ML20029B368
| ML20029B368 | |
| Person / Time | |
|---|---|
| Issue date: | 03/01/1991 |
| From: | Moeller D NRC ADVISORY COMMITTEE ON NUCLEAR WASTE (ACNW) |
| To: | Carr K NRC COMMISSION (OCM) |
| References | |
| NACNUCLE-R-0048, NACNUCLE-R-48, NUDOCS 9103070120 | |
| Download: ML20029B368 (4) | |
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UNITED STATES -
ACNWR-0048 g
-NUCLEAR REGULATORY. COMMISSION
- t-ADVISORY COMMITTEE ON NUC!. EAR WASTE g
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WASHINGTON, D.C. M66 PDR o
March 1, 1991
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l The Honorable Kenneth M. Carr Chairman U.S. Nuclear Regulatory-Commission Washington,'DC 20555
Dear Chairman Carr:
SUBJECT COMMENTS-ON 10 CFR PART 60.113, SUBSYSTEM REQUIREMENTS In response to.a request from Commissioner James R.
Curtiss, the Advisory Committee _on Nuclear Waste has for the past severa? months examined theLsubsystem performance requirements of-10 cra Part 60, with : specific attention being directed -to the foi. lowing two i
_ quest ons:
- 1. -
If L a site meets the standards for. a high-level radioactive waste repository as promulgated by the - U. S.
Environmental-
- Protection Agency (EPA', 1985), does that ensure that.the site
>will meet the= subsystem performance requirements of the U.S.
Nuclear Regulatory Commission (NRC, 1983a) 'in 10- CFR Part 60?:
2.
If a site. meets the :NRC subsystem performance requirements, doesLthataensure that the EPA standards will be met?'
f The= answer to both-'of'these questions is1"No,"
'In the course of-our deliberations we examined a range of: issues on, this E9hject.
Through ! this; sletter,1we - share with you -our observations and recommendations.
Subsystem Performance Recuirements
'Accordine "o_-the NRC regulations, a mined geologic repository will-
'lindt the: rate 1of1 waste (radionuclide) ' release to ~ the -accessible
_ f_.
'orment-by means of an engineered barrier system'(EBS) und the; e
- setting J(natural: system). The two systems dif fer in~ their -
.ition:
to'- < isolation and-in the associated ' degree of; ance..The EBS!is expected to be the main barrier'during the or. conditions when the response of the system is most
-i tain,-and the geologic setting will. provide the major barrier w.alcases over the long term.
This approach conforms with the
-long-established NRC po'ld ;y-of providing for defense in depth.
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.Tho Honorable Kenneth M.
Carr 2
March 1, 1991 Of the three subsystem performance requirements specified in 10 CFR Part 60.113, the first two relate to the EBS, the third relates to'the geologic setting, as follows:
1.
" Containment of HLW within the waste packages will be substantially complete for a period to be determined by i.hv Commission provided that such period chall be not less than 300 years nor more than 1,000 years after permanent closure of the geologic repository...."
2.
"The release rate of any radionuclide from the engineered barrior system following the containment period shall not exceed one part in 100,000 per year of the inventory of that radionuclide calculated to be present at 1,000 years following permanent closure...."
3.
pre-waste-emplacement groundwater travel time along the fastest path of likely radionuclide travel from the disturbot, zone to the accessible environment shall be at leas; 1,000 years...."
In addition to these requirements there is a statement (10 CPR Part 60,112) that the overall system perfgntlance obiqct ive is to have the r m itory
" conform to... environmental standards for radioactivity as may have been established by the Environmental Protection Agency with respect to both anticipated processes and events and unanticipated processes and events."
The NRC regulations also include language that permits the Commission to
-allow flexibility in the application of each of its subsystem requirements,
... provided that the overall system performance objective, as it relates to anticipated processes and events, is satisfied."
Belation Between Subsystem Decruirements and thqlEA. stanclara;1g Interaction with the NRC staff has revealed that no deliberate attenpt was made to relate the NRC subsystem requirements to the I
EPA ctandards.
