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Three Mile Island Researchand Development Program1990 Annual Report

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DOE/ID-1 0289(90)Distribution Category: UC-523
TMI Supplement

U.S. DEPARTMENT OF ENERGY
THREE MILE ISLANDRESEARCH AND DEVELOPMENT PROGRAM
1990 ANNUAL REPORT

February 1991

Idaho National Engineering Laboratory
EG&G Idaho, Inc.
Idaho Falls, Idaho 83415

Praparad for tha
U.S. Department of Energy
Idaho Operations Office

Under DOE Contract No. DE-AC07-76ID01570

ABSTRACT

Defueling of the Three Mile Island Unit 2 (TMI-2) reactor was completed in 1990
transportation, receipt, and storage of TMI-2 core debris. The TMI-2 TechnicalIntegration Office was closed March 1990. Completion, or significant progress toward
completion, was logged in the remaining activities of the U.S. Department of Energy(DOE) programmatic effort of support to cleanup the TMI-2 facility. This reportdiscusses that work and other TMI-2 related cleanup, research, and development
activities conducted during 1990. The major topics in this report include:
as wase

Waste immobilizationeCore debris transportation, receipt, and storagee

Accident Evaluation ProgrameTechnical Integration Program.

Completion of the overall DOE programmatic effort associated with the cleanup of
TMI-2 will be during Fiscal Year 1991.

lii

SUMMARY

upon

Fuel and Waste Handlingthisunderstanding;and(c) generateacomputerized database of TMI-2 research data andand Disposition Program

to use the database to

exercisetodetermine

produce a standard problem
possible nuclear accident

scenarios.

During 1990, the fuel and waste handling anddisposition program continued. Fuel debris canister
preparation, canister acceptance, cask loading, andrail cask shipping, receipt, and storage of core debris
was

During the course of the Accident Evaluation
Program these objectives have been attained: (a) an
understanding of the TMI-2 accident has evolved
during the program that provides information on theconsequences and dynamics of a nuclear accident;

conducted in accordance with the establishedprocedures of the program.

(b) this information was used to develop a detailed

During April of 1990, the 49th and final
shipment of core debris was transported in NuPac

accident scenario; and (c) the TMI-2 database has

12S-B rail casks, which hold seven fuel canisters
each. A total of 342 canisters have been transported

accidents and to assess the effects of those accidents.

the

Idaho

been used to formulate

These

National

Engineering Laboratory(INEL) from Three Mile Island since this activity
started in July 1986. The TMI-2 core debris will betohigh-level

waste

repository

the Accident Evaluation Program.
To

becomes

generate

research

importanttotheenhancement of nuclear safety and to increase theavailable.

understanding of how a nuclear reactor vessel
responds to molten fuel, NRC is sponsoring theReactor Vessel Investigation Project. During 1990,
31 samples were obtained from the bottom headregion of the TMI-2 reactor vessel for this project

Considerable progress in TMI-2 waste disposition
One notable
during the year.
was theataccomplishment
disposition the INEL of
the remaining EPICOR-II prefilters that have beenused for several years in a U.S. Nuclear Regulatory
Commission (NRC) sponsored research program.

wasobjectives are documented in reports thatexamine and evaluate the research performed during

stored at the INEL for up to 30 years or until anational

potential severe nuclear

recordedTechnical Integration Program

national historical landmark located at the INEL

Defueling of the reactor vessel was completed
during 1990. Final defueling, cleanup, and video
inspection of the TMI-2 reactor vessel was
Technical
completed by the end of January.
assessment of the video inspection determined thatan acceptable degree of reactor vessel
cleanup had
been attained.
The goal to reduce the fuelremaining in the vessel to less than 1% of theoriginal fuel inventory had been achieved.

Accident Evaluation Program

Mile

Significant progress in the final disposition of
TMI-2 equipment and material was made.

TMI-2

equipment and material used at the INEL, and caskhandling shipping equipment and materials used at
TMI-2, were evaluated for disposition. Each item
wasidentified for disposal, placed in storage,transferred to other programs, or put on public
display at the Experimental Breeder Reactor I

The DOE Technical Integration Office at Three

Island, operated by EG&G Idaho, Inc., for
DOE, was closed on schedule during March 1990.

