ML19344B245
| ML19344B245 | |
| Person / Time | |
|---|---|
| Issue date: | 08/31/1980 |
| From: | Calkins G NRC OFFICE OF STANDARDS DEVELOPMENT |
| To: | |
| References | |
| NUREG-0590, NUREG-0590-DRFT, NUREG-0590-R02-DRFT, NUREG-590, NUREG-590-DRFT, NUREG-590-R2-DRFT, NUDOCS 8008260007 | |
| Download: ML19344B245 (15) | |
Text
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1 NUREG-0690 Rev.2 L Thoughts on Regulation Changes for Decommissioning i
4 Draft Report 4
e G. D. Calkits Office of Standards Development i
l i
U.S. Nuclear Regulatory Commission
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NUREG-0590 Rev.2 Thoughts on Regulation Changes for Decommissioning Draft Report Minuscript Completed: July 1980 D te Published: August 1980 i
G. D. Calkins Divialon of Engineering Standards Office of Standards Development U.S. Nuclear Regulatory Commission Wshington, D.C. 20666 pn =cauq 1
i l
NOTE: Any opinions or conclusions contained in this paper are those of the author and do not represent official NRC policy.
~
NUREG-0590, Revision 2 CONTENTS
<N PAGE
1.0 INTRODUCTION
1 2.0 ' SCOPE AND PURP0SE..................................................
1 3.0- TERMIN0 LOGY........................................................
2 3.1 Definition of Decommissioning.................................
2 3.2 Definitions of Decommissioning Alternatives...................
2 4.0 AMEN 0 MENT VS. NEW RULE.............................................
3 5.0 MAJOR ISSUES......................
3 5.1 Alternatives and Timing.......................................
4 5.2' Planning......................................................
5 5.3 Financial Assurance...........................................
6 5.4 Radioactive Residues..........................................
7
6.0 REFERENCES
8 i
iii
. - -. =
NUREG-0590, Revision 2 1.0 Introduction During the State Workshops on Decommissioning of 19781 and 19792 the key sources of information resulting from the implementation of NRC's reevaluation of decommissioning policy and regulations were reviewed and discussed.
These 3 of reevaluation, published origin-sources were those described in the NRC plan ally in March 1978 and revised in December 1978 to reflect comments to date including those from the 1978 State Workshops and again in July 1980 to update i
schedules and information.
In brief these sources of information have included the following:
1 1.
Technical information reports by our major contractor, Battelle PNL, l
on the technology safety and costs of decommissioning various nuclear 7
facilities.
These included the PWR4'5' BWR,6 fuel reprocessing plant 0
i mixed oxide fuel fabrication plant and low level waste burial ground 8
and uranium oxide fuel fabrication plant.to The uranium mill was covered by its draft Generic Environmental Impact Statement.11 A report has been completed in the facilitation of decommissioning light r
i water reactors.12 2.
Technical information by a second contractor, ORNL, on the technology ts of decommissioned facilities.
and costs of terminal radiation surveys 3.
-Preliminary NRC staff studies of key issues:
financial assurance 14 and radioactive residues.15 The staff report on financial assurance has been supplemented by a contractor report.Is t
4.
A summary from a preliminary draft generic environmental impact 17 i
statement on decommissioning prepared by the NRC staff with assist-1 ance from Battelle PNL.
The information base is partially, but not seriously, incomplete.
The major shortcomings are with some of the detailed technical reports which are not finished. These include the studies on a nuclear energy cUnter with multiple reactors, non-fuel cycle nuclear facilities, uranium hexafluoride conversion plants, and fuel storage facilities.
All of these studies except the fuel e
s storage and uranium hexafluoride conversion facilities have been initiated.
In all cases sufficient information was available to allow the required safety i
and cost evaluations to be made as a part of the environmental impact state-ment.17 The radiological problems in handling uranium in a fluoride conversion j
i plant and fuel storage facility are similar enough to those of handling uranium in a fuel fabrication plant to allow the needed estimates to be made.
2.0 Scope and Purpose The scope of this paper includes all nuclear facilities except uranium mills and their associated tailings piles, high level waste repositories and low level waste burial grounds.
Rulemaking is already underway for these.
Proposed regulations in the licensing of uranium mills have been announced.ts i
In the case of high level waste repositories and low level waste burial grounds l
proposed regulations are'in the process of being drafted as new Parts 60 and
~
61 to the Title 10 Code of Federal Regulations.
Decommissioning will be covered i
_ in each of these regulations.
k w-v v.,.--,...
NUREG-0590, Revision 2 The purpose of this paper is to summarize the preliminary thoughts of the decommissioning staff in the Office of Standards Development at NRC and to stimulate participation of others relative to decommissioning regulatory changes.
These preliminary thoughts have resulted from evaluations of the information base described above.
It is emphasized that these preliminary thoughts do not represent a broad consensus yet.
The purpose here is to solicit comments and suggestions from a wide audience.
Although this paper was prepared initially for the State Workshops on Decommissioning in September 1979, it is also being used to stimulate participation from the public, the NRC staff broadly and other government agencies as well as the States.
This paper is revised here to update the information in the Introduction on the information base, to add a new section on terminology, and to make important additions to the key issues. Section 5.3 on financial assurance and Section 5.4 on radioactive residues.
Anyone interested in commenting on this paper, on the information base used as background for this paper or on any matter concerning decommissioning of nuclear facilities is invited to send them to:
G. D. Calkins Decommissioning Program Manager Office of Standards Development 1
U.S. Nuclear Regulatory Commission Washington, D.C.
20555
)
All comments will be included in the record of consideration by the Commission in establishing criteria and new standards for decommissioning.