1.
Information developed by the NRC staff clearly tends to confirm the lack of a nexus.
For example, Table 1, Appendix A,
of the EPA standards prov. ides maximum relaare limits for a range of radionuclides anticipated to be preserA in en HLW repository.
Calculations show that, if radionuclides are annually released at a rate of one part in 100,000 of the inventory at 1,000 years (as specified in the NRC subsystem requiroments), the quantities of certain isotopes of plutonium and americium released could be much larger than the limits specified in the EPA standards (NRC, 1983b).
1
.The Honorable Kenneth M. Carr 3
March 1, 1991 2.
It is also probab,te that compliance with the.:PA standards might be accomplished without conforming to one or more of the NRC subsystem requirements.
For example, a repoultory that meets the EPA standards might very well have a groundw-ter travel time of less than 1,000 years.
3.
Commissioner Curtiss inquired also about the stringency of the NRC subsystem requirements.
The necessity of complying with two sets of regulations would appear to place an added burden on the licensee.
The stringency of the NRC requirements, however, cannot readily be evaluated against the EPA standards because (a) the NRC subsystem requirements were not based on the EPA standards and (b) a comparison of the NRC and EPA requirements needs to be site specific.
Sammary C_pmments In summary, our conclusions and observations are as follows:
1.
There is no nexus between the EPA standards and the NRC subsystem requirements.
This is not an oversight; apparently no nexus was intended.
As long as the NRC regulations include 10 CFR Part 60.112, this situation is primarily a regulatory issue, not a techr.ical issue.
It is not a matter that will compromise the protection of public health and safety.
2.
Meeting the subsystem requirements specified in the NRC regulations does not ensure compliance with the EPA standards; the converso is also true. The NRC staf f should be encouraged to continue to issue statements clarifying the subsystem requirements so that they are less subject to misinterpretation.
3.
Both the EPA standards and the NRC regul". cions include
-statements that are designed to permit flex 3aility in their application.
Implementing the flexibility, however, may be difficult particularly (as pointed out by Commissioner Curtiss, 1990) under the intense public scrutiny anticipated at the time the licensing process will be underway.
4.
It appears likely that the applicant for an HLW repository license wa l1 need to address the NRC and the EPA requirements separately.
This appears to be true not only because there seems to be no technical relation between the two sets of regulations,,,ut also because demonstration that the f acility can meet both rots of requirements appears as an inherent part of the regulations.
In our opinion, the health and safety of the public is not likely to be impaired by this situation.
We are not able to comment on the purely regulatory or legal aspects of the dual regulatory impacts of the subsystem requirements.
1
i
. Thd lionorable Kenneth H. Carr 4
March 1, 1991 We trust thoso commento will be r w 'ul.
- 2nrerely, o
bado W. Moeller Chairman Referencost (Curtiss, 1990).
Curtiss, James R., " Repository Performanco -- The Rogulatory Challengo," Papor presented at Symposium on Radioactive Wasto Repository Licensing, National Academy of Sciencos, :lational Roscarch Council, Washington, DC, September 17, 1990.
[ EPA, 1985).
U.S. Environmental Protection Agoney, " Environmental Rcdiation Protection Standards for Management and Disposal of Spent sluclear Fuel,
!!1gh-Loyal and Transurte.nic Radioactivo Waston,"
Titio 40, Part 391, Code of Podoral Regulatione, Washington, DC, 1985.
(NRC, 1983a). _ U.S.
Huoloar Regulatory Commission, hDisposal of liigh-Lovel Radioactive Wastos in Geologic Repositorios," Title 10, Part 60, Codo of Federal Regulations, Washington, DC, 1982.
[HRC, 1983b).
U.S. Nucicar Regulatory Commission, " Staff Analysis of Public Comments on Proposed Rule 10 CFR Part 60, ' Disposal of High-Level Radioactive Wastos in Geologic Repositories,'"
Report NUREG-0804, Washington, DC, December 1983.
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