ML051530459

Special Nuclear Material Control and Accountability Project, Final Report

ML051530459
Person / Time
Site:	Humboldt Bay
Issue date:	05/27/2005
From:	Pacific Gas & Electric Co
To:	NRC/FSME
References
+sispjld120050609, HBL-05-017
Download: ML051530459 (189)

Text

PG&E Letter HBL-05-017 HUMBOLDT BAY POWER PLANT UNIT 3:

- SPECIAL NUCLEAR MATERIAL CONTROL AND ACCOUNTABILITY PROJECT A

FINAL REPORT',

I

TABLE OF CONTENTS 1.0 EXECUTIVE

SUMMARY

1-1

2.0 INTRODUCTION

2-1

2.1 BACKGROUND

.2-1 2.2 INITIAL INVESTIGATION 2-2 2.3 SPECIAL NUCLEAR MATERIAL INVENTORY, INSPECTION AND CONTROL PROJECT (PROJECT) CHARTER 2-3 2.4 METHODOLOGY 2-6 2.4.1 Document Search..................................

2-6 2.2.2 Interviews 2-9 2.4.3 Project Database 2-9 2.4.4 Videos 2-10 2.4.5 Physical Inspections 2-11 2.4.5.1 SFP Inspections..................................

2-11 2.4.5.2 Non-SFP and Site Area Inspections............... 2-13 2.4.6 Timeline 2-15 2.4.7 Scenario Development 2-16 3.0 SPECIAL NUCLEAR MATERIAL CONTROL AND ACCOUNTABILITY...... 3-1 3.1 HISTORY 3-1 3.1.1 SNM History 3-1 3.1.2 Regulatory History...................

3-4 3.2 FUEL 3-6 3.2.1 Assemblies 3-7 3.2.1.1 Unmodified Assemblies.................

3-8 3.2.1.2 Modified Assemblies.................

3-9 3.2.1.3 UD-6N Assembly.................

3-10 3.2.1.4 Reprocessed Assemblies.................

3-11 3.2.1.5 Returned Assemblies.................

3-12 3.2.2 Fragments 3-13 3.2.3 A-49 3-20 3.3 NON-FUEL SNM 3-22 3.3.1 Incore Detectors (Ion Chambers) 3-22 3.3.2 Fission Chambers 3-27 3.3.3 Pu/Be Neutron Sources 3-28 3.4 SNM WASTE 3-28 3.4.1 SNM Shipped Offsite as Part of Radioactive Waste Shipments..

3-28 3.4.2 SNM Outside of its Original Application and Incapable of Precise Characterization 3-29 3.4.3 SNM Waste Distributed on SFP Surfaces.

3-31 3.4.4 SNM Waste in Interim Storage Container 18 (ISC-18)........

3-32 3.4.5 SNM Waste in SFP Demineralizer and Resin Disposal Tank..

3-33 Page 1 of 3

-,TABLE OF CONTENTS (Continued) 3.4.6 SNM Waste in Diversified Technologies Services (DTS) Vacuum Demineralizer....................................... 3-34 3.4.7 SNM Waste in.Tn,Nuclear, Filters.........................................

3-35 3.5 RECORDS 3-36 3.6 PROCEDURES 3-37 3.7

SUMMARY

AND RESULTS

.3-38

3.8 REFERENCES

3-40 4.0 SCENARIOS FOR MISSING FUEL ROD SEGMENTS 4-1 4.1 SPENT FUEL POOL PHYSICAL INSPECTION 4-1 4.2 ONSITE INSPECTIONS OUTSIDE THE SFP.4-13 4.3 LOW LEVEL RADIATION WASTE SHIPMENTS

.4-15 4.4 OTHER DIRECT SHIPMENTS.4-22 4.5 THEFT or DIVERSION 4-24 4.5.1 Theft by an External Entity.4-25 4.5.2 Theft by an Insider (Authorized Individual).4-25 4.5.3 Unauthorized Disposal (Diversion).4-25 4.5.4 Barrier Analysis.4-26 4.5.5 Other Supporting Analyses.4-27 4.5.6 Conclusions.4-28 4.6 IMPLAUSIBLE SCENARIO - OTHER DIRECT SHIPMENTS AND LOW-LEVEL RADIOACTIVE WASTE SHIPMENTS..

4-29 4.7 A-49 SEGMENTS IN AN ALTERED CONFIGURATION..

4-30 5.0 CONCLIUSIONS..

5-1 5.1 PROBABILITY RANKING.5-1 5.2 HEALTH AND SAFETY.5-4 6.0 CAUSE ANALYSIS AND CORRECTIVE ACTIONS...

6-1 6.1

SUMMARY

6-1 6.2 PROBLEM STATEMENT

.6-4

6.3 BACKGROUND

6-5 6.3.1 Plant Culture.6-5 6.3.2 Procedures.6-7 6.3.3 Inspections, Audits, Regulations, and Guidance.6-8 6.3.4 Fuel Fragments and Fuel Segments.6-9 6.3.5 Ion Chambers.6-10 6.4 EVENTS DESCRIPTION.6-10 6.5 CONSEQUENCES, CAUSES AND BARRIERS

.6-12 6.5.1 Consequences.6-13 6.5.2 Causes.6-14 6.5.3 Barriers.6-15 6.5.4 Untimely Recognition of Loss of SNM Accountability.

6-17 6.6 RECOMMENDED CORRECTIVE ACTIONS

.6-18 6.6.1 Immediate Corrective Actions (ICAS).6-18 6.6.2 Corrective Actions to Prevent Recurrence (CAPRS).

6-18 Page 2of3

TABLE OF CONTENTS (Continued)

6.7 REFERENCES

6-19 7.1 ATTACHMENT (HBPP SNM PROJECT TIMELINE)

Page 3 of 3

1.0 EXECUTIVE

SUMMARY

In November 2003, while characterizing -irradiated hardware to prepare for future decommissioning work, Humboldt Bay Power Plant (HBPP) personnel discovered fuel.

fragments stored in the Unit 3 spent fuel.pool (SFP). After an extensive document review, it was determined that the fuel.fragments,-and three 18-inch fuel rod segments cut from assembly A49 in 1968, were not properly accounted for in HBPP special nuclear material (SNM) inventories. In June 2004,1the three A-49 fuel rod segments were declared missing and,- after a comprehensive SFP search was initiated, approximately 175 fuel fragments were recovered.. As a result of the discrepancies in SNM inventory, a complete SNM audit was conducted culminating in the conclusion in February 2005 that one complete and threepartial incore detectors, containing less.-

than one-tenth of a gram of SNM, were also missing.

As these events were developing and associated SNM control and accountability issues were identified, PG&E formed an SNM Inventory, Inspection.and Control Project (Project) to perform a thorough investigation and analysis of the SNM control and accountability program at HBPP. :The Project cataloged and characterized.fuel and non-fuel SNM possessed at HBPP from r1962 to the present to ensure a complete and accurate accounting of all SNM.

Background

HBPP used first generation General Electric (GE) stainless steel-clad fuel rods when it began commercial operation in 1963 and later transitioned to zircaloy-clad fuel rods during thel966-1968 timeframe. The stainless steel-clad fuel rods sustained significant failures during operation.. These failures resulted in fuel fragments that were separated from their parent fuel assemblies during fuel inspection activities and cleaning of assemblies' in the SFP.. These fuel fragments were generally collected and stored in a container in the SFP, but were not precisely characterized or quantified at the time.

Stainless steel-clad fuel assemblies were shipped offsite to Nuclear Fuel Services (NFS) for reprocessing from mid-1969 through 1971. When shipments were made, fuel assemblies were subtracted in their entirety from the SNM inventory, even though fuel fragments from some of these assemblies remained in the SFP. The Project-- -

determined that the SNM inventory became inaccurate following the beginning of shipments to NFS and continued to be inaccurate until corrected in 2004.

In September 1968, one damaged fuel rod in assembly A-49 was cut into three 18-inch segments, placed in a container and prepared to'be'shipped for'analysis. The shipment was subsequently cancelled and the container with the segments was-returned to the SFP. Assembly A-49 was subsequently shipped to NFS for reprocessing in August 1969 and it is unknown if thatsshipment contained the container and/or the' three' segments.

1-1 i

Project Methodology and Reviews Records reviewed by the Project indicate that the three fuel rod segments were stored in the SFP in September 1968, but no records of their subsequent disposition have been found. In an effort to locate the missing segments, the Project conducted systematic searches of the SFP and areas outside the SFP, performed extensive reviews of HBPP historical documents, and conducted numerous interviews of current and former HBPP employees, current and former contractor employees at HBPP, and personnel at interfacing facilities. Other possibilities considered and evaluated included shipment'offsite for reprocessing, shipment offsite for burial at a low level radioactive waste (LLRW) facility, theft or diversion, and the segments being in an altered (broken) configuration in the SFP commingled with other fuel fragments.

Project Instructions were developed and used for several activities considered crucial to the success of the Project. 'These activities included document searches, interviews',

inspection videos, physical inspections, timeline development, and scenario analysis..

The information generated by the Project was collected and organized in a searchable electronic database. The database contains Records Management System (RMS) documents, scanned hard-copy documents, photos, and interview records.

Underwater photography and digital videos were used extensively during the search for the fuel rod segments and characterization of the fuel fragments and non-fuel SNM in the SFP. The videos are cross-referenced by item and location in the SFP and in some instances include voice-overs. The videos'provided useful information to the Project team and outside experts in their analysis and characterization of the fuel fragments.

Physical inspections of the SFP and areas outside the SFP were conducted to search for the three missing fuel rod segments and to gather information needed for control, accountability, and inventory'of SNM (fuel and non-fuel) currently at HBPP. Examples of the discrete areas inspected in the SFP were: fuel rack cells, energy absorber, transfer baskets, channel stripper, pipes, liners, miscellaneous containers and other items in and/or hanging in the SFP, sump, and the SFP floor. Inspection results were documented in Project files.

The Project team identified the following five generic scenarios for the possible disposition of the missing fuel rod segments:

• HBPP Unit 3 SFP

• HBPP onsite storage outside the SFP

• Licensed LLRW storage facilities

• Other direct shipments (ODS) not to an LLRW facility

• Uncontrolled (unauthorized offsite/onsite - theft or diversion) 1-2

A written disposition of each scenario was prepared that included a description of the scenario, investigation, analysis, and conclusions. The conclusions for each scenario either determined the scenario to be implausible or assigned one of the following four categories for possibility of occurrence:

• "Highly Unlikely" means the event is very improbable.

• "Possible, But Not Likely" means the event, while possible, would have a fairly low probability of occurrence.

• "Reasonably Possible" means the event may have occurred.

"Confirmed" means the event did occur.

SFP Physical Inspections SNM 'records'indicate there should be 54 incore detectors in the SFP. After a complete inspection, only 50 complete and three partial detectors were located. The Project team believes the missing incore detectors were erroneously shipped with nondetector-containing sections of the incore strings to a LLRW site, most likely in 1985, as irradiated hardware. It is permissible for LLRW waste sites'to receive incore detectors.

The search plan'for the SFP considered whether any or all of the three unaccounted for 18-inch' fuel rod segments remain in 'the SFP. -'Each location and container in the SFP' was searched with the idea that the A49 fuel rod segments could be in one'or more of three possible physical configuratiois: (A) intact approximately 18-inch long fuel rod' segments, (B) damaged (broken or crushed) fuel rod segments (i.e., fragments), or (C).'

in the pipe container they were last known' to be in. The SFP search also included a configuration (D) the identification of non-fuel SNM and other fuel fragments not specifically'identified as being from A-49.'

The thorough SFP inspections and examinations did not result in the location of the three intact fuel rod segments or the p-ipe' container in which they were originally stored.

However, it was determined that a number of the fuel fragments recovered from the central storage container in'the SFP mry 'be from the assembly AA9 cut fuel rod.

Based on the physical characteristics If fuel fragments found in the SFP, the Project team concludes'that it is "Reasonably-Possible," but not conclusive, that some or all of the three A.49 fuel rod 's'egme'nts and the rdmnants from the cutting process have been found in the SFP as fragments rather than intact segments.'

Inspections of possible lo6ations outside the'SFP were performed in an effort to locate the three missing fuel rod sbgments,'fuel fragments, or other non-fuel SNM. The inspections did not result in the'discovery'of the fuel rod segments, fuel fragments, or other.irradiated SNM.' Inspection of s'v/'eral areas of interest was impractical at this time (e.g., thereactorvessel), but based on available information it was concluded that it is Highly Unlikely" that the'fuel rod segments or fuel fragments could be in those locations.

1-3;

Offsite Shipments Shipments of radioactive waste to LLRW facilities at Barnwell, South Carolina (Barnwell), Beatty, Nevada (Beatty), and the Hanford Reservation in Richland, Washington (Hanford), were reviewed and evaluated to determine if the three fuel rod segments could have possibly been included in any of the LLRW shipments. After investigation and analysis, shipment of the three rod segments to the Beatty facility was deemed implausible. The available information also supports the conclusion that neither the fuel rod segments nor the pipe container were knowingly loaded into any of the LLRW shipments. However, an opportunity for the inadvertent shipment of either the segments or the pipe container would appear to have been possible in each of three 1983 and one 1985 Barnwell shipments and in each of five Hanford shipments during 1986. The likelihood of an inadvertent loading of the segments or pipe container and subsequent shipment to those LLRW facilities was therefore concluded by the Project team to be "Possible, But Not Likely."

Other direct shipments (ODS) are defined as radioactive material shipments from HBPP to another licensee not a LLRW facility. The majority of ODS differ from LLRW shipments for the primary reason that the radioactive material being shipped is not waste, but is material that will be used or processed, which requires unpacking or handling of the material. If the three fuel rod segments or pipe container were included in an ODS, the receiving licensee, with the exception of shipments of assemblies for reprocessing, would have found and identified the fuel rod segments or container as they were not expected to be a part of the shipment.

Of the ODS made by HBPP, only the 15 spent fuel shipments to NFS for reprocessing are considered as plausible candidates for having contained the fuel rod segments and pipe container. It is believed that the cask contents were probably not carefully examined upon receipt for reprocessing by NFS. Interviews with employees who worked at HBPP in the 1960s and subsequent years provided speculative evidence that the three fuel rod segments may have been shipped for reprocessing. The Project team concluded that the fuel rod segments and pipe container could have been included in any of the 15 shipments to NFS and not been detected. Therefore, the Project concluded it is "Possible, But Not Likely" that the three A-49 fuel rod segments were shipped to NFS for reprocessing.

Given that the evidence that the segments have been found in fragment form within the SFP is not conclusive, the Project team concluded that when the shipments to Barnwell and Hanford are considered together with the possible shipment of the rod segments to NFS for reprocessing, in the aggregate it becomes "Reasonably Possible" that the pipe container or the segments themselves could have been shipped to either the Hanford or Barnwell LLRW facilities, or to the NFS reprocessing facility. This is not to say that it was considered reasonably possible that the three segments were sent to one of these facilities when considered on an individual basis. However, when considered as a 1-4

combined possibility, coupled with the fact that no record of the pipe container has been located subsequent to September 1968, and the pipe container was not found in the SFP, it is the judgment of the Project team that the possibility increases from 'Possible, But Not Likely" to uReasonably Possible."

Even though LLRW facilities are not licensed to accept spent nuclear fuel, the addition of three 18-inch fuel rod segments would not change the performance assessment for continued long-term disposal and renewal of each facility's license. The environmental, radiological; and safety programs that assure the safety of long-term storage of radioactive materials are adequate to allow for the continued storage of the relatively small amount of radioactive material in the three fuel rod segments. PG&E concludes that if the three fuel rod segments are buried at a LLRW facility:

• The overall risk from the fuel rod segments is minimal to past, present and future workers and generations of the public.

• There is a very'low probability of inadvertent intruder scenarios resulting in doses in excess of regulatory limits.

• Retrieval of the fuel rod segments would not be justified by arguments concerning public health and safety as a result of the very low risk that the fuel rod segments pose.

Theft or Diversion Three theft or diversion possibilities were considered by the Project team: theft by an external entity, theft by an insider, and unauthorized disposal (onsite or offsite). No evidence was found to support any of these possibilities. The analyses showed that the integrity of applicable barriers was sufficient to deter, prevent, and detect any attempted theft or diversion for unauthorized disposal. The fuel rod segments and incore detectors have essentially no economic or'strategic value, and the high radiation levels associated with the segments and incore detectors would have presented a significant barrier, particularly in the decade following storage in the SFP. The investigations and analyses support the conclusion that the theft or diversion of the fuel rod segments and incore detectors is "Highly Unlikely."

Cause Analysis The cause analysis performed by PG&E-addressed inadequate control and accountability of SNM at HBPP that resulted in inaccurate SNM inventories,- inaccurate material status reports submitted to the Atomic Energy Commission/Nuclear Materials Mariagem ent and Safeguards System/Nuclear Regulatory Commission.

(AEC/NMMSS/NRC), missing fuel rod segments, and missing incore detectors.

1-5i

For the fuel fragments and missing fuel rod segments, the causes were determined to be:

1. Plant management did not require development of procedures for control and accountability of fuel fragments and fuel rod segments.

2. Plant culture in the 1960s and early 1970s encouraged individual problem solving, rather than development and use of procedures for noncomplex evolutions. This approach resulted in activities that were either performed without procedures, or with procedures that would be considered inadequate by current standards.

3. The SNM Custodians were not adequately trained on control and accountability of SNM.

4. There was no specific regulatory guidance for the control and accountability of fuel fragments or fuel rod segments.

5. There was no specific industry experience or standards for control and accountability of fuel fragments or fuel rod segments.

For the missing incore detectors, the causes were determined to be:

1. An inadequate procedure was used to determine the location of detectors in incore strings during cutting operations performed in the 1980s.

2. The SNM Custodians were not adequately trained on control and accountability of SNM.

3. A personnel error - cognitive, for failure to follow the SNM control and accountability procedure for incore detectors.

Conclusions As stated above, based on the physical characteristics of fuel fragments found in the SFP, the Project team concludes that it is reasonably possible that some or all of the three A-49 fuel rod segments and the remnants from the cutting process have been found in the SFP as fragments rather than segments. However, given that the identification of the segments in the SFP is not conclusive and the pipe container was not found, when considering the aggregate of possible sites the segments could have been shipped to, it is also reasonably possible that the segments were shipped offsite to either the Nuclear Fuel Services fuel reprocessing facility or the Barnwell or Hanford low level radioactive waste facilities. All other possibilities have been dispositioned as either highly unlikely or implausible.

1-6

The Project team believes the missing incore detectors were erroneously shipped with nondetector-containing sections of the incore strings to a LLRW site, most likely in 1985, as irradiated hardware. Although it would have been legal and appropriate to send incore detectors to a LLRW facility, their being sent erroneously led to an inaccuracy in HBPP's physical SNM inventory.

Corrective actions to prevent recurrence of SNM control and accountability issues at HBPP have been developed. In addition, PG&E now has an accurate, validated and controlled inventory of all SNM residing at HBPP.

1-7

2.0 INTRODUCTION

This section contains: (1) background information related to the discovery of fuel fragments in the Spent Fuel Pool (SFP), missing fuel rod segments, and missing incore ion chambers, (2) a description of the Phase 1 search of the SFP for the three missing fuel rod segrnents,-(3) the charter for the expanded Phase 2' search'for the fuel rod segments, including a full accounting of special nuclear material (SNM) at Humboldt Ba 'Power Plant (HBPP), and (4) a discussion of the methodologies used to 'gather, store, and display relevant information and to develop plausible scenarios for the missing'fuel rod segments.

2.1 BACKGROUND

During 2003, HBPP plant personnel initiated a review and cataloging of the contents of the SFP in preparation for the planned transfer of spent fuel into an onsite Independent Spent Fuel Storage Installation' (ISFSI). During this process, fuel fragments were discovered in a container in the SFP. As a result, a comprehensive documentation search and review was conducted.

On June 23, 2004,' plant personn'el identified Onsite Review Committee (OSRC) meeting'minutes dated October 2,'1968, indicating that in September of 1968 three 18-inch segments were cut from one fuel rod located in fuel assembly A-49.

These segments were placed into a small container (1-1/2 inch diameter, approximately 2 feet in length, schedule 40 steel pipe with a welded'cap on one end and a threaded cap'on the'other) in preparation for shipment to the Battelle Memorial Institute in'Columbus,'Ohio, for analysis. The shipment to Battelle was subsequently cancelled and the c6ntainer with the three 18-inch segments was returned to the SFP on September 27, '1968. The specific location of this

'container in the SFP was not identified.

On June 25, 2004, after further research, plant personnel found shipping records indicating that in August of 1969 the~entire A-49 fuel assembly was included in a shipment of 18 fuel assemblies to Nuclear Fuel Services Inc. (NFS)'in'West Valley," New York, for reprocessing. No'mention was made in the 'shipping record that the A-49 assembly had been 'shipped with' portions'of onie of its rods left behind in the SFP. No records 'were found that indicated that the removed portion§ of the fuel rod were subsequently placed into the canister later used to ship assembly A-49 to NFS, and no records were found to indicate the final location of the three 18-inch'segments, thus bringing into question'not only the location of the three rod segments, but also the accuracy of the annual SNM inventory provided for HBPP Unit 3,' at least from the time assembly A-49 was shipped offsite for reprocessing..- ; ;

Further review of records did not resolve the discrepancy, and on June 29, 2004, PG&E verbally notified Region 'IV of the NRC of the discrepancy in records and 2-1

the uncertainty regarding the specific location of the fuel rod segments removed from A-49.

On July 7, 2004, PG&E began a physical search of the central storage container (CSC) in the SFP, considered a high probability location for the three 18-inch segments as well as any remnant portions of the A49 rod. During July 9-11, 2004, PG&E recovered fuel rod fragments from the CSC, but the three 18-inch segments were not found intact. On July 16, 2004, HBPP notified the NRC of the potentially lost or missing licensed material in accordance with 10 CFR 20.2201(a)(1)(ii) and 10 CFR 50.72(b)(2)(xi). (NRC Event Notification 40877).

2.2 INITIAL INVESTIGATION The initial investigation into the three missing fuel rod segments (subsequently called Phase 1) was conducted by HBPP personnel and focused on trying to physically locate the three segments. There were initial document searches and interviews of current and former employees who may have had knowledge of the events in question. However, the primary focus was searching the SFP and containers in the SFP for the three fuel rod segments or the pipe container they were last believed to have been in.

Phase I of the SFP search entailed search efforts in locations that were readily accessible and in locations where the probability of finding the fuel rod segments was believed to be highest. It was planned that if the A-49 rod segments were not found in Phase 1, then Phase 2 (which became the Special Nuclear Material Inventory, Inspection, and Control Project (Project)) was to include the search of locations for which more extensive effort, planning, and time would be required, as well as locations originally covered in the Phase I search for which follow-up work was required.

To accomplish the initial search of the SFP, a list of each location in the SFP was established so that it could be searched systematically. The search of each location, and any items found, were documented where possible by video. The video evidence was reviewed to evaluate items found. If the video evidence was not sufficient to conclude that either a location did not contain items or that items could not be accurately identified, that determination was noted and the location in question was to be addressed in Phase 2 by the Project.

In addition to the physical searches of the SFP, Phase I involved extensive reviews of available documentation related to the A-49 assembly and the three fuel rod segments, and interviews of present and past plant personnel who may have had information related to the missing segments. This initial investigation, while fruitful in the sense of gathering a great deal of valuable information, did not determine the location of the A-49 fuel rod segments.

2-2

PG&E determined that Phase 2 would need to be initiated to: (a) continue the searchfor the A-49 fuel rod segments; (b) continue the records search; (c) continue the interviews; and (d) complete a thorough investigation'and analysis of the'Special Nuclear Material Cdontrol and Accountability (MC&A) program at HBPP Unit 3.'

2.3 SPECIAL NUCLEAR MATERIAL INVENTORY, INSPECTION AND CONTROL PROJECT (PROJECT) CHARTER.,

e

~

th Proec expanded Phase 2 of the Project expanded upon prior activities and built on the scope of work from Phase 1 to include a full ccounting of SNM at HBPP. A Project Charter was established that described, among other things, the purpose and functions to' be performed by the Proje'ct. 'As a result of implementing the Charter, the activities described irinthis section were perform6d.

'The Project was performed in accordaqce -with a Project Quality Plan (PQP) and Quality Verification Plan that identified the applicable Quality Assurance (QA) criteria from the 10 CFR Appendix B QA Program, and specified the controls, programs or procedures (HBPP, Independent Spent Fuel Storage Installation (ISFSI) procedures, or others, as applicable) to be used to implement the relevant criteria.1 The PQP provided instructions on how the appropriate QA controls from the SAFSTOR QA Plan and 10 CFR 50 Appendix B would be applied'to the Project.

The following Quality Goals and Objectives were established:

1.

All handling and movement of materials in and over the Unit 3 SFP will

-be in accordance with approved procedures and instructions.

2.

All fuel assemblies will be properly inspected and classified for future ISFSI storage.

3.

All SNM, including fuel assemblies and SNM not specifically contained in an inventoried fuel assembly, (i.e., sources, incore detectors, fuel fragments and/or SNM waste) will be properly identified, inventoried and accounted for.

4.

All SFP objects and items'will be identified and classified for future disposition.

5.

The movement of heavy-loads will be conducted in a planned and controlled manner by qualified p'ersonnel, with no adverse impact on the SFP or other systems, structures or components required for the safe storage of spent fuel.

6.

The Unit 3 corrective action program will be utilized to report all problems.

HBPP Temporary Procedure 2004-09, 'Special Nuclear Material (SNM) Inventory, Inspection & Control Project - Phase 2."

2-3

The Project was given the authority and responsibility to promulgate work instructions'as to how the Project was to achieve its objectives. The Project was also required to develop a Project Plan to provide guidance for the development and implementation of Project documents and Project Instructions (P1s). PIs were required to conform to the SNM PQP and Quality Verification Plan and other relevant HBPP procedures.

To assist the Project the following definitions were derived to provide consistency between Pls, work accomplished during the Project and written records describing activities and documenting findings:

Fuel Assembly: A fuel assembly is a group of fuel rods (also called a bundle) held together in a specific geometry for placement into the reactor core. Most HBPP fuel assemblies are intact, but some are not intact, and some fuel assemblies do not have a full complement of fuel rods. The fuel in the fuel rods contains SNM.

Fuel Segments: Fuel segments are the three cut pieces of a fuel rod from assembly A-49. The fuel in fuel segments contains SNM.

Fuel Fragment: A fuel fragment is a clad or unclad portion of a fuel rod, including pellets or portions of pellets that have a measurable dimension nominally greater than 1/4 inch. Cladding without fuel is irradiated hardware, not a fuel fragment. The fuel in fuel fragments contains SNM.

SNM Waste: SNM waste is waste that contains SNM that originated from either fuel failures during plant operations or from fuel handling. SNM waste is waste that is collectible (i.e., not adhered to a component surface). SNM waste may be greater than Class C waste. SNM waste is not considered to be fuel.

Incore: An incore (also called an incore string) is an assembly of three ion chambers. The ion chamber (also called an incore detector) contains SNM; the rest of the incore is not SNM. An incore segment is a partial length of an incore string which may or may not hold one or more ion chambers.

Video documentation: A generic term that refers to a digital (DVD) recording of visual images of a SFP location or particular item. Intrinsic labeling of a video document refers to information that is electronically embedded in the DVD (e.g., by using the keyboard to write a menu or on-screen text, or by using a microphone to record a voice-over) as opposed to, for example, a hand-written notation on the DVD disc or an attached label.

2-4

Primary search object or item: Any discrete object containing (or possibly containing) a quantity of SNM. This includes, but is not limited to, any fuel rod separated from its assembly, any fuel rod fragment, any piece of incore string containing an ion chamber, or a container that could contain any of these objects.

.Secondary search object or item: Any non-SNM object (e.g., a wrench or a stellite ball). Permanent structures within the SFP, such as the fuel racks or the channel stripper, are not considered search objects; they are locations that may contain search'objects.

The Project was authorized by the Plant Staff Review Committee (PSRC) and the Technical Review Group (TRG) to develop Pis establishing the process to review'docu ments collected for information potentially relevant to the Project investigation and to disseminate that information to the investigators. The Pis established a mechanism to'identify, "collate, file, and maintain thedocumentation in a form suitable for audit. The Pis also established formal requirements for reviewers to document the results of "applicability" reviews of each document.

After the broad scope uapplicability" review, Project members performed another review'for 'relevance" to particular issues. Relevant information was then extracted and included in an event timeline, as appropriate.

The results of the document collection and review, supplemented by information obtained during an interview process, were used to implement and conduct a process designed to develop plausible scenarios to be investigated. Project team members met to identify and discuss various ideas about possible dispositions of the fuel rod segments'and related SNM issues based upon their experience and the information 'contained in the initial document reviews and interviews.

The Project team members suggested and discussed a wide range of ideas for possible scenarios. These ideas were then collected and combined into generic' scenario categories. Each scenario was reviewed and included a concise statement regarding the results of thescenarlo analysis. The scenarios were reviewed as a group to determine the' relative likelihood of each.

The Project conducted interviews of current and former PG&E employees, PG&E retirees, current and former contractor workers at HBPP, and personnel at interfacing facilities, as appropriate. Project team members initiated the process by identifying key individuals responsible for, or directly involved with, various activities concerning the A-49 fuel rod segments, concering movement or' handling of materials in the SFP, or 6therwise potentially having knowledge about SNM ac6ountability issues.' The interviewers prepared written summaries of each interview conducted for use"in the investigation and scenario development. In addition to the primary interviews, the Project team members conducted less formal telephone interviews of individuals.

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The physical search activities were to consist of two distinct areas: (1) the SFP and (2) the balance of the HBPP site. The Project developed a detailed and comprehensive inspection plan intended to inspect all likely and accessible areas in the SFP where fuel fragments or the cut A49 fuel rod segments could be stored. With the assistance of site personnel and suggestions from other organizations, the Project established a comprehensive list of SFP locations capable of physically accommodating the fuel rod segments. The SFP Physical Inspection Plan identified the specific locations to be searched, the.unique characteristics of each location, and the planned inspection method.

In addition to the Physical Inspection Plan of the SFP, a detailed and comprehensive inspection plan was developed intended to identify and inspect all likely and accessible areas outside of the SFP, but within the HBPP owner controlled area where the fuel rod segments could be located. Again, with the assistance of site personnel, the Project established a comprehensive list of locations outside the SFP capable of physically accommodating the fuel rod segments. The identified areas were inspected to determine if the fuel rod segments were present. The results of each area identified and inspected was documented by means of a scenario disposition and in some cases supported by video and/or still photographs.

Finally, the Project was asked to identify and segregate, to the extent practicable, each type of object or item discovered in the SFP. All SNM-containing materials were identified and quantified. SNM-containing materials (excluding SNM waste) were segregated, properly stored and tracked for accountability. Segregation of non-SNM objects and items was to be completed, to the extent practicable, to facilitate future disposition of these materials2.

2.4 METHODOLOGY 2.4.1 DOCUMENT SEARCH The Project, through its Charter, established Pis for various activities. P1-03 addressed Document Investigation. The processes described in P1-03 were designed to identify, retrieve, and review all available documentation containing information that might help determine the location of the three fuel rod segments and to address SNM accountability.

Document search efforts focused on two principal areas - documents microfilmed in the PG&E Records Management System (RMS) and hardcopy document searches. The corporate-wide PG&E RMS was initiated in 1980, 4 years after HBPP Unit 3 had last operated. Historical records, where available, were batched and entered into the system over a period of nearly a decade. The 2 Preliminary radiological characterization of non-SNM items in the SFP has been completed. (Ref.

Report 3095-RE-042, entitled 'Humboldt Bay Power Plant Preliminary Characterization Results,"

prepared by WMG, Inc., dated January 2005.)

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indexing of these documents was, in a number of cases, not done, and in others, not done to a level of detail that would be ~considered ideal.

The RMS system search effortb focused on three areas: (1) the 'master file' microfilm records, (2) the initial key'word RMS microfilm searches, and (3) other RMS searches based on keywords, dates, document types or other document attributes as requested by various Project team members during the course of their investigation.

The RMS master files are un-indexed documents that were entered into the RMS system in a bulk fashion. P1-03 has a complete listing of the microfilm reels containing master files.' This portion'of the document search involved the document by document review of over 100,000 documents.'The kick-off RMS searches were intended to build on the microfilm location of previously collected documents that were relevant to the Project and had been identified as such prior to Chartering the Project.

Finally, other RMS 'searches were' performed to build on the success of the earlier searches. As relevant documents were retrieved from RMS,'PI-03 was updated with key words for reference forffuture searches. Thus, an iterative process for'the subsequent searches was created to' build on the successes of previous searches.'

The hardcopy document search eff6rts included HBPP Unit 3 locations and other offsite PG&E organizations related to fuel, SNM (tracked by the Comptroller's office in the early years of HBPP operation), and legal. This portion of the search effort involved inspection of the contents of over 60 storage receptacles in the plant's historical file storage facility, review of over 10,000 pages of legal documents from the general office legal department, and 'a 'review of over 20 boxes of hardcopy documentsstored in a secondary records storage facility located orisite. Also included in tie hardcopy review were files located in individual offices, plant reference libraries, and storage areas in the plant power block.

The search and retrieval efforts'identified applicable'docurneitation - such as documents that contained key wyords'listed in PI-03.' These 'applicable document packages were reviewed for'relevanicy to the Project. All documentation deemed relevant to the Project was entered into the electronic Project database as well as being filed in the Project file cabinets. Other outside agency documentation was requested and reviewed for applicability and relevancy and appropriately filed for'reference'.

A portion of the document review effort involved digitally'archiving iriortant microfilmed documents. For cases where the microfilmed documents were relevant to the missing fuel rod segments or SNM accountability, a link from the Project database to the digital document was provided.

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The document search and review effort described above was successful in identifying a large majority of relevant documentation. The search/review effort resulted in a complete listing of Material Balance Reports and Material Transaction Reports sent to the Atomic Energy Commission (AEC)/NRC.

The document search efforts were also successful in identifying ancillary/supporting documentation, such as special work permits, burnup calculations, historical SFP maps, historical surveillance test procedures, and other regulatory correspondence.

The extensive search and review effort did not, however, identify certain categories of documents that the Project believes would have been relevant to SNM Material Control and Accountability. The principal documents that could not be located or no longer exist are: (1) the SNM accountability ledgers from the beginning of operation in 1962 through the early 1970s, and (2) the operator logs during the years of plant operation.

Personnel interviews conducted by the Project confirm that the accountability ledgers would have been used to track SNM during the plant operating period when stainless steel clad fuel was used. These ledgers would have confirmed the HBPP SNM Accountability Program and may have included information on the generation of fuel fragments from the stainless steel clad fuel and possibly the three A-49 fuel rod segments. The SNM accountability sheets from the period 1973-1974 to the present are available and constitute the current SNM accountability ledger.

