ML23156A069
| ML23156A069 | |
| Person / Time | |
|---|---|
| Issue date: | 07/13/1990 |
| From: | Hoyle J NRC/SECY |
| To: | |
| References | |
| PRM-060-003, 55FR28771 | |
| Download: ML23156A069 (1) | |
Text
ADAMS Template: SECY-067 DOCUMENT DATE: 07/13/1990 TITLE: PRM-060-003 - 55FR28771 - PETITION OF THE U.S.
DEPARTMENT OF ENERGY FOR A RULEMAKING TO ESTABLISH AN ACCIDENT DOSE CRITERIA FOR A HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY CASE
REFERENCE:
PRM-060-003 55FR28771 KEYWORD: RULEMAKING COMMENTS Document Sensitivity: Non-sensitive - SUNSI Review Complete
STATUS OF RULEMAKING PROPOSED RULE: PRM-060-003 OPEN ITEM {Y/N) N RULE NAME: PETITION OF THE U.S. DEPARTMENT OF ENERGY FOR A RU LEMAKING TO ESTABLISH AN ACCIDENT DOSE CRITERIA FO RA HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY PROPOSED RULE FED REG CITE: 55FR28771 PROPOSED RULE PUBLICATION DATE: 07/13/90 NUMBER OF COMMENTS: 4 ORIGINAL DATE FOR COMMENTS: 10/11/90 EXTENSION DATE: I I FINAL RULE FED. REG. CITE: 61FR64257 FINAL RULE PUBLICATION DATE: 12/04/96 NOTES ON: PET. ON DESIGN BASIS ACCIDENTS DOSE CRITERION FOR STORAGE OF HLR STATUS : WASTES IN GEO REPOSITORIES. PARTIAL GRANT/PARTIAL DENIAL BY 60FR OF R ~ t . 1519&. SEE ALSO PR-060 {60FR15180). FILE LOCATED IN 16 H17.
HISTORY OF THE RULE PART AFFECTED: PRM-060-003 RULE TITLE: PETITION OF THE U.S. DEPARTMENT OF ENERGY FOR A RU LEMAKING TO ESTABLISH AN ACCIDENT DOSE CRITERIA FO RA HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY PROPOSED RULE PROPOSED RULE DATE PROPOSED RULE SECY PAPER: SRM DATE: I I SIGNED BY SECRETARY: 07/09/90 FINAL RULE FINAL RULE DATE FINAL RULE SECY PAPER: 94-239 SRM DATE: I I SIGNED BY SECRETARY: 11/25/96 STAFF CONTACTS ON THE RULE CONTACTl: MICHAEL T. LESAR MAIL STOP: T6-D59 PHONE: 41!;;-7163 CONTACT2: MAIL STOP: PHONE:
DOCKET NO. PRM-060-003 (55FR2877 l)
In the Matter of PETITION OF THE U.S. DEPARTMENT OF ENERGY FOR A RU LEMAKING TO ESTABLISH AN ACCIDENT DOSE CRITERIA FO RA HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY
- DATE DOCKETED DATE OF DOCUMENT TITLE OR DESCRIPTION OF DOCUMENT 04/25/90 04/19/90 PETITION OF THE U.S. DEPARTMENT OF ENERGY FOR A RULEMAKING TO ESTABLISH AN ACCIDENT DOSE CRITERIA FOR A HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY 07/10/90 07/09/90 FEDERAL REGISTER NOTICE - RECEIPT OF PETITION FOR RULEMAKING 08/07/90 08/03/90 FR NOTICE - PETITION FOR RULEMAKING; NOTICE OF RECEIPT, CORRECTION (PUBLISHED 8/10/90 55FR32639) 10/10/90 10/01/90 COMMENT OF CONCERNED U.S. CITIZEN ( 1) 10/12/90 10/11/90 COMMENT OF EDISON ELECTRIC INSTITUTE & UTILITY NUCLEAR WASTE (LORING E. MILLS) ( 2) 10/15/90 10/09/90 COMMENT OF LINCOLN COUNTY & CITY OF CALIENTE, NV (MIKEL. BAUGHMAN) ( 3) 11/29/90 11/26/90 COMMENT OF DEPARTMENT OF ENERGY (JOHN W. BARTLETT) ( 4)
03/16/95 03/15/95 FEDERAL REGISTER NOTICE - PARTIAL GRANT/PARTIAL DENIAL OF PETITION FOR RULEMAKING 12/02/96 11/25/96 FINAL RULE PUBLISHED AT 61FR64257 ON 12/04/96 ADDR ESSED PR-060 (60FR15180) AND PRM-060-003.
DOCKET NUMBER ~.
PETITION RULE PRM *~ - 7590-01-P DOCKE TED u ~n:c
( S5 Ft< :).877!) -
'96 0[ 0 -2 A1 G:38 NUCLEAR REGULATORY COMMISSION 0FF ICE C;- SF. C '::: TJ'.1,RY OO CKE 11 *., -x .: .: RVICE 10 CFR Part 60 W{A CF RIN: 3150-ADSl Disposal of High-Level Radioactive Wastes in Geologic Repositories; Design Basis Events AGENCY: Nuclear Regulatory Commission.
ACTION: Final rule.
SUMMARY
- The Nuclear Regulatory Commission is amending its regulations on the protection of public health and safety from activities conducted at a geologic repository operations area (GROA) before permanent closure. In particular, the final rule
- addresses the measures that are required to provide defense in depth against the consequences of "design basis events." These measures include prescribed design requirements, quality assurance requirements, and the establishment of a preclosure controlled area from which members of the public can be excluded.
1 EFFECTIVE DATE: ~MIVllf .3 , 199¢ (30 days from date of publication in the Federal Register].
FOR FURTHER INFORMATION, CONTACT: Dr. Richard A. Weller, Division of Waste Management, Office of Nuclear Material Safety p~ , /JY1 /!J./<1-/t10 a:/; ~I Ff IPt/251
and Safeguards, U.S. Nuclear Regulatory Commission, Washington, DC 20555, telephone (301) 415-7287.
SUPPLEMENTARY INFORMATION:
Background
Under the Nuclear Waste Policy Act of 1982, as amended, the U . S . Nuclear Regulatory Commission exercises licensing and related regulatory authority with respect to geologic repositories that are to be constructed and operated by the U.S. Department of Energy (DOE) for the disposal of high-level radioactive waste . The Commission's regulations pertaining to these geologic repositories appear at 10 CFR Part 60. In recent years, NRC, in conjunction with its Federally-Funded Research and Development Center, the Center for Nuclear Waste Regulatory Analyses, completed a comprehensive review of the r~quirements of Part 60 regarding their clarity and sufficiency to protect public health and safety. NRC focused particular attention on any matters that may be ambiguous, insufficient for their intended purpose, or inconsistent with other expressions of its regulatory policy. Independently, DOE conducted a similar review of Part 60.
The NRC review identified deficiencies regarding the clarity and sufficiency of the current Part 60 requirements to protect 2
public health and safety for the full range of credible conditions or events that may occur at an operating repository, including those low-probability events that have potentially serious consequences. NRC also noted that certain elements of existing Part 60 differ from counterpart requirements in other NRC rules where greater consistency in language would be beneficial. OOE's independent review of Part 60 requirements identified similar deficiencies in these requirements. To
- address these issues, DOE filed a petition for rulemaking (PRM),
PRM-60-3, on April 19, 1990.
In response to the DOE petition and the results of the NRC review of Part 60, the Commission published a proposed rule for public comment in the Federal Register on March 22, 1995 (60 FR 15180) to clarify the requirements for protection of public health and safety related to activities conducted at a GROA be~ore its permanent closure. In particular, the proposed rule provided new and modified definitions for certain terms (including the definition of "important to safety," with reference to structures, systems, and components), dose criteria for accident conditions, and requirements for the establishment of a preclosure controlled area from which members of the public can be excluded when necessary. In an accompanying notice (March 22, 1995; 60 FR 15190) the Commission also granted in part, and denied in part, the specific proposals in the DOE petition. For a fuller discussion of the PRM, the proposed rule, 3
.and the partial grant/partial denial of the DOE petition, see the Federal Register notices cited above. As noted in the Federal Register notice for the proposed rule (60 FR 15180) and as intended in subsequent discussions in this notice, unless the specific context suggests otherwise, the terms "provisions,"
"requirements," "standards," and "criteria" are generally used interchangeably; the term "limit" (as in "dose limit") is generally used to refer to a specific type of requirement or criterion; and the term "rule" is generally used to refer to the entire set of requirements or criteria (e.g., Part 60) This final rule completes NRC action related to PRM-60-3.
Lastly, the Commission notes that, consistent with the mandates of the Energy Policy Act of 1992, the Environmental Protection Agency (EPA) is developing site-specific environmental radiation protection standards for a potential repository at Yucca Mountain, Nevada. In this regard, the Act specifies that, within one year after promulgation of the EPA standards, the Commission must promulgate a rule so that Commission regulations are consistent with the new EPA standards. Although the primary focus of the new EPA standards is on the postclosure period of repository performance, the staff will ensure that the current modifications to Part 60 proposed herein, which focus on the period of repository operations before permanent closure, are consistent.with the new EPA standards. To the extent any inconsistencies between NRC and EPA requirements are identified, 4
they will be addressed in the planned future rulemaking by NRC to address new EPA standards.
Public Comments on the Proposed Rule A period of 90 days was specified in the Federal Register for public comments on the proposed rule. The Commission specifically sought public comments on: (1) the appropriateness
- , of the proposed 0.05 Sv (5 rem) dose limit in new 10 CFR 60.136 as the repository design basis for protection of public health and safety during accident conditions, and (2) the rationale supporting the proposed 0.05 Sv (5 rem) dose limit. Ten sets of comments were received on the proposed rule from the following organizations and individuals: (1) The Clean Water Fund of North Carolina (CWFNC); (2) Mr. Vernon J. Brechin; (3) DOE, Office of Civilian Radioactive Waste Management; (4) EPA, Office of Federal
- Activities; (5) Nye County, Nevada, Nuclear Waste Repository Project Office; (6) Virginia Power Company; (7) Nuclear Energy Institute (NEI); (8) Environmental Coalition on Nuclear Power (ECNP); (9) Wisconsin Electric Power Company; and (10) Mr. Marvin I. Lewis.
The principal issues raised in the comments are summarized below. (Comments that are duplicative, editorial, or beyond the scope of the rulemaking are not discussed herein but have been considered in the analysis of the public comments.) For the 5
.reasons indicated, the Commission has decided to adopt the amendments substantially in the form proposed in the March 22, 1995, Federal Register notice (60*FR 15180) but with the changes noted that reflect the Commission's analysis of the public comments.
- 1. Controlled Area - Waste Isolation.
DOE noted that the supplementary information in the proposed rule referred to the "controlled area" as one" ... (within which waste isolation is to be ensured after permanent closure)," DOE observed that this. is inconsistent with the Part 60 definition of "controlled area," which does not refer to waste isolation. DOE recommended that the Commission delete the parenthetical phrase in the supplementary information.
The Commission agrees that the parenthetical phrase does not properly char~cterize the definition of "controlled area."
However, rather than deleting the parenthetical phr~se altogether, the Commission.has modified the phrase to accurately reflect the definitio~ of "controlled area" and its focus on postclosure activities.
- 2. Multiple Failure Scenarios ..
DOE noted that the supplementary information under §60.136 6
.seemed to indicate that multiple independent failure scenarios would be considered to be Category 2 design basis events and observed that, typically, nuclear safety analyses are not required to assume multiple failures of safety-related systems unless they are all credible consequences of the initiating event. DOE recommended that the Commission clarify how it intendi to review the acceptability of repository systems, structures, and components in the context of the new rule.
The Commission agrees with this comment and has revised the supplementary information to clarify how it intends to review the analysis in the DOE license application to demonstrate compliance with the requirements of §60.136.
- 3. Probability Bounds for Design Basis Events.
In the Section-by-Section Analysis of §60.136 in the proposed rule, the Commission indicated that the lower bound for Category 2 design basis events is on the order of 1 x 10- 9 per year (i.e., events with probabilities of occurrence less than 1 x 10- 9 per year would generally be screened from further consideration due to their negligible contribution to overall risk). DOE and NEI objected that this lower bound is much too low and unjustified. DOE recommended a lower bound of 1 x 10- 6 per year and NEI recommended a lower bound in the range of 1 x 10- 6 per year to 1 x 10- 7 per year. On the other hand, ECNP 7
_recommended that the most improbable sequences and combinations of events and accidents (Category 2 and beyond) should be evaluated in repository accident analysis.
The Commission agrees with DOE and NEI that the lower probability bound discussed in the proposed rule for Category 2 design basis events is too low and is unjustified. The Commission considers that, on the basis of repository risk perspective, a lower probability bound of 1 x 10- 6 per year is appropriate for these events. The Commission recognizes that the estimated consequences from Category 2 design basis events are somewhat limited and would not likely exceed several tenths of Sv (several tens of rem). At this consequence level, the estimated risk of cancer fatality from events with a probability lower than 1 x 10- 6 per year is less than 1 x 10-s per year. To put this risk in perspective, the International Commission on Radiological Protection1 notes that a fatal cancer risk in the range of 1 x 10- 6 to 1 x 10-s per year from exposure to radiation would likely be acceptable to members of the public. As such, Category 2 design basis events which result in fatal cancer risks on the order of 1 x 10-s per year or lower do not contribute significantly to individual risk. Accordingly, events with probabilities of occurrence lower than 1 x 10- 6 per year can be screened from further consideration in repository risk analysis.
Recommendations of the International Commission on Radiological Protection. ICRP Publication 26, January 1977.
8
The Commission has revised the Section-by-Section Analysis of §60.136 to reflect a lower bound for Category 2 design basis events on the order of 1 x 10- 6 per year.
- 4. Definition of "Important to Safety" - Engineered Features.
DOE noted that the phrase "engineered structures, systems,
- arid components," currently in the definition of "important to safety," was removed from the new definition and observed that it is clearly the intent of the regulation to apply the definition to engineered systems, not natural systems.
The Commission agrees with this comment and has revised the
, definition of "important to safety" to clarify this intent.
- 5. Applicability of Environmental Protection Agency Standards to the Management and Storage of High-Level Waste.
DOE stated that the proposed rule did not address all of the regulatory uncertainty associated with dose limits for design basis events because both the existing rule and the proposed rule appear to require compliance with both EPA radiation protection standards and Part 20 radiation standards and there is an inconsistency between these two standards. Virginia Power noted 9
that the definition of "important to safety" establishes the Part 20 limits that are referenced in 10 CFR 60.lll(a) as the acceptance criteria for the Category 1 design basis events and concluded that this seems to be inappropriate. Virginia Power stated that Part 20 establishes occupational dose limits and radiation dose limits for members of the public, that these limits are expressed as annual limits, and that these limits are associated with normal licensed activities - not design basis events. Virginia Power considered that it is not appropriate to use Part 20 limits to evaluate specific.events. Virginia Power further considered that acceptance criteria for design basis events are associated with the specific consequences of those events, as for example in §60.136 for the Category 2 design basis events, 'and that appropriate acceptance* criteria will need to be developed if Category 1 design basis events are retained by the final rule.
The Commission agrees with DOE that both the dose limits and the methodology for calculating doses to members of the public in the EPA standards differ from the dose limits and methodology for calculating doses to members of the public in Part 20, Subpart D.
Notwithstanding the differences between these s~andards, the.
staff does not consider that there is any regulatory uncertainty regarding applicable dose limits for Category 1 design basis events. In DOE's demonstration of compliance, either the EPA standards or the Part 20 standards may be more limiting or 10
controlling than the other, but that does not relieve DOE of the requirement to comply with both standards. As such, the Commission has made no changes to the proposed rule to address DOE's concerns about the differences between Part 20 and the EPA standards.
The Commission disagrees with *Virginia Power that Part 20 limits are inappropriate. The Commission's numerical radiation
- protection standards are codified in Part 20 and apply to operations at a geologic repository by virtue of 10 CFR 20.1002 and §60.lll(a). However, it is not the Commission's intent that
' it is necessary to use the annual limits in Part 20 to evaluate specific Category 1 design basis events on an individual basis.
Instead the Commission intends that the sum of the annual doses, exposures, and releases from all Category 1 design basis events shall not exceed the limits specified in Part 20 and in the EPA
- s tandaro.s .
- 6. Preclosure Controlled Area.
DOE expressed a concern that the use of the word "immediately" in the definition of "preclosure controlled area" could lead to an implication that the boundary must be next to the GROA. DOE also expressed a concern that the use of the word "nearest II in §60 .136 (b) (i.e., 11
- no individual located on or beyond the !'ea:i.i~!! boundary of the preclosure controlled 11
area ... 11
) is confusing.
The Commission agrees with these comments and has:
(1) deleted the word "immediately" in the definition of 11 preclosure controlled area" in 10 CFR 60.2, (2) changed the phrase "nearest boundary" to "any point on the boundary" in the definition of "important to safety" in §60.2 and in the design requirements of the geological repository operations area in
§60.136(b).
- 7. Definition of Site.
DOE recommended that the definition of "site" should include 11 preclosure 11 and "postclosure controlled areas."
The Commission agrees with this comment and has modified the definition of "site" to reflect its meaning during the period before permanent repository closure (i.e., the operational period), as well as the period following permanent closure.
- 8. Effluent Control.