The

objectives of the DOE-sponsored TMI-2
develop anunderstanding of what occurred inside the reactor
vessel during the accident in terms of core melt
progression; fission product retention and transport;

This marked the end of over 10-1/2 years of DOE

Accident Evaluation Program are to (a)andand DOE contractor(EG&G Idaho) presence atThree Mile Island. The office coordinated activities

involving several DOE national laboratories, otherfederal agencies, state and local agencies, private
enterprise, foreign countries, and GPU Nuclear
Corporation (the Three Mile Island utility).

material

oxidation, andtemperatures,interactions; (b) develop an accident scenario based

IVCONTENTS
ABSTRACTiii

SUMMARYiv

I.

INTRODUCTION

1

1 FUEL AND WASTE HANDLING AND DISPOSITION PROGRAM

3.

2.1

Waste Disposition

2

12Core Transportation

3

2J

Core Receipt and Storage3

2J.1 Canister Totals
132 Core Accountability

3

14

Abnormal Wastes

515

TMI-2 Records Management

5

3

6

ACCIDENT EVALUATION PROGRAM
3.1

6

DOE Accident Evaluation Program
3.1.1

6

Final TMI-2 Accident Scenario

3.1.2 TMI-2 Daubase and Sundard Problem Exercise
3.1 J

12
4.

2

Sample Acquisition and Examination Program

8
8

Reactor Evaluation Program
4.1.1

6

7

NRC Reactor Vessel Investigation Project

TECHNICAL INTEGRATION PROGRAM
4.1

6

8

Fuel and Core Debris Removal

10

4.1.2 DOE Technical Integration Office

A-l

APPENDIX A-1990 TMI-2 PUBLICATIONSFIGURES1,

2.

Location of TMI-2 core debris—Three Mile bland venus
Idaho National Engineering Laboratory

5

Cutaway view of the TMI-2 reactor vessel

9

TABLES
1.

4

Summary of core debris shipping campaignv

U.S. DEPARTMENT OF ENERGY
THREE MILE ISLANDRESEARCH AND DEVELOPMENT PROGRAM
1990 ANNUAL REPORT
1. INTRODUCTION
Defueling of the TMI-2 reactor was completed
during 1990. Research activities associated withcleanup and defueling continued throughout theyear.
Program accomplishments during 1990

mark located at the INEL.
e

Completion

Economic

TMI-2

final

accident

Completion of final defueling and cleanup

defuelingassessmentofdetermined

that

and

Technical

cleanup.

andDevelopment

problem exercise on TMI-2; publication of aprincipal report of the TMI-2 Core
Examination Program that documents theresults of chemical and metallurgical analysesof samples obuined from the lower part of
the TMI-2 reactor core; completion of a draftVideo inspection of the reactor vessel after
final

Cooperation

summary report, scheduled for publication
during 1991, that explains differences andidentifies the limitations of various computercode calculations used during a sundard

inside the reactor vessel.
ea1991; completion of the Organization forinclude:eofscenario report that will be published during

the

video
inspection
acceptable degree ofreactor vessel cleanup had been attained.
The TMI-2 plant will be ready for monitored
storage during 1991.
anreport that summarizes the core examinationinternationalof angroup ofresultse

investigators participating in the TMI-2 Core
Examination Program.

Transporting three rail cask shipments ofdebris from Three Mile bland to thecore

INEL, bringing the total
that

shipments
processed at

have

to

been

49 rail cask

received

ande

INEL for storage. This99-f
the original postaccident%ofrepresents
thedebris material.

Completion of sample gathering for the
NRC-sponsored Reactor Vessel Investigation
Project. This involved obtaining 31 samples
from the bottom head region of the reactor
vesselenuclear

Disposal of the last four EPICOR-II premiers

will be
and

used

for

research

for

on

the

increasing
safetyunderstanding of how a reactor vessel
responds to molten material

that were used in an NRC research program
at

that

the INEL and at other DOE laboratories.

The filters were disposed of in concrete highintegrity conuincrs (HICs) at the Radioactive
Waste Management Complex (RWMC)

elocated at the INEL.
a

Final

disposition of TMI-2 equipment andmaterial. This involved inventorying all TM I-

2 equipment and material used at the INEL,
andcask-handling shipping equipment andmaterials used at TMI-1

Each item on theevaluated

Inventory

Ilm

was

deliberation

wasmade to dispose,

and

a

place

in

program closcout activities. As part of thesecloscout activities, this 1990 annual

storage, transfer to other programs, or to put
itonpublic display attheProgress toward closure of the overall DOE
programmatic effort with completion expectedduring Fiscal Year 1991. This progressincluded closing the Technical Integration
Office at Three Mile bland and transferring
the remaining programmatic responsibilities
to the INEL The remaining work includes
final waste disposition activities, records
management closcout, completion of program
reporting and documentation, and minor
reportwill be the final annual report of the ThreeExperimental

Breeder Reactor I national historical land

Mile Island program.

