ML20148T950
| ML20148T950 | |
| Person / Time | |
|---|---|
| Issue date: | 01/21/1988 |
| From: | NRC |
| To: | |
| References | |
| REF-10CFR9.7, RTR-NUREG-BR-0111, RTR-NUREG-BR-111 NUDOCS 8802030429 | |
| Download: ML20148T950 (115) | |
Text
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O M hAL C UNITED STATES OF AMERICA J NUCLEAR REGULATORY COMMIS510N
Title:
Briefing on Regulation of Transportation o#
Radioisotopes and Results of the Modal Study
1.0 Cation
Washingten . D. C.
[4te: .
Thursday, January 21, 1988 Pages: 1 - 49 Ann Riley & Associates -
Court Reporters 1625 i Street, N.W., Suite 921 Washington, D.C. 20006 (202) 293-3960 ,
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5 6 This is an unofficial transcript of a meeting of the 7 United States Nuclete Regulatory Ccceilssion held on 3 I/2I #88 ..
In the Conen i s s i on 's of f i c e at 1717 H E.treet.
9 'N . tJ . . tJashington. 0.C, The meeting was open to pubIic 10 attendance and observation. This transcript has not been 11 reviewed, corrected *or edited. and it may contain f
Q 10 inaccuracies.
. 13 The transcript is intended solely for general 14 Infcrmationai purposes. As providad by 10 CFR 9.103 It is 15 not part of the formal or informal record of decision of the 16 matters discussed. Expressions of epinion in thl= transcript 17 do not necessarily reflect final determination or bellefs. No 18 pleading or other paper may be filed with the Ccovnission in 19 any proceeding as the result of or addressed to any statenant T. 0 or argument centained herein, except'as the Commission may 21 authorire.
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- i1 UNITED STATES OF AMERICA
( 2 NUCLEAR REGULATORY COMMISSION 3 ***
4 BRIEFING ON REGULATION OF TRANSPORTA??.ON OF 5
RADICISOTOPES AND RESULTS OF THE MOD 4L STUDY 6 ***
- 7 PUBLIC MEETING 8 -
s Nuclear Regulatory Commission 10 Room 1130 11 1717 N Street, Northwest 32 ,
Washington, D.C.
13 14 Thursday, danuary 21, 1988 15 16' The Commission met in open session, pursuant to 17 notice, at 2:17 p.m. , the Honorable MNUC W. ZECH, Chairman of 16 .the Commission, pres'iding.
19 COMMISSIONERS PRESENT!
20 LANDO W. ZECH, Chairman of the Cornission
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21 THOMAS M. ROBERTS, Member of the commission 22 FREDERICK M. BERNTHAL, Member of the Commission '
23 XENNETH CARR, MembJt c' "he Commission 24 XENNETM ROGERS, Marb> '
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, 2 1 STAFF AND PRESENTERS SEATED AT THE COMMISSION TABLE: ,
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4 S. CHILK
, 5 W. PARLER
] 6 V. STELLO 1
! . 7 H. THOMPSON i
j 8 C. MacDONALD '
9 R. BURNETT
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s 3 1, PROCEEDINGS .
2 CFAIRMAN ZECH: Good afternoon, ladies and gentlemen.
3 Today the Commission will be briefed by the office of 4 Nuclear Material Safety and Safeguards and by the Office of 5 Research on the transportation of radioisotopes and the results '
6 of the modal study.
7 The modal study is an evaluation of the safety of 8 certain radioactive material shipments. The Commission 9 requested the staff to undertake this study to confirm its 10 earlier determination that the NRC regulations provide a 11 reasonable degree of safety and that no immediate changes were 12 needed to improve safety.-
13 The staff will also summarize current'and planned 14 activities related to the NRC certification of DOE shipping 15 pack, ages.
16 This is an information briefing this afternoon and no 17 formal Cor. mission vote is expected.
18 Do any of my fellow Commissioners have a'ny opening 19 comments?
20 (No response.)
21 CHAIRMAN ZECH: If not, Mr. Stallo, you may proceed.
22 MR. STELIc e Thank you, Mr. Chairman. I will quickly l 23 introduce the people at the table. On my far left is Bob 24 Burnett. Next to him, Bill Lahs, Hugh Thompson and Chuck 25 MacDonald.
Hugh Thompson will give us a briefing on the .
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. 4 I activitins associated with transportation issues in NHSS and I 2 will quickly give you an overview of the modal study along with 3 Mr. Lahs from Research.
4 The transportation safety record, as you are aware, 5 is excellent. We have not had any real problems. I think we 6 are doing a good job yet it remains an issue of some 7 controversy. I think we will identify recent congressional 8 issues relating to transportation dealing with shipping casks 9 for plutonium via air, which in terns of significance, impacts 10 on the resources, both in dollars and FTE's. It can obviously 11 bo quite significant to our program.
12 Let me then get you started and we will start the 13 briefing and at the appropriate time I will identify the most 14 recent congressional action'and what that could mean to the 15 transportation program.
16 CHAIRMAN 2ECH: All right. Thank you very much. Mr.
17 Thompson, you may proceed.
18 MR. THOMPSON: Thank you.
19 As you know, transportation is one of the functions 20 that we do have. It is an org.anization that is within our 21 safeguards and transportation division. Since some new 22 Commissioners have been added to the Commission since vs 23 briefed the Commission in this area, we thought we would take a 24 few moments to cover some of the background of the interagency 25 responsibilities in this area because it is one in,which the N _ - m h- _
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s 1 we, the Department of Energy and the Department of
- I\ 2 Transportation have some key programs on and a very close interface on'our activities.
3 4 could I have the next slide, please?
4 5 (SLIDE.)
6 MR. THOMPSON: The Department of Transportation has 7 the overall fundamental responsibility for all hazardous 8
material including the radioactive material. They are 9 responsible for the routing activities, the carriers, those lo activities associated with let's say the safety of the drivers, 11 their qualifications, and the qualifications of the carriers 12 for this activity. '
13 Because of our special expertise and that of the 14 Department of Energy, there are certain shipments that have 15 been negotiated through memorandums of understanding for our 16 responsibility and review.
17 The Department of Energy le responsible for the 18 transportation and certification of the radioactive material by 19 their oun activities and their contractors. NRC is responsible 20 for both the transportation of the licensed radioactive 21 natorial of significand quantities, and looking at this, the 22 health and safety aspects. When we look at the Type B 23 packages, we have a health and safety responsibility as well as I 24 sabot 6ge or kind of a physical security responsibility for 25 certain categories, category 1, sptcial nuclear material and.
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- i 4 1 some spent fuels. We do have some. responsibilities.in those
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3 We have health and safety responsibilities and .
4 physical security responsibilities. To understand how that is 5
put into place in today's regulatory framework, the next slide 6 identifies how the packaging is done.
7 (SLIDE.)
8 MR. THOMPSON: There are two types of DOT packaging.
9 one is considered the bulk or strong, tight type packaging, 10 which typically would have contaminated waste, smoke detectors, 11 small medical test kits, small types of things which have a 12 rather minimal health hasard and should be able to withstand 13 most normal transient types of incidents but would not be 14 expected to survive any major accident conditions.
15 If you look at the way the regulatory framework is 16 established, the DOT transportation limits, the amount of 17 radioactive material that would be in a package to such'a small is amount, the public health would be protected even if that 19 material were released. NRC in our certification program 20 provides its high integrity containers so there is no release 21 from the packages and use that approach to protect the public
. 22 health and safety.
23 There is a Type A package which is frequently 24 considered a little stronger from the DOT aspects, low level
( 25 resins, clean-up from the reactor waste and it would not again a
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1 present a serious hasard if the~ material leaked, but it does l 2 have a bit more capability than just the other strong bulk, 3 tight one, and then aga'in the Type B package that we have.
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4 In our regulatory framework, the Type B package would 5 he for spent fuel, high level waste, irradiated reactor 5 components and some highly radioactive radiological devices.
i 7 In these cases, you could have a rather serious health hasard ;
5 3 8 if the contents of the material were spilled or leaked or had a !
l 9 criticality accident as part of the fuel shipment aspects. l 10 In making our judgments in order to establish our t j
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I 11 criteria, they are kind of hypothetical accident conditions.
12
{ There are things like a 30 foot drop test, certain fire tests, I
13 a puncture test.
i These are what we call performance standards, l 14 that we evaluate or actually test the packages to make our I -
- I 15 judgments that the material, the quality control of these 16
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packages are sufficient to adequately protect the public health l I
d l 17 and safety. )
is
\ (s LIDE. )
19 MR. THOMPSON:
The next slide identifies what we say I 20 is our memorandum of understanding, primarily with the
- 21 Department of Transportation, which sets out the 22 responsibilities not only for the licensing review but also j 23 I
what type of energency response capabilities we have initially j 24 and for follow-up activities. *
(, 25 DOT does serve as the national competent auth9rity
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1 for transportation of. radioactive material. ,They do develop 2 the standards and requirements for the Type A and low specific 3 activity packages that we just talked about.
4 NRC has the responsibility for the Type B and the 5
fissile material packaging and the lead role in investigating 6 accidents where damages occur on NRC approved packages. It is
. 7 the review and evaluation of the packages that we have the 8 responsibility for.
9 Again, our memorandun of understanding calls for 10 exchange of information and inspection and enforcement programs 11 in the various areas of jurisdiction.
12 Likewiss, we have a memorandum of understanding with 13 the Department of Energy.
14 (SLIDE.)
15 MR. THOMPSON: The next slide shows that primarily 16 for'the activities on the Nuclear Waste Policy Act, back in 17 November of 1983, we established the framework where we in fact 18 put into place our consultation arrangements for discussions 19 with the Department of Energl and basically they indicated 20 theit' intent to have NRC certify the DOE shipping casks for the 21 spent fuel associated with the Nuclear Waste Policy Acc.
22 Subsequently, as you probably know, Congress has 23 enacted a requirement that in fact they are required, not just 24 by the memorandum of understanding, but the law does now
( 2a require that.
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We establish periodic meetings to exchange (I 2 information on technical issues, policy type assumptions and we 3 meet'about twice a year. I think the last meeting we had was 4 in September where we just basically went over the status of 5 their program, discussed various technical issues concerning 6 the licensing of their casks. They have not got any casks'in 7 for us to actually review. We have had some preliminary 8 meetings with DOE on those activities.
9 With respect to one of the key issues that we face in 10 the transportation activity is the increasing desire by the 11 Department of Energy to have NRC certify DOE casks. I think 12 when we prepared these initial briefing slides, late last year, 13 we had a proposal down to the commission on ways to address
. 14 some of the impacts this program might have on our own .
15 programs.
16 NRC certification is not required for DOE with the 17 exception of the Nuclear Waste Policy Act casks. There has 18 been a significant increase from the Department of Energy in 19 applications for the timeframe, fiscal year 1988 to 1992.
20 These include the Naval reactors program, West Valley high 21 level spent fuel casks, the Nuclear Waste Policy'Act, and 22 recently the WIPP transportation casks for transuranics.
23 As you know, we maintain a fairly limited amount of 24 resources in this area to review our actual applications. We 25 have about 85 or so applications,a year that we must review.
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1 Again, we really had no formal procedures between NRC and DOE l 2 for package review except for the Nuclear Waste Policy Act.
3 :'
(SLIDE.)
4 j MR. THOMPSON: The next slide provides a projection 5 of what this impact he potentially on our review activities. (
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' I 6 We normally have somewhere around 8 to 10 FTE's available to do
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7 these types of reviews. The peak workload for this coming year 8
was such that we felt and we recommended to the Commission that .
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l it take some actions to assist in reducing and streamlining the 10 process of our review of DOE applications, and the Com:nission i
11 has sent a letter to Secretary Herrington. We are still l 12 waiting for their response.
13 There is one activity that is identified on this l l 14 chart which is the plutonium air r.hipment casks. This l 15 !
particular estimate of resources in TY89 was put in there prior l 16
- f to the recent action by Congress to have a much more stringent '
17 evaluation of that particular type cask than we currently have. :
18 j
The resources associated with that review right now, this is 19 l more of a consultation type review at,tivity, based on our l * {
! 20 1 current review' standards, and it would take significantly 21 i
higher resources if we had to respond, assuming there is a j 22 foreign country that wishes us to respond to the new i
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i 23 requirements.
I j 24 COMMISSIONER BERNTHAL: Let's see, the original 25
] rather extraordinary language that has been proposed with .
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l I respect to 'those plutonium shipments was modified in the end '
(4 2 cons'iderably, so where are we now?
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Mk. THOMPSON: , I guess the language is still fairly i 4 stringent. '
5 MR. stELiot I was wondering it genatal counsel was i i
6 familiar with it. I 7 .
MR. PARLER: General counsel heard about the issue ,
a you are talking about yesterday and he has somebody that is !
9 going to provida him with research and an interpretation of the !
10 Murkowski amendment as it was recently enacted by congress. As l 11 I understand it, there are two schools of thought. l Under the 12 Murkowski amendment, the criteria are essentially the same as i 13 I the Scheuer amendment which the Congress adopted either in 1975 !
14 l or 1976, but with the aircraft test added to that, or whether I 18 the criteria in the Murkowski amendment are substantially f
16 beyond, more severe than in the Scheuer amendment. You have 17 that problem to deal with as well as the aircraft test. !
la !
I as told the Murkowski amendment in its legislative 19 history is fairly clear. What I as trying to find out is i 20 t fairly claar in which one, the first one, which is pretty much !
21 l the same as the scheuer amendment plus the aircraft test, where 22 the criteria have been substantially increased. ,
23 From what I have heard, these criteria are presumably <
24 thought to have been substantially increased. I au looking at 25 that. ,
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. 12 1 COMMISSIONER BERNTHAL Yes. Certainly not to the I 2 extent as the original Murkowski propos51, which would have 3 required half velocity crash tests. .
4 MR. STELLO There are two criteria as well as the 5 two issues related to aircraft, one dropping and the other 6 crashing aircraft.
7 COMMISSIONER BERNTRAL: The actual tests that would 8 have been required were extraordinary. Those were dropped.
3 They were changed in the final version.
10 MR. THOMPSON: They were slightly changed but they 11 still had a significant requirement along the lines of full
! 12 scale air crash tests, if we were not able to certify or have 13 an independent body certify that the test conditions that we 14 established wer's equivalent to a worst case scenario.
I think 15 that is what the general counsel is looking at.
f 16 MR. STELLot There is also another issue, that unless 17 clause does not apply to the case of dropping it from an ~
18 aircraft, for example, or may apply.
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19 j MR. PARLER We will get you an ansvar fairly 20 quickly, i
21 MR. THOMPSON: It is important that we do have a' good 22 reading on this. Based on my discussions with Harold Denton 23 and others, there is still one country that is very interested 24 I, in continuing to pursue this activity, so it is somathing we 25 need to review and respond to fairly promptly. Since it is-a d
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13 1 requirement that the country support financially those
(\ 2 activities, we will need to assure that we have a program in 3 place and that they know how we are going to carry this out.
4 Otherwise, it will divert significant funds from review 5 activities. '
i 6
- (SLIDE.)
- 7 MR. THOMPSON
- This slide will essentially identify
- 8' the steps the commission has taken to assist us in evaluating
, 9 the additional resources that we need. We have requested that 10 DOE certify the packages prior to submittal and to prioritize l j 11 their package review needs. There are a number of packages :
4 j 12 that have been in here some years. We typically in the past f l 13 have been able to almost always meet DOE's requested date for I
i 14 their Naval reactor packages. '
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15 As you know, we intend to still work on their l
16 packages until DOE decides a different priority will be in 17 place.
I don't have right now a projected date to get a ,
response.
4 18 We do 'have a system in place, pending a response by 19 DOE on this activity. ,
20 COMMISSIONER BERNTRAL Do we have the authority to f i
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i "require" DOE to certify those packages or is this a request?
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MR. THOMPSON: This in essence is really a request. {i 23 What DOE has the authority to do is to certify their own i
24 packages and once they are certified, they would be use'ful with l
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j i s_, 25 the exception of the Nuclear Waste Policy Act shipping I
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14 1 packages.
2 COMMISSIONER BERNTHAL: We can't meet that mandatory 3 directive?
4 MR. STELLO: General counsel may know.
5 MR. PARLER' The .rcas that we can direct DOE to come 6
to us either to be licensed or to be certified are those areas
. 7 that Mr. Thompson has already alluded to, that is the Nuclear 8 Waste Policy Act as amended recently and that are covered in a
)
- 9 particular section of the Energy Reorganization Act of 1974.
10 There is nothing in the Energy Reorganization Act of 1974 as 11 amended that I recall that would require DOE to come to us to 12 get casks certified. -
13 Therefore, other than the Nuclear Waste Policy Act,
, 14 the thing is entirely voluntary on DOE's part. I would assume, 15 but I do not know, that there would be substantial motivations i 16 on' their part to come to this agency to get their casks
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17 approved, for fairly obvious reasons.
18 MR. THOMPSON 0bviously, there may be some exceptions 19 to the thing if there is a particular need and one or two l 20 casks, for them to certify the casks first and we would be 21 !
prepared to accept their judgments and their recommendations as l 22 to which to put the priority on. It may be the WIPP casks
! 23 sight receive priority or the Naval reactor casks, whichever
! 24 one it would be. Until otherwise, we are putting our emphasis 25 on the Naval reactor casks consistent with our past. practice
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. 1 and the resources we have available.
- i 2 COMMISSIONER CARRt Let me make sure I understand f 3 this. You said there were 857 '
4 MR. THOMPSON: Typically we will receive a total of 5 applications for amendments or new cask reviews at about 45 6 reviews a year.
7 COMMISSIONER CARRt Different casks?
8 MR. THOMPSON: Different casks, different designs, I
9 same designs but maybe a different loading factor.
10 MR. BURNETTt Internal modifications to an existing 11 cask.
t 12 MR. THOMPSON: I guess there is something like 225
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13 l approved NRC certified casks for various shipments, spent fuels '
, 14 --
15 !
COMMISSIOMER CARRt I assume those approvals are !
16 generic in that if they meet that cask and that kind of l 1
17 loading, they can keep doing it without coming bach. !
18 '
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MR. THOMPSON: That's correct. !
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COMMISSIONER CARRt It is an one time shot. l l
, 20 MR. THOMPSON: There is a five year renewal, each '
21 five years they would come back for renewal of 1! hat 22 application.
23 COMMISSIONER BERNTMAL: Let's see, what about f:he 24 response to the Commission's request that DOE certify their 25 designs and,give us priorities?. Have they thus far responded
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16 1 and indicated what they are. going to do?'
(\ 2 MR. THOMPSON: No, sir.
.)
As I mentioned earlier, a second part of our 4
responsibility deals with the physical protection requirements 5 that we have on nur shipasnts.
6 (SLIDE.)