DOE stated that, with the deletion of the term "during normal operations," the application of the Part 20 effluent limits invoked by §60.lll(a) is not clear. DOE recommended that 10 CFR 60.132(c) (1) be revised to clarify that the latter section 12
-is applicable only to Category 1 design basis events.
The Commission agrees with this comment and has revised
' §60.132(c) (1) to clarify that this section is applicable only to
, Category 1 design basis events.
- 9. Criticality Control.
DOE noted that the Commission intended to clarify the requirements pertaining to criticality control, currently in 10 CFR 60.131(b} (7), but that some confusion concerning those requirements remains. DOE pointed out that the proposed criticality control requirements in §60.131(h} refer to "isolation of radioactive waste," a phrase with postclosure connotations, while noting that systems "must be designed for criticality safety assuming occurrence of design basis events," a
- phrase which has preclosure implications. Furthermore, _DOE argued that the last sentence in §60.131(h) could be interpreted as requiring a deterministic demonstration of criticality safety over the entire period of regulatory concern. However, given the time frames involved, DOE considered probabilistic analyses to be an essential part of demonstrating long-term criticality safety.
The Commission considers that the applicability of the criticality control requirements proposed in §60.131(h) is clear with respect to preclosure considerations but agrees with DOE 13
that uncertainty remains with respect to the applicability of the criticality control requirements to the postclosure period.
However, the Commission intends to address this remaining uncertainty in a future rulemaking to make the NRC requirements consistent with the revised EPA standards that are currently under development, as mandated by the Energy Policy Act of 1992.
Accordingly, in this final rule, §60.13l(h) is promulgated, as proposed in the proposed rule.
- 10. The Use of the terms "Important to Safety."
"Accidents." "Normal Conditions." "Anticipated Operational Occurrences." and "Design Basis Events" in Part 60.
CWFNC stated that there was not any ambiguity in the current use of the terms "important to safety" and "accidents" in Part 60. ECNP stated that the terms "normal conditions,"
"anticipated operational occurrences," and accidents" are not equivalent to nor adequately described by the term "design basis events."
The Commission disagrees with CWFNC that there is no ambiguity in the current use of the terms "important to safety" or "accidents" in Part 60. The latter term is undefined in Part 60, and there is uncertainty about its meaning with respect to the range of events the term encompasses. The full range. of 14
.Category 1 design basis events would not generally be considered as "accidents," especially those events occurring regularly or moderately frequently. However, certain lower frequency Category 1 events, which occur one or more times during the operating lifetime of a facility and are otherwise known as "anticipated operational occurrences," have at times been identified as "accidents." But "anticipated operational' occurrences" are conditions of normal operation which are not to
- be confused with the unlikely, but credible and potentially significant, Category 2 design basis events. As such, the current definition of "important to safety" is unclear with respect to its intended applicability to the design of structures, systems, or components for normal operations, including anticipated operational occurrences. Further, with the focus on protection of members of the public in unrestricted areas, the current definition of "important to safety" does not explicitly address protection for the occupational work force.
The uncertainty is not related to interpreting the meaning of "unrestricted area" but, rather, is related to the narrow focus of public exposure in unrestricted areas. Lastly, the value of 0.005 Sv (0.5 rem) as a dose limit in unrestricted areas for "accident" conditions lacks consistency with a corresponding limit in Part 72 and with dose values established as guidance for selected accidents (fuel handling and cask drop events) at Part 50 facilities (commercial power reactors).
15
Notwithstanding the comments offered by ECNP, the Commission considers that the definition of "design basis events" in the proposed rule does adequately define that term and that the supplementary information in the proposed rule does adequately describe the relationship between the terms "normal conditions,"
"anticipated operational occurrences," "accidents," and "design basis events." In this regard, it was the Commission's intent to supplant undefined terms in the rule (i.e., "normal conditions,"
"anticipated operational occurrences," and "accidents") with a defined term (i.e., "design basis events").
For the above reasons, the Commission has not revised the definitions in the proposed rule for "design basis events." As discussed in items 4 and 6 above, editorial changes have been made to the definition of "important to safety," but these changes are unrelated to the arguments advanced by CWFNC or ECNP.
- 11. Radiation Protection Standards.
CWFNC stated that a 0.005 Sv (0.5 rem) limit would not be overly protective of public health and safety and there is no reason to seek a weaker standard. CWFNC suggested modifying Part 20 to clarify any ambiguities in radiation protection standards for repositories. ECNP offered a number of comments related to radiation protection standards:
- The Commission should require DOE to provide design basis 16
accident analyses for more than undefined "critical design basis events, singly" and should require demonstration that doses would be kept far below the maximum permissible dose limits, with an as low as is reasonably achievable requirement at least comparable with that for operating reactors.
- The Part 60 limits must be much more stringent than for operating nuclear facilities.
- The limit of radiation exposure should be no higher than the most restrictive exposure limit that EPA imposes for any licensee or other source of regulated nuclear activity.
- A 0.005 Sv (0.5 rem) limit should be impermissible for an individual dose from a waste site.
- The most stringent level of worker protection, better than Part 20, should be required.
- Part 20 standards are not restrictive enough for the purpose of public health protection with respect to the storage and disposal of radioactive waste.
- The definitional alteration of the term "important to safety" is not adequate to assure health protection for the public because the proposed Categories 1 and 2 numerical limits for radiation exposures are based on standards that have failed to take into account the noncancer but adverse health effects of chronic low-dose radiation exposures that have been reported in the literature since development. of NRC's Part 20 revision.
17
- Extremely conservative radiation protection standards should I
- be utilized in repository design and performance criteria, and a zero release facility design goal should be required for all radioactive waste management.
- An acceptable rationale for the 0.05 Sv (5 rem) dose limit proposed in the proposed rule is totally absent.
The Commission acknowledges that the 0.005 Sv (0.5 rem) dose limit in the definition of "important to safety" in the existing -
rule could be construed to be an implicit basis for designing structures, systems, and components to prevent or mitigate the consequences of accidents at the boundary of the unrestricted area. On the other hand, the 0.005 Sv (0.5 rem) dose limit could also be interpreted more narrowly, to identify only those st_ructures, systems, and components that are subject to additional design requirements and a quality assurance program to ensure performance of intended functions. See §60. "'.31 (b) and
§60:151. In short, the 0.005 Sv (0.5 rem) dose limit in the definition of "important to safety" in the existing rule is, in the Commission's view, subject to conflicting interpretations.
As previously discussed, the Commission's comprehensive review of Part 60 identified deficiencies in both the clarity and sufficiency of requirements to protect workers and public health and safety. Among the identified deficiencies is the regulatory uncertainty created by possible conflicting interpretations that 18
could be 'given to the 0.005 Sv (0.5 rem) dose limit in the "important to safety" definitior.. described above and by the absence of an explicit design basis dose limit in Subpart E of the existing rule. An objective of this rulemaking is, therefore, to resolve the uncertainty in Part 60, as well as remedy the incomplete definition of "important to safety" that fails to address protection of both workers and members of the public during Category 1 design basis events (i.e., "normal
- conditions," including "anticipated operational occurrences") .
The Commission has addressed these deficiencies with the addition of new §60.136, which now provides explicit design basis accident
, dose criteria for repository structures, systems, and components, and modification of the definition of "important to safety" to include the broader interests of both worker and public health and safety for the full range of conditions or events that may occur before repository closure. The Commission believes that 9 these anendments, as well as the others as described herein, clarify and enhance the provisions in the rule to protect worker and public health and safety.
It was not the intent of this rulemaking to modify, in any way, the Commission's numerical radiation protection standards. As discussed earlier, these standards are codified in Part 20 and apply to operations at a geologic repository by virtue of
§20.1002, as well as §60.lll(a). The Commission believes that these standards continue to be appropriate for its licensees and 19
. provide adequate protection of worker and public health and safety at a repository. As such, comments by CWFNC and ECNP about possible modifications to the Commission's radiation protection standards as they would apply to.an operating repository are beyond the scope of this rulemaking.
The Commission agrees with ECNP that the term "critical design basis events" is undefined and, in the Section-by-Section Analysis of §60.21 of this final rule, has changed "critical design basis events" to "Category2 design basis events:" With regard to the scope of design basis accidents that should be considered in the license application, the Commission previously addressed this issue in the discussion of probability bounds for Category 2 design basis events and determined that events with probabilities of occurrence lower than 1 x 10- 6 per year could be screened from further consideration due to their negligible contribution to individual risk.
Regarding the rationale for the 0.05 Sv (5 rem) dose limit in
§60.136, the Commission continues to believe that the potential risks to members of the public from an operating repository are very small. In light of this limited risk, the 0.05 Sv (5 rem) dose limit provides an adequate margin of safety and an appropriate basis for the design of repository structures, systems, and components to prevent or mitigate the consequences of low probability, but credible events. The Commission's 20
- reasoning behind the 0.05 sv (5 rem) dose limit can be found in the Section-by-Section Analysis of §60.136 that appears later in this notice.
- 12. Exclusion of the Public from Preclosure Controlled Area.
Vernon J. Brechin objected to the use of the word "can"
- versus "will" in the description of preclosure controlled area.
The Commission disagrees with this comment. It is not the Commission's intention to generally exclude members of the public from the preclosure controlled area (which would be the "controlled area" as defined in 10 CFR 20.1003). However, access to the preclosure controlled area can be limited by the licensee for any reason (not necessarily one related to radiation protection). Within the preclosure controlled area will be a "restricted area" (as defined in §60.2 and §20.1003). Access to a restricted area must be controlled for purposes of radiation protection. Members of the public in the preclosure controlled area will be subject to the dose limits for members of the public in 10 CFR 20.1301. However, an individual who receives occupational dose in the preclosure controlled area will be 21
subject to the occupational dose limits of Part 20, Subpart C.
All doses in a restricted area are occupational doses. The size of the preclosure controlled area is not specified by the regulations because it will be dependent upon the particular activities conducted during the operational period.
- 13. Definition of Design Basis Events.
Virginia Power and NEI recommended that the definition of "design basis events" should make clear that the normal operations associated with receiving, handling, packaging, storing, emplacing, and retrieving high-level waste are not design basis events.
The Commission disagrees with this comment. It is the Commission's intent that events occurring regularly or frequently during the course of normal operations are considered as Category 1 design basis events. Category 1 design basis events effectively embody repository activities and conditions previously identified in Part 60 as "normal operations, including anticipated operational occurrences." In this regard, the Commission intends the Part 20 dose limits to be applicable to the conduct of repository activities, such as receiving, 22
-handling, packaging, storing, placing, and retrieving high-level waste.
- 14. Definition of "Important to Safety" - Function.
Virginia Power noted that in the proposed rule, the definition of "important to safety" refers to"* .. (1) to provide reasonable assurance that high-level waste can be received, 9 handled, packaged, stored, emplaced, and retrieved without exceeding the requirements of [10 CFR] 60.lll(a) for Category 1 design basis events; or .... " Virginia Power recommended that this part of the definition should be revised to make it clear that the focus of important to safety is design basis events and not the normal operations that are described by the definition in the proposed rule.
The Commission disagrees with this comment. As explained in Item 13, the Commission intends that events occurring regularly or frequently during the course of normal operations are considered as Category 1 design basis events.
- 15. Definition of "Important to Safety" - Quality Assurance Issues.
Virginia Power and NEI stated that the definition of "important to safety" proposed in the proposed rule would apply 23
.full Quality Assurance (QA) requirements to almost every system and component of the repository, and that the latter definition does not establish a sraded QA system to properly distinguish systems that are "important to safety" and ensure that the full QA program is only applied to those systems.
The Commission disagrees with this comment. When identifying items "important to safety;" if it is determined that a particular structur~, system, or component is essential to maintaining doses below Part 20 limits during normal operations (or during any Category 1 design basis event), then.that structure, system, or component must be designated as_ "important to safety." The list of structures, systems, and components "important to safety," as well as the list of engineered barriers "important to waste isolation," are collectively referred to as the "Q-list" and are subject to the QA provisions of Part 60, Subpart G. The Commission supports a graded approach to meeting the QA provisions of Part 60. Such an approach is consistent with the NRC staff's "Technical Position on Items and Activities in the High-Level Waste Geologic Repository Program Subject to QA Requirements (NUREG-1318) ." The guidance given in that technical position (TP) is still applicable under the rule's changes. The TP describes a graded application of QA measures consistent with that applied to other facilities (e.g., nuclear power reactors) licensed by the Commission. In this regard, the application of QA program requirements to repository structures, *systems, and 24
I .
.components would generally be commensurate with their importance to safety.
- 16. Design Bases - Similarities between GROA Facility and other Facilities Licensed by NRC.
ECNP stated that it is wrong to liken design basis for a waste repository (or long-term storage) facility to design basis
- for an operating nuclear reactor or other contemporary nuclear facility because of the longevity of the hazard and uncertainties of future monitoring and control.
The Commission disagrees with this comment. The design bases provided in the rule are for operations at the GROA and not for postclosure performance. Because operations at the repository are expected to be similar to operations at other
- facilities licensed by the Commission (e.g., 10 CFR Part 72 facilities), the Commission believes that it is appropriate that their design bases be comparable.
- 17. The Phrase "At All Times".
ECNP recommended that the phrase "at all times" should be retained throughout Part 60.
The Commission disagrees with this comment. The phrase "at 25
all times" was originally included in the regulation to emphasize the need to design the GROA such that retrieval activities, if found necessary, would be conducted in accordance with Part 20.
The Commission continues to interpret the regulation in this manner but has removed the phrase "at all times" from §60.111 in the rule to clarify that the limits of Part 20 apply to Category 1 design basis events and. that the separate design bases of §60.136 apply for Category 2 design basis events. Further, the Commission recognizes that conformance to the regulations should not hinder any actions that *are necessary to protect public health and .safety, such as lifesaving or maintaining confinement of radioactive materials (May 21, 1991; 56 FR 23365).
The phrase "at all times" is ambiguous in this respect and was therefore removed.
ECNP recommended that NRC adopt an AHARA standard with respect to criteria for the design of the GROA. ECNP states that the purpose of such a standard would be to provide an extra measure of conservatism in the design. ECNP further states that, for an operating nuclear facility, regulatory changes over time that mandate tighter standards and reduced emissions can be 26
accommodated by means of backfitting, but this is not so readily accomplished at a disposal facility.
The Commission disagrees with this comment and considers that the requirements of Part 60, as amended in this rulemaking, are sufficient to ensure public health and safety. The Commission also considers that backfitting, if necessary, can be accomplished at a disposal facility.
Section-by-Section Analysis Section 60.2. Definitions.
The amendments involve 10 definitions needed in Part 60.
The term "preclosure controlled area" is new. It is essent:ally the same as the term "preclosure control area" proposed by DOE in its petition (PRM-60-3) and corresponds closely to the term "controlled area," as defined in 10 CFR 72.3.
The term "preclosure controlled area" is adopted because Part 60 already refers to a "controlled area" (which area has been committed to use as a geologic repository and from which incompatible activities*would be restricted following permanent closure). The function of the new term is to delimit an area over which the licensee exercises control of activities to meet regulatory requirements. Control includes the power to exclude 27
members of the public, if necessary. Because Part 60 (unlike Part 72) involves ongoing underground operations and timeframes of concern over centuries and millennia, language in the definition is included that, consistent with its function, limits the area to the surface and limits the duration to the period up to, and including, permanent closure.
The existing term "controlled area" is renamed "postclosure controlled area," to avoid any confusion or misunderstanding about this term in relation to its use in Parts 20 and 72.
However, no substantive change is intended for the "postclosure controlled area" because this is a change in*nomenclature only.
Consistent with this nomenclature change, the term "controlled area" is changed to "postclosure controlled area," where it appears in the definitions for "accessible environment,"
"disturbed zone," and "site."
The term "important to safety" is amended to address the issues previously discussed. The existing provision is unclear and fails to ensure proper levels of protection of public and worker health and safety for the broad range of conditions or events that might occur at a repository *site. This is an important term because it is the predicate for required design features as well as required quality assurance measures that provide defense-in-depth. The Commission is retaining the quantitative features of the existing.definition but is 28
specifying different numerical limits for each of the two categories (1 and 2) of design basis events. The structures, systems, and components "important to safety" are those necessary: (1) to provide reasonable assurance that the requirements of §60.lll(a) would be observed for Category 1 design basis events; or (2) to prevent or mitigate Category 2 design basis events that could result in doses equal to, or.
greater than, the values specified in [new] §60.136 to any e individual located on or beyond any point on the boundary of the preclosure controlled area.
Although the term "design bases" appears in existing Part 60, in §60.21(c) (2), it was not defined. As the previous discussion makes clear, "design bases" should be understood in relation to that range of events, including external natural or man-induced events, that is taken into account in the design,
- and, in particular, in relation to conditions that could result in radiological consequences beyond specified limits. The definition in Part 72 is inserted, without change, into the list of defined terms in §60.2.
The inclusion of a definition of "design basis events" serves two purposes. First, it identifies a set of events (referred to elsewhere as Category 1 design basis events) that must be taken into account in demonstrating compliance with the requirement to show, with reasonable assurance, that the 29
_provisions of Part 20 will be met. (This set of events is described as" ... those natural and human-induced events that are reasonably likely to occur regularly, *moderately frequently, or one or more times before permanent closure of the geologic repository operations area.") Second, it identifies an additional set of events (previously referred to as Category 2 design basis events) that must be taken into account in applying the Commission's defense-in-depth philosophy. (This set of events is described as those" ... other natural and human-induced -
events that are considered unlikely, but sufficiently credible to warrant consideration, taking into account the potential for significant radiological impacts on public health and safety.")