I2. FUEL AND WASTE HANDLING AND DISPOSITION PROGRAM
and materials used at Three Mile Island.

2.1 Waste Disposition

Each item of the inventory was evaluated anda

Steps taken during 1990 in the disposition of
TMI-2 materials temporarily stored at the INEL
include the following:einprograms and organizations, or to put theitem on public display:

Completion of the disposition of the last four
EPICOR-II prefilters, which were developed
as

a

water

treatment

system

used

•

in

disposed of as low-level waste at RWMC
senttothe Waste Experimental
or
Reduction Facility (WERF) at the INEL
for size reduction and then disposed of at

generated by the
TMI-2 accident.8 The filters were disposed of
L of contaminated waterin concrete HICs at the RWMC located at
the INEL The HICs were developed for the

RWMC.

prefilters used at
TMI-2 and for the 46 prefilters that werepreviously disposed of at the U.S. Ecology
commercial disposal facility located in the
The last four filters
state of Washington.
wereof EPICOR-II

disposed of at RWMC(a) cask-handling equipmentthat was contaminated during operations
inside the TAN-607 Hot Shop: cask lift
Those items

included:

used in an NRC research program at

fixture and stand, cask decontamination
tool, lid lift fixture, and shield plugs; (b)the INEL and at other DOE laboratories.

This disposition marked the end of the NRC

program of sampling thecontents

contaminatedof theEPICOR-II

filters. The last samples of the program were

equipmentinthedisposition

sent

to

WERF

for

size

reduction included a mockup canister and
EPICOR-II prefilter. One item, a portionof the cask lift

identified as PF-8, PF-9, PF-20, and PF-27, in

fixture, could

not

be

disposed of at RWMC since it contained

HICs, (b) loading each of the HICs into atransport cask, and (c) transporting the HICs

lead which made it hazardous material.

Arrangements have been made to disposeto the RWMC for burial.

ofitcommerciallyControl,

The last HIC was disposed of at RWMC
during April 1990. This concluded Three
Mile Island programmatic activities in thedisposition of HICs.
ofandvent tool, and dewatering equipment. The

Planning for disposition included the
preparation of detailed operating proceduresfor (a) sealing the four EPICOR-II prefilters,

Dispositionusedequipment
research

program: EPICOR-II prefilter lift fixture,taken during 1989.

e

Items that were of no future

Disposal.

value to the TMI-2 program or otherprograms and organizations were either

decontaminating the approximately 2,120,000

disposaldecision was made to either dispose, placestorage, transfer ownership to other

at

U.S.

PollutionInc., Salt Lake City, Utah.

Several otherpieces of equipment havealso been identified and will be disposedof during Fiscal Year 1991.

TMI-2

equipment andmaterial.
This
activity involved the
preparation of an inventory of all TMI-2
equipment and materials used at INEL
facilities i.e., Test
Area North (TAN),
Central Facilities Area (CFA), Test Reactor
Area; and cask-handling shipping equipment•

Storage. Equipment that could be used at
a later date wasplaced in storage. The
included:equipment-

Two NuPac 12S-B shipping casks andrailcars that were placed on a railroad

spur at CFA.

All cask handling andfrom TAN,
CFA, and Three Mile Island wasinventoried, packaged, if needed, andoperational equipmenta.

A detailed

description of the EPICOR-II water treatment

system and HICs can be found in GEND Report No. 064, U.S.

storedDepartment ofEnergy Three Mile Island Research and Development
Prog-am 1988 Annual Report, dated April 1989.

casks.

2onthe railcars with the rail

Equipment used originally to handle

•

fuel

canisters

1986.* A total of 49 shipments were received at thefrom 1986 through completion of thetransport campaign in April 1990. Five shipments

TAN

during theremoval of core material required forresearch. Reloading of core material
used for research will be accomplishedwith this equipment.
The corematerial
includesdamaged fuelcontrolrodsamples,
spiders, and end
reactor core.
from
the
TMI-2
fittings
atINEL

arrived at the INEL in 1986, 17 in 1987. 12 in 1988,
Table 1 shows all
12 in 1989, and 3 in 1990.

transports of debris through completion of thetransport campaign.