7 MR. THOMPSON: The next slide identifies ia summary a
that the two main areas requiring physical protection is the 9
first category, Category I, and the spent fuel requirements.
10 There are small differences with respect to the armed escorts, 11 where the spent fuel does not automatically have armed escorts 12 all the time. You would only have armed escorts in urban 13 areas. The spent fuel does not necessarily have a specialized 14 carge vehicle and we do have unarmed escorts for the spent fuel 15 in non-urban areas, 16 The two key areas that we have looked at from a 17 sabotage or a physical material accountability control are the 18 spent fuels and Category I materials. Tha Commission has 19 proposed a rule at o.Te time to relax some of the requirements 20 on spent fuels based or, an evaluation of the significance of a 21 sabotage of a spent fuel chipment. We will be evaluating that 22 in the years to come, as to whether or not that is an 23 appropriate reduction in our physical protection capability of 24 that material.
(,, 25 (SLIDE.) ,
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17 1 MR. TMoMPsoN: The next slide identifies what we *
( 2 think is a key area with respect to the emergency response role 3 of the NRC and essentially we really have a coordination role 4
or a communication role as the primary function, in assuring l l
5 the state agencier. th Departhent of Energy and other affected 4 agencies informed of the accident. We provide specific l 7 information on NRC certified packages and we offer other i a
technical advice as requested on protection of the public 9 health and safety issues. We would only assume radiological 10 L control at an incident scene until state or local authorities j 11 arrive.
12 We have never had that occur. I wouldn't anticipate 13 we would ever be the first on the scene for any particular l
14 reason, but that is the responsibil.ities that we have.
15 We experience each year a number of events that come i
16 into our incident response center, 25 to 30 type transportation f 17 accidents a year! Of the 25 events in 1985, four involved some !
l la material release. In fact, NRC Region IV responded to one l 1
19 which was a yellow cake collision with a train in North Dakota, 1 l
20 which received a good bit of NRC oversight and attention at 21 that particular time' in 1985. In 1986, we really did not have 22 to respond to any events that involved some material release.
23 1 CONNISSIONER CARRt When you say information on the j 24 NRC certified packages, that is packaging? We don't look at {
j
-v 25 each package before they ship it, do we, as long as,they are -
18 i
1 meeting our requirements?
2 MR. 'fHOMPSON: That's correct. It relates to the 3 specifics of the design, the characteristics of the package, l
- I 4 shielding characteristics, what ma'cerial night be shipped in 5 it.
6 COMMISSIONER CARRt The inpression I got reading this 7 van each package that is shipped, we have to okay it before it
- 8 goes. That's not correct.
9 4
MR. THOMPSON: That is not the case. In fact, much of 10 the inspection of the transportation activities is done by the 11 states. They may occasionally spot check a transportation 12 shipment through a state, part,1cularly on spent fuel.
, Some 13 t states make an effort to inspect the package shipment at the
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border and inspect it carefully and may escort it through the 15 state or the local transportation areas, which depends on the ;
16 i
sensitivity to the area as to what the local authorities do.
17 CHAIRMAN ZECH:
l I know we don't have many of these '
1 1
, 18 incidents. My experience would lead me to believe that the NRC 19 has responded rather promptly. i I would hope that this is the 20 case and we vould continue to give priority to anything like i 21 this that happens. We should have an NRC responsible person on i
22 the scene just as soon as va can. I hopa that is what we do.
23 It looks like that is what we have done. I hope ve vill 1
1 24 continue to do that.
25 MR. THOMPSON: Most of these are fairly small type
t . .
19 !
1 incide,nts. I believe there was one recently in Richland, 2 Washington, where there was a truck overturned with some 3 contaminated soil. We evaluate whether or not NRC's presence ,
4 would be of assistance to either the state or local, we will !
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5 consult with them, and if there is any need or request for our 6 assistance, we respond promptly. ;
7 CMAIRMAN 2ECH: If there is any doubt at all, if 8 there is any question about it, we should go, whether we are 9 asked or not. I would like to make sure that happens. The !
10 regions can do it and we should back them up if they need help j 11 from Headquarters. (
12 MR. STELLO: As the slide also indicates, I guess {
13 there was at least one occasion when we were the first at the j 14 scene. When we are -- '
15 i CMAIRMAN ZECH: We tako charge until properly 16 relieved.
I 17 \
MR. STELLO: That's right, until relieved by the !
la state or local authorities. ,
19 COMMISSIONER BERNTRALt At any given time on the 20 average, how many shipments of spent fuel are in transport in
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21 this country? I 22 MR. MacDONALD: Approximately 100 per year, 100 23 shipmento per year.
24 COMMISSIONER BERNTMALt Every third day on'the ;
25 average. Are you saying shipments per year? I am saying on ,
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i i cny given day, hov.many shipments are in transport?
I '\ 2 MR. BURNETT We are running about 100 to 200 3 shipments a year.
i 4 COMMISSIONER BERHTMAL How many days on average does 5 each shipment take?
l 6 MR. BURNETTt on an average, some of them are short 7 like one day, some are two or three. ,
8 1
COMMISSICHER BERNTMAL: It sounds like that on the 9 average, at least every day there is a movement.
l l 10 Mk. BURNETTI There is about 52 shipments coming in 11 from abroad, coming into portsmouth,. Virginia. Most of those 12 shipmento go from that shipping dock into the Savannah River, 13 which is less than a d y away. That might give you some 14 indication. There are some others, j '
l l
15 COMMISSIONER BERNTMAL l I get the picture. l
- 16 KR. THOMPSON
- But the number of shipments obviously
! 17 as we move to the high level vaste repository are going to be .
18 significantly different and certainly to the extent that we l
19 have evaluated the en'rironmental aspects associated with those, 20 va vill probably re-vanit that in part of cur update of our l 21 environmental assessment activities that we are planning to do 22 in any event.
23 MR. BURNETTI The average days in transport is going 24 to change because you will have a single repository and you can 25 see the impact.
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, 1 COMMIssICHER BERNTRAL: We are really beginning to !
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2 develop a pretty good statistical base for expressing the k
j 3 safety of these casks, I would assume.
4 4 4 MR. THOMPSON: Bill may address some of the
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I 5 statistical bases. I think we didn't use our nuclear I i
6 transportation shipments, to develop the accident rates because !
i 7 it was few compared to what I would say the gasoline tankers i 4 are. When you are really looking for significant statistical l t
9 numbers, those numbers way outweigh ours. It is an important 10 area because very careful records are kept, the accidents are f 11 evaluated.
12 !
One of the' key issues that we keep facing, both in ;
13 congress and with our own individual reviews is the adequacy of f 14 our regulations. f The history, the accidents, have always [
15 proven that the program that we have established has reached !
i 16 the highest degres of performance in protecting public health i 17 and safety.
18 As you may know, in 1977, we evaluated through an f 19 environmental impact statement, the adequacy of our regulations 1 i
20 :
to consider whether we needed to make any significant changes l 21 to increase those. It was based on the inform'ation that had l 22 !
been developed, public comments were received on it and the j 23 safety record we had achieved to date.
24 The commission concluded that the present regulation's
(,, 25 provided a reasonable degree of safety and no immediate changes -
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- t 4m ,.4 dum ewman. 4 4 +* ~ '
. 22 .
I were needed to improve safety. Again, this was reaffirmed O 2 recently by the office of Technology Assesement, when they l t
3 concluded that the regulations provided a high level of public (
4 protecticn for spent fuel shipments, in fact, probably the l
5 highest level of any of the activities, hasardous material 6 transported, and this was given that we implemented the quality {
7 assurance programs that were utilised and relied upon by the 8 industry in developing and designing and building these casks.
9 In addition to those two studies, we have conducted I i
10 some full scale studies, full scale testing. I guess there is 11 a photo that many of you have probably'seen. There is always 12 the train and the caek muoting shortly at the intersection. .
t 13 Despite that aspect, and you may want to put that particular 14 slide up, we felt it.va's important to do a modal study which [
15 looked at more than just the one point.
16 (SLIDE.) 1
\
17 >
MR. THOMPSONh All these casks performed sufficiently {
la to adequately protect the material involved. The modal study 19 gave a much broader review and a risk assessment review of the !
c 20 activities associated rather than just the one frame that you 21 can see there, one dimensional hit, although it is a fairly 22 dramatic one, it didn't really satisfy everybody's concerns 23 with respect to the transportation cask issues.
(
24 l Bill. you might want to talk a bit about what we were I 25 able to do in the modal study to further evaluate the adequacy ,
r i
1 l
. \
23 1 of our r'egulations. i 1
1
(% 2 MR. LAHS: You heard Hugh generally describe the a
I 1
3 approach to our transportation safet$y regulations. He has !
1 4 alluded to the radioactive material package performance 1
5 requirements, including thoce directed at assuring that the j 6 proper protection is being provided in the event that one of 7 our packages becomes involved in a severe transportation (
4 4 accident. i i
1 9 He just got done mentioning the 1977 environmental
)
i 10 impact statement which provided a risk perspective en all l
11 l
radioactive material shipments in the United states including i 12 spent fuel.
- J '
) 13 I mention these items because they are really the 14 starting point or reference point for the modal study 3
15 discussion.
j 16 i
The principal use of the modal study is it was taken l 17 i
together wich things like the full scale test that you just saw I 18 i<
which I think provides information from which people can make a 19 better judgment on the adequacy of our transportation l 20 v regulations and also I believe upon which past Commission 21 conclusions with regard to the adequacy of those regulations 22 can be made.
23 As mentioned, the modal study focuseu specifically on 24 regulation adequacy with regard to spent fuel shipments, which t, 25 could become involved in severe transportation accidents. -
t
4
, 24 l
1 Jr.et a brief background, when the Commission made its- [
! 2 decisio:. back in 1981 on the adequacy of the regulations, I h 3 think they recognized that for spent fuel and certain other i i
j 4 shipments, that the nature and the quantity of the materials !
5 shipped dictated some need for some continuing action. They 6 essentially told us to address two issues, which are shown on
~
7 !
this first viewgraph.
l {
? 4 !
(SLIDE.)
I 9 MR. LAHSt People always ask, what is the i 10 relationship between our existing performance standards, that !
i
' l 11 is things like the 30 foot drep and the unyielding service, the 2
, 12 fire test,.the puncture test.and the related acceptance a>
13 criteria, and the environments that we can really see in real [
14 world accide't n situations, f
15 secondly, they asked, could we characterize what the !
i '
16 potential radiological hazards might be if a spent fuel 1
t 17 shipment became involved in what most people would consider a !
is severe transportation accident.
t
] 19 l
(SLIDE.J 1 20 MR. LAHS To respond to this directive, we decidad i
1 21 that a study could be undertaken to evaluate the level'of i l
l t
i 22 safety provided by spent fuel casks designed to our existing {
- 23 regulations, wj.th the assumptions shown on the slide.
l (
! 24 The general approach would be to try to evaluate the i j y 25 performance of those casks against severe accidents which have t
i
. [
t 4 l l
) -
(
i
' ~
1 .
25 i 1 historically occurred involving non-nuclear' shipments using
, f 2 road / rail transportation.
3 over the course of this study which lasted -- it l 4 started in 1981, there were essentially three difforent ;
l 5 contractors involved, the latest of which was the Lawrence (
6 Livermore National 14boratory and it is their contractor report j l 7 which is most frequently referred to by the modal study.
'8 In doing the study, Livermore really had to give f 9 :
consideration -- had to address two main considerations. First !
10 of all, since we have a performance standard approach to our f
i 11 rogulations, if you think of what do we have out there, we have j
. 12 casks of different designs. They all meet our regulations but t l
t 13 you could have casks that ship BWR, PWR, assemblies, shielding I 14 material can be different, closure designs can be different.
15 I
Anyofthosecaskscanbetheonethatsomed$y,somewhere l
14 i along the line could become involved in a severe transportation
{
17 accident. That accident could,also involve a wide variety of la forces, both mechanical and thermal.
19 (SLIDE.)
l 20 MR. ZAHS : The first step in the study essentially l i
21 involved determining the magnitude and likelihood of the forces 22 which we really could see in real world accident situations, 23 focusing especially on those which had the possibility of 24 compromising cask safety functions. That means containment 25 integrity, shielding, criticality control. This information W --a A__.._,a - . . - - e us > . a %% . u, - - ? -
14 !
I was derived from a review of the histori, cal record of all road' (
2 and rail accidents and was supplemented by route and other 3 informational type surveys.
4 What resulted from this was a distribution of i 5
accident scenarios which tradictad % e occurrence rate of cask 6 interactions with a variety of targets. As this viewgraph !
l 7 shows, one of the main classes we divided things up into are f a
what we call parts that were' soft relative to the cask, things l 9 like people, you drive in your automobile, trucks, buses.
10 There are classes of targets which can be hard, things like [
11 bridge columns, hard surfaces either adjacent to the roadway or :
l 12 maybe below bridges where a shipment could go through a bridge !
13 railing and fall to the surface below. !
14 There were other parameters which were obviously ,
15 important to characterine the magnitude of the forces which i l
16 could be involved, both of a mechanical and thermal nature, and 17 there are a lot of them addressed in the study itself. Several -
18 are illustrated in the brochure which you have a copy of.
19 l
The major ones as you might expect are things like 20 velocity, impact angles, what is the object surface and whether 21 there is a fire involved.
l l 22 (SLIDE.}
23 MR. IAMS: The crucial step in the whole study was 1
24 the next one. Remember that the level of' safety is really l t
25 provided in the cask designs themselves. The crucial step in e
t *
- h a p y t- e c E_ _M,%,C N ~ N W h e** W w - Ft--&~"~T'W' " ' ' " - - " - ' ' '
-*--e-~ N'- ='"'
'. i, .. .
27
. l 1 the study' was to try to come up with a design definition of a
( )' 2 cask or c2sks which could act as a surregate to the level of 3 safety that is being provided in the. regulations.
\
4 Basically what was done is we defined a 5 representative road and rail cask which had features common to 6 the casks that are out there, but which had capabilities 7
deliberately selected to only just meet the existing regulatory 8 requirements.
9 Once that was done, the remaining steps really became 10 more mechanical and that was essentially to evaluate the.
11 representative casks against the accident environments which 12 had already been defined.
13 We used computer codes to essentially evaluate the 14 degree of damage that these casks could sustain, both of a ,
15 mechanical and thermal nature, and then )ooking at that damage, 16 made a canservative assessment on what the radiological hazard 17 was that could result, what that hazard could be and what the 18 magnitude would be. '
19 The hazards were essentially of two types.
20
. (SLIDE.) -
21 MR. LAMS:
This is the first one. 'That involves the 22 possibility obviously of a material release. For that to .
23 happen, you have to have an accident severe enough not cnly to 24 rupture the cladding of the individual fuel routes within the
( ,. 25 assemblies to allow the mate. rial to escape to,the inside of the -
..,.Q...-=7 - ' -
~ '
j -
28 1 cask but you also have to have an accident severe enough to
() 2 somehow cause a violation in the cask integrity.
3 The slide here really shows the possibility where you A
might have seal damage and release through a failed seal.
5 (SLTDE.)
6 MR. LAHSt This viewgraph shows the other type of 7 hazard which could result and that is shield degradation. In O
8 our representative casks, we chose lead as the shield material 9
and the' illustration shows an example of where if you had a 10 head on impact of one of these casks, you might get lead slump, 11 lead could actually move forward causing a void in the shield 12 and an increased radiation level external to the cask, even 13 though the event might not lead to any material release from 14 the cask. -
15 In the final steps of the evaluation, the package 16 response and accident force likely analyses were combined.
17 Estimates were made that given that an accident occurred, what 13 would be the damage sustained by the representative casks.
19 That damage was placed into various categories as shown in the 20 next viewg~raph. ,
21 (8LIDE.)
22 MR. LAHS: This slide is really a damage magnitude 23 diagram, where if you are working from the bottom left to the 24 upper right, you are seeing increasing levels of damage. As
(' _, 25 you go up, you ar,e seeing increasing levels of mechanical 4 4
I S
, e m_ A da . . _ zGr - M**A -" # * * # * *"# '"" ' ^ - ^ ^ ^ ^ ^
~
i T I . .
29 l i 1 damage, which'in the study wac characterized by a measure .of
() 2
'the maximum strain achieved in the containment shell of the 3 cask. 'As you go out the abscissa what you are seeing is 4
thermal damage which is being characterized by a measurement of 5 the maximum temperaterc ct the ecnter line of the shield. ,
6 Through this process of taking these representative 7
casks and subjecting them repeatedly to the loading conditions 8 which we established for the real accident forces, for each 9 individual case, we were able to generate the information 10 necessary we felt to characterize a relationship between our 11 regulat' ions and some baseline level of safety that is being 12 provided.
- 13 At this point, I am going to discuss some of the 14 results of the study.
15 (SLIDE.)
16 MR. LAHS: The study provides three perspectives on 17 the safety tha't is being provided by our existing regulations.
18 First, the study results are as to cask accident likelihoods, 19 in terns which compare the potential radiological hazard to .
l 20 values which currently exist as acceptance criteria in our 21 existing regulations in Part 71. Secondly, we have a 22 perspective which is a risk calculation, which is similar to 23 what was done in the 1977 environmental impact statement. That 24 was done for all materials but spent fuels was singled out.
k_j 25 1 Here we are just focusing on ris,k from spent fuel accidents. -
I
. l l
6
_,.-%-- -__.m m_ _ -
__ ___,_ A__, .ym.,_.,,, .-. _ _ . _ __ :
t ,. .
- 30 i
1 Finally, to give people some feeling for how casks
() 2
~
could respond to say a serious accident, a ve'y r severs 3 accident, what we did is try to evaluate how our representative 4 cask would respond if it had been involved in several severe !
5 accidents that are actually on the historical record. t 6 (SLIDE.] ,
7 MR. LAHS: Here the results indicated that if our s 8 representative cask over a period of time was involved in 1,000 9 accidents, the time estimate would be something like 50 to 100 '
10 years, depending on shipment mileage, and of those 1,000 )
11 accidents, 994 would result in forces being applied to the cask 12 which would be probably less than the forces' that are being 13 applied by our hypothetical accident conditions. Therefore, we 14 wouldn't espect any radiological hazard to be created. .
15 COMMISSIONER BERNTMAL: 950, not 994.
16 MR. LAHS: I am going to the bottom. 994 is correct.
17 994, we would expect no radiological hazard but even in the 18 remote event that something did happen, we think the hazard 19 would still be far below the hazard that is applied by our 20 acceptance criteria.
21 The 994 is made up of two components. Firdt, there 22 is 950 of those 1,000 events roughly that would involve cask 23 interactions with soft targets, and therefore it is those 24 targets that would be taking most of the damage.
(_, 25 If you talk about the other targets, harder classes .