Similarly, the operator logs would have contained entries related to transfer/movement of fuel in the reactor and SFP, preparation for offsite fuel reprocessing shipments, offsite radioactive waste shipments, and special test/unusual events, including, perhaps, the final disposition of the A-49 fuel rod segments. HBPP internal documents from the mid-1960s were found that instructed individuals to put information regarding fuel fragments in the operator logs.

Another category of documents that either could not be located or no longer exist are the power production engineer logs from the same time period. Interviews with individuals who held those positions during the period of interest established the fact that such logs were maintained at the time, but none of them have been recovered and copies do not appear to have been placed in the RMS.

The document search effort involved over 3,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> of document retrieval efforts. This total does not reflect the additional effort to provide a relevancy review and timeline event review that was required for each applicable document. The Project created hardcopy index files documenting each microfilm reel review result and onsite physical searches, and specialized searches (such as law files, etc.) were also documented in the Project files.

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2.4.2 INTERVIEWS A significant amount of data dev'eloped during the Project investigation was

'derived during interviews of past and present employees from HBPP Unit 3.

'The Pl for interviews provided guidance for conducting and documenting those interviews. Interview teams (IT) were formed in preparation'for interviews or series of interviews. The IT typically consisted of two or more Project team members, depending onthe complexity of the interview. On a numVber of occasions however, logistics dictated that a single individual conduct the interview. Instruction' and training was provided for interviewers. Interview data obtained was'assessed to determine relevance, the'possible 'need for follow-up interviews, and was collated against-events established in the overall project timeline. Information'derived from interviews was used to help develop event scenarios and to help prove, disprove, or assess facts related to various scenarios.

During the initial investigation, prior to the formation of the Project, interviews were conducted by HBPP staff. Those interviews were not conducted pursuant to a written instruction but were summarized and made available to the Project.

Significant information was gleaned from those early interviews which was used to, among other things, develop follow-up, interview lists. The list of persons to be interviewed was also added to during the'course of document reviews, person'al recollection of Project team members and persons being interviewed, and from individuals simply coming forward to offer information. Telephone communications associated with'interviewing were also documented.

Additionally, the Project continued to solicit information from site personnel.

Before an interview was conducted; the IT attempted to gather background information related to the association of the individual to the Project objective.

For example, it would obviously aid the IT in knowing time frames and in what capacity the individual may have been involved with events being investigated.

Once this type of information was established, the IT prepared an outline of the basic elements of the interview..Th'ese included, but were not limited to, an opening explanation of the Pr6ject'obje6tive and reason'for interviewing the individual (e.g., why the individual was chosen to be interviewed). Information aides, such as hist6rical dc'6uri ts'asld drawings, maps and diagrams,' and related photos were on hand during the.interviews to help refresh the interviewees'mernory. Each interview was documented arid, where appropriate and if the interviewee was willing, the interviewee reviewed and initialed the notes of the interview or the final typed version. The documentation for each interview was enter'ed in the Project database.

2.4.3 PROJECT DATABASE' The information generated by the Project was collected and organized in a database. The database provides'a searchable index to computer files of 2-9

documents (word-processing files and/or scanned image files), photos, and other computer files, with links to the location of the applicable file, so that the appropriate software can be "launched" to review the information in the computer file (e.g., scanned document images). The database is searchable by document type, topic, keywords, and by a "word search" in text entry fields (e.g., for "relevancy").

The database is comprised primarily of documents that were selected from the PG&E RMS, hard-copy documents that were scanned into the system, photos, and interview results. The PI for the database provided direction for data entry, search routines, report generation, and maintenance. Information related to "who entered which data" was incorporated through other PIs.

In order to permit changes to the user interface without modifying the core database, the database was created in two parts. The data itself is located on a network drive and the user interface is a database application installed on each user's computer. Both parts are Microsoft ACCESS 970 databases.

2.4.4 VIDEOS As noted in Section 2.1, HBPP Unit 3 work was being conducted in 2003 in preparation for dry cask storage. As part of that effort, video documentation on DVDs was utilized in the SFP characterization effort. It was during this effort that the first fuel fragment was discovered in a container in the SFP.

The use of underwater photography and video documentation was utilized extensively during both Phase 1 of the search for the A-49 fuel rod segments during the summer of 2004 and during the duration of the Project. A HBPP A-49 Video Catalog has been created that covers the period from August 2003 to May 11, 2005.

While it is recognized that the video documentation is not considered a quality record, the added documentation and intrinsic labeling does serve as an excellent source of information as to the events that transpired during the search for the A-49 segments, fuel fragments, and non-fuel SNM in the SFP during the course of the investigation. HBPP temporary procedures were utilized to provide direction for the video documentation to help ensure that significant information was retained.

In addition to the basic data intrinsically labeled on DVDs during SFP search operations, the videos have been cross-referenced by item (e.g., UD-6N container, SFP Cell locations, the energy absorber, sump, etc.) to allow a reviewer of the data to review the relevant video data about-a specific item regardless of when it was taken. DVDs regarding specific topics were also compiled with voice-overs to provide added information that might not otherwise be discernible to the viewer.

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The videos were also the source of the still photos utilized by various experts attempting to characterize fuel fragments that had been located in the SFP during the A-49 segments search activities. Those stills are included in the Project database.

2.4.5 PHYSICAL INSPECTIONS The purpose. of the physical inspections was to: (1) search for the three fuel rod segments associated with fuel assembly A49, and (2) perform a comprehensive inventory of and establish physical control.over all SNM (fuel and non-fuel) currently at HBPP Unit 3.

Physical inspections were divided into two discrete categories, both located at HBPP Unit 3. The two categories were:

1. Spent Fuel Pool - designated as HBPP SFP

2. All areas at HBPP outside of the SFP - designated as HBPP Unit 3 Non-SFP and Other Site Areas A systematic, comprehensive, and well-documented inspection of the two categories was performed. The inspections were prioritized based on the likelihood of success, performed in accordance with HBPP Unit 3 procedures, and documented in Project records.

2.4.5.1 SFP Inspections Objective The objective of the SFP inspection plan was to develop a detailed list of possible locations in the SFP that could accommodate: (1) the three fuel rod segments that were removed from fuel assembly A-49 in 1968, the container holding the three segments, or cut pieces, broken pieces, fragments, or jlletsfrom the three segments, or (2) SNM (fuel and non-fuel) currently at HBPP. The inspection methods were designed to gather sufficient evidence to objectively determine the absence or presence of the SNM of interest.

Discussion Although a preliminary search had already been conducted in the preceding months, the SFP Global Inspection Plan was written as if no previous search had beben done.' Credit, however, was taken for physical 'search activities that had already been'completed and adequately documented. Such' previously documented search activities were integrated in the inspection plan with additional physical 2-11

search activities. These search activities were documented in a comprehensive and coherent manner to support conclusions with a minimum of uncertainty.

The three fuel rod segments were last known to have been placed in the SFP within a specially designed pipe container in September 1968.

The inspection plan considered the fuel rod segments to currently be in one or more of three physical configurations in the SFP:--(1) contained in the original pipe container, (2) intact segments outside the container, or (3) broken or cut pieces outside the container.

Previously unidentified and/or unknown SNM could also be present in the SFP in the form of fuel fragments, or as non-fuel SNM (i.e., incore ion chambers, excore fission chambers, startup sources, etc.).

Scope Using the SFP maps of past inspections for consistency, the inspected areas were documented and cross-referenced to specific video tapes and/or CD-ROMs. Additional SFP maps and object descriptions were used to document other free space and discrete inspections.

The discrete area inspections included items listed in the Global Inspection Plan that had and had not been previously inspected and documented. Examples of areas to be inspected were:

Empty Fuel Rack Cells

• Energy Absorber

• Transfer Baskets

• Channel Stripper

• Pipes, Liners, and Miscellaneous Items In and/or Hanging in the SFP

• Sump Containers Acceptance Criteria / Expectations If the fuel rod segments or other SNM (fuel and non-fuel) were to be located, an attempt would be made to identify them by serial number (if possible), and length and diameter measurements, or other identification markings (e.g., file marks). All debris located under the fuel racks and in the SFP between racks was to be identified and/or video taped.

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• A video record with time and date stamps, voice commentary, and/or integral captions of the inspection was generated as applicable and appropriate for the subject inspection.

It was to be demonstrated that the discrete inspection areas and the under rack areas were inspected in accordance with the plan and'that either the-ocation of the missing fuel rod segments or other SNM was identified or that they were not present in the inspected areas.

Documentati6n and Review/Approval of Inspection Results The detailed results of the' inspection were sufficiently documented to ascertain the presence or absence of the fuel rod segments and/or other SNM, and to include review/approval signatures.' The results of the SFP inspections are discussed in Section 4.1 of this report.

2.4.5.2 Non-SFP and Site Area Inspections The three fuel rod segments were last known to have been located in the SFP in a specially designed pipe container in September 1968.

However, the segments could have been removed from the container and the SFP and put elsewhere in Unit 3 or another site location, such as a shielded container, cask, or in a water-filled reservoir. Assuming the segments were misidentified and possibly stored or cut with other irradiated hardware, additional locations could be possible.

Previously unidentified and/or unknown irradiated SNM could also be present in the form of fuel or as non-fuel SNM (i.e., incore ion chambers, excore fission chambers, startup sources, etc.). Since this SNM would not be specifically known or identified, there were various possibilities with regard to the configuration and location of this SNM.

Objective The objective of the' hon-SFP and site areas inspection plan was to develop a detailed list of possible locations at the HBPP site (within the owner-controlled area) that could accommodate: -(1) the three fuel rod segments, the container holding the three segments, or cut pieces, broken' pieces, fragments; or pellets from the three segments, or (2) any previously uniden'tified anrd/or unknown irradiated SNM (fuel and non-fuel). The inspection methods were designed to gather sufficient evidence to objectiv'eiy determine the absence or presence of the SNM of interest.

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Discussion The Global Inspection Plan for areas other than the SFP addressed locations with a potential for storing shielded containers or water-filled areas capable of accommodating the subject SNM. The plan included three general areas: the refueling building, the power building, and the yard and ancillary buildings of Unit 3. Some areas of interest were either currently inaccessible, or were excluded from inspection by means of evaluation and/or existing documentation. The plan took credit for physical inspections that had already been completed and adequately documented. Such previously documented inspection activities were integrated with additional physical search activities to form a single plan. These inspections were documented in a comprehensive and coherent manner to support conclusions with a minimum of uncertainty.

Scope Various onsite locations were identified that could possibly contain the SNM of interest. Due to the dose associated with the fuel rod segments, the potential storage locations were limited. It was also expected that the segments would have had to be stored in a shielded container, which would further limit the potential locations.

Inspection Methods The inspection methods were documented in the inspection plan. As appropriate, inspection locations were to be indexed to HBPP drawings and maps.

Acceptance Criteria / Expectations

• If the fuel rod segments or other items of irradiated SNM were located, an attempt was to be made to identify them by serial number (if an end plug was present), length and diameter measurements, or other identification markings (e.g., file marks).

• It was to be demonstrated that the discrete inspection areas were inspected in accordance with the plan and that either the location of the missing fuel rod segments was identified or that there was no irradiated SNM present in the inspected areas.

Documentation and Review/Approval of Inspection Results The detailed results of the inspection were documented to ascertain the presence or absence of the fuel rod segments and/or other SNM, 2-14

and include review/approval signatures. The results of the non-SFP inspection are discussed in Section 4.2 of this report.

2.4.6 TIMELINE The HBPP Project Timeline3 was utilized as the primary tool to collect and organize relevant information obtained from the implementation of the documentation investigation and interview results. The'Project Timeline is presented graphically year by year from 1962 to the present with annotated depictions of the various events and activities that have transpired and are associated with:

• The three fuel rod segments from fuel assembly A-49 and/or the pipe container that was last documented to hold the fuel rod segments.

• HBPP Unit 3 SNM control and accountability (i.e., physical inventory, physical location, configuration, and material balance data).

The Project Timeline was developed utilizing Microsoft© VISIO software. The software was used to organize, depict, and present the following information:

• Presents the historical evolution of both the AEC/NRC regulatory requirements with regard to SNM material control and accountability, and the HBPP implementing procedures (where available).

• Identifies the appropriate HBPP Unit 3 personnel by title (i.e., reactor engineering, radiation protection, plant operations, etc.) that were responsible for specific and related activities associated with the fuel rod segments from A-49 and SNM material control and accountability (where available).

• Identifies specific events and activities related to the fuel rod segments and SNM accountability.

• Provides information related to the possible disposition of the fuel rod segments.

• Presents' all of the SNM shipments and shielded cask shipments (SNM and low level radioactive waste (LLRW)) from HBPP

• Utilizes the RMS locator'number.(RLOC) or file numbers in most cases for each Project Timeline entry'to 'provide a reference to the relevant document that supports and substantiates the entry 3 The HBPP Project Timeline is Attachment 1 to this Final Report.

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All of the Project Timeline information is presented in a manner that utilizes different colors to identify the specific aspects of the Project Timeline and also to indicate the material control and accountability of the fuel rod segments. In addition to the use of color, the Project Timeline uses spatial areas of each timeline year sheet to further organize and separate related timeline events.

2.4.7 SCENARIO DEVELOPMENT In late 2004 and early 2005, the Project team conducted a process designed to use the information gathered to develop the universe of plausible scenarios to be investigated. With the assistance of an external Oversight Team, Project team members met to identify and discuss various ideas regarding possible dispositions of the fuel rod segments based upon their experience, the information contained in the initial document reviews, and the results of preliminary interviews. A low threshold for scenario plausibility was established in light of the very early stage of the Project.

During Project meetings, team members suggested and discussed a wide range of ideas for possible scenarios with respect to the disposition of the fuel rod segments. The ideas were collected and consensus was reached that the potential scenarios could be grouped into five categories. They are:

1. HBPP Unit 3 SFP.

2. HBPP Unit 3 on site storage outside of the SFP (i.e., radwaste storage containers, high level waste storage vault, etc.).

3. Licensed LLRW storage facilities (i.e., Barnwell, Beatty, Hanford, etc.).

4. Other direct shipments (ODS) not to an LLRW facility (i.e., GE Vallecitos, Nuclear Fuel Services - West Valley, Battelle Columbus Laboratory, Consumers Power - Big Rock Point, GE Wilmington, etc.). and

5. Uncontrolled (i.e., unauthorized disposal offsite/onsite - theft or diversion).

Each of the five categories was treated as a generic scenario. For example, the physical searches of the SFP were developed and dispositioned as a single scenario even though there are over 50 specific physical search locations and items within the SFP. Similarly, while there may have been dozens of shipments over the years to an LLRW facility, there was only a single scenario written for each of the LLRW facilities that addressed all of the. relevant shipments. The HBPP scenario represents end locations where the fuel segments may currently reside at the site. The process implemented evaluations of the likelihood of the three fuel rod segments being located at each scenario location and classified the scenario categories as either "highly unlikely," 'possible but not likely,"

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"reasonably possible," or "confirmed." The HBPP scenarios were developed for end locations for where the HBPP fuel segments may currently reside.

The following table provides a'sumniary of the HBPP scenarios and the subset events of those scenarios that were addressed by the Project team.

HBPP SCENARIO CATEGORIES Category Title '

-Subset Scenario Events Represented Scenarios Physical HBPP SFP Inspection Locations - 56 1

Inspections HBPP Non-SFP Inspection Locations - 61 1

and Areas on Site.

Low Level Barnwell 1983 Shipments - 3 1

Radioactive 1985 Shipments - I Hanford 1985 Shipments - 17 1

1986 Shipments - 5 Implausible LLRW

'Total Shipments - 238 1*

Other Direct NFS - West Valley

'1969, '1970 & 1971 Shipments I

Shipments

-15 Implausible ODS Total Shipments - 168 1*

Uncontrolled Theft or Diversion N/A I

• One scenario was written to address both the LLRW Facility and ODS implausible scenarios, since the' analysis and discussion is appropriate for both scenario categories.

Once the initial scenarios were' identified, a Project Lead was assigned to more rigorously develop each scenario. The Project Lead followed, where appropriate, the guidance of the standardized scenario description format designed to identify scenario "attributes" - those facts and assumptions supporting or refuting the scenario's plausibility..

The'following'elenments served as' guidance in describing scenarios:

WHAT - What happened? State what event, activity or-action may have taken place that affected the fuel rod segments and/or the pipe container (e.g., SFP clean-up).

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• WHEN - When did the event, activity or action take place? If possible, specify the calendar date, clock time, or associated major evolution (e.g.,

preparations for refueling outage). Refer to the Project Timeline for data on known events.

• WHO - Who performed the action or activity that may have affected the fuel rod segments and/or pipe container? (e.g., fuel handlers) If possible, identify the participants by name, position, and /or company.

EXTENT-How many locations, actions or activities are included in the scenario (e.g., 7x7 fuel assemblies having missing fuel rods or partial fuel rods)?

• WHERE - Where are the fuel rod pieces postulated to be? (e.g., in the SFP, inside a GE 7x7 fuel assembly)

• BASIS - Identify the supporting data for the scenario; (i.e., what information suggests the specific attributes of this scenario are plausible (e.g.,

Dwg. GE77RR3 of a 7X7 fuel assembly shows that there are no locations within the assembly to store fuel rod segments if the assembly is intact)). List the specific relevant documents and interview data.

QUESTIONS, COMMENTS AND ASSUMPTIONS - Identify significant assumptions included in the scenario. Specifically identify if the scenario includes activities or details not explicitly known or not yet verified. Identify questions that will refine the scenario and help to determine if it is plausible.

Scenario Screening For potential scenarios involving LLRW shipments (example: laundry, samples, vendor equipment, dry activated waste, and other surface contaminated items) packaged in unshielded containers, such as drums, LSA boxes, etc., a time versus dose calculation for the fuel rod segments has been developed as a ascreening tool." The "screening tool" was utilized to eliminate the subject LLRW shipments from further consideration due to the low probability that anything shipped as LLRW material in an unshielded container could contain the fuel rod segments. Additionally, material shipped to another licensee containing high activity fuel rods would have been immediately recognized by the receiving facility.

Scenario Preparation and Format A written disposition of each scenario (including implausible scenarios for ODS and LLRW shipments) was prepared and in most cases included the description of the scenario, investigation, analysis of the investigation results, conclusion, and recommendations. Each conclusion section of the scenarios stated and assigned one of four possibility categories for each scenario:

• 'Highly Unlikely" means the event is very improbable.

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" 'Possible, But Not Likely" means the event, while possible, would have a fairly low probability of occurrence.

• "Reasonably Possible" means the event may have occurred.

• "Confirmed" means the event did occur.

Potential scenarios specifically associated with the HBPP Unit 3 SFP and onsite storage locations were addressed by physical inspection. The physical inspection scenarios were not subject to the scenario assessment process, but were documented in a similar manner. Each identified scenario was formally reviewed and approved via signature sign-offs.

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3.0 SPECIAL NUCLEAR MATERIAL CONTROL AND ACCOUNTABILITY This section examines the various form's of special nuclear material (SNM) present at Humboldt Bay Powe'r Plarnt'(HBPP) Unit 3.' The following information is the result of an extensive document search, a thorough physical search inside and outside the spent fuel pool (SFP), and numerous interews with present and former plant employees and contractors to quantify and report on'the SNM inventory at HBPP Unit 3. A Charter waslestablished (Reference 1J to define the scope and purpose of the SNM Inventory, Inspection and Control Project (Project).,

The SNM inventories and evaluations described in this section are considered to yield the 'best possible estimates of current SNM inventory at HBPP. HBPP calculations and accountability records' have been, or are being revised to reflect the quantities and locations of SNM containing materials as discussed herein.

Updated DOE/NRC Forms 741/742 submitted on March' 17, 2005, PG&E Letter HBL-05-007, accurately report the inventory adjustments and total SNM inventory resulting from these evaluations.

SNM and regulatory historical overviews and a detailed evaluation of SNM in its various locations and applications at'HBPP Unit 3 are included. The calculations that set forth the amount of SNM in fuel fragments and quantify the SNM in each of the plant areas containing SNM waste are also discussed. 'A table summarizing the status, locatiohn-'and quan'tities of SNM "stranded" at HBPP primarily from'General Electric'Typ'e'l, stainless steel-clad fuel failures (see discussion below) is provided.' Reporting'requirements, a'discussion of SNM Material Control and Accountability procedures, and a reference list complete the material presented.

3.1 HISTORY 3.1.1 SNM HISTORY SNM was delivered 'to HBPP Unit 3 in-the form of nuclear fuel, nuclear sources, and nuclear insirumentation'during its operating life, from the early 1960s through 1976. The Project examined an extensive amount of plant documentation and othe rec6ords from' this period and 'has found adequate and traceable documents for the receipt of this SNM. Current regulations requirethat onsite SNM be accounted fo'r'and'the accounting periodically reported to 'regulatory agencies. During the operating life of HBPP Unit 3, periodic regulatory audits/inspections vere performed to assess th a'dequacy' of liceisee compliance wiihsaccounting requirements.

Nuclear Fuel There are 390 fuel assemblies with zircaloy-clad fuel rods (zircaloy-clad fuel assemblies or zircaloy assemblies) located in the HBPP SFP. An 3-1

an-examination of activities surrounding control of SNM for zircaloy-clad fuel assemblies is included in this report. The examination included all zircaloy-clad assemblies remaining onsite, including those assemblies that have been modified, reconstituted, or otherwise altered. The review indicates that the control and accountability of SNM in assemblies' located onsite, both modified and unaltered, was satisfactory and no revision or recalculation of SNM contained in the zircaloy assemblies is necessary.

In addition to the onsite zircaloy assemblies, shipment documentation associated with reprocessed fuel assemblies was examined to verify SNM accounting. Further, HBPP engaged in a fuel buy-back program where unirradiated fuel was sold back to the fuel vendor. The SNM accounting for this fuel buy-back activity is also examined in this report.

Fuel Fragments At the time that HBPP Unit 3 entered commercial service in 1963, its nuclear fuel assemblies utilized stainless steel as the fuel rod cladding.

HBPP completed its transition to zircaloy assemblies in 1969. The stainless steel-clad fuel experienced gross cladding failures. Other early GE boiling water reactor plants (Dresden, Big Rock Point, etc.) were also experiencing fuel cladding failures with stainless steel-clad fuel. These failures resulted in cracking and stress failures of portions of fuel rod cladding. The failures were severe enough that active fuel (and thus SNM) was released from its cladding to various operating environments.

Complicating matters further, the fuel separated from the fuel assemblies with stainless steel-clad fuel rods (fuel fragments) was never precisely quantified and the assemblies were subsequently shipped offsite for reprocessing. These conditions make a precise calculation of the amount of SNM in fuel fragments lost from stainless steel-clad fuel failures impossible. Records and data that help in quantifying the released SNM for these stainless steel-clad fuel failures are limited to several reports of fuel inspections performed in the 1960s and reports detailing stainless steel-clad fuel fragments found during cleanup activities. The Project has reviewed these stainless steel-clad fuel inspection reports and determined that: (1) the visual inspections focused on fuel rods that are located on the periphery of the assembly, (2) some of the inspection results were duplicative (a subsequent inspection identifying a fragment shown on an earlier report, etc.), and (3) approximately one third of the assemblies do not appear to have been inspected or the records for these inspections are unavailable.

3-2

Fuel Rod Segments In November 2003, work in the SFP was stopped while the implications of identifying fuel fragments within the SFP were reviewed. In early 2004, a reassessment of the SNM inventory began. In late June 2004, during document reviews as part of the reassessment, a discrepancy involving assembly A-49 and the cutting and disposition of one of its rods was discovered.

In September 1968, a portion of one fuel rod in a stainless steel-clad assembly (assembly ID # A-49) was cut with the intent of sending three 18-inch segments offsite for study. The study was ultimately cancelled and the three segments remained onsite, with their last documented location - in 1968 - being the SFP. Assembly A-49 was sent for reprocessing in 1969 but there are no records that the cut rod segments were sent with the assembly. The three segments from the A-49 fuel assembly are referred to as fuel segments in this report.

SNM Waste The SNM released from the'fuel cladding failures was distributed in various operating environments. These environments included the reactor coolant system, reactor vessel, condensate demineralizers, SFP, reactor cleanup demineralizers, and SFP demineralizers. Subsequent cleanup activities included vacuuming of waste material from the floor of the SFP on several occasions, vacuuming of the reactor vessel lower core support plate, and adjunct spent fuel water purification/clarification systems. The filters, bags, and demineralizers used for these cleanup activities contained quantities of SNM. SNM waste was also appropriately shipped offsite as part of radwaste shipments (these SNM quantities are documented on DOE/NRC/ Atomic Energy Commission (AEC) transaction forms and plant shipping records, and may be readily totaled).

The task of quantifying/accounting for the stranded SNM was performed by using a combination of radiological survey data and engineering assumptions. These calculations have inherent uncertainties in that the survey data is limited and necessitated assumptions regarding survey geometry, material quantity and density, and isotopic composition.

Assumptions that are required to perform the SNM calculations introduce significant uncertainties, rendering a precise material balance extremely difficult.

The calculations referenced or performed in this report provide a reasonable estimate of SNM residing at HBPP in the form of fuel fragments and SNM waste.

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3.1.2 REGULATORY HISTORY HBPP Unit 3 was a General Electric natural circulation boiling water reactor operated by PG&E. The AEC issued Provisional Operating License DPR-7 for Unit 3 in August 1963. Commercial operation began in August 1963.

Unit 3 was initially licensed to operate at a maximum powerlevel of 165 MWt (50 MWe). In 1965, the AEC issued a license amendment authorizing operation at a maximum power level of 240 MWt (70 MWe).

The initial license authorized use of fuel assemblies containing stainless-steel-clad fuel rods. In 1965, a license amendment was issued authorizing use of zircaloy clad fuel rods. The initial license also authorized PG&E to possess 780 kg as contained uranium-235 (increased to 1,000 kg in 1965) and a smaller amount of SNM in the form of ionization chambers and startup neutron sources.

In 1956, 10 CFR 70 was promulgated requiring licensees to keep records showing the receipt, inventory, and transfer of SNM in their possession, and to report any loss, other than normal operating loss, of SNM. This regulation did not include physical inventory accountability requirements for Part 50 licensees. PG&E complied with this regulation and subsequent revisions following issuance of their operating license in 1963.

In 1967, 10 CFR 70 was revised to require SNM accountability at commercial nuclear power plants. The revised regulation required, among other things, the licensee to "establish and maintain written material control and accounting procedures which are sufficient to enable the licensee to account for the special nuclear material in his possession under license." HBPP SNM procedures complied with the fuel accountability requirements of this regulation on a fuel assembly basis.

The procedures did not address accountability of smaller quantities of fuel in the form of individual fuel rods or fuel fragments. The procedures did, however, provide specific accountability requirements for non-fuel SNM containing items, such as incore strings containing ion chambers, excore fission chambers, and startup sources. Plant procedures for SNM accountability remained much the same until mid-2004, when they were revised to include control and accountability of fuel in the form of fuel rod segments and fuel fragments.

In 2002, the recordkeeping requirements for SNM were transferred from 10 CFR 70 to 10 CFR 74. PG&E currently complies with 10 CFR 74 for the SNM in its possession.

From plant startup until 1974, security activities at HBPP were carried out by plant personnel as directed by plant management. In 1973, security 3-4

regulations were codified in 10 CFR 73. In 1974, PG&E developed and implemented a security systeem and program at HBPP that met the requirements of the 'new regulation.

On July 2, 1976, Unit 3 was shutdown for annual refueling and to perform

-seismic modifications. In' June'1983, PG&E announced its intention to decommission the unit based on economic analyses that showed that completing the seismic as well as other upgrades (e.g., Three Mile Island) necessary for restarting Unit 3 would not be economical.

PG&E opted to place Unit 3 into the' custodial SAFSTOR mode. The NRC approved the SAFSTOR plan on.July 19, 1988, and amended the operating license to a possess-but-not-operate license that expires on November 9, 2015.

The HBPP onsite SNM has been subject to periodic accountability per established plant procedures. 'This accounting is typically a verification of the location of onsite SNM in.spent fuel in the'SFP and unirradiated incore instrumentation and fission 'chambers stored in the refueling building.

Note that the verification of SNM in spent fuel located in the SFP is not required if the SFP cover has remained in place over the SFP.

,When Unit 3 entered SAFSTOR in 1988, PG&E established an NRC-approved Physical Security Plan that complied with those sections of 10 CFR 73 applicable to a decommissioned facility. Following the -

September 11, 2001, attacks on Washington, DC, and New York City, HBPP upgraded security plans and programs at HBPP in accordance with NRC Security Orders.

Periodic AEC/NRC inspections and audits, as well as internal PG&E audits, of the SNM accountability and inventory process at HBPP did not identify any problems 'related to fuel fragments (Reference 23), even though the AEC and PG&E personnel were aware of the presence of fuel fragments in the SFP (Reference 24). PG&E does not know why the insp'ectors and auditors did not identify SNM accountability and inventory inaccuracies related to fuel fragments. However, one apparent reason that the auditors did not look for, shortcomings in procedures was that the audits were compliance based. Thus, this failure to identify a problem at that time can be attributed, iri part,' to the lack of specific regulatory and industry guidelines for accountability of fuel quantities less than that contained in-an 'entire'fuel assembly. It should be noted that industry guidance and practice was to account for SNM on a fuel assembly basis from the time AEC regulations were first promulgated requiring SNM accountability in early 1967. tThis 1967 regulation required, among other things, the licensee to "establish and maintain written material control and accounting procedures which are sufficient to enable the licensee to account for the special nuclear material in his possession under license."

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_11 n Prior to issuance of this regulation, HBPP SNM procedures were written to comply with the SNM requirements contained in 10 CFR 70 issued in 1956 and the operating license issued in 1963.

In October 1974, ANSI Standard N15.8-1974 (Reference 25), was issued, which was endorsed by NRC Regulatory Guide (RG) 5.29 (Reference 26).

The standard states in Section 6.1 that "the basic unit for control of nuclear material shall be the nuclear fuel assembly." Section 6.1 also states that "Nuclear material contained in fuel elements (defined as the smallest structurally discrete part of a fuel assembly, such as a fuel rod or fuel pin), not part of an assembly, shall be separately identified on all material control records." RG 5.29, Revision 1, endorsing ANSI N15.8-1974, was not issued until June 1975, well after the time fuel fragments were produced, collected, and stored at HBPP1. Therefore, PG&E believes that it may have been reasonable for plant personnel to not include fuel fragments in the SNM inventory. Certainly the practice followed was not unreasonable. Similarly, it may also have been reasonable for AEC/NRC and PG&E inspectors and auditors to not identify problems related to accountability of fuel fragments. Although regulations have not changed, current NRC expectations are for licensees to account for fuel fragments and any SNM less than an assembly in the SNM inventory.

3.2 FUEL At the time that HBPP Unit 3 entered commercial service in 1963, its nuclear fuel assemblies utilized stainless steel as the fuel cladding. These stainless steel-clad fuel assemblies are described as Type I or Type A assemblies.

In the mid-late 1960s, HBPP Unit 3 began transitioning to zirconium alloy clad fuel - known as zircaloy-clad fuel. Core loadings comprised of both stainless steel-clad fuel and zircaloy-clad fuel began in December 1965 and HBPP cores began exclusively using zircaloy-clad fuel assemblies in July 1969. Zircaloy-clad assemblies were used in all subsequent core loads for the remainder of plant operating life through 1976.

With the use of zircaloy-clad fuel, the gross cladding failures were mitigated.

While fuel failures occurred with zircaloy-clad fuel, these failures did not involve release of active fuel to plant systems - only fission gases, some fuel 'wash-out,'

and tramp uranium, none of which contain significant quantities of SNM.

Fuel inspection reports for zircaloy-clad fuel were reviewed. Several fuel assemblies were inspected utilizing eddy current based non-destructive testing.

No gross fuel failures were identified. Thus, these inspections confirm that fuel

' PG&E did not commit to compliance with Regulatory Guide 5.29 and did not incorporate the provisions of ANSI N15.8-1974 into the SNM control and accountability procedures at HBPP.

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rods in these zircaloy-clad assemblies were not subject to the gross cladding failures experienced with Type 1, stainless steel-clad fuel.

In total, HBPP received 704 fuel assemblies. Of these 704, 44 have been returned to their manufacturer prior tirradiation, 270 have been shipped offsite to a reprocessing facility, and 390 remain at HBPP.

3.2.1 ASSEMBLIES

'For purposes of this report, fuel assemblies are grouped to reflect their operating history. Each group has'defining characteristics. The fuel assembly groups and their defining characteristics are presented below:

Unmodified Assemblies - Assemblies that contain their original as-received complement of fuel.'- The'only changes to the SNM content of these unmodified assemblies are due to burnup and decay. These

' assemblies have not been subjected to any physical disassembly and

- retain their original as-manufactured physical characteristics. This group contains 361 fuel assemblies.

Modified Assemblies - Assenmblies that have been subject to any activities outside of visual inspection and/or no longer'contain their original as-received complement of fuel.' These'assemblies may have been subject to one or more of the following activities: reconstitution, removal of rods for offsite shipment to6GE, installation of special high enrichment rods installed for a GE te'st program, and fuel assemblies that have had their structural stability compromised and are maintained in their desired configuration by use of external structural support devices. This group contains 28 fuel assemblies.

UD-6N Assembly - This assembly is treated as a special case. Following operation in two core cycles', UD-6N inadvertently became detached from fuel handling equipment and fell approximately 6 feet to the SFP floor.

The UD-6N assembly structural 'configuration was lost. The assembly retains its original SNM. This group contains one fuel assembly.

Reprocessed Assemblies'-'lrradi ted assemblies that were shipped offsite to Nuclear Fuel Services/West Valley for: reprocessing. This group contains 270 fuel assemblies, and includes the total site complement of stainless steel-clad fuel assemblies.

Returned Assemblies -Assemblies delivered to HBPP, but returned to the fuel vendor for financial compensation.2 Forty four Exxon assemblies, 2 In some cases, fuel Inspection findings and/orother quality issues necessitated return of the unirradiated fuel assembly to its vendor. The assembly was then returned to HBPP. Instances where a fuel assembly was returned to the vendor (prior to Irradiation) and subsequently returned to the site are not defined as a returned assembly.

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XD-01 through XD-44, were delivered to HBPP, but HBPP ceased reactor operation subsequent to the shipment receipt. The unirradiated assemblies were later returned to Exxon as part of a buy back effort. This group contains 44 fuel assemblies.

3.2.1.1 Unmodified Assemblies HBPP currently has a total of 390 fuel assemblies located in the Unit 3 SFP - 389 assemblies encased in Boral Cans and one assembly (UD-6N) in a stainless steel container. SNM content of the assemblies, as delivered, is accurately reflected in HBPP Nuclear Material Transaction Reports and Material Status Reports.

Investigation by HBPP and the Project indicates that 361 of these assemblies are unmodified.

Since these assemblies have never been physically disassembled, damaged, or altered, the SNM content of these assemblies is their original quantity of SNM as adjusted for burnup and decay.

