24250 Federal Register / Vol. 61, No. 94 / Tuesday, May 14, 1996 / Proposed Rules

used that may even contradict or differ

from SER and COC requirements.

The petitioner has concluded that a

final SAR for a spent fuel dry storage

cask design should be accepted which

completely fulfills all NRC SER and

COC requirements before the cask is

certified. The petitioner also believes

that the NRC must address how the final

vendor SAR can be modified as needed

after a cask design is certified.

Currently, the only way an SAR can be

amended is through rulemaking. The

petitioner has also concluded that the

SAR revision number and date should

be required whenever that document is

referenced to eliminate confusion and

prevent a situation where an SAR does

not meet NRC SER and COC

requirements. Lastly, the petitioner is

concerned that the NRC is withholding

cask unloading procedures from the

public and recommends that the NRC

make these procedures publicly

available. The petitioner cites an

example of a faulty dry cask at the

Palisades facility where the licensee has

been waiting to have a final unloading

procedure approved by the NRC. The

petitioner has concluded that dry cask

storage issues should be addressed and

resolved by the NRC to set the proper

precedent for the national nuclear waste

disposal program.

Electronic Submission of Comments

Comments may be submitted

electronically, in either ASCII text or

WordPerfect format (version 5.1 or

later), by calling the NRC Electronic

Bulletin Board (BBS) on FedWorld. The

bulletin board may be accessed using a

personal computer, a modem, and one

of the commonly available

communications software packages, or

directly via Internet. Background

documents on this rulemaking are also

available for downloading and viewing

on the bulletin board.

If using a personal computer and

modem, the NRC rulemaking subsystem

on FedWorld can be accessed directly

by dialing the toll free number (800)

303–9672. Communication software

parameters should be set as follows:

parity to none, data bits to 8, and stop

bits to 1 (N,8,1). Using ANSI or VT–100

terminal emulation, the NRC

rulemaking subsystem can then be

accessed by selecting the ‘‘Rules Menu’’

option from the ‘‘NRC Main Menu.’’

Users will find the ‘‘FedWorld Online

User’s Guides’’ particularly helpful.

Many NRC subsystems and data bases

also have a ‘‘Help/Information Center’’

option that is tailored to the particular

subsystem.

The NRC subsystem on FedWorld can

also be accessed by a direct dial phone

number for the main FedWorld BBS,

(703) 321–3339, or by using Telnet via

Internet: fedworld.gov. If using (703)

321–3339 to contact FedWorld, the NRC

subsystem will be accessed from the

main FedWorld menu by selecting the

‘‘Regulatory, Government

Administration and State Systems,’’

then selecting ‘‘Regulatory Information

Mall.’’ At that point, a menu will be

displayed that has an option ‘‘U.S.

Nuclear Regulatory Commission’’ that

will take you to the NRC Online main

menu. The NRC Online area also can be

accessed directly by typing ‘‘/go nrc’’ at

a FedWorld command line. If you access

NRC from FedWorld’s main menu, you

may return to FedWorld by selecting the

‘‘Return to FedWorld’’ option from the

NRC Online Main Menu. However, if

you access NRC at FedWorld by using

NRC’s toll-free number, you will have

full access to all NRC systems, but you

will not have access to the main

FedWorld system.

If you contact FedWorld using Telnet,

you will see the NRC area and menus,

including the Rules Menu. Although

you will be able to download

documents and leave messages, you will

not be able to write comments or upload

files (comments). If you contact

FedWorld using FTP, all files can be

accessed and downloaded but uploads

are not allowed; all you will see is a list

of files without descriptions (normal

Gopher look). An index file listing all

files within a subdirectory, with

descriptions, is available. There is a 15-

minute time limit for FTP access.

Although FedWorld also can be

accessed through the World Wide Web,

like FTP, that mode only provides

access for downloading files and does

not display the NRC Rules Menu.

For more information on NRC bulletin

boards call Mr. Arthur Davis, Systems

Integration and Development Branch,

NRC, Washington, DC 20555, telephone

(301) 415–5780; e-mail AXD3@nrc.gov.

Dated at Rockville, Maryland, this 8th day

of May, 1996.

For the Nuclear Regulatory Commission.

John C. Hoyle,

Secretary of the Commission.