2.3 Core Receipt and Storage

After these components have been

stored, arrangements will be made to

Figuredispose of the canister laydown fixture
and horizontal lift fixture equipment.

approximately 99+% of the core debris wastransferred to the INEL by the end of the transport
campaign in April 1990. This amount accounts forapproximately all the original TMI-2 core debris,and operations were transferred to theircontrol Some of these items included: (a)which was estimated to be 134356 kg.

allcanister-handling equipment,
transferred to TAN Hot Shop Operations,for handling canisters over the estimated30-year storage period of the TMI-2 coredebris; and (b) equipment, transferred to
the INEL Prototypical Consolidation
Demonstration Program, needed forhandling HICs.

The
TAN

2.3.1

the TMI-2

Shop.*The total

Canister Totals.

number ofby the completion of the defuelingcanisters usedcampaign to transport fuel debris from Three Mile
Island to the INEL was 341 Of these, 268 were fuelcanisters, 62

a

were

filter canisters, and

12

were

knockout canisters.
2.3.2 Core Accountability.

scale model of the NuPac 125-B cask, (c)first -of -a- kind, full -sized HIC usedfacility by tractor/trailer where

Storage of TMI-2 core debris at the INEL isplanned for up to 30 years or until a national highlevel waste depository becomes available.

quarter-scalemodel of the NuPac 125 B shipping cask
used in a drop test program, (b) a tenth-atransported in casks bystored in a water pit at the TAN Hot

Reactor I national historical landmark
located at the INEL. Items to be included

(a)

was

debris canisters inside the casks were removed andA display is being
Display.
DOE
participation in
prepared showing
the research, development, and cleanup of
TMI-2. The display will be a permanent
exhibit at the Experimental Breeder

are:debriscorerailcar to the INEL. The casks were delivered to the

Publicthe exhibit

percentage of TMI-2 corethat

Transfer of Ownership. Items that could
be used by other programs, organizations,at

1 shows thedebris that has been transferred from Three Mile
Island for storage at the INEL. The figure shows

A draft of the TMI-2

accountability database report, entitled Uranium
and Plutonium Content of TMI-2 Defueling Canisters,
was completed. The calculated, reportable quantity
core

to

dispose EPICOR-II prefilters, (d) modelsof the damaged TMI-2 core, (c) several
poster displays used at national andof fissile material in each of the TMI-2 canisters
stored at the INEL is identified in the report The

international conferences, (0 photographs

calculationsof all phases of DOE involvement, and (g)The display isvideo uped programs.

were

made

using

detailed

canisterloading information prepared by GPU Nuclear andfrom examinations of TMI-2 core debris stored at

expected to be completed during 1991.

the INEL. The

report will provide the basis by

2.2 Core Transportationa.

The process of transporting TMI-2 core debris
Fuel
to Use INEL was completed in April 1990.
cannier

preparationand cask

Detailed procedure* tor loading, transport, receipt, and alorafc

at rail casks from Three Mile Island to the INEL are discussed
Gl NO Report No 064. US Drpanmeru of Enmp TVrr Hik
bland Ratonh and Otvthtpmtnt Pntg/mn 19M Annua* Report,

loading cycles wereconducted in accordance with the program started in

dated April I9fr?

.1

1

.

Summary of core debris shipping campaign

Accumulated

Cask

Rail

TMI

Shipment

Shipment

Shipping

ArrivalReturnNumber of

NumberNumberDateat INEL

to TMI

Canisters

001

001

07/20/86

07/24/86

08A2/86

7

002

002

09/04/86

10/09/86

14

003

002

09/04/86

09/26/86

21

004

003

005

003

08/31/86
08/31/86
12/14/86
12/14/86

006

004

007

005

12/17/86
12A7/86
01A4/87
02/04/87

01/23/87
12/30/86
02/04/87
02/26/87

008

006

03/07/87

56

009

007

007

Oil

008

012

008

11A9/87

04/20/87
04A6/87
07A0/87
07A5/87
08A9/87
08/26/87
10/03/87
10A0/87
11A5/87
11/24/87
12/08/87

63

010

02A8/87
03/26/87
03/26/87
06/25/87
06/25/87
07/30/87

12/24/87

01/09/88

140

12/24/87

01/18/88

147

01/27/88
02/27/88

154

02/24/88

168a.