Existing plant records - in particular, PG&E letter to US DOE dated October 27, 1986, providing a listing of discharge fuel cycle numbers for all nuclear fuel at HBPP Unit 3 (Reference 15) and a memorandum dated March 12, 1993, "Special Nuclear Material Fuel Assembly Accountability for Humboldt Bay Unit 3" (Reference 16) - provide the information needed to determine SNM in the fuel assemblies. For each fuel assembly, Reference 16 gives a receipt date, beginning composition, discharge date, and the uranium and plutonium content at the time of plant shutdown in July 1976.

Section 4.1 of PG&E Calculation NX-287 (Reference 4) examined diverse documentation related to fuel bumup to check the accuracy of the Reference 15 and 16 accountability reports. Burnup values used in the reports were found to be accurate.

In addition, Section 4.5 of PG&E Calculation NX-287 examined the assumptions used for decay of Pu241 - the only isotope that decays quickly enough to have any appreciable affect on SNM calculations for the shutdown HBPP Unit 3. It was determined that the original data used in SNM quantification used a single discharge date for all 390 HBPP assemblies, and resulted in over-estimating the onsite SNM. This discrepancy was corrected and the fuel assembly SNM quantities were corrected to accurately reflect the discharge date for each individual fuel assembly. The corrected quantities were first reported in the DOE/NRC Form 741 and 742 reports for the period ending September 30, 2004, submitted on November 30, 2004 (Reference 18).

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Extensive plant record review identified historical SFP maps and core-loading maps that track the unmodified fuel assembly locations during their operating lifetime and their storage as spent fuel.

PG&E Calculation NX-287 validates the SNM content (accountability) for all onsite fuel assemblies, including the 361 unmodified assemblies. The physical SFP inventory performed on July 25, 2004, verified the locations (control) of these assemblies..

3.2.1.2 Modified Assemblies Three hundred ninety zircaloy-clad assemblies remain at HBPP and all are located in the SFP. Investigation by HBPP and the Project (Referenrce 13) has determined that 28 of the assemblies were subject to modification' at HBPP.

Modified assemblie's are'those that have undergone any physical work or alteration, whether or not the work or alteration affected the quantity of SNM contained in the assembly. Modified fuel assemblies include those with physical damage due to failed disassembly efforts (sheared top end plate studs, missing upper/lower end plugs, fuel rod unscrewed from tie plate, etc.) even if some of these conditions would not be expected to affect the quantity of SNM in an assembly. Modification to an assembly also include activities that affect the SNM content of the assembly, including removal'of a po6rtion of the' assembly SNM (e.g., a fuel rod), removal and replacement of the SNM, removal of SNM to accommodate test rods, etc.

These assemblies were subject to tests and experiments involving removal and shipment offsite of a total of 66 fuel rods from various fuel assemblies. Other activities included fuel assembly reconstitution; installation of boron surveillance rods; and installation of four high enrichment rods.

Extensive reviews of plant records indicate that the SNM contained in the zircaloy-clad assemblies was accurately characterized (given the existing technology) and that the SNM changes associated with the above-described activities were properly reflected in SNM accountability records.:

In addition to the 66 fuel rods shipped offsite to General Electric (GE), a shipment of 13 unirradiated fuel rods has also been reviewed. These'13 rods we're removed from nine specially designed assemblies to accommodate the boron surveillance rods and the high enrichment rods. The Materials Transaction Report 3-9

and the Materials Status Summary reports were reviewed and properly account for the shipment of 13 unirradiated rods.

The Project completed a detailed review of the history of changes to the 28 reconstituted or modified assemblies to reverify SNM accountability for these assemblies. This review confirms and expands upon the examination of modified assemblies included in PG&E Calculation NX-287 (Reference 4). The reverification is documented in the Project Report, uEngineeting Review of Control and Accountability of Modified Fuel Assemblies at Humboldt Bay Power Plant' (Reference 13), which is being submitted as a stand-alone report concurrently with this report.

Modification to these 28 assemblies is well-documented and ultimately involved removal and shipment offsite of 66 fuel rods from 12 of the assemblies. SNM Accountability Records properly reflect this net reduction in SNM resident at HBPP.

The periodic physical SFP inventory verifies the physical location of these assemblies.

Additional review of videos of these modified fuel assemblies were performed in January 2005 to provide further clarification regarding assembly configuration.

Based on these reviews, it is concluded that the current fuel assembly configuration and SNM content documentation properly reflects all changes made to these 28 assemblies over the years.

3.2.1.3 UD-6N Assembly UD-6N is the only assembly that has lost its physical configuration such that the assembly must have a specialized container to allow storage in a typical SFP storage cell.

In June 1975, UD-6N was mishandled during fuel movement and the structural integrity of the assembly was compromised to the extent that UD-6N was placed in a custom container for long-term storage. This custom container also held several stainless steel-clad fuel fragments that were collected during earlier SFP cleanups in the 1980s. UD-6N history was verified in Section 10.3.3 of PG&E Calculation NX-287 (Reference 4). During the recent SFP work, the UD-6N container contents were removed, a new UD-6N container procured, and the UD-6N assembly placed in the new container. All of the original UD-6N fuel rods are enclosed in the new UD-6N container-no Type I, stainless steel-clad fuel fragments are in the new container. The Type I, stainless steel-clad fragments found in the old UD-6N container were moved to 3-10

Fuel Fragment Container (FFC) Number 1 (Reference 5). Project Report "FuelAssembly iJD-6N,"(Reference 17) provides a detailed chronology of activities a's'sociated with assembly UD-6N.

Project document review.indicates the SNM content of UD-6N has accuratelyreflected changes to the assembly SNM content due to burnup and decay.'..

3.2.1.4 Reprocessed Assemblies Fifteen shipments of spent nuclear fuel were made from May 1969 to June 1971. Each of the 15 shipment contained 18 assemblies.

The entire site inventory of 189 stainless steel-clad fuel assemblies were reprocessed along with 81 zircaloy clad assemblies.

HBPP records include.a listing of the bumup for each of the stainless steel-clad fuel assemblies. This bumup data enables HBPP to accurately determine the SNM quantities for each fully intact stainless steel-clad fuel assem'bly at the time it was shipped from the plant for reprocessing.

Shipment SNM content and AEC/NRC required shipment documentation were found for all reprocessing shipments -

Material Transfer Fomi (AEC Form 388, later DOE/NRC Form 741) and a properly updated Material Status Report (AEC Form 578, later DOE/NRC Form 742). However, the shipment SNM values were based on the full complement of assembly SNM, adjusted for bumup. The Type I, stainless steel assemblies were known to have experienced cladding failure resultingin the separation of some of the assembly SNMfrom its parent assembly. Thus, the SNM content of the reprocessed stainless steel-clad assemblies with missing fragments Was not'correct; although an accurate estimation of SNM missing from any given stainless steel-clad assembly was impossible without fully disassembling each fuel assembly to accurately determine' how much active fuel was missing.

Subsequent to'receipt of -the fuel, Nuclear Fuel Services/West Valley provided receipt SNM values, ostensibly reflecting SNM recovered in the reprocessing effort. These values were slightly different'than the HBPP shipment SNM values. The differences encountered in all 15-shipments were.summe'd'and the totals entered into the net 'semi-annual Material Status Report.

However, the values'for elemental Plutonium were not summed correctly. Note that the incorrect values for elemental Plutonium do not affect ongoing site SNM totals, as the fuel had already been shipped offsite, and its inventory was 'off the books.' PG&E is 3-11

'X u evaluating the error and may issue a revised Material Status Report reflecting the correct elemental Plutonium values.

Documentation from Nuclear Fuel Services (NFS) in West Valley, New York (the reprocessing facility) includes the SNM that was realized during the reprocessing of HBPP fuel. Acceptance criteria for the reprocessing effort extended to greater than or equal to 98 percent of assembly SNM weights3. Thus, the errorsin quantification of the SNM realized during reprocessing, combined with the sizable number of assemblies (189) that were reprocessed renders the reprocessing data unusable for precisely determining the SNM remaining at HBPP.

3.2.1.5 Returned Assemblies In April 1976, HBPP completed receipt of 44 Exxon Type XD fuel assemblies. On July 2, 1976, Unit 3 was shutdown for annual refueling and to perform seismic modifications. The Exxon XD assemblies were intended for Cycle 12 operation, and were loaded in the reactor vessel from March 1977 through January 1984. In June 1983, PG&E announced its intention to decommission the unit. PG&E opted to place Unit 3 into the custodial SAFSTOR mode. The NRC approved the SAFSTOR plan in July 1988 and amended the operating license to a possess-but-not-operate license that expires on November 9, 2015.

PG&E expressed a desire to recoup some of the costs for this XD fuel via a vendor buy-back program. As part of the program, a sample of eight fuel pellets from one of the XD assemblies was provided to Battelle-Northwest in December 1984 to verify the XD fuel had not become irradiated while in residence in the HBPP reactor vessel. The fuel sample was found acceptable and the fuel was eventually disassembled and the fuel rods returned to Exxon Nuclear in May 1985.

SNM Accountability documents for these transactions were reviewed and one problem identified. The Nuclear Material Transaction Report (DOE/NRC Form 741) and the Material Balance Report (DOE/NRC Form 742) documents associated with the sample shipment to Battelle-Northwest were reviewed and found acceptable. However, the Material Transaction Report for the return of the XD fuel erroneously cited the SNM content for the 44 Exxon Type XC assemblies delivered to HBPP in April 1975.

The Material Balance Report correctly shows the XD fuel SNM as 3On a per-assembly basis, 2 percent of an average stainless steel-clad assembly SNM weight would equate to over 1.2 kg Uranium or over 50 equivalent inches of fuel.

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being shipped offsite. A revised DOE/NRC Form 741 for the XD fuel shipment to Exxon Nuclear will be submitted to correct the error.

3.2.2 FRAGMENTS This section examines SNM contained in fuel that has become separated from its original application and has'been subsequently located, collected, and characterized such that a precise estimate of the SNM is possible or.

has'been com'pleted.

Note that the SNM that ha's become separated from its original application is comprised of (1) Type I, stainless' steel-clad fuel that became separated from its parent fuel assembly and migrated to various plant locations, and (2) the three eighteen inchA-49 fuel rod segments and the remnants from the A-49 cutting process'. The A-49 fuel rod segments will be evaluated in

'Section 3.2.3 of this Final Reeport. '

Definitions have been provided in the Section 2.3 of this Final Report.

Terms and their definitioris that are germane to' this discussion are reproduced here for convenience:

• Fuel Assembly: A fuel assembly is a group of fuel rods (also called a bundle) held together in a specific geometry for placement into the reactor core. Most HBPP fuel assemblies are intact, but some are not intact, and some fuel assemblies do not have a full comhplement of fuel rods. The fuel in the fuel rods contains SNM.

• Fuel Segments: Fuel segments are the three cut pieces of fuel rod from assembly A-49. The'fuel in fuel segments contains SNM.

• Fuel Fragment: A fuel fragment is a clad or unclad portion of a fuel rod, including pellets or portions of pellets that have a measurable dimension nominally greater than % inch. Cladding without fuel is irradiated hardwar'e,not a fuel fragment. The fuel in fuel fragments contains SNM.-

SNM Waste-SNM 'vaste is'waste that contains SNM that originated from either fuel failurds'diiring plant operations or from fuel handling.

SNM waste is waste that is collectible (i.e., not adhered to a component surface).: SNM waste may be greater than Class C waste.

SNM waste is not'considered to be fuel.'

NOTE: A demarcation of % inch separates SNM Waste from Fuel Fragments. This particle size represents the lower bound of discrete pieces that can be picked up by fuel handling tools, characterized, and placed in specialized containers. SNM Waste includes pieces that are 3-13

smaller than 1/4 inch and includes sediment/debris layers on the SFP floor, SFP interim storage container, cleanup demineralizers, and filters.

Fuel used in the first several cores at HBPP Unit 3 had stainless steel as the cladding material. After a brief operating period, the cladding exhibited failures. Other early GE boiling water reactor plants (Dresden, Big Rock Point, etc.) were also experiencing fuel cladding failures. These failures were severe enough to result in SNM (in the form of fuel) being released to the reactor coolant system during plant operation and further released to the SFP during assembly dechanneling, fuel washing procedures, and subsequent fuel moves in the SFP.

Before being installed in the reactor, each fuel assembly was placed in a close-fitting topless, bottomless, zirconium box to ensure predictable coolant flow through the fuel assembly during operation. These "flow channels" (usually just called 'channels") were removed from each fuel assembly after the assembly was moved from the reactor to the SFP. The design of the channels limited the loss of broken fuel rods4 in the reactor, although it is possible that some fuel fragments may have passed through the assembly opening if the fuel had been severely damaged.

The most likely time for such fragments to escape from the fuel assembly was when the channel was removed to inspect the assembly in the SFP.

Another occasion for such pieces to escape would have been when an assembly was cleaned in the 'fuel washer." The fuel washer, located in the SFP, was designed with a "pellet catcher" - a container designed to catch and retain fuel fragments and debris dislodged from the fuel assembly during the washing operation. The "pellet catcher" was used subsequent to the initial fuel washing operations which demonstrated the need for this device.

The earliest documentation of the cladding failure problems are fuel inspection reports prepared in the mid-1960s. Section 10.3.2 of PG&E Calculation NX-287 (Reference 4) examined these early fuel inspection reports. The reports provide summarized visual results for Type I, stainless steel-clad fuel. The results from a total of five documents concerning fuel inspection during this period were examined and the inspection results compiled into a listing of corroded/spalled fuel rods, distorted/bowed fuel rods, bulging fuel rods, bent fuel rods, cracked/broken fuel rods, and fuel rods that are cracked and fragments missing. Thus, fuel fragments were known to exist at this point in HBPP's operating history.

4 From GE drawing #197E923, the cladding Outside Dimension is 0.463 inches, and from GE drawing

1. 612D905, the opening at the top and bottom of the assembly would not pass an object more than 0.448 inches in diameter.

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Zircaloy clad fuel was subjected to vendor eddy current tests. The testing identified some failed zircaloy clad rods; however, none of the failures was severe enough to cause active fuel to become separated from its parent assembly. Further, primary system specific activity levels were significantly lower during operation with zircaloy clad fuel. The eddy current testing and the operating history with zircaloy clad fuel allows for the reasonable assumption that fuel that has left its parent fuel assembly bundle due to cladding failures is exclusively from stainless qteel-clad fuel, and that the fuel fragments and SNM waste resulting from these fuel failures dates to the 1960s. All Type I, stainless steel-clad fuel assemblies were shipped offsite for reprocessing prior to July 1971. No stainless steel-clad fuel assemblies now reside at HBPP.

The presence of fuel fragments became apparent in the mid-sixties.

Internal plant correspondence entitled "Fuel Accountability During Fuel Inspections," dated July 20,-1966, instructed the fuel inspectors to estimate as accurately as possible the total number of rods or portions of rods that are missing. The July 20 memo also stated that PG&E is required to account for all of the uranium onsite at HBPP, and an accurate estimation of the fragments or portions of fuel rods that are missing is necessary.

Finally, the July 20 memo stated that all fuel moves should be entered in the control operators log in order to insure that there is a permanent record kept. The operators' logs for this period in HBPP history were not found by the Project or no longer exist. The SNM Accounting Records from these earlier days of plant operation were also not found by the Project or no longer exist.' Thus, the Project was not able to confirm the extent of SNM Accountability processes/practices during the timeframe that stainless steel-clad fuel was onsite at HBPP.

In 1976, during a cleanup campaign for the HBPP SFP, there were three instances where SFP activities unexpectedly encountered a fuel element (two pieces of a fuel rod) or fuel pellet. In each instance, an SNM accountability record was generated and the conditions surrounding the discovery were documented in the accountability record. In all three cases, the SNM was believed to be part of Type I fuel. The three accountability records were never subsequently updated, and do not contain information as to their SNM content. ;The SNM accountability records of interest include three records - 'Fuel Pellet,' 'Fuel Pellets,' and

'Fuel Element.' The 'Fuel Pellet' and 'Fuel Pellets' accountability record entries are evaluated first, followed by evaluation of the 'Fuel Element' entries.

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Pellets In Vacuum Bags The 'Fuel Pellet' SNM Accountability Record has two entries. The first is dated June 3, 1976, and states: 'Found 1 fuel pellet on tri pod in SFP.

Moved to pig in hot lab. (Type I Fuel).' The second entry is dated 6/7/76 and states 'Transferred from hotlab to vaccuume (sic) cleaner bag in south east corner of pool along with other pellets that were vacuumed up from spent fuel pool.'

The 'Fuel Pellets' SNM Accountability Record has a single entry dated June 4, 1976, that states: 'During vacuuming (sic) of the SFP, fuel pellets were picked up in the bag of the vaccuume cleaner. The pellets are probably from the Type I fuel. The bag is hung on the side of the pool in the south east corner.'

A plant temporary procedure utilized in 1976 entitled 'Use of Underwater Vacuum System in Spent Fuel Poor describes the methodology for vacuuming the SFP and a description of the vacuum system. The procedure states '...The sediments are collected in a filter tank. The tank is lined with a woven Saran mesh. There is a Dynel fabric bag liner that serves as the actual filter media support. The filter bag will be precoated with the diatomaceous earth...When the bag is full and/or the filtering rate decreases below the minimum flow rate, the bag liner will be removed and replaced with a new bag.' The procedure further states, 'The underwater vacuum system has a large mesh screen inlet strainer (Y4 inch by Y4 inch screen opening) ahead of the underwaterpump and vacuum filter. The inlet screen serves two purposes: It collects large pieces of material and allows the vacuum to be used to pick up assorted small pieces of material such as cap screws.'

A second plant temporary procedure for SFP cleanup that was utilized in 1983 also included a figure showing the vacuum equipment setup. The figure indicates that the vacuum system had a % inch strainer on the suction inlet of the vacuum.

Information contained in the temporary procedures for the 1976 vacuuming campaign provides reasonable evidence that the vacuum system utilized an inlet strainer. Thus, fuel fragments could not have been deposited into the vacuum filter bags. However, SNM waste (being smaller than 1/4 inch by % inch) could have made its way through the inlet strainer and into a vacuum filter bag. Bolstering this evidence is a personnel interview conducted on November 22, 2004, with the individual in charge of the vacuum efforts during the 1976 SFP clean-up campaign.

He stated unequivocally that the vacuum system would not have been capable of passing fuel fragments through to the vacuum filter bags and that to the best of his knowledge no one ever put pellets in a vacuum bag.

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Based on the various vacuum system configurations previously discussed, it may be reasonably concluded that the fuel fragments were not vacuumed directly into a vacuum filter bag. Accordingly, it can be hypothesized that either:. (1)'a Vacuum filter bag was used to hold and store the fuel fragments, or (2) operation of the vacuum system caused fuel fragments to lodge on the strainer of the vacuum and were subsequently stored in a vacuum filter bag, or (3) the vacuum filter bags contained SNM waste and this waste was described as fuel pellets.

The pdrson who entered the information regarding fuel pellets in the SNM accountability sheets was interviewed on December 7, 2004. While he had no recollection of the entries or events surrounding the entries, he did believe the handwriting was his. Regarding the 'pellet in the pig' entry, he stated that he had 'no recollection of procedure details...still don't remember placing anything in a pig - but having written it down, seems right.' When asked if he had any memory at all concerning storing fragments/pellets he stated that he did not. With respect to the placing of pellets in a vacuum bag, the individual stated that 'if I wrote stuff in logs, I believe we did it. We just wrote out what we did, and let things sort out.

Vacuum bag - possible but I didn't witness it.'

In summary, it is believed that the vacuum bags from 1976 contained SNM waste as it is defined for the Project. It does not appear that actual fuel pellets were vacuumed into vacuum bags, nor does it appear reasonable to believe that pellets were placed in vacuum bags hung off the side of the SFP. See interview of November 22, 2004. If indeed a pellet or pellets were placed in vacuum bags in 1976, those bags were in turn opened and vacuumed again (with a strainer to keep out pellets) in 1985-86, as described below.

A steno pad containing lo'g entries for activities associated with cleanup of the SFP in 1985-1986 was identified by the Project document search efforts. The log describes SFP cleanup efforts in 1986 that included vacuuming the contents of the so-called 'Serpa' vacuum bags from 1976 looking for fuel fragments. The log does not indicate any fuel was found.

Ultimately the contents of the vacuum bags were packaged and shipped offsite as waste.

Thus it appears that any SNM contained in the vacuum filter bags was not in the form of fuel fragments and was most likely SNM waste. The

-contents of the filter bags werexyerified to be free of fuel fragments during the SFP cleanup efforts in 1986. Ultimately, the contents were shipped offsite as radwaste..

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1*1I Fuel Element The 'Fuel Element' SNM Accountability Record has two entries. The first is dated June 4, 1976, and states 'During cleanup of spent fuel pool and pickup of UD-6N, two pieces of a fuel rod were found in the SFP. It is reasonable to assume that the pieces belong to Type I fuel that failed in 19 and has since been sent off site. It is reasonable to assume that the fuel rod does not belong to UD-6N as 5 loose fuel rods werelocated in the vicinity of UD-6N and an inspection of the top of UD-6N with an underwater TV camera revealed only 5 vacant spaces in the fuel assembly.' The second entry is dated August 14, 1976, and states

'Transfered (sic) elements from GE inspection stand to SFP-30. They are now in the can in SFP-30 containing 5 rods from UD-6N.'

An October 19, 1978, report titled 'Assembly # UD6N (fuel Ass'y) Report on Damage to UD6N' addresses the construction of a box to hold the UD-6N fuel assembly and recommendation for moving UD-6N and the loose rods to the box for long-term storage. A plant temporary procedure dated August 20, 1983, addresses the transfer of UD-6N and the loose rods in a can to a specifically designed storage box. The contents of the UD-6N box are documented in an undated two page hand written note.

The two fragments were verified present, measured and otherwise characterized, and placed in specially designed fuel fragment containers during the most recent SFP cleanup efforts of 2004-2005. These activities are documented and video records of the actions taken are available.

It is clear that fuel fragments discovered during the course of SFP activities in the 1960s and 1970s were not routinely documented as SNM containing items or tracked via plant procedures in place for fuel assemblies and non-fuel SNM in sources, fission chambers, or incore detector ion chambers. Internal plant memoranda state that fuel fragments should be consolidated in the SFP 'garbage can', later referred to as the central storage container. Anecdotal evidence from interviews suggests that the intent was to ship the SFP central storage container to Nuclear Fuel ServicesNVest Valley for reprocessing.

A full evaluation of the state of the Special Nuclear Material Control and Accountability program at HBPP during its early years of operation is impossible because documents that likely contained important SNM information (operator logs and SNM accountability ledger books) were not found during the document search or no longer exist. Documentation that was found, combined with information from personnel interviews, indicates that physical accountability of SNM in the SFP was acceptable inasmuch as the fuel fragments or pellets were consolidated in the central storage container.

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The Project review did not find evidence of any attempt to quantify the SNM in fragments or pellets'as they were found, nor does any evidence indicate the SNM content of the central storage container was tracked.

Again', the Project did 'not identify any programmatic requirements related to fuel fragments or fuel pellets, except the guidance to consolidate the material in the SFP central storage container.

When physical work in the SFP began in July 2004, fuel fragments were cataloged and tracked from the time each'was identified for accountability purposes. HBPP Temporary Procedure TP 2004-07 (Reference 9) governed initial identification and assessment of fuel fragments, movement of the fragments, and documented each move and the end location of the fragment as it was transferred to and from temporary storage locations in the SFP.F'TP 2004-08 (Reference 10) governed the evaluation of physical characteristics of the fuel fragments and loading of the fragments into permanent storage containers (Reference 22). Video recordings were used to assist in determining physical characteristics.

Data sheets from TP 2004-07 and TP 2004-08 were forwarded to the SNM Custodian on a daily basis when fragments were being handled, and these data sheets provided interim accountability for each fuel fragment.

When new fuel fragments were identified, the SNM Custodian would list and track the fragment on a living" Excel spreadsheet [the "Equivalent Fuel Fragment Length" (EFFL) spreadsheets.] This assured that the SNM Custodian had constant and current information about the number, locations and overall equivalent length of the fuel fragments.

Fuel fragment information from the TP 2004-07 and TP 2004-08 data sheets and the EFFL spreadsheet was incorporated into PG&E Calculation NX-288 (Reference 5) when the fragments were secured in their permanent storage container, or as otherwise appropriate.

PG&E Calculation NX-288 documents the total number of fuel fragments and tallies the length of fuel fragments found in the SFP and placed in permanent storage containers. 'Revision 6 of the calculation, dated April 21, 2005, lists a'total bof 175 fuel fragments. The' longest fuel fragments included in the 175 fragment inventory are a 52-inch, a 30-inch, a 16-inch; two 13-inch, and a 10-in'ch fragment. One hundred twenty eight (128) fragments identified had an effective fuel length of less than 1 inch.

The remaining fragmen ts ranged from I to 10 inches. The inventory of fragments listed in PG&E Calculation NX-288 is extensive enough to support the evaluation performed by ATI Consulting (Reference 14) that suggests that the end remnants of the A-49 fuel rod, and possibly one or more of the A-49 segments themselves,-are in the' SFP as fuel fragments.

The EFFL spreadsheet was maintained on the S: (shared drive) of the HBPP computer network.

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1i 1UL This calculation also verifies that the sum of the equivalent fuel lengths contained in the fuel fragments and in SNM waste (from Reference 7) is such that the criticality analysis of TBD-305 (Reference 20) remains valid.

Calculation NX-290, Revision 2 (Reference 6) determines the SNM contained in the fuel fragments to be a total of 5.7 kg of Uranium and 118 grams SNM.

Note that a "final" SFP search will not be possible until the fuel assemblies are transferred to ISFSI and other obstacles removed from the SFP -

events not scheduled to occur until at least several years from now.

However, the intensive SFP search conducted over the last few months is complete and HBPP believes - with a reasonably high level of confidence

- that the recovery of significant fuel fragments is complete. There are a limited number of areas in the SFP that were not fully accessible for search, including some areas beneath the fuel racks and energy absorber.

Should any fragments remain in these areas, they are expected to be minimal.

Fuel fragments have been retrieved, characterized and stored in special containers in the SFP (References 9 and 10). As a result, the SNM content in each storage container and the location of each storage container has been documented.

The SNM contained in known fuel fragments was calculated and the total amount (for 174 fragments) reported in the Project Interim Reports, dated February 22, 2005, PG&E Letter HBL-05-001. Since the issuance of the Interim Report, one additional fuel fragment has been found. The SNM contained in this additional fuel fragment will be included in the next annual DOE/NRC Form 7426.

3.2.3 A-49 In November 2003, work in the SFP was stopped while the implications of identifying fuel fragments within the SFP were reviewed. In early 2004, a reassessment of the SNM inventory began. In late June 2004 during document reviews as part of the reassessment, a discrepancy involving assembly A49 and the cutting of one of its rods was discovered. PG&E notified the Region IV office of the U. S. Nuclear Regulatory Commission (NRC) concerning the potential discrepancy on June 28, 2004, and immediately began the process of reconciliation of the records.

6 As of the date of this Final Report, Calculation NX-288 had been revised to include one approximately two inch fuel fragment found in March 2005. Calculation NX-288 data is an input to Calculation NX-290, so NX-290 would require revision to accurately reflect the total SNM in the fuel fragments. PG&E contacted the NRC to determine if a revised Material Status Report is required to document the discovery of the additional fuel fragment. The NRC stated that the Material Status Report need not be updated until the next scheduled submittal date. NX-290 will be revised to reflect the updated SNM totals for all fuel fragments prior to the next Material Status Report submittal.

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In September 1968, a portion of one fuel rod in a stainless steel-clad assembly (assembly ID #,A-49) was cut with the intent of sending three 18-inch segments offsite for study. The study was ultimately cancelled and the three segments remained onsite, with their last documented location - in 1968 - being the SFP, placed in a special pipe container.

Assembly A-49 was sent for reprocessing in 1969 but there are no records that the cut rod segments were sent with the assembly.

Document reviews and personnel interviews have determined that: (1) the A-49 fuel rod was cut into several pieces, including three approximately eighteen inch segments, (2) the fuel rod segments were not shipped offsite to Battelle Memorial Institute (Battelle) in Columbus, Ohio, as originally intended because the Battelle study that the segments were intended to support was cancelled and the rod segments were returned to the SFP, (3) the last record of the fuel rod segments was a Special Work Permit specifying that the segments were stored in the SFP, (4) Battelle records indicate that the shipment container originally intended for transport of the fuel rod segments was returned to Battelle empty, as expected, (5) the remnants from the A-49 rod were placed in the central storage container in the SFP, and (6) portions of the A-49 rod, including a fuel rod bottom end may be located in the SFP (Reference 14).

Procedures for handling fuel fragments were developed and physical work in the SFP resumed in July 2004. During the last half of 2004 into early 2005, a significant amount of work was completed in the SFP to search for the missing A-49 rod segments.

Possible searches for the A-49 fuel rod segments in the SFP are complete. Note that a "final" SFP search will not be possible until the fuel assemblies are transferred to the ISFSI and other obstacles such as the spent fuel racks are removed from the SFP - events not scheduled to occur until at least several years from now. However, the intensive SFP search conducted over the last few months is complete. HBPP believes -

with high confidence - that the three fuel segments are not in the SFP in their original form (i.e.,'as'intact 18-inch long segments). However, there is a reasonable possibility that some or all of the segments have been located in fragment form in the SFP.

An evaluation performed by ATI Consulting (Reference 14) suggests that the end remnants of the A-49,fuel rod, and possibly one or more of the A-49 segments themselves,- are in the SFP as fuel fragments. If this is the case, the A-49 segments are now accounted for as fuel fragments and stored in one of the fuel fragment containers described in Section 3.2.2 of this report.

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IIlI The accountability records are correct in that they track all known fragments and do not specifically include or exclude the A-49 fuel segments.

3.3 NON-FUEL SNM Discussion SNM has been utilized at HBPP in three applications outside of fuel; nuclear sources, fission chambers, and incore detector ion chambers. Calculation NX-287 (Reference 4) has a full listing of non-fuel SNM used at HBPP.

Definitions have been provided in the Section 2.3 of this report. The definition for Incore is reproduced here and a working description for Fission Chamber is also provided for convenience:

• Incore: An incore (also called an incore string) is an assembly of three ion chambers. The ion chamber (also called an incore detector) contains SNM; the rest of the incore is not SNM. An incore segment is a partial length of an incore string, which may or may not hold one or more ion chambers.

• Fission Chamber A fission chamber is a neutron detector utilized for core physics testing.

3.3.1 INCORE DETECTORS (ION CHAMBERS)

SNM utilized in incore instrumentation remained contained in its original enclosure and their location and movement was tracked by plant administrative procedures related to control of SNM. These tracking procedures were generally successful in accurately characterizing the site inventory and location of this SNM, except for, in some instances, incore instrumentation that reached the end of its service life and was placed in the SFP for storage.

Incore instrumentation SNM is contained in discrete ion chambers 2% to 3% inches long. Three ion chambers are located inside a 16-foot instrumentation tube (sometimes referred to as a 'string') at controlled positions in the reactor core. At end of service life, these long tubes were typically cut into smaller pieces for easier storage in the SFP; however, the location of the three ion chambers containing SNM (which of the cut pieces contained the chambers) was apparently not rigorously documented and controlled in all instances.

An extensive review of plant records (Reference 4) identifies a total of 24 devices containing ion chambers as remaining onsite at HBPP Unit 3.

Of these 24, there are 6 incore strings that are unirradiated and reside in special containers in the refueling building (RFB) outside of the SFP.

These 6 devices are periodically verified by the HBPP SNM inventory and accountability procedures (References 2 and 3).

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The Project document search effort identified a memorandum to file dated February 24, 1986, describing efforts to characterize the incore detectors in the 18 strings remaining in the HBPP SFP. At the startof the effort, 9 of the 18 strings were intact and the other 9 had been cut up in earlier years.

HBPP Temporary Procedure November 25, 1985,-No. 2, "Cutting In-Core Assemblies" provided both a measurement criterion and a dose-rate criterion as methods to identify the location of ion chambers in the incore strings. The process to'cut the nine uncut strings was based principally on the physical location/measurement criterion of the detectors in the string..

The February 24, 1986, memorandum includes vendor drawings indicating the position of the detectors' in the string. This cutting methodology resulted in segregation of the 27 detectors (three detectors per string, 9 strings) into individual segments of the original incore string. These individual sections measured approximately 10 to 15 inches in length.

The pieces of the nine incore strings cut up in earlier years were examined. Incore strings extend into the reactor and terminate at what is termed a 'hot end.' The hot ends for six of the nine strings were identified, nominal 1 0-inch sections containing a detector were cut from the six hot end pieces, and the remainder was discarded as radioactive waste.

These six 1 0-inch pieces were added to the twenty seven pieces generated from the cuffing of the intact strings identified above. This resulted in thirty three nominal 10-inch segments that were known (via physical measurement per vendor drawings) to contain detectors.

The remaining three hot end pieces were identified later in the 1985 cleanup campaign. Two of the three hot ends were approximately 30 inches in length. Vendor drawings indicate the detector closest to the hot end is approximately 22 inches from the hot end. Thus, the two 30-inch pieces 'each contained a detector. The last remaining hot end was approximately 18 inches in length and was presumed notto contain a detector.

At this point, a total of 35 detectors (27 detectors cut from the 9 uncut strings, 6 cut from the hot ends from strings cut up in earlier years, and 2 detectors known to reside in'the two 30-inch hot end pieces identified later in the cleanup campaign)'were accounted for via physical measurement.

Figure 3.3-1 below provides an additional illustration of the state of incore detector 'accountability at this point in HBPP operating history.

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FIGURE 3.3-1 FLOW CHART OF INCORE DETECTOR ACCOUNTABILITY AT CONCLUSION OF 1985 SFP CLEANUP CAMPAIGN Two processes were described in the February 24, 1986, memorandum to account for the remaining 19 detectors. The first process attempted to verify that the expected total length of 9 strings prior to being cut up correlated with the combined lengths of the pieces of the cut up strings.

The results indicated that the combined length of the cut up pieces was close to the lower estimate of the length of the incores prior to cutting, presumably accounting for all of the incores. The second process was a dose rate analysis of the 42 remaining pieces from strings cut up in earlier years. Of the 42 pieces, 19 had dose rates greater than 50 R/hr. The greater than 50 R/hr dose rate for the 19 pieces was the basis for detector accountability.

The 1985 procedure for determining the presence of ion chambers in incore sections proved inconclusive when used for low dose incore sections in 2005. As a result, these low dose incore sections were, by procedure, physically opened and visually examined to verify the presence or absence of ion chambers. Figure 3.3-2 below appends Figure 3.3-1 with 2005 results:

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FIGURE 3.3-2 FLOW CHART OF INCORE DETECTOR ACCOUNTABILITY AT CONCLUSION OF PROJECT SFP SEARCH CAMPAIGN OF 2005 TOTAL INCORE DETECTOR ONSITE INVENTORY 24 STRINGS WITH 3 DETECTORS PER STRING (72 DETECTORS)

KIRRADIATED STRINGS.