[FR Doc. 96–12027 Filed 5–13–96; 8:45 am]

BILLING CODE 7590–01–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96–NM–25–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 767 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

supersedure of an existing airworthiness

directive (AD), applicable to certain

Boeing Model 767 series airplanes, that

currently requires inspections to detect

cracking and corrosion of the aft

trunnion of the outer cylinder of the

main landing gear (MLG) and various

follow-on actions. That action also

provides for the optional termination of

the inspections by repairing the outer

cylinder and installing new aft trunnion

bushings. That AD was prompted by

reports of failure of several MLG due to

fractures of the aft trunnion outer

cylinders. The actions specified by that

AD are intended to prevent the collapse

of the MLG due to stress corrosion

cracking of the aft trunnion of the outer

cylinder. This proposed action would

require operators to implement the

previously optional terminating action.

DATES: Comments must be received by

June 24, 1996.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 96–NM–

25–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

Comments may be inspected at this

location between 9:00 a.m. and 3:00

p.m., Monday through Friday, except

Federal holidays.

The service information referenced in

the proposed rule may be obtained from

Boeing Commercial Airplane Group,

P.O. Box 3707, Seattle, Washington

98124–2207. This information may be

examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

James G. Rehrl, Aerospace Engineer,

Airframe Branch, ANM–120S, Seattle

Aircraft Certification Office, FAA,

Transport Airplane Directorate, 1601

Lind Avenue, SW., Renton, Washington

98055–4056; telephone (206) 227–2783;

fax (206) 227–1181.
Federal Register / Vol. 61, No. 94 / Tuesday, May 14, 1996 / Proposed Rules 24251

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to

participate in the making of the

proposed rule by submitting such

written data, views, or arguments as

they may desire. Communications shall

identify the Rules Docket number and

be submitted in triplicate to the address

specified above. All communications

received on or before the closing date

for comments, specified above, will be

considered before taking action on the

proposed rule. The proposals contained

in this notice may be changed in light

of the comments received.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the proposed rule. All comments

submitted will be available, both before

and after the closing date for comments,

in the Rules Docket for examination by

interested persons. A report

summarizing each FAA-public contact

concerned with the substance of this

proposal will be filed in the Rules

Docket.

Commenters wishing the FAA to

acknowledge receipt of their comments

submitted in response to this notice

must submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 96–NM–25–AD.’’ The

postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this

NPRM by submitting a request to the

FAA, Transport Airplane Directorate,

ANM–103, Attention: Rules Docket No.

96–NM–25–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

On February 22, 1996, the FAA issued

AD 96–03–02 R1, amendment 39–9526

(61 FR 7694, February 29, 1996). [AD

96–03–02 R1 was issued as a correction

to AD 96–03–02, amendment 39–9497

(61 FR 3652, February 1, 1996)]. That

AD is applicable to certain Boeing

Model 767 series airplanes, which

requires various inspections to detect

cracking and corrosion of the aft

trunnion and various follow-on actions.

That action was prompted by reports of

failure of several main landing gears

(MLG) due to fracture of the aft trunnion

outer cylinder. The requirements of that

AD are intended to prevent the collapse

of the MLG due to stress corrosion

cracking of the aft trunnion of the outer

cylinder.

That AD also provided for an optional

action which, if accomplished, would

constitute terminating action for the

required inspections. In the preamble of

that AD, the FAA indicated that this

optional action, consisting of repair of

the outer cylinder and replacement of

the existing bushings with new

bushings, was considered ‘‘interim

action’’ and that further rulemaking

action to mandate the repair and

replacement was being considered. The

FAA also indicated that the proposed

compliance time for the replacement

was sufficiently long so that notice and

public comment were practicable. As a

follow-on action from that

determination, the FAA is now

proposing to mandate the previously

optional repair and replacement.

Explanation of Relevant Service

Information

The FAA has previously reviewed

and approved Boeing Alert Service

Bulletin 767–32A0148, dated December

21, 1995, which describes procedures

for repair of the outer cylinder and

replacement of the existing bushings of

the aft trunnion and crossbolt of the

MLG with new bushings.

Accomplishment of this repair and

replacement eliminates the need for

certain follow-on actions that are

described in Boeing Service Bulletin

767–32A0151, dated November 30,

1995, which was referenced in AD 96–

03–02 R1 as the appropriate source of

service information.

