 2.3.4" of R.G.
1.70.
Was'the latter not a " regulatory position."
Perhaps others are familiar with this editorial procedure but I found it confusing initially.
3.
On page 12 (line 6), reference is made to the " oceans or Great Lakes".
AlthouSh is is minor, I found it interesting editorially that you would be specific about the Great Lakes, but not about the Oceans (Atlantic of Pacific).
What about the Gulf of Mexico?
4.
Page 14 (line 4) -- I think this would read better if it said:"... studies and should produce....."
5.
In the " Regulatory Analysis for R. G.
1.145, Proposed Revision 1," the first page, 2nd paragraph --the word "accommo-date" has a typo; a similar problem exists twice with the word,
" commitment."
Also, in the 3rd paragraph, line 2 -- I would have said: "... staff time could not be allocated for work 6.
Second page of Regulatory Analysis, 1st paragraph -- the words "to the guide" (2nd line), and "of the guide" '1rd line) could be deleted.
In the 2nd paragraph, why are t',e words, "Public Comment" capitalized?
Last line (2nd paragraph) would read better as ".... and which represents In the 3rd paragraph, last line,-it states that "the method described in this guide will be used in evaluating
" "(4) operating reactors."
Yet on page 17, it implies that its application to " operating reactors" is optional.
Back to page 17 of the Guide, why does this say (line 5) " Operating reactors"?
What it actually applies to are " Operating commercial nuclear power plants."
This should be corrected.
$5 b
7 PaEe 3 of " Regulatory Analsysis," (line 5) -- would it not be more accurate to say:
....on the average, to reduce estimates of relative concentration....."?
Same page, 3 lines up from the bottom -- the semicolon should be deleted.
8.
The " Resolution of Public Comments" section contains many errors of English but I assume this will not be published.
-For' example, on the 1st-page, near the bottom for part 2, it states that "The-staff'has considered this comment but have On the second page, item 4, the last sentence: "Others were unable to provide comments."
leaves me' confused.
Other similar problems exist.
I_ hope these comments will be: helpful.
The Revision 1 of the Guide reflects a lot of hard work and is basically a good document.
Sincerely, Dade W. Moeller, ACRS Member
'L.
P.
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U.S. DEPARTMENT OF COfMWERCE I
Metlenel Oceente and Atmospherie Adminletretion i NVI8EWME NT At RE DE A8CH t A804 Af Dar'E 5 post Offire Drawer F.
Oak Ridge Tennessee 37830 August 30, 1982 RT/326 o
Mr. See Duraf svgwy Senior Staff T.ngineer Advisory Cosmalttee on Resetor Safeguards U. S. Nuclear Regulatory commission Washington, DC 20555
Dear Mr. Durainwooy:
The following are my comments, as requested or. August 17,1982, on the proposed Revision 1 to Regulatory Guide 1.145 My coments are mostly editorial in nature, with the exception of (1) and (11), which are techat-tal.
I en pretty wr11 satisfied with the technical accuracy of the proposed Revision, with the possible exception of these two issues.
l (1) p.1.145-4, ifnes 15-16.
The method continues the use of tempera-ture gradient as the mesh stability indicator; Dra. Frank Giffe:d sad paul MecCreedy took issue with this at the November 2,1977 meeting on this revision, and the con-troversy is still continuing. Our probles is that AT (or AT/AZ) is not always a good indicator of lateral dispersion. However, the staff's following sententes alo allow the option of using site-spreific diffusion test results, so 1 as willing to accept the method for Rut I believe the NRC staff should retonsider now.
this prnredure in the 11 Aht nf the past decade's research and field test results.
(2) p.1.145-7, lines 29-30; p.1.145-8, lines 1-4.
The text does not make it clear (although the Appendia does) that the pro-cedure described is to be applied at each distance of interest, and not just at some arbitrary single point.
A sentence clarifying this should be inserted just before the last sent ence of the paragraph.
(3) p.1.145-9, equat ion (5). The subst ript on the wind speed symbol shculd be corrected; compare to line 15 on same page.
I (4) p.1.145-9, line 15. The phrase "h, layer of depth h," should be s
i changed to read "fu:sigation layer of depth h,."
(S) p.1.145-11, line 9.
I object on ar neral principles to describing calculated values of h/Q as "dats points." Cs11 the==
"r.omput ed values" or " computed points" or something similar; " data" always sugsesta something measured, rather than calculated.
