Certificate of Compliance

FOR DRY SPENT FUEL STORAGE CASKS

R E

PART 72A

CERTIFqICt UMBER: 1005

REVI:S6t10 NUMBER: 0

PAkCKAb IDENTIFICATION NUMBER: USA/72-1005

pA$lVUMBER: I

TOT6L NUMBER OF PAGES: 3

4'hEAMBLE Thi e is issued to certify thsk and contents, meet thg/ dards set fth in aecribed tnii appj icab1 Aaff t s~ a d

'&XTtle 10, Code ral Sp.d egul 4 X 45 brt 7," 9 Requirement~fo the

Independent S NucliFuef and H Radioactive Waste."

SSS~ Ct ef, \ 

Effective Date:

November 4, 1993

Expiration Date:

Nnvember 3 2013

R >eutE NUCUEt tR REGULATORY C MMISSION

.._, _.,, _ Charles J. Hhney, Chif J

Storage and Transport Sys'j~s-* ranch

Division of Industrial and

Medical Nuclear Safety, NMSS

9311090207 931104

PDR ADOCK 07201005 I

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- -

Certificate of Compliance

FOR DRY SPENT FUEL STORAGE CASKS

10 CFR PART

1. a.

72

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a. Model No: TN-274
b. Description

The TN-24 cask is designed for the storage and shipment of irradiated fuel

assemblies. This certificate addresses spent fuel handling, transfer, and

storage on an NRC licensed nuclear reactor site but does not address any use

of this cask for offsite transportation of spent fuel.

The TN-24 cask body is a cylinder made of SA-350, Grade LF3 forged steel with

a wall thickness of 248 mm (9.75 in.) and a 286 mm (11.25. in.) thick welded

closure on the bottom end. The top of the cask is sealed by a lid which is

292 mm (11.5 in.) thick. The cask is 5105 mm (201 in.) long and 2407 mm

(94.75 in.) in diameter. When fully loaded, with fuel and water, the cask

weighs 103 tonne (113 tons); unloaded it weighs 75 tonne (83 tons).

The cask body has six attachment points for bolt-on trunnions. Four of these

are located near the top of the cylindrical steel forging, spaced 90 degrees

apart, and are used for lifting the cask. Two trunnion supports, 180 degrees

apart, located near the bottom are used when rotating the cask to or from a

horizontal position.

The fuel basket is designed to hold 24 PWR fuel assemblies. The basket is

made of 11 mm thick copper plated borated stainless steel plates formed into

221 mm square cavities. The spacing of the plates provide water flux traps

for criticality control during fuel loading.

A protective cover is bolted to the cask body to provide weather protection

for the lid penetrations. The lid uses a double barrier seal system with two

metallic 0-rings forming the seal. The annular space between the 0-rings is

maintained above the pressure in the cask to prevent flow into or out of the

cask. The TN-24 cask has three containment penetrations; one cask cavity

drain, one cask cavity vent, and one interseal overpressure port. Each of

these penetrations is in the lid.

Neutrons from the fuel are attenuated by borated polymer material 137 mm (5.38

in.) thick encased in a steel shell on the outside of the cask.

c. Drawing

The TN-24 cask is described by drawings in the TSAR.

d. Basic Components

The Basic Components of the TN-24 cask, that are important to safety, are

listed in Section 3.4 of the TSAR.

2
6. Cask fabrication activities shall be conducted in accordance with the reviewed and

approved quality assurance program submitted with the TSAR.

7. Notification of cask fabrication schedules shall be made in accordance with the

requirements of §72.232(c), 10 CFR Part 72.

8. Casks of the Model Number TN-24 authorized by this certificate are hereby approved

for general use by holders of 10 CFR Part 50 licenses for nuclear reactors at

reactor sites under the general license issued pursuant to §72.210, 10 CFR

Part 72, subject to the conditions specified by §72.212 and the attached

Conditions for Cask Use.