. =
9
-w ._..x m m_ _ , - . _ . _ _ m em - _ _ _ _ _ _ _
l-
. 31 1 of targets which could be'hard, even in that class, there are
() 2 44 events which essentially would cause damage which would 3 3 probably lead to no radiological hazard. Why?
4 For example, you might hit a bridge column, maybe the 5 velocity is less than 30 milec an hour, or maybe you hit a 6 column at 70 miles an hour but it is only a glancing blow, or 7 even with hard classes of targets like bridge columns, there L L
- a are certain sizes of columns which are soft relative to these 9 canks. The column is going to fail before the cask will.
10 Even though there might be a fire, which could be hot 11 enough and long enough, you always have the question, iJ the [
12 cask really involved in that fire.
That is how we get the 994. -
13 How about the remaining six? !
14 '
(SLIDE.) -
15 MR. LAHS: The study showed that of the six remaining 16 accidento, four fell in the second box on the left side, which !
17 is an area where we are predicting minor cask damage. What l i
.18 does "minor" mean? !
If you look at the structural response, we .
19 are talking about maximum strains between .2 and 2 percent, not 20 a lot of damage. i I
21 The hazard that could be created by such an event f i
22 might be seals, the seals could fail so you could get maybe i
\
23 some release of radioactive gases and some volatiles. '
Again, (
24 when we evaluated the situation, the radiological ' hazard that
(, 25 is created 1s still far below the values that are, stated as our l
. l l
l l
1 '
~
! . 1
. 32 .
I 1 acceptance criteria. - i h 2 Only when we get to the next box up, when we think 3 about the possibilities of major damage and it really only 4 applies to accidents where we are talking about the much larger i 5 strains, 10 percent and abova .ptnin sccidents, could we 6 predict radiological hazards which could equal or might exceed 7 by factors of four or so the values that are currently in our ,
8 acceptance criteria.
9 In the outer range, the striped area, you are talking 10 about extremely rare events. You are almost guessing. To give 11 you a feeling for what that means,. we estimated that maybe 1 in 12 100,000 accidents would fall into that striped area. To give 13 you a feeling in terms of time, that would be like an event 14 roughly every 500 years.
15 Because of that open area, we tried to provide a 16 second perspective shown on the naxt viewgraph.
17 (SLIDE.) .
18 MR. LAHSt We subjected our representative cask 19 design to a selected number of real world severe accidents. I 20 am not going through all the accidents. The point of this 21 slide is that when we did that, we found out that 3 of the 4 1 l
22 led to predictions that the damage would fall in that lower 23 left box.
The Caldecott Tunnel fire was kind of a borderline 24 case. Only in one event, and that was the Livingston train 25 yard fire accident in Louisiana in 1982, could,ve come up with -
4 Q------ P owee- m, y 3 --. wow .. ,--me e m _ p , p m y,m w ,, ,, _
t . .
33 1 predictions where we could say, there could have been major
(\ 2 damage to'the cask. That particular accident involved a derailment of a number of vinyl chloride and petroleum tank 4
3 4 cars. The fire lasted for several days or a couple of 5 explosions. We essentially put our representative cask in that '
6 accident environment and we came up with predictions that if 7 cask had been at the right place, we could have gotten 8 temperatures ranging from 600 to 720 degrees.
9 Finally, the last perspective --
10 COMMISSIONER BERNTHAL: What exactly is the physical 11 damage that occurs in that box?
i 12 MR. LAHS: In that box, for our representative cask, i 13 remember our cask had a lead shield, and you are obviously 14 talking about lead melting, so you could either partially lose 15 the shield, the shield could melt, when it contracts, voids I 16 could be created, you could have an increased direct radiation 17 hazard and because of the fire you could have seal failure.
18 \
You could have actual radioactive material
- releases out through 19 the seals.
10
, COMMISSIONER BERNTHAL: There are no dangers from the 21 lead molting of structural damage to the internals that you 22 could begin to compromise --
23 MR. LAHS: The expansion or something like that?
24 COMMISSIONER BERNTRAL: 'Such that you could get
(,j 25 criticality or anything like that. -
a !
I h i__ . . . . .-. =-
34 1 MR. LAHS: No. When we looked at' criticality, it is
(~%
2 mentioned briefly in the brochure, but the safety that is being 3 provided against criticality accidents is such that the 4 estimates that we were making on criticality events were 5 numbers that are just not believed, 10 to the minus and I can't 6 remember the number offhand, but it was like 10 to the minus 13 7 or 14, it is hard to honestly believe that such an event is 8 critical.
9 COMMISSIONER BERNTHAL: Seal failures would occur 10 from over pressure if they occur?
11 MR. LAHS: From either mechanical damage or some of 12 these seals could degrade as the temperatures get higher than 13 say 550, depending on the type of seal you are talking about.
14 MR. THOMPSDN Even in these cases, the radiation 15 dose levels are not so significant, they are like four times 16 the regulatory limit, that is like four rems per hour for a 17 shielding loss and it is a little more complicated with the 18 more aerosol release but it is still, making a lot of 19 assumptions, like less than 25 rem dose to somebody who would 20 be like 100 feet away w,ho might be in the cloud. That is a 21 nigh dose level but it is not like you are going to have a 22 lethal dose.
23 MR. LAHS: That is a fair characterization.
24 Obviously as you are getting up, as you go to the upper levels,
( ,. 25 the uncertaintie,s, what if, and it is diffi, cult. ,
- -~ -
. . :,. . .. . - - , . - ..s--
35 l
1 COMMISSIONER BERNTHAL: In aged fuel like this, hged
( 2 spent fuel, what is the principal remaining volatile. component?
3 obviously if the iodine we tend to worry about is all gone, 4 r,any of the noble gases I guess are'all gone.
5 MR. LAHS! Casius, .hich is also --
6 COMMISSIONER BERNTRAL It is not really a volatile.
7 MR. LAHS It can be. Krypton is around as a gas, i
8 (SLIDE.)
i 9 MR. LAHS: The last chart is the third perspective 10 which is a risk perspective, a study similar to what was done 11 in the 1977 environmental impact statement. .
Again, just 12
. focusin'g yoor attention on th's bottom line, the 1977 study 13 estimated that if you looked at accident risk associated with 14 spent fuel transportation, they.came up with a number of .0004 '
15 of latent cancer fatalities per year.
16 We think the study that Livermore did is a little 17 more precise, a little more accurate. Our re-evaluation led to 18 1
a figure that was about one-third of that value.
19 !
All of what I talked about today is Available in a 20 published report, NUREG/CR-4829. It was peer reviewed by the 21 Denver Research' Institute. I honestly believe that taken 22 !
together with other things, that the study does provide some ;
23 new insights for people to make judgments on their own on the 24 adequacy of the regulations. The brochure you have was 25 s
produced with the expectation that the study's ,results could be -
s.
_ % maw -- s s v :u- . x7 -< a nm - - - - - - - - , -- - --.-. - - - -. _ _
36 l 1 more accessible and comprehensible, not only outside the agency {
(%
i 2
but within the agency.
3 MR. THOMPSON: We congratulate Bill.' I know it is a 4 popular document. I think we have provided thousands of these 5 documents primarily to the state liaison officers for their use 6 in advising the Governors, and to state legis3stors. I think 7 Bill has made presentations to the state legislators. It is a 8
well received report and one that I have found to be very 9 useful in trying to communicate to the public in what the risk 10 with respect to transportation of spent fuel is today. It is a f 11 very, very volatile issue, particularly in the states that are 12 trying to look for reasons to be opposed to anything dealing i 13 with the spent fuel high level waste repository.
14 There are still some issues that we have before us . i 15 that we are looking at this year in coordination with Research, 16 such as the nodular cast iron material, which is a non-17 specification material that is subject to more b'rittle fracture i 18 concerns. We use and have licensed some of these casks for 19 independent spent fuel storage applications but not in l 20 transportation because of the brittleness.
21 other countries have licensed these caskc'and there 22 has been some attempt at one time to involve NRC in agreeing to 23 the approval of that type of cask design. We had a research 24 project look at this activity and.we concluded that some 25
_, additional information may be necessary, certainly we have 4
-___ x r ,r- *m-~. m; g ,,_e -
.___, y_ _
- 37 1 serious doubts right now' based on the in' formation that we have,'
2 that it is useful to try to use nodular cast ir as part of 3 the material. I think Research will be providing us with 4 information shortly on what our expectations would be, whether 5 it is worth pursuing.
6 I don't believe we have a license application before 7
us and it is probably not useful to spend a lot of NRC money in l 8 this activity at this time.
9 COMMISSIONER BERNTHAL: Is that the German design?
10 !
MR. THOMPSON: Primarily the German design. ]
11 i COMMISSIONER BERNTHAL: The concerns are both about ;
12 mechanical integrity under stress and response t'o high 13 temperatures? What is the principal concern?
14 MR. THOMPSON: Certainly brittle fracture.
15 MR. MacDONALD: Not so much the temperature as the 16 fracture and toughness of the material. As Bill went through l 17 the modal study, using some. strains of 10 percent or so. and 18 higher than that for the materials that are currently used in 19 spent fuel casks, the nodular cast iron casks would not have 1 20 that type of ductility, you may not be able to develop the full 21 strength of that material before you would have a failure. The 22 concern would be of having a cask breaking open. We believe 23 this should be looked into before proceeding in that area.
24 There are concerns about the material,'
v 25 reproduceability of the material and the material being a non-
%i ..
4 L,. - % w.M- V my =m - -
s.
38 1 specification,.not having a specifica, tion for that material.
pi q 2 The code such as the ASME code would not accept that material 3 for nuclear application. There are a lot of questions that 4
would remain before we would see moving into an area of using a 5 material which certainly en -appscrunee would be an inferior 6 material.
l l
7 COMMISSIONER BERNTRAL: On what basis has Germany )
8 approved it? Do they have less stringent standards than we are i
9 applying?
10 MR. MacDONALD: I reclly do not know. l 11 t MR. THOMPSON: The next two issues primarily relate {
12 l to using the current type of material we have and either going 13 with a different design, which is the rectangular design, and I l 14 think most of the casks you have seen are basically circular j 15 and the question is you may get a greater capacity in a cask 16
- resulting in fewer shipments, but you again have a more 17 difficult time being able to demonstrate it meets our .
18 structural requirements in Part 71.
19 Likewise, the credit for fuel burn up. We talked 20 earlier about criticality issues and our ability to really 21 understand what our safety margin is from a criticality aspect. 1 22 In transportation, we do not have and do not give credit right 23 now for fuel burn up. That is one of the issues we will l
24 continue to look at. People feel they can get increased
(_, 25 storage capability in the existing cask it we.will give them ~
M ,,.w"" #
a
i 39
. 1 credit for that. -
(~%' 2 q There are questions on accountability, recordkeeping, 3
measurements, different criticality in the rod, if you knew you 4 had a general burn up, being able to know what it is in the 5 various physical locations within the rod itself, spent fuel 6 rod itself. Those are some of the issues that are important.
7 Finally, the issue of the plutonium in the air 1 8 transport. I think that is the one we talked about earlier. j i
9 It is one which could take a significant amount of agency ,
10 l resources to do. Certainly depending on what the general l 11 counsel comes up with on what the requirements really are, it 12 could require us'to develop new criteria and then conduct 13 various testing associated with those new criteria.
14 COMMISSIONER BERNTHAL: What is'the credit for fuel 15 burn up? I understand in principle. Can you give me a 20 word 16 or less summary?
17 MR. THOMPSON: I will let Chuck MacDonald give you a I
18 20 word or less. '
i
! 19 MR. MacDONALD: Our hope is to increase the fuel load 20 capacity in the cask, by increasing the capacity, you reduce l l
21 the number of shipments that you would have to make. !
j 22 MR. THOMPSON:
. I think it is a criticality issue.
23 The question is how much of the fuel, if you hac fresh fuel in 24 there, you have certain poison type barriers as part of the k_, 25 basket structure that you, place the spent f.uel in and ship it' L
iL ,, . . _ . - . ..
l .
40 1 in, such that if you put that in even a pool of water, just for
( 2 loading and unloading, that you won't have a criticality .
3 accident. That is it has to be flooded. The time that you 4 really flood the transportation cask, unless you have an 5 accident, it is ree.11y leading and unloading.
6 MR. MacDONALD: As far as the function that the fuel 7 basket would perform. It would hold the fuel assemblies, there !
8 would be a neutron absorber as part of that fuel basket and i 9 there would be some spacing in there for moderation of the i 10 neutrons so they could be absorbed, and if you can do away with i l
11 the neutron absorbers, do away with some of the spacing --
12 COMMISSIONER BERNTHAL: For high burn up f'uel?
13 MR. THOMPSON: That's correct.
14 MR. MacDdNALD: For higher burn up as the reactivity 15 would decrease. It certainly is not an issue that as fuel 16 comes out of the reactor, that it does have less reactivity.
17 COMMISSIONER BERNTHAL: I guess I am surprised it i
18 makes such a' difference going from regular burn up to what we 19 call high burn up. Maybe it does.
20 MR. THOMPSON: No, we don't give credit for any burn 21 up. l 22 MR. STELLO: We assume it is fresh.
23 COMMISSIONER BERNTRAL: You assume all fuel is 24 fresh.
(_, 25 MR. STELLO: Highest reactivity.you can get in a fuel
} s .
~
41 1 is assumed. Then you have to add' absorbers, poison, to. *
( 2 accommodate the --
3 COMMISSIONER BERNTHAL$ The question before you is 4 whether to offer a credit for the burn up.
5 MR. STELLot You give them a credit if you can get 6 more fuel back in and take out some of the poison.
7 COMMISSIONER BERNTHAL: That is extraordinarily l
8 conservative.
9 COMMISSIONER CARR You want to make sure they don't 10 unload a recently' loaded fuel. ;
11 MR. THOMPSON: The question is how you would go about j 12 having assurances. There is no clear measure that you can make 13 that says this is 10 percent burn up or 1,000 megawatt day burn 14 up. .
15 MR. STELLO: Your accounting and recordkeeping system 16 if you do this is going to be very, very significant.
17 MR. THOMPSON: Perhaps we could back off some, but if 18 you back off some, is it worth it to go through the whole 19 process.
- 20 MR. STELLot We don't know but that's the end of our 21 briefing. -
I 22 (Laughter.) l l
23 COMMISSIONER BERNTMAL: You didn't know that, did l
24 you? I 25 MR. THOMPSON: No, I didn't. Again, just to re- -
.m L
42 i 1 emphasize it, transportationisprobabihtheareainwhichthe
( 2 public comes in closest contact with it and it is one where 3 almost every state has an area of interest.and one that I think 4 will be before the Commission for some time. We wanted you to 5 be aware of the things that we were working on and to let you 6 know that we think this is a program which has achieved a very 7 high level of safety and assurance of adequate protection of 8 public health and safety.
9 CHAIRMAN ZECH: Thank you very much.
4 Any questions 10 from my fellow Commissioners? Commissioner Roberts?
11 COMMISSIONER ROBERTSt No.
12 "
CHAIRMAN ZECHt, Commissioner Bernthal?
13 COMMISSIONER BERNTHAL: I don't really have many 14 questions, I guess. I also want to compliment Bill, the author ;
15 of this study, on the work he has done, in two respects. One, t
16 although I wouldn't attempt to analyze the technical details of 17 the product here, you presented it in a way that I think is 18 very good. ;
It is a very good educational document, to say the 4
19 least.
.i 20 I also like the fact that the name of the author is 21 on the document. That is something that we have t'alked about 22 very often in connection with research work that comes out of j 23 this agency. That is not just because I especially want to 1
24 contribute to his publication list, which is fine. It cuts
[ ,
25 both ways. That means he is accepting responsibility for this l
II a
. 43 1 product and it is not under the sometimes gray imprimatur or '
( 2 the U.S. Nuclear Regulatory Commission only. !
3 I would encourage that sort of thing. Let's get the 4 authorc' names on it and let them stand by their work.
5 The one other trer I t.'euld mention is there must have 6 been a good deal of rather detailed technical work that is 7 behind this somewhat more popularized version here. Have you i 8 published that work and do you intend to? .
9 MR. LAHSt That is the NUREG document.
10 COMMISSIONER BERNTHALt It is only published as a i
11 NUREG. Are you going to put it in a journal? Are there
. 12 appropriate portions for a journal? l 13 MR. LAHSt The people at Livermore have published 14 some papers on the study. In general, the results of this 15 study have been published.
16 COMMISSIONER BERNTHAL: Again, I would encourage you 17 to the extent, both for your own professional good and to 18 maintain th'a principle here, that those parts that are 19 publishable, you be encouraged to put them in a standard line 20 journal.
21 MR. STELLO: We will go back and make sure there 22 !
isn't any further work that we can publish. I 23 COMMISSIONER BERNTMAL: Again, I compliment you on a 24 nice job. *
/
(_,, 25 MR. LAHSt To be fair, a lot of Hugh's people worked 4 4 4
S m .
- s Mdar ++WM w --- - m m esa -.m .. m se '
w-
- 1
- e
- I
,. . 44 1 very hard and you have'a great graph,ics department, too. 1
, 2 COMMISSIONER BERNTHAL: We ought to be doing more of i
3 that sort of thing for public education as well as for other 4 reasons. It is a great contribution to helping the public to 5
focus on where the real risks are in this business and also are I ;
6 comparing the risks in this business to many other risks that 7 we live with on a daily basis.
l J l j 8 That is really'all I have to say. It was a good l 9 briefing. Thank you.
j j 10 CHAIRMAN ZECH: Commissioner Carr? '
11 COMMISSIONER CARR No questions.
12 CHAIRMAN ZECH-: Commissioner Rogers?
j 13 COMMISSIONER ROGERS: Just one question. What is tho'
[ 14 material of the outer shell? .
15 MR. LAHS: Stainless steel. I 16 COMMISSIONER ROGERS: I just want to reinforce what i
. 17 Commissioner Bernthal just said. I think this publication is .
18 a very attractive. I think it is a good thing to represent the I 19 commission by and I would like to compliment you on a fine job.
20 MR. LAHS: Thank you.
21 CHAIRMAN ZECH: As we all know, a number of states, 22 as you mentioned earlier, have been very interested in 23 transportation matters on a continuing basis for nuclear 24 materials that will be going through their states.
b 25 Are we working close enough with th,e Department of e
0
- 4 0
-- -- =w CU m,&gm 4 ^ _ % m- ,-1 - -- -
45
. 1 Transportation, de we need to develop any new guidance or (h 2 policies as far as transportation is concerned?
3 MR. STELLO: We have very good relations with them 4 and work very closely. We have made changes over the years.
5 Quite frankly, if some of the legislation that is at issue 6 prevails, it will drive the Department of Transportation and us 7 to do considerable work. The bill provides for specific 8 regulations to be developed jointly.
