ML20198H848

Generic Technical Position on Design Info Needs in Site Characterization Plan

ML20198H848
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Issue date:	12/31/1985
From:	NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
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ML20198H833	List: ML20198H828 ML20198H844 ML20198H848
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l-U.S. NUCLEAR REGULATORY COMMISSION GENERIC TECHNICAL POSITION

ON l DESIGN INFORMATION NEEDS IN THE SITE CHARACTERIZATION PLAN l

ENGINEERING BRANCH.

i DIVISION OF WASTE MANAGEMENT December 1985 i

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i Table of Contents PAGE

1.0 INTRODUCTION

3 2.0 TECHNICAL POSITION 4 2.1 Types and Level of Detail of Design Information 4 for the Site Characterization Plan (SCP) 3.0 DISCUSSION OF DESIGN INFORMATION NEEDS FOR THE SCP 4 3.1 General Design Criteria for the Geologic 5 Repository Operations Area 3.2 Additional Desigr. Criteria for Surface Facilities 5 in the Geologic Repository Operations Area 3.3 Additional Design Criteria for the 6 Underground Facility 3.4 Design of Seals for Shafts and Boreholes 6 3.5 Barriers Important to Waste Isolation 6 3.6 Alternative Design Concepts 7 3.7 Design Information to Support the Performance Assessments 7 3.8 Uncertainty 8 3.9 Quality Assurance 8 4.0

SUMMARY

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5.0 REFERENCES

10 Figure 1 Basic NRC Health and Safety Resocnsibilities in 10a Geologic Repository Licensing APPENDICES A. Public Law and Regulatory Framework 11 B. Definitions 13

3 GENERIC TECHNICAL POSITION ON DESIGN INFORMATION NEEDS IN THE SITE CHARACTERIZATION PLAN

1.0 INTRODUCTION

The Nuclear Waste Policy Act of 1982 (NWPA) and 10 CFR 60 require that the Department of Energy (00E) submit Site Characterization Plans (SCP) to the Nuclear Regulatory Commission (NRC). In accordance with Section 113(b) of the NWPA, the DOE must submit to the NRC, along with its plan for site characterization, "a conceptual repository design that takes into account likely site-specific requirements." Information should be in sufficient detail to allow an assessment of the site characterization program in connection with the' submittal of Site Characterization Plans. Regulatory Guide 4.17 (Ref. 1),

entitled " Standard Format and Content of Site Characterization Reports for High-level Waste Geologic Repositories," provides supplemental guidance on the format and content of the SCP.

This Generic Technical Position (GTP) addresses the type and the level of detail of design information that needs to be included in the SCP. This is intended to ensure that the Site Characterization Plan will include sufficient design information for the NRC to assess the completeness and adequacy of the site characterization program for the proposed geologic repository. Some of the

" conceptual designs" or " design' studies", submitted to the NRC have not adequately addressed the performance objectives of 10 CFR 60.111-113 (see figure 1). The NRC has reviewed the Site Characterization Report (SCR) for the Basalt Waste Isolation Project (1982) and has prepared a Draft Site Characterization Analysis (SCA) (Ref. 2) of the SCR for the Basalt Waste Isolation Project (1983). The SCA contains guidance on the type of design information needed by the NRC in the SCP.

The NRC recogn nes that design information needs will vary from site to site.

However, some design information needs are generic (i.e. common to all sites).

This GTP contains gijidance which the NRC has developed for all candidate sites in the various media. More detailed site specific guidance will be provided, in accordance with the agreement entitled " Procedural Agreement Between the U.S. Nuclear Regulatory Commission and the U.S. Department of Energy Identifying Guiding Principles for Interface During Site Investigation and Site Characterization" (Morgan-Davis Agreement), (Ref. 3) and the " Agreement Between the Department of Energy's Office of Geologic Repositories Projects (BWIP,NNWSI,SRP,CRP) and the Nuclear Regulatory Commission's Division of Waste Management During the Site Investigation and Characterization Programs and

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l Prior to the Submittal of an Application for Authorization to Construct a Repository" (Ref. 4).

This Generic Technical Position is organized as follows: Section 2 addresses the type and level of detail of design information needs. Section 3 discusses the NRC design information needs, based on 10 CFR 60. Section 4 summarizes this Generic Technical Position. Finally, Appendix A provides the statutory requirements for the conceptual design at the time of the SCP submittal.