9. Effective Date:

November 4, 1993

Expiration Date:

November 30, 2013

FOR THE NUCLEAR REGULATORY COMMISSION

oaSLj

Charles J. Haughrey, Chief (J1

Storage and Transport Systems Bral

Division of Industrial and

Material Nuclear Safety, NMSS

3
CONDITIONS FOR CASK USE

CERTIFICATE OF COMPLIANCE

72-1005
TABLE OF CONTENTS

Page

1.0 INTRODUCTION ......................................... A-1

1.1 General Conditions ........................................ A-1

1.2 Preoperational Conditions .... ............................. A-I

2.0 FUNCTIONAL AND OPERATING LIMITS ................................ A-3

2.1 Fuel To Be Stored At ISFSI .. .............................. A-3

2.2 TN-24 Dry Storage Cask .................................... A-4

2.3 Limiting Condition -- Handling Height .................. ... A-6

2.4 Dry Storage Cask Surface Contamination ........ ............ A-6

2.5 Dry Storage Cask Internal Cover Gas ......... .............. A-7

2.6 Impact Limiter ......................................... A-7

3.0 SURVEILLANCE REQUIREMENTS ...................................... A-8

3.1 Cask Seal Testing ......................................... A-9

3.2 Cask Contamination ............................. ........... A-9

3.3 Dose Rates ......................................... A-9

3.4 Safety Status Surveillance ...... .......................... A-10

3.5 Cask Interseal Pressure ................................... A-10

3.6 Alarm System ........................................ . A-11

TABLES

2-1 TN-24 Operating Limits .................................... A-5

3-1 Surveillance Requirements Summary ... ...................... A-8
1.0 INTRODUCTION

These Conditions for Cask Use govern the safety of the receipt, possession, and

storage of irradiated nuclear fuel at an Independent Spent Fuel Storage

Installation (ISFSI) and the transfer of such fuel between a Nuclear Power Station

and its ISFSI.

1.1 GENERAL CONDITIONS

1.1.1 Oerating Procedures

Written operating procedures shall be prepared for cask handling, movement,

emplacement, surveillance, and maintenance.

1.1.2 Ouality Assurance

Activities at the ISFSI shall be conducted in accordance with the requirements of

Appendix B, 10 CFR Part 50.

1.2 PREOPERATIONAL CONDITIONS

The user shall not allow the initial loading of spent nuclear fuel in the TN-24

cask until the following preoperational license conditions are satisfied:

(1) A training module shall be developed for the Station Training

Program establishing an ISFSI Training and Certification Program

which will cover the following:

a. Cask Design (overview)

b. ISFSI Facility Design (overview)

c. Certificate of Compliance Conditions (overview)

d. Fuel loading/unloading and cask handling procedures

e. Abnormal Event Procedures

A-1
(2) A training exercise (Dry Run) of cask loading and handling

activities shall be held which shall include but not be limited to:

a. Moving a cask in and out of spent fuel pool area.

b. Loading a fuel assembly (using dummy assembly).

c. Cask sealing and cover gas backfilling operations.

d. Moving cask to and placing it on the storage pad.

e. Returning the cask to the reactor spent fuel pool.

f. Unloading the cask assuming fuel cladding failure.

g. Cask decontamination.

A-2
2.0 FUNCTIONAL AND OPERATING LIMITS

2.1 FUEL TO BE STORED AT ISFSI

2.1.1 Specification

The spent nuclear fuel to be received and stored at the ISFSI in TN-24 casks shall

meet the following requirements:

(1) Only irradiated 14 x 14, 15 x 15, and 17 x 17 PWR fuel assemblies

with Zircaloy fuel rod cladding may be used. Total assemblies per

cask < 24.

(2) Maximum initial enrichment shall not exceed 3.5 weight percent

U-235 for fuel stored in the copper plated stainless steel basket,

which was reviewed and found acceptable.

(3) Maximum assembly average burnup shall not exceed 35,000 megawattdays per metric ton uranium and specific power shall not exceed

37.5 MW/MTU.

(4) Maximum heat generation rate shall not exceed 1.0 kilowatt per

fuel assembly.

(5) Fuel shall be intact, unconsolidated fuel. Partial fuel

assemblies, that is, fuel assemblies from which fuel pins are

missing must not be stored unless dummy fuel pins are used to

displace an amount of water equal to that displaced by the

original pins.

