Northeast Nuclear Energy Company; 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. 50-423]

Northeast Nuclear Energy Company; 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-49 issued to Northeast Nuclear Energy Company (the licensee) for

operation of Millstone Nuclear Power Station, Unit 3, located in New

London County, Connecticut. The proposed change to Technical

Specification (TS) 3/4.4.4, Relief Valves, would ensure that the Power-

Operated Relief Valves (PORVs) will be capable of automatic cycling as

well as manual cycling when in the TS 3/4.4.4 action statements that

allow indefinite continued operation. The proposed amendment also makes

an editorial change, adds PORV surveillance requirements, and modifies

the associated Bases section. The proposed changes provide added

assurance that the pressurizer safety relief valves will not be damaged

due to water relief during an inadvertent safety injection event.

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:

NNECO has reviewed the proposed revision in accordance with

10CFR50.92 and has concluded that the revision does not involve a

significant hazards consideration (SHC). The basis for this

conclusion is that the three criteria of 10CFR50.92(c) are not

satisfied. The proposed revision does not involve [an] SHC because

the revision would not:

1. Involve a significant increase in the probability or

consequence of an accident previously evaluated.

Currently, timely operator action is required to prevent the

pressurizer from filling and potentially challenging the pressurizer

safety valves under water relief. The proposed TS changes provide

added assurance that the safety valves will not be challenged by

requiring the PORVs to be available for automatic pressure control.

The changes to the Surveillance Requirements add the appropriate

requirements to provide assurance that the automatic capability of

the PORVs is OPERABLE. The quarterly analog channel operational test

for the PORV high pressurizer pressure channels will not include

valve operation. However, it does involve changing the opening logic

from 2/4 to 1/3 and, thus, performing the surveillance increases the

probability of the PORVs opening inadvertently. If the automatic

capability of one PORV is INOPERABLE for more than 72 hours,

shutdown is required. If the automatic capability of both PORVs is

INOPERABLE for more than one hour, shutdown is required. If the

block valves have been closed but the automatic capability of the

PORVs is OPERABLE, an EOP [emergency operating procedure] change has

been made to assure that the PORV block valve would be opened within

ten minutes of an Inadvertent ECCS [emergency core cooling system]

actuation at power. The new analysis shows that this is sufficient

to assure that the PORVs would control RCS [reactor coolant system]

pressure if water relief is experienced and the safety valves would

not be challenged. Thus, it is concluded that the change provides

added assurance that the safety valves would not fail due to water

discharge.

Evaluations and analysis have been performed to demonstrate that

the PORVs and the associated piping are qualified for water relief

from an Inadvertent ECCS Actuation at Power Operation for one hour

from event initiation. This provides significant margin for operator

action to terminate the event.

The PORV control logic has been upgraded to be safety grade and

single failure proof. A 2/4 logic is used for opening and 3/4 logic

is used for subsequent closure. With the upgrade of the PORV control

logic, there is added assurance that the PORV will be capable of

providing automatic pressure control and preventing challenges to

the safety valves, particularly under water solid conditions.

However, there is a small impact on the probability of inadvertent

opening of both PORVs resulting from multiple channel failures. With

the new safety grade PORV control logic, two failed high pressurizer

pressure channels will result in inadvertent opening of both PORVs.

With the current logic, a single failed high pressurizer pressure

channel would result in opening a PORV. However, the 2/4 closure

logic will re-close the PORV when pressurizer pressure drops below

2200 psia. With the current logic three failed high pressurizer

pressure channels are required for the PORVs to inadvertently open

and remain open. Thus it is concluded that there is an increase in

the probability that the PORVs will inadvertently open and remain

open.

However, multiple channels failing high are required for the

PORVs to inadvertently open and remain open. For failure modes such

as loss of power for the transmitter or a failure of the instrument

tubing, the channel will fail low. Failure modes that can result in

the channel failing high are highly unlikely. Further, the new logic

will require energization in order to open the PORVs, further

minimizing the potential for inadvertent opening. These failures,

which result in the PORVs automatically opening and remaining open,

do not disable the ability of the operators to close the PORVs by

taking their control switch to the close position. Thus, it is

concluded that the increase in risk is negligible. The consequences

of inadvertent opening of both PORVs is bounded by the analysis

provided in Chapter 15.6.1 Inadvertent Opening of Pressurizer Safety

or Relief Valve.

In the event of an inoperable pressurizer pressure channel, the

channel will be placed in the tripped condition. This will change

the opening logic from 2/4 to 1/3 and the subsequent closure logic

from 3/4 to 3/3.

[[Page 19533]]

This means that, when a pressurizer pressure channel is inoperable,

a single failure of a pressurizer pressure channel high will cause

both PORVs to open and remain open. Thus it is concluded that the

Technical Requirements Manual (TRM) change which addresses specific

surveillance controls, also results in an increase in the

probability that the PORVs will inadvertently open and remain open.

However, procedural controls will be implemented and controlled in

the TRM that will require a plant shutdown if the channel is

inoperable for more than thirty days.

The setpoint for the PORV opening logic has been selected to

assure that the PORVs will open prior to the safety valves, taking

into account instrument uncertainties. The setpoint will be

specified and controlled in the Technical Requirements Manual. This

minimizes the potential challenges to the pressurizer safety valves

under steam as well as water solid conditions. The PORV closure

logic will be 3/4 that actuates when pressurizer pressure drops 20

psi below the opening setpoint. Since the stroke time for the PORV

is very short, the closing pressure is adequate to assure that the

valve will cycle as designed.