9 CHAIRMAN ZECH: We do have a continuing relationship.
10 MR. THOMPSON: Our relationship has been good. I 11 think we have no communication problems that I am aware of. It 12 is important th'at we do this, we maintain that type of 13 communication.
14 CRAIRMAN ZECH: We haven't had many serious problems 15 occur in these packages. Every so often, we have a problem.
16 We have had a few. Is there any additional things you are 17 aware of that we should be doing on packaging of radioactive la wastes? Do you think the casks and our' responsibilities are 19 adequately taking care of the radioactive waste 20 responsibilities that we have or are there other things we 21 should be doing? '
22 MR. THOMPSON: We are very comfortable with the level 23 of protection of the public that we have with our current cask
~
24 designs. The area that is being pushed by the industry to a
(_j 25 certain respect is,getting credit for fuel burn up. They would 9
e e
46 1 like to anybe reduce.some of.that margin. We obviously are
( ~s being very careful and thorough in our review before we elect q 2 3
to reduce any of this margin that we have to reach the level of 4
protection we have today, just to make sure that we don't back 5 away from it.
6 There are also questions concerning the need for 7 continued guards for the spent fuel. That is the other area 8
where there is some pressure by DOE and the industry, that we 9
should not continue that level of protection for that material.
10 As long as we feel it is appropriate to do that, we will 11 continue to do it, to keep that level of protection.
12 It gets into emergency response. If there is one 13 area that a question keeps coming up, it is the adequacy of the 14 local people who are trained or would be first on the scene of 15 an accident with a radiological consequence. If a spent fuel 16 shipment was involved in a transportation accident, what is the 17 appropriate local response.
18 We believe and I think DOE in the recent law will 19 find a need to have an increased level of training at state and 20 local' emergency resp.onse organizations. I think our role has 21 been to focus just on the adequacy of the cask design in those 22 areas. I am comfortable with ours. There will still continus 23 to be an issue with the state and locals on that.
24 .
COMMISSIONER CARRt Do we have a feedback and lessons
(_, 25 learned from,the accidents we have had? , .
6 g S L_ .
. ~.
47 1 '
MR. MacDONALD: Our accident' experience as fab as s .
l 2 Type B packages are concerned has been there has been no i t
3 release tron thpce packages. That involves some 50 accidents j 4 for a 15 year period or so. Spent fuel' casks have'been '
i .
I 4
5 involved in accidents but tbsy ;arfurm au designed. !
6 The smaller packages that are not designed to retain ,
7 their contents in an accident, they do release the contents in t 8 accidents. Mowever, the contents are limited so that it is not I
9 a significant health and safety hazard.
\ 10 The system does seem to be working.
11 COMMISSIONER CARR: I would hope we do review them i
? 12 for lessons learned, if th' era are any.
13 I
MR. STELLO: I think the answer is yes but the 14 lessons learned are more as to how to respond to the accidents.
4 15 The typical accident you have is --
16 COMMISSIONER CARR All I am saying is look at them 17 and make sure there is not something we can learn.
I 18 MR. STELLO: From the point of view of how to deal i
i 19 with them; yes.
- 4 i 20 CHAIRMAN ZECH:
j Wasn't there a recent incident l 21 involving radioactive waste from TMI II material?
I 22 MR. THOMPSON:
I remsuber one where there was a train 23 collision. I want to say in St. Louis.
4 24 CHAIRMAN ZECH: A rerouting problem.
v 25 MR. BURNETT It was up in Minnesota and it -
l i
j .
1
m ___--.__.______m___
'i . , <
- i 48 i
- . N
- 1 accidentally got put on an off track, niisrouting and it was 1
~ !
); 2 picked up later.
. t j
1 3 MR. THOMP5ON: I believe a train hit. '. !
4 l
- CHAIRMAN ZECH
- What is the most significant accident j f
j 5 to one of our casks that we have had? l 1
j 6 I MR. BURNETT Chuck, how about the one a few years i i
l 7 ago out west where the cask was actually thrown off the truck?
t 8
, MR. MacDONALD: Yes. That would probably be the one f I
I 9 outside Oak Ridge, Tennessee, which contained an overfuel cask.
t
- 10 i The truck took some evasive action to avoid a collision. The s 1
11 package went into the side of the ditch. The driver was a i 12 fatality. The cask separated from the vehicle and slid some
- 1 -
13 200 feet and came to rest.
l I
The people out of Oak Ridge i 1
14 Nation 41 Laboratory responded to the scene and recovered the 15 package, took it into the National Laboratory.
, It was 16 !
l inspected and it was only superficial damage to that package. '
17 CHAIRMAN ZECH: No radiclogical release?
18 MR. MacDONALD: No releases. We have had cases where
{
'. 19 there are heavy concentrated loads, where problems with the 1 20 trailers may crack and have weld failures. In this case, the j 21 cask essentially carries the trailer. The safet9 is not really 22 dependent upon that trailer and you see the industry coming j 23 back to redesign the trailers in that type of equipment.
4 24 CHAIRMAN ZECH: Let me thank you very much for a very 25 interesting and valuable presentation. I agree with the '
i
' 1 l l l .
l o l
1 .
t ..
49 1
, recognition that has been given to you, Bill, for your ,
2 contribution to our agency and to our country.
3 The modal study represents a significant body of work 4
and I think the findings represent certainly mone confirmation 5
that our regulations do prc'.ide a reasonable level of safety in 6 the transportation of radioactive material. I think the study 7 was very useful in that regard.
8 It is important that we continue our close .
9 association with the states and with the public regarding 10 transportation of radioactiva material. I do believe we should 11 continue a close relationship with the Department of 12 Transportation and the Department of Energy also, especially 13 with regard to our safety responsibilities.
14 This is a matter that we don't discuss at this table 15 very often. It is very important. I think all the 16 Commissioners agree with me that certainly we all feel a very 17 keen responsibility in th.is area of nuclear materials as well 18 as the reactor programs.
19 I think the briefing today was very useful, very 20 helpful ard very professional. Thank you very much.
We stand 21 adjourned.
22 (Whereupon, at 3:30 p.m., the meeting was adjourned.)
23 24
- C 25
. . . _ _ % %. -*,- - se w _ - - - - - -
'-' -~
! , o b
l 1 .
- l "s
2 REPORTER'S CERTIFICATE '
j 3 l 4
This is to certify that the attached events of a
- 5 meeting of the U.S. Nuclear ReguJatory Commission entitled -[
t l 6 l
l 7 TITL2 OF MEETING: Briefing on Regulation of Transportation of Radioisotopes and Results of the Modal Study (
8 j i
PLACE OF MIETING: Washington, D.C. I
' (
9 DATE OF MEETING: inursday, January 21, 1988
(
4 10 r e
1 11 i
were held as herein appears, and that this is the original !
l 12
}
transcript thereof for.the file of the Commission taken !
! 13 r
{~ stenographically by me, thereafter reduced to typewriting by i
l j 14 t se or under the direction of the court reporting compa,ny, and 15 that the transcript is a true and accurate record of the 16 foregoing events. i l
11
/I
- a L-is
- r---- ---- t ,
1, 19 Suzinne{Ioung*L------ Y gp -- - i i
! 20 ,
i ! j 21 . l l ! j 22 Ann Riley & Associates, Ltd.
' I i i 23 1
24 i
.j
- I h___,-,---- ,_----~c----~~
-l--~-----~------ - - - - ~ ~ ' -
c-
- ~
1 i TRANSPORTATION OF RADIOACTIVE M ATERI ALS . 9 e 9 a
-- - - __- _ _ m____ _ _ , _ _ _
s i' P
~
i . REGULATORY RESPONSIBILITIES . i h 1 I i AGENCY SCOPC r l j . I DOT . TRANSPORTATION OF ALL HAZARDOUS MATERIAL INCLUCINO , i l RADIOACTIVE MATERIAL. RESPONSIBLE FOR ROUTING OF i SHIPMENTS. . DOE TRANSPORTATION OF RADIOACTIVE MATERIAL BY DOE * ' i . i AND ITS CONTRACTORS. f . 1- 8 NRC TRANSPORTATION. OF LICENSED RADIOACTIVE MATERIAL. RESPONSIBLE FOR ROUTING SAFEGUARDS FOR LICENSED M ATERI AL.
/
- . a PACKAGING CONSIDERATIONS I PACKAGE SAMPLE CONSEQUENCE OF DESIGN TYPE CONTENTS PACKAGE FAILURE CRITERIA .
AGENCY . BULK OR URANIUM ORE AND MUST WITHSTAND l STRONG, CONCENTRATE. PLASTIC MIN 0 MAL COND6TBOMS INCIDENT TIGHT AND PAPER WASTES FROM HEALTH HAZARD TO TRANSPORT f I CONTAM0NATED AREAS. . 1
? DOT eMOeCE DETECTORS. 49 CFR PART 173 i
j MED4 CAL TEST MITS . i < MEDICAL ESOTOPES. DCES NOT PRESENT MUST WITHSTAND TYPE A Low LEVEL RESIN A SERIOUS HEALTH NORMAL COND8TSONS p 8
---- CLEAN-UP WASTES HAZARD OF CONTENTS OF TRAQsPORT i DOT rRou REACTORS RELEASED 49 CFR PART 173 s
3 } SPENT FUEL. HIGH SEF490US HEALTH HAZARD MUST WITHSTAND TYPE B LEVEL WASTE, 8RRAD8ATED BF. CONTENTS RELEASED. NORMAL TRANSPORT
---- REACTOR COMPONETS. SH8ELDING IS LOST, OR ANO SEVERE ACCIDENT ,
NRC RADoooRAPHeC oev Ce3 CRmCAUTY CONTROLS FA8L CONDITIONS 10 CFR PART 71 ) ) t 1 . 2
o_ -
- . o .
p l 1 DOT /NRC MEMORANDUM OF UNDERSTANDING
?
i JULY 2 1979 1 0 NRC l DOT . d
- SERVES AS NATIONAL COMPETENT
- DEVELOPS STANDARDS / APPROVES
) 5
~
AUTHon0TY FOR TRANSPORTATsON TYPE B AND FISSILE MATERIAL 1 4 OF MAD 00 ACTIVE MATER $AL PACKAGES 1 2
- DEVELOPS STANDARDS / REQUIREMENTS
- LEAD ROLE IN INVESTIGATING
$ FOR TYPE A AND LSA PACKAGES ACCIDENTS WHERE DAMAGE, OCCURS TO NRC APPROVED PACKAGES 1 . l { i d-DOT AND NRC
- SMFORMATION EXCHANGE. CONSULTATION AND ASSSSTANCE
! . WITNON AREAS OF SPECIAL COMPETENCE - I
- INSPECT 90N AND ENFORCEMENT PROGRAMS WITNIN l SNDIVSD*JAL AREAS OF JURBSDICTION f
1 i .
M
, NRC/ DOE PROCEDURAL AGREEMENT FOR NUCLEAR WASTE POLICY ACT SHIPMENTS NOVEMBER 3, 1983 .
~
.) i 1 ESTABLISHES WORKirlG RELATIONSHIP FOR TRANSPORTATION ACTIVITIES UNDER THE NUCLEAR WASTE POLICY ACT s
- EXPRESSES DOE'S INTENT TO USE NRC CERTIFIED PACKAGES ,
H ll PROVIDES FOR PRE-LICENSING CONSULTATION ON PACKAGE DESIGN, DEVELOPMENT, AND TESTING . J. F l ESTABLISHES PERIODIC MEETINGS TO EXCHANGE INFORMATION ON TECHNICAL ISSUES AND POLICY ASSUMPTIONS
~
NRC OF DOE CERTIFICATION PACKAGES NRC CERTIFICATE NOT REQUIRED FOR MOST DOE ^ SHIPMENTS, DOE HAS OWN CERTIFICATION PROGRAM k
- j ., RECENT LEGISLATION REQUIRES USE OF NRC CERTIFIED l PACKAGES FOR NWPA SHIPMENTS .
i
- SIGNIFICANT INCREASE IN DOE APPLfCATIONS IN FY 88 - FY 92 (NAVAL REACTORS, j WEST VALLEY, NWPA AND WIPP) .
LIMITED RESOURCES TO REVIEW INCREASED
. DOE CASELOAD -
- NO FORMAL PROCEDURE EXISTS BETWEEN DOE .
A N i.) NRC FOR PACKAGE REVIEW (EXCEPT FOR NWPA)
' - - - -- - - - -- - - -^
PROJECTED TR AN S PO RTATI O N CASEWORK
}
} LEGEN D
.,e__ I COMMERCIAL NAVAL REACTORS
[I DEFENSE PROGRAMS 12 2- b WEST VALLEY m Pu AIR
- $ NWPA s~- . NWPA PRE-APPUCATION .
! mani M TECHNICAL ISSUES AVAILABi_E RESOURCES 4-- . 4mm
~~ - -
O .- . . - - . 1987 1988 1989 1990 1991 1992 FISCAL YEAR 6
] r-
~
o ?, - I l MEASURES TO MANAGE EXPECTED I - SHORTFALL IN NRC RESOURCES .
- REQUIRE DOE TO CERTIFY PACKAGES PRIOP, TO SUBMITTAL.
- SHOULD RESULT IN MORE COMPLETE APPLICATIONS a
REQUIRE DOE TO PRIORITIZE PACKAGE REVIEW NEEDS
~
! -
- CONTRACT OUT FOR TECHNICAL ASSISTANCE FOR PACKAGE REVIEW.
- WOULD REQUIRE ADDITIONAL RESOURCES CONSIDER REPROGRAMING OF FTE'S IF POSSIBLE.
4 e S e 8 7
p i i e
SUMMARY
OF PHYSICAL PROTECTION REQUIREMENTS i
! CATI CAT 18 CAT 111 SPENT FUEL
[1] [2] [3] [4] i
~
- 1. ADVANCED ROUI C APf'%' OVA'. # #
d
~
- 2. ARMED ESCORTS #
- 3. ARMED ESCORTS IN URDAr4 AREAS /
l
- 4. COMuurdCATIO*J CENTER / CALL-afJS / #
- 5. ADVANCED LEA COOHDINATIOPJ # #
1 I
- 6. RADIO TELEPHONE /CB DACKUP j
\
- 7. SPECIALIZED CARGO VEHICLE # e
- 8. IMMODILIZATION OF CARGO VEHICLE # #
- 9. UNARMED ESCORT IN NOFJURBAN AREAS #
- 10. ADVANCED NOTrFICATIOtJ # # #
- 11. TRAINaf4G, PROCEDURES AND ttJSTRUCTIOtJS / /
- 12. NO CASUAL STOPS /SURVEILLAFJCE / #
- 13. PROTECTION ,OF SCHEDULitJG ltJFORMATIOrf / #
- 14. COtJVENTION NOTIFICATIOt3 # # # #
PeOTrs
- 1. WORC THAN S MGS OF teGHLY [NRICHf'D UR=Neuw (HEU) OR uORE THAN 2 eaGS Of" Pw. ~
- 2. 1 TO S FCs or HEU; SOO GRAan TO 1 p.C Pu
.3. 1* GRAMS TO 1 FG HCU; 1S TO SOO GRAuS Pw.
- 4. MOSFC YHAN 100 GRAMS Or IRRAD6ATED UNMMJU MEASURING 100 Rears AT THREC FECT UNSHuELDED 8
o ll L' 't EMERGENCY RESPONSE -ROLE OF THE NRC
- ASSURES THAT STATE AGENCIES, DOE AND OTHER AFFECTED AGENCIES ARE INFORMED OF THE ACCIDENT PROVIDES INFORMATION ON NRC-CERTIFIED PACKAGES OFFERS OTHER TECHNICAL ADVICE AS REQUESTED ONLY ASSUMES RADIOLOGICAL CONTROL OF THE INCIDENT SCENE UNTIL STATE OR LOCAL AUTHORITIES ARRIVE O
e
~
ADEQUACY OF REGULATIONS , 4
- COMMISSION REAFFIRMED ADEQUACY
] 4 (46 FR 21219) AS RESULT OF -i NUREG - 0170 I' l
- OFFICE OF TECHNOLOGY ASSESSMENT -
CONCLUDED REGULATIONS PROVIDED A HIGH LEVEL OF PUBLIC PROTECTION , 1. l
- FULL SCALE TEST RESULTS
- MODAL STUDY .
e u _ _ _ _ _ _ _ _ _ _ - _ - - - - - , - , - . - - .-----,-.--m - , - - - - - - - , - . - - ---y - , . - m,-- . , , -
W . i 1 1 l l I . ( - ISSUES ADDRESSED BY "MODAL STUDY" f l
- RELATIONSHIP BETWEEN EXISTING PERFORMANCE TESTS .
f AND REAL-WORLD ACCIDENT ENVIRONMENTS i . i CHARACTERIZATION OF POTENTIAL RADIOLOGICAL HAZARDS . WHICH COULD BE CAUSED BY LOW PROBABILITY SEVERE ACCIDENT EVENT e H ,
f . .. L r I { l. l SHIPPING PACKAGE (CASK) RESPONSE TO SEVERE HIGHWAY AND RAILROAD ACCIDENT CONDITIONS 1 i OVERALL OBJECTIVE EVALUATE THE LEVEL OF SAFETY PROVIDED FOR U.S. SHIPMENTS I~ OF COMMERCIALLY GENERATED SPENT FUEL - FOCUS ON TRANSPORTATION ACCIDENTS AND CONSIDER THE "NEAR FUTURE" INCREASES IN SPENT FUEL TRAFFIC. GENERAL APPROACH EVALUATE THE PERFORMANCE OF SPENT FUEL CASKS L! CENSED UNDER THE EXISTING REGULATORY REQUIREMENTS, WHEN SUBJECTED
. TO LOADINGS ASSOCIATED WITH TRANSPORTATION A CCIDENTS.
~
e 12-
Accident Scenarios l @ [.y" ~"'T
<~- n ,,
e "Soft" Tar t Vis a Vis Spent Fuel Cask h,; g[j.NG 'j !'- g.- [) l j 7 4 Mr gg bq . Cow,
--- W @ N " O- >@
i 1 l J 2
/ }
O & Cask Velocity
/
D _ _C_ _ - - _ . . __ _ -. 7 p ,... V 7 LJ l s 2."
# j u
. . 'e .
p ,
' ' , Su face.
j e Velocity - I' I j e impact Angle , Impact Velocity e Object Surface
% < a = impact Mgle
.
- No Fire or Fire
# = Cask Orientation Angle i
i j IU) J
! o Scal Area FJeutron sw S% . e speni rw , , , , Outer inner Shen I kV.th "
' Bolts ,
[ , _:771---
'- j _- _
- n_
_r:----r-I y y j
?. ..:r:.
~ '
-- < j . J ; J ,_ -- --
.~.