3.0 Terminology Some confusion and misunderstanding has resulted from the variation of terminology used in the decommissioning field.
For example, the words decom-mission, decontaminate and dismantle have been used interchangeably for the decommissioning alternative consisting of the immediate removal of all radio-active material to permit unrestricted release of the property.
The word dismantlement has been used to describe decontamination activities that involve no actual dismantlement.
Similarly, the words safe storage, protective storage, lay-away, mothball and temporary entombment have been used to name the alterna-tive of decommissioning consisting of placing and maintaining property safe y in storage as a precursor to final decommissioning.
In the interest of ending the confusion it appears desirable to strictly define decommissioning and the major alternatives for accomplishing it.
Furthermore the use of pseudoacronyms for the alternative avoids words which may have several meanings.
3.1 Definition of Decommissioning Decommission means to remove the property safely from service and dispose of the radioactive residue.
3.2 Definitions of Decommissioning Alternatives
~
DECON means to immediately remove all radioactive material to permit unrestricted release of the property.
2
NUREG-0590, Revision 2 SAFSTOR means to fix and maintain property so that risk to safety is acceptable for the period of storage followed by decontamination and/or decay to an unrestricted level.
ENTOMB means to encase and maintain property in a strong and structurally long-lived material (e.g., concrete) to assure retention until radioactivity decays to an unrestricted level.
4.0 Amendment vs New Rule Collectively these studies and evaluations (see Section 1.0) suggest to the author that all nuclear facilities will require consideration in rulemaking revisions on decommissioning.
Current regulations cover the requirements and criteria for decommissioning in only a limited fashion.
For many types of nuclear facilities the rules are mute.
The rulemaking for decommissioning could be accomplished as a separate part of NRC's regulations.
However, the proposed action would directly affect licensing activities under Parts 30, 40, 50 and 70 of Title 10 of the Code of Federal Regulations (10 CFR).
This implies that amendments to the separate parts rather than a separate new part would be less disruptive of existing procedures and processes.
It appears that the parts shown below will require amendment:
Parts of 10 CFR Requiring Amendment Part No.
Title 20 Standards for Protection Against Radiation 30 Rules of General Applicability to Domestic Licensing of Byproduct Material 40 Domestic Licensing of Source Materia!
50 Domestic Licensing of Production and Utilization Facilities 70 Domestic Licensing of Special Nuclear Material 51 Licensing and Regulatory Policy and Procedures for Environmental Protection 5.0 Major Issues Furthermore, the various studies and evaluations show that there are five major areas of decommissioning which should be addressed in the amendments:
1.
Alternatives 2.
Timing 3.
Planning 3
~
NUREG-0590, Revision 2 l
l 4.
Financial Assurance 5.
Residual Radioactivity The issues of alternatives and timing will be discussed together below since they are very closely related.
5.1 Alternatives and Timing Generally, the primary goal of decommissioning of nuclear facilities should l
be DECON, (immediate removal of the radioactivity and release of the property on an unrestricted basis) at the earliest practical date.
In some cases DECON may not be most effective because occupational exposures ulay be reduced by using SAFSTOR, (safe storage to allow some decay of the radioactivity followed by decontamination or by'using ENT0MB (entombment) to allow decay of the radio-l activity in about 100 years to unrestricted levels.
The technical studies of the decommissioning of the various nuclear facili-ties suggest toe the author three major classifications of alternatives and timing.
These are based on the half life of the most critical and/or abundant nuclides involved:
l 1.
Half life of about 5 years.
Cobalt-60 is an example of this case, L
and it is the critical / abundant nuclide for nuclear reactors.
The foilcwing decommissioning actions would be permitted:
a.
DECON if occtpational exposures are properly managed.
t b.
SAFSTOR with surveillance for up to about 30 years followed by delayed decontamination unless the radioactivity decays to an unrestricted level.
I
\\
l c.
ENTOMB with surveillance for about 100 years if the radioactivity l
will decay to unrestricted levels.
This is not the case for reactors which may contain excessive amounts of long lived nuclides such as niobium-94 and nickel-59.
l A preliminary and partial studyt7 of the decommissioning of a l
nuclear center having multiple reactors indicates that the above l
criteria are valid there as well as for a single reactor site.
l l
2.
Half life of about 30 years.
The fission products strontium-90 and l
cesium-137 are examples of this case and they are the critical /abun-l dant nuclides for a fuel reprocessing plant.
The following decom-L missioning actions would be permitted:
a.
DECON if occupational exposures are properly managed.
b.
.SAFSTOR with surveillance for about 100 years followed by delayed decontamination unless the radioactivity decays to an unrestricted level.
4 j
NUREG-0590, Revision 2 3.
Half life greater than about 30 years.
The following decommission-ing action would be permitted:
a.
DECON.
5.2 Planning Decommissioning plans will be required of the applicants / licensees for all nuclear facilities.
The extent of this planning will increase with the complexity of the facility.
Initial and final planning will be permitted.
In these caus initial plans will be required at tne time of license application and final plans at the time of written notification of NRC of the licensee's intention to discontinue the activities covered by the license.
5.2.1 Initial Plans Initial plans will include the following:
1.
Alternative Tentative selection and description of the alternative for decom-missioning will be made.
This must be in sufficient detail to identify the approximate cost of the decommissioning activity to be used in connection with the financial qualification requirements.
Such cost estimates may be based on acceptable information from the literature such as that from Battelle PNL.
2.
Facilitation Description of facility desigit and operational features intended to facilitate decommissioning.
Battelle PNL has completed a technical study on the facilitation of reactor decommissioning.12 3.
Records Description of plans for the licensee to collect and safeguard records and archive files to support decommissioning.