NINE IRRADIATED STRINGS SIX UNIRRADIATED STRINGS NINE IRAIAE TRNSCONTAINING 27 DETECTORS STORED IN TWO CONTAINERS CONTAINING 27 DETECTORS CUT CUT INTO PIECES DURING 1985 IN REFUELING BUILDING INTO PIECES PRIOR TO 1985 SFP CLEANUP CAMPAIGN INTACT STRINGS ACCOUNTABILITY ACCOMPLISHED BY SURVEILLANCE TEST PROCEDURE 3.6.6 6INNOMINL 10 INCH HFULL INVENTORY OF 27 6DETECTORS DETECTORSAILINDIVIDUA LEG ENCTFOM3D NCSO CUT SEGMENTS OF NOMINAL

--ENDS INCH LENGTH 5 OF THE 33 NOMINAL 10 INCH CUT SEGMENTS WERE VERIFIED AS CONTAINING A FISSION DETECTOR, SAMPLING VERIFIES THE REMAINING 28 CUT SEGMENTS EACH CONTAIN AN INCORE DETECTOR FOR A TOTAL OF 33 IDENTIFIED DETECTORS 2 DETECTORS IN 30 INCH HOT ENDS 19 DETECTORS UNACCOUNTED FOR -

IN 54 CUT INCORE PIECES ALL OTHER HOT ENDS AND INCORE PIECES EXAMINED. 17 FULL AND THREE PARTIAL DETECTORS IDENTIFIED Using these methods, on February 22, 2005, PG&E determined that there were only 50 complete an8'3'partial ion chambers stored in the SFP, indicating that 1 'complete dnd 3 partial ion chambers, thought to have been stored in the SFP for the'period 1985 through early 2005, were not properly controlled and accounted for.

Calculation NX-287:(Reference 4) examined the inventory of irradiated incore detector strings in' residen'ce at HBPP'and perfomned a statistical analysis to determine the upper bound, lower bound,- and best estimate for the SNM contained in the 3 partial and.1 full missing ion chambers. A range of values is given, reflecting the fact thatithe lengths of the ion chambers vary from 2 2'to 3% inches, which affects the amount of missing

'SNM.

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-It !l-The upper and lower SNM values for the missing ion chambers are derived by assuming all of the missing chambers are from strings with the highest and lowest SNM content. Note that the SNM content in transaction records is for the full string - its full complement of 3 detectors.

Values stated are for ion chamber detectors assumed to be 3% inches in length, parenthetical values are for ion chamber detectors assumed to be 2Y inches in length.

Upper Bound SNM Value = 0.124 (0.108) grams U-235 Lower Bound SNM Value = 0.0015 (0.00135) grams U-235 Best Estimate SNM Value is arrived at by taking a weighted average of SNM content for all strings residing in the SFP:

Best Estimate SNM Value = 0.038 (0.034) grams U-235.

A value of 0.035 grams U-235 for the SNM content of the missing 3 partial and one full ion chamber is a reasonable best estimate value given the uncertainty associated with nominal ion chamber length.

Note that DOE/NRC Nuclear Material Transaction Reports and the annual Material Status Summary Report do not require revision as the SNM contained in the missing 3 partial and one full ion chamber is less than 1 gram U-235.

Shipments of incore detectors to low level radioactive waste (LLRW) facilities were routinely made by boiling water reactor licensees. HBPP engaged in this practice (e.g., AEC Form 578), Material Status Report for period ending December 31, 1968, indicates that six expended incore flux detectors were discarded as radioactive waste during the report period. It is reasonable to assume that the one complete and three partial missing incore detectors were erroneously shipped offsite as irradiated hardware.

Prior to 1985, items such as incore detectors (also referred to as low power range monitors (LPRM)) that contained minimal amounts of SNM were required to be "stabilized" prior to disposal at an LLRW facility.

Stabilization consisted primarily of encapsulation that utilized a metal container filled with concrete or similar material to "hold" the SNM in the LPRMs. After 1985, the LLRW burial requirements were modified to allow items containing minimal amounts of SNM, such as LPRM detectors, to be buried without segmentation of the detectors from the LPRMs, and subsequent stabilization.

The shipment of LPRMs was permissible both prior and subsequent to the regulatory modification regarding stabilization made in 1985. The erroneous shipment of three partial and one complete incore detectors to a LLRW facility would not represent a condition outside the LLRW facility design basis.

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The Safety Assessment for Public Health and Safety regarding the A-49 Fuel Rod Segments (Reference 21) examines shipment of the three A-49 fuel segments to three LLRW facilities; Beatty, Barnwell, and Hanford.

The Safety Assessment examined the materials included in the shipment and their origin. For Beatty, the only shipment of materials from the SFP was the shipment of incore flux detectors described above. No other Beatty shipment materials originated from the SFP, and the Safety Assessment dismissed Beatty as a viable repository for the A-49 fuel segments. Similarly, the one full and three partial incore detectors do not reside at Beatty.

Thus, the Project believes that the missing incore detectors are at either the Hanford or Barnwell facility.

The Safety Assessment includes an evaluation of the total SNM inventory at the two sites. The Hanford site had the lowest inventory of U-235, 101,915 grams. Clearly the added 0.035 grams from the' one whole and three partial incore detectors has a negligible effect on the LLRW waste site inventory.

The insignificant addition to the LLRW site inventory does not pose any increased risk to the health-and safety of the public or the environment not already anticipated for the long-term management of the LLRW facilities.

The Project team also evaluated the possibility of theft or diversion of the missing incore ion chambers. Using the same reasoning and approach as described in Section 4.5 for theft or diversion of the three missing fuel rod segments, the Project team has concluded that the theft or diversion of the missing ion chambers is highly unlikely.

The barriers that applied to theft or diversion of the fuel rod segments would also apply to deter, prevent, and detect an attempted theft or diversion of the missing ion chambers. The missing ion chambers have even less economic and strategic value' than the fuel rod segments and the radiation levels of the ion chambers through the 1980s were sufficient to present a-significant health hazard to a thief or an individual attempting to carry out diversion of the ion chambers for disposal without authorization.

3.3.2 FISSION CHAMBERS A review of pertinent documents associated with SNM content of fission chambers in Reference 4 found that all irradiated fission chambers have been shipped offsite. The total site inventory of fission chambers is two unirradiated chambers located in a storage container in the RFB. These chambers are physically verified as part of plant test procedures (Reference 3). Nuclear Material Transaction Report and Material Balance 3-27

__U-Report documents properly account for the SNM in the fission chambers used onsite and subsequently shipped offsite as well as the two unirradiated chambers remaining onsite.

3.3.3 PU/BE NEUTRON SOURCES PG&E Calculation NX-287 (Reference 4) found that HBPP Unit 3 possessed a 1-curie and a 5-curie plutonium/beryllium sourqe and that both sources have been subsequently shipped offsite. No sources containing SNM remain at HBPP. Nuclear Material Transaction Report and Material Balance Report documents properly account for the SNM in these sources. SFP cleanup efforts and other search activities by the Project have not identified any sources that contain SNM residing at HBPP.

3.4 SNM WASTE 3.4.1 SNM SHIPPED OFFSITE AS PART OF RADIOACTIVE WASTE SHIPMENTS Offsite shipments that include SNM are required to have companion Material Transaction Reports (DOE/NRC Form 741) that characterize the SNM in the shipment.

Document review of historical Material Transaction Reports and Material Status Reports (DOE/NRC Form 742) found that shipments that had SNM quantities of I gram or greater had appropriate transaction forms and updates to the Material Status Report were made.

The large majority of shipments did not contain SNM in quantities approaching I gram, and thus did not require transaction forms.

Currently, a portion of the HBPP radioactive waste shipments have been reviewed and the SNM values totaled. This total does not include all radioactive waste shipments. However, the total includes a large majority of the waste shipments associated with the 1976 and 1983 pool cleanup efforts.

PG&E will complete its review of these shipments and provide updated Material Transaction Forms as needed, and include any SNM identified in these shipments in the next Material Status Summary report.

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3.4.2 SNM OUTSIDE OF ITS ORIGINAL APPLICATION AND INCAPABLE OF PRECISE CHARACTERIZATION Discussion In the previous sections of this report, SNM located in fuel assemblies, fuel fragments, fuel segments; sources, fission chambers, incore detector ion chambers, and SNM shipped offsite in waste shipments'were examined. These SNM groupings were capable of being precisely characterized, as the SNM w'as in its original configuration, br has been quantified via PG&E calculation's, or has been determined via analysis as required by waste shipment procedures.

As discussed earlier'in this report, SNM (some of it in the form of fragments) was released from da'maged assemblies into the reactor coolant system (RCS) or the SFP primarily from the Type I, stainless steel-clad fuel. All of the stainless steel-clad fuel assemblies (189) have been shipped offsite and have been reprocessed, rendering a physical inventory of the stainless steel 'fuel cladding failures impossible. None of the clad fuel fragments were zircaloy'(Reference 10).

HBPP has characterized the SNM components of the various locations in which SNM in the form of fuel fragments from failed Type I, stainless steel-clad fuel resides. PG&E Calculation NX-288 (Reference 5) determines the quantity of, and total 'equivalent length of fuel in, the fuel fragments identified and collected in'storage containers in the SFP. The SNM content of the fuel fragments is determined in PG&E Calculation NX-290 (Reference 6).

HBPP embarked on several cleanup campaigns in various plant locations,

' principally the reactor vessel and SFP. Significant cleanup projects were completed in 1976, 1983, and 1986. In some cases the SNM collected during these cleanup efforts was appropriately shipped offsite as radioactive waste in quantities 'documented on DOE/NRC transaction forms. In other cases, SNM collected remains onsite in demineralizer resin media, filtration system filters, vacuum system 'bags,' and specialized'containers in the SFP.

This section examines othe'r locations for SNM where conditions are such that a precise estimate of the SNM is not possible. However, the basis for reasonable estimates is provided in the following discussions.

Calculation Constraints SFP cleanup campaigins included removal of sediment/debris that accumulated on the flo6or'f the SFP. Some areas of the SFP floor are inaccessible and will remain'so until the fuel is off-loaded to the ISFSI facility (scheduled to occur several years from now). The thickness of the 3-29

ul-sediment/debris layer is not easily measured and requires assumptions as to its thickness. The SFP floor area is large when compared to the sediment/debris layer thickness - small changes in thickness have a profound affect on the total material volume.

As described above, the SNM contained in the sediment/debris is intermingled with several other components, and it is reasonable to assume that the contribution of SNM to sediment/debris would vary in different plant systems or locations. Thus, assumptions related to sediment/debris layers on the SFP floor render a precise determination of the SNM in the SFP extremely difficult.

Early cleanup efforts included vacuuming the reactor vessel. The vacuuming covered areas above the lower core plate. Some areas below the core plate were partially accessed by winding the vacuuming device suction line through the lower core plate flow holes. These cleanup efforts were effective in collecting sediment/debris from areas above the lower core plate. A complete vacuuming of the lower reactor plenum area (below the lower core plate) was incomplete due to obstructions. Thus, an indeterminate, but limited, number of fuel fragments as well as a sediment/debris layer containing SNM are expected to be located in the reactor vessel.

The design dimension difference between the inside diameter of the Type 1, stainless steel fuel cladding and the diameter of the fuel pellets is a range of 0.002 to 0.007 inches. During operation, the pellet swells slightly, and there is a tendency for the surface of the pellet to contact the inside of the cladding. This makes it less likely (but not necessarily impossible) that pellets could escape from the inside of any pieces of broken cladding.

Exposed pellets could be subject to some erosion (thereby dispersing very fine fuel particles into the coolant), or if they were in the lower quarter of the assembly (below the rod locating grid), they might fall through the assembly nosepiece and into the reactor or the SFP.

The reactor vessel has remained closed and the plant has remained in SAFSTOR status for the duration of the Project. Physical verification of the sediment/debris layer and the potential presence of any fuel fragments in the vessel lower plenum were not and could not be verified.

Stellite/Cobalt 60 Some SNM waste sediment/debris recovered from storage containers in the SFP is intermingled with stellite used as reactor control rod guides.

The presence of the highly activated cobalt-60 in the stellite adds complications to radiological characterization of the sediment/debris by dose rate methods. Additional assumptions over and above those made 3-30

for the sediment/debris in the reactor vessel and the SFP floor are required, adding additional uncertainties to the SNM quantification efforts.

Non-SNM Impurities Released to Plant Systems Several other sources of gross contamination that were released to the reactor and SFP water add uncertainties to the composition of the sediment/debris layer that was deposited in the reactor, RCS and SFP.

Most of the Type I, stainless steel fuel clad assemblies were placed in a ufuel washer" in the SFP for cleaning prior to inspection and reuse.

Oxides, fuel fragments and SNM waste from this operation were collected in a pellet catcher and generally transferred into the SFP central storage container.

Therefore, limitations in determining how much SNM was released due to the Type I, stainless steel fuel clad failures, and an unknown contribution from spalling, oxides, and Iother non-SNM materials are intermingled with the SNM in the sediment/deb'ris dispersed in plant systems. These limitations act to make a precise quantification of SNM contained in this

-sedirent/debris extremely difficult..

PG&E Calculation NX-291-(Reference 7) determines the SNM content of SNM waste contained in loose sediment found in various locations, describes the assunptions' made in the estimate, and lists the individual isotopic constituents of the SNM waste. The following plant locations where SNM is known to reside-are'evaluated by PG&E Calculation NX-291:

• SFP, including the SFP floor and resins that accumulated on the SFP floor.

• SFP Interim Storage Container 18 (ISC-18).

• SFP demineralizer and Resin Disposal Tank.

Vacuum demineralizer.

• Tri Nuclearfilters.

As the plant decommissioning process continues, estimates of SNM residing in the above plant locations will be revised if and as necessary to reflect as-found data.

3.4.3 SNM WASTE DISTRIBUTED ON SFP SURFACES As part of the Project, extensive; cleanup and inspection work was performed in the HBPP'SFP. This work involved estimating the SNM content of the various mraterials colle cted from the SFP.

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Lao In some cases, physical limitations (presence of fuel racks, energy absorber device, etc.) rendered collection of these materials from some locations of the SFP impossible. These areas have enough physical access that a remote visual inspection was possible.

An estimate of this SNM inventory may be made by recognizing: (1) the composition of the material removed from other, fully accessible areas of the SFP may reasonably be used as an assumed composition of the materials in inaccessible areas; (2) no fuel fragments (comprised of fuel pieces greater than 1/4 inch in diameter) or segments were recovered from the accessible areas of the SFP - all large fragments were in the central storage container or other specialized storage containers; and (3) the estimate that approximately 20 percent of the total SFP surface area is not fully accessible and has not had its deposition material collected.

Assumptions as to the thickness of the sediment/debris layer and its constituents were used to arrive at totals for SNM contained in the sediment/debris layer for the SFP.

The evaluation of the resin pile that was located along the north wall of the SFP rested on the assumption that 5 percent of the resin pile, by volume, was comprised of SNM in quantities that are identical to that of the sediment. Section 6.4 of PG&E Calculation NX-291 (Reference 7) provides an isotopic quantification for the sediment deposited in the SFP.

The verifiable data consisted of: (1) a sample result of sediment taken in 1985, and (2) the physical layout of the SFP. The remainder of the calculation relied on the assumptions described above.

PG&E Calculation NX-291, determined a total of 24 grams of Uranium and 0.39 grams SNM as residing on the SFP floor, in both accessible and inaccessible areas.

Updated DOE/NRC Forms 741/742 submitted on March 17, 2005, PG&E Letter HBL-05-007, reported the inventory of SNM at HBPP in the form of fuel fragments or SNM waste from Type I, stainless steel-clad fuel failures.

The SNM contained in the sediment/debris on the floor of the SFP is a subset of that quantity of SNM; therefore, the SNM in this material is properly reported as resident at HBPP.

3.4.4 SNM WASTE IN INTERIM STORAGE CONTAINER 18 (ISC-18)

During the last half of 2004 and January of 2005, various storage containers within the SFP were examined and the contents of each evaluated (References 9 and 10). A sifting device was manufactured to support the sorting and evaluation of these materials. The device has a 1/4-inch screen that retains fuel fragments and irradiated hardware of appreciable size. Fuel fragments were sorted and removed from the 3-32

accumulated materials and stored in fuel fragment containers. Irradiated

'hardware from these materials 'was removed for packaging and storage, separate from SNM containing 'materials.

A combination of SNM waste and small pieces of other debris from the sifted material passed through the screen and are' currently stored in Interim Storage Container 18 (ISC-1 8) on the floor of the SFP.

The locations that this material was retrieved from are different from the sediment analyzed in the previous section. This difference in origin necessitated a different methodology for sample characterization. In addition, the material is known to have a constituent part that is stellite, as one of the components historically placed in the central storage container was stellite used in control rod guides.

ISC-18 has 4 inches of material in a 19-inch cylindrical containerwith a 1-inch thick by 17-inch diameter stainless steel disk acting as a ballast weight. The volume of this material is approximately 0.55 cubic feet.

This material contains SNM waste, small pieces of irradiated material not containing SNM, and debris composed of iron oxide, stellite, and other contaminants not containing SNM.

Section 6.6 of PG&E Calculation NX-291 (Reference 7) relies on a 2005 underwater survey of the ISC-18'contents and engineering judgment to arrive at total SNM waste value for the ISC-18 contents.

Calculation NX-291 determined a total of 322 grams of Uranium and 4.24 grams-SNM as residing in [SC-18.

Updated DOE/NRC Forms 741/742 submitted on March 17, 2005, PG&E Letter HBL-05-007, reported the inventory of SNM at HBPP in the form of fuel fragments or SNM waste from Type I, stainless steel-clad fuel failures.

The SNM contained in the sediment/debris in ISC-18 is a subset of that quantity of SNM; therefore, the' SNM in this material is properiy reported as resident at HBPP.

3.4.5 SNM WASTE IN SFP DEMINERALIZER AND RESIN DISPOSAL TANK The SFP demineralizer and disposal tank are the plant equipment utilized for maintenance of SFP water'chemistry. This equipment is not adjunct equipment utilized for special cleanup operations - the equipment is the

'base,' or installed'plant equipment.

PG&E Calculation NX-291 (Reference 7) identifies 570 cubic feet of resin

- comprised of 542 cubic'feet in the resin disposal tank and 28 cubic feet in the SFP demineralizer.

3-33

Il:L The resin disposal tank and the demineralizer contain ion exchange resin.

Samples taken in 1997 and 2000 were utilized in characterization of the SNM in the resin media. The results from these two samples were decay corrected and averaged. The average was compared to values determined for sediment/debris deposition layers in the SFP. The comparison used Plutonium isotopes and determined that the ratio of the demineralizer samples and the sediment/debris sample taken in 1985 ranged from 0.85 percent to 1.36 percent.

This ratio of approximately 1 percent was applied on a volumetric basis to the resin to arrive at a SNM characterization for the resin.

PG&E Calculation NX-291 determined a total of 125 grams of Uranium and 2.03 grams SNM as residing in the SFP demineralizers and resin disposal tank.

Updated DOE/NRC Forms 741/742 submitted on March 17, 2005, PG&E Letter HBL-05-007, reported the inventory of SNM at HBPP in the form of fuel fragments or SNM waste from Type I, stainless steel-clad fuel failures.

The SNM contained in the sediment/debris in the SFP demin and resin disposal tank is a subset of that quantity of SNM; therefore, the SNM in this material is properly reported as resident at HBPP.

3.4.6 SNM WASTE IN DIVERSIFIED TECHNOLOGIES SERVICES (DTS)

VACUUM DEMINERALIZER The DTS vacuum system was used for the recovery of sediment/debris from the bottom of the SFP and recovery of the resin pile located near the north wall of the SFP. The vacuum system demineralizer captured the sediment/debris and resin.

The composition and amount of the sediment/debris layer on the SFP floor and the resin pile near the north wall was described in Section 3.4.3. The vacuum demineralizer geometry was used to determine a thickness for the resin, and sediment/debris that was collected by the DTS system and for the charcoal layer.

These exercises showed that the DTS system demineralizer had a layer of charcoal (about 5 cubic feet), under a layer of resin (about 15 cubic feet),

under a layer of sediment/debris (about 3 cubic feet).

After the thickness and orientation of the resin, sediment/debris, and charcoal layers were determined, expected dose rates were modeled utilizing a computer-modeling program. The results of this model were compared to a survey of the demineralizer vessel performed on January 25, 2005. The model dose rate value was slightly less than the survey results.

3-34

This difference was attributed to particulate SNM waste distributed non-homogeneously in the three layers of the demineralizer vessel (resin, sediment/debris, and system charcoal). The calculation assumed an additional amount of particulate SNM waste corresponding to the dose rate difference to arrive at the final SNM values.

PG&E Calculation NX-291 (Reference 7) determined a total of 530 grams of Uranium and 8.39 grams SNM as residing in the DTS derineralizer.

Updated DOE/NRC Forms 741/742 submitted on March 17, 2005, PG&E Letter HBL-05-007, reported the inventory of SNM at HBPP in the form of fuel fragments or SNM waste from Type I, stainless steel-clad fuel failures.

The SNM contained in the sediment/debris in the DTS vacuum demineralizer is a subset of that quantity of SNM; therefore, the SNM in this material is properly reported as resident at HBPP.

3.4.7 SNM WASTE IN TRI NUCLEAR FILTERS The Tn Nuclear filtration systermi is a recently installed unit that provides additional SFP water filtration to assist in maintenance of SFP water clarity and to provide additional filtration capacity to accommodate SFP cleanup activities such as vacuuming.

The system was installed during the latest SFP cleanup campaign (2004 to present). The system has functioned solely to provide filtration of SFP water. The system has not been used on other plant systems.

As of January 26, 2005,:10 filters have been used and surveyed. Two other filters remain in service. Survey results indicate that the dose' rate measured at the center of the axis of the filter ranges from 89 to 232 mR/hr, with an average dose rate of 150 mR/hr.

The filter vessel geometry was modeled and assumed each filter had 200 grams of SNM in the form of sediment/debris characterized in Section 6.2 of NX-291. This initial estimate resulted in a model dose rate of 140 mR/hr. The assumed sediment/debris in the filter was increased to arrive at a model dose rate of 150 mR/hr, matching the average of in situ survey results.

For the twelve filters, an estimated 2,600 grams of sediment/debris corresponds to the average dose rate values.

PG&E Calculation NX-291 (Reference 7) determined a total of 1.82 grams of Uranium and 0.03 grams SNM as residing in the 12 Tri Nuclear filters.

Updated DOE/NRC Forms 741/742 submitted on March 17, 2005, PG&E Letter HBL-05-007, reported the inventory of SNM at HBPP in the form of fuel fragments or SNM waste from Type I, stainless steel-clad fuel failures.

3-35

liL11 The SNM contained in the sediment/debris in the Tri Nuclear filters is a subset of that quantity of SNM; therefore, the SNM in this material is properly reported as resident at HBPP.

3.5 RECORDS Accountability Record Sheets Accountability Record Sheets document the physical location of SNM-containing items resident at HBPP. Accountability Record Sheets are updated by the SNM Custodian after each move of SNM-containing items is complete (or upon completion of alternate plant procedures that provide for interim accountability of SNM-containing items during specific activities involving these items). HBPP is not equipped with the facilities necessary to measure the precise quantity of each isotope of SNM contained in a given item. Consequently, shipping documents, physical inspection and characterization and/or isotopic composition calculations based on reactor operations are used to determine the isotopic quantities. Once SNM content is established for a discrete SNM-containing item, physical inventory and tracking of the item constitutes accountability for the item.

All SNM which has been identified by this Project, is currently documented and controlled as specified by approved HBPP procedures.

SFP Maps Maps of the SFP documenting the physical location of SNM-containing items resident in the HBPP SFP are maintained by the SNM Custodian. These maps are updated to show the locations of any SNM-containing items that remain stored in one location for more than 30 days.

Database I Calculation PG&E Calculation NX-290, SNM Database and Calculation (Reference 6),

documents the SNM inventory at HBPP - including fuel assemblies, fuel fragments, ion chambers (from incores), and SNM waste. The calculation also determines adjustments in the quantity of Pu241 due to decay (Pu241 is the only SNM isotope that decays to a degree that it could affect reporting.) The output of this calculation provides the input data for preparation of DOE/NRC Forms 7411742.

PG&E Calculation NX-290 is an expansion and enhancement to the data and calculations previously used to determine SNM inventory. The enhancements provided by PG&E Calculation NX-290 include:

SNM contained in fuel fragments and SNM waste is now addressed; previous calculations excluded the SNM contained in these materials.

3-36

The start date for calculating decay of Pu241 in each assembly is now based on the actual cycle shutdown date for that assembly; previous calculations calculated decay for all assemblies starting from July 19, 1976.

• The value used for half-life for Pu241 was revised to match the revised half-life value given in NUREG/BR-007, October 1 2003.

• The conversion factor used for days/year was revised to match the conversion factor given in the NRC Nuclear Materials Management and Safeguards System (NMMSS) newsletter, NMMSS News, May 2003.

3.6 PROCEDURES Accountability (HBAP D-7)

Administrative Procedure HBAP D-7, Control and Accountability of Special Nuclear Material and Waste Shipment, (Reference 2) specifies the accountability and control 'measuresfor SNM at HBPP.

HBAP D-7: (1) defines forms of SNM residing at the plant, (2) delineates the process used to control and document movement of SNM, (3) delineates the process by which SNM Accountability Records and SFP maps are revised to document quantity and location of SNM, and (4) identifies reporting requirements for:SNM accountability.

HBAP D-7 was revised in December 2004 (Revision 9) to enhance and clarify administrative requirements for SNM accountability. In particular, additional guidance was provided regarding accounting for fuel segments or fuel fragments to assure that these items are fully addressed by the SNM accountability program at HBPP. The procedure was revised again in January 2005 (Revision

10) making minor changes to improve the interface between HBAP D-7 and a concomitant revision to Surveillance Test Procedure STP 3.6.6, SNM Inventory.

Physical Inventory (STP 3.6.6)

Surveillance Test Procedure (STP) 3.6.6, SNM Inventory, (Reference 3) describes and directs the SNM physical inventory. STP 3.6.6 provides instructions for: (1) performing the periodic physical inventory of SNM at HBPP, (2) documenting the inventory, and (3) documenting any discrepancies, if they should occur.

STP 3.6.6 was revised in January 2005 (Revision 19) to enhance and clarify instructions for the physical inventory. In particular, some instructions for the physical inventory that were previously located in HBAP D-7 were relocated and consolidated in STP 3.6.6.

3-37

-. al9-3.7

SUMMARY

AND RESULTS The Project has reviewed documentation and performed additional physical inspections to reverify the current inventory of SNM at HBPP. Table 3.7-1 provides a summary of the current status and SNM content for Type I, stainless steel-clad fuel fragments and SNM waste addressed in this report.

Summary Result Review Referencing Table 3.7-1:

The total for SNM that may be precisely characterized (from fuel fragments -

Section 3.2.2) is 118 grams of SNM.

The totals for SNM that cannot be precisely characterized (from floor of SFP, ISC-18, SFP demineralizer, Resin disposal tank, SFP Vacuum demineralizer, and in TO Nuclear filters - Sections 3.4.3 through 3.4.7) sums to 15 grams of SNM.

The overall total of SNM from Type I, stainless steel-clad fuel failures (in the form of fuel fragments and SNM waste) as addressed in this report is 133 grams.

3-38

7 F

F TABLE 3.7-1

SUMMARY

OF ACCOUNTING FOR TYPE I / STAINLESS STEEL CLAD FUEL "STRANDED" AT HBPP C.)

an 0) 0.

M, C',

0.

80

-J

_j

'a a)

C.

a) a)

C.)

co0 z

U, Ca)

-a Cn

.' E

.C 00 E

I-0) z I-Distribution That Can Be Precisely Characterized:

Fuel Fragments 3.2.2 All identified (282.7 equivalent inches In SFP, stored in specially designed fuel 5, 6 118 118 of) fuel fragments have been fragment containers.

- retrieved, characterized and stored.

Distribution That Cannot Be Precisely Characterized - SNM Waste:

On Floor of SFP 3.4.3 Accumulated waste was vacuumed Material removed from the SFP floor 7

0.4 from SFP floor in Jan 2005 to extent during vacuuming now resides in SFP possible; a small amount of material vacuum demineralizer and Tri-Nuclear has settled on floor and remains in

-'filters (see below). A lesser volume of inaccessible areas.

material remains'distributed on the SFP

-floor.

In Interim Storage 3.4.4 Contains -1 2 cubic foot of Located on the SFP floor.

7 4.2 Container 18 (ISC-18) accumulated waste from various SFP storage containers that passed through % inch sifting device.

15 In SFP Demineralizer /

3.4.5 Installed plant equipment contains SNM containing resins are held in the 7

2.0 Resin Disposal Tank

-570 cubic feet of resins' with SFP demineralizer and the Resin quantities of SNM.

Disposal Tank.

In bTS Vacuum 3.4.6 Contains -23 cubic feet of resin, SNM containing materials are held in the 7

8.4 Demineralizer sediment/debris and charcoal from DTS vacuum demineralizer vessel, the Jan 2005 SFP vacuuming.

located in the SFP.

In Tri-Nuclear Filters 3.4.7 There are 10 used filters and 2 All filters are in the SFP.

7 Trace additional filters still in service.

TOTAL 133 3-39

hR-m.

3.8 REFERENCES

1.

Procedure TP 2004-09, "Special Nuclear Material (SNM) Inventory, Inspection & Control Project - Phase 2."

2.

Procedure HBAP D-7, "Control and Accountability of Special Nuclear Material and Waste Shipment."

3.

Procedure STP 3.6.6, "SNM Inventory."

4.

Calculation NX-287, 'Verification of HBPP Special Nuclear Materials Inventory."

5.

Calculation NX-288, "Documentation of Spent Fuel Fragments."

6.

Calculation NX-290, USNM Database and Calculation."

7.

Calculation NX-291, "Estimation of SNM Waste at HBPP."

8.

Procedure TP 2004-05, "Transfer Fuel Assembly UD-6N to a New Storage Container."

9.

Procedure TP 2004-07, "Movement of Fuel Fragments and Non-Fuel Material in Spent Fuel Pool."

10. Procedure TP 2004-08, "Fuel Fragment Evaluation and Container Loading."

11. Procedure TP 2004-10, "Incore Detector Evaluation and Container Loading."

12. Procedure TP 2004-12, "Vacuuming of Resins and also General Area Vacuuming in the Spent Fuel Pool Floor Area."

13. SNM Project Report, "Engineering Review of Control and Accountability of Modified Fuel Assemblies at Humboldt Bay Power Plant," dated January 28, 2005.

14. ATI Consulting Report, "Evaluation of Fuel Rod Fragments and Inference to Fuel Rod A-49 at Humboldt Bay Nuclear Power Plant," dated March 31, 2005.

15. PG&E Letter to US DOE dated October 27, 1986, chron #087740.

16. Memorandum, "Special Nuclear Material Fuel Assembly Accountability for Humboldt Bay Unit 3," dated March 12,1993, chron #204703.

17. SNM Project Report, "Fuel Assembly UD-6N".

18. PG&E Letter No. HBL-04-027, "Annual Material Status Reports for the Period Ending September 30, 2004," sent to the NRC and NMMSS.

19. Memorandum to File dated February 24, 1986, describing the processing of incore strings and description of the quantity of cut up fission strings in the SFP containers.

20. Technical Basis Document TBD-305, "Spent Fuel Pool Fragment and SNM Evaluation."

3-40

21. SNM Project Safety Analysis Report, "Public Health & Safety HBPP Unit 3 A-49 Fuel Rod Segments."

22. DCN HB3-EM-549, "Storage Containers for Fuel Fragments."

23. AEC/NRC Inspection Reports for Surveys/Audits of SNM at HBPP, dated February 10,1965, August 19, 1969, December 5, 1972, and September 12,1975.

24. AEC Inspection Reports Related to Fuel Failures at HBPP, dated December 13, 1965, and August 23, 1966.

25. ANSI Standard 15.8-1974, Nuclear Material Control Systems for Nuclear Power Plants," October 22, 1974.

26. Regulatory Guide 5.29, 'Nuclear Material Control Systems for Nuclear Power Plants," Revision 1, June 1975.

3-41

4.0 SCENARIOS FOR MISSING FUEL ROD SEGMENTS This section contains an analysis of~the five plausible scenarios for possible disposition of the three missing fuel 'rod segments. The scenarios assess the likelihood of the fuel rod segments being at specific end locations and the credible means by which they could reach these locations. Also described in this section are the evaluation criteria used to determine that it was implausible for the fuel rod segments to be contained in certain shipments of radioactive waste and materials and, finally, a discussion of the possibility of the fuel rod segments being located in the spent fuel pool (SFP) in an altered configuration.

A written disposition of each scenario was prepared that included a description of the scenario, investigation, analysis, conclusions, and recommendations. The conclusions for each scenario assigned one the following four possibility categories:

• "Highly Unlikely" means the event is very improbable.

• 'Possible, But Not Likely" means the event, while possible, would have a fairly low probability of occurrence.

• "Reasonably Possible" means the event may have occurred.

' Confirmed" means the event did occur.'

4.1 SPENT FUEL POOL PHYSICAL'INSPECTION After the formal initiation of the Special Nuclear Material (SNM) Project,'the team followed Humboldt Bay Power Plant (HBPP's) early physical inspections with searches that were estimated to have a high-likelihood of success in finding the three fuel rod segments or the canister.

During the course of this'initial inspection,'the Project team began developing a detailed and comprehensive' pla'fintended to identify and inspect all likely and accessible areas in the HBPP SFP where the three fuel rod segments, the special pipe container, and/or broken or cut rod segments and/or remnants of the segments could be stored. With the assistance of HBPP operations, engineering, and maintenance personnel, the Project established a comprehensive list of locations capable of accommodating the three fuel rod segments in a number of various configurations. This list was known as the Global Inspection Plan (Inspection Plan).

The Inspection Plan for the SFP considered whether any or all of the three unaccounted for 18-inch fuel rod segments associated with fuel assembly A-49 remain stored in the Unit 3 SFP in an undocumented location or item. The various SFP locations and items considered the A-49 rod segments to be in one (or more) of three possible physical configurations: (A) intact approximately 18-inch long fuel rod segments, (B) damaged (broken, crushed, or cut) fuel rod 4-1

uL.

segments (i.e., fragments), or (C) fuel rod segments in the special pipe container.

In addition to the specific search for the A-49 fuel rod segments, the search also included physical configuration D, the identification of other potential fuel (in the form of fuel fragments not specifically identified as being from A-49) and non-fuel SNM found during the physical inspection.

