ML20151P335
| ML20151P335 | |
| Person / Time | |
|---|---|
| Issue date: | 08/03/1988 |
| From: | Browning R NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Morris B NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| References | |
| REF-WM-1 NUDOCS 8808090321 | |
| Download: ML20151P335 (7) | |
Text
e o
AUG 3 1988 TABLE S-3/ MEMORANDUM FOR:
Bill M. Morris, Director Division of Regulatory Application, RES FROM:
Robert E. Browning, Director Division of High-Level Waste Management, HMSS
SUBJECT:
COMMENTS ON DRAFT REVISIONS TO TABLE S-3 PROPOSED RULE In response to your memorandum dated June 13, 1988, we have reviewed the subject draft revisions to Table S-3.
Our comments focus on the high-level waste aspects of the proposed rule. A summary of our major comments follows:
In general, we support the approach used to estimate environmental impacts from spent fuel disposal, i.e., basing the estimates on permissible releases from a repository engineered barrier system.
However, the technical support for the proposed revisions appears to be internally inconsistent.
One example of such an apparent inconsistency involves estimates of the impacts of spent fuel disposal. An estimate of radionuclide release is provided for Table S-3 by calculating permissible releases from the engineered barriers of a repository.
However, Appendix B ignores these releases in estimating the doses that might result.
Instead, Appendix B assumes that only a few of the most mobile radionuclides (C-14, Tc-99 and I-129) will actually be released to the environment. Rather than attempting to evaluate the potential health effects of either release assumption, it would be more apprcpriate to refer to the EPA'shigh-levelwastestandards(40CFRPagt191). These standards would limit potential health effects to 3.5 X 10~ fatal cancers per year per RRY of spent fuel disposal (see 50 FR 38067). Although the EPA standards were remanded by a court decision, the health effects basis for the standard is not expected to change when the standards are reissued (see transcripts of EPA staff presentation to ACNW on July 22,1988.)
Detailed comments are provided in Enclosure 1.
should be directed to T. No (Review Coordinator) Questions on these commentsX20541 X20426 (HLOB), or R. MacDougall X23401 (HLSE) of my Division.
I Robert E. Browning, Director Division of High-Level Waste Management, HMSS
Enclosure:
Detailed Comments on Draft Amendments NOTE: SEE DISTRIBUTION NEXT PAGE i
PDC g/
a TABLE S-3/
2-k8 DISTRIBUTION Central Files REBrowning, HLWM BJYoungblood, HLWM RLBallard, HLTR J0 Bunting, HLSE JLinehan, HLOB HLTR r/f NMSS r/f TMo, HLTR DBrooks, HLTR S.P.Turel, RES
1 i
l l
1 Ngp
'f,
- SEE PREVIOUS CONCURRENCE:
'HLSE i
0FC :
HLTR*
HLTR*
HLTR*
- HLOB*
HLOB* (:
LO$g// / :
.....:....._______:.......___.:__...._____.:.______.....________....y.
.___.___,,u___
y NAME :
TMo/cj
- DBrooks
- RBallard
- DFehringer :SCoplan
__._____ A. ougall an
- RilaW DATE : 88/08/
- 88/08/
- 88/08/
- 88/08/
- 88/08/
- 88/08/,j)
- 88/08/
u
..1%ed) AM 0FC :HLSE I
_f.,__:..........__:.....___....:.____........:...._______:.____.....
NAME :JBu ing
- 88/08/,jy
o TABLE S-3/
-2_
Detailed comments are provided in Enclosure 1.
Mo (Review Coordinator) Questions on these commentsX20541 should be directed to T X20426 (HLOB), or R. Ma oucall X23401 (HLSE) of my Division.
Robert E. Browning, Director Division of High-Level Waste Management, NMSS
Enclosure:
Detailed Comments on Draf t Amendments DISTRIBUTION Central Files REBrowning, HLWM BJYoungblood, HLWM RLBallard, HLTR J0 Bunting, HLSE JLinehan, HLOB HLTR r/f itMSS r/f Tito, HLTR DBrooks, HLTR S.P.Turel, RES
- 0. Lynch, NRR W. Thompson, IMNS PDR & LPDR LSS RlicDougall, HLSE DFehringer, HLSE DA /A ONS1 06 vei)~
0FC
- HLTR
- HLT
- HL
- L
...;.__:.... ' A.:...
,.........:. p. y 4_..::..,.....c__.:Q..SE g
- J4 HLOB
...p HAME :TMo V
- DBroo
- RBallard
- DFefiringer
- SCoplan
- JLinehan
- RitacD gall
___..:..___......:.........:...._______ :....._______:........._..:....___.....:.f. ___..
DATE :88/08/l
- 88/08/)
- 88/08//
- 88/08//
- 88/08//
- 88/08/
- 4. 8/08/
hT c e_ c ',l.
0FC tILSE
- HLSE
.....:.._,./.J....:........____:.......____:....____....:..........._:............:.........
NAME :JB nting
- REBrowning
_....f._
DAT[:88/0
- 88/08/
~
ENCLOSURE 1 Detailed Comments on Draft Amendments to Table S-3 Page 8, lines 17 & 18, Text This text states that the location of an HLW repository will be at Yucca Mountain, Nevada. The text should be clarified to reflect that this site has only been required to be characterized, and has not yet been found, on the basis of characterization, to be suitable for repository development.
It should also be noted that the 1987 amendments to the Waste Policy Act leave open the possibility that another site might be selected.
Page 9, line 5, Text Suggested clarification:
... spent fuel (33,000 mwd /MTU).
