Memoirs of Roger Max Zimmerman Volume 3 Yucca Mountain Project

By Roger Zimmerman

This volume highlights the activities related to conducting experiments to evaluate how a volcanically- deposited, ash flow deposited geological material will perform if subjected to excavations and deposits of heat generating nuclear waste canisters in welded tuff layers deep underground at Yucca Mountain. Four major experiments were conducted in a similar layer of welded tuff in an underground tunnel some 45 miles away that is located on the Nevada Test Site. Details of preparing and conducting experiments are provided and dialog is presented to illustrate how miners and engineers worked together to achieve the desired objectives.

• Language: English
• Publisher: Roger Zimmerman
• Release date: Feb 16, 2021
• ISBN: 9781735959672

Book preview

MEMOIRS OF

ROGER MAX ZIMMERMAN

VOLUME 3: YUCCA MOUNTAIN PROJECT

by

Roger Max Zimmerman

Smashwords Edition

Published on Smashwords by:

Roger Max Zimmerman

Memoirs of Roger Max Zimmerman

Volume 3: Yucca Mountain Project

Copyright 2021 by Roger Max Zimmerman

ISBN 978-1-7359596-7-2

Library of Congress Control Number: 2020922418

All rights reserved. Without limiting the rights under copyright reserved above, no part of this publication may be reproduced, stored in or introduced into a retrieval system, or transmitted, in any form, or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of both the copyright owner and the above publisher of this book.

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• • •

About the Cover

The cover shows four mountains that represent places that have greatly influenced my life. Four were selected to recognize the sacred mountains that represent the thinking, knowledge, and the way of life for the Navajo Indians, who were the dominant culture in my early years. The Navajos use these mountains to understand stories of the past, present, and to deal with the future. I find that the mountains I have selected represent things that were part of my past and hopefully these interpretations will be useful to those in the future who might be interested in engineering, education, and some history related happenings around the turn of the Twenty First Century. The Navajos selected the four mountains along geographical directions to indicate foundations for their ways of life. The Sacred mountains were Blanca Peak near Ft. Garland, CO (East), Mt. Taylor near Grants, NM (South), San Francisco Peaks near Flagstaff AZ (West) and Mt. Hesperus near Durango, CO (North). I have selected Hosta Butte, near Mariano Lake, NM (West), the Flatirons near Boulder, CO (North), the Organ Mountains near Las Cruces, NM (South) and South Sandia Peak near Albuquerque, NM (East).

CONTENTS

INTRODUCTION VOLUME 3

INITIAL UNDERGROUND TESTING IN NEVADA FOR NUCLEAR WASTE STORAGE

Background

Getting Hired at Sandia

Working on the NNWSI Project

Delay Driven Repository Development Program

Geo-Mechanical Requirements – 1982

Changing Priorities within Sandia

Background on Tuffs

Geo-Mechanical Features of G-Tunnel

Mentor for G-Tunnel Testing

Exposure to Unions

Quality assurance

GTUF Experiments

SMALL DIAMETER HEATER EXPERIMENTS

Introduction

Geological Repository Concept

Fielded Experiments

Data Acquisition System

Experiment Results for IW and IIW

Lessons Learned

Personal Reflections

HEATED BLOCK EXPERIMENT

Introduction

Objectives and Operations

Experiment Activities

Pre-Slot Cutting Activities (Activity I)

Drilling of Instrumentation Holes (Activity II)

Slot-Cutting Period (Activity III)

Data Acquisition System

Instrumentation Installation (Activity IV)

Establish Flatjack Initialization Pressure (Activity V)

Ambient Temperature: Biaxial Pressure Changes (Activity VI)

Thermal Cycle Testing (Activity VII and Activity IX)

Block Temperature Measurements

Horizontal Fracture Development

Residual Ambient Temperature Testing (Activity VIII)

Thermal Cycle Data Analyses

Thermal Expansion Evaluations

Shear Strength Testing (Activity X)