The Inspection Plan established a comprehensive list of discrete locations and items in the SFP that were capable of physically accommodating the three A-49 fuel rod segments or the special pipe container in which the segments were last seen. The Plan recognized earlier inspections conducted prior to the formation and implementation of the Project, and the fuel assembly inspection activities of 2000 associated with pre-independent Spent Fuel Storage Installation (ISFSI) activities. The Plan was implemented in a thorough manner. In general, the inspection locations were accessible, ensuring complete and conclusive results based on visual inspection or radiation dose assessment. In some cases, a portion of the item or location being inspected was accessible, but was partially obscured or equipment was not available to fully assess the location or item. In those cases, further discussion and justification was provided. For those items and locations that could not be dispositioned, action items were identified. The planned objectives for each inspection were satisfied.

The Inspection Plan identified the specific locations inspected and items examined, unique characteristics associated with the location or item, identified previous activities associated with the location or item, and the planned inspection and examination methods and techniques that would be utilized. As with the non-pool scenarios, when additional information or insights suggested other locations or new examination techniques not previously considered, the Project would amend the Inspection Plan to incorporate those additional locations and techniques. Table 4.1-1, "Spent Fuel Pool (SFP) Global Inspection Plan (Physical Inspection) Scenario Descriptions" below lists the fifty-six scenarios addressed by inspection or other confirmatory action. The scenario areas can be located on Figure 1, HBPP Unit 3 Spent Fuel Pool Schematic Configuration for Physical Inspections.

4-2

TABLE 4.1-1 SPENT FUEL POOL (SFP)

GLOBAL INSPECTION PLAN (PHYSICAL INSPECTION)

SCENARIO DESCRIPTIONS Area/

SNMP Area or Item to be Description & Location of Item No. Sario Examined Area/Ifem SAP8065936 I

1-04-01a Fuel Rack Area 389 Fuel Assemblies located in the Fuel Assemblies (389 assemblies, Peripheral Cells and the Storage Rack does not Include UD-6N)

Cells as depicted on Figure 1, SFP Schematic Diagram.

2 1-04-01b Fuel Rack Area 45 Peripheral Cells noted as locations 1 Peripheral Cells (45 cells)

- 45, Inclusive and as depicted on Figure 1, SFP Schematic Diagram.

3 1-04-O1c Fuel Rack Area 45 Peripheral Cells Upper Rack Structure Peripheral Cells (45 cells) Upper noted as locations 1 - 45, inclusive and Rack Structure as depicted on Figure 1, SFP Schematic Diagram.

4 1-04-01 d Fuel Rack Area 45 Peripheral Cells Middle-Tier Rack Peripheral Cells (45 cells) Middle-Structure noted as locations 1 - 45, Tier Rack Structure inclusive and as depicted on Figure 1, SFP Schematic Diagram.

5 1-04-Ole Fuel Rack Area 45 Peripheral Cells Lower Rack Structure Peripheral Cells (45 cells) Lower noted as locations 1 - 45, Inclusive and Rack Structure' as depicted on Figure 1, SFP Schematic

-Diagram.

6 1-04-01f Fuel Rack Area Areas of the Peripheral Cells Between Peripheral Cells (45 cells) Between Cells and SFP Walls (North, East &

Cells and SFP Walls (North, East West) noted as locations 1 - 45,

& West) inclusive'and as depicted on Figuredl,

._ ;_ -SFP Schematic Diagram.

7 1-04-19 Fuel Rack Area 352 Storage Rack Cells bounded by the Storage Rack Cells (352 cells) grid coordinates 50-01, 50-16, 71-16 and 71-01, inclusive and as depicted on Figure 1, SFP'Schematic Diagram.

8 1-04-alb Fuel Rack Area 352 Storage Rack Cells Upper Rack Storage Rack Cells (352 cells)

Structure bounded by the grid..

Upper Rack Structure coordinates 50-01, 50-16, 71-16 and 71-01, inclusive and as depicted on Figure 1, SFP Schematic Diagram.

9 1-04-O1i Fuel Rack Area 352 Storage Rack Cells Middle-Tier Rack

-Storage Rack Cells (352 cells)

Structure bounded by the grid Middle-Tier Rack Structure coordinates 50-01, '50-16, 71-16 and 71-01; inclusive and as depicted on Figure SFP Schematic Diagram.

10 1-04-11 Fuel Rack Area 352 Storage Rack Cells Lower Rack Storage Rack Cells (352 cells)

Structure bounded by the grid Lower Rack Structure coordinates 50-01, 50-16, 71-16 and 71-01, inclusive and as depicted on Figure 1, SFP Schematic Diagram.

4-3

I, ilL TABLE 4.1-1 SPENT FUEL POOL (SFP)

GLOBAL INSPECTION PLAN (PHYSICAL INSPECTION)

SCENARIO DESCRIPTIONS Area/

SNMP Area or Item to be Description & Location of Item No. Scenario No.Examined Arealtlem 11 1-04-01k Fuel Rack Area Areas between the Storage Rack Cells Storage Rack Structure Between (bounded by the grid coordinates 50-01, Storage Rack Cells and Peripheral 50-16, 71-16 and 71-01, inclusive) and Cells the Peripheral Cells (noted as locations 1

- 45, inclusive) as depicted on Figure 1, SFP Schematic Diagram.

12 1-04-01i Fuel Rack Area The gap space between the outside Gap - Boral Can & Cell (389 cells) surface of the fuel assembly Boral can and the inside surface of the fuel rack cell in order to determine if the gap is wide enough to accommodate a fuel rod I_

segment or fragment.

13 1-04-01m Fuel Rack Area The two (2) vertical pipes located Vertical Pipes (Part of the Storage between the Storage Rack Cells between Rack Cells) Between East and columns 59 and 60, with one between West Sections of the Storage Rack row 4 and 5 and the other between rows Cells 12 and 13 (grid is depicted on Figure 1, I

SFP Schematic Diagram).

14 1-04-02a Liner General Area The Fuel Rack Floor area bounded by Fuel Rack Area Floor - General the grid coordinates 50-01, 50-16, 71-16 and 71-01 and Peripheral Cell Racks 1 -

45, inclusive and as depicted on Figure 1, SFP Schematic Diagram.

15 1-04-02b Liner General Area The Cask Pit Floor area as depicted on Cask Pit Area Floor - General Figure 1, SFP Schematic Diagram.

16 1-04-02c Liner General Area The Energy Absorber Floor area as Energy Absorber Area Floor -

depicted on Figure 1, SFP Schematic General Diagram.

17 1-04-02d Liner General Area The SFP Sump located in the Cask Pit SFP Sump Floor area as depicted on Figure 1, SFP Schematic Diagram.

18 1-04-02e Liner General Area The SFP Sump Drain Line is attached to SFP Sump Drain Line the SFP Sump that is located in the Cask Pit Floor area (depicted on Figure 1, SFP Schematic Diagram).

19 1-04-02f Liner General Area The SFP Skimmer Pipes located along SFP Skimmer Pipes the north wall of the SFP as depicted on Figure 1, SFP Schematic Diagram.

20 1-04-02g Liner General Area The SFP suction piping and valves SFP Suction Piping, Foot Valve &

located in the northeast comer and Discharge Piping (SFP Discharge piping located in the northwest Recirculation) and southwest comers (SFP depicted on Figure 1, SFP Schematic Diagram).

44

TABLE 4.1-1 SPENT FUEL POOL (SFP)

GLOBAL INSPECTION PLAN (PHYSICAL INSPECTION)

SCENARIO DESCRIPTIONS AreaSNMP/

Area or Item to be Description & Location of Item No. Scenario No.

Examined ArealItem SAP8065936

- 21 1-04-02h Liner General Area The SFP Liner & Wall Juncture (Corner SFP Liner & Wall Juncture (Comer Areas - 4 Locations) located in the Areas - 4 Locations) northeast, southeast, southwest, and northwest corners of the SFP as depicted on Figure 1, SFP Schematic Diagram.

22 1-04-021 Liner General Area The Fuel Transfer Basket Rack Area -

Fuel Transfer Basket Rack Area -

General located in the southwest portion General of the SFP as depicted on Figure 1, SFP Schematic Diagram.

23 1-04-03a Containers The Interim Storage Container (ISC)

ISC -1

- Red designated by the red colored identification tag and marked with the numeral 1 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

24 1-04-03b Containers The Interim Storage Container (ISC)

ISC Blue designated by the blue colored identification tag and marked with the numeral 2 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

25 1-04-03c Containers The Interim Storage Container (ISC)

ISC Green designated by the green colored identification tag and marked with the numeral 3 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

26 1-04-03d Containers The Interim Storage Container (ISC)

ISC Yellow designated by the yellow colored identification tag and marked with the numeral 4 that is located on the Energy Absorber (depicted on Figure 1, SFP Schematic Diagram).

27 1-04-03e Containers The Interim Storage Container (ISC)

ISC Brown designated by the brown colored identification tag and marked with the

.numeral 5 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

4-5

TABLE 4.1-1 SPENT FUEL POOL (SFP)

GLOBAL INSPECTION PLAN (PHYSICAL INSPECTION)

SCENARIO DESCRIPTIONS Area!

SNMP Area or Item to be Description & Location of Item No. Scenario No.

Examined Arealftem S__

A P8065936 I__

28 1-04-03f Containers The Interim Storage Container (ISC)

ISC Orange designated by the orange colored identification tag and marked with the numeral 6 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

.29 1-04-03g Containers The Interim Storage Container (ISC)

ISC Pink designated by the pink colored identification tag and marked with the numeral 7 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

30 1-04-03h Containers The Interim Storage Container (ISC)

ISC Purple designated by the purple colored identification tag and marked with the numeral 8 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

31 1-04-03i Containers The Interim Storage Container (ISC)

ISC Red/White designated by the two-tone red/white colored identification tag and marked with the numeral 9 that is located on the Energy Absorber (depicted on Figure 1.

SFP Schematic Diagram).

32 1-04-03J Containers The Interim Storage Container (ISC)

ISC Blued8hite designated by the two-tone blue/white colored identification tag and marked with the numeral 10 that is located on the Energy Absorber (depicted on Figure 1, SFP Schematic Diagram).

33 1-04-03k Containers The Interim Storage Container (ISC)

ISC Green/White designated by the two-tone green/white colored identification tag and marked with the numeral 11 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

34 1-04-031 Containers The Interim Storage Container (ISC)

ISC Yellow/White designated by the two-tone yellow/white colored identification tag and marked with the numeral 12 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

4-6

TABLE 4.1-1 SPENT FUEL POOL (SFP)

GLOBAL INSPECTION PLAN (PHYSICAL INSPECTION)

SCENARIO DESCRIPTIONS SNMP Area!

Area or Item to be Description & Location of Item No. Scenario

o.

Examined Arealltem

____SAP8065936 35 1-04-03m Containers The Interim Storage Container (ISC)-

ISC Brown/White designated by the two-tone brownlwhite colored identification tag and marked with the numeral 13 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

36 1-04-03n Containers -

The Interim Storage Container (ISC)

ISC Orange/White designated by the two-tone orange/white colored identification tag and marked with the numeral 14 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

37 1-04-03o Containers The Interim Storage Container (ISC)

ISC Pink/White designated by the two-tone pink/white colored Identification tag and marked with the numeral 15 that is located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

38 1-04-03p Containers The Interim Storage Container (ISC)

ISC Purple/White designated by the two-tone purple/white colored Identification tag and marked with the numeral 16 that is located in the Cask Pit/Channel area (depicted on Figure 1. SFP Schematic Diagram).

39 1-04-03q Containers The Fuel Transfer Basket A area located Fuel Transfer Basket A & Under in the southwest portion of the SFP as Basket depicted on Figure 1, SFP Schematic Diagram.

40 1-04-03r Containers The Fuel Transfer Basket B area located Fuel Transfer Basket B & Under in the southwest portion of the SFP as Basket depicted on Figure 1, SFP Schematic Diagram.

41 1-04-03s Containers The Fuel Transfer Basket C area located Fuel Transfer Basket C & Under in the southwest portion of the SFP as Basket depicted on Figure 1, SFP Schematic Diagram.

42 1-04-03t Containers, The UD-6N Fuel Assembly Box located UD-6N Fuel Assembly Box in -Peripheral Rack Cell 32 as depicted (including contents) on Figure 1, SFP Schematic Diagram.

-The former UD-6N container is on the

._-_.___-_-east inspection platform.

4-7

TABLE 4.1-1 SPENT FUEL POOL (SFP)

GLOBAL INSPECTION PLAN (PHYSICAL INSPECTION)

SCENARIO DESCRIPTIONS Area/

SNMP Area or Item to be Description & Location of Item No. Scenario No.

Examined Area/Item SA P8065936 43 1-04-03u Containers Failed Fuel Cans (1 - 4) are currently Failed Fuel Cans (4) known as the Storage Containers 1 - 4.

One of the four cans in the SFP has been filled with cut-up incore detectors and the other three remaining cans are empty.

44 1-04-03v Containers The Central Storage Container (CSC)

Central Storage Container (CSC) that is located in the Cask Pit/Channel (Unclad Fuel Fragment Container area (depicted on Figure 1, SFP (UFFC) & Fuel Fragment Schematic Diagram). In addition there Container (Fuel Frag))

are two other containers - UFFC & Fuel Frag that hold the clad and unclad fuel fragments that have been found in the SFP.

45 1-04-03w Containers The Pellet Catcher that is located in the Pellet Catcher Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

46 1-04-03x Containers Inspect the Transitory Interim Storage Transitory ISCs Containers (ISC) designated by the two-tone red/black colored identification tag and marked with the numeral 17, the two-tone blue/black colored identification tag and marked with the numeral 18, the two-tone green/black colored identification tag and marked with the numeral 19, and the two-tone yellow/black colored identification tag and marked with the numeral 20 that are all located in the Cask Pit/Channel area (depicted on Figure 1, SFP Schematic Diagram).

47 1-04-04a Miscellaneous Poison Curtain Rack I (Slots 1 - 60) is Poison Curtain Rack I & Under located on the Energy Absorber as*

Rack depicted on Figure 1, SFP Schematic Diagram.

48 1-04-04b Miscellaneous Poison Curtain Rack 2 (Slots 61 - 120) is Poison Curtain Rack 2 & Under located on the floor area adjacent to the Rack Energy Absorber (depicted on Figure 1, SFP Schematic Diagram).

49 1-04-04c Miscellaneous Work/linspection Platform is located on Work/Inspection Platform (On, the South Wall of the SFP (depicted on Underneath & Behind) - South Figure 1, SFP Schematic Diagram).

Wall 4-8

TABLE 4.1-1 SPENT FUEL POOL (SFP)

GLOBAL INSPECTION PLAN (PHYSICAL INSPECTION)

SCENARIO DESCRIPTIONS SNMP Area!

SNo.

Area or Item to be Description & Location of Item No. Sario Examined Arealltem A P8065936 50 1-04-04d Miscellaneous Work/linspection Platform is located on Work/inspection Platform (On, the East Wall of the SFP as depicted on Underneath & Behind) - East Wall

-Figure 1, SFP Schematic Diagram.

51 1-04-04e Miscellaneous Energy Absorber is located on the South Energy Absorber (Undemeath, Wall of the SFP as depicted on Figure 1, Between -West & South Walls &

SFP Schematic Diagram.

On Top) 52 1-04-04f Miscellaneous Channels are stacked on the floor area of Channels (On, Between, the Cask Pit/Channel as depicted on Underneath & In)

Figure 1, SFP Schematic Diagram.

53 1-04-04g Miscellaneous Dummy Fuel Assembly is located in Dummy Fuel Assembly Transfer Basket C (depicted on Figure 1, SFP Schematic Diagram).

54 1-04-04h Miscellaneous Channel Stripper is attached to and is Channel Stripper (On, Behind, located on the south wall of the SFP as Underneath & In) depicted on Figure 1, SFP Schematic Diagram.

55 1-04-04i Miscellaneous Resin Bed was located in the northwest Resin Bed (On,-Behind, comer of the SFP (depicted on Figure 1, Underneath & In)

SFP Schematic Diagram).

56 1-04-04J Miscellaneous Operating Sources are located in Operating Sources (North End of Peripheral Cells location 3 and 4 SFP)

(depicted on Figure 1, SFP Schematic Diagram).

4-9

______________i.

ilL.

FIGURE 1 HBPP UNIT 3 SPENT FUEL POOL SCHEMATIC CONFIGURATION FOR PHYSICAL INSPECTIONS SPENT FUEL POOL SCHEMATIC DIAGRAM 4-10

Implementation and execution of the Inspection Plan required coordination among the Project and personnel from HBPP. The vast majority of the inspections and examinations were performed using underwater cameras. The camera inspections and examin'tions were supplemented by fuel inspection equipment, and other.devices. The area beneath the spent fuel storage racks were inspected using a combination of re'motely controlled and manually controlled cameras. These inspections and examinations also required expert.

utilization of various pieces of uriderwater lighting equipment to enhance visibility in the pool. Some examinations of specific items' involved the use of radiation survey meters to determine the radiation levels of the items and confirm the presence or lack thereof of the fuel rod segments. The team inspected the accessible locations of the SFP, including the free space in the pool.

Although the plan required the inspection of many areas in the SFP, it did not contemplate the inspection of every fuel assembly or item in the pool. Composite DVDs made in 2000 that documented the examination of the spent fuel asserblies in support of a dry fuel storage' initiative for HBPP were closely reviewed to determirieif in fact the three fuel rod segments or portions thereof could somehow be in any of the fuel assemblies.

The team identified certain locations in the pool as potentially having a greater likelihood of containing one or more' of the fuel rod segments or portions thereof, as well as areas that had the potential for containing unaccounted for fuel rods.

For example:

General Electric (GE) had previously removed a number of individual fuel rods from spent fuel assemblies for examination at the Vallecitos Nuclear Center. The team identified those assemblies with removed fuel rods and confirmed that the removed 'rod count was correct and properly documented.

• The team also considered it possible that the three fuel rod segments or the pipe container could be stored in the UD-6N box, a special container that holds the damaged UD-6N fuel assembly in a storage rack in the SFP. The team opened the box and docurenited its content on various DVDs. The inspection showed that there were fuel rod fragments in the box, but none were 18-inch long fuel rod segments.

• The team conducted an inspection of the free space in the SFP, including the areas under and between the"fuel storage racks.

• The inspections and examinations of locations and items, the review of the fuel assembly DVDs, and the examination of free space in the SFP did not locate the three fuel rod segments in an intact form or the canister they were initially stored in.

4-11

l11L1 Although comprehensive, the execution of the Inspection Plan does not permit a conclusion that the three fuel rod pieces, or remnants of the rods, are not in the SFP. Based on findings regarding the fragments found during the Inspection Plan (see Section 4.7 of this Final Report), it is possible that fuel rod fragments found could be portions of the A-49 fuel rod segments in broken form. In addition, a final determination as to all areas of the SFP will not be possible until all 390 fuel assemblies, storage containers and other items, and other obstructions are removed from the SFP. As noted, the Inspection Plan addressed the areas that the team considered capable of accommodating the three fuel rod segments or the pipe container. It did not address every possible place that the segments or fragments of the segments could be. Some less likely places were also not addressed because inspections were done earlier. For example:

o The team did not physically examine, disassemble, or inspect the rods of each of the 390 fuel assemblies in the SFP for the presence of the three fuel rod segments, since a thorough inspection of the fuel assemblies had for the most part been performed in 2000 as a preparatory activity for dry cask storage of the HBPP spent fuel assemblies.

o During the performance of TP 2004-01, "Boral Can External Inspection,"

each fuel assembly, with its Boral can attached, was removed from its storage rack cell and the cell inspected for fuel fragments, one of which was found and documented. The inspection was documented on video and with data sheets. The presence of the fuel rod segments or the pipe container would have been identified during this process.

o Based on the results of the Inspection Plan, the possible physical configurations of the A-49 fuel rod segments and the presence of non-fuel SNM in the SFP, the following has been concluded:

For Physical Configurations A, intact approximately 18-inch long segments, it is "Highly Unlikely" that any of the Plan locations and items contain the subject A-49 segments.

For Physical Configuration B, damaged (broken, crushed, or cut segments (i.e., fragments) it is "Reasonably Possible" that one or more of the Plan locations and items specifically contain fuel fragments that may be associated with the subject A-49 segments (see Section 4.7 of this Final Report).

For Physical Configuration C, fuel rod segments in a canister (or pipe);

it is "Highly Unlikely" that any of the Plan locations and items contain the A-49 segments.

For Physical Configuration D, fuel fragments not specifically identified 4-12

as being from A-49 and non-fuel SNM, it is "Confirmed" that one or more of the' Plan locations and items contained fuel fragments and non-fuel SNM.

With regard to Physical Configuration D, it is also "Reasonably Possible" that all or some of the three A49 fuel rod segments and their remnants may still be in the SFP as fragments rather than segments. This possibility is based on the observation that some fuel rod fragments found in the SFP during tbe physical inspection activities exhibit various characteristics that are indicative of the three unaccounted for A49 fuel rod segmrients and their remnants (see Section 4.7 of this Final Report).

There were'a total of 175 fuel fragments that were collected and stored in-one of two special containers (designated as the Fuel Fragment Storage Container and the Unclad Fuel Fragment Storage Container) located in the SFP. Prior to placement in the containers, each'of the fragments were identified, measured, characterized, categorized, and evaluated. The fragments have been captured on video and tallied in Pacific Gas and Electric Company (PG&E) Calculation NX-288'. The vast majority of the 175 fuel fragments were located in the Central Storage Container (CSC) in'the SFP.', Historically, the CSC was utilized as the primary repository for fuel fragments and other small radioactive items found in the SFP. During the'search for A-49fuel 'rod segments during 2004 -2005, five fragments were found in Failed Fuel Can' number one (FFC #1), one in the SFP sump, one on the floor of the SFP, and eight in the container that housed damaged fuel assembly UD-6N.

In conclusion, the inspection of SFP locations and the examination of SFP items was both focused and comprehensive, targeting those locations and items within the pool that were the most likely storage locations for the fuel rod segments or the pipe container. The results of these inspections established that, subject to the limitations of each search, the intact fuel rod segments and/or the pipe container are not in locations searched., But given the limitations and conditions discussed earlier, the inspections-and examinations cannot rule out the possibility that the fuel rod segments remain in the SFP in either an uninspected location, an unexamined item, or.as part of the fuel fragments that were found.

Therefore, it is 'Reasonably. Possible" that all or some of the three A-49 fuel rod segments may still be in the SFP1'Ohder PG&E's physical control as fragments rather than segments.

4.2 ONSITE INSPECTIONS OUTSIDE THE SFP Inspections of possible locations outside the HBPP Unit 3 SFP were performed in an attempt to'locate the threee missing 18-inch fuel rod 'segments cut from fuel assembly A-49, fuel fragments,' or'any other special nuclear material. The inspections were'performed in'accordarnce with a pre-approved plan and PG&E Calculation NX-288, Documentation of Spent Fuel Fragments, Revision 6, April 21, 2005 4-13

included locations in the Unit 3 refueling building (RFB), Unit 3 power building, and Unit 3 yard and ancillary buildings. In most areas, a visual search for containers (casks) large enough to radioactively shield irradiated SNM and dose rate measurements were sufficient to rule out the presence of the fuel rod segments, fuel fragments, and any other SNM. In some cases, documented previous inspections and/or indirect methods were used to confirm absence of the fuel segments, fuel fragments, or other SNM.

The inspection plan addressed all of the Unit 3 and HBPP site areas of interest outside of the SFP that were identified as having the space required for storing shielded containers or possessing water-filled areas that are capable of accommodating the pipe container and/or fuel rod segments in various configurations. The plan was divided into three parts: RFB, power building, and yard and ancillary buildings. Two primary criteria were used to rule out the presence of SNM in the locations searched:

Criterion 1 - If a radiological survey of the location indicated dose rates of less than 200 mRlhr, then it was concluded that SNM could not reside in that location outside of a shielded cask or water filled container/area.

Current dose rates throughout the plant are typically less than 10 mRlhr based on routine surveys. Discovery of a dose rate greater than 200 mR/hr would indicate radioactive material not typically found outside the SFP.

Criterion 2 - If, coupled with Criterion 1 being met, a visual inspection of the location did not identify a shielded cask or water-filled container/area suitable for storage of the fuel rod segments, fuel fragments, or other irradiated SNM, then it was determined that the location did not contain any SNM. A cask with a wall thickness equivalent to 0.4-inch thickness of lead, approximately 24 to 36 inches long and 12 to 18 inches in diameter, would be required to effectively shield the fuel rod segments, fuel fragments, or other irradiated SNM. A cask of this size would be visually obvious to an inspector.

Several areas of interest were either currently inaccessible, or could be effectively addressed through evaluation and/or review of documentation of previous inspections that definitively ruled out the presence of SNM. The plan took credit for physical inspection activities that had already been completed and adequately documented.

HBPP procedures have historically precluded storage of irradiated SNM in plant areas outside of the SFP. Notwithstanding these procedural constraints, it was considered necessary to thoroughly search all nearby plant areas to ensure the fuel rod segments, fuel fragments, or other irradiated SNM had not been purposely or inadvertently diverted to a location outside the SFP. The most likely places outside the SFP where SNM might be found were believed to be in the 4-14

reactor vessel (cannot presently be inspected), in the high level vaults, in the low level storage building, and in the rew fuel storage vault. Beyond these prime areas, the scope of the inspections was expanded to include all potential locations outside the SFP where'the'18-inch fuel rod segments, fuel fragments, or other SNM might be located.

The inspections were performed and the results reviewed and approved in the.

pe'riod of January 12,;2005, through' February 4, 2005. The inspection plan and inspection checklist were annotated to 'document the results of the inspections performed. The inspectors filled out the inspection checklist while in the field (initialed each item as the inspection progressed and, where appropriate, made notes of any relevant comnients):. The che'cklists'and detailed findings were included in the Interim Report submtnitted to the NRC on February 22, 2005 (Enclosure 3 to PG&E Letter HBL-05-001).

The inspections for locations outside the SFP in Unit 3 or in the vicinity of Unit 3 did not result in the discovery'of.the fuel rod segments or the pipe container, fuel fragments, or any other SNM. Inspection of several areas of interest, namely the access shaft pipe chase, the reactor vessel, the drywell, and the fuel transfer cask was impractical at this time.' Based on available information, it is believed to be "highly unlikely" that the fuel rod segments, pipe container or fuel fragments are in any of these locations but this cannot be absolutely confirmed until removal of these components during decommissioning.

4.3 LOW LEVEL RADIOACTIVE WASTE SHIPMENTS Based on the documentation gathered and reviewed, and the interviews that were completed, the Project investigation could not disprove that the three fuel rod segments may have been mistaken for irradiated hardware or were in a configuration that was not readily recognizable as the fuel segments, and inadvertently shipped offsite to one or more of three commercial low-level radioactive waste (LLRW) facilities.,

• These facilities are located in Barnwell, South Carolina (Barnwell), Beatty, Nevada (Beatty), and the Hanford Reservation in Richland, Washington (Hanford). Subsequent review of HBPP radioactive waste documentation manifests for shipments 'to the Beatty facility identified two cask shipments that could not be eliminated on the basis of dose rate alone, but nonetheless resulted in the conclusion that the fuel rod segments could not have been contained in any of the Beatty shipments. For'the'shipment made on May 8, 1974, the conclusion was based "on the fact that the waste material did not 'originate from the SFP and it was not credible for the segment to have been in the waste.

The other'shipment to Beatty,'-r-a'de on December.12,1968, was a shielded cask shipment that contained process ed'(segmented) incore detectors from the SFP.

Review of the documentation associated with the subject shipment clearly

• 4-15

indicates that the three 18-inch long segments were not included as a part of the shipment. The shipping manifest and the recorded SNM content only reflected the incores, indicating that no A-49 segments were intentionally included in the shipment. Notes microfilmed with the shipment manifest show an intention to properly report the SNM content of the shipment and the notes indicate that only the SNM in the incores was contained in the shipment. The Project team considered these facts, coupled with the shipment occurring within approximately 10 weeks of the A49 segmentation activity, including the placement of the pipe container on a lanyard hanging in the SFP, as the basis for concluding that it was implausible for either the A-49 segments or the pipe container to be inadvertently included, or intentionally included but not documented in the Beatty LLRW shipment. Accordingly, the Beatty facility was removed from further consideration.

Although there is currently no evidence that the three fuel rod segments were actually shipped to Barnwell or Hanford, it was assumed for the purpose of analyzing the potential public health and safety implications of each scenario that the three fuel rod segments were inadvertently included within a LLRW shipment, transported to the LLRW facility, and subsequently disposed of by burial at either the Barnwell or Hanford LLRW facility.

Barnwell HBPP made a total of four low-level radioactive waste shipments to the Barnwell facility since HBPP was licensed for operation in August 1962. The following table summarizes those shipments.

LLRW Radioactive Waste Shipments to Barnwell Cask Type of Package Content Volume Curles Liner Date Ship Package Contact Shpd Method (ft3)

(Est)

Dose Rate CNS 3-55 Uner Irradiated Hardware 60 3.1 E+03 800 R/hr 10/11/83 Truck CNS 3-55 Uner Irradiated Hardware 60 1.1E+04 2200 R/hr 10123/83 Truck CNS 3-55 Uner Irradiated Hardware 60 3.8E+03 600 R/hr 111/16/83 Truck CNS 3-55 Uner Irradiated Hardware 60 4.5E+011 1200 R/hr 12/15185 Truck The Project team utilized the various evaluation criteria developed for LLRW shipments and other direct shipments (ODS) to assess the Barnwell LLRW shipments. It was determined that all of the Barnwell LLRW shipments are potential candidates for having held the fuel rod segments based on documentation, manifested content, packaging process and method, and use of a shielded cask.

In 1983 and 1985, HBPP implemented a number of programs to reduce the amount of irradiated hardware and radioactive waste in the Unit 3 SFP. This was done for two purposes: (1) there was the potential that either Barnwell and/or Hanford would stop accepting LLRW shipments, and (2) HBPP wanted to make 4-16

shipments before the more stringent requirements and standards of 10 CFR 61 were implemented for LLRW shipments;.

As noted earlier, the'documentation evidence and interviews do not establish either the location or condition of the fuel rod segments after September 1968.

This uncertainty creates at leastihe' possibility that workers could have unintentionally loaded the fuel rod segments or the pipe container into any of the Barnwell liners before shipping the shielded casks (referred to as CNS 3-55 casksj in 1983 and 1985. The inventories and related documents for each of the shipments do not provide any evidence to support a conclusion that the fuel rod segments were shipped. Rather, the only items reflected in the shipping documents that could have been confused with the fuel rod segments were incores that had previously been cut in 1973. The detailed procedures that PG&E followed,lthe related documentary evidence of procedural compliance and interviews, establish'that PG&E loaded cut incores and not the fuel rod segments or the pipe container.

October 11, 1983, Shipment This shipment is the first in a series of three cask'shipments to Barnwell, all of which contained irradiated hardware from'the SFP. The protocol used to determine the radioactivity content of the cask liner consisted of a determination of the mass and surface area of the item, followed by a calculation to determine the activation and contamination nuclides. Unidentified items would not have been included in the shipment without some effort to' quantify and record the item

'mass, areas,'and dose rate. The manifested content list for this'shipment can be inferred from the spreadsheets that were developed and used to calculate the radioactive contents. The spreadsheet printout indicates that the shipment contained 5 control rod blades, 44'control blade followers, 10 "wide" poison curtains, and 2 "narrow" poison curtains." In spite of the documentation to the contrary, and because of the high dose rates from the neutron activated components and the underwater loading process, it is possible but unlikely that this shipment contained one or more of the A-49 fuel rod segments or the pipe

'container'with the' rod segments inside.

October 23, 1983, Shipment The second in.a series of three cask shipments to Barnwell also contained irradiated hardware from the SFP. The-same protocol was used to determine the

'radioactivity'content of the cask lin er as for the October 11, 1983, shipment.

Again, unidentified items'would rot have been included in the shipment without some effort to qjuantify and 'record the item mass, areas,'and dose rate.' The manifested content list for this shipment can.be inferred from the spreadsheets that were 'developed and used to calculate the radioactive contents;' The spreadsheet printout indicates that the'shipment containdd7 control rod blades, I control blade follower, 12 "Wid" poison curtains, 16 fuel assembly channels, 4-17

i L-8 reactor core plugs, 7 neutron windows, and "trash" (used as shoring to reduce load movement within the cask liner). The 'trash" is further described and defined in documentation as 5 control rod drive filters, a one foot square steel plate (0.25-inch thick), a one foot square aluminum plate, a "support" (estimated at 80 lb), and a piece of pipe (3/4-inch schedule 40). In spite of the documentation to the contrary, and because of the high dose rates from the neutron activated components and the underwater loading process, it is possible but unlikely that this shipment contained one or more of the A-49 fuel rod segments or the pipe container with the rod segments inside.

November 16,1983, Shipment The last shipment of this series of three cask shipments to Barnwell also contained irradiated hardware from the SFP. The same protocol was used to determine the radioactivity content of the cask liner as for the October 1, 1983, shipment. Again, unidentified items would not have been included in the shipment without some effort to quantify and record the item mass, areas, and dose rate. The manifested content list for this shipment can be inferred from the spreadsheets that were developed and used to calculate the radioactive contents. The spreadsheet printout indicates that the shipment contained 4 control rod blades, 1 control blade follower, 17 "wide" poison curtains, 17 fuel assembly channels, 1 guide tube, and 'trash" (used as shoring to reduce load movement within the cask liner). The 'trash" is further described and defined in documentation as a 2-foot section of sparger pipe, reactor sample coupon racks, sparger clamps/bolts/nuts, and an empty bucket. In spite of the documentation to the contrary, and because of the high dose rates from the neutron activated components and the underwater loading process, it is possible but unlikely that this shipment contained one or more of the A-49 fuel rod segments or the pipe container with the rod segments inside.

December 15,1985, Shipment This shipment was a single shipment that was similar in nature to the 1983 series of Bamwell shipments. This shipment also contained irradiated hardware from the SFP, and the same protocol was used to determine the radioactivity content of the cask liner as for the October 11, 1983, shipment. Again, unidentified items would not have been included in the shipment without some effort to quantify the item mass, areas, and dose rate. The manifested content list for this shipment can be inferred from the spreadsheets that were developed and used to calculate the radioactive contents. The spreadsheet printout indicates that the shipment contained 10 reactor chimney racks (15 lb, 1.6 - 128.3 R/hr), 4 control rod brackets (45 lb, 1 - 6 R/hr), 2 storage cans (possibly misidentified failed fuel cans, 65 - 115 lb, 23.4 - 28.3 R/hr), 7 dummy fuel assemblies (possibly a combination of dummy fuel assemblies, reactor core plugs & neutron windows, 35 - 140 lb, 139 - 580 R/hr), 2 'pipe barrels" (195 - 250 lb, 69 - 235 R/hr), a

'hold down device" (25 lb, 30 R/hr), and 3 sets of 'processed incores" 4-18

(totaling 1520 inches, 18 - 38 lb, 69 - 219 R/hr). In spite of the documentation to the contrary, and because of the high dose rates from the neutron activated components and the underwater loading process, it is possible but unlikely that this shipment contained one or more of the A-49 fuel rod segments or the pipe container with the rod segments in'side.