2.0 TECHNICAL POSITION 2.1 Types and Level of Detail of Design Information for the SCP Geologic Repository Design Information should be provided in sufficient detail to allow the NRC to make a determination about the completeness and relevancy of planned site characterization activities. The type of information needed by the NRC includes aspects of the design and the site that contribute to meeting

'tne performance objectives and design criteria of 10 CFR 60 (see Figure 1).

Specifically, the SCP submitted should include the following: a) the bases for the design, b) information detailed enough to permit an evaluation of whether the types and quantities of testing and analyses to be performed during site characterization will be adequate; and (c) information detailed enough to permit an evaluation of whether the suitability of the site will be compromised by the facilities that will be constructed for site characterization.

Additionally, the information should be sufficient to enable the NRC to evaluate whether a repository conforming to the conceptual design could be developed in accordance with 10 CFR 60, if data obtained during site characterization conform to the bases for the design.

3.0 DISCUSSION OF DESIGN INFORMATION NEEDS FOR THE SCP The following sections identify what types of design information the NRC needs when the 00E submits the SCP to satisfy the technical position stated above.

This discussion addresses design information which will require unique site specific characterization information needs. Where standard designs which have been used successfully for other nuclear facilities (e.g. waste handling for surface facilities) are to be used, details of the design need not be submitted. However, generalized plans sufficient to assure the feasibility of site adaptation of these facilities should be submitted. Identification of design issues which will require site specific characterization is needed to evaluate testing needs at the time of SCP submittal. All of the design

5 information to establish site characterization needs should be referenced and made available to the NRC at or before the time the SCP is submitted.

3.1 General Design Criteria for the Geologic Repository Operation Area 3.1.1 " Radiological Protection" 10 CFR 60.131.a The DOE should state, in general, how the geologic repository design will, during the operational phase, maintain radiation exposures within the limits required in 10 CFR 20. This statement should include plans to incorporate "as low as reasonably achievable" (ALARA) criteria for occupational exposure into the overall design criteria. The DOE should identify specific site characterization activities designed to generate data that will reduce the uncertainty associated with meeting the 10 CFR 20 requirements.

3.1.2 " Structures, Systems, and Components Important to Safety" 10 CFR 60.131.b The first step in the analysis of the various systems, structures and components of the geologic repository should be to analyze which of these could result in a release, if they fail te perform their intended function, of a dose commitment of 0.5 rem or greater, at or beyond the nearest boundary of the unrestricted area, at any time until the completion of permanent closure (i.e.,

important to safety, as defined in 10 CFR 60.2).

The DOE should identify and present the bases for which structures, systems and components of the geologic repository have been determined to be important to safety in the SCP. If an item is considered important to safety, then an assessment should be conducted to establish what site characterization data are needed to properly design the item considering 10 CFR 60.131.b requirements, to avoid or mitigate off-site radionuclide releases. Items that are important to safety must be covered by a quality assurance program as required by 10 CFR 60.151.

3.2 Additional Design Criteria for Surface Facilities in the Geologic Repository Operations Area (10 CFR 60.132)

A general description and layout of the waste handling facilities (surface) should be presented along with the procedure for handling and retrieval of wastes. A description of foundation investigation plans for surface facilities should also be presented. Site characterization information needs for the following items should be integrated into the SCP for the surface facilities:

facilities for receipt and retrieval of waste; surface facility ventilation; radiation control and monitoring; and waste treatment facilities. I l

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6 3.3 Additional Design Criteria for the Underground Facility (10 CFR 60,133)

The SCP should include a general description and layout, and rationale for the design of the underground facility and shafts. The design details presented in the SCP should include the proposed location of shafts, the depth of host rock, the geometry and orientations of underground openings and the relationship between the test facility (including shafts) and the geologic repository.

Information concerning the materials that comprise the engineered barrier system should be presented as well as a description of their properties, function and a rationale for their use. In addition, a discussion of how the engineered barriers will be installed should be included in the SCP. This is needed to assure that the installation of the engineered barriers will not affect the integrity of the site. A discussion of possible disruptive events (e.g., water inflow, earthquake, rock burst etc.) should be included as well as their effect on geologic repository operations and integrity. This should enable the staff to evaluate whether the planned investigation will be sufficient to support assessments of repository performance in the presence of unanticipated processes and events. The SCP should address the following items as articulated in 10 CFR 60.133; flexibility of design, retrieval of waste, control of water and gas, stability of underground openings, rock support systems, rock excavation, underground facility ventilation, and thermal loads.

A discussion of how the design considers the above items should also be f

included in the SCP.