Final Flatjack Failure

Uniaxial Testing Data Analyses

Numerical Modeling Evaluations

Shear Strength Determinations

Summary and Conclusions

Personal Reflections and Lessons Learned

WELDED TUFF MINING EXPERIMENT

Introduction

Purpose

Experiment Layouts and Geology

Drift Convergence

Convergence Data

Rock Mass Rating Techniques

Control Blasting

Control Blasting Techniques

Smooth Blasting Techniques

Explosives

Final Product

Drift Mining Problems

Rock Mass Disturbance Evaluations

Additional Measurements

Borehole Grouting

Numerical Calculations

Summary and Conclusions

Special Instrumentation Evaluations

Experiment Conclusions

Lessons Learned

Personal Reflection

PRESSURIZED SLOT TESTING

Introduction

Principles in Investigation

Pressurized Slot Measurements

Summary and Conclusion

Lessons Learned

CLOSURE TO UNDERGROUND PROJECTS

APPENDIX

Appendix A – Data acquisition System

Appendix B – Co-Authors of Technical Reports and Papers

ACKNOWLEDGEMENTS

ABOUT THE AUTHOR

MEMOIRS OF ROGER MAX ZIMMERMAN

INTRODUCTION VOLUME 3

This document is the third of 5 that have been prepared as memoirs for Roger Max Zimmerman. The collection includes: Family, Academic Life, Yucca Mountain Project, Above Ground Activities, and Volunteer Activities. This document on the Yucca Mountain Project, which was first drafted in 2014, has 5 major chapters: Initial Underground Testing in Nevada for Nuclear Waste Storage, Small Diameter Heater Experiments, Heated Block Experiment, Welded Tuff Mining Experiment, and Pressurized Slot Testing. The Appendix has a section describing Data Acquisition System Instrumentation.

The primary purpose of the underground testing, which was sponsored by the Nevada Nuclear Waste Storage Investigations (NNWSI), was to determine whether selected underground rock media on or adjoining the Nevada Test Site could be technically acceptable for building a licensed, permanent, high-level nuclear waste repository. One of the responsibilities of Sandia National Laboratories was to assess the geo-mechanical (strength, deformational) and hydrological (moisture content, moisture migration) properties of the potential host rock of welded tuff located deep underground at Yucca Mountain.

The experiments discussed in this volume represented a total learning experience to me. I had been underground before, but I had not taken any measurements in that environment. Just think, we had to excavate a hole or cavity in the rock mass to be there to take a measurement. How much of the rock mass was disturbed in making this intrusion, and what might be the effects of the excavation on the measurements? This means that most everything that I discuss in this document was new to me. Working with explosives was new as well. I didn’t know what welded tuff was in 1980.

There are two features in this volume: (1) presenting dialogue illustrating some of the verbal exchanges I had with primarily union-based tunnel personnel and (2) providing a state-of-art summary of underground instrumentation and data acquisition systems that were used underground in the 1980s, which had potentials for future repository use. An important part of our work was to operate with an active Quality Assurance (QA) program. To do any work, we had to write detailed test plans, follow special procurement and operation procedures for test control, and be subject to formally resolving non-conformances when they occurred. This was challenging as we were trying to determine performance of a thin-layer of welded tuff about a quarter mile below the surface of Rainer Mesa. Since we couldn’t predict the behavior of the tuffs, the non-conformances were primarily focused on instrumentation and data system operations.

Four experimental efforts are described. At the ends of each chapter, there are discussions of lessons learned, and, when appropriate, personal reflections regarding the efforts. Closure to my functions as the leader of G-Tunnel testing is provided at the end of the chapter on Pressurized Slot Testing. A feature is development of a diamond-tipped chain saw capable of cutting slots in hard rock.

INITIAL UNDERGROUND TESTING IN NEVADA FOR NUCLEAR WASTE STORAGE

BACKGROUND

This is a personal adventure in exploring the secrets of a volcanically deposited rock formation that could be used to house the nation’s first nuclear waste repository. The adventure involves conducting underground research in volcanic tuffs, located on the Nevada Test Site (NTS), that are similar to those at the proposed storage site of Yucca Mountain.

The need for this new research started in 1977. In that year, the Department of Energy (DOE) started investigating programs to safely dispose of the growing quantities of nuclear wastes that were being accumulated at nuclear power plants in an environmentally acceptable manner. The DOE determined that the safest and most feasible method was by storing them in mined geologic repositories. The DOE started the Civilian Radioactive Waste Management (CRWM) program to address this issue. In 1978, the DOE determined that a nuclear waste repository located in the southwestern portion of the Nevada Test Site (NTS) would not interfere with nuclear weapons testing programs. Thus, the Nevada Nuclear Waste Storage Investigations (NNWSI) were formed with the purpose of conducting site-exploration and regional studies at the Nevada Test Site (NTS), and it became part of CRWM.