.sJan.
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b (6) p.1.165-11, line 9.
Change " free each" to "for each, to inescate that there will be a set of 16 such values.
(7) p.t.145-11, line 17.
Insert " fumigation" bet ween the words "aceter" and "x/Q's."
(8) p.1.145-12, line 5.
"3200 meters" must he a conversion from the Englieb 2 miles, but seems unot cessarily precise.
Why not "3 ka" or "3.5 ks"?
(9) p.1.145.17, line 18.
Delete the consra af ter "X/Q."
(10) p.1.145-12, Ifne 20.
Insert a coimre af ter " values."
(11) p.1.)t5-14, line 26.
Is "4-hour" corrert, rather than "2-bour"?
If so, offer some justification.
(12) p.1.145-15, lines 11-12.
The x/Q value selected is not "the dis-persion condition indicative of the type of release being considered"; ratber It is a gejseguence of that dispr ralen conditf or. Tbts phrase should be re-werded, or even dropped.
(13) p.1.145-16, lines 14-15.
Change "t he appropriate time periods" to " intermediate time periods."
(14) Appendis A.
The Appendig is clearly written and I have no real gustrel with its technical content.
I do take issue with its method of presenting technical results.
I believe the NftC should crecourage sts ataff to r/nlish papers in the reviewed technical literature describing the bases for bounding prosedures such as those des-cribed here.
It is difficult to either endorse or reject an estimation method without seeing a detailed discussion of it s foundat ion.
Remarks on resolution of pu_b1_ic comments.
I have listed these in the order encounte red in the description prepared by the NRC staf f.
I roament 8.1 A request for asethode to deal with wet deposition and compics terrain.
Staff rer:ponse is that these topics g
are beyond the scope of the _0uide.
I as not convinced that this abould be tbc rate; these are both important l
areas that can strongly effect 1/Q retimates. Mowever, they are also topica of current research, and it may not be possible to pay purh in an authoritative way at this time.
I recontsend that the st aff ein toward incor-porating such information an the nest revisico of the Gui dt,.
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Comment 6.3 Aske for basis of setting wind speed during calms
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equal to higher of instriusent starting speeds. As far as I can tell, the staf f did not respond to this query. See also the disc ussion of coreent 5.1, below.
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Ceement 9.7 Requests some justification for using a 4-hour inmi-sation period (rather than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) at coastal reactor sites. The staff has not done this.
I ales raised this point in my comment (11), above; if the Guide is corrett, e reference or justiff ration abould be pro-vided.
Comment 5.1 reints out conflicting definitions of calas in Remula-tory Guides 3.111 and 1.145.
The staff's cesponse is that this apparent conflict is deliberate, and is rooted in the different purposes of the two _0uides.
Ify eyspathy is with the commenter, especially since both definitiers are quite artificial. The staff Phould rethlnk this, and try to Tesolve Lbe Conflict.
It seems needlessly roafusing to change definitions from one document to another.
Cnements 2.1, 4.4, 5.3 These are directed at the method of selecting the bounding esfues of g/Q and the method of time inter-polation.
The stof f really has not answered these guer.tions at all; they have merely responded that there may he other ways to hkin these cats.
I would like to see a more rigorous (cad vigorous) defense of the method recommended.
Cemes nt 3.1 Asks for guidance la determining site boundary distente over large bodies of water. The staff seems to be saying that this is a decision beyond the scope of the C_ui de.
This is probably true, but the staff could be a bit more helpful by suggesting a reference for guidance.
Comment 3.4 Asks that algorithms for the dispersion signes be included an the Guide.
1 agree with the staff that the,s,e are availa5Te elsewhere, but the staff again could be helpful and include a semple reference in the Guida.
Cemeent 6.5 Asks about supporting technical inforastion for the Gu_1.de (s** also my comment 14, above).
1 think this is a 1cgitimate question; NUREC/CR-2269 should be refer-enred in the Guide, either in the Introduction or in the Appendix.
I supe you find the abeve reserks helpful.
If you have any questions, please dor,'t hesitate to call (r78 626-1243).
5 el.
urs.
7 R. P. Mosher, Jr.
I Physical Scientist At swispherit Turbulence and Diffusion Laboratorr RPH:mer
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