3.4 Design of Seals for Shafts 'and Boreholes (10 CFR 60,134)

The SCP should also include a description of borehole and shaft seal designs.

The seal design should define and justify the performance requirements.

Boreholes and shaft seal materials and placement methods should be discussed.

A distinction should be made between short-term and long-term seals in the SCP.

It is especially important to describe plans for sealing the exploratory shafts and to provide assurance that site characterization activities will not compromise the site or design. For additional guidance on borehole and shaft sealing, the NRC has prepared the document entitled, "NRC Ger.eric Technical Position on Borehole and Shaft Sealing of High-level Waste Repositories" (Ref.

5).

3.5 Barriers Important to Waste Isolation The SCP should include a description of barriers important to waste isolation which must be designed to allow the repository to meet the performance objective of 10 CFR 60.113, (a) General Provisions - (1) Engineered Barrier System. This section requires that containment within the waste package be substantially complete for a period deternined by the Commi3sion, but not less

7 than 300 years nor more than 1,000 years after permanent closure, and that, unless otherwise apr. roved or specified by the Coninission, the release rate of radionuclides from the engineered barrier system following the containment period shall not exceed one part in 100,000 per year of the inventory present at 1,000 years of any radionuclide released at a rate greater than 0.1% of the calculated total release rate limit. The SCP should also provide preliminary numerical values which, subject to Commission approval, DOE contemplates will be established as the performance requirements of the engineered barrier system components and the rationale for their selection (i.e., specify the provisional allocation of performance of individual components of the engineered barrier systems that are necessary to assure that the geologic repository, as a whole, meets overe.Il performance requirements). The specification of such preliminary numerical performance requirements for the engineered barrier system components is nacessary to evaluate whether the planned testing and characterization of '

these cooponents will be adequate. Thus, identification of preliminary ,

performance requirements is an essential foundation which should underlie a '

sound site characterization program. Additional guidance on the methodology for dr.termining compliance with 10 CFR 60, for both the natural and engineered ,

syste.n, is provided in the NRC Generic Technical Position on Licensing Assessment Methodology for High-Level Waste Geologic Repository (Ref. 6).

Ite'os that are considered to be Important to Waste Isolation must be coverad by a quality assurance program as required by 10 CFR 60.151.

3.6 Alternative Design Concepts Alternative design concepts for the geologic repository operations area should also be identified by the DOE which allow for: (a) uncertainties in site parameters; (b) site properties which may vary within the developed area; (c)  :

local unacceptable conditions which could reasonably be expected to be encountered; (d) flexibility to make trade-offs between sub-system components; and (e) the interrelationship between system / components, to determine the performance of the overall geologic repository facility or components of the ,

system. The rationale for the preferred and alternative design concepts should also be presented. Documents supporting the design concepts should also be referenced in the SCP. L 3.7 Design Information to Support the Performance Assessments I A comprehensive geologic repository operations area design should be provided  !

by the DOE in sufficient detail to help establish hcw much and what types of information will be needed to support the performance assessments, as required i in 10 CFR 60.

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8 Any planned use of numerical models, either to validate the codes or to guide the testing program, should be described in the SCP. The names and stage of development of specific computer codes that are being used should be provided in the SCP.

l l 3.8 Uncertainty l The oesign presented in the SCP should identify and allow for uncertainties in the site parameters, design parameters, and numerical models. These i

uncertainties can influence the reliability of and confidence in the performance of a system component. For example, the waste package design must assume certain stress levels as well as groundwater (or brine) flow rates (what uncertainties exist in. those assumed values?). That is, the design must allow for a reasonable bounding of a range of conditions where there is uncertainty.

As stated in the Draft Site Characterization Analysis for BWIP (Ref. 2),

preliminary sensitivity analyses should be performed to evaluate pirametric changes on system or component performance. Plans for bounding uesign '

parameters and for performing preliminary sensitivity analyses should be identified in the SCP.

3.9 Quality Assurance (10 CFR 60.152) i i The DOE shall describe in tne SCP the program designed to meet the Quality Assurance (QA) requirements of 10 CFR 60. General staff guidance on determining the scope and content of an acceptable QA program is addressed in the document entitled "NRC Review Plan: Quality Assurance Programs for Site Characterization of High level Nuclear Waste Repositories" (Ref.7).

4.0

SUMMARY

The purpose of this technical position is to identify the type and the level of cetail of design information which should be included in the SCP. A discussion of the design information that is needed by the NRC to evaluate the adequacy and ccmpleteness of the Site Characterization Plans with respect to investigative activities of a candidate site for a high level waste geologic repository has been included in this GTP.