The Commission recognizes that the criterion of "sufficiently credible to warrant consideration" is inexact, leaving its application to a consideration of the particular site and design that are the subjects of a license application. Generally, the Commission would expect that such design basis events would include as broad a range of external phenomena as would be taken into account in defining the design basis for other regulated facilities, including nuclear reactors. The Commission would also expect that the analysis of a specific design basis event would require an analysis which includes an initiating event (e.g., an earthquake) and the associated combinations of repository sy*st:.em or component failures that can potentially lead to exposure of the public to radiation.
30
The definitions of "restricted area" and "unrestricted area" are amended to conform with the definitions in Part 20. The current definitions in Part 60 do not precisely conform to the current Part 20 because no change was made to these Part 60 definitions when Part 20 was revised.
The amendments of §60.2 adopted in this final rule differ from the amendments of §60.2 proposed in the proposed rule
- (March 22, 1995; 60 FR 15180) in the following respects: ( 1) the revised definitions of "restricted area" and "unrestricted area" were not proposed in the proposed rule; (2) in the definition of "important to safety," the phrases "features of the repository" and "nearest boundary" in the proposed rule were changed to "engineered features of the repository" and "any point on the boundary," respectively; (3) in the definition of 11 preclosure controlled area", the phrase "immediately surrounding the 9 geologic repository operations area" in the proposed rule was changed to "surrounding the GROA"; and (4) in the definition of "site", the phrase "location of the postclosure coI?-trolled area" was changed to "location of the preclosure controlled area, or of the postclosure controlled area, or both." The rationale for the revised definitions of restricted area" and "unrestricted area" is provided in the preceding paragraph. The rationale for the other changes is discussed under "Response to Public Comments on the Proposed Rule."
31
Section 60.8. Information collection regµirements:
0MB approval.
NRC is updating 10 CFR 60.8, "Information Collection Requirements: 0MB Approval," to reflect the fact that subsequent to the original issuance of Part 60, NRC requested, and obtained Office *of Management and Budget (0MB) approval for the Part 60 "Information Collection Requirements." Section 60.8 was to be corrected the first time other revisions were made.
The amendment of §60.8 adopted in this final rule differs from the amendment of §60.8 in the proposed rule (60 FR 15180) in that the term "Paperwork Reduction Act of 1980," in the proposed rule, has been changed to the term "Paperwork Reduction Act of 1995" in the final rule.
Section 60.21. Content of application.
The DOE petition suggested that provision for accident analysis might be accomplished by amendment of §60.111. The Commission, instead, is requiring an accident analysis as part of the content of the application section (i.e., §60.21). The language requires that the application address the potential dose, to any individual located on or beyond any point on the preclosure controlled area boundary, that is attributable to Category 2 design basis events. The procedure that is envisaged 32
_is that the applicant would address the Category 2 design basis events, singly, and demonstrate, by its analysis, that the doses to any individual located on or beyond any point on the preclosure controlled area boundary would be in accordance with the applicable requirements. The language serves the same purpose as the counterpart section of Part 72 (namely, 10 CFR 72.24[m]).
The final rule also reflects the position that the applicant must demonstrate that the requirements of Part 20 and the EPA standards will be met, assuming the occurrence of Category 1 design basis events. For this analysis, the applicant would calculate the sum of the doses, exposures, and releases from all Category 1 design basis events to ensure that these results do not exceed the limits specified in Part 20 and in the EPA standards.
The Commission also is eliminating certain terms in Part 60 that are undefined and may be subject to differing interpretations -- specifically, the terms "normal conditions,"
"anticipated operational occurrences," and "accidents." These terms are supplanted by the new term "design basis events."
Besides enhancing clarity of expression, the new language better reflects the articulated regulatory framework. Lastly, where the term "controlled area" appears in the language of this section, it is changed to "postclosure controlled area."
33
Section 60.43. License specification.
The term "controlled area" is changed to "postclosure controlled area."
Section 60.46. Particular activities requiring license amendment.
The term "controlled area" is changed to "postclosure controlled area."
Section 60.51. License amendment for permanent closure.
The term "controlled area" is changed to 11 postclosure controlled area. 11 Section 60.102. Concepts~
The term "controlled area" is changed to "postclosure controlled area."
Section 60.111. Performance of the geologic repository operations area through permanent closure.
The Commission is deleting the phrase "at all times" from 34
.the performance objective of §60.lll(a). This change clarifies that this requirement does not apply to radiation exposures, levels, and releases from Category 2 design basis events.
Section 60.121. Requirements for ownership and control of interests in land.
The term."controlled area" is changed to "postclosure e ' controlled area."
Section 60.122. Siting criteria.
The term "controlled area" is changed to "postclosure controlled area."
Section 60.130. Scope of design criteria for the geologic repository operations area.
The Commission is modifying the title of this section to the term "General Considerations" and is adding clarifying language, to the existing discussion, to indicate that §§60.131 through 60.134 specify the minimum criteria for the design of those structures, systems, and components important to safety, or important to waste isolation. These changes are necessary to provide consistency with the modified definition of "important to safety" (§60.2), as well as to clarify the purpose of these 35
criteria. These changes also provide consistency with the corresponding "minimum" design criteria, for an MRS, in Part 72.
Section 60.131. General design criteria for the geologic repository operations area.
Consistent with the modifications to §60.130, as described above, the Commission is deleting the reference to "Structures, systems, and components important to safety," in the title of
§60.13l(b), and re-numbering the current criteria in
§§60.13l(b) (1) through 60.13l{b) (10), as appropriate. This change eliminates the confusion in the existing rule related to the identification.of only the criteria in §60.13l(b) as "important to safety." It also resolves the present incongruity with §60 .131 (b) (7), "criticality control," regarding the reference to waste "isolation" (a.postclosure term) in the
. requirement.
The current rule employs the term "normal and accident conditions," or similar expression, in several places. However, the conditions that must be addressed under this language* are not well-defined. The Commission is remedying this situation by replacing current terminology with references to "design basis events," thereby ensuring that the design appropriately takes into account the consequences of all design basis events (i.e., as discussed in this document, Category 1 and 2 design 36
basis events). Accordingly, paragraphs (b) (5) (i), (b) (7), and (b) (8) are modified for this section. The Commission also is revising the language in §60.131(b) (1), which refers to "anticipated" natural phenomena and environmental conditions, so as to encompass all design basis events. The "necessary safety functions" that must be accommodated in the design, pursuant to that paragraph, include whatever is necessary to meet the quantitative limits set out in the Commission's rules (i.e., in
- §60.lll(a) and §60.136).
As discussed under "Public Comments on the Proposed Rule,"
' the Commission considers the applicability of the criticality
, control requirements in §60.131(h) to be clear with respect to preclosure considerations. The Commission also believes that
, uncertainty remains with respect to the applicability of the criticality control requirements to the postclosure period. The 9 Commission intends to address the remaining uncertainty in a future rulemaking to make the NRC requirements consistent with the revised EPA standards that are currently under development, as mandated by the Energy Policy Act of 1992.
Section 60.132. Additional design criteria for surface facilities in the geologic repository operations area.
Section 60.132(c) (1) requires that the surface facilities must be" ... designed to control the release of radioactive 37
materials in effluents during normal operations so as to meet the performance objectives of §60.lll(a) ." The design should ordinarily be sufficient to provide reasonable assurance of meeting Part 2.0 not only during normal operations, but even for events that are likely to occur moderately frequently or one or more times before permanent closure of the geologic repository (i.e., all Category 1 design basis events). Deleting the phrase "during normal operations," broadens the scope of this provision to reflect the Commission's intent more accurately. e The amendment of §60.132 adopted in this final rule differs from the amendment of §60.132 in the proposed rule in that the phrase "in effluents" iri the proposed rule was changed to "in effluents during Category*1 design basis events" in the final rule. The rationale for this change was discussed in the "Response to Public Comments on the Proposed Rule."
Section 60.133. Additional design criteria for the underground facility.
As in the case of the changes to 10 CFR 60.131, a reference to design basis events is substituted for the less precise "normal operations.and ... accident conditions."
Section 60.136. Preclosure controlled area.
38
The final rule adopts the petitioner's concept of a preclosure control area under the name "preclosure controlled area." The term delimits an area over which the licensee exercises control of activities to meet regulatory requirements.
, Control would include the ability to exclude members of the public, if necessary. The zone, and related dose limits, would also be used to analyze and identify structures, systems, and '
components that are important to safety under unusual conditions
- 'that have heretofore been characterized as Category 2 design basis events - credible, yet not likely to occur during the period of operations. The issue that is presented concerns the dose limits to ensure that the consequences of any events which
' occur present no unreasonable risk to the health and safety of
' the public. (Releases resulting from Category 1 design basis events would not be permitted to cause doses exceeding the limit.s of Part 20.) The Commission adopts the basic provisions of e Part 72 - namely, a 0.05 Sv (5 rem) dose limit, on or beyond the preclosure controlled area boundary - as modified to reflect the Part 20 system of dose limits (see §20.120l[a]). In addition to providing for separate dose limits for individual organs and tissue, the lens of the eye, and the skin, the use of "total effective dose equivalent" (TEDE) in Part 20 explicitly accounts for exposures via the ingestion and inhalation dose pathways.
Modification of the 0.05 Sv (5 rem) dose limit, to reflect the Part 20 system of dose limits, results in a family of dose 39
.limits: a TEDE of 0.05 Sv (5 rem); or the sum of the deep-dose equivalent* and the committed dose equivalent to any individual organ or tissue (other than the lens of the eye) of 0.5 Sv (SO rem); an eye dose equivalent of 0.15 Sv (15 rem); and a shallow dose equivalent, to skin, of 0.5 Sv (50 rem) . 2 The eye and skin dose limits are adequate to ensure that no observable effects* (e.g., induction of cataracts in the lens of the eye) will occur as a result of any accidental radiation exposure. In implementing this provision, dose calculations $hould be made solely with reference to the consequence of the specific Category 2 design basis event, not cumulatively with other design basis events. To clarify this matter further, the analysis of a specific Category 2 design basis event would require an analysis which includes an initiating event (e.g., an earthquake) and the associated combinations of repository system or component failures that can potentially lead to exposure of the public to radiation. An example design basis event is a postulated earthquake (the initiating event) which results in: (1) the failure of a crane lifting a spent fuel waste package inside a waste handling building, (2) damage to the building ventilation filtration system, (3) the drop and b~each of the waste package, (4) damage to the spent fuel, (5) partitioning of a fraction of the radionuclide inventory to the build~ng atmosphere, (6) release of some radioactive material through the damaged 2
Radiation exposure terminology is as used in Part 20 (56. FR 23360; May 21, 1991).
40
ventilation filtration system, and (7) public exposure to the released radioactive material. It should be npted that it is not necessary to assume multiple failures of safety-related systems unless these multiple failures are credible consequences of the initiating event. An analysis of a specific event for a real repository would be dependent on the particular features of the 1 facility design and related operating procedures. In general, credit for the proper functioning of repository structures, e systems, and components in an analysis would be commensurate with
, the merits of the design. In the example cited above, a waste package designated "important to safety" would not necessarily be assumed to breach in a drop event if the maximum hypothetical drop falls within the design parameters of the waste package to withstand such an event. Similarly, repository ventilation filtration systems would be analyzed for their capability to withstand natural phenomena (e.g., earthquakes) and detect, isolate, or filter radioactive material in ventilat~on flow.
The only other noteworthy deviation from Part 72 is to refer in §60.136 to doses attributable to any "Category 2 design basis event" whereas the corresponding section (i.e., 10 CFR 72 .106) in Part 72 refers to doses attributable to any "design basis accident." The term "design basis event" is used because it is a defined term in Part 60. The change in terminology is not intended to be one of substance as Category 2 design basis events would generally be considered as accidents.
41
The 0.05 Sv (5 rem) dose limit is being adopted by the Commission as the appropriate design basis for protection of public health and safety from Category 2 *design basis events at a GROA and will harmonize Part 60 with Part 72. In this regard, the Commission notes that Part 72 applies to those facilities (MRS installations) most similar to the surface facilities of a repository and for which the kinds of design basis events are also expected to be similar. Further, the dose limit is consistent with dose values (0.06 Sv [6 rem] to the whole body) established as guidance for both fuel-handling accidents and spent-fuel cask-drop accidents at nuclear power plants. 3 Moreover, the dose limit is consistent with the accident-dose value (0.05 Sv [5 rem] effective dose equivalent) proposed by DOE in its PRM.
However, while* _consistency between the proposed O. 05 Sv (5 rem) dose limit for Part* .60 and other Commission rules or.
guidance documents is important, consistency alone does not necessarily ensure tha:t there would b_e no unreasonable risk to the health and safety of the. public associated with the proposed limit. As such, a perspective is provided on the risks associated with an operational repository and the appropriateness of the proposed 0.05 Sv (5 rem) dose limit as the design basis for protection of public health and safety from Category 2 design 3
NUREG-0800, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants," June 1987.
42
basis events.
Based on estimates provided by the National Council on Radiation Protection and Measurements 4 , the lifetime risk to individuals in the general population is 0.05 fatal cancers per Sv of exposure. Therefore, the lifetime risk of fatal cancer from an assumed 0.05 Sv (5 rem) exposure resulting from a postulated Category 2 design basis event is 0.0025 (i.e., 2.5 x 10- 3 ) per individual exposed. While this assessment provides perspective on the risk associated with a hypothetical exposure of a 0.05 Sv (5 rem) dose, it does not provide perspective on the estimated actual risk associated with the spectrum of possible Category 2 design basis events at a repository during its operational lifetime (estimated to be about 100 years).
Perspective on actual risk must include consideration of the frequencies (i.e., probabilities) of occurrence of these events, as well as their consequences, as "risk" is defined as "the probability of an event times its consequences." With respect to the range of probabilities of Category 2 design basis events, the upper bound is roughly 1 x 10- 2 per year (i.e., events with probabilities of occurrence greater than 1 x 10- 2 per year would generally be considered to be Category 1 events). Accordingly, assuming event consequences equivalent to the 0.05 Sv (5 rem) 4 National Council on Radiation Protection and Measurements, "Risk Estimates for Radiation Protection," NCRP Report No. 115, December 31, 1993.
43
dose limit for Part 60, the hypothetical upper bound on individual risk is 2.5 x 10-s fatal cancers per year. To put this risk in perspective, the International Commission on Radiological Protection 5 notes that, based on a review of information related to risks regularly accepted in everyday life for stochastic phenomena, a fatal cancer risk in the range of 1 x 10- 6 to 1 x 10-s per year from exposure to radiation would likely be acceptable to individual members of the public. Thus, while the risk associated with the consequences of a repository event at the dose limit and upper bound probability of occurrence exceeds this range by a small factor, and is at a level that the Commission considers safe for occupational exposures, the Commission believes this result significantly overestimates the actual risk of an operating repository. Similarly, the Commission considers that the lower bound of Category 2 design basis events is on the order of 1 x 10- 6 per year (i.e. , events with probabilities of occurrence less than 1 x 10- 6 per year ,
would generally be screened from further consideration due to their negligible contribution to overall ri.sk) . In the proposed rule* (March 22, 1995; 60 FR 15180) , the Commission had considered a probability of occurrence of 1 x 10- 9 per year as an appropriate lower bound. However,. upon further analysis as discussed below, the Commission considers that a lower bound of 1 x 10- 9 per year is too low and unjustified, and that a lower 5
Recommendations of the International Commission on Radiological Protection.* ICRP Publication 26, January 1977.
44
, bound of 1 x 10- 6 per year is appropriate. Screening out events with probabilities of less than 1 x 10- 6 is expected to provide conservative estimates of risk. A higher screening criterion could probably be justified given the magnitude of the consequences and risks from this facility, but this criterion is not expected to cause an excessive analytical burden for demonstating compliance with §60.136, consistent with the Commission's guidance on the application of probability risk
- , assessment methods in licensing. It is important to note that the arguments advanced for this screening criterion apply solely to the period of repository operations before permanent closure.
Assuming bounding repository event consequences of roughly 0.2 Sv (20 rem), a lifetime risk to individuals in the general population of 0.05 fatal cancers per Sv of exposure, and a lower
- bound of 1 x 10- 6 per year for the probability of occurrence of Category 2 design basis events, the estimated risk of cancer fatality from these low probability events would be 1 x 10- 0 per year. Events which result in risks at or below this level do not contribute significantly to repository risk to an individual and, as such, can be neglected in the overall risk assessment.
Perspective on actual repository risk can be obtained by developing an understanding of the spectrum of potential 45
Category 2 design basis events and estimating the consequences of these sequences; as well as their probabilities of occurrence.
In this regard, the Commission recognizes that ~there is no high-level waste repository operating experience, and that only conceptual designs have been developed for these facilities.
Nonetheless, some perspective can be gained from the preliminary risk as*sessment by DOE 6 of a conceptual design_ for a repository at Yucca Mountain, Nevada, as well as from consideration of risk assessments of selected U.S. nuclear power plants. 7 Consistent with risk assessments for nuclear power plants, the spectrum of possible repository design basis events includes both internally and externally initiated events. Internally initiated events would include waste transporter collisions, crane failures or other types of fuel assembly, waste package or cask drop events, building or facility exhaust filter fires, and exhaust filter bypass or failure. Externally initiated events would include those resulting from earthquakes, tornados, and flooding. Regardless of the type or nature of the initiating event, the Commission believes that, for several reasons, both the variety of credible events and the resulting potential consequences to members of the public will be somewhat limited at 6
U.S. Department of Energy, "Site Characterization Plan, Yucca Mountain Site, Nevada Research and Development Area, Nevada,"
DOE/RW-0199, December-1988.