01/11/87
02/01/87
02/15/87
03/22/87
03/22/87
06/21/87

28

35
42
49

70

77
84

013

009

014

009

015

010

016

010

017

Oil

018

Oil

019

012

020

013

021

013

022

013

023

014

024

014

025

014

06/21/87
07/26/87
07/26/87
09/13/87
09/13/87
10/25/87
10/25/87
11A5/87
12/20/87
12/20/87
12/20/87
02/07/88
02/07/88
02/07/88

026

015

04/10/88

027

015

04A0/88

12/24/87
02A1/88
02A1/88
02A1/88
04A4/88
04A4/88028

015

04/10/88

04/14/88

05/03/88

196

029

016

05/22/88

05/25/88

06/25/88

203

030

016

05/25/88
05/25/88

210

016

05/22/88
05/22/88

07/03/88

031

07A1/88

217

032

017

12/18/88

12/22/88

01/25/89

224

033

017

12/18/88

12/22/88

01/27/89

231

034

017

12/18/88

02/06/89

238

035

018

02/19/89

12/22/88
02/23/89

03A8/89

245

036

018

252

018

02/23/89
02/23/89

03/28/89

037

02/19/89
02/19/89

03A2/89

259

038

019
019

06/18/89
06/18/89

06/22/89
06/22/89

07/08/89
07A5/B9

266

039
040

019

06/22/89

07/23/89

280

041

020

06A8/89
08A3/89

08/16/89

08/31/89

287

042

020

08A3/89

08/16/89

09/07/89

294

043

020

08A3/89

08/16/89

09A8/89

301

044

021

12/21/89

021

12/21/89

02/24/90
02AO/90308

045

12A7/89
12A7/89046

021

12/21/89

03/05/90

322

047

022

04/18/90

05/06/90

328

048

022

04A8/90022

Storage
Storage335

049

12A7/89
04A5/90
04A5/9004 A 5/90

07/30/87

09A7/87
09A7/87
10/29/87
10/29/87

04A8/90

Casks were placed in storage on railcars

at the Central

4

91
98

105
112
119
126
133

161

03/07/88

175

05/09/88
04/27/88

182
189

273

315

342

Facilities Area of the INEL.

itaaaa_

OCT NOV NC rtl tM MAY OCC PM ASM AIM DtC AM

DSC MSI PSa MAR AM JUL I
cv-aa

Figure 1

.

cv-ae

ev-e?

Location of TMI-2 core debris—Three Mile Island versus Idaho National Engineering Laboratory.

which the material in each of the TMI-2 canisters is
accounted

aT**—^ ev-as asa>~aa*j cv-»ofor and tracked at the INEL.

from contaminated water generated by the TMI-2

The

accident

accountability report will be finalized after GPU
Nuclear (a) completes its accounting of the fuelThe contract period expired in December 1989

material remaining at TMI-2, and (b) provides DOE

between DOE and GPU Nuclear for acceptance ofwith a total accounting of the material transported

abnormal wastes.

to the INEL for storage.

to accept any additional abnormal wastes.

Therefore, DOE is not expected
Also, theTAN Hot Shop at the INEL continues to have theresponsibility for monitoring the wastes. Disposition

2.4 Abnormal Wastesof the three CUNO filters had not been initiated by
the end of 1990.

la 1985 DOE and GPU Nuclear signed contract

DE-SC07-85ID124554.

entitled

Tra importation.

Storage, Disposal

Services for Abnormal Wastes

from

Reactor.*

the

TMI-2

A

total

of

2.5 TMI-2 Records Management

three

shipments of abnormal wastes have occurred under
the coatract:

two in1987 and one in 1988.

programmatic

in

INEL

this data of wastes or until the wastes arc otherwise

arc

file

effortsystem of the DOE

support of

the

TMI-2

The records file system is a computerizeddaubase index of documents relating to DOE efforts
in the research, development, and cleanup of TMI-2.

processed for disposal. The cask is located on aThe
concrete pad ouuide the TAN Hot Shop.
wastesrecords

cleanup is in process of being completed at theshipments were made during 1989 and 1990. The
wastes were transported to the INEL and are stored
ia a concrete cask until disposal facilities exist for

abnormal

TMI-2

A

No

These documents arc

being placed on microfichecopies and will be stored at the INEL TechnicalThe
Library located in Idaho Falls, Idaho.
willbemicroficheandcopiescomputerized database
about
informationtoaccessible
anyone wanting
TMI-2 research, development, and cleanup activities.

conuined in three CUNO

CUNO filters were used in the submerged
demineralizcr system, the water treatment systemused at TMI-2 to remove contaminated particles
filters.

5

3. ACCIDENT EVALUATION PROGRAM
database

TMI-2

a

3.1 DOE Accident Evaluation

andstandard

problem

exercise

Program
Sample acquisition and examination program.

a

The March 1979 accident at the TMI-2 nuclear
reactor was the most severe accident to occur at a3.1.1 Final TMI-2 Accident Scenario.

commercial-operating power reactor in the UnitedStates. Examinations of the reactor core, performed
as part of the TMI-2 Accident Evaluation Program,

TMI-2 accident
formulated

from the central

core

core

regionmaterial relocatedtothe lower headregion of the reactor vessel.