This will include com-plete as-built and as revised drawings and specifications, significant opera-tional occurrences, and site specific background data.
5.2.2 Final Plans The final decommissioning plans will be in much greater detail.
They will be submitted in sufficient time to permit review and approval by NRC prior to the initiation of any actual decommissioning activity.
The lead time for this review will vary with the complexity of the facility.
For example, it would be a year for a major power reactor.
Final plans will include the following:
1.
Alternative Final selection of the alternative of decommissioning will be made.
This should include a detailed description including the major procedures and techniques related to the safety of the operation.
Plans for processing and disposin0 of all wastes will be discussed.
5
NUREG-0590, Revision 2 2.
Schedule i
Detailed schedules for completion of all decommissioning activi-j ties will be submitted.
3.
Administrative Controls The plan should describe the organization and procedures for accomplishing the decommissioning.
It should delineate responsibilities and i
j the requirements for review, audit and reporting. The quality assurance pro-gram to be applied should be presented in detail.
4.
Specifications The licensee will be expected to develop, evalbate and propose controls and limits to assure occupational and public safety.
5.
Training Details will be needed on a program for training of employees and contractor personnel.
I 5.3 Financial Assurance l
Generally, the goals in the area of financing the decommissioning of I
miclear facilities should be to provide a very high degree of assurance that Me licensee will pay the costs and to allow a wide latitude of approaches to implement that assurance." The costs for decommissioning various nuclear facilities are not well established because there has been only limited actual experience.
In order to provide more reliable cost data NRC has had Battelle PNL make detailed estimates for most nuclear facilities.
These estimates or comparable ones are estisfactory guidelines for these purposes.
Of course, the information on costs is expected to improve with time, and it is planned to require periodic reviews of the cost estimates to correct them as appropriate.
Three basic approaches, used singly or in combination, to implement the assurance appear satisfactory:
1.
Prepayment.
Cash or other liquid assests that will retain their value for the projected operating life of the facility may be deposited into a segre-gated account prior to facility startup.
Prepayment will probably be the only satisfactory alternative to cover costs involving long term surveillance.
2.
Sureties.
bonds, letters of credit and lines of credit that guaran-tee that the costs will be paid may be used.
It appears questionable that bonds of the size and for the time involved with power reactors will be available.
However, they appear to be availab'a for facilities that involve smaller costs and periods.
3.
Sinking Funds and Insurance.
The sinking fund or funded reserve i
l requires a prescribed amount of funds, subject to annual revision, be set aside annually such that the fund plus accumulated interest would be sufficient to pay for the t.osts at the time of decommissioning.
The weakness of the sinking fund approach is that ir the event of premature shutdown the decommissioning 6
NUREG-0590, Revision 2 fund would be insufficient.
Therefore, the sinking fund would have to be sup-plemented by insurance which would pay the difference.
There is some indit.a-tion that such insurance could be made available."
q Some reviewers, mainly those associated with nuclear power plants, of the above approaches to financial assurance have voiced concern that the options of an unsegregated sinking fund, negative salvage, or payment at the time of decommissioning are not included.
Their major argument is that options selected are more expensive. While this is true, none of the options signifi-cantly increase the cost to consumers.
The total cost of decommissioning increases the cost of nuclear power to consumers by approximately 2 to 5 per-cent.18 While a segregated sinking fund may be twice as expensive as payment 18 at the time of decommissioning it is not significantly more costly to consumers.
5.4 Radioactive Residues Discussions with the staff at EPA relative to acceptable radioactive resi-due limits indicate that:
1.
potential doses from decommissioned facilities should be less than those from cperating ones, 2.
doses (whole body equivalent) above about 5 mrem per year are probably unacceptable, 3.
justification would be required for doses more than one mrem per year, and 4.
a plan for complying with these criteria could utilize realistic rather than conservative pathway analysis.
Realistic analyses involve recognition that occupancy is less than 100 percent of the time, that the source of sustenance is not limited only to the decommissioned site, that self shielding reduces the dose and that resuspension is decreased by weathering as a function of time.
As considerations of the application of the above criteria to various nuclear facilities ha:: progressed, it has become clear that a dose range is more practical than a specific dose.
For some nuclide mixes and facilities it may be impractical and unnecessary to meet the 5 mrem per year criteria.
It appears that a goal for the release of decommissioned property on an unrestricted basis should be for potential exposure to an individual as low as reasonably achievable in the range of 1 to 10 mrem per year.
Technical and/or economic justificationmayberequired.
The application of the above criteria requires the ability to convert the doses in mrem per year to contamination levels in terms of surface or volumetric concentration of radioactivity.
A methodology for doing this was recently com-pleted.18 Reviewers of this proposed goal have expressed concern that radiation cannot be detected or that it would be prohibitively expensive to make measurements at that level.
These concerns do not seem to be well founded as shown below:
7
NUREG-0590, Revision 2 Recent preliminary work 13 has been completed at ORNL on the terminal radia-tion survey for the case of the decommissioning an 1175 MWe PWR.
This study shows that the technology is readily available to make a statistically-designed, terminal radiation survey with a reasonable degree of confidence and at a moder-ate cost, less than $250,000 at the 5 mrem per year level.
This cost represents only a fraction of a percent of the total cost of decommissioning a large reactor.
Furthermore, it indicates that the cost at a release level of a dose of 25 mrem per year is only about 10 percent less than the 5 mrem per year case.
It was found that the cost at a release level of a dose of 1 mrem per year would be extremely high and not easily estimated.
