Tennessee Valley Authority; Notice of Consideration of Issuance of Amendment To Facility Operating License, Proposed No Significant Hazards Consideration Determination, and Opportunity for a Hearing

NUCLEAR REGULATORY COMMISSION

[Docket No. 50-390]

Tennessee Valley Authority; Notice of Consideration of Issuance

of Amendment To Facility Operating License, Proposed No Significant

Hazards Consideration Determination, and Opportunity for a Hearing

The U.S. Nuclear Regulatory Commission (the Commission) is

considering issuance of an amendment to Facility Operating License No.

NPF-90, issued to the Tennessee Valley Authority (TVA or the licensee)

for operation of the Watts Bar Nuclear Plant (WBN), Unit 1 located in

Rhea County, Tennessee.

WBN currently has two containment hydrogen ignitors that are

inoperable due to an apparent fault in the common circuit supplying

these ignitors. This condition renders Train A of the WBN

[[Page 25244]]

hydrogen mitigation system (HMS) inoperable in accordance with TS

limiting condition for operation (LCO) 3.6.8. The condition was

discovered during routine surveillance testing to the Train A ignitors

on April 3, 1998, at which time WBN entered Condition A of limiting

condition for operation (LCO) 3.6.8. The ignitors are located in a very

high radiation and temperature area of lower containment and cannot be

repaired until the reactor is taken offline. WBN's next scheduled

outage for refueling is in February 1999. The proposed amendment would

revise the TS LCO 3.6.8 to provide temporary requirements for hydrogen

ignitors to address the two Train A ignitors which are currently out of

service. The revision would apply until the next shutdown to MODE 3

following which time ignitor repairs would be performed to restore the

HMS to an operable status.

Before issuance of the proposed license amendment, the Commission

will have made findings required by the Atomic Energy Act of 1954, as

amended (the Act) and the Commission's regulations.

The Commission has made a proposed determination that the amendment

request involves no significant hazards consideration. Under the

Commission's regulations in 10 CFR 50.92, this means that operation of

the facility in accordance with the proposed amendment would not (1)

involve a significant increase in the probability or consequences of an

accident previously evaluated; or (2) create the possibility of a new

or different kind of accident from any accident previously evaluated;

or (3) involve a significant reduction in a margin of safety. As

required by 10 CFR 50.91(a), the licensee has provided its analysis of

the issue of no significant hazards consideration, which is presented

below:

TVA has concluded that operation of WBN in accordance with the

proposed change to the TS does not involve a significant hazards

consideration. TVA's conclusion is based on its evaluation in

accordance with 10 CFR 50.91(a)(1) of the three standards set forth

in 10 CFR 50.92(c).

(A) The proposed amendment does not involve a significant

increase in the probability or consequences of an accident

previously evaluated.

The proposed temporary technical specification would permit two

specific Train A ignitors (30A and 31A) in non-adjacent regions to

be out of service until the next WBN entry into MODE 3. In this

condition, the remaining 32 of 34 ignitors, in combination with

thorough containment air mixing and with the hydrogen collection

function of the air return system, will maintain the ability to burn

hydrogen such that containment hydrogen remains low following a

degraded core accident. Thus, the design basis of the HMS will be

maintained such that a controlled hydrogen burn may occur at the

lower flammability concentration following a degraded core accident.

In addition, although a loss of Train B power could result in loss

of ignitors in two regions of lower containment, the short duration

allowed by the proposed amendment for this condition (not to exceed

72 hours) minimizes the likelihood of a concurrent accident

requiring the ignitors. The WBN PSA [probabilistic safety

assessment] establishes a probability of 3.6 x 10-7

events per reactor-year of a degraded core event based on 72 hours,

with the probability more remote for an accident that would generate

hydrogen in amounts equivalent to a metal-water reaction of 75% of

core cladding for which the HMS is intended. Additionally,

sufficient ignition capability in adjacent regions combined with

containment air mixing would provide capability by flame propagation

to the regions with no operable ignitors. Thus the failure of the

two specific ignitors should not result in any change to the post-

accident hydrogen burn profiles. Since the hydrogen concentration

would remain low and pocketing which could lead to rapid burns and

challenge containment is unlikely, the original design continues to

be met. Thus the probability of a containment failure and associated

radiological release is insignificantly altered. Because the

containment response will not change, the proposed TS will not

result in an increase in the probability or consequences of any

accident previously evaluated in the WBN FSAR.