7
- NUREG-1150. "Severe Accident Risks: An Assessment for Five U.S. Nuclear Power Plants,". December 1990.
46
.repository facilities. First, in comparison with a nuclear power plant, an operating repository is a relatively simple facility in which the primary activities are waste receipt, handling, storage, and emplacement. A repository does not require the variety and complexity of active systems necessary to support an operating nuclear power plant. Further, the conditions are not present at a repository to generate a radioactive source term of a magnitude that, however unlikely, is potentially capable at a 9 nuclear power plant (e.g., from a postulated loss of coolant event). As such, the estimated consequences resulting from limited source term generation at a repository would be correspondingly limited. This conclusion is consistent with the results of the aforementioned preliminary risk assessment by DOE of a conceptual repository design at Yucca Mountain, Nevada. In that assessment, DOE considered 149 events for a variety of internally and externally initiated events. Of the 149 events, e only 7 resulted in offsite doses in excess of 0.005 Sv (0.5 rem) to the critical organs of a maximally exposed individual and also had associated probabilities of occurrence greater than 1 x 10- 9 per year. The highest estimated offsite dose from the DOE risk assessment was 0.021 Sv (2.1 rem) with an associated probability of occurrence of 5 x 10- 1 per year.
The dose estimates of the DOE risk assessment are only reflective of a conceptual design for a repository at Yucca Mountain, Nevada. Nonetheless, the Commission believes they 47
.provide perspective on the magnitude of the estimated consequences to members of the public from postulated Category 2 design basis events, and that variations in repository design or site selection would not likely vary these estimates by more than an order of magnitude. The results of the DOE risk assessment also provide some perspective on the estimated probabilities of occurrence of the postulated repository design basis events and, as such, perspective on actual risk.from an operating repository.
In general, the Commission would expect the potential higher consequence events to have correspondingly lower probabilities of occurrence. This expectation is consistent with the results of the DOE risk assessment as the estimated probabilities of occurrence for the seven events which resulted in offsite doses in excess of 0. 005 Sv ( 0. 5 rem) vary from 1 x 10- 9 to 5 x 10- 6 per year. The corollary to this is the expectation that higher frequency events would have correspondingly lower offsite consequences, and perspective on actual risk from an operating repository necessitates consideration of these events, as well as lower frequency events. Review of the DOE risk assessment indicates that some higher frequency, but lower consequence, events are just as important to actual risk as the lower frequency, , but higher consequence, events. With respect to actual risk from the broad spectrum of all events considered in the DOE risk assessment, the estimated actual risk of an operating repository is roughly two to three orders of magnitude 48
-lower than the range of fatal cancer risks that would likely be acceptable to members of the public (i.e., a fatal cancer risk of 1 x 10- 6 to 1 x 10-s per year as noted in ICRP Publication 26).
With respect to the appropriateness of the proposed 0.05 Sv (5 rem) dose limit for Part 60 as the design basis for protection of public health and safety from Category 2 design basis events, the DOE risk assessment indicates the potential for events with 9 offsite consequences on the order of several hundredths to several tenths of Sv (several rem to several tens of rem),
depending on design and siting factors. The event consequences in this range, coupled with the estimated event probabilities of occurrence, result in estimated risks that would likely be acceptable to members of the public'. However, given the lack of repository design, siting and operating experience and the supporting data base for probabilistic risk assessment,. the
- Commission believes there is considerable uncertain~y in the estimates of both the consequences and the probabilities of occurrence of postulated Category 2 design basis events. As such, the Commission believes that establishing a dose limit in Part 60 to the 0.05 Sv (5 rem) value would provide an adequate margin of safety and an appropriate design basis for protection of members of the public from unlikely, but credible events.
Further, the Commission believes that a single dose limit is appropriate for the broad range of possible event frequencies, given the limited potential for offsite consequences at 49
.repository facilities.
Lastly, the amendments of §60.136 adopted in this final rule differ slightly from the amendments of §60.136 proposed in the proposed rule (60 FR 15180) in that the phrase "on or beyond the nearest boundary" in the proposed rule was changed to "on or beyond *any point on the boundary" in the final rule and the phrase "may not exceed" in the proposed rule was changed to "shall not exceed" in the final rule. The rationale for the latter change is to improve clarity and the rationale for the former change was discussed earlier in the "Response to Public Comments on the Proposed Rule."
Section 60.183. Criminal penalties.
In the proposed rule, a conforming change was made to this section to include §60.136 (pertaining to the preclosure controlled area) among the regulations that are not issued under Sections 161b, 161i, or 1610 of the Atomic Energy Act, for purposes of Section 223 of the Act. On reconsideration, the Commission has decided not to revise this section (i.e., criminal penalties are authorized for violations of §60.136).
Small Business Regulatory Enforcement Fairness Act In accordance with the Small Business Regulatory Enforcement 50
.Fairness Act of 1996, the NRC has determined that this action is not a major rule and has verified this determination with the Office of Information and.Regulatory Affairs of 0MB.
Environmental Impact: Categorical Exclusion The NRC has determined that this regulation is the type of action described in 10 CFR 51.22 (c) (2), pertaining to the 9 promulgation of technical requirements and criteria that the Commission will apply in approving or disapproving applications under Part 60. Therefore, neither an environmental impact statement nor an environmental assessment has been prepared for this final rule.
Paperwork Reduction Act Statement This final rule does not contain a new or amend8d information collection requirement subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501, et seg.). Existing requirements were approved by 0MB, approval number 3150-0127.
Public Protection Notification The NRC may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid 0MB control number.
51
Regulatory Analysis The Commission has prepared a regulatory analysis on this final rule. The analysis examines the costs and benefits of the alternatives considered by the Commission. The analysis is available for inspection in the NRC Public Document Room, 2120 L Street NW (Lower Level), Washington, DC. Single copies of the analysis may be obtained from Dr. Richard A. Weller, U.S.
Nuclear Regulatory Commission, Office of Nuclear Material Safety and Safeguards, Division of Waste Management, Washington, DC 20555, Telephone (301) 415-7287.
Regulatory Flexibility Certification As required by the Regulatory Flexibility Act of 1980, 5 U.S.C. 605(b), the Commission certifies that this rule will not have a significant economic impact on a substantial. number of small entities. The only entity subject to regulation under this rule is DOE.
Backfit Analysis The NRC has determined that the backfit rule, 10 CFR 50.109, does not apply *-to this final rule and, therefore, that a backfit analysis is not required for this final rule, because these amendments do not involve any provisions that would impose 52
backfits as defined in 10 CFR 50.109(a) (1).
List of Subjects in 10 CFR Part 60 Criminal penalties, High-level waste, Nuclear power plants and reactors, Nuclear materials, Reporting and record-keeping requirements, and Waste treatment and disposal.
For the reasons set out in the preamble and under the authority of the Atomic Energy Act of 1954, as amended; the Energy Reorganization Act of 1974, as amended; the Nuclear Waste Policy Act of 1982, as amended; and 5 U.S.C. 552 and 553, the NRC is adopting the following amendments to Part 60.
53
PART 60 - DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES
- 1. The authority citation for Part 60 is amended to read as follows:
Authority: Secs. 51, 53, 62, 63., 65, 81, 161, 182, 183, 68 Stat. 929, 930, 932, 933, 935, 948, 953, 954, as amended (42 u.s.c. 2071, 2073, 2092, 2093, 2095, 2111, 2201, 2232, 2233);
secs. 202, 206, 88 Stat. 1244, 1246 (42 U.S.C. 5842, 5846);
secs. 10 and 14, Pub. L.95-601, 92 Stat. 2951 (42 u.s.c. 2021a and 5851); sec. 102, Pub. L.91-190, 83 Stat. 853 (42 U.S.C.
4332); secs. 114, 121, Pub. L.97-425, 96 Stat. 2213g, 2228, as amended (42 U.S.C. 10134, 10141), and Pub. L. 102-486, sec. 2902, 106 Stat. 3123 (42 U.S.C. 5851).
- 2. Section 60.2 is amended by adding definitions of "Design bases," "Design basis events," and "Preclosure controlled area,"
revising the definitions of "Accessible environment," "Disturbed zone," "Important to safety," and "Site," revising the name of the defined term "Controlled area" to "Postclosure controlled area" and presenting this renamed term without change for the convenience of the user, and alphabetizing the definitions to read as follows:
54
.§60.2. Definitions.
Accessible environment means:
(1) The atmosphere; (2) The land surface; (3) Surface water; (4) Oceans; and (5) The portion of the lithosphere that is outside the 9 postclosure controlled area.
Design bases means that information that identifies the specific functions to be performed by a structure, system, or component of a facility and the specific values or ranges of values chosen for controlling parameters as reference bounds for design. These values may be restraints derived from generally accepted "state-of-the-art" practices for achieving functional goals or requirements derived from analysis (based on calculation or experiments) of the effects of a postulated event under which a structure, system, or component must meet its functional goals.
The values for controlling parameters for external events include:
(1) Estimates of severe natural events to be used for deriving design bases that will be based on consideration of historical data on the associated parameters, physical data, or analysis of upper limits of the physical processes involved; and 55
(2) Estimates of severe external man-induced events, to be used for deriving design bases, that will be based on analysis of human activity in the region, taking into account the site characteristics and the risks associated with the event.
Design basis events means:
(1) (i) Those natural and human-induced. events that are reasonably likely to occur regularly, moderately frequently, or one or more times before permanent closure of the geologic repository operations area; and (ii) Other natural and man-induced events that are considered unlikely, but sufficiently credible to warrant consideration, taking into account the potential for significant radiological impacts on public health and safety.
(2) The events described in paragraph (1) (i) of this definition are referred to as "Category 1" design basis events.
The events described in paragraph (1) (ii) of this definition ari referred to as "Category 2" design basis events.
Disturbed zone means that portion of the postclosure controlled area, the physical or chemical properties of which have changed as a result of underground facility construction or as a result of heat generated by the emplaced radioactive wastes, such that the resultant change of properties may have a significant effect on the performance of the geologic repository.
56
Important to safety. with reference to structures, systems, and components, means those engineered features of the repository whose function is:
(1) To provide reasonable assurance that high-level waste can be received, handled, packaged, stored, emplaced, and retrieved without exceeding the requirements of §60.lll(a) for e* Category 1 design basis events; or (2) To prevent or mitigate Category 2 design basis events that could result in doses equal to or greater than the values specified in §60.136 to any individual located on or beyond any point on the boundary of the prec~osure controlled area.
Postclosure controlled area means a surface location, to be
- marked by suitable monuments, extending horizontally no more than 10 kilometers in any direction from the outer boundary of the underground facility, and the underlying subsurface, which area has been committed to use as a geologic repository and from which incompatible activities would be restricted following permanent closure.
Preclosure controlled area means that surface area surrounding the geologic repository operations area for which.the licensee exercises authority over its use, in accordance with the 57
provisions of this part, until permanent closure has been completed.
Restricted area means an area, access to which is limited by the licensee for the purpose of protecting individuals against undue risks from exposure to radiation and radioactive materials.
Restricted area does not include areas used as residential quarters, but separate rooms in a residential building may be set aside as a restricted area.
Site means the location of the preclosure controlled area, or of-the postclosute controlled area, or both.
Unrestricted area means an area, access to which is neither limited nor controlled by the licensee.
- 3. Section 60.8 is revised to read as follows:
§60.8 Information Collection Requirements:
- Approval.
{a) The Nuclear Regulatory-Commission has submitted the information collection requirements of gerieral applicability contained in this part to the Office of Management and Budget for approval as required by the*Paperwork Reduction Act of 1995 (44 U.S.C. 3501, et seg.). The Office of Management and Budget 58
.has approved the information collection requirements contained in this part under control number 3150-0127.
(b) The approved information collection requirements contained in this part appear in §§60.62, 60.63, and 60.65.
- 4. In §60.21, paragraphs (c) (1) (i), (c) (1) (ii) (B), (c) (3),
and (c) (8) are revised to read as follows:
§60.21. Content of application.
( c) * * *
( 1) * * *
(i) The description of the site shall also include the following information regarding subsurface conditions. This description shall, in all cases, include this information with respect to the postclosure controlled area. In addition, where subsurface conditions outside the postclosure controlled area may affect isolation within the postclosure controlled area, the description shall include information with respect to subsurface conditions outside the postclosure controlled area to the extent the information is relevant and material. The detailed information referred to in this paragraph shall include:
(A) The orientation, distribution, aperture in-filling and origin of fractures, discontinuities, and heterogeneities; 59
(B) The presence and characteristics of other potential pathways such as solution features, breccia pipes, or other potentially permeable features; (C) The geomechanical properties *and conditions, including pore pressure and ambient stress conditions; (D) The hydrogeologic properties and conditions; (E) The geochemical 'properties; and (F) The anticipated response of the geomechanical, hydrogeologic, and geochemical systems to the maximum design thermal loading, given the pattern of fractures and other discontinuities and the heat transfer properties of the rock mass and groundwater.
(ii) * * *
(B) Analyses to determine the degree to which each of the favorable and potentially adverse conditions, if present, has been characterized, and the extent to which it contributes to or detracts from isolation. For the purpose of determining the presence of the-potentially adverse conditions, investigations shall extend from the surface to a depth sufficient to determine*
critical pathways for radionuclide migration from the underground facility to the accessible environment. Potentially adverse 60
conditions shall be investigated outside of the postclosure
'controlled area if they affect isolation within the postclosure controlled area.
(3) A description and analysis of the design and 1
performance requirements for structures, systems, and components of the geologic repository that are important to safety. The analysis must include a demonstration that --
- (i) The requirements of §60.lll(a) will be met, assuming occurrence of Category 1 design basis events; and (ii) The requirements of §60.136 will be met, assuming occurrence of Category 2 design basis events.
(8) A description of the controls that the applicant will apply to restrict access and to regulate land use at the site and adjacent areas, including a conceptual design of monuments which
- would be used to identify the postclosure controlled area after permanent closure.
§60. 43 [Amended]
- 5. In §60 .43 (b) (5), the term "controlled area" is revised to read "postclosure controlled area."
§60. 46 [Amended]
61
- 6. In §60.46(a) (3), the term "controlled area" is revised to read "postclosure controlled area."
§60. 51 [Amended]
- 7. In §60. 51 (a) (2) (i) and (a) (2) (ii), the term "controlled area" i~ revised to read "postclosure controlled area."
§60.102 [Amended]
- 8. In §60.102(c), the term "controlled area" is revised to read "postclosure controlled area."
- 9. In §60.111, paragraph (a) is revised to read as follows:
§60.111. Performance of the geologic repository operations area through permanent closure.
(a) Protection against radiation exposures and releases of radioactive material. The geologic repository operations area shall be designed so that until permanent closure has been completed, radiation exposures and radiation levels, and releases of radioactive materials to unrestricted areas, will be maintained within the limits specified in Part 20 of this chapter and such generally applicable environmental standards for radioactivity as may have been established by Environmental 62
Protection Agency.
§60.121 [Amended]
- 10. In §60.121(a) and (b), the term "controlled area" is revised to read "postclosure controlled area."
§60.122 [Amended]
- 11. In §60 .122 (b) (6) and (c), the term "controlled area" is revised to read "postclosure controlled area."
- 12. Section 60.130 is revised to read as follows:
§60.130 General considerations.
Pursuant to the provisions of §60.21(c) (2) (i), an application to receive, possess, store, and dispose of high-level radioactive waste in the geologic repository operations area must include the principal design criteria for a proposed facility.
The principal design criteria establish the necessary design, fabrication, construction, testing, maintenance, and performance requirements for structures, systems, and components important to safety and/or important to waste isolation. Sections 60.131 through 60.134 specify minimum requirements for the principal design criteria for the geologic repository operations area.
63
.These design criteria are not intended to be exhaustive.
However, omissions in §§60.131 through 60.134 do not relieve DOE from any obligation to provide such features in a specific facility needed to achieve the performance objectives.
- 13. In §60.131, paragraph (b) is revised, and paragraphs (c) through (k) are added to read as follows:
§60.131. General design criteria for the geologic repository operations area.
(b) Protection against design basis events. The structures, systems, and components important to safety shall be designed so that they will. perform their necessary safety functions, assuming occurrence of design basis events.
(c) Protection against dynamic effects of equipment failure and similar events. The structures, systems, and components important to safety shall be designed to withstand dynamic effects such as missile impacts, that could result from equipment failure, and similar events and conditions that could lead to loss of their safety functions.
(d) Protection against fires* and explosions.
(1) The structures, systems, and components important to 64
.safety shall be designed to perform their safety functions during and after credible fires or explosions in the geologic repository operations area.
(2) To the extent practicable, the geologic repository operations area shall be designed to incorporate the use of noncombustible and heat resistant materials.
(3) The geologic repository operations area shall be designed to include explosion and fire detection alarm systems and appropriate suppression systems with sufficient capacity and capability to reduce the adverse effects of fires and explosions on structures, systems, and components important to safety.