In addition; a historical review shows that in the 1960's that written criteria for acceptable level of radioactive residues for the release of decom-missioned property did exist and were utilized.19,20 The criteria were based on a goal of a limiting exposure to a few percent of the radiation protection standard of 500 mrem per year in an uncontrolled area.
Such radiation rates are similar to those expressed as a dose of 1-10 mrem per year.
Unfortunately, it was decided in 1973 to drop the written criteria and go on a case-by-case basis for the release of property.21 This lack of written criteria resulted in confusion and inconsistency which still continues.
22 In 1974 guidance for termination of reactor licenses was issued (Regula-tory Guide 1.86), but the release criteria were limited to surface contamination.
These criteria, also, would produce a dose similar to the 1-10 mrem per year l
i suggested here.
l In. summary, criteria similar to those suggested here have been used exten-sively over an extended period of time without undue hardship on parties decom-missioning nuclear facilities.
The technology for making measurements at this required level appear to be available at moderate cost.
6.0 References 1.
Conference Proceedings for the State Workshops for the Review of the ET. Nuclear Regulatory Commission's Decommissioning Policy, US NRC, NUREG/CP-0003, [ecember 1978.*
2.
Conference Proceedings for the State Workshops for the Review of the E'S. Nuclear Regulatory Commission's Decommissioning Policy, U.S.
NRC, NUREG/CP-0008, November 1979.*
3.
Plan for Reevaluation of NRC Policy on Decommissioning of Nuclear Facilities, US NRC, NUTt'G-0436, Revision 1, December 1978 and Supple-ment 1, August 190s.*
4.
R. I. Smith, G. J. Konzek and W. E. Kennedy, Jr., Technology, Safety L
and Costs of Decommissioning a Reference Pressurized Water Reactor l
Power Station, NUREG/CR-0130, Prepared by Pacific Northwest Labora-l tory for U.S. Nuclear Regulatory Commission, June 1978.*
5.
R. I. Smith and L. M. Polentz, Technology, Safety and Costs of Decom-i missioning a Reference Pressurized Water Reactor Power Station, Pre-pared by Pacific Northwest Laboratory for the U.S. Nuclear Regulatory Commission, Addendum to NUREG/CR-0130, August 1979.*
8
NUREG-0590, Revision 2 6.
H. D. Oak et al., Technology, Safety and Costs of Decommissioning a Reference Boiling Water 9eactor Power Station, NUREG/CR-0672, Pre-pared by Pacific Northwesl Laboratory for U.S. Nuclear Regulatory Commission, June 1980.*
7.
K. J. Schneider and C. E. Jenkins, Technology, Safety and Costs of Decommissioning a Reference Nuclear Fuel Reprocessing Plant, NUREG-0278, Prepared by Pacific Northwest Laboratory for U.S. Nuclear Regulatory Commission, October 1977.*
8.
C. E. Jenkins, E. S. Murphy and K. J. Schneider, Technology, Safety and Costs of Decommissioning a Reference Small Mixed Oxide Fuel Fabrication Plant.
NUREG/CR-0129, Prepared by Pacific Northwest Laboratory for U.S. Nuclear Regulatory Commission, February 1979.*
9.
E. S. Murphy and G. M. Holter, Techiology, Safety and Costs of Decom-missioning a Reference low-level Waste Burial Ground, NUREG/CR-0570, Prepared by Pacific Northwest Laboratury for U.S. Nuclear Regulatory Commission, June 1980.*
30.
H. K. Elder and D. E. Blahnik, Technology, Safety and Costs of Decom-missioing a Reference Uranium Fuel Fabrication Plant, NUREG/CR-1266, to be puolished ca September 1980.
11.
Draft Generic Environmental Impact Statement on Uranium Milling, U.S.
NRC, NUREG-0511, April 1979. **
12.
E. B. Moore, Jr. Facilitation of Decommissioning of Light Water Reactors, NUREG/CR-0569, December 1979."
13.
H. W. Dic.kson and Others, Progress Report on Monitoring for Compliance with Decommissioning Criteria, ORNL/HASRD-78, May 1980.***
14.
Robert S. Wood, Draft Assuring the Availability of Funds for Decom-missioning_ Nuclear Facilities, US NRC, NUREG-0584, Revision 1, November 1979.^^
15.
Enrico F. Conti, Draft Residual Activity Limits for Decommissioning Nuclear Facilities, US NRC.
NUREG-0613, September 1979.**
16.
Financial Strategies for Nuclear Power Plant Decommissioning, Temple, Barker and Sloane, Inc., NUREG/CR-1481, July 1980. "
17.
Draft Generic Environmental Imaact Statement or Decommissioning Nuclear Facilities, US NRC, NU4EG-0586.
To be published ca January 1981.
18.
Federal Register, Vol. 44 p. 50012, August 24, 1979.
19.
M. W. Young and K. F. Eckerman, A Methodology for Calculating Residual Radioactivity Levels Following Decommissioning, USNRC, NUREG-0707, to be published in August 1980.
20.
Utilization of Excess and Disposal of Surplus Personal Property
{Ifandbook), Appendix 5170, USAEC; September ?O, 1963 (Available in USNRC, N51ic Document Room).
9 1
NUREG-0590, Revision 2 21.
Letter from Director of Operational Safety to Managers and Heads of Division,USAEC,
Subject:
Real Property - Radiation Contamination Clearance, January 15, 1972.
(Available in USNRC, Public Document Room).
22.
Regulatory' Guide 1.86 " Termination of Operating Licenses for Nuclear Reactors, USNRC, June 1974.
k
- Available for purchase from the NRC/GP0 Sales Program, U.S. Nuclear Regulatory Commission, Washington, DC 20555, and the National Technical Information Service, Springfield, VA 22161.
