ML20217H728
| ML20217H728 | |
| Person / Time | |
|---|---|
| Issue date: | 10/11/1997 |
| From: | Jim Hickey NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Mendonca M NRC (Affiliation Not Assigned) |
| Shared Package | |
| ML20217H730 | List: |
| References | |
| REF-WM-3 DSI-24, NUDOCS 9710170043 | |
| Download: ML20217H728 (4) | |
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, October 11, 1997 MEM,ORANDUM TO: Marvin Mendonca, Acting Director
- Non Power Reactors and Decommissioning Project Directorate Division of Reactor Program Management Office of Nuclear Reactor Regulation FROM: John W. N. Hickey, Chief [0RIGINALSIGNEDBY]
Low-Level Waste and Decommissioning Projects Branch Division of Waste Management Office of Nuclear Material Safety and Safeguards
SUBJECT:
SUPPORT FOR RESPONSE TO COMMISSION REGARDING DSI-24 POWER REACTOR DECOMMISSIONING Attached is the Division of Waste Management response to your request for support on DSI-24. Please contact David N. Fauver,415-6625 if you have questions or comments.
Attachment:
As stated TICKET: $
DISTRIBUTION: Central File LLDP r/f NMSS r/f PUBLIC RJohnson 3 TCJohnson h (RNIlson To receive a copy of this document in small box on "OFC:" line enter. "C" = Copy without attachment / enclosure; "E" = Copy with atta hment/ enclosure:"N" = No copy Path & File Name: S:\DWM\LLDP\DNF\DSI-24.wpd g
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NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20066 4001
% ,,,,, # October 11, 1997 MEMORANDUM TO: Marvin Mendonca, Acting Director Non-Power Reactors and Decommissioning Project Directorate Division of Reactor Program Management Office of Nuclear Reactor Regulation -
FROM: John W. N. Hickey, Chief Low-Level Waste and Decotafnissioning f, [f Projects Branch Division of Waste Management Office of Nuclear Material Safety and Safeguards
SUBJECT:
SUPPORT FOR RESPONSE TO COMMISSION REGARDING DSI-24 POWER REACTOR DECOMMISSIONING Attached is the Division of Waste Management response to your request for support on DSI-24. Please contact David N. Fauver,415-6625 if you have questions or comments.
Attachment:
As stated
SUPPORT TO NRR ON RESPONSE TO COMMISSION REGARDING DSI 24, POWER
, REACTOR DECOMMISSIONING Beginning in 1990, the staff began an effort to upgrade NRC's guidance on acceptable methods for performing surveys to demonstrate that a site meets NRC's decommissioning criteria (finti surveys). This effort was a part of the NMSS Site Decommissioning Management Plan. Draft NUREG/CR-5849, ' Manual for Conducting Radiological Surveys in Support of License Termination," was published in June 1992. NUREG/CR 5849 was used as the basis for developing the final survey plans for the Shoreham and Fort St. Vrain power plants. These final survey plans were required to be submitted, and approved t,y NRC.
NUREG/CR-5849 served to significantly upgrade the consistency and quality of the final survey plans submitted by licensees. In 1994, after reviewing comments on the draft NUREG, the staff considered revising the document and issuing it as final. However, at that time N Environmental Protection Agency, in cooperation with NRC, the Department of Energy, and the Department of Defense, initiated an effort to develop the " Multi-Agency Radiation Survey a,',d Site Investigation Manual" (MARSSIM). The MARSSIM's purpose was to updata final survey guidance, considering the requirements of NRC's (and EPA's) then draft decommissioning rules. The staff decided not to finalize NUREG/CR 5849, but to instead participate in the development of MARGSIM with the intent of having MARSSIM supersede NUREG/CR-5849 when completed. The MARSSIM was published as a draft for public comment in December 1996. Comments are currently under review by the MARSSIM committee. The document is expected to published as final in early 1998. The staff intends to endorse MARSSIM as the primary guidance document for final surveys by referencing it in the regulatory guide that is currently being developed to implement the final rule on " Radiological Criteria for License Termination," published July 21,1997 (62 EB 39058).
The MARSSIM method for survey design should result in a reduction in the number of " fixed" messurements required during the final survey of decommissioning power reactors, as ccmpared to NUREG/CR-5849. This is primarily due to the difference in the method for addressing small areas of elevated contamination (hot-spots). Because the License Termination rule is dose-based, MARRSIM was abie to implement a dose-based approach to hot-spot surveys. This method gives credit for the fact that the instruments used to perform
' scan" surveys of building surfaces contaminmd with fi sion and activation products have detection sensitivities that should be well below the surface contamination limits anticipated for .
the License Termination rule. The reduction in fixed measurements may be as much as a factor of 3-4 in heavily contaminated areas compared to NUREG/CR-5849.
There are other differences between NUREG/CR-5849 and MARSSIM such as the use of non-parametric statistics and the application of the Data Quality Objective (DQO) process. The DQO process allows licensees to select data confidence levels that are commensurate with risk and cost. Decreasing the required confidence level results in a decreased sample size.
However, the increase in flexibility allowed in MARSSIM comes at the cost of greater complexity, which may result it, the survey planning process being somewhat more difficult.
Any increase in the effort required at 2.s planning stage will offset some of the gains resulting from decreased sample size. The extent of this increased effort is not known, but should be relatively low.
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The staff has also been streamlining its approach for ensuring the accuracy and representativeness of the final survey data for reactor, and materials, licensees. For the decommissioning of the Shoreham reactor, the staff used a contractor to perform a radiological assessment when the facility was ready to be released. The cost of the contractor support, which was billed to the licensee, was about $800,000. The staff considered this cost to be too high and modified the approach during the decommissioning of the Fort St. Vrain reactor. At Fort St. Vrain, NRC conducted inspections of the licensees' final survey program, while the survey was in progress. The inspections focused or, the program's quality assurance, operating procedures, training, technical bases, and data management. The number of confirmatory measurements conducted by the contractor was significantly reduced, but some contractor support was shifted to provide expert technical assistance to NRC inspectors in reviewing the program. The contractor cost for Fort St. Vrain was reduced to about $200,000, even though the number of measurements made by the licensee were greater, in addition to the reduction in cost, a significant advantage to the streamlined approach was that the licansee and NRC had resolved all major problems and issues well before the project was ended and the final survey report was issued. This provided both the licensee and NRC confidence that there would not be delays at the end of the project as could be the case if problems were identified by confirmatory surveys performed at the end of the project. Most importantly, the staff's confidence levelin the quality and accuracy of the final survey data at Fort St. Vrain was as high, or higher, than that gained through the "end of project" survey performed at Shoreham.
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