ML20126E602
| ML20126E602 | |
| Person / Time | |
|---|---|
| Issue date: | 12/22/1992 |
| From: | Moeller D NRC ADVISORY COMMITTEE ON NUCLEAR WASTE (ACNW) |
| To: | Bernero R NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| NACNUCLE-R-0085, NACNUCLE-R-85, NUDOCS 9212290215 | |
| Download: ML20126E602 (3) | |
Text
[s..,% ),
UNITED S1 ATES e
NUCLEAR REGULATORY COMMISSION ACNWR-0085
,e 0>
i ADVISORY COMMartEE ON NUCLE AR WASTE Io,
'f WASHINGTON. D C. 20%5 NN
%.u f December 22, 1992
!!r. Robert M. Bernero, Director of fico of fluclear Material Safety and Safeguards U.S.
liuclear Regulatory commission Washington, D.C.
20555
Dear Mr. Bernoro:
SUDJECT:
IMPACT OF uoNG-RAliGE CLIMATE CHANGE IN Tile SOUTHERN GREAT BASIN The Advisory Committoo on liuclear Wasto ( ACNW) hold a Working Group mooting on the Impact of Long-Range Climate Chango in the Southern Great Basin on November 18, 1992.
The ACNW also discussed this subject during its 48th and 49th mootings on November 19 and 20, 1992 and December 17 and 18, 1992, respectively.
The objective of the Working Group mooting was to exploro the state of knowledge of the potential impact of long-rango climato change on the ariticipated performance of the proposed high-lovel radioactive wanto (HLW) repository at Yucca Mountain, Nevada.
The principal questions of concern to the Committee at this mooting woro:
What is the significance of potential climate change in the Southern Great Basin to the integrity of the proposed HLW repository at Yucca Mountain?
What are the nature and quality of models that will b., used e
for predicting the climato for the next 10,000 year::; at Yucca Mountain?
Ato data and methods available to test and qualify the models?
e Participating in the Working Group were nine specialists in climato change from the U.S.
Geological Survey, the National Geophysical Data Contor of the National Oceanic and Atmospheric Administration, the National Centor for Atmospheric Research, the Canter for Nucionr Waste Regulatory Analysos, and consultants to the U.S.
Department of Enorgy (DOE) and tho'Stato of Nevada.
Presentations were nado on:
(1) the impact of climato change on the repository; (2) paleoclimatological and paleohydrological methodologies, DOE Study Plans to conduct the required investigations, and preliminary-results from the Yucca Mountain region; (3) the role and status of paleoclimatic and palcohydrologic data; and (4) the basis, rolo, and status of global climato models and regional (southwestern U.S.) climate models, b
h hE p
R-ooos
w Mr. Robert M. Bernero 2
December 22, 1992 The mooting provided an excellent opportunity for dialogue among climatologists, geologists, geochemists, hydrologists, and modelers and gave the ACHW a useful view of the climatology studios of the Yucca Mountain region currently underway by the DOE and its contractors and consultants.
Several specific items came to our attention during the Working Group mooting that we believe are of suf ficient importance and interest that they should be communicated to you.
These includo:
1.
The current palcohydrologic and paleoclimatic studios at Yucca Mountain sorvo as a baselinc for forecasting climate and for testing climatic models by hindcasting.
These investigations will not be completed until late in this decado, at the earliest, thereby impeding timely analysis of the potential impact of climato change on the integrity of the proposed HLW sito.
2.
A critical element in determining the effect of climato change is the rate of infiltration (fracture and matrix permeability) through the vadoso zono at Yucca Mountain.
The relationship between precip tation and infiltration flux is an essential j
paramotor in relating predicted climatic conditions to the impact on the proposed repository.
The definition of this paramoter, its variability, and the roleted uncertainties should be given high priority.
3 Preliminary estimatos of the impact of climato change over the next 10,000 years at Yucca Mountain indicato that the proposed repository will romain above the water table.
However, those predictions are based on climatic and hydrologic models that are preliminary in nature and are supported by an inadequato data base. Additional data acquisition and analytical studies are warranted. Sensitivity studios should be conducted to determine the degree of uncertainty that can be accepted in those data and those models without invalidating conclusions regarding the likely impact of climate change on the repository.
4.
The meeting revea}cd an apparent lack of intra-and inter-communication among the several disciplinos involved in climate study (e.g., hydrology and climate modeling).
While individual researchers displayed.
a high degree of understanding of their own scienco and mission, they also displayed a lack of awareness of important inforn.ation that could have come from otner investigators.
5.
Climatology is a significant discipline that needs to be represented within the areas of staff expertise available to the Commission.
There is a need to monitor the Yucca Mountain l
climate change program and especially the climato modeling efforts of the DOE contractors.
b.
Mr. Robert M. Bornero 3
December 22, 1992 6.
Ilot all current DOE programs aimed at investigating climato change at Yucca Mountain are being performed under the study plan submitted to the fiRC.
Additional items of potential interest and further elaboration of the above points are availab e from the transcripts of the Working Group meeting and the discussions during the latter half of the first day of the 48th meeting of the ACNW.
Sincerely, Dade W. Moeller Chairman
'ter- - - -
m a
m T