- Available free upon written request to the Division of Technical Information and Document Control, U.S. Nuclear Regulatory Commission, Washington, DC 20555.
- Available in the NRC Public Document Room for 'aspection and copying for a fee.
10
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NUREG-0590 Rev.2 i
Thoughts on Regulation Changes
- for Decommissioning 1
! Draft Report i
1 G. D. Calkins i
Office of Standards Dsvclopment U.S. Nuclear Regulatory Commission a ma p
oq,?
.7, g
8 l
i NUREG-0590 Rev.2 Thoughts on Regulation Changes for Decommissioning Draft Report 1
Manuscript Completed: July 1980 Dr.ta Published: August 1980 G. D. Calkins Divition of Engineering Standards Office of Standards Development U.S. Nuclear Regulatory Commission W21hington, D.C. 20565
,+"* %
N' NOTE: Any opinions or conclusions contained in this paper are those of the author and do not represent official NRC policy.
NUREG-0590, Revision 2 CONTENTS PAGE
1.0 INTRODUCTION
1 2.0 SCOPE AND PURP0SE..........................................
1 3.0 TERMIN0LOGY........................................................
2 3.1 Definition of Decommissioning.................................
2 3.2 Definitions of Decommissioning Alternatives...................
2 4.0 AMENDMENT VS. NEW RULE....................
3 5.0 MAJOR ISSUES.......................................................
3 5.1 Alternatives and Timing.......................................
4 5.2 Planning......................................................
5 5.3 Financial Assurance...........................................
6 5.4 Radioactive Residues.............................
7
6.0 REFERENCES
8 111
NUREG-0590, Revision 2 1.0 Introduction l
During the State Workshops on Decommissioning of 19781 and 19792 the key sources of information resulting from the implementation of NRC's reevaluation of decommissioning policy and regulations were reviewed and discussed.
These of reevaluation, published origin-3 sources were those described in the NRC plan ally in March 1978 and revised in December 1978 to reflect comments to date including those from the 1978 State Workshops and again in July 1980 to update schedules and information.
In brief these sources of information have included the following:
1.
Technical information reports by our major contractor, Battelle PNL, on the technology safety and costs of decommissioning various nuclear 7
facilities.
These included the PWR4'5' BWR,8 fuel reprocessing plant5 mixed oxide Tuel fabrication plants and low level waste burial ground and uranium oxide fuel fabrication plant.to The uranium mill was
~
covered by its' draft Generic Environmental Impact Statement.11 A report has been completed in the facilitation of decommissioning light water reactors.12 2.
Technical information by a second contractor, ORNL, on the technology 13 of deccmmissioned facilities.
and costs of terminal radiation surveys 14 3.
Preliminary NRC staff studies of key issues:
financial assurance i
and radioactive residues.ts The staff report on financial assurance has been supplemented by a contractor report.18 4.
A summary from a preliminary draft generic environmental impact 17 statement on decommissioning prepared by the NRC staff with assist-ance from Battelle PNL.
The information base is partially, but not seriously, incomplete.
The 1
major shortcomings are with some of the detailed technical reports which are not finished.
These include the studies on a nuclear energy center with multiple reactors, non-fuel' cycle nuclear facilities, uranium hexafluoride conversion plants, and fuel storage facilities.
All of these studies except the fuel storage and uranium hexafluoride conversion facilities have been initiated.
l In all cases sufficient information was available to allow the required safety Land cost evaluations to be made as a part of the environmental impact state-ment.17 The radiological problems in handling uranium in a fluoride conversion plant and fuel storage facility are similar enough to those of handling uranium in a fuel fabrication plant to allow the needed estimates'to be made.
2.0 Scope and Purpose-The scope.of this paper includes all nuclear facilities except uranium l
mills and their associated tailings piles, high level waste repositories and low level waste burial grounds.
Rulemaking is already underway for these.
Proposed' regulations in the licensing of uranium mills have been announced.ts In the case of high level waste repositories and low level waste burial grounds proposed regulations are in the process of being drafted as new Parts 60 and l-61 to the Title 10 Code of Federal Regulations. -Decommissioning will be covered in each of these regulations.
NUREG-0590, Revision 2 The purpose of this paper is to summarize the preliminary thoughts of the decommissioning staff in the Office of Standards Development at NRC and to stimulate participation of others relative to decommissioning regulatory changes.
These preliminary thoughts have resulted from evaluations of the information base described above.
It is emphasized that these preliminary thoughts do not represent a broad consensus yet.
The purpose here is to solicit comments and suggestions from a wide audience.
Although this paper was prepared initially for the State Workshops on Decommissioning in September 1979, it is also being used to stimulate participation from the public, the NRC staff broadly and other government agencies as well as the States.
This paper is revised here to update the information in the Introduction on the information base, to add a new section on terminology, and to make important additions to the key issues, Section 5.3 on financial assurance and Section 5.4 on radioactive residues.
Anyone interested in commenting on this paper, on the information base used as background for this paper or on any matter concerning decommissioning of nuclear facilities is invited to send them to:
1 G. D. Calkins Decommissioning Program Manager Office of Standards Development U.S. Nuclear Regulatory Commission Washington, D.C.
20555 All comments will be included in the record of consideration by the Commission l
in establishing criteria and new standards for decommissioning.
3.0 Terminology l
Some confusion and misunderstanding has resulted from the variation of l
terminology used in the decommissioning field.
For example, the words dacom-l mission, decontaminate ar.d dismantle have been used interchangeably for the l
decommissioning alternative consisting of the immediate removal of all radio-l active material to permit unrestricted release of the property.
The word l
dismantlement has been used to describe decontamination activitics that involve l
no actual dismantlement.