Early site-exploration investigations on the NTS were concentrated on evaluating granite, argillite, and tuff formations. After reviewing the geologic, geophysical, and hydrologic data for the potential sites, the primary attention in 1979 was focused on the tuffs at Yucca Mountain, which was located on federal land adjacent to the NTS in Nye County, Nevada.

One of the participants of NNWSI was Sandia National Laboratories (SNL). SNL had the responsibility to characterize the geo-mechanical behavior of the host rock. I interviewed at Sandia early in 1980 and joined a team shortly later with the goal of making contributions towards developing the nuclear waste repository at Yucca Mountain. I knew I was recruited to get in on the start of a monstrous project that had significant national implications. This was exciting and represented a professional challenge that I couldn’t pass up. I worked on the project for 8 years and this document explains how I met the challenges that were presented.

Yucca Mountain is a ridge line in the south-central part of Nevada near its border with California. In 1980, the first of a series of major stratigraphic and hydrologic holes were drilled at Yucca Mountain. A desirable outcome of the drilling was that there was a reasonably thick layer of welded tuff at about 1200 feet below the land surface, and it was about 550 feet above the static water table. Having the static water table far below the contemplated storage formation was a desirable feature as water was not expected to fill the repository after it was closed. Thus, studies towards using the tuffs at Yucca Mountain intensified.

Preliminary studies indicated that thin layers of tuffs in G-tunnel (tunnel designations are those originally established at the NTS) contained welded and non-welded tuffs that had similar properties to those in Yucca Mountain. Use of this weapon’s testing tunnel provided economic access to a similar variety of the tuffs at about the same depth as the candidate repository horizon at Yucca Mountain. G-Tunnel was located on the NTS some 40 miles from Yucca Mountain so personnel could go to either site if needed. G-Tunnel was available for immediate field experimentation without extensive excavation and facility development costs. This was a technical windfall.

NNWSI elected to use G-Tunnel for exploratory field-scale testing. SNL had program responsibilities for G-Tunnel and the NTS branch of Sandia, not part of NNWSI, provided administrative support for operations there. The NNWSI branch of Sandia had program responsibilities to develop the geo-mechanical testing program. These two groups became partners. A technical topic called rock mechanics (response of rock to thermal and structural changes) was being emphasized as part of the geo-mechanical effort. Rock Mechanics related data were to be obtained in G-Tunnel to establish and improve the methodology to be used for testing and evaluating the horizon of interest at Yucca Mountain.

Late in 1979, a rock mechanics research and test area was being initiated about 1.0 miles back in G-Tunnel for conducting tests and experiments for NNWSI and for obtaining tuff samples for testing in the laboratory. Rock Mechanics data were to be obtained for two purposes: (1) provide data and testing methodology to support repository design efforts and (2) provide early testing experiences in welded tuff that would facilitate design and construction of an Exploratory Shaft Facility (ESF) at Yucca Mountain. In the early years, the ESF would have a lined, 12-foot diameter vertical shaft, called the Exploratory Shaft (ES), which would provide direct access to the candidate repository horizon, where, through the use of mined drifts and horizontal drillings, the candidate tuff could be studied in detail and tested in its existing environment. Testing in welded tuffs at G-Tunnel would greatly facilitate the design of the ESF and ES.

GETTING HIRED AT SANDIA

The transition on changing from working on outer space problems to those located underground started when I applied for a job at SNL. I was residing in Albuquerque and working at the Albuquerque Development Laboratory (ADL), which was part of the Rockwell International Science Center. The Science Center was headquartered at Thousand Oaks, CA and had started a satellite facility in Albuquerque with the hope of expanding their technologies in New Mexico. The ADL had been started in 1978 and I joined in August of 1979 as a Visiting Scientist. I had this title because it was easier for Rockwell to justify my position and provide additional benefits. Unfortunately, Rockwell didn’t have a special category for a visiting engineer. In this capacity, I was on a leave of absence from New Mexico State University. Some changes at ADL led to the submission of an application and the eventual new job at Sandia.