(4) The geologic repository operations area shall be designed to include means to protect systems, structures, and components important to safety against the adverse =ffects of either the operation or failure of the fire suppression systems.
(e) Emergency capability.
(1) The structures, systems, and components important to safety shall be designed to maintain control of radioactive waste and radioactive effluents, and permit prompt termination of operations and evacuation of personnel during an emergency.
65
(2) The geologic repository operations area shall be designed to include onsite facilities and services that ensure a safe and timely response to emergency conditions and that facilitate the use of available offsite services (such as fire, police, medical, and ambulance service) that may aid in recovery from emergencies.
(f) Utility services.
(1) Each utility service system that is important to safety shall be designed so that essential safety functions can be performed, assuming occurrence of the design basis events.
(2) The utility services important to safety shall include redundant systems to the extent necessary to maintain, with adequate capacity, the ability to perform their safety functions.
(3) Provisions shall be made so that, if there is a loss of the primary electric power source or circuit, reliable and timely emergency power can be provided to instruments, utility service systems, and operating systems, including alarm systems, important to safety.
(g) Inspection, testing, and maintenance. The structures, systems, and components important to safety shall be designed to permit periodic inspection, testing, and maintenance, as 66
necessary, to ensure their continued functioning and readiness.
(h) Criticality control. All systems for processing,
' transporting, handling, storage, retrieval, emplacement, and isolation of radioactive waste shall be designed to ensure that nuclear criticality is not possible unless at least two unlikely, independent, and concurrent or sequential changes have occurred in the conditions essential to nuclear criticality safety. Each
- system must be designed for criticality safety assuming occurrence of design basis events. The calculated effective multiplication factor (keff) must be sufficiently below unity to show at least a 5 percent margin, after allowance for the bias in the method of calculation and the uncertainty in the experiments used to validate the method of calculation.
(i) Instrumentation and control systems. The design shall
- include provisions for instrumentation and control systems to monitor and control the behavior of systems important to safety, assuming occurrence of design basis events.
(j) Compliance with mining regulations. To the extent that DOE is not subject to the Federal Mine Safety and Health Act of 1977, as to the construction and operation of the geologic repository operations area, the design of the geologic repository operations area shall nevertheless include provisions for worker protection necessary to provide reasonable assurance that all 67
.structures, systems, and components important to safety can perform their intended functions. Any deviation from relevant design requirements in 30 CFR, Chapter I, Subchapters D, E, and N will give rise to a rebuttable presumption that.this requirement has not been met.
(k) Shaft conveyances used in radioactive waste handling.
(1) Hoists important to safety shall be designed to preclude cage free fall.
(2) Hoists important to safety shall be designed with a reliable cage location system.
(3) Loading and unloading systems for hoists important to safety shall be designed with a reliable system of interlocks that will*fail safely upon malfunction.
(4) Hoists important to safety shall be designed to include two independent indicators to indicate when waste packages are in place and ready for transfer.
- 14. In §60.132, paragraph (c) (1) is revised to read as follows:
§60.132. Additional design criteria for surface facilities in 68
.the geologic repository operations area.
(c) Radiation control and monitoring - (1) Effluent control.
The surface facilities shall be designed to control the release of radioactive materials in effluents during Category 1 design basis events so as to meet the performance objectives of
§60 .111 (a) .
- 15. In §60.133, the introductory texts of paragraph (g) and
, paragraph (g) (2) are revised to read as follows:
§60.133 Additional design criteria for the underground facility.
(g) Underground facility ventilation. The ventilation system shall be designed to:
(2) Assure the ability to perform essential safety functions assuming occurrence of design basis events.
- 16. A new undesignated center heading and §60.136 are added to read as follows:
Preclosure Controlled Area
§60.136 Preclosure controlled area.
69
(a) A preclosure controlled area must be established for the geologic repository operations area.
(b) The-geologic repository operations area shall be designed so that, for Category 2 design basis events, no individual located on or beyond any point on the boundary of the preclosure controlled area will receive the more limiting of a total effective dose equivalent of 0.05 Sv (5 rem), or the sum of the deep-dose equivalent and the committed dose equivalent to any individual organ or tissue (other than the lens of the eye) of 0.5 Sv (50 rem). The eye dose equivalent shall not exceed 0.15 Sv (15 rem), and the shallow dose equivalent to skin shall riot exceed 0.5 Sv (50 rem). The minimum distance from the surface. facilities in the geologic repository operations area to the boundary of the preclosure controlled area must be at least 100 meters.
70
(c) The preclosure controlled area may be traversed by a highway, railroad, or waterway, so long as appropriate and
, effective arrangements are made to control traffic and to protect public health and safety.
'] ,,...rt_
Dated in Rockville, Maryland, this ":::>iJ -day of November, 1996.
For the Nuclear Regulatory Commission.
John ~? ecretary of the Commission.
71
DOCKET NUMBER [7590-01-P]
PETITION RULE PRM (oo -:5 (55F'f\a<a'1'1f).
NUCLEAR REGULATORY COMMISSION 10 CFR PART 60
~95 MftR 17 A9 :54
[Docket No. PRM-60-3]
OFFICE Of ::'.::.CRE Tt\RY DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC ~pfd~T~R'1.~i-u u f\ r-*'\ , 1 *--"' i i RViCE AGENCY: U.S. Nuclear Regulatory Commission ACTION: Partial .. Grant/Partial Denial of Petition for Rulemaking
.\
SUMMARY
- In a petition for rulemaking (PRM-60-3) submitted by L_.e U.S. Department of Energy (DOE), the U.S. Nuclear Regulatory Commission was requested to establish specific dose criteria for design basis accidents at a high-level radioactive waste repository. NRC hereby grants in part, and denies in part, the specific proposals of the petitioner.
ADDRESSES: Copies of the petition for rulemaking, the public comments received, and NRC's letter to the petitioner are available for public inspectio11 or copying, for a fee, in U,e NRC Public Document Room, 2120 L Street, NW (Lower Level), Washington, DC 20555.
FOR FURTHER INFORMATIO.N CONTACT: Dr. Richard Weller, Office of Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, Washington, DC 20555, telephone (301) 415-7287.
~~- ~\a~\qs
(~OF'R \5\C\CJ
I I SUPPLEMENTARY INFORMATION: i DOE submitted a petition for rulemaking on April 19, 1990. On July 13, 1990, (55 FR 28771) NRC published a notice. of receipt of the petition for rulemaking. The comment period expired on October 11, 1990. The petition requested that the Commission amend 10 CFR Part 60 to prescribe certain
- numerical accident-dose criteria to be applied at the boundary of a "preclosure control area."
Under DOE's proposal, the definition of "important to safety," in 10 CFR 60.2, would be changed to apply a reference dose limit at the preclosure-control-area boundary, instead of the present unrestricted-area boundary; further, the definition would be amended to add a statement "All engineered safety features shall be includeq within the meaning of the term
'important to safety.'" The petition also proposed that performance objectives of 10 CFR 60.111 would be revised to incorporate an expJicit accident dose limit, at the preclosure control area boundary, of 0.05-Sv (5-rem) effective dose equivalent, or 0.5-Sv (50-rem) committed dose equivalent. DOE indicated its intention that this limit would apply to direct irradiation and inhalation pathways, alone, and not to ingestion of contaminated foodstuffs. The phrase "at all times" would be deleted from 10 CFR 60.lll(a), to clarify that the performance objective for the period of operations does not apply to exposure from accidents. Finally, the petition proposed adding new definitions, to 10 CFR 60.2, for the terms "preclosure control area," "committed dose equivalent," "committed effective dose equivalent," and "effective dose equivalent," to support the application of the accidert dose criteria described above.
For a fuller statement of the petition for rulemaking, see the Federal Register notice cited above.
In response to NRC's publication of notice of receipt of the petition.
comments were received from: DOE: Edison Electric Institute and the Utility
' Nuclear Waste and Transportation Program (EEI/UWASTE): Intertech Consultants.
, on behalf of Lincoln County, Nevada. and the City of Caliente. Nevada: and an anonymous "Concerned U.S. Citizen." The Commission. having now considered the petition and comments. grants the petition in part and denies the petition in
- part. and to that end. the Commission is publishing. concurrently with this notice. a notice of proposed rulemaking.
Under the proposed rule. accident-dose criteria would be applied at the boundary of a newly defined "preclosure controlled area," as recommended by DOE. Further. in response to the petition. the term "important to safety" would be redefined. though not in the form suggested by DOE. The Commission is also proposing to adopt the petitioner's request that the phrase "at all
- ti mes" be deleted from the performance objective that applies to prec l osure
, operations. In all other respects. the petition is denied.
The reasons for the action. insofar as it both grants and denies parts of the petition. are set out at length in the statement of considerations accompanying the proposed rule.
-""{A )A,,
Dated in Rockville. Maryland. this - /S--day . ,I
_ _ . 1995.
of___,__/,&....-!~
For the Nuclear Regulatory Commission
~.~
John Va;Ho.Yie Secre:y of the Commission PIii /pO- ,@
(55FR.<<8?'71)
Department of Energy UJC: l ED Washington, DC 20585 USNRC
'90 NOV 29 A8 :56 NOV 2 6 1990 Secretary U.S. Nuclear Regulatory Commission Attention: Chief, Docketing and service Branch Washington D.C. 20555
Dear Sir:
This letter and its enclosure constitute the Department of Energy's (DOE) comments on the Federal Register Notice published on July 13, 1990. The notice (55 FR 28771-28773) publishes for public comment receipt of a petition for rulemaking filed by DOE requesting that the U.S. Nuclear Regulatory Commission (NRC) amend its regulations pertaining to the disposal of high-level radioactive wastes in geologic repositories to include a specific dose criterion for design basis accidents.
DOE has reviewed NRC's related regulatory initiative. We urge you to proceed with the DOE's petition for rulemaking now and have specific comments in response to your notice of receipt of petition for rulemaking, as provided in the enclosure.
We appreciate the opportunity to comment on your Federal Register Notice. We were granted an extension by Michael T. Lesar, Chief, Rules Review Section, Regulatory Publications Branch, Division of Freedom Information and Publications Services, Office of Administration, NRC, until December l, 1990. If you have any questions, please contact Dwight Shelor of my staff at (202) 586-6046.
sincerely,
? - ~-
John w. Bartlett, Director Office of Civilian Radioactive Waste Management
Enclosure:
Department of Energy Comments on Notice of Receipt of Petition for Rulemaking (55 FR 28771-28773)
JAN 2 8 1991 y card ....... ,...,,,...,., ** ,, ....
_ JL ,TORY COMMl2 CKETI G SERVICE SECTI OFFICE Of" THE SECRETARY OF HE COMMISSION Document Statistics 0
uced . . ;j;.__
tton t?,os, PDR,
2 cc w/ enclosure:
R. Bernero, NRC R. Browning, NRC J. Youngblood, NRC D. Moeller, ACNW R. Loux, State of Nevada M. Baughman, Lincoln County, NV D. Bechtel, Clark County, NV
- s. Bradhurst, Nye County, NV
Department of Energy Comments on Notice of Receipt of Petition for Rulemaking (55 FR 28771-28773)
Docket No. PRM-60-3 General Comment The NRC acknowledges that the petition addresses areas of concern similar to those that would be addressed in an NRC contemplated rulemaking action to establish additional preclosure regulatory requirements for HLW geologic repositories. The NRC's approach involves performing a functional analysis, followed by development of operational criteria and comparison studies, and using the results of that effort as a basis for consideration of any potential rulemaking. The NRC estimates that the reports of the above effort would be available after November 1991. Accordingly, any potential rulemaking action would not be initiated until after November 1991 and issuance of any final rule could well be 2 or 3 years away from that date. The absence of quantitative accident dose criteria in 10 CFR Part 60 creates programmatic uncertainties associated with the design of the geologic repository operations area and the procurement of long lead-time items based on that design. This concern prompted DOE to take the initiative to submit the subject petition for rulemaking to establish accident dose criteria. DOE strongly urges NRC to undertake an accelerated schedule with regard to resolution of this issue.
Specific Comments NRC states that "In applying the approach of the petitioner, it would be possible to have no structures, systems, and components important to safety if the nearest boundary of the preclosure control area were sufficiently distant.
This could encourage extending the boundary of the preclosure control area in order to justify less effective safety design and quality assurance measures and result in inferior structures, systems, and components in the geologic repository operations area. While {DOE's} approach might be adequate for protection of the general public, it would ignore the safety of the workers."
We disagree with NRC's interpretation of DOE's approach in its petition. DOE is aware of its responsibility of ensuring public and worker safety. The guidance provided in section 4.l(b) of NUREG-1318,* "Criteria for Non-Q-list Items" states that DOE should implement a program addressing "items and activities, such as those associated with meeting the design criteria contained in 10 CFR 60.13l(a) for protection of worker health and safety".
DOE intends to meet the guidance provided in NUREG-1318 in its quality assurance program, which is subject to review by NRC. In addition, protection of worker safety and health would also be assured by the Department's compliance with 10 CFR Part 20.
- NUREG-1318, Technical Position on Items and Activities in the High-Level Waste Geologic Repository Program Subject to Quality Assurance Requirements, U.S. Nuclear Regulatory Commission, April 1988 1
DOE notes that the prov1s1ons currently contained in 10 CFR Part 60 could lead to the type of scenario that is depicted in the above NRC comment. For example, nothing in the current definition of "important to safety" contained in 10 CFR Part 60, precludes one from choosing a sufficiently distant boundary for the "restricted area" so as to result in the same scenario postulated in the NRC comment.
DOE's purpose for proposing a preclosure control area boundary, at which accident dose criteria would be applied, is to rectify an inconsistency that exists in 10 CFR Part 60 compared to other NRC regulations governing nuclear facilities (e.g., 10 CFR Part 72). Other nuclear facilities, such as reactors and independent spent fuel storage installations, typically use two separate area boundaries: 1) an area over which control can be exercised in case of an accident, and 2) a different but much smaller area for access control and routine radiation monitoring for normal operations. Examples are: "Controlled Area", defined in 10 CFR Part 72 for application of accident dose criteria; and "Restricted Area", defined in 10 CFR Part 20 for application of dose criteria during normal operations. 10 CFR Part 60 is inconsistent with such long established practice by requiring that both the accident dose criteria and the routine access controls be applied at the "restricted area" boundary.
At the same time, the definition of "restricted area" in 10 CFR Part 60 remains identical to that of 10 CFR Part 20. As illustrated in the diagram accompanying its petition, DOE seeks to rectify such inconsistency by proposing an area boundary called "preclosure control area" where accident dose criterion will be applied. The term "preclosure control area" (which could be larger than the restricted area, but smaller than the controlled area) would be similar to the term "controlled area" as defined in 10 CFR Part
- 72. The definition of the term "restricted area" remains unchanged and will be used for normal operations considerations, as intended in 10 CFR Part 20.
The approach suggested by NRC, in its July 13, 1990 Federal Register Notice, to determine structures, systems and components important to safety, departs from the objective dose based criterion that NRC adopted, in response to public comments, when 10 CFR Part 60 was promulgated. In addition, a similar dose based criterion approach is used for safety related electrical equipment in 10 CFR Part 50.49. Instead, the suggested approach appears to use as a basis, some arbitrary, highly subjective functional criteria that are yet to be developed. DOE is concerned that NRC intends to abandon the approach to safety classification that it adopted in 10 CFR Part 60 and NUREG-1318, and is not aware of any developments that would justify such action since Part 60 was promulgated. If the NRC intends to pursue a functional analysis approach, it raises a question concerning the status of guidance provided in NUREG-1318, which defines items important to safety on a dose based criterion.
2
Editorial Comments
- 1. Page 28772 (a) Line 1: Change "references" to "Important to Safety" "reference" (b) Line 6: Change "and" to "an"
- 2. Page 28772 Line 4: Change "Licenses" to "licensee" "Preclosure Control Area"
- 3. Page 28772 Paragraph 4, line 5: Change words "In "Supporting Information" claims" to "The petitioner claims"
- 4. Page 28772 Paragraph 6, line 12: Add "a" between the "Supporting Information" words "to" and "size" 3
DOCKET NUMBER I ~ )
PROPOSED RULE fY) {p 0- 3 ~
_ lntertech Consultants ____(s:_s F_~_a8_71~C)_ _ _ __
PLANNING - ECONOMICS - PROGRAM MANAGEMENT October 9, 1990 Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, DC 20555 Attention: Docketing and Service Branch RE: Comments To Petition For Rulemaking - Docket No. PRM-60-3
Dear Sir:
On behalf of Lincoln County, Nevada and the City of Caliente, Nevada, the following comments to a Petition for Rulemaking submitted by the U.S. Department of Energy (Docket No. PRM-60-3) are provided for your consideration. By its petition, DOE seeks to have 10 CFR Part 60 amended to include a specific dose criteria for design basis accidents. DOE asserts that inclusion of such criteria are essential if existing uncertainties regarding the determination of repository adequacy in protecting public health and safety are to be reduced or eliminated.
The County and City would concur in the need to reduce programmatic uncertainty, particularly where it concerns public health and safety. DOE's justification for the proposed rulemaking is largely grounded in a desire to reduce procedural uncertainty. It is suggested here that beyond uncertainty associated with process, the lack of specific dose criterion may imply significant perceived uncertainty about the degree of public health and safety protection afforded by repository structures, systems, and components. The public may therefor be unable to effectively judge the adequacy of such facility attributes. Perceived facility risks may consequently be heightened and public acceptability of the facility further diminished.