-. ' ' ~
s -~ < -.-._ _ s Q~7 -
, g = - - -
= ,__ _
1 u
\ \
\ Valve / Penetration ,
'S4$'7=
\ E negy %% Structure (Impact Lameterst Schematic of Skent -
Porsons Fuel Cask e O e a e e e
,/2 & .
1 Typical Radioactive Presumed if either:
. Material Release Pathway n) cask containment vessei strain between 0.2 and 30 percent, ,
or , (2) Centerline gamma shield temperature between 500oF and 1050cF l Gases, Vapors, and Aerosolized Particles to Cask Cavity Lower End Cap " ' ' #d #9 Seals A */
' If l Cladding l Pellets Gases, Vapors, .
and Aerosolized Neutron Shield P0rticles to the Environment Guter Sheti I Breach Gamma Shield r\
'l '- F/ . / t 1 (p .
. . . . ... . . )
&....... ~
/ j;.
r :
'.; Fuel ;
l l ,' l l y......................................,.. M . 1 7 r- '
' I r 1 1 _r 1 1 1 x r .-1 1 1 x . ,,,,,,1 1 _
\
T t I /ig .
]
Inner Shell ,- (Contammenti l i 1 I
~~ . . .
13 1
' . CASK CHARACTERI.STICS AND RESPONSES Typical Radiation Presumed if either:
Lovel increase as a ni cask containment vessei strain Result of Lead exceeds 0.2 percent, or (Gamma Shield) (2) centert;ne gamma shteid tiead) Slumping temperature exceeds 600*F
**l' Fuel Bundle , . .l.'..
void 3 . * *, ,* . . * *
..a,.
- i
( [ . ; *,* dr'ea's. of ! *.' . * .. s ; *, ,.
- Increased .*.
1 , ', ,. . . * . Radiation. * *, s . . . . Level .
. '. . ****..'<f.*,*
'ask i : -
l yCenterline Allowable Under p ! ! Accident Conditine.s glead Gamma
; c Shield increasing g
Radiation
' !i rCask Containment N levels As Void Shell i 8 -
(Lead Slump)
- Increases )
3
# i 1 \
l a
. a= \ '
y Normal
\
j . l \ Distance From Cask
! (log t ,
=
l l I
. Y w-_-__ m _._ ,mm. -. .- ,__ ,.. _, _ , ._
. 1
. 1 Cask Response .
. i (Damage) Regions l
["'
""hDdMAC E $bT RSYD .. .
x .. .
} . & $ ,,4 I
emE 1 (3.1) M AJ D 'R (3,2) (3,h R (3,4)
!'CD,- -
8 4 ,, o% x, . . Q _ ; .-
) c'jp', s .
H j mg MINOR12,1) R Sr T b,2). 9' R(2.3) 3* b R (2,4) <.4
,y
& )/
plyj li t' ' .> f:pf4 r1 -
. . m ., F.
llE 0.2 . . . . . , . . . , = s .. . SNatsbV W
~ *
.2 a NR( f- -
R (1,3) R(1,4) e,'.
) ,
/; ,,
r., s.
/. I
, d4'.f F fi.'
. l
< . ,. i. : x (- .
/.TTI / , - ,r /
500 600 650 1050 l Thermal Response, 'F
. (Centertine Lead Temperaturel '
l l SUPERFICIAt. DAM AGE MAJOR DAMAGE.
$ , ll MINOR DAMAGE DAMAGE EXCEEDING DEFINABLE RANGES
"'** . - hm 1m M.4 merge. m ,=.;-- -
1 THREE PERSPECTIVES PROVIDED BY i MODAL STUDY RESULTS
. i k' -
l ACCIDENT LIKELlHOODS PRESENTED IN TERMS WHICH - ,' COMPARE POTENTIAL FOR A RADIOLOGICAL HAZARD TO , VALUES SPECIFIED IN CURRENT PACKAGE ACCEPTANCE CRITERIA TOTAL ANNUAL ACCIDE T RISK PROBABLE RESPONSE OF REPRESENTATIVE CASKS TO ' SEVERE ACCIDENTS ON RECORD i i 16
~ - - - - - - - - - -- - - - - ----- -------
1 i * . l
.' l I
My. e . 9 Accidents With No 'W Ds Expected Radiological ,T 6% D I Hazards 7 < a [b"['IW m
?
, )
I l 7 ( .
~'
i
- , . _f 2 Oh :
.y (oIOf dOO O -
N950 of Every 1000 Accidents o "Soft" Target Vis-a Vis ' i Spent Fuel Cask O No Fire or Fire of ir Either Umited Ext 1nt, Temperature, or Duration
;d O - --- g 1 a
J Cask Velocity i /
'1C /h,:.,
a_- . V
./ .s I
Q # . [. .' O
- T ,;. -
N44 of Remaining 50 '
)\.......
Accident:: . - -
- One or More of the
. Object ..
- Follow;ng Apply:
1
- .. *;i. Surf ace.
I oVelocity Too Low ..,' J.'J '. i i o imp' act Angle Too . - Shallow o impact Velocit'y o Object Surface Too Soft
- l o No Fire or Fire of ,
g< a = Impact Angle '. 1 Either Limited Extent, i j Temperature, or Duration # = Cask Orie'ntation Angle 4 l
Conclusion:
I 994 of Every 1000 Truck ! l Accidants Generate Forces I Incapable of Causing Cask Functional Damage. l l 1 1 { 17 i
9 li .. 1 i Fraction of Truck Accidents . Involving Spent Fuel Shipments that Cause Cask Responses Within Each Response 1 Region -
)
S3 ) ) J
=f T oubnd wLess Than 1 per Million ry 7 l eg ( All Boues) si 2 l S Si ac" .r Ej g (0.2) b ~2 N2
- d N994 per per 100 per 100 l Thousand Thousand Thousand ( .
0- -- A Ti T2 T3 T4 l (5001 (600) (650) (1050) l THERMAL RESPONSE. 'F l (Centerline Lead Temperature) l l t e k
.s -+m-- -
i - ) I I i Predicted Cask Response to , ! Selected Historical Accident 4 Events I Pr: dict.+d Cesk Response 180 BRIDGE ACCIDENT 3/81 C ALDECOTT TUNNEL FIRF . 4/22
- No Significant impact Damage -
- Co:lissn With Pickup Truck i
- 3 Vehicle Cottision - Gasoline and Fall from FA. Foot High Truck Trailer, Bus and ** Soft" Objects j Bridge Onto Soil Automobi's
- 45 Minutes ' 1900'F Causes 500'F
- G,200 Gattons of Gasohne Centeriine Temperature Predicted Cask Response l
- Fire of 2 Hours and 42 Minutes *
- 44 mph Impact l 40 Minutes
- 1900*F . No 3;gnificant impact Damage 1
l t *
~ LIVINGSTON TRAIN FIRE v/C2 i =
- Deraament of Vingt Chloride /
l s 30 g r Petroleum Tenk Cars 1 i a M [
- Large Fires for Seversi Days Moved Over Large Area' i U
- 2 Esplosions
~ h j Predicted Cask Response 8 Ff P [
- Maximum Probable Cask Esposure to Petro <eum Fim Between j
82 Hours and 4 Days . e l HARD SURF, ACE j
- E, cp,8[d'"' D'** 2' "*
- Centerhne Shield Temocrature 6
. r
/
If F f Between E00*F and 7MF l
)
" /. I
- Ocpendent on Degree of
\ D i
l ACE Vffff I f ff f YA C* 'a v '"'"' I a l I O SCO 600 650 10f.O Centerline Lead Temperature l'F) DERAILMENT ON ALAR AM A RIVER BRIDGL' 1/79
- Plunge OM 75 Fbst High Bridge
- Railcar impacts into Water
- and Mud No Rad.ological Hararo Radiological Hazard Rad.ological Hasard Predicted Cask Response
- Appro uimates Eacceds Compi.ance Comphance Values
- Values By Up to a
- 47 mph impact in Soft laget Factor of 4
- No Swgn.t. cant Impact Oamage i 1
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4 ~ - . fu 50 .. R . .?.'9ndrs@t.,s ,ALML. .,@ALL-s.- FES LLNL STUDY (N U R EG-0170) R ESU LTS ESTIMATES Fraction.of Transportation Accidents involving Spent 0.09 (Truck) 0.006 (Truck) Fuel Shipments Causing 0.20 (Rail) 0.006 (Rail) Any Radiological Hazard i Fraction of Transportation Accidents involving Spent 0.004 (Truck) 0.00001 (Truck) Fuel Shipments Causing 0.002 (Rail.) 0.00013 (Rail) Largest Estimated Radiological Hazard 1 i l Overall Annual Risk 0.0004 Less Than 1/3 i From Transportation Latent Cancer of FES Value Accidents involving Fatalities Per Year Spent Fuel Shipments l, P l
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O . NEW ISSUES . i -; l
- NODULAR CAST IRON a r
- RECTANGULAR SHIPPING CASKS :
- CREDIT FOR FUEL BURNUP l
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;. NRC TRANSPORTATION EVENT RESPONSE mounce. sacronrau_te evewr oseensenone comestro er aeoc rom seve-sees i
1985 : AEOD CHARACTERIZED 25 EVENTS AS TRANSPORTATION RELATED: 9 INVOLVED VEHICLE ACCIDENTS - OTHERS INCLUDED HANDLING DAMAGE, LEAKING PACKAGES, ETC. t OF 25 EVENTS, 4 INVOLVED MATERIAL RELEASE: NRC (REGION IV) RESPONDED TO ONLY ONE (YELLOW CAKE TRUCK COLLISION WITH TRAIN IN NOR'TH DAKOTA) - 1988 : 33 TRANSPORTATION EVENTS: 9 VEHICLE ACCIDENTS, 4 INVOLVED 1 PACKAGES FALLING FROM VEHICLES, OTHERS INCLUDED HANDLING . DAMAGE, THEFT OF VEHICLES, ETC.
- OF 33 EVENTS, 4 INVCLVED MATERIAL RELEASE: NRC DID NOT RESPOND TO INY OF THESE EVENTS
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' .* * ,t [ [ ADEOUACY OF REGULATIONS f ). . i OFFICE OF TEClitlOLOGY ASSESSMENT REPORT ~ i . i I i' '
- EXAMINED TRANSPORTATIOl1 OF HAZARDOUS MATERIAL s
I
- CONCLUSIONS ON SPENT FUEL TRANSPORT : .
i \ j " NRC PERFORMANCE STANDARDS YIELD CASK DESIGN f , . SPECIFICATIONS THAT PROVIDE A HIGH LEVEL OF - ! PUBLIC PROTECTION, MUCH GREATER THAN AFFORDED [ IN ANY OTHER HAZARDOUS MATERIAL SHIPPING ! AC'fiVITY.
" THE PROBABILITY OF AN ACCIDENT SEVERE ENOUGH TO CAUSE EXTENSIVE DAMAGE CAUSED BY RADIOLOGICAL
~
RELEASE FROM A PROPERLY CONSTRUCTED CASK IS I EXTREMELY REMOTE. " _ _ _ - - - - _ _ - - - - - - , - - - - - ---,-m.m --ee-3v- .--%-+------ =---+--------e-- * - -r--------- - - - - - - - - - - - - - < -
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r i ADEQUACY OF REGULATIONS
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NUREG - O170 l BASED ON: - i
- IN FORMATION DEVELOPED q
- PUBLIC COMMENT RECEIVED
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- SAFETY RECORD THE COMMISSlON CONCLUDED THAT: i PRESENT REGULATION PROVIDES A REASONABLE DEGREE OF SAFETY AND THAT NO IMM EDIATE CHANGES ARE NEEDED TO IMPROVE SAFETY . -
(46 FR 21219) e l e
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FROM: SECY Correspondence & Records Branch
! Attached are copies of a Commission meeting transcript and related meeting ll docurent(s). They are being forwarded for entry on the Daily Accession List and lj placement in the Public Document Room. No other distribution is requested or l
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= i s Mihhhhhhhhhhhhi1hhhhhhhhhhhi$hhhhhhhhhh E M M
g U.S. NUCLEAR Transporting Spent Fuel Protection Provided Against Severe SSE^s's?s! Highway and Railroad Accidents e
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l(h/) - Protection Provided AgainSt Severe Highway and Railroad , j U.S. NUCLEAR Accidents
- f REGULATORY '
' COMMISSION March 1987 1 ; Author: William R. Lahs t
/ l' D'rvtsion of Regulatory App!' cat'ons Office of Nuclear Regulatory Research !
) U.S. Nuclear Regulatory Commission .
j j Washington, D.C. 20555 l i l 1 [ t TABLE OF CONTENTS i l 1 Overview Page Page ! l Introductsn 1 Typical Radioactive Material l Accidents With No Espected Release Pathway (dustration/ , . . . 17 , j Radiological Hazards Mustrationl . 2 Typical Radiatsn Lewel increase l 1 Summary of Otiectise and ResuMs. 3 as a Result of Lead (Gamma Shield) y
*EN ### * ' ' '
I l Bac kground . 3 as amage - Mat AccMent J I How is Safety Achieved? . 4 Conditions Are important ; i i Standards for Spent Fuel Casks 5 and How Are They Defined? . . . 20 l Accident Scenarbs 6 ; l Occurrence Rates for Truck Accamt Scmares Muneston/ 7 , Potential Hazards and Risk Occurrence Rates for Radroad i Accident Scenarnas Mustraron/ . 9 Fraction of Accidents Wahout > j Enpected Radrological Hazards . 22 l 1 Accident Scenanos Generating l f Cesk Characteristics and Responses Mechanical Fore.es Incapatdo , of Causing Functional Cask j
! Can Cask Safety Be Chiracterized Damage Mustratenl . . 23 j in Real-World Acc4ents? . 10 ,
Accident Scenarios Generating l Representative Des gns for Thermal Forces incapave , Truck and Rad Casks Mustratoni. 10 of Cauong Functonal Cask i
! Schematic of Spent Fuel Cask Mustratwn/ 11 Damage wastraten/ , , , 25 Cask Ssfety Functions and Potenttat Ridiolog1 cal Hazards l Representatne Cask Design Features. 11 Resulting From Functsnal '
! EstatAshing a Scale to Cask Damage . , 26 Measure Cask Response. 13 I Fracten of Truck and Ra t Accidents Measure of Cask and Spent Fuel insotong Spent Fuel Shipments That ! Responsa to: Mechanical Loads Cause Cask Responses With4n j ) and Thermal Loads /2 avstrat,onsl. 14 Each Response Reg.on Mustraronl . 27 , I l Evaluating Cask and Spent Fuel interpretation of the Re!stonship , Response to Accident Los:!s . 15 Between PoteMial Radiological Hazards f Cask Response (Damage) and Real-World Severe Accdents , , 28 7 Regens Mustration/ . . 15 Risk Estimate for Spent Fuel Sh;pnients . ,, ;$ l l Re'atonships Between Cask Response Risk Rcaults Comparison With j j and Potential Rad.olog; cal Hazards . 16 Past FES Evaluaton Mustraten/ . 30 l 2 i [
OVERVIEW and <23 assure that the spent fuei radioiogicai risi from transporta-INTRODUCTION will remain subcritical (that is will tion accidents. Nisk represents the I not undergo a self sustaining summation of the products of the 4 nuclear reacton). magnitude and I;ketbood of all ac. This report summarizes the results cident outcomes. The purpose for of a study conducted for the The study, conducted by making the risk calculations was Nuclear Regulatory Commission Lawrence Livermore National to compare the resulting values (NAC) to determine the level of Laboratory (LLNLL' began with with those previously used by safety provided during shipments an assessment of the possible NRC in judging the adequacy of of spent fuel from U.S commercial mechanical and/or thermal forces its regulations. nuclear power plants. The study generated by actual truck and focuses on the protection provided railroad transportation accidents. The purpose of this summary, for shipments that may be in- The magnitudes of forces from ac- prepared by the NRC staff, is to volved in truck or railroad tual accdents were compared with present the results of the LLNL accidents, forces attnbuted to the "regula- study to a broad range of readem tory <!efined" hmothetical accident who may possess varying degrees During shipment, the cask and the conditions. The frequency of the of knowtedge on the technical l form and structure of the spent accidents that can produce de- subjects covered in the LLNL fuel being shipped provide the fined levels of thermal or mech- technical report. As a resutt, this primary phnical means for con- anical forces was also oesetoped. Summary focuses on the overall ' I taining radioactivity and for With this information, the study approach and major results of the limiting radiaton levels outside the results show that for certain broad study. Atthough this summary
) classes c f accidents, spent fuel describes many important assump-j cesk. These functons must be m.:intained at acceptable levels casks provide essentially complete tions and insights, a complete j cven under the wide range of protection against radiological understanding of the scope and hazards. For entremety severe ac- meaning of the LLNL work wouM forces the cask and fuel could be subjected to during an accident. cidents, those that could con- require, as a minimum, frequent ceivably impota forces on the cask reference to the main LLNL report Spent fuel tipments are regu- greater than those implied by the and its supporting appendices.