Program to take full advantage of an importantof information provided by the TMI-2
accident.
The objectives of the DOE Accident
Evaluation Program are to:whathappenedduringoxidation,e

Exercise.

theStandard problem exercise calculations,

Organization for Economic Cooperation andDevelopment (OECD). A summary report was
prepared and review comments were obtained from

and

OECD.

Develop an accident scenario based upon thisunderstanding

This report is scheduled for publication
It summarizes differences in theduring1991.

variouscode-calculated

results

for

the

TMI-2

accident and identifies the limitations of the codesused to perform the calculations.

Produce a computerized database containing

3.1.3

Sample Acquisition and Examination
Program. During January, GEND-INF-092, TMI-2

TMI-2 research results, examination data, andsupporting analyses; using the database to
produce a standard problem exercise todetermine possible nuclear accident scenarios.

Core

Bore

Examinations,published.

Vols.

1

and

2,

was

It documents the results of chemical

and metallurgical analyses of samples obtained fromthe lower part of the TMI-2 reactor core.
This
report is one of the principal products of the TMI-2

Sample acquisition and examination of materials
from the reactor vessel, the reactor coolant system,

Core Examination Program.

and the reactor containment and auxiliary buildings

No additional core examinations were performed

conducted

during the course of the DOE
Accident Evaluation Program. U.S. Department of

were

A

based upon the TMI-2 database, were completed
during 1990 by an international task force of theinteractions
e

1989.

3.1.2 TMI-2 Database and Standard Problem

fission-product retention and transport; andtemperatures,andperformed

publication during 1991.

accident in terms of core melt progression;material

upon examinations

accident scenario was completed and is scheduled for

wealthUnderstandThe final

refinedDuring 1990, a final detailed report of the TMI-2

DOE sponsored the TMI-2 Accident Evaluation

e

based

been

description of the accident isprovided in DOE/ID-10289, U.S. Department ofEnergy Three Mile Island Research and Development
Program 1989 Annual Report, dated July 1990.
throughindicated that about half the core melted and about
20 metric tons of molten

hasscenariopart of the TMI-2 Accident Evaluation Program
during 1990. However, a summary review of existingexaminations, performed by participants in theasEnergy Three Mile Island Research and Development
Program 1988 Annual Report, GEND Report No.
064, dated April 1989 provides details and results ofOECD core examination program, was completed in
The results ofduring June 1990.
performed by the various countries
were summarized in areport that was presented toJapanthese examinations.

examinations

The following sections of this report describe theprogress of the Accident Evaluation Program during
1990. The sections are:See Appendix A for a complete list of TMI documents
published during 1990.

a.

aFinal TMI-2 accident scenario

6the OECD Committee

on

the

reactor vesselof the bottom head region of thenozzles
instrument
incorealong with the locations oftubes.
and incore instrument guide

Safety of Nuclear

InsuUatioa (CSNI) and the authors for final review
during September 199a The draft report. EOG-

OECD-9168, TMI-2 Examination Results from theOECD-CSNI Program, Vols. 1 and 2. will be
published during 1991. It will summarize the results

The "boat* samples consisted of wedge-shaped
reactor vessel
pieces cat from the 13-cm thick,
was
15-cm
long and 7.5bottom head. Each sample
forused
cutting the
cm deep. The principal toolingmetalunderwater■boat" samples was a special"boarsamples weredisintegration machine. Fourwith incore
areas
cut from vessel bottom surface"boat*
instrument nozzle remnants or stubs intact; 1 1
incorewithout
were cut from surface areasof the international investigators participating In thisOECD core examination program.

3.2 NRC Reactor Vessel

Investigation ProjectsamplesDaring this 1990 in-vessel metallurgical sampling
program, sponsored by NRC 31 samples wereobtained from the bottom head region of the reactor
This project isvessel for research purposes.
researchtogenerate
important to the
expected (a)enhancement of nuclear safety and (b) to increase
the understanding of the dynamics and consequencesof how a reactor vessel responds to molten fuelinstrument nozzle stubs. The 14 incore instrument

nozzle samples were cut off using an abrasive saw.
The incore instrument guide tube samples were catusing a hydraulicalty driven pipe cutter.