Barnwell Summary There was opportunity for the loading of additional items that precludes the categorical exclusion of all the Bamwell shipments and, as has already been established, reports in 1985 indicated that'Barnwell and Hanford LLRW facilities might be closing provided a possible incentive for PG&E to want to load additional material in the shipments. The physical dimensions of the Bamwell liners do not effectively preclude'the'shipment of either the three fuel rod segments or the pipe container. Simply stated, the liners had more than enough room to accommodate either the fuel rod segments or the pipe container.

However, having the motive and opportunity to load additional material does not make it so. Workers would have had no'reason to violate procedures and regulatory requirements by loading additional materials and not recording it on the shipping manifest and documentation.

The available information supports the conclusion that neither the fuel rod segments nor the pipe container were loaded in any of the Bamwell shipments as the investigation found no evidence that either the fuel rod segments or the pipe container were placed in 'any of the'liners and shipped to the Barnwell LLRW facility.

The investigation did not produce clear evidence of the specific location of the three fuel rod segments or the pipe container. There is no evidence indicating that the fuel rod segments or the pipe container were shipped to Barnwell. An

'opportunity for the inadvertent shipment of either the segments or the pipe container, however, existed to some small degree in each of the three 1983 and one 1985 Bamwell shipments. The likelihood of an inadvertent loading of the segments or pipe container is "Possible,'But Not Likely."

Hanford HBPP made more than 100 cask shipments of low-level radioactive waste shipments to the Hanford facility since HBPP was licensed for operation in August 1962. The Project team utilized the various evaluation criteria developed for ODS and LLRW shipments to uscreen-out" a significant number of the Hanford LLRW shipments. Thirteen of those shipments were potential' candidates for having held the fuel rod segments based on documentation, manifested content, packaging proces's and method, and use of a shielded cask.

Eight of those shipments were elim'inated based on the fact that the waste 4-19

SLe material did not originate from the SFP and it was not credible for the fuel rod segments to have been in the waste.

The following table summarizes the remaining five shipments:

LLRW Radioactive Waste Shipments to Hanford Container Type of Package Content Volume Curies Contact Date Ship Package (fts)

(Est)

Exp. Rate Shpd Method 8-120B Liner Filters 126 5.1E+01 1.6E+04 1120/86 Truck 8-120B Uner Drums, Filters, Trash 126 4.1E+01 1.3E+04 1/28/86 Truck 8-120B Liner Filters, Cartridges 126 5.9E+01 3.1 E+04 2/5/86 Truck 8-120B Uner Filters, Cartridges 126 4.6E+01 3.OE+04 2118/86 Truck 8-120B uner Filters, Cartridges 126 4.8E+01 2.3E+04 3/4186 Truck As noted earlier, the documentation evidence and interviews do not establish either the location or condition of the fuel rod segments after September 1968.

This uncertainty creates at least the possibility that workers could have unintentionally loaded the fuel rod segments or the pipe container into any of the Hanford shipments before shipping the casks. The inventories and related documents for each of the shipments, however, do not provide any evidence to support a conclusion that the segments were shipped. Rather, the filters, filter cartridges, filter bags, trash, and other miscellaneous items reflected in the shipping documents could have held or 'masked' the presence of the fuel rod segments and/or pipe container. Nevertheless, the detailed procedures that PG&E followed, the related documentary evidence of procedural compliance, and personnel interviews, establish that PG&E was diligent in their LLRW processing, packaging, and shipping activities.

January 20, 1986, Shipment This shipment contained two drums, one of filter cartridges with a surface dose rate of 30 mRlhr, and one of vacuum filter bags with a contact dose rate of 16.3 R/hr and a weight of 225 lb. The package also included two stainless steel cartridge filters, with surface dose rates of 14 R/hr and 4.2 R/hr, and weights of 170 lb and 125 lb. These items were placed in a partially grouted liner, which was in turn grouted solid, for shipment in a cask for disposal. The screening tool dose rate for a drum of 225 lb is about 10 R/hr, which does not preclude the presence of an A-49 segment in the highest dose rate filter canisters or drum.

January 28,1986, Shipment This cask shipment contained a drum of compacted trash, a drum of filter bags from SFP vacuuming, and five filter canisters individually grouted, that were then placed in a partially grouted liner. The liner was then completely grouted and placed in the cask for shipment to and eventual burial at the LLRW. The drums in the liner had weights of 100 - 265 lb and associated dose rates of 450 mR/hr-4-20

13 R/hr. The screening tool dose rate for the heaviest drum of 265 lb is 10 R/hr.

It is therefore not possible to determine from the dose rate alone whether there was an A-49 segment in this shipment.

' February 5, 1986, Shipment This cask shipment contained a 'drum of cellulose radwaste filters, 6 filter cartridges in a bag, and 10 stainless steel filter cartridges from SFP'_vacuuming individually grouted, that were thenr placed in a partially grouted liner. 'The liner was then completely grouted and placed in the cask for shipment to and eventual burial at the LLRW. The items in the'liner had weights of 20 - 175 lb and associated dose rates of 300 mr/hr-31.3 R/hr. The screening tool dose rate is conservative for smaller items, and the dose rate for a drum of 70 lb is 15 R/hr.

Since the dose rate for some of the filters exceed this level, it is therefore not possible to determine from the dose rate alone whether there was an A-49 segment in this shipment.

February 18,1986,'Shipment This shipment contained 2 drums of filters and filter media, two sets of 6 filter cartridges,.5 stainless steel filter, cartridges, a small bucket, and a square aluminum box. These items were 'placed in a partially grouted liner, which was then completely grouted and placed in the cask for shipment to and eventual burial 'at the LLRW. The items in the liner had weights of 125 - 275 lb and associated dose rates of 120 mR/fir-30 R/hr. The screening tool dose rate is conservative for smaller items, and the screening dose rate for a drum of 275 lb is 10 R/hr. Since the dose rate for some of the filters exceed this level, it is therefore not possible to determine from the dose rate alone whether there was an A-49 segment in this shipment.

March 4,1986, Shipment This cask shipment contained a 55-gallon drum, three sets of 6 filter cartridges, 5 stainless steel cartridges, a small vacuum bag, 2 larger filter bags, an aluminumtray, and a carbon steel Ihopper'can" with an extension. These items were' placed in a partially grouted liner that was then completely grouted and placed in the cask for shipment to and eventual burial at the LLRW. The items in the liner had weights of 25 - 175 lb and associated dose rates of 2 -7 23 R/hr.

The screening tool dose rate is conservative for smaller items, and the dose rate for a drum of 75 lb is 13 R/hr. Since the dose rate for some of the filters exceed this level, it is therefore not possible to determine from the dose rate alone

.whether there was an A-49 segmentt in this shipment.

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______M.r Hanford Summary The available information supports the conclusion that neither the fuel rod segments nor pipe container were loaded in any of the Hanford shipments, as the investigation found no evidence that either the fuel rod segments or the pipe container were placed in any of the liners and shipped to the Hanford LLRW facility. An opportunity for the inadvertent shipment of either the segments or the pipe container, however, existed to some small degree in each of the five Hanford shipments. The likelihood of an inadvertent loading of the segments or pipe container is "Possible, But Not Likely."

Overall LLRW Shipment Conclusion It is plausible that an opportunity for the inadvertent shipment of the rod segments and/or the pipe container existed in shipments from the SFP because workers who may have been unfamiliar with materials and items in the SFP, or had to deal with visibility issues in the SFP, inadvertently loaded the fuel rod segments and/or the pipe container in a LLRW shipment. However, there is no evidence that the fuel rod segments and/or the pipe container were shipped to either the Barnwell or Hanford LLRW facilities. An opportunity for the inadvertent shipment of either the segments or the pipe container, however, existed to some small degree in each of the three 1983 and one 1985 Barnwell shipments or the five 1986 Hanford shipments. The likelihood of an inadvertent loading of the segments or pipe container is therefore 'Possible, But Not Likely" for both LLRW facilities.

4.4 OTHER DIRECT SHIPMENTS Other Direct Shipments (ODS) are defined as radioactive material shipments that are made from HBPP to another licensee. The majority of ODS shipments differ from LLRW shipments for the primary reason that the radioactive material being shipped is not waste, but is material that will be utilized or processed which requires unpacking and handling of the material. In other words, if the three fuel rod segments or pipe container were present in the ODS shipment, the receiving licensee would have found and identified the missing fuel rod segments since they were not expected to be a part of the shipment to the licensee. This is not the case for a LLRW shipment which would simply be removed from its transportation container and buried without examination of the LLRW shipment contents.

Therefore, with the exception of the 15 shipments to Nuclear Fuel Services (NFS) discussed below, it can be reasonably concluded that it is highly probable that the three fuel rod segments and/or the pipe container would have been found and identified in any of the ODS shipments made by HBPP. Accordingly, all of the HBPP made ODS shipments were "screened out" as not being plausible with the one above noted exception.

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There were 15 ODS shipments to NFS at West Valley, New York that, due to their unique nature, could have possibly contained either the three fuel rod segments and/or the canister, and they would not necessarily have been found or identified. The 'exception" ODS shipments are summarized as follows:'

Other Direct Shipments Destination.

Container Package.

Curies Contact Exp.

Date Saipd Ship Method Content (Est)

Rate (mR/hr)

NFS NFS M-100 Spent Fuel 1.18E+06 1.80E+01 5/14/69 Train NFS NFS M-100 Spent Fuel 1.14E+06 1.00E+01 6/17/69 Train NFS NFS M-100 Spent Fuel 8.78E+05 1.00E+01 8/6/69 Train NFS NFS M-100 Spent Fuel

.7.26Ee05

<1.00E+01 11/5/69 Train NFS NFS M-100 Spent Fuel 1.68E+06

<1.00E+02 6/23/70 Train NFS

• NFS M-100

-Spent Fuel 1.80E+06

<6.00E+00 7/2711O Train NFS NFS M-100 Spent Fuel 7.10E+05 2.00E+00 8/31/70 Train NFS NFS M-100 Spent Fuel 5.60E+05

<7.OOE+00 10/8/70 Train NFS NFS M-100 Spent Fuel 4.20E+06 5.00E+00 11/5170 Train NFS NFS M-100 SpentFuel 4.11E+06 5.00E+00 12/2/70 Train NFS NFS M-100 Spent Fuel 3.97E+06 4.50E+00 1/5/71 Train NNFS FS M-100 Spent Fuel 2.13E+06 4.00E+01 2/5/71 Train NFS NFS M-100 Spent Fuel 5.81E+05 5.00E+00 3/26/71 Train NFS NFS M-100 Spent Fuel 8.19E+05 6.00E+00 4/29/71 Train NFS NFS M-100 Spent Fuel 7.49E+05 1.00E+01 613/71 Train All of the "exception" shipments are associated with the'shipment of spent nuclear fuel to NFS for reprocessing at West Valley, New York, in the period 1969 - 1971.' Of the 183 identified ODS shipments, only the 15 NFS shipments did not fully' meet the definitionr of an ODS shipment. The specific exception is associated with the assumption that the receiving licensee, NFS, would have found and identified the missing fuel rod segments since they were not expected to be a part of the shipment to the licensee. NFS was expecting-full fuel assemblies based on the documentation that has been identified and reviewed by the Project team. However, of the 270 fuel assemblies that were sent to NFS, 189 were GE Type I, stainrless-ste~el clad assemblies that had experienced significant operational damage due to inter-granular stress corrosion cracking (IGSCC) of the fuel rod cladding. A March 1967 report'that documented the visual inspection and shipping results'of 50 of the Type I fuel assemblies indicated that 35 assemblies we're defective and 13 were suspected of having defects. A subsequent report, also'written in 1967, indicated that the number of assemblies classified as defective was now 60 and 3 additional assemblies were suspected of having defects. The 1966 Annual Operations Summnary Report stated that 106 of the total 189 Type'l fuel assemblies had failures. A significant number of the failed assemblies had either damaged cladding or in some cases missing portions of fuel rods.

The documentation that was prepared by HBPP and transmitted to NFS for each of the 15 'shipments did not indicate the presence of damaged or missing portions of fuel rods. Likewise,-the documentation prepared by NFS 'associated with the receipt of the 15 shipments and the reprocessing of same did not 4-23

indicate the presence of damaged or missing portions of fuel rods. Since it was known and documented that the Type I fuel assemblies were damaged and that portions of fuel rods were missing, and NFS did not indicate receiving damaged fuel assemblies with portions of rods missing in any of their receipt and SNM Control and Accountability documentation, it can be reasonably concluded that NFS did not thoroughly examine the fuel assemblies that they received from HBPP. Accordingly, the team concluded that the fuel rod segments or pipe container could have been included in any of the 15 shipments to NFS and not been detected.

Conclusion This conclusion statement is made based upon the investigative results of this scenario disposition that include facts, circumstantial evidence, supposition, and postulated events that support the plausibility of this scenario. The investigation did not produce any clear and convincing evidence as to the specific location of the three fuel rod segments. There is also no documentary evidence indicating that the fuel rod segments were shipped to NFS for reprocessing. However, interviews of employees who worked at HBPP Unit 3 in the 1960s and subsequent years provided speculative evidence that the three segments went to NFS (i.e., they "believed" that the A-49 fuel rod segments may have been shipped for reprocessing). An opportunity for the inadvertent, or even intentional, shipment of the segments existed to some degree in each of the 15 spent fuel assembly shipments to NFS. PG&E concludes that it is "Possible, But Not Likely," that the three A-49 fuel rod segments were shipped to NFS for reprocessing.

4.5 THEFT OR DIVERSION The theft or diversion scenario considers whether any or all of the three missing 18-inch HBPP fuel rod segments were the subject of theft or diversion, as set forth in the design basis threat provisions of 10 CFR 73. The scenario assumes the three missing fuel rod segments were either stolen from the SFP or diverted to an unknown location outside the SFP. The period of interest bounding this scenario is from September 27, 1968, to the present. The specific beginning date, September 27, 1968, is the date of the last record specifying that the three fuel rod segments were stored in the SFP. Numerous diverse and redundant barriers to theft or diversion of the fuel rod segments existed over the period of interest. These barriers have been identified and analyzed.

The investigations and analyses support the conclusion that the theft or diversion scenario is 'Highly Unlikely."

Three alternatives were considered by the Special Nuclear Material Inventory, Inspection & Control Project Team (SNMP Team or team): theft by an external entity, theft by an insider, and unauthorized disposal.

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4.5.1 THEFT BY AN EXTERNAL ENTITY The first alternative evaluatesitheft of the fuel rod segments by an external entity. This scenario assumes passive or active participation of an insider.

Based on the absence of any known overt forceful attack against HBPP, or any other commercial U.S. nuclear power reactor, this disposition did not evaluate the possibilitydof the theft of the fuel rod segments by an external entity using forceful means.

No evidence was found to indicate that any external entity either attempted or carried out a successful theft of the fuel rod segments.

Further analysis showed'that the integrity of applicable barriers was adequate to deter, prevent, and'det6ct an attempted theft of SNM by an external entity. The fuel rod segments have essentially no economic or strategic value and high radiation levels associated with the spent fuel rod segments present a significant barrier, particularly in the decade following discharge of the fuel from the' core in 1965.

4.5.2 THEFT BY AN INSIDER (AUTHORIZED INDIVIDUAL)2 The second alternative assumes an insider stole the fuel rod segments.

Analysis demonstrated thatthe integrity of applicable barriers was adequate to deter, prevent,'and detect an attempted theft of SNM by an insider. As stated above, thtefuel'rod segments are of little to no economic or strategic value and the radioactive character of the spent fuel rod segments presents a significant barrier in itself.

No evidence was found that any insider attempted or carried out the theft of the fuel rod segments.

4.5.3 UNAUTHORIZED DISPOSAL (DIVERSION)

This third alternative assurmies the Licensee or authorized individual(s) knowingly engaged in activities to dispose of the three fuel rod segments without the appropriate authorization, either on-site or off-site.3 Execution of such a scenario would require the involvement of a skilled person or persons. If multiple individuals were involved, it is unlikely the activity would have remained concealed.

2 Defined as any Individual, Including an employee, who has been granted unescorted access to areas where SNM Is used or stored.

3 If an Individual knowingly, without proper authorlzation.'relocated the fuel rod segments to another location In the SFP, such as a liner or spent fuel storage rack, It Is not considered diversion. If such relocation was not for purposes of Intentionally removing the fuel rod segments from the SFP. If the relocation was for later removal of the fuel rod segments from the SFP for Illicit purposes then the scenario is addressed under 'Theft by an Insider.: If the relocation was for the purpose of unauthorized disposal onsite or offsite. then the scenario Is addressed under-Unauthorized Disposal.!

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IlL.

No evidence was found that the Licensee or authorized individual(s) attempted or carried out a diversion of the fuel rod segments for unauthorized disposal. Additionally, there appears to be no plausible motivation for such actions: no business, corporate, or economic advantage supports unauthorized disposal. The subject fuel rod segments account for a minute fraction of the HBPP SNM inventory for the period of interest. It is unreasonable to postulate that the Licensee, or authorized individuals, would undertake such a risk without a clear and compelling advantage or motive.

Further analyses have demonstrated that the integrity of applicable barriers were adequate to deter, prevent, and detect a willful attempt of unauthorized disposal of the fuel rod segments.

4.5.4 BARRIER ANALYSIS The barrier analysis is based upon a "defense-in-depth" approach, in that applicable barriers, when combined, form an adequate means of deterring, preventing, and detecting any attempted theft or diversion of SNM.

An historical analysis of the applicable barriers was performed. These barriers included administrative, physical plant access, RFB access, control and alarm, SFP access, and transport and disposal site barriers.

The analysis examined the basis, requirements, and HBPP compliance and performance history of each of the barriers.

Because numerous barriers have existed for the period of interest (September 1968 to the present), it was concluded that no single barrier failure, by itself, would permit an undetected theft or diversion of the three fuel rod segments. Based on this conclusion, it was necessary to determine if any multiple barrier failures occurred at anytime during the period of interest, (i.e., failure of multiple layers of defense-in-depth).

Compliance and performance histories for each barrier were analyzed and then compared with information from the other applicable barriers to determine if simultaneous barrier failures occurred. The results of this barrier comparison demonstrated that at no time during the period of interest did multiple barrier deficiencies exist that were sufficient to permit an undetected attempt of theft or diversion of the fuel rod segments.

It is recognized that the relatively short length of the fuel rod segments (i.e., approximately 18 inches), would make the theft or diversion of the segments 'easier' than if they were full-length fuel rods (approximately 84 inches for the HBPP Unit 3 fuel rods). Nonetheless, the results of the barrier analysis support the conclusion that theft or diversion of the fuel rod segments is 'Highly Unlikely."

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4.5.5 OTHER SUPPORTING ANALYSES The investigation'identified the'applicable regulatory requirements, both present and historical, that support the deterrence, prevention, and detection of attempted theft or diversion of SNM. 'The investigation then assessed whether HBPP imiaintained regulatory compliance throughout the period of interest. This evaluation showed that HBPP maintained regulatory compliance necessary to deter, prevent, and detest the attempted theft or diversion of SNM in the form of irradiated fuel rod segments.

Moreover, the team reviewed numerous documents relevant to this scenario investigation and barrier analysis. These records were identified and 'collected from both electronic and hardcopy record searches. The majority of the records identified were used as supporting information in the analysis of the specific barriers. None of the records reviewed provided any evidence of attempted or actual theft or diversion of the subject fuel rod segments, or any other SNM.

The team has conducted approximately 60 in-person or telephone interviews in an attempt t' determine the location of the fuel rod segments. One of the questions the interviewers typically'asked was "Do you have any reason to believe that someone stole the fuel rod segments?" None of the interviewees believed that it was possible for anyone to have stolen the'fuel rod segments. Many'of the interviewees had general, and in sohme cases detailed, knowledge of HBPP security, radiological controls, and RFB access (via general work experience and site access training) to provide credible evidence that theft of the fuel rod segments was 'Highly Unlikely.", The overwhelming perception by interviewees was that the fuel rod segments were far too radioactive to have been stolen.

Finally, the team analyzed the postulated hazards and complexities associated with' an attempted theft of the fuel rod segments and compared these difficulties to the economic value or strategic value of the fuel rod segments. The primary hazard identified was the health effect of acute radiological exposure, particularly'during the 1968-1974 time periods when'there was no form~al security force at HBPP and the SFP was still uncovered. The highl'radiation levels of fuel rod segments would have presented a biological health hazard capable of providing a lethal exposure.' The investigation determined there to be no economic or strategic value that would be sufficient to warrant the risk and complexity of managing such a hazard. Thus, the team determined that the fuel rod segments presented a significant radiological hazard with no apparent economic or strategic be'nefit'during the time they would be most vulnerable to theft or diversion.

4-27

II AL-With time, the radiological hazard associated with the fuel segments slowly decreased. Other barriers, such as increased security presence and security equipment in the time periods of 1974 to 1988, and, in 1988, the addition of an SFP cover with tamper-indicating seals, made it less likely that the segments could have been stolen or diverted.

4.

5.6 CONCLUSION

S

• Throughout the entire period of interest, HBPP maintained compliance with applicable NRC regulations designed to preclude theft or diversion.

• Review and analysis' of relevant HBPP documents produced no evidence that theft or diversion of the fuel rod segments occurred.

• In 2004 and 2005, the SNMP team interviewed numerous current and past plant e miployees and contractors. None, of the individuals interviewed believed that theft of the'fuel rod segments was possible, and no interviewee provided any evidence even suggesting that theft or diversion occurred. Additionally, interview results showed that very few individuals actually even knew of the existence of these three fuel rod segments.

• During the' 1968-1974 time periods, when the SFP was uncovered and there'was no formal security force at HBPP, theft of unshielded fuel rod segments would have presented a significant health risk by radiation exposure.

• Theft using a shielded cask would have required the knowledge of a larger number of plant employees. The need to open the RFB to allow access of the shielded cask, using the plant crane to support the moving of the cask into the pool, and the required work in the SFP would all have been observed by plant employees (i.e., operations, radiation protection, and, after 1974,'security personnel).

• The fuel rod segments have virtually no economic or strategic value.

Successful theft or diversion of the fuel rod segments would present challenges that are technically complex, risky, life threatening, and expensive. Moreover, the fuel rod segments are of insufficient quality and quantity to construct an effective radiological dispersal device or a nuclear weapon and are substantially sub-critical.

• No groups or individuals have claimed to have stolen or diverted the fuel rod segments over the entire periods of interest.

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4.6 IMPLAUSIBLE SCENARIO - OTHER DIRECT SHIPMENTS AND LOW-LEVEL RADIOACTIVE WASTE SHIPMENTS,,

As previously'discussed, the investigative process led the Project team to consider a wide variety of potential scenarios associated with low-level radioactive waste (LLRW) shipments and other direct shipments (ODS). Many of these shipments had no basis for further c6nsideration based primarily either on the type of packaging utilized for the shipment or the final destination of the shipment. Nevertheless, to ensure consideration of even these most unlikely shipments, the team analyzed their plausibility utilizing a set of evaluation criteria.

The following table summarizes the'criteria that were followed in assessing the LLRW shipments and ODS.

EVALUATION CRITERIA -'LLRW SHIPMENT & ODS IMPLAUSIBLE SCENARIOS Issue Criteria Result Packaging &

iScreening Tool - Radiation Levels Above Screening Tool Radiation Level Radiation Level based on type of package (i.e., box, Threshold - Further Consideration drum, barrel, etc.)Beo Below Screening Tool Radiation Level (Used for non-shielded packaging /

Threshold -'Screen-Out containers, not applicable for shielded casks)

Shielded Cask Yes or No Yes - Further Consideration No - Screen-Out Source Initially from the'Spent Fuel Pool -

Yes - Further Consideration Location YesorNo No - Screen-Out Destination ODS or'LLRW Facility ODS - Screen-Out (w/exceptions)

.LLRW Facility - Further Consideration Manifested Similar appearance and/or Yes - Further Consideration Contents configuration of fuel rod segments and/or canister, hidden or masked -

No - Screen-Out Yes or No Process Solidification of Ion exchange resin Yes - Screen-Out or concentrated liquid - Yes or No No - Further Consideration a

i The team utilized the criteria to examine and evaluate whether the fuel rod segments and/or the pipe containericould have been removed from the HBPP site in something 'other than'r a'sie1lded cask and shipped to'either a LLRW facility.(i.e., Bamwell, Hanford) as low specific activity (LSA) waste' or as an ODS 4-29

I~LA_

to a licensed end-user facility (i.e., GE-Vallecitos, a utility, 'etc.) for their utilization. The team confirmed that the identified LLRW shipments and ODS could not have contained the fuel rod segments and/or the pipe container without detection.

This discussion is not intended to'provide a complete discussion of the evaluation process thatwas utilized, but rather a basic understanding of the scope, objectivity, and level of effort expended to assess even the most unlikely LLRW shipment and ODS scenarios.4 4.7 A-49 SEGMENTS IN AN ALTERED CONFIGURATION Based on the fact that the Project has not found evidence that the A-49 fuel rod segments were inadvertently removed from the SFP and shipped to a LLRW facility, it can reasonably be concluded that the subject segments are still in the SFP. Inspection of the SFP has resulted in the identification and collection of numerous fuel rod fragments.

It is possible that some of the fuel fragments in the SFP are the unaccounted for fuel rod segments in a configuration that was altered from that immediately following the 1968 cutting 'operation of A-49.5 Based on internal evaluations and a consultant's study, the Project team has concluded that it is possible that fragments from the three 18-inch segments, along with the remnants from the cut A-49 rod, may be among the fuel fragments in the SFP.

There are many notable facts that bear on the question of whether the segments and/or remnants of the A-49 fuel rod are to be found among the fuel fragments remaining in the SFP,

• At the time that HBPP Unit 3 entered commercial service in 1963, its nuclear fuel Type.1 assemblies utilized stainless steel as the fuel rod cladding. The stainless steel clad fuel experienced gross failures of its cladding. These failures resulted in cracking and stress failures of portions of fuel rod cladding that in turn resulted in fuel fragments being created.

Photos taken with a Polaroid camera during fuel inspections conducted in 1966 of the A-49 rod prior to its being cut reveal that the'rod in question was a failed fuel rod (see photo below - A-49 Tube I side B section 1II 9/7/66).

4Final Report - Screening Tool for Fuel Rod Segments in Offsite Shipments, SNMP Report 5 The three fuel rod segments were cut from a failed fuel rod. It is unknown what physically transpired with the three segments after they were placed inside the pipe container and placed in the SFP in September of 1968. Assuming the segments were separated from the pipe container, either intentionally or otherwise, it has been hypothesized that the three segments from the damaged fuel rod could have undergone alteration in their size and condition by being placed in the SFP storage container for fragments which subsequently had other material placed on top of the fragments; from being subjected to heavy loads (in or out of the pipe container) from casks being placed in the SFP, etc.

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• The practice at HBPP during the time period that fuel failures were occurring (1 965-1968) was to capture the fuel fragments and place them in a storage container in the SFP.

• Documentation has been reviewed that indicates it was the intent to ship the SFP fragment storage container (aluminum channel made in the shape and size to fit into a failed fuel can) for reprocessing.

• Fuel inspection records for both stainless steel and zircaloy-clad fuel assemblies confirm that in the HBPP zircaloy-clad fuel rods were not subject to the gross cladding failures experienced with stainless steel-clad fuel.

HBPP began exclusively using zirdaloy-clad fuel in July, 1969 mitigating gross cladding failures and concomitant generation of fuel fragments.

• All of the stainless-clad fuel assemblies were shipped for reprocessing beginning in mid-1969 and ending in 1971.

• 'There is no evidence indicating that any other Type 1 stainless-clad fuel rod, other than A-49, was ever mechanically cut at HBPP Unit 3.

• The cut segments were placed in a 1-1/2 inch diameter schedule 40 steel pipe with a welded cap on one end and a threaded cap on the other. The threaded cap had a removablelifting bail attached. The interior of the pipe container was approximately 19 inches in length. The total length of the container, including the exterior end caps was approximately 23 inches. The pipe container with the bail is estimated to have weighed about 6 pounds, making the total weight of the pipe container with the three fuel rod segments about 10 pounds.

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HilL.

• The procedure for cutting the rod from assembly A-49 titled, "Procedure for Cutting Fuel Rod for Battelle Shipping Study" step G reads in part, "Attempt to remove the part of rod still in the element. If it comes out,'transfer it to the garbage can." Also, On Site Review Committee meeting minutes, dated October 2, 1968, state in pertinent part that: "[t]he unused portion of rod was placed in the 'garbage can' in the pool..."

• The last official record specifying the location of the pipe container with the three fuel rod segments is a Special Work Permit (SWP) dated September 27, 1968, which states that the container was removed from a shielded cask and stored in the SFP.

• Project interviews include a former HBPP engineer's recollection that a lanyard was attached to the container and to the railing on the SFP with a caution tag indicating the fuel rod segments were enclosed in the container.

• The documentary evidence regarding the disposition of either the pipe container or the three fuel rod segments subsequent to the September 27, 1968, SWP either was not found or does not exist.

• Neither the pipe container nor the intact three 18-inch fuel rod segments have been located after extensive and thorough searches of the SFP.

There is no evidence that either the pipe container or the intact three 18-inch fuel rod segments were shipped to a LLRW facility or otherwise shipped from HBPP.

• There is no evidence that either the pipe container or the intact three 18-inch fuel rod segments were shipped to the reprocessing facility in West Valley, New York.

During Phase 1 of the search for the A-49 fuel rod segments, PG&E utilized the services of two In-Service Inspection (ISI) Specialists from Diablo Canyon Power Plant (DCPP) to assist in determining whether the'fuel fragments that were being viewed at that time were possibly cut pieces from the A-49 fuel rod. Based on videos that were observed during mid-August 2004 an ISI metallurgist/specialist concluded that:

"After observing the latest video footage of the fuel fragments identified as

'A' through 'L,' I still do not believe the. cut pieces from the A-49 assembly are among them. I also observed the videos of the three apparently stainless steel fuel fragments found in the UD-6N box. These pieces are temporarily identified as a 56" end piece, a 30" end piece and a 14" piece.

None of these pieces have cut ends. -Both end pieces have a fractured end opposite the end pin. The 14" piece has fractures on both ends and two additional circumferential fractures near one end. This piece is also bent into a partial hook shape on the end with the two additional cracks.

I also observed all the available video footage of the other fuel fragments in buckets and possible fragments in the bottom of some of the spent fuel 4-32

cells. None of the visible ends of these fragments appear to be cut ends.

Some of the ends of these fragments are either not visible or are not clear enough to make a determination in the existing videos."

In late August, after more video information was available the metallurgist/specialist concluded in pertinent part:

"After observing the videos of the fuel fragments found thus far I do not believe the saw cut segments from the A-49 assembly are among them. None of the ends of the cladding that contained fuel appear to be saw cut. All exhibit the appearance of a fracture surface and are dark in color as if oxidized to some degree. This appearance is more typical of intergranular stress corrosion cracks that occurred at operating temperature."

The ISI specialist went on to state'the basis for his conclusion:

"This conclusion is based on the existing videos I observed on August 28 and 29.

My hope is that the three essentially' 18" pieces will be found. I believe that they will be identifiable by some obvious saw cut ends as well as the relative uniformity of length. I believe the saw cuts may be relatively clean and free of heavy oxidation. Some of the file marks 'described in the procedure for cutting the fuel rod may also be visible'."

In September 2004, subsequent to the 'efforts of the 1S1 specialists, DVDs of the fuel fragments were being'shown to'a retired GE fuels expert who stated that he believed a number of the fragments he was observing in the videos appeared to have been mechanically cut..

In an effort to resolve this differing professional o inion 'surrounding the fuel fragments, PG&E contracted with ATI Consulting to review digital video and still photographs of the fuel fragments'to determine their potential to be cut and, subsequently, the possibility of the fuel fragments being a portion of the fuel rod from Assembly A-49.

ATI Consulting-enlisted the assistance of a technical consultant and, on the advice of that consultant, the professional services of ANATECH Corporation (a company experienced with nuclear fuel issues).

It should be noted that additional fragments were being identified, evaluated, measured, and inventoried with detailed close-up video documentation during September and October, 2004 after the ISI specialists performed their evaluation.

For example, fuel fragment number 13 (FF#13) was video taped on October 1, 2004, shortly after ATI Consulting had been retained and had examined other fragment video.' FF#13 appears to show clear evidence of a mechanical cut (with subsequent concurrence from the ISI specialist).

6 ATI Consulting is a privately held corporation that the Project Manger for this Project had an ownership interest during the period from 1991 to 1994.

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1.

Fuel Fragment #13 Fuel Fragment # 13 The ATI Consulting team established a basis for the assessment of the fuel rod segments. That basis was a set of complementary criteria'developed for distinguishing between ends of broken segments produced by cutting, as opposed to ends of broken segments produced by other failure mechanisms, such as intergranular stress corrosion cracking, circumferential cracking or tearing. The set consisted of five criteria:

4-34

(1) planarity/perpendicularity of the end surfaces of the individual fuel rod fragments, relative to their axial orientation; (2) appearance of the separated surfaces of the cladding, when viewed normal to the separated surface; (3) flushness of the separated surfaces of the fuel pellets with the separated surfaces of the cladding; (4) appearance of the separated surfaces of the fuel pellets,-when viewed normal to the separated surface; and (5) degree of associated intergranular stress corrosion cracking adjacent to the separated surface.

The ATI report concluded that:

• . there is reasonable evidence consistent with the proposition that fragments from the three 18-inch segments along with the remnants cut from the A-49 fuel rod may be amongst the fuel fragments in the HBPP spent fuel pool." 7 The IS specialist was asked to review the AT[ report and its conclusions. The following is his response:

"I have reviewed the report and I don't have any concerns or issues with it."

Conclusion The Project Team concludes that it is uReasonably Possible" that the three 18-inch fuel rod segments remain in the SFP in an altered condition. There is reasonable evidence that there are cut fragments remaining in the SFP. Despite the fact that neither the intact 18-inch rod segments nor the pipe container have been located in the SFP, there is no evidence that either was shipped from HBPP.

7 ATI Consulting Report, Evaluation of Nuclear Fuel Rod Fragments and Inference to Fuel Rod A-49 at Humboldt Bay Power Plant, March 31, 2005.

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5.0 CONCLUSION

S 5.1 PROBABILITY RANKING The investigative process'led the Special Nuclear Material (SNM) Inventory, Inspection and Control Project (Project) team to consider a wide variety of potential scenarios for the disposition of the three'1 8-inch A-49 fuel rod.

segments. The first goal was to determine whether the scenarios were plausible or implausible. For those scenarios deemed plausible (i.e., possible), a written disposition of each scenario was prepared that included a description of the scenario; investigation, analysis, and conclusions. The investigation produced no clear and convincing evidence as to the Specific location of the three fuel rod segments. However, the Project team did assign one of four possibility:

categories'to scenarios:

• 'Highly Unlikely" means the event is very improbable.