Similarly, the words safe storage, protective storage, lay-away, mothball and temporary entombment have been used to name the alterna-tive of decommissioning consisting of placing and maintaining property safely in storage as a precursor to final decommissioning.
In the interest of ending the confusion it appears desirable to strictly define decommissioning and the major alternatives for accomplishing it.
Furthermore the use of pseudoacronyms for the alternative avoids words which may have several meanings.
3.1 Definition of Decommissioning l
l-Decommission means to remove the property safely from service and dispose l
of the radioactive residue.
3.2 Definitions of Decommissioning Alternatives DECON means to immediately remove all radioactive material to permit unrestricted release of the property.
2
~
NUREG-0590, Revision 2 SAFSTOR means to fix and maintain property so that risk to safety is acceptable for the period of storage followed by decontamination and/or decay to an unrestricted level.
ENT0MB means to encase and maintain property in a strong and structurally long-lived material (e.g., concrete) to assure retention until radioactivity decays to an unrestricted level.
4.0 Amendment vs New Rule Collectively these studies and evaluations (see Section 1.0) suggest to the author that all nuclear facilities will require consideration in rulemaking revisions on decommissioning.
Current regulations cover the requirements and criteria for decommissioning in only a limited fashion.
For many types of nuclear facilities the rules are mute.
The rulemaking for decoramissioning could be accomplished as a separate part of NRC's regulations.
However, the proposed action would directly affect licensing activities under Parts 30, 40, 50 and 70 of Title 10 of the Code of Federal Regulations (10 CFR).
This implies that amendments to the separate parts rather than a separate new part would be less disruptive of existing procedures and processes.
It appears that the parts shown below will require amendment:
Parts of 10 CFR Requiring Amendment Part No.
Title 20 Standards for Protection Against Radiation 30 Rules of General Applicability to Domestic Licensing of Byproduct Material 40 Domestic Licensing of Source Material 50 00mestic Licensing of Production and Utilization Facilities 70 Domestic Licensing of Special Nuclear Material 51 Licensing and Regulatory Policy and Procedures for Environmental Protection 5.0 Major Issues Furthermore, the various studies and evaluations show that there are five major areas of decommissioning which should be addressed in the amendments:
1 1.
Alternatives 2.
Timing 3.
Planning 3
NUREG-0590, Revision'2 l
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4.
Financial Assurance l
5.
Residual Radioactivity l
l The issues of alternatives'and timing will be discussed together below since they are very closely related.
l 5.1 Alternatives and Timing l
Generally, the primary goal of decommissioning of nuclear facilities should l
be DECON, (immediate removal of the radioactivity and release of the property on an unrestricted basis) at the earliest practical date.
In some cases DECON may not be most effective because occupational exposures may be reduced by using SAFSTOR, (safe storage to allow some decay of the radioactivity followed by decontamination or by using ENTOMB (entombment) to allow decay of the radio-activity in about 100 years to unrestricted levels.
The technical studies of the decommissioning of the various nuclear facili-l ties suggest toe the author three major classifications of alternatives and timing.
These are based on the half life of the most critical and/or abundant nuclides l
involved:
1.
Half life of about 5 years.
Cobalt-60 is an example of this case, l
and it is the critical / abundant nuclide for nuclear reactors.
The l
following decommissioning actions would be permitted:
a.
DECON if occupational exposures are properly managed.
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b.
SAFSTOR with surveillance for up to about 30 years followed by l
delayed decontamination unless the radioactivity decays to an j
unrestricted level.
c.
ENT0MB with surveillance for about 100 years if the radioactivity will decay to enrestricted levels.
This is not the case for reactors which may contain excessive amounts of long lived nuclides such as niobium-94 and nickel-59.
l A preliminary and partial study 17 of the decommissioning of a l
nuclear center having multiple reactors indicates that the above criteria are valid there as well as for a single reactor site.
2.
Half life of about 30 years. The fission products strontium-90 and cesium-137 are examples of this case and they are the critical /abun-l dant nuclides for a fuel reprocessing plant.
The following decom-missioning actions would be permitted:
a.
DECON if occupational exposures are properly managed.
b.
SAFSTOR with surveillance for about 100 years followed by delayed decontamination unless the radioactivity decays to an unrestricted level.
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NUREG-0590, Revision 2 3.
Half life greater than about 30 years.
The following decommission-ing action would be permitted:
a.
DECON.
5.2 Planning Decommissioning plans will be required of the applicants / licensees for all nuclear facilities.
The extent of this planning will increase with the complexity of the facility.
Initial and final planning will be permitted.
In
.these cases initial plans wi'l be required at the time of license application and final plans at the time of written notification of NRC of the licensee's intention to discontinue the activities covered by the license.
5.2.1 Initial Plans Initial plans will include the following:
1.
Alternative Tentative selection and description of the alternative for decom-missioning will be made. This must be in sufficient detail to identify the approximate cost of the decommissioning activity to be used in connection with the financial qualification requirements.
Such cost estimates may be based on acceptable information from the literature such as that from Battelle PNL.
2.
Facilitation Description of facility design and operational features intended to facilitate decommissioning.
Battelle PNL has completed a technical study on the facilitation of reactor decommissioning.12 3.
Records Description of plans for the licensee to collect and safeguard records and archive files to support decommissioning.
This will include com-plete as-built and as-revised drawings and specifications, significant opera-tional occurrences, and site specific background data.
)
5.2.2 Final Plans The final decommissioning plans will be in much greater detail.
They 1
l' will be submitted in sufficient time to permit review and approval by NRC prior
+
to the initiation of any' actual decommissioning activity.