In January of 1980, the head of the ADL called me in and privately told me that the future for the ADL was uncertain and I should recognize that my goal of working there for two years was in jeopardy. I went home with that information and discussed it with my wife Betty. We had recently purchased a town house and were getting comfortable in Albuquerque. We talked it over and decided that I would see what job opportunities might be available. I got a job application form from SNL and filled it out. I turned it in early in February of 1980. I got a call from the personnel office and they told me that they would like to interview me to work on a large project involving the storage of nuclear wastes. These were wastes from the nation’s commercial nuclear reactors. This area would not be in the prime responsibility of SNL, which was to provide engineering services for the nation’s nuclear weapons program, but it was important to the DOE and to our nation’s future. I knew very little about SNL or the needs of a nuclear waste repository, but I thought I would like to find out what they had in mind, so I scheduled a two-day interview late in February.

I was traveling to Downy, CA on a regular basis to work on the Space Shuttle program. On a Friday, I flew to Phoenix to meet Betty, my parents, and Betty’s parents. Betty’s parents lived in Tempe and mine in Scottsdale. There was serious flooding that weekend and travel between the parents’ homes was difficult at best. During this weekend, I prepared some slides about the Space Shuttle program I was working on, and, on Sunday, we returned by plane to Albuquerque so I could interview at Sandia on Monday and Tuesday.

I was scheduled to interview for two programs at Sandia: the NNWSI and the Waste Isolation Pilot Project (WIPP). Lynn Tyler with NNWSI and Tom Hunter with WIPP were division supervisors and were trying to build their staffs for these new DOE thrusts. Lynn’s son and son-in-law both had had me as a professor at NMSU. They recommended me and, if you think of it, it is rewarding to be recommended by former students. I somehow got on the Kirtland Air Force Base (KAFB) and found the personnel office. Navigating around the base was a completely new experience to me.

Once I got to the personnel office, I was provided an orientation about Sandia and its mission. I was told about security classification systems and technical areas where I couldn’t visit. In their terms I was uncleared, and this meant that I needed an escort if I went anywhere within the secure area. I had been exposed to a low level of security at the Rockwell International facilities, so I had some inkling of what was involved, but this had not prepared me for the rigors of a Q clearance at a DOE laboratory. If hired by Sandia in the nuclear waste programs, I would be not be working in the weapons program, but I would need the clearances to be able to work on them if needed. I was told that it would take several months to get me cleared. If hired, I would have to reside in an area for uncleared personnel, which I later learned was called the leper colony. I got interested in the technical challenges presented and accepted the fact that there would be some hurdles that I would have to clear before I could become fully productive. I was used to working at a high level and I expected to do the same at Sandia. As I found later, residing in the leper colony made this expectation extremely challenging.

Lynn was my primary sponsor and he wanted me to work on field testing at the NTS. The NNWSI program was in its infancy and Sandia had the responsibility to characterize the geo-mechanical behavior of welded tuffs at the NTS, particularly at Yucca Mountain. People would reside in Albuquerque and commute as needed to the NTS for the on-site explorations. He told me that there was a tunnel on the NTS that had been used in nuclear weapons investigations and it had some tuffs that were similar to those at Yucca Mountain. Investigators could characterize the lightly studied tuffs at G-Tunnel while preparations were being made to sink the ES into the welded tuffs inside Yucca Mountain. They wanted a somewhat mature person to head the field-testing efforts. I had worked extensively in testing of concretes and had been involved in other major field-scale testing efforts at New Mexico State University. To accept this responsibility meant that: (1) I would have to work in a new technical field, and (2) there would be considerable travel to the NTS. Sandia tried to make travel to the NTS as easy as possible. They even had a DC-9 to carry workers back and forth from Albuquerque to the NTS on a weekly basis. This was a big operation, and I was impressed.

Tom Hunter was involved with the WIPP project. He had a similar need for the facility near Carlsbad, NM. Here they already had access to the primary storage medium. The wastes were not as heavily heat producing as those at the NTS, but there were other challenges. The storage medium at WIPP was a salt deposit and excavated drifts had significant creep and would close in a few years. All underground investigations had to be designed with this factor in mind. Tom was particularly interested in my activities in developing a testing program for the Space Shuttle tiles and always identified me with this effort. In 2003, when the Space Shuttle Columbia tragically crashed, Tom was a senior Vice President at Sandia and, when Sandia was asked to participate in the investigation of the failure, Tom was the responsible Vice President in charge. He made sure that I was part of the investigation team even though I was retired at the time. I have pieces of Space Shuttle tiles that the team could study. I proudly have a plaque from Lockheed-Martin signifying my participation in the Space Shuttle Investigation team that year. I might add that the team was the first to accurately predict the cause of the failure. They did this with numerical models, and this was confirmed in tests in Texas.