"Possible, But Not Likely" means the event, while possible, would have a fairly low probability of occurrence.

• "Reasonably Possible" means the event may have occurred.

• 'Confirmed" means the event did occur.

The following discussion sets forth the Project's conclusions as to the likelihood of scenarios considered.

Implausible The Project team considered a wide variety of potential scenarios associated with low-level radioactive waste (LLRW) shipments and other direct shipments' (ODS). Many of these shipments had no basis for further consideration based primarily either'on the type of backaging utilized for the shipment or the final destination of the' shipment. Nevertheless, to ensure consideration of even these most unlikely shipments, the team analyzed their plausibility utilizing 'a set of evaluation rcriteria.The team confirmed that the identified LLRW shipments and ODS, with the exception of 9 LLRW'shipments'to Barnwell and Hanford and 15 shipments to Nuclear Fuel Services (NFS) for reprocessing,' could not have contained tie'Wfuel rod segments and/or the 'pipe container without detection. All LLRW shipments made to'Beatty, Nevada,' screened out as implausible.

Highly Unlikely Three alternatives'of theft or diversion of the'fuel rod segments were considered by the Project: theft by an external entity, theft by an insider, and unauthorized

'-1

disposal. The investigations and analyses support the conclusion by the Project team that the theft or diversion scenario is "Highly Unlikely."

The inspection of spent fuel pool (SFP) locations and the examination of SFP items was comprehensive, targeting those locations and items within the pool that were the most likely storage locations for the fuel rod segments or the pipe container. The results of these inspections established that, subject to the limitations of each search, the intact fuel rod segments and/or the pipe container.

are not in locations searched. But given the limitations and conditions in Section 4.1, the inspections and examinations cannot rule out the possibility that the fuel rod segments remain in the SFP in either an uninspected location, an unexamined item, or as part of the fuel fragments that were found; It is the Project's conclusion that it is "Highly Unlikely" however that the intact fuel rod segments or the pipe container with the fuel rod segments within it will be found in the SFP now or at the time of decommissioning The inspections for locations outside the SFP in Unit 3 or in the vicinity of Unit 3 did not result in the discovery of the fuel rod segments or the pipe container, fuel fragments, or any other SNM. Inspection of several areas of interest, namely the access shaft pipe chase, the reactor vessel, the drywell, and the fuel transfer cask was impractical at this time. Based on available information, it is believed to be "Highly Unlikely" that the fuel rod segments, pipe container or fuel fragments are in any of these locations but this cannot be absolutely verified until removal of these components during decommissioning.

Possible, But Not Likely It is plausible that an opportunity for the inadvertent shipment of the rod segments and/or the pipe container existed in shipments from the SFP because workers who may have been unfamiliar with materials and items in the SFP, or had to deal with visibility issues in the SFP may have inadvertently loaded the fuel rod segments and/or the pipe container in an LLRW shipment. However, there is no evidence that the fuel rod segments and/or the pipe container were shipped to either the Barnwell or Hanford LLRW facilities., An opportunity for the inadvertent shipment of either the fuel rod segments or the pipe container existed to some small degree in each of three 1983 and one 1985 Barnwell shipments and also in five 1986 Hanford shipments. These shipments, were made as part of several SFP clean-up campaigns conducted at Humboldt Bay Power Plant (HBPP). The likelihood of an inadvertent loading of the fuel rod segments or pipe container is, therefore, "Possible, But Not Likely" for the Barnwell and Hanford LLRW facilities.

Of the ODS shipments made by HBPP, only the 15 spent fuel shipments to NFS for reprocessing are considered as plausible candidates for having contained the fuel rod segments. The conclusion statement concerning shipments to NFS for reprocessing is made based upon the investigative results of this scenario 5-2

disposition that include facts, circumstantial evidence, supposition, and postulated events that support the plausibility of this scenario. Other than the possibly incomplete record that indicated shipment of the A-49 assembly to NFS, there is no documentary evidence indicating that the fuel rod segments were shipped to NFS for reprocessing. However, interviews of employees who worked at HBPP Unit 3 in the 1960s and subsequent years provided speculative evidence that the three fuel rod segments went to NFS (i.e., they "believed" that the A-49 fuel rod segments may have been shipped for reprocessing). An opportunity for the'inadvertent, or even intentional, shipment of the fuel rod segments existed to some degree in each of the 15 spent fuel assembly, shipments to NFS between 1969 and 1971. The Project team concludes that it is "Possible, But Not Likely," that the three A-49 fuel rod segments were shipped to NFS for reprocessing.

Reasonably Possible The Project team considered the four LLRW shipments to Barnwell and the five to Hanford concomitant with the possible shipment of the fuel rod segments to NFS for reprocessing. When considered concomitantly, it becomes "Reasonably Possible" the pipe container last known to have contained the three fuel rod segments, or the fuel rod segments themselves, could have been shipped to either Hanford, Barnwell, or to the NFS West Valley reprocessing facility. This is not to say that it was considered reasonably possible that the three fuel rod segments were sent to Hanford, Bamwell, or NFS when considered individually.

However, when considered in the aggregate, coupled with the fact that the pipe container the segments were originally in has not been found in the SFP and no record identifying what happened to the pipe container has been located subsequent to September 1968, it is the judgment of the Project team that the possibility of the segments having been shipped to Barnwell, Hanford or NFS increases from 'Possible, But Not Likely" to "Reasonably Possible."

Despite the fact that neither the intact fuel rod segments nor, the pipe container they were originally stored in have been located in the SFP, there is no evidence that either was shipped from HBPP. ' There is however, reasonable, but not.

conclusive, evidence that the ProjectfTeam has found sufficient stainless steel-clad fuel fragments that exhibit mechanical cut characteristics to.suggest that the segments in broken form and the remnants of the cut A-49 rod were found in the central storage container of the SFP.; This is the location that HBPP personnel would by general practice most likely have placed the segments in if they were removed from the pipe containerqand stored in the SFP. The Project team.

concludes that it is 'Reasonably Possible" that the three 1 8-inch A-49 fuel rod segments remain in the SFPin an altered condition under PG&E's physical,.

control as fuel fragments rather than fuel rod segments.-

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Confirmed No scenarios were confirmed as having occurred.

5.2 HEALTH AND SAFETY The results of the investigation into' the three unaccounted for fuel rod segments were inconclusive with regard to their final disposition. The investigation concluded that theft or diversion was highly unlikely and therefore an analysis for health and safety for that scenario was not undertaken (see Section 4.5 of this Final Report). The Project did conclude however, that the following possibilities exist for the fuel rod segments:

• They are still in the SFP, or

• They were shipped to NFS in West Valley, New York, for reprocessing or they were shipped to Barnwell and/or Hanford LLRW facilities.

The SFP and the areas outside the SPF at HBPP were thoroughly searched and the intact three fuel rod segments were not found. However,-until all fuel is removed and the SFP and certain areas outside the SFP are dismantled, it cannot be said with complete certainty that the intact fuel segments are not there even though the Project believes such a possibility is "Highly Unlikely" (see Sections 4.1 and 4.2 of this Final Report). The Project also-concluded, however, that it is "Reasonably Possible" the three fuel rod segments remain in the SFP in an altered configuration (see Section 4.7 of this Final Report). If the fuel rod segments are in the SFP, they are in a safe location and there is no increased risk to the health and safety of the public, workers, or environment.

Though no records were found to support the hypothesis, the fuel rod segments may have been added to the shipping cask with its parent assembly when the parent assembly was shipped to NFS in 1969 or with other shipments of Type.1 fuel between 1969 and 1971 (see Section 4.4 of this Final Report). If the fuel rod segments were shipped to NFS, the shipping and processing was in accordance with approved methods and there was no increased risk to the health and safety of the public, workers, or environment.

Though the investigation was able to exclude Beatty, the investigation was unable to exclude the Barnwell and Hanford LLRW facilities as possible disposition locations for the three fuel rod segments. Barnwell and Hanford are not licensed to accept SNM in the form of fuel (see Section 4.3 of this Final Report). Therefore, it is necessary to consider the potential health and safety effects, if any, of the various LLRW shipments and potentially disposed fuel rod segments (SNM Project Safety Analysis Report, "Public Health & Safety HBPP Unit 3 A-49 Fuel Rod Segments").

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The HBPP radioactive wastes shipped to'either of the LLRW facilities at Barnwell and Hanford are packaged in containers known as liners which are transported in specially designed and licensed transportation casks. The wastes from HBPP were surveyed before packaging, after packaging in the liner, and after--

placement of the'linerinr the trahnsportatio'n'cask and before departure from HBPP. This was done to ensure that the transportation cask radiation levels meet federal Department of Transportation, NRC, various state, and LLRW facility standards designed to ensure the protection of public health and safety during shipment to and disposal at the LLRW facilities. The radiation levels of the three fuel rod segments, if packaged aind shipped under the-required standards, would be well below those radiation safety thresholds. If shipped,"the radiation levels of the fuel rod segments would have been lower than the radiation level of some of the other irradiated and radioactive materials authorized to be included in the various HBPP shipments to the LLRW facilities.

If shipped offsite, the fuel rod segments were-shipped in an otherwise compliant LLRW shipment to either Barnwell or Hanford. The shipment did not pose 'a significantly increased risk to'the health and safety of the public, the workers, or the environment. The transport containers and casks and survey programs described above'provided sufficient protection for transport operators and members of the general public during transport from HBPP to the LLRW disposal facilities.

Arriving at the LLRW facilities, the transportation cask would be inspected by facility personnel and accompanying documentation would by checked with regard to its meeting the facility's license requirements. Upon completion of the inspections and documentation review, the liners would be'removed from the transportation cask, quickly.deposited in burial trenches,' and covered with earth to shield the workers and'public from radiation.

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4-The disposition -of the fuel rod segments' by burial at either of the LLRW facilities would not increase the risk to the health and safety of the public, site workers, or the environment. Both of the LLRW facilities are designed'and licensed to safely' dispose of all radionuclides contained in the three fuel rod segments'.': Indeed, all of the radionuclides contained in the three'fuel rod segments'are already present in the inventories of those facilities. Also, the current radionuclide inventories at the subject facilities' far excee'd thbafrount of radionuclides fcor'tained in the fuel:

rod segments.' Thus, even if ship" ed, the presence of the fuel rod segments would add only a very small amount to the pres6nt radionuclide' inventories at the LLRW facilities.

Furthermore, the two-Millstone fu6l rods that were also possibly disposed of at either the Barnwell or Hanford LLRW facilities contained considerably larger inventory of radionculides than the three HBPP fuel rod segments. The following Their licenses, however, require that transuranics radionuclides be evenly distributed within a homogeneous waste form and are incidental to the total activity.

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table provides a comparison of the HBPP fuel rod segments, Millstone fuel rods, and the Barnwell and Hanford LLRW radiological inventories.

RADIOLOGICAL INVENTORY COMPARISON Radionuclide HBPP Three Fuel Millstone Two Barnwell Hanford Rod Segments @ 40 Fuel Rods Circa Circa (2000)

Circa (2000)

Year Decay (2005)

(2000)

Total Uranium 1126.6 8210 5,830,000,000 27,518.181 (gm)

(reported as pounds depleted uranium, 1965 1980) 23$u (gm) 16.59 132 3,200,000 (reported 101,915 as total fissile material) 2"Pu (gm) 4.56 27 212 25,060 (reported as 1291 (Ci) 0.00001389 0.0001 9.1 5.63 "Tc (Ci) 0.00654 0.032 88.75 50.1 Total 79.5 518 7,100.000 1.655,100 Radioactivity Inventory (Ci)

Even though neither the Barnwell nor Hanford, LLRW facilities are licensed to accept spent nuclear fuel, the addition of the three 18-inch fuel rod segments should not cause either facility to have radionuclides that would change the LLRW site's performance assessment for continued long-term disposal and renewal of the facility's license. For this reason, the LLRW facilities' environmental, radiological, and safety programs, which assure the safety of the long-term disposal of the radioactive materials, would be adequate to account for the relatively small amounts of radioactive material in the three fuel rod segments if they are present at one of these LLRW sites.

In December 2002, in their Draft Safety Analysis of the long-term hazards of the Millstone fuel rods potentially disposed of at either the Barnwell or Hanford LLRW facilities, the NRC concluded that:

• the conclusion, from these analyses, is that the overall risk form the fuel rods, if they are at Bamwell (Hanford), is minimal to both the present workers and future generations of the public.

• low probability inadvertent intruder scenario analyses resulted in potential doses not only well below the 5-mSv/y (500-mrem/y) dose value used for inadvertent intruder analyses but also 5-6

..below the regular part 61's 0.25-mSv/y (25-mrem/y) public dose limit releases of radioactive material (10 CFR 61.41).

• based on the very low risk that the fuel rods pose, 'if they are -at Bamwell (Hanford), retrieval of the rods would not be justified by arguments concerning imblic health and safety.'

Since the HBPP fuel rod segments radiological inventory only'represents' approximately 15 percent of the Millstone fuel rods' inventory, it can be logically concluded that the NRC Safety Analyse's performed for Barnwell and Hanford would be appropriate for and bound thb'HBPP segments with -regard to the -

issues of public health and safety.2 The Bamhwell and Hanford LLRW facilities' operations and'programs are also subject to extensive state' regulatory oversight, independent assessments, and periodic inspections that provide further assurance of ongoing health,-safety, and environmental protection. Moreover, none of the numerous assessments and inspections at either fcility~has rev.eal6d a ny'e'nvironmental or other health and' safety problems that could be attributable"to the possible disposition and burial of the three fuel rod segments ateither Barnwell or Hanford.- The NRC also provides additional 'oversight by conducting independent program~evaluations of the States' overall regulatory programs and the Low-Level Waste Programs for both the States of South Carolina and'Washington, respe6tively.

If the three fuel rod segments are buried at either Barnwell or Hanford:

• The rod segments would not introduce any new radionuclides to the radioactive inventory of the Barnwell or Hanford facilities.

• The inventory of radioactive materials in the fuel rod segments would not add significantly to the inventory of the Barnwell or Hanford facilities.

• Barnwell and Hanford have programs and plans in place to continue monitoring waste during operations, after closure, and through the institutional control period as defined for each of the facilities.

2 Section 3.1.1 of this report discusses the one complete and three partial incore detectors that are not present in the HBPP SFP, although records indicate the detectors remain onsite. The SNM inventory for the one complete and three partial incore detectors is less than one tenth of a gram. This would represent a negligible addition to the radionuclide Inventories already present at either facility. Further, shipment of incore detectors to these two facilities was permitted under their respective site licenses. For this reason, the inadvertent disposal of the one complete and three partial incore detectors at Barnwell and/or Hanford would not adversely impact the public health and safety.

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L-

• The disposal of the three fuel rod segments would have no impact on an inadvertent intruder'not already accommodated by plans and programs already fully in place at both Bamwell and Hanford.

• Continuing regulatory oversight, facility plans and financial resources provide for continued monitoring, maintenance, and corrective measures should they be needed.

• There would be no criticality risk associated with the three fuel rod segments, either by themselves or in tandem with other objects (including the Millstone fuel rods) that may be proximate to the segments.

• Exhumation of the three spent fuel rodsegments would pose a far greater worker health and safety risk and potential environmental detriment than leaving them buried at either Barnwell or Hanford.

It can be concluded that the possible disposal of the three HBPP fuel rod segments at either the Barnwell and/or Hanford LLRW facilities would have no impact on the health and safety of the public and workers, the operation and closure of the subject LLRW facilities, the environment, and the various inadvertent intruder scenarios (SNM Project Safety Analysis Report, "Public Health & Safety HBPP Unit 3 A-49 Fuel Rod Segments").

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6.0 CAUSE ANALYSIS AND CORRECTIVE ACTIONS This cause analysis addresses inadequate control and accountability of special nuclear' material (SNM) at Humboldt Bay Power Plant'(HBPP) that resulted in inaccurate SNM inventories, inaccurate material status reports, unaccounted for A-49 fuel rod segments,,

and missing ion chambers.

Included is a statement of the problem-;a discussion of relevant backgrourad information;,

a chronological description of events and'co'nditions; a description of consequences, causes, and barriers; and recommended corrective actions.

6.1

SUMMARY

SNM accountability first became inadequate in 1965 when fuel fragments: were separated from their parent assemblies and were collected and stored in a separate container in the spent fuel pool (SFP) with no procedural controls. Subsequently, three fuel rod segments2, one complete incore ion chamber 3, and three 'partial incore ion chambers that were all originally st6red -in the SFP and now declared missing, were not, by today's standards,'properly controlled and accounted for.

SNM inventories first became inaccurate in 1969 when fuel assemblies shipped offsite for reprocessing were missing those fuel fragments that remained in the SFP. From that time forward, inaccurate material 'statu6 reports were submitted to the Atomic Energy Commission/Nuclear Materials Management and Safeguards System/Nuclear Regulatory-Commission (AEC/NMMSS/NRC). SNM inventories and material status reports were also 'affected by' the failur'e 'to 'properly account for the fuel rod segments cut from A-49 and, nearly two decades later, the one complete and three partial ion chambers.

The investigation of this problem was initiated in November 2003 when HBPP recognized that fuel fragments were not properly included in SNM inventories. In June 2004, three fuel rod segments were discovered missing, arid in February 2005, one complete and three partial incore ion chambers were discovered missing.

Numerous barriers were in place to prevent loss of control and accountability'of SNM at HBPP. However, some of these existing barriers were ineffective. Other barriers were missing that, had they'beeri in place; could have either helped prevent'the occurrence of the SNM control and accountability piroblem or allowed earlier'recognition and correction of the problem.' The ineffective barriers included SNM procedures,'SNM

' A fuel fragment is defined as a clad or unclad portion of a fuel rod, including pellets or portions of pellets that have a measurable dimension greater than % Inch. Cladding without fuel is irradiated hardware, not a fuel fragment. Thte'fuel in fuel fragments contains SNM.

2 Fuel rod segments are the three pieces of fuel rod, each approximately 18-inches in length, when cut from assembly A-49. The fuel in fuel segments contains SNM.

3 An assembly of three ion chambers is called an Incore string. The ion chamber contains SNM; the rest of the incore string is not SNM. 'An incore secti6n is a partial length of an incore string, which may or may.

not hold one or more ion chamber's.

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It.

Custodian training, SNM inventory practices, SNM inspections and audits, and management oversight. Missing barriers included regulatory/industry guidance development and maintenance of an 'inventory of record," and an inventory reconciliation process. Those barriers that remained effective during the course of events from 1965 to 2004 included the Radiation Protection Program, control of fuel assemblies, and physical security. The impact of the effective barriers greatly exceeded the impact of the ineffective and missing barriers as they protected public and worker health and safety, controlled and accounted for all but a very small amount of SNM, and protected against unauthorized removal of SNM from the HBPP site.

For the fuel fragments, the causes were determined to be:

1. Plant management did not require development of procedures for control and accountability of fuel fragments.

2. Plant culture in the 1960s and early 1970s encouraged individual problem solving, rather than development and use of procedures for noncomplex evolutions. This approach resulted in activities that were either performed without procedures, or with procedures that would be considered inadequate by current standards.

3. The SNM custodians were not adequately trained on control and accountability of SNM.

4. There was no specific regulatory guidance for the control and accountability of fuel fragments4.

5. There was no specific industry experience or standards for control and accountability of fuel fragments.

For the missing fuel rod segments, the causes were determined to be:

1. Plant management did not require development of procedures for control and accountability of fuel rod segments.

2. Plant culture in the 1960s and early 1970s encouraged individual problem solving, rather than development and use of procedures for noncomplex evolutions. This approach. resulted in activities that were either performed without procedures, or with procedures that would be considered inadequate by current standards.

3. The SNM Custodians were not adequately trained on control and accountability of SNM.

4 Compliance-based inspections and audits performed by both PG&E and the AEC with full knowledge of the existence of fuel fragments did not raise control and accountability issues and thus reinforced accountability at the fuel assembly, not fragment, level.

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4. There was no specific regulatory guidance'for the control and accountability of fuel rod segments.

5. There was no specific industry experience or standards for the control and accountability of fuel rod segmerits.'

For the missing incore ion chambers, the causes were determined to be:

1. An inadequate procedure was'us'ed to determine the location of ion chambers' in incore strings during cutting operations.

2. The SNM Custodians were not adequately trained on control and accountability of SNM.

3. A personnel error - cognitive, for failure to follow the SNM control and accountability procedure for inciore ion chambers.'

Pacific Gas and Electric Company (PG&E) believes the problem with loss of SNM control and accountability would have been discovered sooner if SNM Custodians had been 'adeqdately trained on' the control, 'a~ctc'nta'bility, and inventory of SNM; if the SNM procedures had addressed fuel fragments, fuel rod segments, and the creation of records to track fragments or segments; and if the HBPP accounting practices'had' required comparison of the physical inventory with a definitive "inventory of record."

Following completion of the'SNM Inventory, Inspection, and Control Project (Project) and development of the causes contained in this Cause Analysis Report, the Technical Review Group (TRG) for Nonconformance Report (NCR) HB3-04-QC-N005 discussed and agreed on the following corrective actions:

Immediate Corrective Actions (ICAs)

ICA 1: HBPP procedures have been revised to require specific detail(s) regarding the documentation of location of fuel components as they are identified in the 'SFP. A full cataloging and characterization of the contents was performed to ensure a complete and accurate accounting of all SNM in PG&E's possession at HBPP, down to the fragment level (This ICA also became CorrectiveActions to Prevent Recurrence (CAPR) 3).

ICA 2: Prepare'draft revisions to SNM ep6orting forms 741, 742, and 859 based on the results of a formal PG&E calculation prepared to reverify the'SNM inventory as reported to NMMSS/NRC in October 2003. The calculation used a technique developed to convert'rmeasured quantities of fuel frag'ments to mass of SNM.' The assumptions used in the conversion were'documented inrthe6 SNM inventory.

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., I ICA 3: Developed procedures that will measure and quantify SNM waste and fuel fragments. These"procedures will result in corrections to the SNM inventory that will constitute an acceptable long-term corrective action (This ICA also became CAPR 1).

Corrective Actions to Prevent Recurrence (CAPRs)

CAPR 1: Develop procedures that will measure and quantify SNM waste and fuel fragments. These procedures will result in corrections to the SNM inventory that will constitute an acceptable long-term corrective action (see ICA 3).

CAPR 2: Complete a detailed SNM inventory based on results of the ongoing SFP work.

CAPR 3: Revise HBPP procedures to require specific detail(s) regarding the documentation of location of fuel components as they are identified in the SFP. A full cataloging and characterization' of the contents should be performed to ensure a complete and accurate accounting of all SNM in PG&E's possession at HBPP, down to the fragment level. (see ICA 1)

CAPR 4: Revise HBAP D-7 "Control and Accountability of Special Nuclear Material and Waste Shipments" and STP 3.6.6 "Annual Special Nuclear Materials Physical Inventory and Spent Fuel Pool Cover Seal Verification" to address the issue of the physical inventory of non-fuel SNM in the pool.

CAPR 5: Revise procedures EDOI B-3, "Movement of Non-Fuel, Material in Spent Fuel Pool," B-5, 'Fuel Handling Procedure for Moving Fuel Within the Spent Fuel Storage' Pool," and HBAP D-7, "Control'and Accountability of Special Nuclear Material and Waste Shipment" to ensure that procedures used for future work in the SFP and other areas where SNM may be located shall include provisions for control and accountability of fuel fragments and non-fuel SNM.

CAPR 6: Create a "qualification" for the SNM Custodian and persons designated to be SNM Custodian.

6.2 PROBLEM STATEMENT The problem considered in this cause analysis for HBPP Unit 3 is inadequate control and accountability of SNM that resulted in inaccurate SNM inventories at HBPP, submittal of inaccurate material status reports to the AEC/NMMSS/NRC, missing fuel rod segments, and missing ion chambers.

The SNM accountability process first became inadequate in' 1965 when fuel failures during operation resulted in fuel fragments that were separated from their parent fuel assemblies when the assemblies were inspected and cleaned in the SFP following discharge from the reactor in the period 1 965-1967. While there was informal guidance provided and a routine practice established to collect and store fuel fragments in a 6-4

container in the SFP, there were no procedural controls to account for the SNM content or for the number, size, or exact location of these fragments.

An additional issue regarding the possibility of pellets being picked up during vacuum cleaning of the SFP and loose pellets berig placed in'vacuum bag (circa 1976 during a pool cleanup) has been evaluated. These records are vague and no subsequent records were located. Therefore, for purposes of this cause analysis, such pellets, if they in fact exist, are considered to be a' part of the fragments stored in SEP containers, and are not considered further in this report.

SNM accountability was also the issue for the three 18-inch fuel rod segments cut from assembly A-49 and stored in a container hung on the side of the SFP on September 27, 1968. Investigation determined 'there are no records of the movement or disposition of these fuel rod segments after September 27, 1968.

Finally, SNM accountability isalso the issiue for incore ion chambers. One complete and three partial ion chambers were declared missing on February 22, 2005. The ion chambers are believed to have been missing since 1985, when incore strings containing ion chambers were cut into sections for more efficient storage in the SFP and for shipment of the nondetector-containing sections to low level waste disposal sites.

SNM inventories became inaccurate after May 1969 when damaged stainless steel fuel assemblies were first shipped to Nuclear Fuel Services (NFS) for reprocessing. When fuel assembly shipments were' made, the"mass of SNM for entire assemblies was subtracted from the SNM inventory, even though some fragments from these fuel assemblies remained in the SFP. The inaccurate SNM inventories subsequently caused inaccurate material status' reports to be submitted to the AEC/NMMSS/NRC in the period 1969-2003." Similarly, SNM inventories and material status reports were also affected by the failure to 'properly account for the missing fuel rod segments and ion chambers.

6.3 BACKGROUND

6.3.1 PLANT CULTURE:

The information in 'this section provides a-former employee's view of the culture at HBPP during the first few years of plant operation. The information was prepared in August 2004 following'anrinterview at HBPP and is presented verbatim below. The interviewee was a Power Production' Engineer at HBPP from 1961 to 1969 who later became the Senior Vice-President and General Manager of Nuclear Power Generation for PG&E, with extensive experience at PG&E's Diablo Canyon Power Plant through the 1990s.

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Working Environment The working environment at HBPP in the 1960s and early 1970s was substantially different than that in a modem-day, post-Three Mile Island (TMI) plant.

The plant was thought of more as a production facility" than as a "nuclear facility." It was part of the "Steam Generation" department.

The latter wasn't created until 1980, as one of the post-TMI 'ixes."

The staff was small, with most of the members coming from the Company's fossil plants, after receiving in-house training on nuclear technology The above factors led to a working environment which was pattemed after that in the fossil and hydroelectric plants.

• Only the most complex evolutions were proceduralized, and even when there were procedures, they were often thought of more as training material than as documents to be used in-hand and followed step-by-step during performance of work.

• In line with the "production" and small staff philosophies, individual workers were encouraged to show initiative and creatively find solutions and/or 'Work-arounds" when they encountered problems. In today's environment, such a situation would call for stopping, getting approval for a procedure change, and documenting the process. This should not be misconstrued to mean that workers were encouraged to violate established safety standards. Safety was given a high priority then, just as it is today. But workers were given more latitude to use theirjudgment and experience in the performance of their work.

(Interestingly, this led to a high degree of worker accountability - you made your own decisions and were responsible for them.)

These philosophies then led to a culture directed more toward "how can I solve my immediate problem in. a safe and efficient manner, so that I can keep the job going,"rather than '7 have to make sure everything is properly reviewed and documented so that my every action can be reconstructed 40 years from now."

Attitudes Regarding Fuel and Fuel Storage Fuel was looked at on an individual assembly basis. Because of very poor visibility in the reactor vessel, and to a lesser extent in the pool, we were very concemed about verifying that we had properly loaded assemblies in both the 6-6

vessel and the pool. We carefully inventoried both locations to make sure we knew where every assembly w-as located.

'In the early 6ycles, when we had gross cladding failures, fuel rods would occasionally disintegrate in the pool when the fuel bundle channel was removed for fuel inspection and/or disposal. I can't recall any attempt to try to' precisely identify or quantify any fuel fragments that may have fallen out, which 'would have been difficult under the circumstances. We attempted to catch ther 'in a '"ellet catcher"that was fabricated in ordeto prevent them from dispersing all over the pool. But our focus, in terms of inventory, was the bundles themselves, as best I recall. In those days, fuel storage was viewed as a short-term proposition. It was anticipated that we would be sending the fuel, and most likely any dislodged fragments, off-site for reprocessing after a few years cooling time.: Long-term storage accountability was therefore not as much'an issue, although 'we always accounted for each bundle 'in the poo. What we had to do, once off-site' shipments' commenced, was meet Mhe requirements for documenting what was

'shipped. Presumably, this would also be verified by the transporter and the reprocessor upon receipt.

In short, the view was less toward keeping records that could be viewed 4 decades later, than with getting the failed fuel out of the reactor vessel, keeping the pool tidy and serviceable (ii.e.;, we didn't wantjunk and fragments scattered about, but rather collected in receptaci6s like the '"garbage can"), and getting the stuff off-site 'at the earliest opportunity-all the'while keeping the plant 'on-line.

Conclusion

'Given the culture of fossil fuel "problem solvers" rather than "nuclear archivists," I can see where fragments in the pool could have been moved about within the pool without adequate documentation by today's standards. It is possible that people felt that when the fragments'are shipped off-site, then' they' will be accounted for. Until then, it could have been viewed as sufficient to'siniply

' consider them to be part of the unquantified material that was known to be in the pool. This type'of reasoning would not be acceptable today, but was closer to the culture of 40 years ago.

6.3.2 PROCEDURES HBPP procedures for the accountability and inventory of SNM were first issued in 1962 and revised periodically in subsequent years. 'A review of procedures from the 1960s,1 970s, and 1980s (Reference 'i) shows that there were no requirements for accountability of fuel fragments. ' The procedures specifically stated that fuel accountability was'on a fuel assermbly basis.- However,'an internal HBPP rnemo describing fuel accountability during fuel inspections, dated July 20, 1966 (Reference 2), and written by the Power Production Engineer previously quoted, did note thebneed to estimate as accurately'as possible the 6-7

.I

'In'L-total number of rods (or portions of rods) missing from fuel assemblies. The memo goes on to state that HBPP was required to account for all of the uranium that it possesses, and had to estimate as accurately as possible the amount of fuel which ends up in the pellet catcher (a part of the fuel assembly cleaning system). Although not specifically stated, it can be inferred that the need for this accounting was for regulatory purposes. The information in this memo did not get incorporated into HBPP plant procedures for SNM'accountability. However, it is unknown why mariagement in the 1960s did not incorporate the fnemo information into plant procedures, or if management was ever aware of the memo written by the then young Power Production Engineer. This failure to identify fragment accountability in procedures 'may have been because there were no specific regulatory or industry guidelines for accountability of fuel quantities less than that contained in an entire fuel assembly. Additionally, another internal memo describing the fuel inspection program for July 13 - 17, 1966 (Reference 3), describes placing fuel fragments collected from the SFP into a container (later called the garbage can and then the central storage container).

It is possible that fragment records may have been kept in the SNM accountability ledgers and control operator logs of the 1960s and early 1970s.

However, an exhaustive document search failed to locate these ledgers and logs.

The procedures for SNM accountability did, however, provide specific accountability requirements for non-fuel' SNM containing items, such as excore fission chambers, incore strings containing ion chambers, and startup sources.

6.3.3 INSPECTIONS, AUDITS, REGULATIONS, AND GUIDANCE Periodic AEC/NRC inspections and audits, as well as internal PG&E audits, of the SNM accountability and inventory process at HBPP did not identify any problems related to fuel fragments (Reference 4),.even though the AEC and PG&E personnel were aware of fuel fragments being present in the SFP (Reference 5). HBPP does not know why the inspectors and auditors did not identify SNM accountability and inventory inaccuracies related to fuel fragments, but does know the audits were compliance based and the auditors did not specifically look for shortcomings in procedures. This failure to identify a problem may also have been because there were no specific regulatory guidelines for accountability of fuel quantities less than that contained in an entire fuel assembly. It should be noted that industry guidance and practice was to account for SNM on a fuel assembly basis from the time AEC regulations were first promulgated requiring SNM accountability in early 1967. This 1967 regulation required, among other things, the licensee to uestablish 'and maintain written material control -and accounting procedures, which are sufficient to enable the licensee to account for the sp ecial nuclear material in his possession under license." Prior to issuance of this regulation, HBPP SNM procedures were written to comply with the SNM requirements contained in 10 CFR 70 issued in 1956 and the operating license issued in 1963.

6-8

In October 1974, ANSI Standard N15.8-1974 (Reference 6) was issued, which was endorsed by NRC Regulatory Guide (RG) 5.29 (Reference 7). The standard states in Section 6.1 that "the basic unit for control of nuclear material shall be the nuclear fuel assembly." Section 6.'1 also states that'"Nuclear'material

-.contained in fuel elements (defined asthe smallest structurally discrete part of a fuel asisenibly, such as a fuel rod or fuel pin), not part of an assembly, shall be separately identified on all material bontrol records." RG 5.29, Revision 1, endorsing ANSI N15.8-1974, wasiot issued until June 1975,-well after the time fuel fragments were produced, collected, and stored at HBPP5.' Therefore, PG&E believes that it may have'been reasonable given the early regulatory guidance and industry practices for plant personnel to not include fuel fragments in the SNM inventory. Certainly the practice followed was not unreasonable.

Similarly, it may also have been reasonable for AEC/NRC and PG&E inspectors and auditors to not identify prob!ems related to accountability of fuel fragments.

Although regulationsihave notsubstantively changed since 1967, current NRC expectations are for licensees to 'account for fuel fragments and any SNM less tharn'an assembly.in the SNM inventory.

6:3.4 FUEL FRAGMENTS AND FUEL SEGMENTS During the period May'1969 to Jurne'1971, all of the stainless steel fuel assemblies were shipped from the HBPP SFP to NFS in West Valley, New York, for reprocessing. Each shipping cask held up to 18 fuel assemblies. When shipments were made, the total 'nUmber of fuel assemblies in a cask was subtracted from the SNM inventory, even though some of the assemblies in the cask were missing parts of fuel rods. Fuel fragments from these stainless steel fuel assemblies are known to have remained in the SFP. Additionally,' most, if not all, of the fuel rod that was cut 'into segments from assembly A49 was most likely missing from assemblyA-49 when it was shipped to' NFS in August 1969.