An EOP [Emergency Operating Procedure] change will direct the

operator to open the PORV block valve if it has been closed due to

excessive seat leakage. The EOP change will not result in the

opening of the PORV block valve when the power has been removed when

required to prevent a small break LOCA [loss-of-coolant accident].

This includes leakage from the PORV such that there is no assurance

that the PORV would re-close as required to control RCS pressure.

Thus, the PORV block valve would be opened only when there is

assurance that the PORV will open and re-close as required. Thus,

the EOP change does not impact the probability of a failed open

PORV.

Credit is now being taken for the PORVs to prevent challenges to

pressurizer safety valves under water relief. If the PORVs were to

fail to control RCS pressure, it is possible for water relief

through the safety valves to occur. This also can result if both of

the PORV block valves cannot be opened. Since the safety valves and

the associated piping are not qualified for water relief, the valves

may be damaged and may not reseat, resulting in an unisolable RCS

leak. However, this would require multiple failures since the PORVs

are redundant. The accident analysis has shown that DNB [departure

from nucleate boiling] is not a concern and thus, there would be no

failed fuel associated with this event. In addition, any RCS leakage

would be inside containment. The analysis provided in FSAR [Final

Safety Analysis Report] Section 15.6.1 for an Inadvertent Opening of

a Pressurizer Safety or Relief Valve bounds the opening of both

PORVs since the capacity of two PORVs is equivalent to one

pressurizer safety valve.

Thus it is concluded that the proposed changes do not involve a

significant increase in the probability or consequence of an

accident previously evaluated.

2. Create the possibility of a new or different kind of accident

from any accident previously evaluated.

The changes provide added assurance that an Inadvertent ECCS

Actuation at Power Operation will be mitigated and meet the

requirement that a moderate frequency event will not lead to a more

serious event without additional failures. The PORVs and associated

piping have been qualified for water relief. In addition the PORVs

are QA [Quality Assurance] equipment and are single failure proof.

The TS changes provide assurance that the PORV automatic function

will be OPERABLE or the plant will be shutdown. By crediting the

PORVs, there is added assurance that the operators will terminate

the event and prevent water relief from the safety valves for which

they are not qualified. Since all criteria are met for this event,

this does not represent the possibility of an accident of a

different type.

Because of the change in the PORV automatic actuation circuitry

and the changes in the channel operability and surveillance

requirements, the change does increase the probability of an

Inadvertent Opening of both PORVs but the consequences are bounded

by the analysis provided in FSAR Section 15.6.1 for Inadvertent

Opening of a Safety or Relief Valve. Thus, this does not represent

an accident of a different type.

Credit is being taken for the operator to open a PORV block

valve if it has been closed due to excessive PORV seat leakage. The

PORV block valve will be opened following a Safety Injection

actuation only after it has been determined that RCS pressure is

above the HPSI [high pressure safety injection] shut off head. This

means that charging is sufficient to maintain RCS pressure well

above the RCS pressure predicted for the limiting LOCA analysis.

Further, the PORV block valve would not be opened when power has

been removed because of the potential for operation of the PORV to

result in a small break LOCA. Further, the potential for opening the

PORV block valve when the PORV is needed for accident mitigation is

already addressed in the TS and is part of the licensing basis.

Thus, this does not create the possibility of an accident of a

different type.

3. Involve a significant reduction in a margin of safety.

With the proposed changes, all criteria for the Inadvertent ECCS

actuation at Power Operation are met. The changes provide added

assurance that a moderate frequency event would not result in a more

serious event without additional failures. The TS changes and EOP

change provide added assurance that the PORVs would be available to

mitigate this event. Opening the block valve when the PORV can be

used to mitigate an accident without the potential for a small break

LOCA is already addressed in the TS and is part of the licensing

basis. Inadvertent Opening of both PORVs is bounded by the Chapter

15 accident analysis. Thus, it is concluded that the changes have no

impact on the margin of safety.

In conclusion, based on the information provided, it is

determined that the proposed revision does not involve an SHC.

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. 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 May 20, 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

[[Page 19534]]

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 Learning Resources Center, Three Rivers Community-Technical

College, 574 New London Turnpike, Norwich, Connecticut, and at the

Waterford Library, ATTN: Vince Juliano, 49 Rope Ferry Road, Waterford,

Connecticut. 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 Lillian M. Cuoco, Esq., Senior

Nuclear Counsel, Northeast Utilities Service Company, P.O. Box 270,

Hartford, Connecticut, 06141-0270, 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 14, 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 Learning Resources Center, Three Rivers

Community-Technical College, 574 New London Turnpike, Norwich,

Connecticut, and at the Waterford Library, ATTN: Vince Juliano, 49 Rope

Ferry Road, Waterford, Connecticut.

Dated at Rockville, Maryland, this 15th day of April 1998.

For the Nuclear Regulatory Commission.

Stephen Dembek,

Project Manager, Special Projects Office--Licensing, Office of Nuclear

Reactor Regulation.

[FR Doc. 98-10332 Filed 4-17-98; 8:45 am]

BILLING CODE 7590-01-P