(6) Fuel assemblies known or suspected to have structural defects

sufficiently severe to adversely affect fuel handling and transfer

capability shall not be loaded into the cask for storage.

(7) A procedure shall be developed for the documentation of the

characterizations performed to select spent fuel to be stored in

A-3
the casks. Such procedure shall include independent verification

of fuel assembly selection by an individual other than the

original individual making the selection.

(8) Immediately prior to insertion of a spent fuel assembly into a

cask, the identity of the assembly shall be independently verified

by two individuals.

2.1.2 Basis

The design criteria and subsequent safety analysis assumed certain characteristics

and limitations for the fuels that are to be received and stored. Specification

2.1.1 ensures that these bases remain valid by defining the type of spent fuel,

maximum initial enrichment, irradiation history, and maximum thermal heat

generation.

2.2 TN-24 DRY STORAGE CASK

2.2.1 Specification

The TN-24 Dry Storage Casks used to store spent nuclear fuel at an ISFSI shall

have the operating limits shown in Table 2-1.

2.2.2 Basis

The design criteria and subsequent safety analysis of the TN-24 assumed certain

characteristics and operating limits for the use of the casks. This specification

ensures that those design criteria are not exceeded.

A-4
Table 2-1 TN-24 OPERATING LIMITS

Max. Lifting Height

without bottom impact limiter

Removable Contamination

* Beta and gamma

* Alpha

Dose Rate

* 2 m Distance

* Surface

Two Vacuum Drying Procedures

Initial Interseal Pressure

Initial Helium Helium Pressure (Cask Cavity)

Cask Tightness (at closure):

(Standard He-Leak Rate)

* Primary Cover Seal

* Pressure Monitoring System

Max. Specific Power of One Fuel Assembly

ODerating Limit

18 inches

< 2200 dis/min/100 cm2

< 220 dis/min/100 cm2

< 10 mrem/hr

< 200 mrem/hr

< 10 mBar (hold for 30 min.)

5.8 atmospheres + 5%

2.2 atmospheres + 5%

< 10-6 std cc/s

< 106 std cc/s

1.0 kW

A-5
2.3 LIMITING CONDITION - HANDLING HEIGHT

2.3.1. Specification

This specification applies to handling of a cask being used for spent fuel storage

outside of the Fuel Building and Crane Enclosure Building. The TN-24 dry storage

cask shall not be handled at a height greater than 18 inches without a bottom

impact limiter.

2.3.2 Basis

The drop analysis performed for the TN-24 dry storage casks for postulated cask

drop incidents on the ISFSI storage pad indicates that the fuel basket and cask

body have sufficient ductility and toughness to sustain a drop of 18 inches or

less without using an impact limiter without sustaining unacceptable damage to the

casks and fuel basket. This limiting condition ensures that the handling height

limits will not be exceeded at the storage pad or in transit to and from the

reactor.

2.4 DRY STORAGE CASK SURFACE CONTAMINATION

2 4.1 Specification

Initial removable contamination on the dry storage cask shall not exceed 2200

dis/min/100 cm2 from beta-gamma sources, and 220 dis/min/100 cm2 from alpha

sources.

2.4.2 Basis

Compliance with this limit ensures that the decontamination requirements of 49 CFR

173.443, will be met over the lifetime of the cask in storage.

A-6
2.5 DRY STORAGE CASK INTERNAL COVER GAS

2.5.1 Specification

The dry storage cask shall be backfilled with helium to 2.2 atmospheres + 5%.

2.5.2 Basis

The thermal analysis performed for the dry storage casks assumes the use of helium

as a cover gas. In addition, the use of an inert gas (helium) is to ensure longterm maintenance of fuel clad integrity.

2.6 IMPACT LIMITER

2.6.1 Secification

The dry storage cask shall have an upper impact limiter attached during transport

and storage. The cask shall not be lifted higher than 18 inches without a lower

impact limiter attached. The impact limiters shall be as described in the

following letters: E-10843 and E-10867 dated April 29, 1989, E-10929 dated

May 25, 1989, and E-10995 dated June 7, 1989.

2.6.2 Basis

The impact limiters will ensure that the cask is not damaged in the unlikely event

of a drop or tip over.