During the cutting of thea4*boat*

sampleswithincorea2 incore instrument guide tube samples.

samplessampleThis cracked area was initiallyduring defueling activities conducted la
July 1989 (sec DOE/ID-10289. U.S. Depanmau ofEnergy Three Mile Island Research and Development
Program 1989 Annual Report, dated July 1990).
From a video inspection of the sample, it appearedthat surface cracking extended deeper into the basemetal of the bottom bead than was initially believed.
However, still photographs, taken after the sample
reactorwas

14 incore instrument nozzle samples

one

vessel.

observed

instrumentanozzles,apparent

from the bottom head region of reactor vessel:
11 *boat* samples without incore instrument

instrument

removed in the cutting sequence was taken from aa
cracked area of the bottom head of Ike

Upon completioa of the sample recovery
operations, the following 31 samples were obtained,
placed inside special sample containers, and removedaincorewithout

11 "boat*removed from the reactor vessel, showed noevidence of significant crack propaption.

Furtheranalysis of the sample was performed underlaboratory conditions. The analysis revealed that no
cracks existed beyond the 0.48-cm thick, stainlesssteel-cladding of the 13-cm thick, carbon-steel

Figure 2 (sec Section 4) illustrates the location

bottom head.

7

4.

TECHNICAL INTEGRATION
and

4.1 Reactor Evaluation Program

Final

a

vacuuming

and-place removal of fuel rod stubs and debris or"rocks" too large to be vacuumed from the bottom
head of the reactor vessel.
Pick-and-place
were conducted with a hydraulicallyoperations
Debris from these
operated vice-grip tool.
was collected in debris buckets and thenoperations

1990 included theloaded into fuel canisters for transfer out of theOndefueling and cleanup of the reactor

lift

debris.

Video inspection of the reactor vessel.
March

30,

1990,

the

DOE

During the final cleanup, shrouds that had beenplaced over the baffle plates on the UCSA region ofTechnical

the vessel, were cleaned and removed from the
These shrouds were temporarily
reactor vessel.

Integration Office at Three Mile Island was closedonschedule.

The office opened in November of

installed in the vessel following disassembly of the

1979, shortly after the TMI-2 accident, to coordinate

defuelingandcleanupactivities atThreebaffle plates and defueling of the core former region

Mileof the UCSA (see Figure 2).

Island.

during defueling operations performed after UCSA
defueling.

4.1.1.1 Final Reactor Vessel Defueling and

Cleanup. Final cleanup was accomplished after thedisassembly and defueling of the lower core support
assembly (LCSA), defueling of the bottom headregion of the reactor vessel, and disassembly anddefueling of the upper core support assemblyThis
activity was(UCSA) baffle plates.
1988
and
1989.
Figure 2
accomplished during

Reactor Vessel

4.1.1.2

Video

Inspection.
defueling and cleanup
Upon completion
activities, a postdefueling, comprehensive video
inspection was conducted to survey for any residual
fuel located in the reactor vessel. The inspection
was performed using a color camera mounted on along-handled tool. The inspection started at the top
level of the reactor vessel and progressed downward
to bottom head region of the vessel.
of final

illustrates the location of the LCSA, bottom headregion, and UCSA
Detailed descriptions of these defueling activities

The video

discussed in the following reports:(a) GEND
No.
U.S.
064,
ReportDepartment of Energy Three
Mile Island Research and Development Program 1988
Annual Report, dated April 1989, and (b) DOE/ID10289, U.S. Department of Energy Three Mile Island
Research and Development Program 1990 Annual
Report, dated July 1990. These reports also provide
information about equipment, such as the pick-andplace vice-grip tool and pump-lift vacuuming system,and other methods used in

The purpose of the

shrouds was to prevent agitated debris fines from
redepositing in the defueled core former region

4.1.1 Fuel and Core Debris Removal

are

Vacuuming was accomplished using a pumpvacuuming system designed to remove finevessel.

vesselacleanup operations started at the top of thevessel and progressed downward to the bottom of
the reactor vessel. These operations involved (a)loose debris and fuel fines and (b) pick-

During January 1990, final cleanup and video
inspection of the TMI-2 reactor vessel wascompleted. This effort resulted in the cumulative
removal to date of 99+% of the original
postaccident debris material.
Defueling activities duringfollowing:

PROGRAM

reactorrequired.

inspection

revealed

where

additional

vesselregions in thecleanup was

While most of the reactor vessel surfaces

clean to the metal, other areas contained alight dusting of core debris fines. As a result of thiswereinspection, the "B" hot leg located in the core
support shield region of the reactor (see Figure 2)
was revacuumed.
Additional vacuuming was also
conducted

in

the

UCSA

where

heavier

concentrations of material were found.

defueling the TMI-2

reactor vessel.