Now back to my interview. I was exposed to the two projects. I met personnel in both Sandia divisions, and I was told that they would like for me to join them. Apparently, Sandia was willing to let me come up to speed in the specialized study of rock mechanics. Before I left the interview, I would have to select one project as my primary choice. I was torn between the much larger NNWSI project and the New Mexico based WIPP. I finally decided that the NNWSI offered a longer term and larger potential and I selected it. I was told that they would be in touch. I left the KAFB premises with a feeling that the interview went well, and there could be some exciting and interesting challenges in developing a facility for the storage of nuclear waste. The next day, I was back working on the Space Shuttle program.

In about the middle of March, a Rockwell International Vice President came to the ADL and sadly announced that the ADL would be closing at the end of the month. As I remember, this affected about 37 people. After this announcement, he pulled me aside and told me that, since I was a Professor on leave from NMSU and was working on the Space Shuttle program, I would not be impacted by this decision. I would be retained at the ADL until the end of the semester. They wanted me to continue working on the Space Shuttle and encouraged me to transfer to another Rockwell facility. There were about 6 of us who had sponsored projects at the ADL, and we moved to a nearby facility on the first of April.

During the next month, I decided to see what Rockwell had to offer. I knew what was available at the Rockwell facility in Downey. I traveled to the Science Center in Thousand Oaks for an interview. They had some interesting projects that would apply after the first Space Shuttle was launched, but I didn’t see any that really caught my attention. Betty was with me on one trip and we found that living in the Thousand Oaks area would be expensive and we weren’t sure that Rockwell would offer us enough money to make the move. We were thinking about what we were going to do when I got a call from Lynn Tyler. They wanted to hire me at Sandia for the NNWSI project. I accepted on the spot.

I joined Sandia on April 30th of that year. I remember the date well. I wanted to join in May. Lynn told me that, if I joined before May 1st, I would be eligible for a full year’s raise the following October. If I delayed, I would be only eligible for a one-half year’s increment. It didn’t take me long to make arrangements to start in April. Rockwell International was most accommodating.

WORKING ON THE NNWSI PROJECT

After April 30, I was located in the leper colony and was starting to get immersed in the needs of a nuclear waste repository. I had to learn a new vocabulary. The concept was that canisters containing spent fuel or other highly radioactive materials would be stored in underground drifts located in welded tuffs. This geological storage facility would not provide a threat to the nearby citizens. This was just the start of my introduction.

A major focus of the SNL operated geo-mechanical program was to find the suitability of establishing the ESF at Yucca Mountain. The ESF was to provide geo-mechanical answers to questions regarding the suitability of storing spent fuel in this medium and to provide access to the geologic medium so that LANL and LLNL could fulfill their responsibilities. Los Alamos National Laboratory (LANL) was responsible for radionuclide containment and Lawrence Livermore National Laboratory (LLNL) was responsible for hydrologic containment.

I will discuss some of the technical features of tuffs later. For purposes of this introduction, I need to introduce the primary features. Tuff is a form of volcanic rock that was classified as either welded or nonwelded. Tuffs are formed from ash that spews out of volcanoes. Tuffs are different from the basalts that flow as a molten lava out of the calderas of the volcanoes. Welded tuffs are ash-flow tuffs. Ash-flow tuffs are deposited as sheets from a gas-charged density cloud that rolls down the slope of the volcano. This cloud can roll for miles and it picks up debris from the land that it is rolling over. When the glass- based particles come to rest, and, under certain conditions which I will discuss later, they tend to fuse together and form a hard and strong rock. The denser welded tuff formation at Yucca Mountain was selected as the host formation for the repository.

Nonwelded tuffs are ash-fall tuffs that are emplaced by the aerial settling of the ash particles. These glass-based particles bond together forming a relatively light and soft rock. Many of the rock formations around Los Alamos in New Mexico are ash-fall tuffs. Nonwelded tuffs normally were placed above and below the layers of welded tuffs.

There are no minerals in tuffs and the mining potential for removing valuable minerals was non-existent. This means that the geo-mechanical properties of welded tuffs had not been studied by the rock mechanics community. In the case of a repository, the environmental forces would be driven by the presence of the heat generated from the decaying radioactive