A-7
3.0 SURVEILLANCE REQUIREMENTS

Requirements for surveillance of various radiation levels, cask internal pressure,

contamination levels, cask seal leak rates, and fuel related parameters are

contained in this section. These requirements are summarized in Table 3-1 from

details contained in Section 3.1 through 3.6.

The specified frequency for each Surveillance Requirement is met if the

surveillance is performed within 1.25 times the interval specified in the

frequency, as measured from the previous performance. For frequencies specified

as once," the above interval extension does not apply. If a required action

requires performance of a surveillance or its completion time requires periodic

performance of once per...," the above frequency extension applies to the

repetitive portion, but not to the initial portion of the completion time.

Table 3-1 SURVEILLANCE REQUIREMENTS SUMMARY

Section Quantity or Item Period

3.1.1 Cask Seal Testing L

3.2.1 Cask Contamination L

3.3.1 Dose Rates

Cask surface or up to 2 meters from cask surface L

Fence Q

3.4.1 Safety Status Surveillance Q

3.5.1 Pressure Monitoring Device Parameters P & L

3.6.1 Alarm System A

P - Prior to cask loading

L - During loading operations

Q - Quarterly--At least once per 92 days

A - Annually--At least once per 366 days

A-8
3.1 CASK SEAL TESTING

3.1.1 SDecification

Prior to storage, the cask must be properly sealed and tested using a standard

helium leak test as specified in Section 10.2.2.1 of the TSAR. The initial leak

rate shall be less than of 106 std cc/sec.

3.1.2 Basis

The safety analysis of leak tightness of the cask as discussed in the topical

report is based on the seals after 20 years being leak tight to 10'6 std cc/s.

This check is done to ensure compliance with this design criteria.

3.2 CASK CONTAMINATION

3.2.1 Specification

After cask loading and prior to moving the cask to the storage pad, the cask shall

be surveyed to ensure that removable surface contamination levels are less than

2200 dis/min/100 cm2 from beta-gamma emitting sources, and 220 dis/min/100 cm2

from alpha emitting sources.

3.2.2 Basis

This surveillance requirement will ensure compliance with the decontamination

requirements of 49 CFR 173.443 during storage in the ISFSI.

3.3 DOSE RATES

3.3.1 Specification

The following dose rate measurements shall be made for the ISFSI:

(1) Cask Surface Gamma and Neutron Dose Rates: After completion of

cask loading, gamma and neutron measurements shall be taken on the

A-9
outside surface (or within 2 meters of the cask surface). The

combined gamma and neutron dose rates shall be less than the

surface dose rate stated in Table 2-1 (or the specified rate at a

distance of up to 2 meters from the cask surface).

(2) Dry Cask ISFSI Boundary: Doses shall be determined by measurement

at the Dry Cask ISFSI site fence and shall be evaluated on a

quarterly basis to demonstrate compliance with 10 CFR Part 20.

3.3.2 Basis

These measurements are necessary to assure compliance with the cask specifications

and that the dose rates at the security fence meet Part 20 limits as additional

casks are placed in storage.

3.4 SAFETY STATUS SURVEILLANCE

3.4.1 Specification

A visual surveillance of the ISFSI shall be performed on a quarterly basis to

determine that no significant damage or deterioration of the exterior of the casks

has occurred. Surveillance shall also include observation to determine that no

significant accumulation of debris on cask surfaces has occurred.

3.4.2 Basis

The surveillance requirements shall ensure cask maintenance.

3.5 CASK INTERSEAL PRESSURE

3.5.1 Specification

The cask confinement integrity shall be monitored by use of a pressure monitoring

device to verify the leak tightness of the cask. A functional test shall be

performed during cask preparation.

A-10
3.5.2. Basis

This specification requires the cask cavity atmosphere be maintained and monitored

to detect any possible leakage of cask seals.

3.6 ALARM SYSTEM

3.6.1 Secification

An alarm system to which all of the pressure monitoring devices are connected

shall be installed at the storage site and functionally tested annually to ensure

proper operation of the system.

3.6.2 Basis

The alarm system must be capable of alerting surveillance personnel of possible

cask seal failure and must permit identification of the specific cask indicating a

seal failure.

A-1l