FAA’s Conclusions

The FAA has determined that

accomplishment of the repair and

replacement specified in Boeing Alert

Service Bulletin 767–32A0148 will

positively address the unsafe condition

identified as the failure of the MLG due

to stress corrosion cracking of the aft

trunnion of the outer cylinder.

Explanation of the Proposed Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other products of this same

type design, the proposed AD would

supersede AD 96–03–02 R1. It would

continue to require various inspections

to detect cracking and corrosion of the

aft trunnion of the outer cylinder of the

MLG, and require various follow-on

actions. The proposed AD also would

require repair of the outer cylinder and

replacement of the bushings in the aft

trunnion and crossbolt of the MLG with

new bushings. Accomplishment of the

repair and replacement would

constitute terminating action for the

requirements of the AD.

Accomplishment of the repair and

replacement also would terminate the

requirements of the following AD’s:

• AD 95–19–10, amendment 39–9372

(60 FR 47689, September 14, 1995), and

• AD 95–20–51, amendment 39–9398

(60 FR 53109, October 12, 1995). [The

comment period for AD 95–20–51 was

extended by an AD action that was

issued on November 28, 1995 (60 FR

62321, December 6, 1995.)]

Differences Between the Proposed AD

and Relevant Service Information

Operators should note that Boeing

Alert Service Bulletin 767–32A0148

refers to Component Maintenance

Manual (CMM) 32–11–40, which, in

turn, provides instructions for plugging

the aft trunnion lubrication fitting with

a rivet. This proposed AD, however,

does not require plugging that fitting to

terminate the requirements of this

proposed AD, AD 95–19–10, or AD 95–

20–51.

Cost Impact

There are approximately 609 Boeing

Model 767 series airplanes of the

affected design in the worldwide fleet.

The FAA estimates that 204 airplanes of

U.S. registry would be affected by this

proposed AD.

The actions that are currently

required by AD 96–03–02 R1, and

retained in this AD, take approximately

34 work hours per airplane to

accomplish, at an average labor rate of

$60 per work hour. Based on these

figures, the cost impact on U.S.

operators of the actions currently

required is estimated to be $416,160, or

$2,040 per airplane.

The new actions that are proposed in

this AD action would take

approximately 218 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour.

Required parts would cost

approximately $9,510 per airplane.

Based on these figures, the cost impact

on U.S. operators of the proposed

requirements of this AD is estimated to

be $4,608,360 or $22,590 per airplane.

The cost impact figures discussed

above are based on assumptions that no

operator has yet accomplished any of

the current or proposed requirements of

this AD action, and that no operator

would accomplish those actions in the

future if this AD were not adopted.

Regulatory Impact

The regulations proposed herein

would not have substantial direct effects

on the States, on the relationship

between the national government and

the States, or on the distribution of

power and responsibilities among the

various levels of government. Therefore,

in accordance with Executive Order

12612, it is determined that this
24252 Federal Register / Vol. 61, No. 94 / Tuesday, May 14, 1996 / Proposed Rules

proposal would not have sufficient

federalism implications to warrant the

preparation of a Federalism Assessment.

For the reasons discussed above, I

certify that this proposed regulation (1)

is not a ‘‘significant regulatory action’’

under Executive Order 12866; (2) is not

a ‘‘significant rule’’ under the DOT

Regulatory Policies and Procedures (44

FR 11034, February 26, 1979); and (3) if

promulgated, will not have a significant

economic impact, positive or negative,

on a substantial number of small entities

under the criteria of the Regulatory

Flexibility Act. A copy of the draft

regulatory evaluation prepared for this

action is contained in the Rules Docket.

A copy of it may be obtained by

contacting the Rules Docket at the

location provided under the caption

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration proposes to amend part

39 of the Federal Aviation Regulations

(14 CFR part 39) as follows:

PART 39—AIRWORTHINESS

DIRECTIVES

1. The authority citation for part 39

continues to read as follows:

Authority: 49 USC 106(g), 40113, 44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

removing amendment 39–9526 (61 FR

7694, February 29, 1996), and by adding

a new airworthiness directive (AD), to

read as follows:

Boeing: Docket 96–NM–25–AD.

Supersedes AD 96–03–02 R1,

Amendment 39–9526.

Applicability: Model 767 series airplanes

having line numbers 001 through 609, on

which the terminating action described in

paragraph (e) of this AD has not been

accomplished; certificated in any category.