It, also,..."
Page 11, lines 20 & 21, Text Suggested clarification:
... values for Tc-99 which are being added to Table S-3 through this rulemaking (except those for releases from a repository) are based..."
Page 19, Fission and Activation Products (Subheading)
The value (3Ci/yr) attributed to repository releases of fission and activation products from a repository into groundwgter appears to be in error for two reasons.
This figure represents 10" of the inventory per metric ton of 10-year-old spent fuel.
The corresponding figure per reference reactor Lear (RRY) would be 105/yr.
However, the release rate criterion of Part bu references the spent fuel inventory at 1,000 years, rather than the 10 year inventory.
If the 1,000 year inve6 tory were used, the release rate would be 8 E-3 Ci/yr for fission and activation products or 6 E-1 C1/yr for actinides, fission and activation products.
I
Page 45, line 10, Text Suggested clarification:
"The NRC regulations for repository disposal of high-level radioactive waste (10 CFR Part 60) limit the releases of radio-active material from the engineered barriers of a repository. The basic requirements are that there should be no leakage from the waste packages in the first 300 to 1000 years and that the annual releases from the engineered barrier system thereafter should not exceed one part in 100,000 of the total inventory of each radionuclide calculated to be present 1,000 years following permanent closure of the repository.
The values in Table S-3 have been revised to reflect the maximum allowable releases from the engineered barriers of a repository. These values are conservative because no credit is taken for chemical or physical retardation and for additional decay of radionuclides during transport through groundwater within the controlled zcne prior to release to the accessible environment.
Page 46, lines 2-6, Text Suggested clarification: "... including higher burnup of the fuel.
One of the greatest..
10 to 100.
Significant uncertainties are also associated with the estimates..."
Page 46, line 9, Text Suggested clarification:
... maximum levels permitted for releases fro-the engineered barriers of a repository by NRC regulations..."
Page 53, Liquids (Heading), Tc-99 (Subheading)
This line of Table S-3A combines a total release value for Tc-99 (0.22 Ci/RRY from enrichment) with a release rate (0.005 Ci/yr/RRY) for spent fuel disposal. The values should be in consistent units, or they should be listed separately.
Page 54, paragraph beginning line 7, Text This discussion of the Waste Confidence Rulemaking seems irrelevant and should be deleted unless its pertinence is explicitly stated.
2
Page 55, paragraph beginning line 21, Text This discussion seems to be saying that the radiological impacts from gaseous releases are much greater than potential impacts of releases via l
l liquid pathways. While this may be so for storage prior to disposal, the text should make clear that it may not be so for evaluating the impacts following repository disposal of spent fuel.
Page 55, line 11, Text Suggested clarification:
In 1983 the NRC published its final high-level waste regulation, 10 CFR Part 60. Two of the requirements of that rule permit an easy, albeit conservative, assessment of radionuclide releases.
These are that the waste package containme'it remain substantially complete for a period of 300 to 1000 years and that the release rate from the engineered barriers after the containment period not exceed one part in 100,000 per year of the total inventory of each radionuclide calculated to be present 1,000 years following permanent closure of the repository.
The estimates for Table S-3 were based on compliance with these requirements.
Page 55, line 24, Text Suggested clarification:
This text states that releases of tritium and carbon are assumed to be controlled to levels allowed by the EPA standards in 40 CFR 190.
However, tritium and carbon are not mentioned in Part 190.
Rather, it appears that total release (after 10 years of decay) was assumed.
If so, the explanatory text needs to be clarified.
Page 64, second paragraph, Text This is confusing since it mixes discussions of both the old Table S-3 and the revised table that would replace it.
Since this discussion is intended to be CFR text accompanying the new Table S-3, only the assumr " is relevant to the new table should be included.
It also is not clear. m the 50% Kr-85, 10% C-14, and 1% H-3 and I-129 figures entered into tiie calculations of the revised Table S-3 impacts.
Finally, the text should provide the reference or other basis for the statements about potential for migration of different radionuclides from a repository.
Page 65, line 5, Text Suggested clarification:
...the full inventory (tritium and carbon-14) or the maximum that would be allowed under the EPA uranium fuel cycle regulation (40 CFR 190)."
3
a p
Page 91, line 21, 22, Text Suggested clarification:
...will have engineered features that are intended to enhance isolation of waste."
Page 100, lines 5 & 6, Text Suggested clarification: Spent fuel will also contain the volatile fission products.
Page 101, lines 1-12, Text Suggested clarification:
"A repository will be licensed only in an area where the probability that a natural event would disturb the repository is sufficiently low and the area is sufficiently remote fron identified natural resources to minimize the probability that people would inadvertently disturb the repository. The Commission would also require reasonable assurance that in the event of water infiltration into the repository, it would take a long time for the leached radionuclides to be transported to the biosphere by groundwater movement and that in this period of time, most radioactive material will have been reduced to acceptable levels due to radicactive decay and retardation on soil / rock surfaces."
Page 102, paragraphs 1 and 2, Text Clarify the first two paragraphs with respect to whether spent fuel is more hazardous than uranium for 10,000 years or for 100,000 years.
Page 103, lines 9-11. Text The 10-5 per year release rate c. iterion derives from 10 CFR 60, not the EPA standards.
Page 103, line 15, Text Suggested clarification:
... sorption is assumed to be very low..." for Tc-99.
Page 103, lines 16-18, Text The text should support the assertion that the potential dose from Tc-99 is trivial compared to doses from Rn-222, C-14 and I-129.
l 4
i
.