(B) Operation of the facility in accordance with the proposed

amendment would not create the possibility of a new or different

kind of accident from any accident previously evaluated.

As discussed above, with the two Train A ignitors out of

service, the remaining 32 of 34 ignitors in combination with

containment air mixing will maintain the design basis of the HMS

such that a controlled hydrogen burn may be accomplished following a

degraded core accident, including a short time period of 72 hours

for which a loss of Train B power could result in loss of ignitors

in two regions of lower containment. Since the failure of the

ignitors should not result in any change to the post-accident

hydrogen burn profiles and because the containment response will not

change, the proposed TS will not result in any new or different kind

of accident from any accident previously evaluated.

(C) Operation of the facility in accordance with the proposed

amendment would not involve a significant reduction in margin of

safety.

Although the HMS is not provided for a design basis accident

(DBA), the Bases of the WBN TS define the design function of the HMS

as having the capability to burn hydrogen in a controlled manner at

the lower flammability concentration following a degraded core

accident. An ignitor train is currently considered OPERABLE with at

least 33 of 34 ignitors in service and each containment region

having at least one operable ignitor. Although the proposed TS

change would allow two specific Train A ignitors to be out of

service and their associated containment regions to be without any

ignitors for a short duration (72 hours), the remaining 32 of 34

ignitors will maintain the design basis of the HMS such that a

controlled hydrogen burn may be accomplished following a degraded

core accident. Although small increases in the hydrogen flammability

concentration may occur, deflagration would still be expected to

occur in a controlled manner and prior to a high hydrogen

concentration. As stated earlier, failure of the two ignitors should

not result in any change to the post-accident hydrogen burn profiles

or containment response. Therefore, the proposed TS change will not

involve a significant reduction in the margin of safety.

The NRC staff has reviewed the licensee's analysis and, based on

this review, it appears that the three standards of 10 CFR 50.92(c) are

satisfied. Therefore, the NRC staff proposes to determine that the

amendment request involves no significant hazards consideration.

The Commission is seeking public comments on this proposed

determination. Any comments received within 30 days after the date of

publication of this notice will be considered in making any final

determination.

Normally, the Commission will not issue the amendment until the

expiration of the 30-day notice period. However, should circumstances

change during the notice period such that failure to act in a timely

way would result, for example, in derating or shutdown of the facility,

the Commission may issue the license amendment before the expiration of

the 30-day notice period, provided that its final determination is that

the amendment involves no significant hazards consideration. The final

determination will consider all public and State comments received.

Should the Commission take this action, it will publish in the Federal

Register a notice of issuance and provide for opportunity for a hearing

after issuance. The Commission expects that the need to take this

action will occur very infrequently.

Written comments may be submitted by mail to the Chief, Rules and

Directives Branch, Division of Administrative Services, Office of

Administration, U.S. Nuclear Regulatory Commission, Washington, DC

20555-0001, and should cite the publication date and page number of

this Federal Register notice. Written comments may also be delivered to

Room 6D59, Two White Flint North, 11545 Rockville Pike, Rockville,

Maryland, from 7:30 a.m. to 4:15 p.m. Federal workdays.

[[Page 25245]]

Copies of written comments received may be examined at the NRC Public

Document Room, the Gelman Building, 2120 L Street, NW., Washington, DC.

The filing of requests for hearing and petitions for leave to intervene

is discussed below.

By June 8, 1998, the licensee may file a request for a hearing with

respect to issuance of the amendment to the subject facility operating

license and any person whose interest may be affected by this

proceeding and who wishes to participate as a party in the proceeding

must file a written request for a hearing and a petition for leave to

intervene. Requests for a hearing and a petition for leave to intervene

shall be filed in accordance with the Commission's ``Rules of Practice

for Domestic Licensing Proceedings'' in 10 CFR Part 2. Interested

persons should consult a current copy of 10 CFR 2.714 which is

available at the Commission's Public Document Room, the Gelman

Building, 2120 L Street, NW., Washington, DC, and at the local public

document room located at the Chattanooga-Hamilton County Library, 1001

Broad Street, Chattanooga, Tennessee 37402. If a request for a hearing

or petition for leave to intervene is filed by the above date, the

Commission or an Atomic Safety and Licensing Board, designated by the

Commission or by the Chairman of the Atomic Safety and Licensing Board

Panel, will rule on the request and/or petition; and the Secretary or

the designated Atomic Safety and Licensing Board will issue a notice of

hearing or an appropriate order.