Note 1: This AD applies to each airplane

identified in the preceding applicability

provision, regardless of whether it has been

otherwise modified, altered, or repaired in

the area subject to the requirements of this

AD. For airplanes that have been modified,

altered, or repaired so that the performance

of the requirements of this AD is affected, the

owner/operator must request approval for an

alternative method of compliance in

accordance with paragraph (h) of this AD.

The request should include an assessment of

the effect of the modification, alteration, or

repair on the unsafe condition addressed by

this AD; and, if the unsafe condition has not

been eliminated, the request should include

specific proposed actions to address it.

Compliance: Required as indicated, unless

accomplished previously.

To prevent the collapse of the main

landing gear (MLG) due to stress corrosion

cracking of the aft trunnion of the outer

cylinder, accomplish the following:

(a) Perform the inspections described in

paragraph III, Accomplishment Instructions,

of Boeing Alert Service Bulletin 767–

32A0151, dated November 30, 1995, to detect

cracking and corrosion of the aft trunnion of

the outer cylinder of the MLG at the time

specified in paragraph (a)(1), (a)(2), or (a)(3)

of this AD, as applicable. These inspections

are to be accomplished in accordance with

Figure 1 of that alert service bulletin. Repeat

these inspections thereafter at the intervals

specified in that alert service bulletin. To

determine the category in which an airplane

falls, the age of the outer cylinder of the MLG

is to be calculated as of February 16, 1996,

(the effective date of AD 96–03–02 R1,

amendment 39–9526). For airplanes on

which the age of the right MLG differs from

the age of the left MLG, an operator may

place the airplane into a category that is the

higher (numerically) of the two categories to

ease its administrative burden, and to

simplify the recordkeeping requirements

imposed by this AD. Once the category into

which an airplane falls is determined,

operators must obtain approval from the

Manager, Seattle Aircraft Certification Office

(ACO), FAA, Transport Airplane Directorate,

to move that airplane into another category.

Note 2: The broken (dash) lines used in

Figure 1 of Boeing Alert Service Bulletin

767–32A0151, dated November 30, 1995,

denote ‘‘go to’’ actions for findings of

discrepancies detected during any of the

inspections required by this AD.

Note 3: Boeing Alert Service Bulletin 767–

32A0151, dated November 30, 1995, refers to

Boeing Alert Service Bulletin 767–32A0148,

dated December 21, 1995, for procedures to

repair the outer cylinder and replace the

bushings in the outer cylinder of the MLG

with new bushings.

(1) For airplanes identified as Category 3 in

paragraph I.C. of Boeing Alert Service

Bulletin 767–32A0151, dated November 30,

1995: Perform the initial inspections within

30 days after February 16, 1996 (the effective

date of AD 96–03–02 R1, amendment 39–

9526).

(2) For airplanes identified as Category 2 in

paragraph I.C. of Boeing Alert Service

Bulletin 767–32A0151, dated November 30,

1995: Perform the initial inspections within

90 days after February 16, 1996, (the effective

date of AD 96–03–02 R1, amendment 39–

9526).

(3) For airplanes identified as Category 1 in

paragraph I.C. of Boeing Alert Service

Bulletin 767–32A0151, dated November 30,

1995: Perform the initial inspections prior to

the accumulation of 21⁄2 years since the MLG

outer cylinder was new or last overhauled, or

within 150 days after February 16, 1996, (the

effective date of AD 96–03–02 R1,

amendment 39–9526), whichever occurs

later.

(b) If no cracking or corrosion is detected,

accomplish the follow-on actions described

in the Boeing Alert Service Bulletin 767–

32A0151, November 30, 1995, at the time

specified in the alert service bulletin. These

follow-on actions are to be accomplished in

accordance with that alert service bulletin.

(c) If any cracking is detected, prior to

further flight, replace the outer cylinder with

a new or serviceable outer cylinder in

accordance with Boeing Alert Service

Bulletin 767–32A0151, dated November 30,

1995.

(d) If any corrosion is detected, accomplish

the follow-on actions at the time specified in

the ‘‘Corrosion Flowchart,’’ in Figure 1 of

Boeing Alert Service Bulletin 767–32A0151,

dated November 30, 1995. The follow-on

actions are to be accomplished in accordance

with that alert service bulletin.