I lated by both the Departmerit of hpothetical accident cond, tons, 1 Tecnsportation (DOT) and tre the L.kethcod and magnitude of For the reader interested sole!v ist NRC, The NRC ewaluates and cer- any rad 4ological hazard were con- the resa'ts of the LLNL study, the l i tif>es the design of the shipping serNathety calculitsd. The study fquie on the nemt page, the foldout j ccs s used to transport spent fuel, also contains an evaluation of the on page 29, and the discussaon ' while DOT regulates sehicks and unde "Summary of Obje:the and I i dnvers. - Results" should be r,onsutted. l ' Readers w,shing to understand the
- snwng contm< Rew.e to swo s Current NRC regulations require 9. , ya pg.., Awte gog;g n, the approach and the basis i that sh ppeg casks meet certain Numic cm An reuw, tw Th* for major assumptions should refer 1 performance standards. The per- 'Wt N** W'h*ab"* to the main t.cdy of this summary i formance standards inchide normal *'[ ,7$$ , ,eport, which presents a step by- 1 i
operat;ng cond. tons and hmo- y ,y,,. ,,, , m ,, www ns step emplanation of the separate I l thetical accident conditions a cask cw,vg at e,. Nec Nac Cw.n' tasks required to meet the study's I must be capab4 of withstandog mm 1717 H 5troiet. NW. w unrste. c @ tnes. < without eiceed.ng specified ac. O C. Fewm.al NRC reps are 4,640, br
#" W "* N**"** #
r c*Ptance criteria that II) inut Cw m ts.us G wnme P.w gCd i releases of radioactive matenal and rce. peg, o%, gn pyy wump rad.aton levels outtede the cask oc nu w 1 i 1
i OVERVIEW
-.3 Accidents With No 4 l Expected Radiological Hazards t
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_a l (oJyp f07 @ h. 0 y-- 2 ' O i O N 950 of Every 1000 Accidents xG,\s. ['N, , e "Soft" Target Vis a Vis NA%* i Spent Fuel Cask o No Fire or Fire of "m DI *~ i Either Limited Extent. Temperature, or Duration %w - -~-^ g - i Cask Velocity y
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' Impact Velocity e No Fire or Fire of \ g'
, < a = lmpact Angle Either Umited Estent, j Temperature, or Duration f = Cask Orientation Angle i
Conclusion:
994 of Every 1000 Truck Accidents Generate Forces Incapable of Causin
; Functional Damage,g Cask t
2 i
OVERVIEW
\
Summary of Objective led to the finding that in about 1 BACKGROUND in 100,000 tru k a cidents and i in cnd Results 10,000 rail accidents, extensive damage to cask and fuel could oc- Over the last 10 years, thousands cur. In these situasns, engineer- of shipments of commercially The objective of this study was to ing judgment was usedto conser- generated spent nuclear fuel have characterize the level of safety for been made thmughout the United vatively estimate the resulting commercial spent nuclear fuel radiological hazard; however, States without causing any ad-shipments should they recome in- predictions made under such verse radiological consequence to volved in severe transportation ac- members of the public. In the near unlikely accident conditions are cidents. Researchers evaluated a subject to uncertainty. future, the number of these broad spectrum of severe, his, shipments is expe<..ed to increase, torica?ly documented, truck and More than 40,000 spent fuel rail accidents that caused death, In an attempt to gauge thia uncer. tainty, the stuJy assessed the assemblies have been used at injury, or significant property nuclear power plants in the United damage and assessed the minimal potential for a radiological hazard in extrer9ly severe accidents by States and are currently being level of performance that should stored in underwater "fuel pools" be achieved by NRC-licensed assuming that a spent fuel shipping cask with minimally acceptatWe at these sites. Under the terms of spent fuel shipping casks. The the Nuclear Waste Policy Act results, illustrated in the figure on capabilities was involved in the four documented severe accidents (NWPA) of 1982, these spent fuel the opposite page, indicate that assemblies will be placed in a no radiological hazard would be shown on page 29. The most likely outcome in three of these four Federal Repository for permanent expected irt at least 994 of every storage beginn!ng in 1998, 1000 severe transportation act). accidents would be minur or super-ficial damage to the cask and no Shipments from reactor sites to dents, in only about one acci. the Repository for ultimate disposi-dent eve'y 40 miflion shipme'it radiological hazard, in the fou th, and under some circumstances in tion will require increased rail and miles for once every 13 year's road movement of spent fuel. assuming 3 million shipment miles two of the three previous accidents, per year) would minor funcfional a radiological hazard could occur. its magnitude would be less than or in part, because of the projected cask damage be expected, if any increase in the number of spent radiologhal hazards were created, comparable to the hazard implied by compKance values in existing fuel shipments, the U.6, .'Juclear their magnitude would be expscted Regulatory Commission (NRC) to be less than currently-defined NRC regulations. decided to reassess the level of compliance values in exis'ing safety provided by casks designed regulation. In only about one acci- As a final ooint of reference, the to exis%g regulations. dent evvy 80 million shipment risk of spent fuel shipments was miles could cask damago be evaluated and compared with in !arge measure, the safety s'gnificant enough to cause a previous estimates used in assess, associated with spent fuel radiological hazard whir.h could ing the adequacy of existing shipments, especially in the event l equal or slightly exceed existing regulations. The resulting risk level of a transportation accident, is compliance values. was less than one third of past estimates, provided by the casks that contain the spent fuel during shipment. '
- The data from docurrented severe These casks must meet perform-accidents had to be extrapolated ance requirements specified in the ,
to characterize extremely severe Code of Federal Regulations (10 s accidents for which enperience CFR 71) and their design must be provided no models. This process certified by the U.S. Nuclear Regulatory Commission. l 3
. _ _ _ _ . _ . _ _ , , . . _ . , _ , ~
OVERVIEW
~
Other elements of safety are pro- ErileeNih'eMieI[This 'meieirib These acceptance criteria include: l vided by the Department of ,is normally contamed within the~ .l (1) stringent limits on both the Transportation's operating require. metal fuel rods that outround the ~ ) maximum allowable release of ments for vehicles and drivers. pellets. .i radioactive material and the radia-These operating requirements are . l tion levels outside of a cask and defined under Title 49 of the Code ,The heet and radioectMty in spr,t j (2) requirements regarding cask of Federal Regulations, fuel necessitsees that any ship-W 1 configurations which assure that
, ment be made in containers or j subcriticality of the spent fuel is
, . _ - - . -e.- ._ _
casks that provide the necessary 3 maintained.
- What is Spent Nuclearj degree f public protection. in j
- practice, this meene a cask must j in practice, NRC verifies con.
, Fuel.? i formance with these acceptance
' "_ ahield and contain the radioactiwty j
.4 [ and deceipote the generated heet. '
criteria by analyses demonstrat;ng Spent nuclear fuel refers to i that essentially no permanent
,0ranium-boating fuel elemants that j deformations or excessive temp-have been used et commercial How is Safety eratures occur within a cask's con-nocloor power reactors. This spent i Achieved 7 tainment shell following the (used) fuel contains radioactive d sequentially applied load,ngs i im-a posed by hypothetical accident material process that resulting takes from placethe fission within the ! Safety in the shipment of spent conditions. Demonstrations that reactor. The radioactive material is ] nuclear fuel is achieved by a com- casks can withstand these condi-formed within ceramic fuel pellets i '
bination of factors including the tions, coupled with information
.about the diameter of an aspirin phs<sical properties of the spent about cask designs and construc-
- tablet but twice as thick. These j fuel itself, the ruggedness of the tion materials, suggests that casks
'penets are contained in 15-foot. j container or cask containing the s.l ould be capable of withstanding long sealed metal tubes or rods-a j fuel, and the operating procedures far greater mechanical and thermal few hundred per ro'd. From about i and controls applicable to both the load:ngs during an accident than C ) to 400 of these rods are , cask and the vehicle transporting those caused by hypcthetical acci- "grouped in a square array to '. form ! the cask. If a transportation acci- dent conditions without causing a spe6t fuel assembly. j dent should occur, safety is any Wgnificant radiological hazard.
L ,k 4 primarily assured by the integrity The LLNL quantifies this capability iWhen ap'ent fuelis removed from ' of the spent fuel shipping cask, through two supporting analytical
- the reactor, the self sustaining i The design of all casks used to assessments. The first identifies lfissico process has tcpppd;
{ ship commerclaHy generated fuel actual documented accidents in
'however, spent fuefatat 4Ees ' ' - in the United States must meet which mechanical and thermal s1 generate significant wr60unts j performance oriented requirements loads would be less than those im-of radiation and heet. This heat j specified in Federal and interna. plied by the hypothetical accident 'and radiation are caused by the '
tional regulations. The perform. conditions. The second identifies
!"sedioactive decay" of the pro.- , ance requirements include the accidents (and their likelihood of 1 ' ducts of the fission process. The . j definition of a series of "hypo- occurrence) in which loads could l f actual material emitting the radia, j thetical accident conditions," exceed those specified in the l , tion is, for the most part, still coni described on the opposite page, regulations and evaluates the 'tained within the ceramic fatal s ! All licensed casks must be capable capability of a cask to continue to ! pellet. Some material, however, .
of withstanding the mechanical function safely under such mainly in gaseous or vc',etile form, j and thermal loadings imposed by conditions. I these conditions and still meet specH.ed acceptance criteria. 4 ;
OVERVIEW l l l 1 r ~ l Insights on the safety. , .,-,, ~ec, ~4 Standards for Spent . Fuel Casks !Provided by Typical Spent j i l o (FueP; Shipping Cesks ! l For certification by the NRC, a yggg g h]h I cask must be shown by test or [ and 6 Q' hoe h W W d analysis to withstand a series of !e accident conditions. These conde.- fW by A @ he h W N g, tions have been internationally ac- spent fuel % -! cepted as simulating damage to icasks; h mon drm i spent fuel casks that could occur ih has W M .i in most severe credible accidents. M mom W out both h 9'h } The impact, fire, and water- W h h Bituin. . . , l Immersion tests are considered in 3 g ,g , eg,g, sequence to determine their
, h b e W-on hm . !
cumulative effects on one pack- lrnesche concrete borners at i age. A separate cask is subjected ! M h 60 to w W mph. I o o to a deep water-immersion test. 5 Casks have also been struck by - The details of the tests are as flocomotwee traveinng at 100 mph !
*8 - ;and have been immersed in fires !*
n } in wh;ch temperatures have been h* (deliberstely kept high. In d tests, ; impact ,the rmiting cad demeos ranged i i from superficial to very minor, i Free Drop (a) - The cask drops 30 lThese roeutts certainly.etteet to , feet onto a flat, horizontal, unyielding j the well g;tz W the i surface so that it strikes at its i casks tested and the general in- a f weakest point. of their design. From an la@nalytmel standpoint, the most
.j Duncture (b) - The cask drops 40 ;noteb6e & to provide insighte j ,
o o inches onto e 64nch-diameter steel into the sekty of spent W f
, k ! shipments hvadved the properation <4 g () bar at least 8 inches long; the bar strikes the cask at its most vulnera. !of a genene htal m j C. w spot, ! ment on the shipment of d ; ,
i redlooceve motoriolo, inclueng l i spent hsel.' This study inceuded j Fire (c) j en evaluation of the fleks from 3
- After the Impact tests, the cask is [ g_ . _ TEM W iehvoiWho i; 4
totally engulfed in a 1,759 environment for 30 minutes. thermal i g ,, mhtg, IN k a 6 _f Water immersion (d) !" t Wl The cask is completely submerged i ~!
~
under at least 3 feet of water for 8 7 hours. A separate cask is completely
'mmer$ed unde' 50 feat of **t for
{*m &W m $
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_ 8 hours. to m .a m % ~ - oim.-.j Io.cenhw ton. ,. i ' 5 l
OVERVIEW t l 4 4 j the potential effects of cask im. The historical data also provided i . o V % W, *q" .y,
,s N N 'Tg pacts with a variety of hard ob- the basis for developing speed p ..:..i . jects or surfaces. Impacts with
'~ -- --
. O. hQ distributions typical of the acci-c t 2 - ' -
these types of objects or surfaces dents (see the figure on this page). A .
- 'y* '
have the greatest potential for causing damage. The extrapolation The speed distributions were
,' "g was made by merging docu- based on (U estimated vehicle i *s: g * . - -
. j 49 mented accident data with statis- speeds at time of i.mpact; f- .
p 1" j e' - m.
. i . <-M. tical data representing highway (2) speeds attained in falls (where terrain and adjacent structures. fall heights were calculated from a p . " . . .- ...4.- 7; This data was obtained from survey of bridge heights along in-
- p. r.
. f, ,
,, . , . . . . .. J' - recorded information and by terstate highways); or (3) combi-J . . .
- ) surveying hundreds of miles of nations of these speeds. Fo. the m e . .
. .g. j. . w y br~ s typical interstate highway to deter- truck train scenario, the train f,.s. .y . o . . y g,;. ..
3 y. mine how frequently surfaces and speed distribution reflects the ag2%9.dd@ G g objects such as large bridge col- historical data applicable to grade-umns or hard rock surfaces occur. crossing accidents. 1 Most spent fuel shipments will be Accident Scenarios made over such interstates. Historical data on accident-related fires was limited to statements of Spent fuel shipments could be whether or not a fire occurred. In-subjected to a variety of trans- formation on the duration and portation accident situations of temperatures of fires, and of their TRUCK ACCIDENT SPEEDS location with respect to a vehicle's scenarios. Identifying these poten-tial scenarios began with the cargo was extremely sparse As a historical data from typical truck result, the environments typical of accidents that involved deaths and 1.0 accident related fires had to be injuries or those that exceeded assessed through an engineering certain levels of property damage. t model. This model is discussed in
, Q,Qa ghway the folloWing seClion on railroad Data from minor accidents (e.g., T object Impacts accident scenarios, fender benders) were excluded. & /
Highway v, f 3* i Most of the information on the Q 5 likelihood of single and multL #g 05 5 J vehicle accidents in the Cgure on M i the opposite page is based on
- 5 historical data. The solid lines show accident scenarios derived g /
4pkabie a from the historical data whereas to Fau the dashed extrapolations consider "' 9 h 10 30 so .j S(mph) { l l i 6
OVERVIEW Occurrence Rates for t aound d aiu.. Truck Accident
- Accident **au. aces sub**au ativ shown to have the most likely Scenar,os i po..ibirity or c.u.ing e..k d.m.a.
um Dev. loped ext.nsions of historical
.cenario data .
OCCUmmENCES Pta Fxe ACCIDf NYSt INDEX g.a.<m em---~,_ 3 ~ u ,
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OVERVIEW Occurrence Rates for t nounded vaiue. Railroad Accident accia.nt ..qu.nc. .ub..qu.ntiv shown to have the most likely SCOnarlOS poulbluty of causing cask demoge mmDeveloped extensions of historical scenado dets occo... css AC 8 Si see gg =
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CASK CHARACTERISTICS AND RESPONSES Representative Designs for Truck and Rail Casks Pseutron sh.eks 13 (Diamete of Cavid gg g,,, _k 7 0 -4 p-- '
- -** ! b 7 0 inic- e -
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{ ; -- Can Cask Safety Be 1 _ n > Characterized _ I sn% ' 4 s t,o f I in Real World a- wem l l "
-l l
Accidents? 'O., 22 g , ,n coctects 250 m u) TRUCK CASK This question was critical to the credibility of the LLNL stud) The , ,_J l_ I answer was "Yes." An approach ,, lI 40 % _ ; C,40_. to the problem could be followed ,,,,{ ,,, , , g, g , ,, , i to allot. fair chsracterization of the jj ": ' i i
^
minimal level of safety that would "'
.;.. t i j i 6 j
be meaningful to an assessment of ; .jj; E 85 5,,ly,y,, the adequacy of existing regulatory * * " * ,
!. of cwo r:auirements. The first step taken - r*" inicu : r =
in this approach was to define two --
'w ;
a representative cask designs-one q _. , l , for truck shipments and one for , , _ ,, , j j rail shipments in both cases, the casks were designed to just meet 8* tu C + m ! t~. n sm -
"regulatory" acceptance criteria c-wi ,,s2w following an accident with mech, th u Ran cask cnical, thermal, and water.
immersion accident conditions depicted on page 5. The cask designs included only those features absolutely necessary to $*'*,,,,nentative truck and rail c-eske l determine a cask's ability to ^8 * **'" * " conelet of steinine steel cyundrical achieve its primary safety func- ' , *,, 5: t7' SW eheHe that enclose a ring of lead tions. (These safety functions and H ,o w ee., *hidia8 **'*'i'l A * * l'c k 'u r-the cask features that achieve ""d* 'hl* ' Y"" d d* *' " * '"'
- A '
these functions are discussed briefly each end of the cask, art impact umiter 'le provided to protect the cask on pages 11 through 13.) ogainst impact forces. l 1 1 10
CASK CHARACTERISTICS AND RESPONSES 1 l l Once these representative cask Cask Safety Functions the cask cavity and the environ-designs were defined, they were ment that prevents leakage. Piping subjected to the most damaging and Representatjve penetrations, which terminate in Occident scenarios identified on Cask Design Features protected enclosures, are also pro-pages 6 through 9 to determine vided for operational purposes. their structural response. By The required containment safety The primary cask safety funct. ions function is achieved by these measuring structural response, researchers estimated their poten- include: (1) containment of . fea+ures. Furthermore, the suc-radioactive material, (2) shielding cessful functioning of these tial for a radiological hazard. If the potential existed, the magnitude of against the radiation emanating features is promoted by (1) an ex-the radiological hazard was con- from the spent fuel, and (3) as- ternally located, energy absorbing surance that subcriticality of the structure designed to protect the servatively evaluated. Through this process, that fraction of severe rail fuel is maintained. cask against impacts, and (2) the and truck accidents capable of . integration of the containment causing a specified radiological Containment .is ach.ieved by retajn- features into an overall cask hazard was estimated. The ing the radioactive material with(n design that maximizes protection radiological hazard was then com- a closed vessel. Typically, contain- provided against outside forces, in pared with compliance criteria in ment is provided by the integrity defining a representative cask, the existing NRC regulations, f the spent fuel cladding and by complexities associated with the cylindrical steel containment various designs for containment As an additional point of vessel or inner cask shell (see closures, penetrations, and seals reference, the radiological risk of figure below). The vessel is pro- were not modeled. The failure of shipping commercial spent fuel vided with a bolted-end closure to these features was assumed if the was compared to documented permit loading and unloading. The containment or inner shell was estimates used by the NRC in closure contains a seal between calculated to incur any significant { making its past judgment on the permanent structural damage, adequacy of existing regulations (see insert on page 5). s .i Ar,.
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Fuel 8.noet * Schematic of Spent R'L?,'"*" 0"
# EiU.? *'
Fuel Cask 11
CASK CHARACTERISTICS ! AND RESPONSES l 4^ Shielding is provided against regulatory limits for transportation structural materials. The "poisons" gamma and neutron radiation, accidents. Failure of the neutron are typically included in the solid Protection against gamma radia- shield was assumed to occur for structure or "basket" holding the j Hon which is very penetrating is all accidents considered in this fuel assemblies and absorb emitted most important and is achieved study. As a result, only the lead neutrons, thereby making a "chain through use of heavy materials gamma shield was modeled in reaction" impossible and thus such as lead, uranium, or steel some detail in the representativo assuring subcriticality. Before the i that reduce the radiation levei. cask designs, fuel basket can incur any signifi-l This material surrounds the con- cant damage, the total cask struc-i tainment vessel as seen in the M '~ ture, including the containment schematic on page 11. Protection
! against neutron radiation is often provided by water, which typically
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i l A spent fuel cask being loaded on e
; truck-front end impact limiter shown l st right of truck.
1 i Suberiticality is assured by either Note: 1 fills a jacket surrounding the main limiting the amount of spent fuel Actuel spent fuel casks hke the one cask body. Loss of the neutron being shipped or by maintaining shown in this figure are espected to
- shield normally results in a small control of the spent fuel confi, ['n' ar'hj'id'" n"d 'V'"
c e than increase in external radiation guration during shipment and in- representative cask designe essessed in levds, but to a value that is within ciuding "neutron poisons" in cask this study.