The'SNM inventory thus became inaccurate following'the beginning of shipments to NFS and continued to be inaccurate until corrected in 2004. As a result of the inaccurate SNM inventories, inaccurate material status reports were submitted to the AEC/NMMSS/NRC in the time period of 1969-2003 There is evidence to support the proposition that PG&E had initially intended to ship.the container of fuel fragments'to NFS forreprocessing. If that had occurred, the material status reports would have been correct,`at least after the time that both the fragments and the stainless steel-clad fuel assemblies they had come from would have' been shipped.

Fuel assembly A-49 was discharged from the reactor in the fall of 1965 following three operating cycles. In September 1968, three 18-inch fuel rod segments' were cut from a comer rod of assembly A-49..Records show that the cut segments were placed in a sealed 'pipe container for shipment to Battelle Memorial Institute for performance of an experiment to determine potential cask 5 PG&E did not commit to compliance with Regulatory Guide 5.29 and did not incorporate the provisions of ANSI N15.8-1974 into the SNM control and accountability procedures at HBPP.

6-9

'IIn'-

coolant contamination from failed fuel shipments. The experiment was subsequently cancelled and the segments were not shipped to Battelle. The last written record regarding' the three segments states that they were returned from a shipping cask to the'SFP for storage on September 27, 1968. A former HBPP engineer recalls that the pipe container with the fuel segments was hung on the side of the SFP by'a lanyard and tagged (Reference 8). Shortly after this, the HBPP engineer left HBPP for another job. Since the time the pipe container was hung on the side of the pool, the SNM in the three fuel rod segments was not properly controlled, accounted for, and inventoried.

6.3.5 ION CHAMBERS During an SFP cleanup campaign in 1985, using an approved HBPP procedure (Reference 9), incore strings containing ion chambers were' cut into sections for more efficient storage in the SFP and for shipment of nondetector-containing sections' to low level waste disposal sites. This procedure provided both a measurement criterion and a dose-rate criterion as methods to identify the location of ion chambers in the incore strings. The dose-rate method has since been shown to be unreliable. Documentation shows that the cut incore sections contained a total of 54 ion chambers, each containing a small amount of SNM.

These 54 ion chambers combined contained less than 0.7 gram of U-235. The 1985 procedure for determining the presence of ion chambers in incore sections proved inconclusive when used for low dose incore sections in. 2005. As a result, these low dose incore'sections were, by procedure,' physically opened and visually examined to verify the presence or absence of ion chambers. Using these methods, on February 22, 2005, PG&E determined that there were only 50 complete and three partial ion chambers stored in the SFP, indicating that one complete and three partial ion chambers,' thought to have been stored in the SFP for the period 1985 through early 2005, were not properly controlled and accounted for.,

6.4 EVENTS DESCRIPTION.

A chronological description of the events and conditions that led to the problem considered in this cause analysis is provided in this section. The chronologies listed below address fuel fragments, missing fuel rod segments, and missing incore ion chambers. Charts illustrating the events and causal factors are provided in Figures 1 through 3.

Events - Fuel Fragments (Figure 1)

1.

Stainless-steel clad fuel failures that produced fuel fragments occurred during reactor operation in 1965 through 1967.

2.

Fuel fragments were released into the SFP in 1966 during fuel assembly inspection and cleaning.

6-10

3.

Fuel fragments were stored in the SFP without tracking for accountability 6

purposes.

4.

Fuel assemblies were shipped to NFS in 1969-1971, without subtracting SNM from missing fuel fragments."'

5.

After a fuel assembly was shipped to NFS, its SNM content was subtracted in its entirety from the SNM InVeentory.'

6.

From 1969 to 2004, the SNM inventory of record at HBPP did not properly account for fuel fragments and was thus inaccurate.'

7.

As a result of inaccurate SNM inventories, inaccurate material status reports were submitted to the AEC/NMMSS/NRC from 1969 to 2004.

8.

Fuel fragments in the SFP were collected, invent6ried, and stored in containers in the SFP from mid-2004 to March 2005.

9.

The SNM inventory was initially corrected for fuel fragments in September 2004 with additional corrections being made'through March 2005.

10. The annual material status report for October 1, 2003, through September 30, 2004, was corrected for fuel fragments and submitted to NMMSS/NRC on November 30, 2004. A revised report reflecting the identification of additional fuel fragments was submitted to NMMSS/NRC on March 17, 2005 (Reference 1 0).

Events - Missing Fuel Rod Segments (Figure 2)

1.

In September 1968, three 18-inch fuel rod segments were cut from a corner fuel rod in assemblyA49 fora planned experiment at Battelle Memorial Institute that was subsequ ently cancelled.

2.

The segments were placed in a sealed pipe container.and hung on the'side of the SFP on September27,1968.

3.

Despite extensive searches, no records have been'located describing the movement ordisposition of the three fuel rod segments since their storage in the SFP in Septeber 1968.'

6 Historical documentation shows that when fuel fragments were discovered on the floor of the SFP they were placed In one of three contairiers' in the SFP, but they were not characterized for purposes of SNM accountabiity and inventory.' In the 1960s ard 1970s, fragments were placed in what was then 'called the'

&garbage can" (later called the central storage container) and during the 1970s and 1980s in interim storage containers; in a failed fuel can (five fragments); or the UD6N container (eight fragments). Only two fuel fragments were located on the floor of the SFP during the intensive search for the A-49 fuel rod segments'and fuel fragments from June 2004 through April 2005.

6-11

RILL

4.

Assembly A-49, from which the segments were cut, was shipped to NFS for reprocessing in 1969.

5.

Inaccurate material status reports were submitted to AEC/NMMSS/NRC from 1969 to 2004.

6.

In June 2004, the three fuel rod segments were declared missing-and the NRC was formally notified on July 16, 2004.

7.

Searches of the SFP and other plant areas through early 2005 have failed to locate the fuel rod segments.7 Events - Missing Incore Ion Chambers (Figure 3)

1.

Using approved procedures, incore strings containing ion chambers were cut into sections with a total of 54 sections containing ion chambers stored in the SFP in 1985.

2.

Approximately 90 incore sections presumably containing 54 ion chambers were stored in SFP containers.

3.

Most incore string tubing believed not to contain ion chambers was shipped offsite in 1985.

4.

The missing ion chambers were not controlled and accounted for and were erroneously included in the SNM inventory in the period 1985 to 2004.

5.

The physical inventory of ion chambers was initiated in 2004.

6.

Visual verification in early 2005 of the quantity of incore ion chambers stored in the SFP showed 50 complete ion chambers and 3 partial ion chambers.

7.

On February 22, 2005, one complete and three partial ion chambers were declared missing and the NRC was notified 6.5 CONSEQUENSES, CAUSES AND BARRIERS The causes that led to the problem analyzed in this report were determined by systematic application of the checklists contained in HBPP procedure HBAP C-12 #2, uCause Investigation Guidelines" (Reference 12). In particular, the Step 3 Checklist, "Analyze the Event" was used to determine causes. Much of the material in Reference 12 is based on The Phoenix Handbook (Reference 13).

7 Although the segments have not been positively located, there is reasonable evidence consistent with the proposition that fragments from' the three 18-inch-long fuel rod segments along with remnants from the A-49 fuel rod may be amongst the fuel fragments in the SFP (Reference I1).

6-12

This section describes the consequences, causes, and barriers for the three issues of concern (i.e., fuel fragments, missing fuel rod segments, and missing ion chambers).

Also addressed is why the SNM control and accountability problems were not recognized sooner.

6.5.1 CONSEQUENCES As recommended in the Step 3 Checklist of HBAP C-12 #2,the first step in developing the causes is to define the consequences associated with the fuel fragments, the missing fuel rod segments, and the missing incore ion chambers based on the chronology of events described in the previous section of this report. A possible consequence for each issue is the issuance of one or more notices of violation (NOVs) by the NRC, as noted in their interim inspection report of April 6, 2005 (Reference 14).' Such NOVs, while of potential significant concern to PG&E, do not affect the determination of causes and are not discussed further in this report.

The consequences discussed below are based on their estimated order of importance for each issue.

For the fuel fragments issue, the consequences were determined to be:

1. Fuel fragments were not properly controlled and accounted for in the time period of 1965 to' mid-2004.'

2. Inaccurate material status reports (388/578 and 741/742 forms) were submitted to the AEC/NMMSS/NRC in the time period of 1969 through 2003.

For the missing fuel rod segrnents, the consequences were determined to be:

1. Loss of control and accountability'of the missinfg fuel rod segments.

2. Failure to properly include thethree fuel rod segments in the SNM inventory, which introduced additional inaccuracy into the material status reports submitted to the AEC/NMMSS/NRC in the time period of,1969 through 2003.

3. Adverse public relations have resulted from the missing fuel rod segments. This impact has been partially mitigated by assurances provided by'PG&E and's-up00orted by the NRC that this event has had no effect On the health' and safety of employees or the general public.

For the missing incore ion chambers, the consequences were determined to be:

-I.j........

6-13

1. Loss of control and accountability of the missing ion chambers.

2. Failure to properly include the SNM in the missing ion chambers in the SNM inventory (less than 0.15 grams), which introduced additional uncertainty in the material status reports submitted to the NRC from 1985 through 2003.

For each consequence, the question 'Why Did This Happen" was asked and answered repeatedly. The results of these analyses are presented in three consequences charts shown in Figures 4 through 6.

6.5.2 CAUSES As shown in Figures 4 through 6, the causes for the three issues of concern in their estimated order of importance are:

For the fuel fragments, the causes were determined to be:

1. Plant management did not require development of procedures for control and accountability of fuel fragments.

2. Plant culture in the 1960s and early 1970s encouraged individual problem solving, rather than development and use of procedures for noncomplex evolutions. This approach resulted in activities that were either performed without procedures, or with procedures that would be considered inadequate by current standards.

3. The SNM Custodians were not adequately trained on control and accountability of SNM (Reference 17).

4. There was no specific regulatory guidance for the control and accountability of fuel fragments.8

5. There was no specific industry experience or standards for control and accountability of fuel fragments.

For the missing fuel rod segments, the causes were determined to be:

8 The issue of specifying control and accountability requirements for loose fuel rods and fuel fragments is specifically addressed in a recent General Accounting Office Report to Congressional Requestors (Reference 16). The NRC commits in the report to development of guidance concerning control and accounting of spent fuel rods and fuel rod pieces, as well as additional guidance for the conduct of physical inventories.

Compliance-based inspections and audits performed by both PG&E and the AEC with full knowledge of the existence of fuel fragments did not raise control and accountability issues and thus reinforced accountability at the fuel assembly, not fragment, level.

6-14

1. Plant management did not require development of procedures for control and accountability of fuel fragments.

2. Plant culture in the 1960s and early 1970s encouraged individual problem solving rather than development and use of procedures for noncomplex

.evolutions. This approach resulted in activities that were either performed without procedures, orwithprocedures that would be' considered inadequate by current standards.

3. The SNM Custodians were n6t adequately trained on control and accountability of SNM (Rdfe'renc'e 17).

4. There was no specific regulatory' gUidance for the control and accountability of fuel rod segmernts.8

5. There was no specific industry experience or standards for the control and accountability of fuel rod segments.

For the missing incore ion chambers, the causes were determined to be:

1. An inadequate procedure was used to determine the location of ion chambers in incore strings during' cutting operations'(Reference 9).'

2. The SNM Custodians were not adequately trained on control and accountability of SNM (Reference 17).

3. A personnel error - cognitive, for failure to follow the SNM control and accountability procedure for incore ion chambers.

6.5.3 BARRIERS Barriers related to loss of control and accountability of SNM in the form of fuel fragments, fuel rod segments, and incore ion chambers are addressed in this section. The barriers have been categorized as follows:

Effective barriers Ineffective barriers

• Missing barriers

-Unchallenged barriers.--

PG&E believes the impact of effective barriers during the course of these events greatly exceeds the impact of the ineffective or missing barriers. The effective barriers protected public and worker health and safety, controlled and accounted 6-15,

K a1L-for all but a very small amount of SNM, and protected against unauthorized removal of SNM from the HBPP site.

EFFECTIVE BARRIERS Radiation Protection Program:

Control of Fuel Assemblies:

Physical Security:

Maintained public and worker health and safety throughout the course of these events.

With the exception of the relatively small amount of SNM contained in fuel fragments and the three missing fuel rod segments, the SNM in fuel assemblies has been adequately controlled and accounted for throughout the life of the plant.

Has protected HBPP SNM from unauthorized removal from the plant site.

INEFFECTIVE BARRIERS SNM Procedures:

SNM Custodian Training:

Inventory Practices:

SNM Inspections/Audits:

Management Oversight:

HBPP SNM control, accountability, and inventory procedures from 1965 to 2004 did not address fuel fragments or fuel segments.

The SNM Custodians were not adequately trained on control and accountability of SNM.

This adversely impacted their ability to accurately track, inventory, and account for SNM in PG&E's possession at HBPP.

SNM inventories of SFP contents were generally limited to confirmation of SNM relocated since the last inventory. This substantially reduced the likelihood SNM in the form of fuel fragments or fuel rod segments would be properly tracked and accounted for.

Inspections and audits by the AECINRC and audits by PG&E Quality Assurance were compliance based, and did not focus on possible shortcomings in procedures, such as failure to address fuel fragments and fuel rod segments.

HBPP plant management did not require development of procedural requirements for 6-16

control and accountability of fuel fragments and

'fuel'segments.

MISSING BARRIERS Regulatory/Industry' Guidance:

Inventory of Record:

There was no specific regulatory guidance and

.no industry guidance for control and

-accountability of fuel fragments and fuel rods or fuel rod segments).

HBPP lacked a single, integrated, readily

'retrievable "inventory of record" against which Ito compare physical SNM inventories' from

.1963 to 2004. Without an accurate basis, accurate physical verification could not be performed.

Inventory Reconciliation:

SNM inventories performed prior to 2004 were

! insufficient to identify the fuel fragments, missing fuel rod segments, and missing ion chambers.

UNCHALLENGED BARRIERS Criticality Control:

Criticality control was not challenged by the fuel fragments or three missing fuel rod segments, no matter where they were located.

6.5.4 UNTIMELY RECOGNITION OF LOSS OF SNM ACCOUNTABILITY PG&E believes HBPP failed to recognize, at an earlier time, the SNM accountability loss associated'with the fuel fragments, missing fuel rod segments, and missing ion chambers because:

SNM Custodians were 'not adequately trained on the control, accountability, and inventory of SNM.

• The SNM procedures did not address fuel fragments, fuel rod segments, or the creation of records to track fuel fragments and fuel rod segments.

HBPP accounting practices did not effectively compare physical inventory with a definitive "inventory of record.'

6-17

M1 L.

6.6 RECOMMENDED CORRECTIVE ACTIONS Soon after HBPP identified the missing fuel rod segments from A-49 and problems with the SNM control and accountability, TRGs were established and NCRs were generated.

Eventually, the NCRs were combined into one. This NCR, HB3-04-QC-N005, was established on June 30, 2004, to investigate and resolve all SNM inventory and accountability issues that first surfaced in November 2003 with the discovery that fuel fragments may not have been properly accounted for in SNM inventories -and material status reports.

Following completion of the Project and development of the causes contained in this Cause Analysis Report, the TRG for NCR HB3-04-QC-N005 discussed and agreed on the corrective actions in Sections 6.6.1 and 6.6.2. Immediate corrective actions are actions taken soon after a problem is identified. Corrective actions to prevent recurrence are usually actions taken in a longer time frame. However, some immediate corrective actions may become corrective actions to prevent recurrence if they meet the criteria to prevent recurrence.

6.6.1 IMMEDIATE CORRECTIVE ACTIONS (ICAS)

ICA 1: HBPP procedures have been revised to require specific detail(s) regarding the documentation of location of fuel components as they are identified in the SFP. A full cataloging and characterization of the contents was performed to ensure a complete and accurate accounting of all SNM in PG&E's possession at HBPP, down to the fragment level (This ICA also became CAPR 3).

ICA 2: Prepare draft revisions to SNM reporting forms 741, 742, and 859 based on the results of a formal PG&E calculation prepared to reverify the SNM inventory as reported to NMMSS/NRC in October 2003. The calculation used a technique developed to convert measured quantities of fuel fragments to mass of SNM. The assumptions used in the conversion were documented in the SNM inventory.

ICA 3: Developed procedures that will measure and quantify SNM waste and fuel fragments. These procedures will result in corrections to the SNM inventory that will constitute an acceptable long-term corrective action (This ICA also became CAPR 1).

6.6.2 CORRECTIVE ACTIONS TO PREVENT RECURRENCE (CAPRS)

CAPR 1: Develop procedures that will measure and quantify SNM waste and fuel fragments. These procedures will result in corrections to the SNM inventory that will constitute an acceptable long-term corrective action (see ICA 3).

CAPR 2: Complete a detailed SNM inventory based on results of the ongoing SFP work.

6-18

CAPR 3: Revise HBPP procedures to require specific detail(s) regarding the documentation of location of fuel components as they are identified in the SFP.

A full cataloging and characterization of the contents should be performed to ensure a complete and accurate a6counting of all SNM in PG&E's possession at HBPP, down to the fragment leve6l'(see ICA 1)

CAPR 4: 'Revise HBAP D-7 "Control and Accountability of Special Nuclear Material and Waste'Shipmrents" annd STP 3.6.6 "Annual Special Nuclear Materials Physical Inventory and Spent Fuel Pool Cover Seal Verification" to address the issue of the physical inventory offnon-fuel SNM in the pool.

CAPR 5: Revise procedures EDOI B-3, B-5 and HBAP D-7 to ensure that procedures used for future work in the SFP and other areas where SNM may be located shall include provisions for control and accountability of fuel fragments and non-fuel SNM.

CAPR 6: Create a qualification" for the SNM Custodian and persons designated to be SNM Custodian.

6.7 REFERENCES

1.,HBPP Procedures for Control of SNM, dated July 1968, February 9, 1973, December 1975, July 1982, and December 1983.

2.

"Fuel Accountability During Fuel Inspections", Internal HBPP Memo, July 20,1966.

3.

"Fuel Inspection Program-During Period July 13-17, 1966," Internal HBPP Merno, July 18,1966..

4.

AEC/NRC Inspection Reports for Surveys/Audits'of SNM at HBPP, dated February 10, 1965, August.19, 1969, December 5, 1972, and September 12,1975.

5.

AEC Inspection Reports Related to Fuel Failures at HBPP, dated December 13, 1965, and August 23, 1966.

6.

ANSI Standard 15.8-1974, "Nuclear Material Control Systems for Nuclear Power Plants," October 22, 1974.

7.

Regulatory Guide 5.29, "Nuclear Material Control Systems for Nuclear Power Plants," Revision 1, June 1975.

8.

Interview with J.M.G. (former PG&E engineer), February 3, 2005.

6-19

9.

HBPP Temporary Procedure 11/25/85 No. 2, "Cutting In-Core Assemblies."

10. "Revised Annual Material Status Reports for the Period Ending September 30, 2004," HBL-05-007, March 17, 2005.

11.

"Evaluation of Nuclear Fuel Rod Fragments and Inference to Fuel Rod A-49 at Humboldt Bay Power Plant," Report prepared by ATI Consulting, March 31, 2005.

12. HBAP C-12 #2, "Cause Investigation Guidelines."

13. William R. Corcoran, 'The Phoenix Handbook," (Event Evaluation Manual),

March 8, 2000.

14. Special Inspection Interim Report 050-00133/05-001,- NRC, April 6, 2005.

15.

HBAP D-7, "Control and Accountability of SNM and Waste Shipments."

16.

"NRC Needs to Do More to Ensure that Power Plants Are effectively Controlling Spent Nuclear Fuel," GAO-05-339, General Accounting Office Report to Congressional Requestors, April 2005.

17. Interview with R.T.N. (former HBPP SNM Custodian), May 9, 2005.

FIGURE!

1.

2.

3.

4.

5.

6.

Event and Causal Factors Chart - Fuel Fragments Event and Causal Factors Chart - Missing Fuel Rod Segments Event and Causal Factors Chart-Missing Incore Ion Chambers Consequences Chart - Fuel Fragments Consequences Chart - Missing Fuel Rod Segments Consequences Chart - Missing Incore Ion Chambers 6-20

rquired procedure fr l

rquire procedures for comple evolutions-A\\

tracking fragments No applicable procedural requirements i industry guidance for

-fragments' Fuel failures during reactor operation produced fuel fragments 1965-1967

- Fragments ::

were released into SFP during fuel

. assembly inspection and cleaning in

- - - 1966.

i Fragments were stored in SFP containers without tracking for accountability Fuel assemblies were shipped to:

NFS in -

1969-1971 without subtracting SNM from missing fragments I

Complete fuel assemblies were subtracted from SNM inventory when shipped I

SNM inventory of record at HBPP did not include fragments 1969-2004 A7 Causal Factors D Events Figure 1. Event and Causal Factors Chart-Fuel Fragments (Sheet 1 of 2)

A

' recognize impact of

_/'adequately trained on shipping fuel assemblies

\\control and accountabilit'

.,,.;inaccurate Procedures. "Fuel.f material statuse2 SFl to~collect, ne to AEC/NMMSS/

charaterie, andl storei NRC 1969 to 2004 str ulto M

fragments inspections and audits did not identify any issues related to fuel fragment ragments in.

collected,'.

toried,'and:

I Mid-2004 arch 2005 HBPP SNM.,

' inventory corrected for fuel:

fragments Sept.

2004 to' March 2005

.-Material status-,

report corrected.

l, for fragments -.

revised and submitted 3/17/05 Figure 1. Event and Causal Factors (Sheet 2 of 2)

Chart - Fuel Fragments

Plant culture only required Pant mg'mt did not requir procedures for complex procedures for tracking fuel e

is srod segments applicable procedL requirements guidance for fuel rod -

.Three 18-inch fuel rod segments cut from assembly A-49 rod in September 1968

.I,-.-,-

I

-Segments l, placed in pipe,

-container and, hung on side:

' of SFP on 9/27/68 No' reco rd' of As movement or disposition of se segments since cu 9/27/68 re

-9 sembly A-49, from which gments were t, shipped for processing in 1969 ft

Figure 2. Event and Causal Factors Chart - Missing Fuel Rod Segments (Sheet 1 of 2)

Inaccurate Segments declared material status missnged reports Jn20 B

submitted to uand NRC:

AEC/NMMSS/

fral NRC 1969 to, notiredlon 200-.

7116/04

/

\\

/SNM Custodians did nct\\

SNM Custodians not recognize impact of shipping fue adequately trained on control assembly A-49 without and accountability of SNM documenting whether or not the segments were included Searches of SFP and other plant areas through early 2005 have failed to locate:

segments;,','!

Figure 2. Event and Causal Factors Chart - Missing Fuel Rod Segments (Sheet 2 of 2)

na equate roced ed to determine, 10 0

of ion chambers in'incote na equate physi

. inventory records ersonnel did not compl

.aintained for movement with SNM control and and disposition of ion accountability p

mbers, Incore sMrings' containing 54 ion chambers cut into sections 'and stored in SFP in 1985

Approximately 90.

incore sections' containing 54 ion, chambers stored' in SFP containers Most incore string.

tubin'g'not--:

containing ion chambers shipped offsite in 1985 The missing ion chambers were' not controlled and accounted for andA were erroneously '

Included in SNM inventory - 1985 to 2004 SNM Custodians' nob adequately trained on control and accountability of SNM

,./

Figure 3. Event and Causal Factors Chart - Missing Incore Ion Chambers (Sheet 1 of 2)

Phy sical inventory of ion chambers.'

initiated in 2004 Verification in' early'2005 showed only'50 complete and 3 partial ion chambers in SFP ft "OnQ2122105, joined complete ahdd.,

three partial ion-chambers were.<

declared missing and the NRC was notified Figure 3. Event and Causal Factors Chart - Missing Incore Ion Chambers (Sheet 2 of 2)

Consequences

1. Fuel fragments not properly controlled and' accounted for:'

1965-2004

2. Inaccurate.-

material status reports submitted to AEC/NMMSSI NRC.

Why?

',',., Fuel'+:f,.'.`

,.fragments not included in SNM' inventory 1969-2004 Why?

I No control

'. and-'

accountability

r.

records maintained '

.for fuel fragments Why?

-; -No-I

'..procedural.

requirements to' collect, characterize,'

and store fuel fragments Why?

Plant management did not.' -

require.

procedures for control and accountability of fuel fragments

<cause>

Why Why?

No specific regulatory guidance for control and.

accountability of fragments

<cause>-

Plant culture.

encouraged individual;'

problem solving' rather than procedures for non-complex evolutions

<cause>

No specific.

industry experience or standards for control and accountability of fragments

<cause>

Why?

Why? -

• SNM Custodians not adequately trained on control and accountability of SNM I-.- <cause>

Figure 4.

Consequences Chart - Fuel Fragments

Consequences I1. Loss of control and accountability of missing fuel rod I segments Why?

2. Submittal of Fuel rod segments inaccurate not properly Meastatus i.e~~

mtera sts-I included in SN M.'

-,-;,reports J.,

,;,'nv'entory,,'.

Loss of control

3. Adverse public sand accountability,=

relations of fuel rod segments No control &

accountability records maintained for fuel segments

' No proceduralt requirements for control &

accountability

. -offuel.

- segments I, Plant Mgmt did 'not require procedures for control and accountability

<of fuel rod, segments

.<cause>-

4b 4b 40 No specific regulatory guidance for control and accountability of fuel rod segments

<cause>

Plant culture encouraged I individual problem solving-'rather than' proceduesfor non-complexJ.

evolutions

<cause>

why?

SSNM Custodians, l Inot adequately,

trained on control T and accountability of SNMI

. ' <cause> I l

No specific.

industry experience or '

standards for

' control and accountability of Ifuel rod segments

<cause>

Figure 5. Consequences Chart - Missing Fuel Rod Segments

Consequences

1. Loss of control and accountability of missing ion -

]

chambers: '

Personnel error -

cognitive Failure to follow SNM control &

accountability procedure

, cause>.-;:

U.

Missing ion, charmbers c.

erroneously;

,included in SNM inventory 1985-2004 Why?

-10 I.

..I~

I...

f.

.I ion chambers

. may have -

' ' been,.-'

inadvertently shipped off-site in 1985 Why?

7 Inadequate.

physical inventory,

records, maintained for.

movement and disposition of ion

- chambers Whyl

-O

2. Submittal of,

Why?

inaccurate' '

material status '

' '. reports-'

Inadequate procedure used to determine location of ion chambers in incore strings during cutting

<cause>

Wh ?

SNM Custodians not adequately trained on control and accountability I Iof SNM.

<cause>

Figure 6. Consequences Chart-Missing Ion Chambers

HUMBOLDT BAY POWER PLANT UNIT 3 SPECIAL NUCLEAR MATERIAL CONTROL AND ACCOUNTABILITY PROJECT FINAL REPORT ATTACHMENT 7.1 HBPP SNM PROJECT TIMELINE

TIMELINE KEY NOTE Some Time Une event Name tor the same year may have the same event hem number. This is due to the act that the event items were initially obtained from th sam source document. typicaily a Master Log. In some cas, an actual documint specifically describtng the item event described in the Master Log was subsequently identified. For those specific cases, the original item event number may be revised.

HBPP SNM PROJECT TIMELINE Sheet I of 45

HBPP SNM PROJECT TIMELINE Sheet 2 of 45

1=

SNM A-7 sLca -W HBPP SNM PROJECT TIMELINE Sheet 3 of 45

HBPP SNM PROJECT TIMELINE Sheet 4 of 45 I,

HBPP SNM PROJECT TIMELINE Sheet 5 of 45

HBPP SNM PROJECT TIMELINE Sheet 6 of 45

AEC ow.d ro.

.-for UtW Cu.

& Ao-Mnb4It -

fl14W7T(S7.-2)

HBPP SNM PROJECT TIMELINE Sheet 7 of 45

IMEUNE I

)IHBPPUn*

¶0 1968 SPEICAL NUCLEAR MATERALC-W1ATROJC Z

PROCCOUR..

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(RLOC 176400)

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(3)1WV ARC 0003 (OM-119)OnR/1ot Sheet 8 of 4

1969 HBPP SNM PROJECT TIMELINE Sheet 9 of 45

HBPP SNM PROJECT TIMELINE Sheet 10 of 45

HBPP SNM PROJECT TIMELINE Sheet 11 of 45

un72 NFS MRbSo.lpr P-g 8p nb8 hI ordo10 In28 170r g 2.87lo48Ih Mci/-lomnot-Mwrnuont Fallynow nop nr

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2C228) 888 (RL80002 1428897 2-8 HBPP SNM PROJECT TIMELINE Sheet 12 of 45

HBPP SNM PROJECT TIMELINE Sheet 13 of 45

HBPP SNM PROJECT TIMELINE Sheet 14 of 45

MO IMUM3 tr FI.04 88FF USAARAIASIA. ~CONTROLOC PCA e

0 OF 1PECIAL C

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C-I NULA ~MATRL 0-30

.. 1-1/7 Raw. IA-MARX 0JR 1O.O.S I.04 975-18 I -

I I

I I

i finI IAn 7A1 15 (RIOC 00213014)111175.1 10 1 (RLOC 0044.A37A)

HBPP SNM PROJECT TIMELINE Sheet 15 of 45

TIMEUNE 1976 Ha)>m~

HOPLI 196" 0

CONTROL OF PCIA 8

NTROL OF 801044,.

8W110 3

ROL5081OF 4.

NUCLEAR RIALER 41350 NUCLEAR MATERIAL.

C-35S NUCLEAR MATERIAL O.35 R.6 17.12175 RO., 18 -2/76 R.Y 16-276

,R.O 05-2S)l1701 IRLOC S6.G8K)

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19haonl) 07810 1_)01)76-Il HBPP SNM PROJECT TIMELINE Sheet 16 of 45 I

TIMEUNE lB ln HWU3MARURRl Y3No 1977 NUCL TERIAL C0-30 NUCLEARMATERIALC0-300 R.N2 7

-II0l RIA.29-W47 (RL. 0006

)

2 1976 *8

/

RILC 0005-2654)1 1075-1

/

RHBP UNR 3AdVRN010 fold CONTROL 0F SPECIAL NUCLEAR MATERIAL C-OR Re5 o

2 -1127 a

(BLOC inRS.w2RN4(

/175-18 197T 8 MA-NSWVV.

$NUC-W1T RPps HBPP SNM PROJECT TIMELINE Sheet 17 of 45

1978CONITROL OF SPECIAL.

SNM C - Wr II UCLEAR ATRl.C.28 I

R-~32-12fl I

IO0CMR 70 R8II Rwd Wh oI, qIoi (RLOC XVCX)12

/1870-4

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3ILCOR8-0R)/1782 RLC9728262/ 87-RC

~-VHBPPkSNM (MLOC03US7M t

9MI2IRV7PROJECTll L--

8-lTIMR.LINE R.

C-Sheet 18 of 45

I IMEUNE l

1979

/P~raS \\,*IA

. l HIAPP Un 3

CONTROLOF PCIl CONTROL OFSPCA AUCLEA ATERIAL C-SAC NUCLEAR MATERIAL C40-(,LoE OC6S54) i 16

/(A ORev-ZSERI is-iS HBPP SNM PROJECT TIMELINE Sheet 19 of 45 I

I

HBPP SNM PROJECT TIMELINE Sheet 20 of 45

.1

CONTRL OF SPECIA CONRO O3 PECIA NUCA MATERIAL 0.350 mNUCER TRALCC 501R.48-INTSR RLC0RRN26Rl 1 75-IS Ry.f-7121 SR-HBPP SNM PROJECT TIMELINE Sheet 22 of 45

CONTROLOF SPECLOF NUCLEAR MATERUAL CR60

\\W.fl-7i l67 SHE PP?

EnU43MinJtN PtcDWjr.

CONTROL OF SPECIAL NUCLEAR MATERIAL C-R50 Rim. a-I=8 HBPP SNM PROJECT TIMELINE Sheet 23 of 45 I I I

HBPP SNM PROJECT TIMELINE Sheet 24 of 45

HBPP SNM PROJECT TIMELINE Sheet 25 of 45

m m61,11.

-6,6))

44,044 (RLOC 263-173.363-26.360- 343-010 3604.012.300-067,364-30 3604035 300-077200 243. 3002462. 362.36 026 o7 107 3402 36316 6

3600.330. 30143M,

-301-4413.3M0104441, HBPP SNM PROJECT TIMELINE Sheet 26 of 45

HBPP SNM PROJECT TIMELINE Sheet 27 of 45

g

~I 1

Pacific Gas & Electric Humboldt Bay Power Plant Unit 3 Special Nuclear Material Project HBPP SNM PROJECT TIMELINE Sheet 28 of 45

lHPP P.

M.O.f NPAP D-7,

.?

Nor 11 SilwlN fl I & 2I Ca.cd 1I8 W

SWp,..d by HBP D0.7 (RLOC 0437b-DOMlf IN" HBPP SNM PROJECT TIMELINE Sheet 29 of 45

2 7MEUNE]

l1990 HBPP SNM PROJECT TIMELINE Sheet 30 of 45

Spe.Vd 10 kld N

HBPP SNM PROJECT TIMELINE Sheet 31 of 45

l TIMEUNE I

1992 I

I I

NRC RO LkR

..... AblSy IW.k NRC Un1 *

(RIOC antOe) 1 9R24 (RLOC I24029)

RI.2

(

R LC 5

l9O2-(

L Mnlr67R) *RRZ.S HBPP SNM PROJECT TIMELINE Sheet 32 of 45

HBPP SNM PROJECT TIMEUNE Sheet 33 of 45

HBPP SNM PROJECT TIMELINE Sheet 34 of 45

HBPP SNM PROJECT TIMELINE Sheet 35 of 45

I nMEUNE l

1996l MM 10 CFR 70 Frn Rid. pangI.

4n#On1f

.ntWnd 11 Cr keg.

(RLOC XX0XX I Id.I HBPP SNM PROJECT TIMELINE Sheet 36 of 45

IMEUNE l

1997 HBPP SNM PROJECT TIMELINE Sheet 37 of 45

71MELINE 199i HBPP SNM PROJECT TIMELINE Sheet 38 of 45

TIMELNE l

1S999 HBPP SNM PROJECT TIMELINE Sheet 39 of 45

I TIMEUNE l

2000 HBPP SNM PROJECT TIMELINE Sheet 40 of 45

HBPP SNM PROJECT TIMELINE Sheet41 of 45 I

I Annul -1 Nor By A

PRE F.Wl P~ C.-

V.Wl~, ST'P 3.6.6. R-v I8A 1024.02 Lll
lr I HBPP SNM PROJECT TIMELINE Sheet 42 of 45

LMELINE 2003 HBPP SNM PROJECT TIMELINE Sheet 43 of 45

HBPP SNM PROJECT TIMELINE Sheet 44 of 45

NRC 1.

.lh 201:

M.WhlMC.*I and Asftt at R.de and W Sp (CA 2.-it-S NRC Balu 2C001) 1 2005-I Pacific Gas & Electric Humboldt Say Power Plant Unit 3 Special Nuclear Material Project HBPP SNM PROJECT TIMELINE Sheet 45 of 45