Design informaticn that is required in the SCP may vary from site to site.

l This technical position identifies generic guidance that the NRC has developed i to date for all candidate sites in the various media. More detailed site specific guidance will be provided to the DOE in accordance with the agreements

entitled " Procedural Agreement Between the U.S. Nuclear Regulatory Commission i

and the U.S. Department of Energy Identifying Guiding Principles for Interface l

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~During Site Investigation and Site Characterization" (Morgan-Davis Agreement),

(Ref. 3) and the " Agreement Between the Department of Energy's Office of .

Geologic Repositories Projects (BWIP,NNWSI,SRP,CRP) and the Nuclear Regulatory Commission's Division of Waste Management During the Site Investigation and Characterization Programs and Prior to the Submittal of an Application for Authorization to Construct a Repository" (Ref. 4)

Design information needs at the license application stage will be much more detailed than those required at the time of the SCP submittal. The information needed at the time of a license application will be discussed in a future technical position.

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5.0 REFERENCES

1. Standard Format and Content of Site Characterization Reports for High level Waste Geologic Repositories, NRC Regulatory Guide 4.17, July 1982.

2. Draft Site Characterization Analysis for the Site Characterization ReDort for the Basalt Waste Isolation Project NUREG-0960, March 1983.

3. Procedural Agreement Between the U.S. Nuclear Regulatory Corraission and the U.S. Departrent of Energy Identifying Guiding Principles for Interface During Site Investigation and Site Characterization (Morgan-Davis Agreement), June 1983.

4. Agreement Between the Department of Energy's Office of Geologic Repositories Projects (BWIP,NNWSI,SRP,CRP) and the Nuclear Regulatory Commission's Division of Waste Management During the Site Investigation and Characterization Programs and Prior to the Submittal of an Application for Authorization to Construct a Repository", September 1984.

5. NRC Generic Technical Position on Borehole and Shaf t Sealing of High-level Nuclear Waste Repositories, draft issued for public comment, December 1983.

6. NRC Generic Technical Position on Licensing Assessment Methodology for High Level Waste Geologic Repository, draft issued for public comment, July 1984

7. NRC Review Plan: Quality Assurance Programs for Site Characterization of High Level Nuclear Waste Repositories, June 1984 1

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FIOURE 1 DA5!C_MflCJfEALTH AND_$METY RE32QNSipJk1TIL8JM_GEDLOGICBEOSITORY LICENSING (Related Primerify la Designi AREAS OF RESPONSIBILITIES PRE-CLOSURE PERIOD POST. CLOSURE PERIOD OPERATf0N. RETRIEVAL CONTAINMENT /ISOt.ATION Radiological Safety _ 10 CFR 80/ EPA STD."

Geologic Repository Operations Area e Release to acceselble environment shelf be less

- Restricted Aree  ; then the Nmits specified Normal Operation 4 -10 CFR 20 y by EPA STD.

Accidents No Directly Applicable Limit >

• Weste package to meet contelnment period of not less then 300 years nor more thw 1000 years.

- Unrestricted Area

• Engineered berrier system to Normal Operation EPA STD. (~)6 mrom/yel -

10 CFR 20 Er 10 CFR 80.111 h meet 10' release rate.

1 Accidents 10 CFR 80.2 (500 mreme per eventi e

• 1000 years groundwater travel time to accessible environment.

Other Supporting S port for Meetinn EPA STD.

• * "*" en Performance Objectives Assure Ahllity to Retrieve _

10 CFil 80.111(b)

• Maintain Integrity of the waste package.

m Maintain Stable Openings

• Assure construction-releted to CFR 60.133(al ef fects (e.g., subsidence, frecturing) do not result in significant transport pathways.

Non-T:T2:f:al I 5efety

- Concerne Such es Covered in m (Protection of Workers '

MSHA/ OSHA flegulations 1,

from injury end Death!

'See 10 CFR 80 for further details.

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t 11 Appendix A PUBLIC LAW AND REGULATORY FRAMEWORK This NRC Generic Technical Position is guided by the Nuclear Waste Policy Act, the technical criteria of the NRC rule, 10 CFR 60, and supplements Regulatory Guide 4.17 (Standard Format and Content of Site Characterization reports for High-Level Waste Geologic Repositories).