As required by 10 CFR 2.714, a petition for leave to intervene

shall set forth with particularity the interest of the petitioner in

the proceeding, and how that interest may be affected by the results of

the proceeding. The petition should specifically explain the reasons

why intervention should be permitted with particular reference to the

following factors: (1) The nature of the petitioner's right under the

Act to be made party to the proceeding; (2) the nature and extent of

the petitioner's property, financial, or other interest in the

proceeding; and (3) the possible effect of any order which may be

entered in the proceeding on the petitioner's interest. The petition

should also identify the specific aspect(s) of the subject matter of

the proceeding as to which petitioner wishes to intervene. Any person

who has filed a petition for leave to intervene or who has been

admitted as a party may amend the petition without requesting leave of

the Board up to 15 days prior to the first prehearing conference

scheduled in the proceeding, but such an amended petition must satisfy

the specificity requirements described above.

Not later than 15 days prior to the first prehearing conference

scheduled in the proceeding, a petitioner shall file a supplement to

the petition to intervene which must include a list of the contentions

which are sought to be litigated in the matter. Each contention must

consist of a specific statement of the issue of law or fact to be

raised or controverted. In addition, the petitioner shall provide a

brief explanation of the bases of the contention and a concise

statement of the alleged facts or expert opinion which support the

contention and on which the petitioner intends to rely in proving the

contention at the hearing. The petitioner must also provide references

to those specific sources and documents of which the petitioner is

aware and on which the petitioner intends to rely to establish those

facts or expert opinion. Petitioner must provide sufficient information

to show that a genuine dispute exists with the applicant on a material

issue of law or fact. Contentions shall be limited to matters within

the scope of the amendment under consideration. The contention must be

one which, if proven, would entitle the petitioner to relief. A

petitioner who fails to file such a supplement which satisfies these

requirements with respect to at least one contention will not be

permitted to participate as a party.

Those permitted to intervene become parties to the proceeding,

subject to any limitations in the order granting leave to intervene,

and have the opportunity to participate fully in the conduct of the

hearing, including the opportunity to present evidence and cross-

examine witnesses.

If a hearing is requested, the Commission will make a final

determination on the issue of no significant hazards consideration. The

final determination will serve to decide when the hearing is held.

If the final determination is that the amendment request involves

no significant hazards consideration, the Commission may issue the

amendment and make it immediately effective, notwithstanding the

request for a hearing. Any hearing held would take place after issuance

of the amendment.

If the final determination is that the amendment request involves a

significant hazards consideration, any hearing held would take place

before the issuance of any amendment.

A request for a hearing or a petition for leave to intervene must

be filed with the Secretary of the Commission, U.S. Nuclear Regulatory

Commission, Washington, DC 20555-0001, Attention: Rulemakings and

Adjudications Staff, or may be delivered to the Commission's Public

Document Room, the Gelman Building, 2120 L Street, NW., Washington, DC,

by the above date. A copy of the petition should also be sent to the

Office of the General Counsel, U.S. Nuclear Regulatory Commission,

Washington, DC 20555-0001, and to General Counsel, Tennessee Valley

Authority, ET 10H, 400 East Summit Hill Drive, Knoxville, Tennessee

37902, attorney for the licensee.

Nontimely filings of petitions for leave to intervene, amended

petitions, supplemental petitions and/or requests for hearing will not

be entertained absent a determination by the Commission, the presiding

officer or the presiding Atomic Safety and Licensing Board that the

petition and/or request should be granted based upon a balancing of the

factors specified in 10 CFR 2.714(a)(1)(i)-(v) and 2.714(d).

For further details with respect to this action, see the

application for amendment dated April 29, 1998, which is available for

public inspection at the Commission's Public Document Room, the Gelman

Building, 2120 L Street, NW., Washington, DC, and at the local public

document room located at the Chattanooga-Hamilton County Library, 1001

Broad Street, Chattanooga, Tennessee.

Dated at Rockville, Maryland, this 1st day of May 1998.

For the Nuclear Regulatory Commission

Robert E. Martin,

Project Manager, Project Directorate II-3 , Division of Reactor

Projects--I/II, Office of Nuclear Reactor Regulation.

[FR Doc. 98-12179 Filed 5-6-98; 8:45 am]

BILLING CODE 7590-01-P