=
12 _ ___ .___,_ _ . . . . , - _ _ ~ _ _ . , _ _ , _ , _ - - _ _ - _ . ..____ _ . _ _ _ ...-_ .. ______ __ . - _ - _
CASK CHARACTERISTICS AND RESPONSES shell, would have to be severely ' Severe occedents typicesy enwohre l rupture of the cask. The most damaged. However, physical impacts with messive end heed ul>- common engineering guidelines damage alone does not affect a used to characterize structural j cask's ability to maintain sub. f jocts.or surfaces or empooues to, n]} l hightemperstisse fises of len0 ' damage are stress, strain and critical conditions. A material like dureden. The scenerlos shown on ~g displacement. Strain, particularly water must surround the cask and pages 7 and 3 ese 9 tees tiet . on the inner "containment" shell fill the area between individual fuel could comprenelse e caelt's seletV l 3} of tne cask, was selected as the i rods and fuel assemblies before { functions and potendeSy cause a . I ' best single indicator to charac-criticality would be possible. For i radiological hoseed terize cask damage following a these reasons, the features to transportation accMent. Sensitivity assure subcriticality are not speci. lGsvest 3 the rug 9edness and massiveO studies established a relationship fically modeled in the represen. nous of opent fuel cashs, a seve'e " between the strains at different tative cask designs. Instead, an s occident in this study wouki not cask locations and the maximum upper bound estimate of the iinclude tragedes involving coNisions ,; strains experienced in the cask likehhood of criticality is provided { between the vehicle trenoporting containment shell. As a ruult, it in the LLNL report. The estimate (the cask and an automobile or bus i was possible to use a specific is based on the typ6 of accident (in which several people might be i strain in the cask shell to estimate that could substantially deform a killed or injured. Although potential- 1 damage to cask coraponents such cask in the presence of a material, ;ly
' serious to the occupents of such as seals, closures, and like water, that would promote l vehicles, collisions with automobila I penetrations.
critica:ity. A brief discussion of jand buses at er}y speed involve ; this estimate is presented in the , forces that would not seriously Three discrete levels of strain were section on potential hazards and : compromise cask safety functions. defined to encompass four broad risks on page 26. [ Any deaths or injuries frorf t such ranges of cask and fuel damage, pccidents would not be caused bY as shown in the figure on the
;the radioactivity of the spent fuel following page. The significance of
*f90- the 0.2, 2, and 30-percent strain 7
_ ~ , . _
,,,,,,, in ,,,m, g,n,,,,,y ,n g;c, t;v, of cask and fuel damage, is also lWhat Constitutes a
- Severe Transportation illustrated on page 14.
I Accident 7 [ Establishing a Scale to this study, a severe accident is Moasuro Cask l one that could comptomeee orw of ' L'hree besic cask safety functions: Rosponso
,(1) any fo9s of containment of ' spent fu*3 material. (2) a doerade 4 Mechanical Loads-tion or mduction in cask sheiding j Measuro of Cask ; bars =haty, or (3) a loes,9f sub- -
I cnocairty control, Any of these oc-l' Response
- acurrences radiologicalcould potentially create d harard. A cask and the nuclear fuel it con-
. Z.-_o _m
- , _ j tains can undergo various types of l damage when subjected to mech- 1 anical loads. The most significant ,
damaae would include material yielding, dimensional changes, and 13
CASK CHARACTERISTICS AND RESPONSES Thermal Loads-Measure Measures of Cask and of Cask Response Spent Fuel Response Heat from a fire can conceivably to Mechanical Loads damage cask components, the , ,. , -
----4 cask structure i,tself, or the spent om a-we y, fuel. The more important types of Tr * *' =ta =
A cm w damage can involve degradation of . f7,.'c*.* o a cask seals, melting of the lead '*** g ____. y gamma shield, or structural failures, s,vs.ne w u.r, u rs moo The significance of high tempera. tures on spent fuel is that it can
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- si W,wi rupture and release radioactive material into the cask.
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e ss un e The temperature at the centerline of the cask's gamma radiation
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shield is the indicator most likely % 0.2 ----+ 02 S to reveal the extent of cask di Ne "[ Maw - damage from fires associated with { . %'7'p', "' ..0""")'- ^7d" transportation accidents. Four ! . gY *'og'no g 4*'at-> temperature fevels are defined to 3 o o j categorize five ranges of cask and CASK DAMAGE FUEL DAMAGE ' ! fuel damage. These response DESCRiPTOR DESCRIPTOR ranges are indicated in the next l column at the bottom of the page. Measures of Cask and I 1 Spent Fuel Response l What Does terein ~ to Thermal Loads
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< TEMPERATURE PF) AT CtNTERLINI 0F CASK GAMVA SHl(LD am a,wa- wu ' ,
14
CASK CHARACTERISTICS t
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4 . Thermal Respor.se, 'F 4 '&b " h Ziie.CC f (Centerline Lead Temperaturel ,i i l Evaluating Cask and m ., J Spent Fuel Response ! SUPERFICIAL DAMAGE-No perme. MAJOR DAMAGE-Lerge contelnment I to Accident Loads nont deformation to contelnment vessel deformations without g see frec. I vessel. Temperatures too low to tures or ruptures. Temperatures high degrade material. Strains and enough to melt lead shielding. [ Or' the previous two pages, cask temperetures lose than or equei to I con'ainment strains and Centerline values considered acceptable following I shickt temp *tatures were defined imPo*itlo" of ~'egulation-defined ~ j separately to characterize broad hYP*'h'*I ***3d*"' **"di" l 1 categoi l es of cask and fuel . l j d: mage, in real transportation ac- f,[ i i cidents, Lowever, a cask could undergo a combination of mech- MINOR DAMAGE-Umited permanent DAMAGE EXCLEDING DEFINASLE -{ , containment vessel deformatione. RANGES-Fractures or ruptures posel+ i j anical and thermal loads. The Temperaturee approaching the tense bie. Temperaturee eufficiently high to cask resporne matrix shown on where the lead shield could melt end effect cask and spent fuelintegrity, t this page therefore combines the the seale could degrade. i i I - 1 15 > l i i_ _ __._ _ . . - - _ -
l l CASK CHARACTERISTICS l AND RESPONSES ! l l l l l structural and thermal responses to This relationship is described on presumed to cause containment ! categorize cask damage from all pages 16 through 19. Second, the functional failure, but without possible combinations of mechani- likelihood that the specihc acci- gross rupture of the containment cal and thermal loads, dent scenario (for example, impact (see figure on opposite page). The into soft rock slope) can lead to a lack of any gross rupture is a ! The process of categorizing cask cask response within a particular reasonable expectation based on response for a specific accident region must be evaulated. This the known ductility (that is, the se snario is best described by an part of the evaluative process is ability to stretch without fractur-example. From the figure on further described on pages 20 ing) of the stainless steel material page 7, scenario 20 indicates that through 27. typically used in cask containment about 2 of every 1000 truck acci- shells. At these strain levels, , dents are expected to result in an however, the impact loads could impact into a slope consisting of Relationship Between cause the lead gamma shield hard soil or sof t rock. Cask material to "slump." Where voids damage from this type of accident Cask Response and or gaps in the shield occur, can be estimated (in terms of Potential Radiolo0 ical radioactivity inside the cask could maximum containment vessel Hazards increase radiation leveis outside strain) if truck velocity, ang!e of the cask (see figure on page 19), impact, and cask orientation at im-pact are specified. Similarly, if a For most cask responses to The major difference between ac- i fire occurs during this accident (an transportation accident loads, any cidents causing 0.2- to 2 percent event expected in about 1 of every resulting radiological hazards can strain as opposed to 2 to 100 slope impact accidents), be conservatively estimated with a 30-percent strain involves the damage to the cask can be high degree of confidence. behavior of the fuel rod cladding estimeri in terms of temperature that contains the spent fuel within at the centerline of the lead shield Relationships of the cask. The lower range was if the fire temperature, duration, Mechanical Loads, Cask assumed to cause failure of up to I and cask location relative to the Response,and 10 percent of the fuel rod clad-fire are specified. The overall cask ding, whereas at the higher range, damage for the entire spectrum of Radiological Hazards all rod claddings are assumed to transportation accidents charac- fail, in either case, experimental I terized by cask impact with a soft For accidents causing small struc- information on radioactive releases ! rock slope can be calculated and tural strains in the cask contain' from failed fuel rods is used to placed into one of the response ment shell, no radiological hazards establish the fraction of gaseous, regions shown on page 15. would be expected since, for less volatile, and solid radioactive than 0.2 percent strain, no signifi- material that could escape from Two further steps are then re, cant permanent deformation each fuel rod. For the purpose of quired to complete the evaluation would occur in the containment this study, all of this material was of the level of safety provided for shell* assumed to be released from the spent fuel shipments. First, each cask, although in reality, a large response region must be con- Strains in the 0.2 to 2 percent or but undefinable fraction would sidered in terms of the radiological the 2- to 30 percent ranges were "plate out" or adhere to surfaces hazard that could result from the within the cask, specified level of cask damage. l
)
i 16
CASK CHARACTERISTICS AND RESPONSES P t Presumed if either: l.[{[$71396k l.. E8 Typical Radioactive Material Release (1) Cask containment vessel strain
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- 17 i .
CASK CHARACTERISTICS AND RESPONSES The radiological hazards from spent fuel within the cask, how- Between 6500F and 10500F, re-accidents causing cask strains ever, would not reach tempera- lease of radioactive material from greater than 30 percent could not tures high enough to fail the fuel the cask or increased radiation be precisely predicted because of rod cladding material. As a result, levels outside the cask from con-the extensive and potentially any potential radiological hazard tained material are more likely to varied nature of cask and spent created by a release of radioactive occur and the magnitude of the fuel damage. In these situations, material from a cask would be resulting hazard could become all gaseous material was presumed limited to gaseous and volatile larger. The major factor affecting to be released while radioactive materials that have escaped from the potential radiological hazard is ' material in volatile and solid form fuel rods whose cladding has the fraction of fuel rods experien-was arbitrarily assumed to increase failed during or before the acci- cing cladding failures. For shield by a factor of 10 over the values dent for reasons other than the temperatures in this range, fuel predicted for accidents causing fire. Based on past experience, rod temperatures can cause clad-strain in the range of 2 to 30 per- 3 percent of the fuel rods in a ding failures; therefore, any radio-cent. Only a very small fraction of shipment were assumed to have active material in mobile form truck or rail accidents, beyond any cracks or breaks as a result of could be released from the fuel to known accidents, could be severe their use in the reactor, handling the cask. If cask containment is enough to cause strains greater and storage before shipment, or compromised, this material could than 30 percent in the cask con- vibrational loads during normal reach the environment. Experimen-tainment shell. shipment. talinformation on the release of radioactivity from spent fuel has At centerline shield temperatures been used to estimate the magni- - Relationships of Thermal between 6000F and 650'F, two tude of the potential radiological Loads, Cask Responso, types of radiological hazard could hazard. The conservative assump-and Radiological Hazards be creatt'd if lead is used as the tion was made that any material , gamma shield material (as is the released inside the cask would l case for the representative cask escape from the cask to the Fires resulting from tror,sportat. ion designs). Lead melts at 621of and environment. accidents can affect a spent fuel expands in volume during the cask and its contents. If the fire melting process. This expansion if centerline shield temperatures does not cause 500*F temper- can cause structural stresses that exceed 10500F, a cask's functional l atures at the cask shield cen- can result in loss of the cask's capabilities could be affected by terline, no radiological hazard containment function. When the several complex chemical, thermal, would be expected since cask lead cools and resolidifies, its con- and structural processes that can-structural components are not traction can cause voids or gaps not be precisely predicted, in susceptible to thermal deteriora-to form in the gamma shield. these situations, all gaseous radio-tion or damage at temperatures These gaps degrade cask shielding active material was presumod below this level- capabilities and so increase radia- released to the environment tion levels outside the cask, as whereas the release of radioactive if temperatures at the shield shown in the figure on the op- material in volatile or solid form centerline should reach between posite page. In this study, a cask's was arbitrarily assumed to increase 5000F and 6000F, certain cask seal loss of shielding capability was by a factor of 10 over values materials could degrade and lose calculated as a function of j their capacity to function. The temperature. A cask configuration l that maximites lead slump and subrequent voids, thereby max-l imizing radiation levels outside the j casks, was also assumed. l l l 18
CASK CHARACTERISTICS AND RESPONSES i I l I Typical Radiation Presumed if e!!her:
- Level Increase as a (1) cask containment sassel strain
! Result of Lead exceeds 0.2 percent, or (2) centertine gamru shield (leadi Slumping temperature exceeds 600*F Fuel Bundle + , . I ,,' o ' Void 3
,.',..*o***
( p ..*; o',' dr"eas of ! o' (< ', *,.* *o, . .
, ,' . increased Radiation.
. Level o,*
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. . o* :o,. *
- 7[ en erline Allowable Under
' i Accident Conditions gLead Gamma r Shield increasing
\ Radiation (Cask Containment Shell N Levels As Void
' ' (Lead Slump)
\ Increases 3
p k : i ! 81 P
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s
\
e i _ Distatico From Cask (log) \ i 19
CASK CHARACTERISTICS AND RESPONSES assigrsd for temperatures in the massiveness of the object struck, abutments were assumed to occur 6500 to 10500F range. As is the and the orientation of the vehicle at an angle less than 20' from cars for accidents causing ex- or object at the time of impact head on. About 21 percent were tr,mely large structural strains, no (front, rear, or side impact). estimated to occur within 10' of
- ,istorical truck or rail accident head on, could be specifically identified that would have the potential to cause G Velocity at impact shield temperatures above 1000 F. 9 Hardness of Object Struck Potential cask velocities on impact were principally based on records The hardness and massiveness of of truck and rail accidents. The the object struck was determined, Cask Damage-What truck informat;on shown on for the most part, by the informa-Accident Conditions page s was derived from a sample tion from the accident scena.rios Are important and of truck accidents causing fatal- described on pages 7and 9. Sur-ities or injuries reported by the faces, such as hard rock, r, oft How Are They California Highway Patrol. The rail rock, and clay / silt, were modeled Defined? int rmation was derived from to provide a conservativo represen-mainline accident data available tation of the variety of possible from the Federal Railroad Ad- surfaces occurring within these Damage Caused by ministration. For accidents involv- three "earth" classifications.
Mechanical Loads ing falls, the velocity of impact was based principally on a survey The most important accident con- of bridge heights aloro a typical 9 Orientation at impact section of interstate m. c.ay. The ditions used to define the veloc ty of trains invoi., in truck mechanical loads imposed on a Cask orientation on impact was mpacts was denved from rail- estimated for each accident cask during an accident are those associated with various impacts. highway grade crossing accident scenario similar to the process information, used to determine the possible Because of the large weight, hard-ness, and rigidity of spent fuel angles of impact. For impacts wlth casks, loads caused by crushing, slopes or in impacts with other 9 Angle of impact vehicles, any orientation was con-by projectiles, or by other mecha-nisms have been demonstrated to sidered equally likely. For impacts The angle of impact between a with bridge columns and abut-be far less damaging than loads cask carrying truck or rail car and caused by impacts with hard, ments, all orientations were con-the object or surface hit was sidered possible, but the most massive objects. As in any impact estimated for each of the accident involving a motor vehicle or train, hkely orientation was estimated to scenarios shown or' pages 7 and 9. involve an impact with the front tho damage sustained would de- For example, head on impacts pend on vehicle speed, the angle end of the cask. with objects such as bridge of impact (a head on or a side- abutments and columns were swiping impact), the hardness and estimated to be far more likely than a side swiping impact. Specifically, about 40 percent of all impacts with columns or 20 \
CASK CHARACTERISTICS AND RESPONSES Damage Caused by example, the thermal loading to a was the location of a cask relative Thermal Loads cask involved in a collision with a to a fire resultir,a from a transpor- ! tanker carrying flammable cargo tation accident. In the absence of can be estimated by knowing the recorded data, the researchers l The temperature of an accident. maximum volume carried by a provided estimates that would be g:nerated fire is the most impor- typical tank truck and the nature prudently conservative. The result i t:nt consideration in assessing of the product being shipped (for was a presumption that in all ac-potential cask functional degrada- example, gasoline). For accidents cidents involving fires, a truck tion, The cumulative heat affecting involving trucks or trains carrying cask would be located at or within a cask depends not only on the nonflammable cargo, knowledge 31,5 feet of the fire center, the temperature and duration of the of fuel tank volumes and the types chance of any specific location fira but also on the extent to and amounts of combustible within this range being equally which the cask is exposed. Data material typical of truck or rail car likely. For rail casks, this location on fire temperatures and durations construction is sufficient to allow parameter was broadened slightly are not readily available in similar conservative estimates to to encompass a range of 0 to 43 accident records; however, con- be made, feet. Beyond these ranges, the servative estimates of fire tem- therma! loads were not significant. peratures and duration can be The only accident condition that , calculated based on pertinent in- could not be based, even quali- ; formation about the accident. For tatively, on recorded accident data l 4 ,1 4 i a , p d ! 1 j l 21 l
POTENTIAL HAZARDS AND RISK targets are shown to cause no scenarios marked with asterisks on functionai damage to a cask (see pages 7 and 9), the possibility of opposite page). (These scenarios cask functional damage is con-are shown without an asterisk on trolled by accident specific pages 7 and 9.) To illustrate this parameters. For example, a truck process, consider damage to a carrying a spent fuel cask could Fraction of Accidents truck causod by a variety of colli- hit a bridge column at 00 miles sions with animals and pedestri. per hour. If the truck and cask Without Any Expected ans: motorcycles; automobiles; side-swipe the column, however, Radiological Hazards other trucks; and, finally, fixed ob- the effective impact velocity (cask-jects. Collisions with animals, vehicle velocity perpendicular to pedestrians, motorcycles, and, to the column) could be only a few For every 1000 truck or rail ac- some degree, with automobiles miles per hour and the resulting cidents invoMng spent fuel typically cause little truck damage. forces would be insufficient to shipments that are capable of These objects are "sof t" relative damage the cask functionally. A causing injury, death, or signifi- to the truck, and as a result incur second possibility is that the truck cant property damage,994 would most of the damage sustained in hits the bridge column or abut-be expected to causo no signifi- the accident. Shipping casks are ment head on but the truck and cant radiological hazard. This massive, heavy structures so that cask are traveling at less than estimate took into consideration the objects so indicated on pages 30 mph. Because current regula-cask responses to both mechanical 7 and 9 are indeed "soft" relative tions require that a cask be sub-and thermal accident loadings. to the cask. jected to a 30-mph impact on an unyielding surface without sustain-Mechanical Forces ing unacceptable damage, any im-Summing the accident rates for pact of less than 30 mph on a O Responses to "Non-Severe" ' " " los invoMng generally fht surface would not be N' "ts wnh a ,pnaj, imp soft object pro- expected to cause functional Transportation Accidents vides a basis for concluding that damage. When these comhmi-How the cask responded to these accidents describe abat 950 tions of possible accident t of mry 1000 truck accidets, parsmeters are taken into account, mechanical forces was first con- Su h accidets wmld be unkkely sidered for the objects identified in at least 44 out of every 50 ac-to cause any functional cask cidents involving impacts whh the accident scenarios described on pages 7 and 9. Estimates were ** 9 ' ' "non soft" objects or surfaces s mari s,I sH.railr adimpacts ft object accidet mado of the maximum forces that would be expected to cause nc could be generated by each object " # ##
- ta accidents
- or surface when struck at any im. same outcome is anticipated for pact velocity. These estimates railroad accidents: conversely were compared to the force O Responses to "Hard" object stated, a maximum of about 6 ac-necessary to cause a cask's con- Impact Accidents cidents out of every 1000 have the tainment structure to begin to pet. potential to cause some degree of manently yield or deform. Through in accidents involving cask im. cask functional damage.
this comparison, many scenarios par *s with potentially massive involving impacts with "sof t" and/or hard objects (see the 1 22
POTENTIAL HAZARDS AND RISK i n g-gy r . e*-~~ i Accident Scenarios (n 1 : G:nerating Mechanical 1' - ' Forces incapable of
/- )
C using Functional C:sk Damage t~~ : E; m ,I
/
//
. ,/, Y&d '
/j.?-
y lh .. M _l g. C,[s MsCzc> - @ &O@ g wg^ N:g. y s
.%' ~
N950 of Every 1000 Accidents e y-o "Soft" Target Vis-a-Vis Spent Fuel Cask @~ ' ' @~ g,,m _ _ __ Cask Velocity ARq&;
% W / .<rlN. ,,m
,/g '
N44 of Remaining 50 4 u s y ty;
~;3 yj ..'..