Nuclear Waste Policy Act of 1982 (NWPA)

The NWPA states in Section 113(b) "that before proceeding to sink shafts at any candidate site, the Secretary [00E] shall submit for such candidate site to the Commission and to either the Governor and legislature of the State in which such candidate site is located, or the governing body of the affected Indian tribe on whose reservation such candidate site is located, as the case may be, for.their review and comment ... C) A conceptual repository design that takes into account likely site-specific requirements."

Nuclear Regulatory Commission Final Pule (10 CFR 60) 10 CFR 60 states in 60.11 (a)(6)~ "that a site characterization report must contain a description of the site characterization program including ... (ii) a conceptual design of a geologic ~ repository operations area appropriate to the named site in sufficient detail to allow assessment of the site characterization program, with respect to investigation activities which address the ability of the site to host a geologic repository and isolate radioactive waste, or which may affect such ability." (Revision of this provision, to conform to the statutory language is currently under consideration).

l The design criteria for a geologic repository are given in 10 CFR 60,130-135. 1 The criteria for performance confirmation are given in Subpart F,  ;

10 CFR 60,140-143 and the criteria for Quality Assurance are given in Subpart G, 10 CFR 60.150-152.

l Regulatory Guide 4.17 Regulatory Guide 4.17 (Standard Fonnat and Content of Site Characterization Reports for High-level Waste Geologic Repositories) states that information on l the conceptual design of a repository is needed to allow for an assessment of l l

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'O 12 the site characterization program, since a substantial amount of the information generated during site characterization will directly relate to the progressive development of a repository design for the site. This document is presently being updated to allow for changes made by the NWPA.

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13 Appendix B DEFINITIONS Alternative Design Concepts - Concepts other than those shown in the comprehensive geologic repository design that may be integrated into the geologic repository and still allow the performance objectives of 10 CFR 60 to be met.

Barriers Important to Waste Isolation- Those natural or Engineered barriers that contribute to meeting the containment and isolation requirements of 10 CFR 60.

Conceptual Design of a Geologic Repository - A design of a geologic repository appropriate to the named site specified in sufficient detail to allow an assessment of the site characterization programs activities that (1) address the ability of the site to host a geologic repository and isolate radioactive waste; or (2) that may affect the ability of the site to host a geologic repository and isolate radioactive waste.

Design Basis - Information which identifies; a) the specific functions to be performed by the structures, systems, or components of a geologic repository; b) assumptions regarding design controlling parameters; c) the specific parameter values selected as a basis for the design; and d) the supporting rationale for assumptions and parameter value selection.

Design Concept - A selected option for the design of a geologic repository (e.g., vertical emplacement of waste packages).

Design Process - An iterative process of developing a geologic repository design from the preliminary stages where the level of uncertainty in design inputs is high, to a final stage where the level of uncertainty is low enough ,

to meet established performance criteria.

Interim Performance Requirements - Quantified reliability and confidence requirements for the engineered barrier system of a geologic repository (e.g.

requirements for a waste package) at the time of the SCP, l Model - A representation of a process, component, or system.  ;

l Performance Assessment - The process of quantitatively evaluating component dnd system behavior, relative to containment and isolation of radioactive waste, to support development of a high-level waste repository and to determine compliance with the numerical criteria associated with the regulation 10 CFR 60.

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14 Reliability - The probability that a system or component, when operating under stated environmental conditions, will perform its intended function '

adequately for a specified interval of time.

Sensitivity Analysis - An analysis in which one or more parameters are varied to observe their effects on the performance of a system or some part of it.

Such an analysis requires definition of a system, the ranges of parameters over which the system is to be investigated, and the characteristics of the system which is to be observed.

Site Characterization: - The program of exploration and research, both in the laboratory and in the field, undertaken to establish the geologic conditions and the ranges of those parameters of a particular site relevant to the procedures under 10 CFR 60. Site characterization includes borings, surface excavations, excavation of exploratory shafts, limited subsurface lateral excavations and borings, and insitu testing at depth needed to determine the suitability of the site for a geologic repository, but does not include preliminary borings and geophysical testing needed to decide whether site characterization sbculd be undertaken.

Site Characterization Plan - A general plan for site characterization activities for a candidate site for a high-level waste repository, as required in the Nuclear Waste Policy Act.

System or Component Performance - How each element or a combination of all elements of the engineered barrier system of the geologic repository contributes to meeting the numerical performance objectives set forth in 10 CFR 60.113.

Uncertainty - A qualitative or quantitative term referring to the confidence in a system's or component's reliability.

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