Despite the apparent need to establish specific dose criterion, the mlffiediacy of the need has not been established by DOE. Given that NRC hns undertaken a series of studies which may serve to further inform the basis for dose criterion, it would appear prudent to delay initiation of the rulemaking proceedings until such information is available.
Lincoln County and the City of Caliente would suggest that further consideration be given by DOE and NRC to both the definition of preclosure control area and the exposure pathways under which the effective dose is assumed to be administered. Concerning the former, protection of facility workers should be of equal importance to protection of off-sjte publics. With regard to exposure pathways, the exclusion of ingestion is not sufficiently justified in the petition. Because of the inability of the licensure proceedings to gauranke that emergency management procedures will be effective]y designed and/or implemented, the existence of grower-consumed agricultural products being grown within Lincoln County areas immediately downwind of the repository site should be explicitly 35 Clark Road
- Fiskdale, Massachusetts 01518 * (508) 347-5040
- FAX (508) 3 -5445 Acknowledged by card Bo 1 mUffHIH............... -
i
A~ AffiULATORY COMMISSIOl'I TING &SERVICE SECTION E OF THE S CRETAR-OF THE COMMI $ION Document t ti tics
Page 2 Secretary of the Commission October 9, 1990 considered.
DO E's finding that the estimated risk of a committed dose equivalent of 50 rem falls within the range of acceptable risk level as defined by the NCRP and ICRP, should be qualified as being near the upper-bound of acceptability. Further, although exposures from accidents may be highly unlikely, such low-probability/high-consequence accidents are precisely those for which the public has been shown to be most concerned.
SAJiJR Mike L. Baughman Principal cc: Judy Foremaster, City of Caliente Geri Ann Stanton, Lincoln County
101 Pennsylvania Avenue, NW Washington D.C. 20004-2696 DOCKET NUMBER Telephone 202-508-5750 PETITION RULE PAM ~--3 COCKETEO (SS-R: ~f'77 I) us~mc
- 90 OCT 12 A10 :51 EDISON~ELECTRIC :- ; c:.,- C~t.-1 l, r '
LORING E. MILLS INSTITUTE Vice President, Nuclear Activities
-ING* ;, sr: 1c .
-.i
! iU, lii,I; October 11, 1990 Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attn: Docketing and Service Branch Re: Department of Energy; Receipt of Petition for Rulemaking; Docket No. PRM-60-3: 55 Fed. Reg. 28771 (July 13, 1990).
Dear Sir:
This letter is the Edison Electric Institute's and the Utility Nuclear Waste and Transportation Program's (EEI/UWASTE) response to the petition for rulemaking filed by the U.S. Department of Energy (DOE) with the U.S. Nuclear Regulatory Commission (Commission) seeking amendments to 10 C.F.R. Part 60, the regulatory provisions governing the design and licensing of a geologic repository for the disposal of high-level radioactive wastes under the Nuclear Waste Policy Act of 1982 (NWPA),
as amended. The DOE's petition requests that the Commission amend 10 C.F.R. Part 60 to incorporate therein specific quantitative accident dose criteria for repository pre-closure activities and to make certain other conforming changes. As requested by the Commission in the Federal Register notice, we also address the Commission's contemplated rulemaking action to establish additional preclosure regulatory requirements for the repository.
Edison Electric Institute is the association of the Nation's investor-owned electric utilities. Its members generate approximately 75% of all the electricity in the nation.
EEI/UWASTE is a group of 50 electric utilities with nuclear energy programs that takes actions necessary to ensure that safe, environmentally sound, publicly acceptable, and cost-effective radioactive waste management and disposal and nuclear material transportation systems are maintained and developed in a timely manner.
FEB 011JIJ1
Secretary of the Commission October 11, 1990 Page 2 Based on a thorough review of DOE's rulemaking petition, as well as industry experience with the Commission's regulatory regime, EEI/UWASTE supports DOE's request that the Commission adopt criteria, to be incorporated in 10 C.F.R. Part 60, that would specify the maximum dose that an individual "off-site" of the repository could receive in the event of an accident before permanent closure. The Commission's decision not to promulgate specific quantitative accident dose criteria when it adopted Part 60 has injected a significant element of regulatory uncertainty into its repository licensing standards. This uncertainty, if unresolved, could result in significant delays in the NRC Staffs evaluation of the DOE's license application and in the licensing process due to the need both to determine the appropriate accident dose criteria and to determine whether the repository design satisfies those criteria.
Moreover, absent clearly defined accident dose criteria, the DOE will essentially be developing a repository system without knowing one of the criteria that must be satisfied to obtain a license, a situation that could require a major redirection of design efforts at a very late stage in the design process. As explained in DOE's petition, the Commission has considerable information and knowledge concerning the types of operations that will occur at the repository based on the experience gained from decades of similar operations at other licensed facilities. NRC, therefore, has a solid basis for establishing acceptable accident dose criteria at this time. Accordingly, given the significant benefits that could be gained from an early definition of acceptable accident dose criteria (both to DOE's efforts and the Commission's regulatory review),
and the potential costs to the repository program if quantitative accident dose criteria are not adopted well in advance of DOE's submittal of a license application, EEI/UWASTE strongly urges the Commission to act favorably on DOE's petition.
The specific accident dose criteria proposed by DOE in its petition -- 5 rem effective dose equivalent, applied at a preclosure control area boundary (with a limit of 50 rem on the committed dose equivalent to any organ) -- represent reasonable, conservative and appropriate accident dose criteria that will assure adequate protection of public health and safety. As DOE points out in its petition, these proposed accident dose criteria are consistent with the dose criteria established by the Commission for accidents at other licensed facilities, including those applicable to nuclear power reactors (10 CFR Part 100), independent spent fuel storage installations and monitored retrievable storage facilities (10 CFR Part 72). Moreover, as DOE also explains in its petition, these values are well within the acceptable risk level recommended by the most recent reports addressing acceptable radiological risk to members of the public.
Secretary of the Commission October 11, 1990 Page 3 DOE's use of effective dose equivalent to measure the radiation dose experienced by a member of the public is consistent with the dose measurement approach adopted by the International Commission on Radiological Protection and the National Council on Radiation Protection and Measurements. It is also the approach recently adopted by the Commission in its proposal to amend 10 CFR Part 20. The definitions adopted in conjunction with any amendments to Part 60 in response to the DOE's petition should be consistent with any definitions adopted for purposes of Part 20 or other provision of the Commission's regulations.
EEI/UWASTE also supports the additional changes to Part 60 proposed by DOE as consistent with its proposed accident dose criteria. The definition of a separate preclosure control area boundary, at which the accident dose criteria would be applied and is larger than the boundaries of the area required to be controlled during normal operations, makes practical sense and is consistent with Commission regulations governing other licensed facilities. [See 10 C.F.R. §100.11 and §72.106(a).] Similarly, EEI/UWASTE agrees with DOE concerning the appropriate relationship between the accident dose criteria and the "important to safety" threshold for the application of engineered safety features to mitigate accident consequences. Specifically, the current definition of "important to safety" for purposes of Part 60 should be modified to make clear that mitigation of the radiological consequences of accidents through engineered safety features would not be required unless the projected consequences of the accident would exceed the accident dose criteria. This modification is necessary to make the general design criteria for the repository consistent with the quantitative accident dose criteria adopted by the Commission. Moreover, because the accident dose criteria represent the acceptable level of risk to the public resulting from a repository accident, modification of the "important to safety" definition as proposed by DOE will ensure adequate protection of public health and safety.
The Federal Register notice expresses a concern that under DOE's proposal, the preclosure control area boundary could be located so as to compromise the safety of the general public or repository workers. The alleged compromise would occur, because NRC fears that all structures, systems or components would be sufficiently distant from the boundary that they will not be classified as "important to safety."
EEI/UWASTE does not share this concern. The accident dose criteria would be only one component of a detailed regulatory regime that would also include, for example, regulations governing acceptable occupational doses. DOE's proposal to define a separate preclosure control area boundary is based on practical considerations and
Secretary of the Commission October 11, 1990 Page 4 experience with other licensed facilities, not an attempt to circumvent the Commission's regulatory requirements. Other regulations, such as 10 CFR Part 20, would continue to apply.
To the extent that the Commission's concern over DOE's proposed redefinition of systems, structures and components important to safety for purposes of part 60 stems from the inconsistency of that proposed definition with the definitional section of Part 72, EEI/UWASTE believes that such concern is unfounded. Part 60 and Part 72 contain the licensing requirements for different types of facilities designed for different purposes. It is therefore appropriate for the regulations adopted in each of those subparts to reflect the unique operational considerations and risks posed by the particular facility to be licensed thereunder. Adoption of DOE's proposed modification of the Part 60 definition therefore would not create the definitional inconsistency with Part 72, but rather would revise the definitional section of Part 60 to reflect appropriately the adoption of quantified accident dose criteria and the risks posed by a high-level radioactive waste repository. If there is any inconsistency, perhaps the better approach would be to make Part 72 consistent with Part 60, rather than vice-versa.
At the conclusion of the notice, the Commission notes that it is contemplating a rulemaking that would change the fundamental approach adopted in Part 60. From the limited information available concerning the Commission's plans, it appears that this rulemaking initiative would be far broader in scope than DOE's proposal to modify Part 60 through the adoption of quantified accident dose criteria. However, the Commission will not be in a position to make a decision on whether to proceed with this rulemaking until November 1991, at the earliest, when the technical studies addressing this new regulatory approach are scheduled for completion. Given these scheduling considerations, and the significant uncertainty as to whether the Commission's contemplated rulemaking action will in fact be initiated, EEI/UWASTE believes that the Commission should proceed to address the merits of DOE's petition in a timely manner, rather than delay action thereon pending a decision on a broader restructuring of Part 60. As noted above, favorable Commission action on DOE's petition would facilitate DOE's repository development efforts by adding a necessary measure of certainty to the licensing regime. Moreover, the adoption of specific accident dose criteria at this time would not foreclose further modifications to Part 60 at a later date.
Secretary of the Commission October 11, 1990 Page 5 Accordingly, for the foregoing reasons, EEI/UWASTE supports the DOE's proposal that the Commission revise Part 60 through the adoption of quantified accident dose criteria and make certain conforming changes to the definitional portion of Part 60.
EEI/UWASTE requests that the Commission consider DOE's proposal on its merits at the close of the comment period, and not defer action on DOE's petition pending a decision on the Commission's contemplated rulemaking initiative to restructure Part 60.
Sincer9y,
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DOCKET NUMBER l
PETITION RULE PRM (r;()-8 /7J
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U. S . Nuclear Regulatory Comm1ss1on RRANc ~
Washington, DC 20555 .
Attention: Docketing and Service Branch The following are comments on Docket No. PRM-60-3, Petition of the U.S. Department of Energy for a Rulemaking to Establish Accident Dose Criteria for a Geologic Repository for High-Level Radioactive Waste (10 CFR 60), as requested in the Federal Register, Volume 55, No. 135:
- 1. The proposed revision to the definition of "important to safety" uses the term "engineered safety feature", which needs to be defined.
Engineered safety features do not appear to be any different than items important to safety; if there is no difference, the terms are redundant and the term "engineered safety feature" is unnecessary.
- 2. The proposed additional requirements for accident analyses (new section 10 CFR 60.111 b) include an accidental dose limit that is different than the limit for identifying items important to safety.
Items important to safety should include all structures, systems, and components that are needed to reduce accidental doses below the accident dose limit; therefore, these numerical limits should be the same. If the dose value used to identify items important to safety is less than the dose value used to limit accident analyses (as currently proposed), then the regulations will be unclear about how to apply design and quality assurance requirements to items whose failure could result in accidental doses than are between the two values (i.e.,
Concerned U.S. Citizen
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- 4 Nuclear Regulatory Commission 10 CFR Part 60
[Docket No. PRM-60-3]
Department of Energy; Receipt of Petition for Rulemaking, Correction
- AGENCY: Nuclear Regulatory Commission.
ACTION: Petition for rulemaking; Notice of receipt, Correction.
SUMMARY
- This document corrects a notice of receipt of petition for rulemaking filed by the U.S. Department of Energy which was published in the Federal Register on July 13, 1990 (55 FR 28771). This action is necessary to correct two typographical errors.
FOR FURTHER INFORMATION CONTACT: Michael T. Lesar, Chief, Rules Review Section, Regulatory Publications Branch, Division of Freedom of Information and Publications Services, Office of Administration, U.S.
Nuclear Regulatory Commission, Washington, DC 20555, Telephoney 301-492-7758.
In the Federal Register of July 13, 1990, in the center column of page 28773, make the following corrections:
- 1. In the eighth line of the first complete paragraph of the document "the" should be changed to read "that."
- 2. In the tenth line of the document remove the word "that."
Dated at Bethesda, Maryland, this 3 r_!::; day of August 1990.
For the Nuclear Regulatory Commission.
David L. Meyer, Chief Regulatory Publications Branch Division of Freedom of Information and Publications Services Office of Administration
DOCKET NUMBER PETITION RULE PAM ~0-.3 (55 FR. z &>7 'l;) DOCKETED USNRC
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NUCLEAR REGULATORY COMMISSION 10 CFR Part 60
[Docket No. PRM-60-3]
U.S. Department of Energy; Receipt of Petition for Rulemaking AGENCY: Nuclear Regulatory Commission.
ACTION: Petition for rulemaking; Notice of receipt.
SUMMARY
- The Nuclear Regulatory Commission (NRC) is publishing for public
-comment a notice of receipt of a petition for rulemaking which was filed by the U.S. Department of Energy (DOE). The petitioner requests that the NRC amend its regulations pertaining to the disposal of high-level radioactive wastes in geologic repositories to include a specific dose criterion for design basis accidents. The petitioner believes this would facilitate the development and licensing of a geologic repository for high-level radioactive waste.
DATE: Submit comments by (90 days after publication). Comments received after this date will be considered if it is practical to do so but the Commission is able to ensure consideration only for comments received on or before this date.
ADDRESSES: Submit written comments to the Secretary of the Commission, U.S.
Nuclear Regulatory Commission, Washington, DC 20555, Attention: Docketing and Service Branch.
For a copy of the petition, write the Regulatory Publications Branch, Division of Freedom of Information and Publications Services, Office of Administration, U.S. Nuclear Regulatory Commission, Washington, DC 20555.
The petition and copies of comments received may be inspected and copied for a fee at the NRC Public Document Room, 2120 L Street NW. (Lower Level),
Washington, DC.
FOR FURTHER INFORMATION CONTACT: Michael T. Lesar, Chief, Rules Review Section, Regulatory Publications Branch, Division of Freedom of Information and Publications Services, Office of Administration, U.S. Nuclear Regulatory Commission, Washington, DC 20555, Telephone: 301-492-7758 or Toll Free:
800-368-5642.
SUPPLEMENTARY INFORMATION:
Background
On April 19, 1990, the U.S. Department of Energy (DOE) filed a petition
-for rulemaking with the Commission. Pursuant to 10 CFR 2.802, this petition was docketed by the Commission on April 26, 1990, and has been assigned Docket No. PRM-60-3.
The petition pertains to the requirements that would apply to DOE as the licensee for a geologic repository for high-level radioactive waste developed pursuant to the Nuclear Waste Policy Act, as amended, 42 U.S.C. 10101 et seq.
As a licensee, DOE would be subject to the licensing requirements contained in 10 CFR Part 60. In its petition, DOE observes that§ 60.21(c)(3)(ii) requires that the Safety Analysis Report for a repository include a description and analysis that considers "the adequacy of structures, systems, and components provided for the prevention of accidents and mitigation of the consequences of accidents, including those caused by natural phenomena," yet Part 60 does not provide numerical dose criteria to use in identifying the need for engineered safety features and for determining their adequacy. The petitioner believes that specific accident dose criteria are necessary to reduce the uncertainties in the current regulation and to provide specific guidance for the protection of public health and safety.
2
The Suggested Amendments The petitioner requests that the NRC amend 10 CFR Part 60 to include quantitative accident dose criteria of 5 rem effective dose equivalent, with a limit of 50 rem on the committed dose equivalent to any organ. To accomplish the desired amendment, the petitioner suggests that definitions be added for 11 preclosure control area," "co111T1itted dose equivalent," 11 co1T1T1itted effective dose equivalent," and "effective dose equivalent." The petitioner believes these definitions are needed to support the application of accident dose criteria.
The petitioner also believes there is a need to include a revision to the current definition of "important to safety." The specific amendments suggested by the petitioner are as follows:
- 1. In §60.2, the definition of "important to safety" is revised and definitions of "committed dose equivalent, 11 11 corrvnitted effective dose equivalent," "effective dose equivalent," and 11 preclosure control area 11 are added to read as follows:
§60.2 Definitions.
"Committed dose equivalent," means the dose equivalent to organs or
-tissues of reference that will be received from an intake of radioactive material by an individual during the 50-year period following the intake.
"Committed effective dose equivalent," means the sum of the products of the weighing factors applicable to each of the body organs or tissues which are irradiated and the committed dose equivalent.
"Effective dose equivalent," means the sum of the products of the dose equivalent to the organ or tissue and the weighing factors applicable to each of the body organs or tissues which are irradiated.
3
"Important to safety," with references to structures, systems, and components, means those engineered structures, systems, and components the failure of which could result in a release of radioactive material that produces an effective dose equivalent of 0.5 rem or greater to an individual located at or beyond the nearest boundary of the preclosure control area for an accident that could occur at any time until the completion of permanent closure. All engineered safety features shall be included within the meaning of the term "important to safety."