The lead time for this review will vary with the complexity of the facility.
For example, it would be a year for a major power reactor.
Final plans will include the following:
1.
Alternative Final-selection of the alternative of decommissioning will'be made.
This should include a detailed description including the major procedures and techniques related to the safety of the operation.
Plans for processing
.and disposing of all. wastes will be discussed.
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Schedule Detailed schedules for completion of all decommissioning activi-ties will be submitted.
3.
Administrative Controls i
l The plan should describe the organization and procedures for accomplishing the decommissioning.
It should delineate responsibilities and the requirements for review, audit and reporting.
The quality assurance pro-gram to be applied should be presented in detail.
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4.
Specifications t
l The licensee will be expected to develop, evaluate and propose l
controls and limits to assure occupational and public safety.
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S.
Training Details will be needed on a program for training of employees and contractor personnel.
I 5.3 Financial Assurance Generally, the goals in the area of financing the decommissioning of nuclear facilities should be to provide a very high degree of assurance that the licensee will pay the costs and to allow a wide latitude of approaches to implement that assurance. " The costs for decommissioning various nuclear facilities are not well established bet.ause there has been only limited actual experience.
In order to provide more reliable cost data NRC has had Battelle l
PNL make detailed estimates for most nuclear facilities.
These estimates or comparable ones are satisfactory guidelines for these purposes.
Of course, the information on costs is expected to improve with time, and it is planned l
to require periodic reviews of the cost estimates to correct them as appropriate.
Three basic approaches, used singly or in combination, to implement the assurance appear satisfactory:
1.
Prepayment.
Cash or other liquid assests that will retain their value j
for the projected operating life of the facility may 'se deposited into a segre-i gated account prior to facility startup.
Prepayment will probably be the only satisfactory alternative to cover costs involving long term surveillance.
2.
Sureties.
bonds, letters of credit and lines of credit that guaran-i tee that the costs will be paid may be used.
It appears questionable that bonds i
of the sizo and for the time involved with power reactors will be available.
However, tney. appear to be available for facilities that involve smaller costs and periods.
l 3.
Sinking Funds and Insurance.
The sinking fund or funded reserve requires a prescribed amount of funds, subject to annual revision, be set aside annually such that the fund plus accumulated interest would be sufficient to pay.for the costs at the time of decommissioning.
The weakness of the sinking fund approach is that in the. event of premature shutdown the decommissioning 6
NUREG-0590, Revision 2
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fund would be insufficient.
Therefore, the sinking fund would have to be sup-l plemented by insurance which would pay the difference.
There is some indica-tion that such insurance could be made available."
Some reviewers, mainly those associated with nuclear power plants, of the above approaches to financial assurance have voiced concern that the options of an unsegregated sinking fund, negative salvage, or payment at the time of decommissioning are not included.
Their major argument is that options selected are more expensive.
While this is true, none of the options signifi-cantly increase the cost to consumers.
The total cost of decommissioning increases the cost of nuclear power to consumers by approximately 2 to 5 per-18 cent.18 While a segregated sinking fund may be twice as expensive as payment at the time of decommissioning it is not significantly more costly to consumers.
5.4 Radioactive Residues Discussions with the staff at EPA relative to acceptable radioactive resi-due limits indicate that:
1.
potential doses from decommissioned facilities should be less than those from operating ones, 2.
doses (whole body equivalent) above about 5 mrem per year are probably unacceptable, 3.
justification would be required for doses more than one mrem per year, and 4.
a plan for complying with these criteria could utilize realistic rather than conservati1e pathway analysis.
Realistic analyses involve recognition that occupancy is less than 100 percent of the time, that the source of sustenance is not limited only to the decommissioned site, that self shielding reduces the dose and that resuspension is decreased by weathering as a function of time.
As considerations of the application of the above criteria to various nuclear facilities has progressed, it has become clear that a dose range is more practical than a specific dose.
For some nuclide mixes and facilities it cay be impractical and unnecessary to meet the 5 mrem per year criteria.
It appears that a goal for the release of decommissioned property on an unrestricted basis should be for potential exposure to an individual as low as reasonably achievable in the range of 1 to 10 mrem per year.
Technical and/or economic l
justification may be required.
l l
The applicat. ion of the above criteria requires the ability to convert the doses in mrem per year to contamination levels in terms of surface or volumetric concentration of radinactivity.
A methodology for doing this was recently com-pleted.19 Reviewers of this proposed goal have expressed concern that radiation cannot be detected or that it would be prohibitively expensive to make measurements et that level.
These concerns do not seem to be well founded as shown below:
7
NUREG-0590, Revision 2 Recent preliminary work 13 has been completed at ORNL on the terminal radia-tion survey for the case of the decommissioning an 1175 MWe PWR.
This study shows that the technology is readily available to make a statistically-designed, terminal radiation survey with a reasonable degree of confidence and at a moder-ate cost, less than $250,000 at the 5 mrem per year level.
This cost represents only a fractior of a percent of the total cost of decommissioning a large reactor.
Furthermore, it indicates that the cost at a release level of a dose of 25 mrem per year is only about 10 percent less than the 5 mrem per year case.
It was found that the cost at a release level of a dose of 1 mrem per year would be extremely high and not easily estimated.
In addition, a historical review shows that in the 1960's that written criteria for acceptable level of radioactive residues for the release of decom-missioned property did exist and were utilized.19,20 The criteria were based on a goal of a limiting exposure to a few percent of the radiation protection standard of 500 mrem per year in an uncontrolled area.
Such radiation rates are similer to those expressed as a dose of 1-10 mrem per year.