(e) Repair the outer cylinder and replace

the bushings in the aft trunnion and crossbolt

of the MLG with new bushings, in

accordance with Boeing Alert Service

Bulletin 767–32A0148, dated December 21,

1995, at the time specified in either

paragraph (e)(1) or (e)(2), as applicable.

Accomplishment of this repair and

replacement constitutes terminating action

for this AD, and for the requirements of AD

95–19–10, amendment 39–9372; and AD 95–

20–51, amendment 39–9398.

Note 4: Boeing Alert Service Bulletin 767–

32A0148 refers to Component Maintenance

Manual (CMM) 32–11–40 for certain

procedures. Operators should note that,

although the CMM specifies plugging the aft

trunnion lubrication fitting with a rivet, this

AD does not require this action to be

accomplished in order to terminate the

requirements of this AD, AD 95–19–10, or

AD 95–20–51. Plugging the aft trunnion

lubrication fitting with a rivet is the

operator’s prerogative.

(1) For airplanes identified as Category 3 in

paragraph I.C. of Boeing Alert Service

Bulletin 767–32A0151, dated November 30,

1995: Accomplish the repair and replacement

prior to the accumulation of 5 and years

since the MLG outer cylinders were new or

last overhauled, or within 18 months after

the effective date of this AD, whichever

occurs later.

(2) For airplanes identified as either

Category 1 or Category 2 in paragraph I.C. of

Boeing Alert Service Bulletin 767–32A0151,

dated November 30, 1995, accomplish the

repair and replacement at the time specified

in either paragraph (e)(2)(i) or (e)(2)(ii) of this

AD:

(i) Prior to the accumulation of 5 and 1/2

years since the MLG outer cylinders were

new or last overhauled, or within 18 months

after the effective date of this AD, whichever

occurs later. Or,

(ii) Prior to the accumulation of 7 years

since the MLG outer cylinders were new or

last overhauled, provided that

accomplishment of visual and nondestructive testing (NDT) inspections at the

times specified in Figure 1 of the

Accomplishment Instructions of Boeing Alert

Service Bulletin 767–32A0151, dated

November 30, 1995, are repeated until the

repair and replacement are accomplished.

(g) Accomplishment of the inspection

requirements of this AD [in accordance with

Boeing Alert Service Bulletin 767–32A0151,
Federal Register / Vol. 61, No. 94 / Tuesday, May 14, 1996 / Proposed Rules 24253

dated November 30, 1995] is considered

acceptable for compliance with AD 95–19–

10, amendment 39–9372; and AD 95–20–51,

amendment 39–9398.

(h)(1) An alternative method of compliance

or adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager, Seattle

ACO. Operators shall submit their requests

through an appropriate FAA Principal

Maintenance Inspector, who may add

comments and then send it to the Manager,

Seattle ACO.

Note 5: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle ACO.

(2) Alternative methods of compliance,

approved in accordance with AD 96–03–02,

amendment 39–9497; or AD 93–03–02 R1,

amendment 39–9526; are approved as

alternative methods of compliance with this

AD.

(i) Special flight permits may be issued in

accordance with sections 21.197 and 21.199

of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the airplane to

a location where the requirements of this AD

can be accomplished.

Issued in Renton, Washington, on May 8,

1996.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 96–12021 Filed 5–13–96; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF HEALTH AND

HUMAN SERVICES

Food and Drug Administration

21 CFR Part 589

[Docket No. 96N–0135]

RIN 0910–AA91

Substances Prohibited From Use in

Animal Food or Feed; Protein Derived

From Ruminants Prohibited in

Ruminant Feed

AGENCY: Food and Drug Administration,

HHS.

ACTION: Advance notice of proposed

rulemaking.

SUMMARY: The Food and Drug

Administration (FDA) is soliciting

comments on the issue of using protein

derived from ruminants (e.g., cattle,

sheep, goats, mule deer, and elk) in

ruminant feed. Animal feed containing

protein derived from ruminants may

contain the disease agent that causes

transmissible spongiform

encephalopathy (TSE) in animals.

Epidemiological evidence gathered in

the United Kingdom (U.K.) suggests a

link between an outbreak of ruminant

TSE, specifically bovine spongiform

encephalopathy (BSE) and feeding

animals protein derived from

ruminants. In addition information from

the U.K. also suggests that exposure to

BSE may explain some of the recent

cases of variant Creutzfeldt-Jakob

disease (v-CJD) in the U.K. This action

is being taken to protect the health of

animals and to reduce any risk which

might be faced by humans. FDA is

requesting scientific and economic

information and other comments

relating to the prohibition of ruminant

protein in ruminant feed.