Accidents \;\ ' . a = . ?, * ' , - , One or More of the N' ...--%
,. g .
Following Apply: \ - . .~ s_ p/ j]
) { ,
l ,j .. '.0bject . o Velocity Too Low olmpact Angle TooShallow
/ -~-
/7 , ', . Surface t
., 2...
L t~ .w' , ! s %, impact Velocity
Conclusion:
994 of Every 1000 Truck i Accidents Generato a = lmpact Anglo l Mechanical Forces Incapable o,f Causing Cask FunctionalDamago. # = Cask Orientation Angle 23
_= -. - . - . i j POTENTIAL HAZARDS AND RISK i Thermal Forces likeiv to completely engulf a cask would be limited by the amount of over 16 feet long and 5 feet in fuel in the fuel tanks of the vehi-I diameter. The potential for func. cle involved in the accident. Cask damage from fires could tional cask damage from fires is cause melting of the lead shield or therefore limited to accidents in. These estimates were chosen con-i degradation of the closure seal. volving tanker trucks, locomotives, servatively because of the lack of , i Either form of damage requires and tank cars with large quantities actual accident data. The likeli-that the affected component reach of flammable materials. hood distribution applicable to fire temperatures in excess of 500*F. temperatures is shown in the bot-The mass and heat capacity of tom figure on page 8. A large spent fuel casks are large. For a The approach taken 3 calculate fraction of fires were assigned 4 truck cask to reach such a tem. cask responses to fires was to temperatures in excess of those t 1 perature, it would have to be determine the likelihood that a fire typicalin such accidents. '
; engulfed in a 1700'F fire for over would occur given a specific truck on hour. For the larger represen. or train accident scenario defined The fire temperatures and duration tative rail cask to so;tain equiv. on pages 7 and 9. Each scenario parameters, when cons!dered with a'ent damage, it would have to be was ass;gned one of eight fire the potential for cask involvement '
engulfed for an estl mated duration estimates (five for truck in any accident caused fire, 1.35 hours. With few exceptions, and three for rail accidents), two resulted in the prediction that less I only about 1% of the accidents in of which are shown on the upper than 1 of every 1000 truck or rail ! the truck and rail accident figure on page 8. For rail acci- accidents has the potential to I sconarios listed on pages 7 and 9 dents, a significant fraction of cause a fire capable of com-involve fires. Many of these fires fires were assumed to have long promising cask safety. This con-would be fed by diesel or gasoline durations (1 of 8 for the accident clusion is illustrated on the op-fuel from the truck or other vehl. scenarios illustrated on page 9 posite page. ! cle involved in a highway acci. were assumed to last longer than dent, or from diesel fuel, 1 hour). For truck accidents with i i lubricants, and rail car structural other trucks or with trains, a materials in railroad accident similar fraction of fires exceeded 1 scenarios. These types of fires 1 hour. Only for truck accidents I would not be expected to invoMng no collision, a collision gene ate the heat necessary to with a fised object or a collision i causo functional cask damage, with an automobile were the fire
, Furthermore, these types of fires durations limited so tlut only are generally localized and not about 1 percent or less exceeded I 1 hour. This assessment reflects
); the likelihood that fire durations
\ \
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i i - 1 i 24
POTENTIAL HAZARDS AND RISK j Distance Between [ Cask and Fire l
\
y ) a...
, is'""
- ,.. 1
)
Fire Temperature
\and Duration a . ,, % j *(;lm. zw. ..
aw unw;;wawww awv.ww wmnvu,mm wmxvyw
~ \ ,, ] """'
Accident Scenarios j'} \ I ' Generating Thermal / ,,g _- _ Forces Incapable of ( ,.- Causing Functional Cask Damage k *O ~ *#~h * .. Fire Not Hat Enough or rv in Greater Than of Long Enough Dura: ion ::: 999 of Every 1000 Accidents to Affect Cask - No Cask Function Damage I pg;gg4gygpgggp from Thermal Forces
^
~ l
\ \\ &&> C- ,a
( .. l -
~- l 1
d,J ... Y
~ ~
Cask Location Not Close Enough to Fire i VDf%@Vjffadshi@ WHA \Q%N& %i(#W//faWFvhWI
\
25
=_- . _ _ __
POTENTIAL HAZARDS AND RISK t t Potential Radiological result in a cask response within gross rupture of the cask's con-this region. Simaady,4 of the 6 tainment shell would not be ex- ! Hazards Resultin9 , damage-producing rail accidents pected. The Seat could melt lead From Functional Cask are estimated to generate similar in the shield, resulting in voids j Damage tevels of damage, in this gray and increased external radiation ,
, area, containment vessel structural levels. For cask responses in the ,
] damage is limited (to strains of large open area, radioactive material ; The evaluations described on less than 2 percent) and cask releases and/or external radiation pages 22 through 25 indicate that gamma radiation shield tempera- levels potentialty could slightly ex- j less than 6 of every 1000 truck ac- tures within the body of the cask ceed existing regulatory com. I cidents and 6 of every 1000 rail are typically below melting pliance values. Just about 2 of i accidents could cause some func. temperatures (less than 600*F every 1000 tru:k and rait accidents
- tional cask damage. Damage to compared with the lead melt involving a spent fuel shipment are
, the cask could lead in turn to temperature of 621'F). Note that conservatively predicted to be ! d radiological hazards caused by other casks which do not use lead capable of causing this level of l cither (1) the release of radioactive as a shield material would be ex- radiological hazard. j material from the cask's contain. pected to experience little, if any, i ment, or (21 an increased level of shield damage. At this level of Finally, only about 1 in every l radiation emanating from the response, any radioactive materials 100,000 truck accidents and 1 in ' spent fuel within the cask caused released from the cask would exist every 10,000 rail accidents are by a degradation in a cask's as a gas and only a sma!! fraction calculated to lead to cask damage r shielding. The magnitude of any would occur either in volatile form as described in the outer ring of l radiological hatard will vary or as small solid particles in an response regions. No documented l depending on the extent of the aerosol. Furthermore, little accident can be specifically iden- , cask's damage-the hazard tend- degradation of the cask's shielding tified that can cause this degree of t ing to increase in magnitude as would be expected since the cask damage. As indicated on , 4 cask damage increases. In order to mechanical and thermal forces im- pages 16 through 20, the evaluate this variabihty in the posed on tho cask are insufficient radiological consequences of potential hazard, three broad areas to cause significant shield "slump" events in the outer ring were l of cask response were charac- or voiding, in quantifying the hypothesired because of the ex- i terized (see the figure on the op- potential magnitude of any radio- tensive and potentially varied l posite page). logical release created by nature of cask and spent fuel ] j responses in this area, researchers damage. Similarly, the potential i Most of the accidents capable of estimated that the magnitude of for a loss of the cask's subcriti- l 4 causing any functional cask any release was likely to be less cality function would be expected damage produce the hmited than compliance values applied to to be restricted to a small fraction responses shown within the gray cads after they have been sub- of the "outer ring type events" in I area of the figure. In fact, of the 6 jected to the hypothetical accident which sufficient quantities of truck accidents out of every 1000 conditions described on page 5, water were physically present. l 1 capable of causing any functional j damage, about 4 are estimated to in the large open area, structural i damage to a cask's containment
! could be significant, although l
i d 1 1 1 26
POTENTIAL HAZARDS AND RISK i l TRUCK
- V, f f Al fS 3 e
. - - .. - -/ - - - -
N2 per Thousand : Less Th " 1 P* M'" " [ {A B )
. ( Al Bo ne 5 %g;G ~2 ~2 g E N 994 per '
M per 100 per 100 if[t@i fTm6p[4 ) Thousand Thousand Thousand Fraction of Truck 1, w T, T, ffshf 13 and Rail Accidents e e a 00m involving Spent Fuel THERMAL RFSPONSE, 'F Shipments that Cause """*"" n,,t 9 M S3 J 4
) j N N6 2 per 10 -
Less Than 3 per 10 Ymon M-?pI f Thousand (An Bones) I *' g 2 e = _ a
$g ., W f f ,
f Al home
~
N ' >>
. e;rs i
% 564 per Thousand W
~%1Op % 1 per Thousand
% 1 per Thousand 4,g'M1 fhe
$y tQR g [ J ,
l 1, T: T3 T4 L (E001 M (6CO) (10 W
; THERM AL RESPONSE, 'F (Centeri'ne Lead Temperature)
%:i, %,-we re , t*, rw~w en l 27
POTENTIAL HAZARDS AND RISK
=
Interpretation of the to remember that the statements n event likelihoods apply to the Engineering models were then used to predict how a spent fuel Relationship Between performance of the defined shipment would respond in these Potential Radiological representative cask designs-real accidents and what macnitude of Hazards and Real-World cask designs are expected to pro- radiologica: hazard might be Severe Accidents vide a greater level of safety in created. A risk measure was deter-trar ,portation accidents. mined by multiplying the magni-tude of each potential hazard by Predicting the likelihood and The second interpretation involves its occurrence frequency and sum-nagnitude of any radiological the prediction of the performance ming all the resulting values, hazard in a severe transportation of the representative cask designs accident is not an exact science. if they had been involved in cer. This type of risk measure has a The forces applied to the spent tain historically documented, regulatory precedent applicable to fuel shipment in extremely severe severe transportation accidents, this study. In December 1977, a accidents are based on extrapola. Four specific events were selected study that evaluated the risk for all tions of historical accident data, from about 400 severe accidents radioactive material shi~nents, in-the evidence from physical tests, that, in turn, were selected from a cluding spent fuel, was published and predictions from engineering much broader DOT data base. The as a Final Environmental State-models using conservative as- description of the four events and ment (FES).* The eva'uations con-sumptions. What is clear is that as the predictions of cask response tained in the FES indicated a the severity of accidents increases, are illustrated on a portion of the radiological risk from transporta-the extent of possible damage to figure on the opposite page. tion accidents of one latent cancer casks and spent fuel also fatality every 59 years for all pro-increases. Together, these results are be. jected 1985 radioactive material lieved to present a fair picture of shipments. Most of this risk was This summary report has described the minimum level of safety pro- associated with shipments of the processes and results used to vided during shipments of sport medical radioisotopes. The con-assess the level of safety for spent fuel. The reader is encouraged to tribution from spent fuel fuel shipments. To better under- refer to the LLNL report for a shipments was 2.5 percent of this stand the results, two further in, complete interpretation of the estimate, terpretations of the level of safety studies approach and results. can be made. First, an illustration of the relationship between poten. Risk Estimate for tial radiological harards and som* Spent Fuel Shipments understandable accident param-eters is provided in the illustration on the opposite page. The "Risk" and "expected value" are illustration applies to truck Ship- two of several measures used to ments of spent fuel subjected to predict future occurrences based mechanical forces. The expected on past experience in fields rang. yearly accident event frequencies, ing from safety to sports. In this indicated on the figure, include study, historical information on consideration of predicted spent truck and rail accidents was sup- . .w,.,nm g %g y,g fuel shipment activity and a truck piemented by route survey data to by As and ow Modes " NuyG 0170, accident rate of 6.4 accidents per predict the occurrence frequency 0* ente 19R milhon truck miles, it is important of severe transportation accidents. 28
Accident Scenarios Generating Mechanical Forces Potentially Capable of Causing a Radiological Hazard Occurrence Rate POTENTIAL MAGNITUDE OF !
= 6 Events per 1000 Accidents R ADIOLOGICAl, H AZARD l I
= One Accident Expected Every r 10 Years (Assuming N3 Mdlion
- Material Releases (PrimariFr Gases Shipment Miles Per Year) ,
and Vobtses) Less Than Cask Veloci - Compliance Values
- Object B
- No Significant increase in 4 Even er 1000 Accidents or Extemal Radiation Levels 1 Ex Event Every 14 Years $
l
'
- Material Releases (Primarily Gases l X -- and Volatiles) Could Exceed l
Comphanco Values' by a Small Factor (i.e.,2 or 3 Times) a , 4 - 4 ( f Cask Velocity Normal to Surface or a External Radiation Levels Could Equal or Slightly Exceed (by a ! r Object Between 50 mph and 75 mph Factor of N 3) Comphance Values * ( l l "Non Soft" Object l Less 1 Event per 10 MAon Accidt of No Espected Events '
- Material Re' eases Estimated to i
i During story Shiprtwots Enceed Compliance Values' by About a Factor of 20 Dependent on
'- e the Specifics of the Acck3ent Cask Vek>c Object Eict -
- Extemal Radiation Levels Estinuted to Exceed Comphance Va!ves' by a Factor of M Dependent on the
( Speofics of the Accident
' Compliance Values as Defined in Current Regulations 0% -s
l T1 POTENTIAL HAZARDS APEltTUllE AND RISK CARD Alto Available on Aperture Card Predicted Cask Response tO Selected Historical Accident Events CALDECOTT TUNNEL FIRE 4/82 Predicted Cask Response I 80 BRIDGE ACCIDENT 3/81 e 3 Vehicle Conisjon - Gasoline
- No Significant Impact Damage .
- Collision With Pickup Truck Truck Trailer, Bus and "Soft" Objects and Fall from St Foot High Autotnobile
- 45 Minutes ' 1900'F Causes 507F Cridge Onto Soil
- 8.800 GaMons of Gasoline Ce. ter4ne Temperature Predicted Cask Response
- Fire of 2 Hours and 42 Minutes -
40 M:nutes'1907 F * #4 "Ph,*P#'
- No Sip ficant tro,nact Damage h
LIVINGsTON TRAIN FIRE 9/82 3
- Duailment of Vind Chloride /
65 30 y .-r c g g = r y[7 Petroleum Tank Carc
.x
'l
*f # jJ/ .
' [N
- Large Fires for Several Days Moved Over Large Area
,f fg .
- 2 Explosions E
a # 4J Predicted Cask Response j Ulf f 9f.['
/ :
- Maximum Probable Cask Exposure to Petroleum Fire Between 82 Hours and 4 Days
* 'd cant Damage from HARD SURFACE h
. p' . j g,p,Si o,
E a s Pf s '[ s2 f
- Centeriine Shield Temperature Between 600cF and 727F Dependent on Degree of
.h a c .
ACE f 1111 M 1 ,1 ) 1
, Cask invotvement 0 500 600 650 1050 Center ine Lead Temperature (*F)
DERAILMENT ON ALADAMA RIVER DRIDGE 1/79
- Plunge Off 75 Foot High
, Bridge h j-
- Railcar impacts Ints Water and Mud No Rad ofogical Hazard Radiological Hata d Raiological Harard Appro ntmates Exceeds Compliance Predicted Cask Response Comphance Values' Va!ues By Up to a
- 47 mph Impact in Soft Target Factor of 4
- No Significant Impact Damage 72 M B3 09.19 -E'
- .. . s POTENTIAL HAZARDS AND RISK In the FES, the predicted per. The LLNL study included a more and the presumed release of solid formar'ce of radioactive material detailed approach to the calcula- material,' the risk, as calculated in packages was based, for the most tion of radiological harards that in- the t LNL study, is shown in the part, on engineering models and volved the consideration of re- following table to be less than consuvative engineering }udg- leases of radioactive material as one-th rd of the values estimated ments. The LLNL study, on the small inhalable particles. Any solid in the FES. Therefore, to the ex-other hand, focused entirely on material release from a cask would tent that the Commission's conclu-sperit fuel shipments and provided require the creation of a direct sion on the adequacy of NRC a d> stalled engineering analysis of release pathway from both the regulations were initially valid and package or cask performance containment provided by the fuel were dependent on the FES risk under severe transportation acci- rod and the cask (that is, a estimates, the LLNL study has not dent conditions. The table on this pathway much more direct than identified any increase in risk that ptsge compares the results from the one needed for gaseous or volatile would change the Commission's tivo studies, material releases). With the conclusion.
arsumption of such a pathway
' A sNppeng can has been Subfected to 81-W< . l . .o : , RISK RESULTS 4 COMPARISON ' -
ua bv . ee to **= cea .nd fM y; WITH PAST FES EVALUAT1,0N, yp C '# , C .' g ,*, O anteta% weapon. TNs device nowW carw I FES LLNL STUDY *" *PP'o'a**v lecN mt* * (NUREO 0170) RESULTS *'*v9""******* 'd **"t* '"*d 'W"' ESTIMATES 'w*d *"d * * ** *d k * ** '* * ** of 2/100.CKD of tv 1 .wed we.sht 610 greens of fuell m . Wewth form No i Fraction of Transportation l Accidents invoMng Spent Fuel Shipments Causing 0.09 (Truck) 0.006 (Truck) 7,' j ,"' j**"** ' *" * ** " " "y*d
,,,73 , ,,.
1 0.20 (Rail) 0.006 (Rail) %, ,,33 Any Radiological Hazard i Fraction of Transportation Accidents involving Spent 0.ON (Truck) 0.00001 (Truck) i Fuel Shipments Causin9 0.002 (Rail) Largest Estimated 0.00013 (Rail) Rad 4ological Hazard Overall Annual Risk 0,00M
'j From Transportation Less Than 1/3 Latent Cancer of FES Value Accidents invoMn9 Fatalities Per Year Spent Fuel Shipments 30
Notes i mew l l e I 1 ennup per - P i I l i i I I i
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i I .i i i t
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I i 1 If 4 1 1 1 1
.____. ____ __ m_ .,
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