Unfortunately, it was decided in 1973 to drop the written criteria and go on a case-by-case basis for the release of property.21 This lack of written criteria resulted in confusion and inconsistency which still continues.
22 In 1974 guidance for termination of reactor licenses was issued (Regula-
)
tory Guide 1.86), but the release criteria were limited to surface contamination.
These criteria, also, would produce a dose similar to the 1-10 mrem per year suggested here.
In summary, criteria similar to those suggested here have been used exten-sively over an extended period of time without undue hardship on parties decom-missioning nuclear facilities.
The technology for making measurements at this required level appear to be available at moderate cost.
6.0 References 1.
Conference Proceedings for the State Workshops for the Review of the U.S. Nuclear Reculatory Commission's Decommissioning Policy, US NRC, NUREG/CP-0003, [ecember 1978.*
2.
Conference Proceedings for the State Workshops for the Review of the U.S. Nuclear Regulatory Commission's Decommissioning Policy, U.S.
NRC, NUREG/CP-0008, November 1979.*
3.
Plan for Reevaluation of NRC Policy on Decommissioning of Nuclear Facilities, US NRC, NUREG-0436, Revision 1, December 1978 and Supple-ment 1, August 1980.*
i 4.
R. I. Smith, G. J. Konzek and W. E. Kennedy, Jr., Technology, Safety and Costs of Decommissioninc a Reference Pressurized Water Reactor Power Station, NUREG/CR-0130, Prepared by Pacific Northwest Labora-tory for U.S. Nuclear Regulatory Commission, June 1978.*
5.
R I. Smith and L. M. Polentz, Technology, Safety and Costs of Decom-missioning a Reference Pressurized Water Reactor Power Station, Pre-pared by Pacific Northwest Laboratory for the U.S. Nuclear Regulatory Commission, Addendum to NUREG/CR-0130, August 1979.*
8
NUREG-0590, Revision 2 6.
H. D. Oak et al., Technology, Safety and Costs of Decommissioning a Reference Boiling Water Reactor Power Station, NUREG/CR-0672, Pre-pared by Pacific Northwest Laboratory for U.S. Nuclear Regulatory Commission, June 1980.*
7.
K. J. Schneider and C. E. Jenkins, Technology, Safety and Costs of Decommissioning a Reference Nuclear Fuel Reprocessing Plant, NUREG-0278, Prepared by Pacific Northwest Laboratory for U.S. Nuclear Regulatory Commission, October 1977.*
8.
C. E. Jenkins, E. S. Murphy and K. J. Schneider, Technology, Safety and Costs of Decommissioninc a Reference Small Mixed Oxide Fuel Fabrication Plant.
NUREG/CE-0129, Prepared by Pacific Northwest Laboratory for U.S. Nuclear Regulatory Commission, February 1979.*
9.
E. S. Murphy and G. M. Holter, Technology, Safety and Costs of Decom-missioning a Reference Low-level Waste Bur _ial Ground, NUREG/CR-0570, Prepared by Pacific Northwest Laboratory far U.S. Nuclear Regulatory Commission, June 1980.*
10.
H. K. Elder and D. E. Blahnik, Technology, Safety and Costs of Decom-l missioing a Reference Uranium Fuel Fabrication Plant, NUREG/CR-1266, to be published ca September 1980.
11.
Draf t Generic Environmental Impact Statement on Uranium Milling, U.S.
NRC, NUREG-0511, April 1979.**
12.
E. B. Moore, Jr. Facilitation of Decommissioning of Light Water Reactors, NUREG/CR-0569, December 1979."
13.
H. W. Dickson and Others, Progress Report on Monitoring for Compliance with Decommissioning Criteria, ORNL/HASRD-78, May 1980.***
14.
Robert S. Wood, Draft Assuring the Availability of Funds for Decom-missioning Nuclear Facilities, US NRC, NUREG-0584, Revision 1, November 1979.""
15.
Enrico F. Conti, Draft Residual Activity Limits for Decommissioning Nuclear Facilities, US NRC.
NUREG-0613, September 1979.""
16.
Financial Strategies for Nuclear Power Plant Decommissioning, Temple, Barker and Sloane, Inc., NUREG/CR-1481, July 1980."
17.
Draft Generic Environmental Imaact Statement or Decommissioning Nuclear Facilities, US NRC, NUREG-0586.
To be published ca January 1981.
18.
Federal Register, Vol. 44 p. 50012, August 24, 1979.
19.
M. W. Young and K. F. Eckerman, A Methodology for Calculating Residual Radioactivity Levels Following Decommissioning, USNRC, NUREG-0707, to be published in August 1980.
20.
Utilization of Excess and Disposal of Surplus Personal Property (Handbook), Appendix 5170, USAEC; September 20, 1963 (Available in USNRC, Public Document Room).
9
NUREG-0590,' Revision 2 21.
Letter from Director of Operational Safety to Managers and Heads of Division,USAEC,
Subject:
Real Property - Radiation Contamination Clearance, January 15, 1972.
(Available in USNRC, Public Document Room).
22.
RegulatorgGuide1.86"TerminationofOperatingLicensesforNuclear Reactors, USNRC, June 1974.
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)
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- Available for purchase from the NRC/GP0 Sales Program, U.S. Nuclear Regulatory Commission, Washington, DC 20555, and the National Technical Information Service. Springfield, VA 22161.
- Available free upon written request to the Division of Technical Information and Document Control, U.S. Nuclear Regulatory Commission, Washington, DC 20555.
- Available'in the NRC Public-Document Room for inspection and copying for a fee.
10-2
r NUREG-0590, REV. 2 THOUGHTS ON REGULATION CHANGES FOR DECOMMISSIONING AUGUST 1980 I
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