DATES: Written comments by June 13,

1996.

ADDRESSES: Submit written comments

to the Dockets Management Branch

(HFA–305), Food and Drug

Administration, 12420 Parklawn Dr.,

rm. 1–23, Rockville, MD 20857.

FOR FURTHER INFORMATION CONTACT:

George Graber, Center For Veterinary

Medicine (HFV–220), Food and Drug

Administration, 7500 Standish Pl.,

Rockville, MD 20855, 301–594–1724.

SUPPLEMENTARY INFORMATION:

I. Background

In the Federal Register of August 29,

1994 (59 FR 44584) FDA issued a

proposed rule declaring that specified

offal from adult (more than 12 months

of age) sheep and goats is not generally

recognized as safe for use in ruminant

feed and is an unapproved food additive

when added to ruminant feed. The

proposed rule defined ‘‘specified offal’’

as any tissue from the brain, spinal cord,

spleen, thymus, tonsil, lymph nodes, or

intestines of sheep or goats, or any

processed product that is reasonably

expected to contain specified offal.

Processed products that may contain

specified offal include, but are not

limited to, meat meal, meat and bone

meal, animal byproduct meal, meat

byproducts, glandular meal, and cooked

bone meal. Accordingly, in the absence

of an approved food additive regulation

or investigational exemption, the use in

ruminant feed of ingredients containing

specified offal from adult sheep or goats

would cause the feeds to be considered

adulterated within the meaning of the

Federal Food, Drug, and Cosmetic Act

(the act). FDA proposed the action

because the specified offal may contain

the agent that causes scrapie, a TSE of

sheep and goats. Since the proposal was

issued, the agency has been evaluating

the comments submitted on the

proposal, monitoring the scientific

advances made in understanding the

interrelationships among the animal

TSE’s, and participating in a number of

national and international task force/

symposia to better understand the BSE

epidemic. The actions that would have

been prohibited in the proposed rule are

considered in this advance notice of

proposed rulemaking. If it is determined

that some action is necessary, the

agency believes issuing an advance

notice of proposed rulemaking

(ANPRM) will hasten that process.

In the U. K., scrapie has been

epidemiologically associated with the

occurrence of BSE, another form of TSE.

The initial cases of BSE may have been

the result of feeding supplements to

cattle that were contaminated with

prions from scrapie-infected sheep offal.

Prions are highly resistant to procedures

that modify or destroy nucleic acids.

(Refs. 1 and 2). Prions are believed by

many scientists to be the agents

responsible for TSE’s, and they appear

to be modified forms of normal proteins.

BSE has been diagnosed in over

155,600 head of cattle from almost

33,000 herds in the U.K. No cases of

BSE have been diagnosed in the United

States. BSE is postulated to have been

spread in the U.K. among cattle by the

feeding of processed ruminant protein

to cattle. A July 1988 U.K. ban on this

feeding practice has resulted in a steady

reduction in the number of cases of BSE

detected in cattle, with the new cases

occurring mainly in animals born before

the ban was fully implemented.

Ten cases of CJD have been identified

in the U.K. in recent months with a new

neuropathological profile. Other

consistent features that are unusual

include the young age of the cases (16

to 39 years old at onset of clinical signs),

clinical findings, and the absence of the

electroencephalogram features typical

for CJD. Similar cases have not been

identified in other countries in the

European surveillance system. These 10

cases appear to represent a new variant

of CJD (v-CJD), which may be unique to

the U.K. The appearance of these 10

cases of v-CJD raises the possibility that

they are causally linked to BSE.

Although this may be the most plausible

explanation for these cases, a link with

BSE cannot be confirmed on the basis of

this evidence alone. (Ref. 3). Sporadic

occurrences of spongiform

encephalopathy in humans are known

to occur at a rate of 1 to 2 per million

population worldwide. A group of

international experts convened in April

1996 by the World Health Organization

concluded that there is no definite link

between BSE and v-CJD, but that

circumstantial evidence suggests

exposure to BSE may be the most likely

explanation. Among other

recommendations, the group

recommended that all countries should