Based upon a technical assessment of the visualevidence provided by video inspection, GPU Nuclear

Final defueling and cleanup inside the reactor
vessel was concluded in January 1990. The defuelingdetermined that an

8

acceptable degree of reactor•B* hot leg

nozzleReactor vesselwanUpper core
supportassembly(UCSA)

Lower core

supportassembly(LCSA)

Incore instrument

guide tube
Incore instrumentlr^Fnrni
Figure 2. Cutaway view of the TMI-2 reactor vessel.

nozzleconfirmed that the cleanup was complete.

cleanup had been effectively attained
following a four-year period of active defueling
operations. The small quantity of core material
remaining in the vessel was in compliance with thereactor vessel defueling goal to reduce the fuelremaining in the vessel to less than 1% of theoriginal fuel inventory.

vesselIntegration Office. The
DOE Technical Integration Office at Three Mile
Island, operated by EG&G Idaho, Inc., for DOE,

4.1.2 DOE Technicalwas closed on March

30, 1990. This marked the endof over 10-1/2 years of DOE and DOE contractor(EG&G Idaho) presence at Three Mile Island.
Final decontamination activities to prepare TMI2 for long-term storage continued throughout 1990.

The Technical Integration Office (TIO) officiallyDecontamination work will ultimately involve theopened in November 1979, shortly after the TMI-2
TIO was the focal point for theaccident.
implementation of DOE's role, mandated by the
U.S. Congress, to participate in the TMI-2 cleanup

Reactor Building, the Auxiliary and Fuel Handling

Building, and the evaporation of 2.3 million gal ofslightly radioactive, processed water. The TMI-2
plant will be ready for monitored storage in 1991.

program, learn from the accident, transfer theknowledge gained to the nuclear industry, andsponsor original research into nuclear reactor safetyissues. The office coordinated activities involving

4.1.1.3 Reactor Vessel Investigation Project
Cleanup. Following final cleanup and inspection ofseveral DOE national laboratories, other federal
agencies, state and local agencies, private enterprise,

the reactor vessel in January,

metallurgical samples
during February from the reactor
vessel for the NRC-sponsored Reactor Vessel
Investigation Project. The project is described in
wereforeign countries, and GPU Nuclear Corporation(the Three Mile Island utility).

obtainedUpon closing TIO, the remaining DOE TMI-2
programmatic functions were transferred to theINEL, a process that has been ongoing for the past
two years.
The remaining work that will carry into
1991 is relatively minor. It will consist of records
management closeout; final waste disposition
activities; completion of program reporting anddocumentation, including the publication of a reporton the history and evaluation of the TMI-2 transportand storage campaign; and minor program closeoutactivities. As part of the closeout activity, this 1990

Section 3.

Sample gathering activities included the use of anand a special underwater metalsaw
disintegration machine to cut samples from selectedareas inside the vessel. As a result of these cutting
activities, additional cleanup was necessary. The
initial effort involved pick-and-place removal ofdebris too large for vacuuming.
This effort was
followed by vacuuming of loose debris from various
in-vessel locations.
Cleanup was accomplished
the
weeks
first
of
March. During mid-March,duringvideo
confirmatory
inspections were performed

abrasiveannual report will be the final annual report of theThree Mile Island program. The scope of these final
closeout activities is not sufficient to warrant

inside the vessel to determine the effect of thecleaning operations.

Review of theanother annual report.

inspections

10

APPENDIX A
1990 TMI-2 PUBLICATIONSIndex of 1990 TMI-2 Publications

D. W Akers et at. TMI-2 Core Bore Examinations, Vols. 1 and 2. GEND-1NF-092, January 199a
R. C Schmitt et al.. TMI-2 Lessons Learned by the U.S.

Department of Energy-A Programmatic
Perspective, DOE/ID- 10276, Idaho National Engineering Laboratory, U.S. Department of Energy,
Idaho Operations Office, Idaho Falls, ID, March 199a

Offtite Shipment of Defueling Canisters, Technical Bulletin 86-33, Rev. 20, GPU Nuclear Corporation,
Middlctown, PA May 30. 199a
U.S. Department of Energy Three Mite Island Research and Development Program 1989 Annual Report,

DOE/ID-10289, Idaho National Engineering Laboratory, U.S. Department of Energy. Idaho
Operations Office, Idaho Falls, ID, July 199a

A-3