"Preclosure control area," means the area immediately surrounding the repository facilities for which the licenses exercises authority over its use during the period up to completion of permanent closure. This area may be traversed by a highway, railroad, or waterway, so long as appropriate and effective arrangements are made to control traffic and to protect public health and safety.
- 2. In §60.111, paragraph (a) is amended by removing "at all times,"
-paragraph (b) is redesignated as paragraph (c), and a new paragraph (b) is added to read as follows:
§ 60.111 Performance of the geologic repository operations area through permanent closure.
(b) Accident analysis. The geologic repository operations area shall be designed such that any individual member of the public located at or beyond the nearest boundary of the preclosure control area shall not receive a radiation dose from direct exposure and inhalation greater than 5 rem effective dose equivalent or 50 rem committed dose equivalent to any organ from any accidents considered in the design of the repository that could occur at any time until the completion of permanent closure.
4
Supporting Information The purpose of this proposed amendment is to establish quantitative accident dose criteria and to provide pertinent definitions to facilitate application of these criteria.
The petitioner considers the current rule deficient in that it does not contain the numerical dose criteria needed to determine design adequacy. The petitioner believes that the absence of quantitative accident dose criteria creates programmatic uncertainties associated with the design of the geologic repository operations area and the procurement of long lead-time items based on that design and that uncertainty could result in major redirection of design efforts and possibly affect the schedule for development of a geologic repository.
The petitioner points out that considerable knowledge and experience in the type of handling operations that will occur at a repository exists. In particular, activities at a geological repository would be similar to activities that occur at other nuclear facilities, including several facilities licensed by the NRC, and others operated by DOE. These activities will include the receipt, handling, transfer, and storage of highly radioactive materials, principally spent nuclear fuel assemblies and canisters of vitrified high-level radioactive waste. Similar or identical operations with highly
-radioactive materials are, or have been, performed routinely at facilities for independent storage of spent nuclear fuel.
The petitioner maintains that its proposed repository dose criteria are within the range of accident dose criteria established by the NRC for similar activities. It claims that proposed dose criteria would be consistent with the 5 rem criteria established by the NRC for accidents at facilities for independent storage of spent nuclear fuel and high-level radioactive waste (10 CFR Part 72) and even more conservative than the 6.25 rem criteria for nuclear power plant fuel handling accidents, including accidents involving drops of heavy loads on fuel assemblies or safety-related systems, components, or equipment. (For further information, DOE refers to NUREG-0800, Standard Review Plan, and NUREG-0612, Control of Heavy Loads at Nuclear Power Plants).
Postulated accident scenarios include crane failures and other waste handling 5
accidents that may result in damage to the waste canister such that there is a breach of confinement barrier.
The petitioner considers the 5 rem effective dose equivalent accident dose criteria to be supported by accepted radiological protection criteria. DOE proposes that the 5 rem accident dose criteria be expressed in the form of effective dose equivalent, as defined by the International Commission on Radiological Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRPM), and be applied to the sum of the effective dose equivalent from external exposure and the coRlllitted effective dose equivalent from intake of radionucludes. To avoid nonstochastic effects, DOE is proposing that the accident dose criteria include a limit of 50 rem on the committed dose equivalent to any organ. For dosimetric purposes, DOE recommends that the dose criteria be applied to a member of the public who is generally representative of the exposed population (i.e., reference man), as is done with other NRC accident criteria. The exposure pathways to which the accident dose criteria would apply should be limited to direct irradiation and inhalation.
In the petitioner's view, the accident dose criteria should be applied at the boundary of a newly defined preclosure control area. The restricted area defined in 10 CFR 60.2 is used for both the area to be controlled in case of a radiological accident and the area controlled under normal operations. The petitioner believes that this area is unnecessarily large for application of
-normal access controls and radiological monitoring. To reduce the size of this area to a size that the petitioner deems more appropriate, it would be necessary to establish separate boundaries for the two controlled zones (i.e., accident and routine access control). For a repository, DOE proposes to define the location for application of the accident dose criteria and the "important to safety" threshold as the precl.osure control area" boundary.
11 The petitioner believes that establishment of accident dose criteria would not change the intent of the 0.5-rem "important to safety" threshold for classification. However, in its view, the current definition of "important to safety" would need to be modified to be consistent with other changes it has suggested. The current definition could be interpreted to mean that an accident resulting in a radiation dose of 0.5 rem or greater must be mitigated:
6
"those engineered structures, systems, and components essential to the prevention or mitigation of an accident *** " (10 CFR 60.2, emphasis added).
The threshold for determining the need for mitigation through the use of engineered safety features is the accident dose criterion, not the "important to safety" threshold. The petitioner suggests modification of the current definition "important to safety" to make it consistent with the proposed accident dose criterion by incorporating the effective dose equivalent concept and the new preclosure control area boundary.
Related NRC Regulatory Initiative In the NRC Regulatory Agenda (NUREG-0936, Vol. 8, No. 4, published January 1990) and in the Unified Agenda of Federal Regulations (55 FR 17174; April 23, 1990), the NRC has announced a contemplated rulemaking action that would establish additional preclosure regulatory requirements for high-level waste geologic repositories (RIN 3150-AD51). The subject matter of the DOE petition relates closely with the actions under consideration by the NRC as part of this rulemaking effort.
The NRC approach to this related regulatory initiative includes plans to:
- 1. Perform a functional analysis of a geologic repository using a systematic approach. This functional analysis would include an evaluation of
-the preclosure operations phase of a repository.
- 2. Identify in this analysis the functions necessary to protect the health and safety of the workers and the public during normal conditions and abnormal conditions (e.g. design bases accidents/events).
- 3. Develop repository operational criteria for each function necessary to protect the health and safety of the workers and public.
- 4. Compare these repository operational criteria to the current criteria in 10 CFR Part 60 to help identify any potential regulatory uncertainties.
- 5. Use the results of the functional analysis and comparison studies as a basis for consideration of any potential rulemaking.
The NRC is in the process of obtaining studies that would address potential regulatory uncertainties in this area. The results of these studies would be made available as NUREG reports. These studies would provide technical support 7
for any regulatory action that may be needed. The NRC estimates that these reports would be available after November 1991.
Although DOE's petition does address areas of concern similar to those addressed in the NRC regulatory initiative described above, the petitioner's approach to establishing design criteria for structures, systems, and components important to safety differs markedly from that contemplated by the NRC. In dpplying the approach of the petitioner, it would be possible to have no structures, systems, and components important to safety if the nearest boundary of the preclosure control area were sufficiently distant. This could encourage extending the boundary of the preclosure control area in order to justify less e effective safety design and quality assurance measures and result in inferior structures, systems, and components in the geologic repository operations area.
While this approach might be adequate for protection of the general public, it would ignore the safety of the workers.
In contrast, in applying the approach proposed by the NRC staff, the scope of, and the design criteria for, structures, systems, and components important to safety would be derived from a consideration of the functional requirements of the repository system. In addition, criteria for a preclosure controlled area that takes into account postulated accident conditions that may be developed as a matter apart from the question of structures, systems, and components important to safety. The corresponding provisions in 10 CFR Part 72
. a y be considered as possible models for regulatory language in this context.
Comments are solicited with respect to the NRC's regulatory initiative as well as the DOE petition.
Dated in Rockville, Maryland this 9cf day of It> 7* 1990.
r the Nuc r Regulatory Commission.
Secretary of the Commission.
8
DOCKET NUMBER .
PETITION RULE PAM (o 0- ..3 {!j5 FR_ 2 g 7 7)
Department of Energy DOCKETED Washington, DC 20585 USNRC APR 1 9 1990 *90 APR 25 A10 :48 Secretary U.S. Nuclear Regulatory Commission Attention: Chief, Docketing and Service Branch Washington, D.C. 20555
Dear Sir:
The U.S. Department of Energy believes that to facilitate the development and licensing of a geologic repository for high-level radioactive waste it is necessary to amend 10 CFR Part 60 to include a specific dose criteria for design basis accidents.
Consequently, we are hereby submitting the enclosed petition for rulemaking under the provisions of 10 CFR 2.802. The subject of this petition has been previously discussed with the Commission's Division of High-Level Waste Management staff and with the Advisory Committee on Nuclear Waste.
We would appreciate your consideration and acceptance of this petition. Any questions regarding the petition may be addressed to Mr. Ralph Stein of my staff on 586-6046.
Sincerely,
?f!::~t~or Office of civilian Radioactive waste Management
Enclosure:
Petition of the U.S. Department of Energy for a Rulemaking to Establish an Accident Dose Criteria for a High-Level Radioactive Waste Repository cc:
R. Bernero, NRC R. Browning, NRC J. Youngblood, NRC D. Moeller, ACNW R. Loux, state of Nevada M. Baughman, Lincoln County, NV D. Bechtel, Clark County, NV
- s. Bradhurst, Nye County, NV
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PETITION OF THE U.S . DEPARTMENT OF ENERGY FOR A RULEMAKING TO ESTABLISH ACCIDENT DOSE CRITERIA FOR A GEOLOGIC REPOSITORY FOR HIGH-LEVEL RADIOACTIVE WASTE Docket No.
1.0 INTRODUCTION
Title 10 of the Code of Federal Regulations, Part 60 , "Disposal of High-Level Radioactive Wastes in Geologic Repositori es , "
does not contain specific accident dose criteria. The Department of Energy (DOE) considers such criteria to be necessary and i s hereby petitioning the Nucl ear Regul atory Commission (NRC ) to amend 10 CFR Part 60 to include accident dose criteria of 5 rem effective dose equivalent with a limit of 50 rem on the committed dose equivalent to any organ. These criteria would apply to any individual at the boundary of a newly defined "preclosure control area" at any time until repository closure is completed.
This petition addresses all the requirements of 10 CFR 2.802 (c).
The proposed amendments to the current rule, 10 CFR Part 60, are included in Section 2, the grounds for and DOE's interest in the action requested are described in Section 3, and a discussion of the specific issues involved, supporting arguments, relevant information, and the reasons why the current rule is deficient are provided in Section 4.
2.0 PROPOSED AMENDMENTS TO 10 CFR PART 60 This section provides a general description of the proposed amendments, followed by specific additions and modifications to the current rule to accomplish the amendments.
2.1 General Description of Proposed Amendments to 10 CFR 60 Amendments are proposed for both 10 CFR 60, Subpart A (General Provisions, Definitions) and Subpart E (Technical Criteria, Performance Objectives).
In Subpart A, definitions are proposed to be added to 10 CFR 60.2 for "preclosure control area", "committed dose equivalent",
"committed effective dose equivalent " and "effective dose equi valent". The current version of 10 CFR Part 60 does not contain these definitions, and they are needed to support the application of accident dose cri teria.
Page _1_. of -1L
Also, a revised definition is proposed for the current definition of "important to safety" provided in 10 CFR 60.2. The current definition requires revision as a result of adding the new "preclosure control area" term, addition of new radiation dose terms, and to clarify that the mitigation of the radiological consequences of accidents is not required if doses resulting from these accidents are below the accident dose criteria.
In Subpart E, quantitative accident dose criteria are proposed for addition to 10 CFR 60.111 as a new performance objective under "Performance of the Geologic Repository Operations Area Through Permanent Closure". This includes the requirement that the calculation be applied at the nearest boundary of a newly defined preclosure control area.
Given the proposed new performance objective, it is proposed that the phrase "at all times" be deleted from the performance objective in 10 CFR 60.lll(a), to clarify that the objective does not apply to exposures from accidents.
2.2 Specific Proposed Amendments to 10 CFR 60 Subpart A - General Provisions. Definitions In 10 CFR 60.2, the following new definitions should be inserted:
"Preclosure control area," means the area immediately surrounding the repository facilities for which the licensee exercises authority over its use during the period up to completion of permanent closure. This area may be traversed by a highway, railroad, or waterway, so long as appropriate and effective arrangements are made to control traffic and to protect public health and safety.
"Committed dose equivalent," means the dose equivalent to organs or tissues of reference that will be received from an intake of radioactive material by an individual during the 50 year period following the intake.
"Committed effective dose equivalent," means the sum of the products of the weighing factors applicable to each of the body organs or tissues which are irradiated and the committed dose equivalent.
"Effective dose equivalent," means the sum of the products of the dose equivalent to the organ or tissue and the weighing factors applicable to each of the body organs or tissues which are irradiated.
In 10 CFR 60.2 the current definition of "important to safety" should be replaced with the following:
Page ..L of ..1L
"Important to safety," with reference to structures, systems, and components, means those engineered structures, systems, and components the failure of which could result in a release of radioactive material that produces an effective dose equivalent of 0.5 rem or greater to an individual located at or beyond the nearest boundary of the preclosure control area for an accident that could occur at any time until the completion of permanent closure. All engineered safety features shall be included within the meaning of the term "important to safety."
2.3 Specific Proposed Amendments to 10 CFR 60 Subpart E - Technical Criteria, Performance Objectives In 10 CFR 60.111, delete "at all times" from (a), Protection against radiation exposures and releases of radioactive materials, (2) move (b), Retrievability of waste, to (c), and (3) insert a new (b):
Accident analyses. The geologic repository operations area shall be designed such that any individual member of the public located at or beyond the nearest boundary of the preclosure control area shall not receive a radiation dose from direct exposure and inhalation greater than 5 rem effective dose equivalent or 50 rem committed dose equivalent to any organ from any accidents considered in the design of the repository that could occur at any time until the completion of permanent closure.
3.0 PETITIONER'S GROUNDS FOR AND INTEREST IN THE PETITION This section describes the DOE's grounds for and interest in the action requested.
The Department of Energy will be the licensee for a geologic repository developed pursuant to the Nuclear Waste Policy Act, as amended. As such, it will be subject to the requirements in 10 CFR Part 60. Section 60.21(c) (3) (ii) requires that the Safety Analysis Report for a repository include a description and analysis that considers "the adequacy of structures, systems, and components provided for the prevention of accidents and mitigation of the consequences of accidents, including those caused by natural phenomena." However, 10 CFR Part 60 does not provide numerical dose criteria to use in identifying the need for engineered safety features and for determining their adequacy. Although the rulemaking record for 10 CFR Part 60 1 1
U.S. Nuclear Regulatory Cornnission, 1983. Staff Analysis of Public Cornnents on Proposed Rule 10 CFR Part 60, "Disposal of High-Level Radioactive Wastes in Geologic Repositories," NUREG-0804.
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shows that some comments suggested such criteria 2 , no such criteria were included in the final rule.
During the advanced conceptual design of the repository, DOE will explore design alternatives, ultimately arriving at firmly fixed and refined design criteria and concepts, with further detail to be provided in later design efforts. The absence of accident dose criteria creates uncertainty about how the adequacy of structures, systems, and components will be determined by the regulators at the licensing phase, and could result in major redirection of design efforts.
The regulatory uncertainties introduced by the absence of accident dose criteria in 10 CFR Part 60 are sufficient to warrant rulemaking, particularly when viewed in light of the NRC's commitment to provide sufficient guidance to protect public health and safety. Therefore, explicit accident dose criteria need to be included in the regulations.
Based on the reasons set out below, the DOE requests the NRC to amend 10 CFR Part 60 to include accident dose criteria of 5 rem effective dose equivalent, with a limit of 50 rem on the committed dose equivalent to any organ. Such criteria are generally consistent with NRC accident dose criteria for similar operations at other nuclear facilities and would provide adequate protection of public health and safety.
4.0 SUPPORTING INFORMATION This section provides a discussion of the specific issue involved in the petition, supporting arguments, and other relevant information, and the reasons why the current rule is considered deficient. The specific issue is whether there is a need to amend 10 CFR Part 60 to include quantitative accident dose criteria and pertinent definitions to facilitate application of the criteria. The current rule is considered deficient simply because it does not specify quantitative criteria. The arguments supporting this position are based on the evaluation of current regulations for similar operations and are not based on an independent assessment of the accident risks associated with those operations or the consequences for potential accidents.
Additional information is provided to support the contention that the proposed criteria are consistent with accepted radiological protection criteria. Also, other relevant information is provided to explain the need for the definition of a preclosure control area, and revision to the current definition of "important to safety".
2 U.S. Nuclear Regulatory Conmission, 1983. Staff Analysis of Public Cooments on Proposed Rule 10 CFR Part 60, "Disposal of High-Level Radioactive Wastes in Geologic Repositories," NUREG-0804, Conment Nl.lllbers 326-327.
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The current rule is considered deficient in that it does not contain the numerical dose criteria needed to determine design adequacy.
As indicated above in Section 3, 10 CFR 60.21(c) (3) (ii) requires an analysis that considers adequacy with respect to potential repository accidents considered. However, the current rule does not contain the numerical dose criteria to be used in determining such adequacy. The absence of quantitative accident dose criteria in 10 CFR Part 60 creates programmatic uncertainties associated with the design of the geologic repository operations area and the procurement of long lead-time items based on that design. This uncertainty could result in major redirection of design efforts and possibly affect the schedule for development of a geologic repository.
There exists a considerable body of knowledge and experience in the type of handling operations that will occur at a repository.
Activities at a geologic repository will be similar to activities that occur at other nuclear facilities, including several facilities licensed by the NRC, and others operated by DOE.
These activities will include the receipt, handling, transfer, and storage of highly radioactive materials, principally spent nuclear fuel assemblies and canisters of vitrified high-level radioactive waste. Similar or identical operations with highly radioactive materials are, or have been performed routinely at facilities for independent storage of spent nuclear fuel, such as General Electric's Morris Operations, at commercial nuclear power plants, such as Virginia Power Company's Surry nuclear power plant and others, at commercial fuel cycle facilities, such as Nuclear Fuel Services (NFS) West Valley Reprocessing Plant, and at DOE facilities, such as Savannah River Plant (SRP), Hanford, Engine Maintenance and Disassembly Facility (EMAD), and Idaho National Engineering Laboratory (INEL).
Specific operational similarities include (1) cask handling and cask unloading, (2) spent fuel loading into casks and containers, (3) spent fuel storage, and (4) spent fuel transfers within facilities. Cask handling and unloading operations have been performed at commercial reactors and at such facilities as Morris, NFS, SRP, Hanford, and INEL. At a repository, it is anticipated that spent fuel assemblies will be removed from shipping casks and loaded into disposal containers under dry conditions. This has been done at EMAD. At Morris, spent fuel assemblies are removed from shipping casks and loaded into fuel storage baskets, which are then transferred to the storage basins. With the exception of the operations being conducted underwater, this fuel storage basket loading operation is similar to the fuel container loading operation expected to occur at a repository. The same is also true for the loading of spent fuel Page l of _..11._
assemblies into shipping casks at commercial nuclear power plants. Dry storage, such as would occur at the repository, has been performed at Surry, INEL and Carolina Power and Light's (CP&L) H.B. Robinson nuclear power plant. Similar spent fuel transfer operations have occurred at other nuclear facilities including fuel storage basket transfers at Morris and cask transfers to concrete storage pads at Surry. Thus, there exists a considerable body of knowledge and experience in the type of handling operations that will occur at a repository.
The repository accident dose criteria proposed by DOE are within the range of accident dose criteria established by the NRC for similar activities.
In view of the similarity between repository operations and operations at other nuclear facilities, it is reasonable that the accident dose criteria for the repository be generally consistent with existing dose criteria for these operations. The dose criteria proposed by DOE are consistent with the 5 rem criteria established by the NRC for accidents at facilities for independent storave of spent nuclear fuel and high-level radioactive waste and even more conservative than the 6.25 rem criteria for nuclear power plant fuel handling accidents, including accidents involving drops of heavy loads on fuel assemblies or safety-related systems, components, or equipment4
- For the repository, postulated accident scenarios similarly include crane failures and other waste handling accidents that may result in damage to the waste canister such that there is a breach of a confinement barrier5
- 5-rem effective dose equivalent accident dose criteria is supported by accepted radiological protection criteria.
Some of the postulated accident scenarios noted above may result in atmospheric release of radioactive particulates containing, among others, isotopes of cesium, strontium, plutonium, americium, and curium. The dominant exposure pathway for these radionuclides is atmospheric transport followed by inhalation.
The potential doses from inhalation would be greatest in internal organs, with doses to the bone surface being the major concern 3
Code of Federal Regulations, Title 10, Part 72: Licensing Requf rements for the lndepeldent Storage of Spent Nuclear Fuel and High-Level Radioactive Waste, Section 72.106(b), August 1988.
4 U.S. Nuclear Regulatory Conmission, 1981. Section 15.7.4 of the Standard Review Plan,
- Radiological Consequences of Fuel Handling Accidents at Nuclear Power Plants," NUREG-0800; U.S. Nuclear Regulatory Conmission, 1980. "Control of Heavy Loads at Nuclear Power Plants," NUREG-0612.
5 Nevada Nuclear Waste Storage Investigations Project Site Characterization Plan Conceptual Design Report, Vol. 4, Appendix F, SAND84-2641.
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(i.e., bone is the critical organ) and uptake in the liver and retention in the lung being of lesser importance6
- To account for the exposure of multiple organs, DOE proposes that the 5 rem accident dose criteria be expressed in the form of effective dose equivalent, as defined by the International Commission on Radiological Protection (ICRP) 7 and the National Council on Radiation Protection and Measurements (NCRP) 8 , and be applied to the sum of the effective dose equivalent from external exposure and the committed effective dose equivalent from intake of radionuclides.
In addition, to avoid nonstochastic effects, DOE is proposing that the accident dose criteria include a limit of 50 rem on the committed dose equivalent to any organ.
For dosimetric purposes DOE recommends that the dose criteria be applied to a member of the public who is generally representative of the exposed population (i.e., reference man) 9 , as is done with other NRC accident dose criteria. 10 The exposure pathways to which the accident dose criteria would apply should be limited to direct irradiation and inhalation.
Ingestion of contaminated foodstuffs should not be included because the primary determinant of exposure from this pathway is the effectiveness of public health measures taken after the accident (i.e., interdiction of land and foodstuffs) rather than the severity of the accident itself. Criteria for such measures typically fall within the scope of emergency response considerations.
The risk from 5 rem effective dose equivalent is very small.
Based on risk coefficients recommended by the ICRP 11 and NCRP 12 , a 6
Nevada Nuclear Waste Storage Investigations Project, Site Characterization Plan Conceptual Design Report, Vol. 4, Appendix F, SAND84-2641.
7 International Coomission on Radiological Protection, A Compilation of the Major Concepts and Quantities in Use by ICRP, ICRP Publication 42, Ann. ICRP, 14(4): 1-18 (1984).
8 National Council on Radiation Protection and Measurements, Recoomendations on Limits for Exposure to Ionizing Radiation, NCRP Report No. 91, Bethesda, Md., 1987.
9 1nternational Coomission on Radiological Protection, Anatomical, Physiological and Metabolic Characteristics, ICRP Publication 23, Pergamon Press (1975).
10 u.s. Nuclear Regulatory Coomission, Regulatory Guide 3.34, Revision 1, "Assumption Used for Evaluating the Potential Radiological Consequences of Accidental Nuclear Criticality in a Uranium Fuel Fabrication Plant, U.S. Nuclear Regulatory Coomission (July, 1979).
11 International Coomission on Radiological Protection, Recoomendations of the International Coomission on Radiological Protection, ICRP Publication 26, Ann. ICRP, 1(3): 1-53 (1977).
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5 rem effective dose equivalent corresponds to an annual probability of 2x10* 5 of fatality from radiogenic cancer or of a serious hereditary disease (within the first two generations) over a 50 year period following exposure of an individual. (This is the risk to an individual member of the public averaged over both sexes and all ages; the annual risk to any specific individual would depend on age at exposure and time after exposure, and other factors).
Recent reports (i.e., UNSCEAR-88 13 and BEIR-V 14 ) indicate that the risk from exposure to low linear energy transfer (LET) radiation (e.g., gamma and beta rays) may be higher than thought previously. Based on those reports, the annual risk from an acute whole body dose of 5 rem of low LET radiation could be ax10* 5
- The risk would likely be lower if the doses were delivered at a low dose rate. The risk would still be very low, being only about 2% of the current baseline risk of death due to cancer in the United States.
The ICRP recommends that 11 *** a risk in the range of 10* 6 to 10* 5 per year would likely be acceptable to any individual member of the public 1115
- The proposed accident dose criteria are not inconsistent with this range since the low probabilities of repository accidents which could lead to atmospheric radioactive releases would further reduce the overall calculated risk. 16 For radionuclides of primary concern in potential repository accidents, most of the dose commitment to critical organs would be from high LET alpha particles rather than from low LET radiation 17
- For these radionuclides, the dose is likely to be controlled by the 50 rem cap on the dose to the bone surface rather than by the 5 rem effective dose equivalent limit. For 12 National Council on Radiation Protection and Measurements, Reconmendations on Limits for Exposure to Ionizing Radiation, NCRP Report No. 91, Bethesda, Md., 1987.
13 United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), Sources, Effects and Risks of Ionizing Radiation, Report to the General Assembly, with Annexes, New York, United Nations.
(1988).
14 National Research Council, Committee on the Biological Effects of Ionizing Radiation (BEIR-V),
Health Effects of Exposure to Low Levels of Ionizing Radiation, Washington, D.C., National Academy Press
( 1990).
15 International Commission on Radiological Protection, Reconmendations of the International Commission on Radiological Protection, ICRP Publication 26, Ann. ICRP, 1(3): 1-53 (1977).
16 Nevada Nuclear Waste Storage Investigation Project, Site Characterization Plan Conceptual Design Report, Vol. 4, Appendix F SAND84-2641.
17 Nevada Nuclear Waste Storage Investigations Project, Site Characterization Plan Conceptual Design Report, Vol. 4, Appendix F, SAND84-2641.
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example, if the doses to various organs resulting from inhalation of a radionuclide mixture characteristic of 10 year old spent fuel were normalized to 5 rem effective dose equivalent, the corresponding dose to the bone surface would be about 72 rem.
Since this would exceed the 50 rem organ dose limit, the latter would be controlling.
Based on risk coefficients for high LET radiation developed by the National Academy of Sciences (BEIR-IV) 18 , a committed dose equivalent of 50 rem to the bone surface from alpha particles is estimated to result in an annual risk of fatality from bone cancer of about 2x10* 5
- This risk is also consistent with that suggested by the NCRP and the ICRP as acceptable criteria for establishing radiological protection criteria for the public. 19 ,~
It should also be noted that the application of ICRP recommendations regarding acceptability of risk to accident situations is conservative because the recommendations are intended to limit risk from exposures that are expected to occur, 21 whereas exposure from accidents is highly unlikely.
The accident dose criteria should be applied at the boundary of a newly defined preclosure control area.
The regulations for nuclear facilities typically require that there be an area established over which control can be exercised in case of an accident (see 10 CFR 72.106(a)). These regulations usually define a different area to which access is controlled during normal operations to provide for radiation protection measures on a routine basis 2
- In case of a radiological accident, the area within which public access is to be controlled is desired to be large, since the distance provides added 18 National Research Council, Conmittee on Biological Effects of Ionizing Radiation CBEIR-IV),
Health Risks of Radon and Other Internally Deposited Alpha-Emitters, Washington D.C., National Academy Press (1988).
19 National Council on Radiation Protection and Measurements, Reconmendations on Limits for Exposure To Ionizing Radiation, NCRP Report No. 91, Bethesda, Md., (1987).
20 1nternational Conmission on Radiological Protection Recoomendations of the International Conmission on Radiological Protection ICRP Publication 26, Ann. ICRP 1(3): 1-53 (1977).
21 1nternational Conmission on Radiological Protection, Recoomendation of the International Conmission on Radiological Protection, ICRP Publication 26, Ann. ICRP, 1 (3): 1-53 (1977).
22 10 CFR 20 defines a restricted area for this purpose.
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protection independent of design features 23
- In contrast, for practical purposes pertaining to ensuring proper controlled access and radiation monitoring, the area controlled during normal operations is usually maintained as small as practicable.
However, the restricted area defined in 10 CFR 60.2 is used for both of these purposes 24 , which has led the DOE to size a restricted area based on accident considerations. Such an area is unnecessarily large for application of normal access controls and radiological monitoring. To enable DOE to reduce the size of this area to a more appropriate size, it is necessary to establish separate boundaries for the two controlled zones (i.e.,
accident and routine access control). By making this distinction, the DOE will be in a better position to apply the controls needed to ensure a proper and practical level of radiation protection for routine operations.
e The need for separate boundaries was recognized by the NRC when 10 CFR Part 72 was promulgated. In discussing the newly defined "controlled area" for application of the accident dose limit, the NRC stated that "while the terminology used in 10 CFR Part 20, specifically, 'restricted' and *unrestricted' areas, applies to all nuclear facilities, it is limited to radiation protection concerns associated with normal operations and the means used by the licensee to control the access to areas of potential radiation exposure * *
- the term *unrestricted' used in 10 CFR Part 20 is too narrow in meaning for applications to areas beyond the boundaries of the licensee's property 1125
- For other nuclear facilities, the area within the boundary where the accident dose limit is applied is typically on land controlled by the licensee such that the licensee has authority to exclude or remove personnel and property from the area. This area is called the "exclusion area" at reactor sites (see 10 CFR 100.11) and the "controlled area" at facilities for independent storage of spent nuclear fuel and high-level radioactive waste (see 10 CFR 72 106(a)). For a repository, DOE is proposing to define the location for application of the accident dose criteria and the "important to safety" threshold as the 11 preclosure control area" boundary. Figure 1 illustrates the differences between the boundaries which would be proposed and the current 23 For nuclear reactors the Licensee is required by 10 CFR 100.11 to provide an "exclusion area" which is Large enough to Limit doses from any credible accident to a specified value. Facilities Licensed under 10 CFR Part n are required to establish a "control led area" large enough to limit doses from a design basis accident to a specified value. A mininun size for the controlled area is specified.
24 10 CFR 60.2 specifies that the 0.5 rem threshold for identifying structures, systems, and components important to safety should be applied at or beyond the nearest boundary of the restricted area.
10 CFR 60.111 applies the requirements of 10 CFR 20 which defines restricted and unrestricted areas for normal operations use.
25 45 Federal Register 74696 (1980) (codified at 10 CFR Part 72).
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boundaries defined in 10 CFR Part 60. It should be noted that the boundary of the preclosure control area does not necessarily have to coincide with the boundary of the postclosure controlled area defined in 10 CFR 60.2. The shapes of the controlled area and the boundary for accident dose calculation are based on different considerations. For the controlled area, the geohydrologic conditions (e.g. direction of groundwater flow) are important. For the preclosure control area, the meteorological conditions (e.g. predominant wind direction) and population distribution are important.
Establishment of accident dose criteria would not change the intent of the 0.5-rem "important to safety" threshold for classification.
- The o.5 rem threshold in 10 CFR 60.2 for classifying items important to safety is intended to assure the reliability of structures, systems, or components whose failure could result in significant exposures to the public. The desired reliability is obtained by applying the design criteria in 10 CFR 60.lJl(b) and the quality assurance (QA) requirements in 10 CFR Part 60, Subpart G.
For an accident whose projected consequences exceed 0.5 rem but do not exceed the 5 rem effective (or 50 rem committed) dose equivalent accident dose criteria, the structure, system, or component the failure of which would result in the accident would be designed according to 10 CFR 60.l3l(b) and subject to Subpart G requirements. Mitigation would not be required within this dose range. However, if analyses indicate that the accident dose criteria would be exceeded, the structure, system, or component in question would not only be designed according to 10 CFR 60.lJl(b) and would be subject to Subpart G requirements, but also, engineered safety features would be applied to mitigate the accident consequences to below the accident dose criteria.
The engineered safety features applied would also be classified as "important to safety."
As indicated above, the establishment of accident dose criteria would not change the intent of the "important to safety" classification. However, the current definition of "important to safety" needs to be modified to be consistent with other changes described in this petition. The current def inition could be interpreted to mean that an accident resulting in a radiation dose of 0.5 rem or greater must be mitigated: "those engineered structures, systems, and components essential to the prevention or mitigation of an accident .*. " (10 CFR 60.2, emphasis added).
The threshold for determining the need for mitigation through the use of engineered safety features is the accident dose criteria, not the "important to safety" threshold.
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Additional modification of the current definition of "important to safety" is needed to make it consistent with the proposed accident dose criteria by incorporating the effective dose equivalent concept and the new preclosure control area boundary.
5.0 CONCLUSION
Accident dose criteria are needed to establish objective requirements for determining whether 10 CFR 60.21 has been met i.e., to determine the need for and the adequacy of structures, systems, and components provided to prevent or mitigate accidents. The current version of 10 CFR Part 60 does not contain specific accident dose criteria. The absence of such critera unnecessarily creates programmatic uncertainty associated with the design of the geologic repository operations area and
- the procurement of long lead-time items based on that design
- This uncertainty can best be eliminated through rulemaking by amending 10 CFR Part 60 to include specific accident dose criteria, and pertinent definitions to facilitate application of the criteria.
Based on the information presented above, DOE petitions the Commission to amend 10 CFR Part 60 to include accident dose criteria of 5 rem effective dose equivalent, with a limit of 50 rem on the committed dose equivalent to any organ. Such criteria are generally consistent with the Commission's dose criteria for similar accidents at other nuclear facilities and would provide adequate protection of public health and safety.
Respectfully Submitted,
- J~
J Bartlett, Director o c of Civilian Radioactive Waste Management DATED: April 19, 1990 Page ..ll,_ of ..ll,_
UNDER CURRENT 10 CFR 80 PROPOSED REVISIONS IN DOE PETITION FOR RULEMAKING
---CONTROLLED AREA BOUNDARY
- BOUNDARY AT WHICH RELEASES DURING POSTCLOSURE PERIOD ARE CALCULATED PRECLOSURE CONTROL AREA BOUNDARY
- BOUNDARY AT WHICH ACCIDENT EXPOSURES OURING PRECLOSURE PERIOD ARE CALCULATED RESTRICTED AREA BOUNDARY RESTRICTED AREA BOUNDARY
- BOUNDARY AT WHICH ACCIDENT
- BOUNDARY WITHIN WHICH ACCESS EXPOSURES DURING PRECLOSURE DURING NORMAL OPERATIONS IS PERIOD ARE CALCULATED CONTROLLED FOR PURPOSES Of
- BOUNDARY WffiilN WHICH ACCESS RADIATION PROTECTION OURING NORMAL OPERATIONS IS CONTROLLED FOR PURPOSES Of RADIATION PROTECTION Figure 1. Comparison of Current and Proposed Boundaries 0208-00370S 12/5/89