Commonwealth Edison Company (Zion Nuclear Power Station, Unit Nos. 1 and 2)

NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-295 and 50-304]

Commonwealth Edison Company (Zion Nuclear Power Station, Unit

Nos. 1 and 2)

Exemption

I

Commonwealth Edison Company (ComEd or the licensee) is the holder

of Facility Operating License Nos. DPR-39 and DPR-48, which authorize

operation of the Zion Nuclear Power Station, Unit Nos. 1 and 2, at a

steady-state reactor power level not in excess of 3250 megawatts

thermal. The facilities are pressurized water reactors located at the

licensee's site in Lake County, Illinois. The licenses provide, among

other things, that the Zion Nuclear Power Station is subject to all

rules, regulations, and Orders of the U.S. Nuclear Regulatory

Commission (the Commission or NRC) now or hereafter in effect.

II

Sections III.C and III.D.3 of 10 CFR part 50, appendix J, require

that Type C local leak rate periodic tests shall be performed during

reactor shutdown for refueling, or other convenient intervals, but in

no case at intervals greater than 2 years. These requirements are

reflected in the Zion Technical Specifications (TS) as requirements to

perform type C containment leak rate testing in accordance with 10 CFR

part 50, appendix J, and approved exemptions.

III

The licensee has determined that certain containment isolation

pathways have not been locally leak rate tested (type C tests) as

required by appendix J to 10 CFR part 50. In a letter dated August 16,

1995, the licensee requested relief from the requirement to perform the

type C containment leak rate tests of certain penetrations and valves

in these pathways in accordance with the requirements of sections III.C

and III.D of 10 CFR part 50, appendix J. On August 16, 1995 the staff

authorized in writing, continued operation of the Zion units in a

notice of enforcement discretion (NOED) until such time as the staff

acted on the exemption requests. In a letter dated November 20, 1995,

the staff granted the schedular exemptions requested in the licensee's

letter of August 16, 1995, and granted schedular exemptions for the

permanent exemption requests to allow time for additional staff review

and until final staff action could be taken. In its letter of November

28, 1995, and supplemented on December 6, 1995, the licensee requested

that certain schedular exemption requests be granted as permanent

exemptions.

The licensee's letter of November 28, 1995, requested permanent

exemptions for components in the following containment penetrations:

Units 1 and 2: P-70, Valve 1(2)SF8767, Refuel Cavity to

Purification Pump; P-99, Valve 1(2)SF8787, Purification Pump to Refuel

Cavity.

The licensee's letter of November 28, 1995, also requested that the

following permanent exemption requests be changed to schedular

exemption requests.

Units 1 and 2: P-77, 1(2)PP0101, 1(2)PP0102, 1(2)PP0103, 1(2)PP0104

(Penetration Pressurization to Containment Valve Stations); P-102,

1(2)AOV-RC8029 (Primary Water to the Pressurizer Relief Tank).

For unit 1, the penetrations would be tested during the refueling

outage in the fall of 1995, and for unit 2, they would be tested during

the next cold shutdown of sufficient duration, and subsequently

thereafter as required. For P-77 and P-102, the staff's letter of

November 20, 1995, granted schedular exemptions until December 31,

1995, at which time final action will be taken. This schedular

exemption still applies for units 1 and 2.

The licensee's letter of November 28, 1995, also requested that for

P-44, the permanent exemption request be changed to a schedular

exemption request. In a letter dated December 6, 1995, the licensee

withdrew the previous requests because it intends to test the

penetration in accordance with the requirements of 10 CFR part 50,

appendix J.

The licensee's request dated November 28, 1995, justified the

proposed permanent exemptions for P-70 and P-99 on the following basis.

For P-70 and P-99, the tests were intended to be performed with air

by installing a hole plug to allow a pressure source hookup while

maintaining an adequate pressure boundary. During a walkdown of the

test boundary, it was identified that the design of the piping for

these penetrations does not allow draining of accumulated water in the

line and, therefore, prevents a proper leak rate test with air per the

requirements of 10 CFR part 50, appendix J. The piping configurations

were not known to the licensee when the exemption request dated August

16, 1995, was submitted. For P-70, in addition to not being able to

completely drain the line, the dose rates for the location where the

hole plug would have to be installed are extremely high, on the order

of 1-2 Rem/hour. For P-99, the piping configuration is such that the

location of the test connection would pose a personnel safety issue

since the connection is located on the side of the refueling cavity

approximately 30 feet above the cavity floor. In its submittal dated

November 28, 1995, the licensee, therefore, requested a permanent

exemption to be allowed to perform the test with water. If the

exemptions were approved, dewatering of the lines would not be

necessary, and the isolation for the test boundaries would be by other

means. The test would be performed by pressurizing the subject valve

with water to approximately 100 psig (greater than Pa, which is 47

psig) and inspecting the valve for leakage. The acceptance criterion

will be the same as the other tests which use water as a test medium,

zero leakage.

The leakage pathways for P-70 and P-99 do not consist of through-

valve

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leakage paths, but rather leakage paths out of containment isolation

valves through valve diaphragms. The potential leakage paths are small

or restrictive and are through cracks or tears in valve diaphragms. The

leakage path for a significant leak to occur requires a sequence of

events for which the probability of occurrence is low. The proposed

test, with water as the test medium and with a zero leakage acceptance

criterion, is conservative enough to provide reasonable assurance of no

significant increase in risk to health and safety of the public when

compared to testing with air. In addition, seismic support of the

systems, missile protection, and, for P-70, the isolation valve seal

water system all provide additional assurance that the risk of a

significant leak is minimal.

To justify granting an exemption to the requirements of 10 CFR Part

50, Appendix J, a licensee must show that the requirements of 10 CFR

50.12(a)(1) are met. The licensee stated that its exemption requests

meet the requirements of 10 CFR 50.12(a)(1), for the following reasons:

Criteria for Granting Exemptions are Met per 10 CFR 50.12(a)(1)

1. The requested exemptions and the activities which would be

allowed thereunder are authorized by law.

If the criteria established in 10 CFR 50.12(a) are satisfied, as

they are in this case, and if no other prohibition of law exists to

preclude the activities which would be authorized by the requested

exemption, and there is no such prohibition, the Commission is

authorized by law to grant this exemption request.

2. The requested exemption will not present undue risk to the

public.

As stated in 10 CFR 50, Appendix J, the purpose of primary

containment leak rate testing is to assure that leakage through

primary containment and systems and components penetrating primary

containment shall not exceed the allowable leakage rate values as

specified by the Technical Specifications or associated bases and to

ensure that the proper maintenance and repairs are made during the

service life of the containment and systems and components

penetrating primary containment. The requested exemption is

consistent with this intent for those penetrations in that alternate

means of ensuring leakage remains acceptably low will be performed

as proposed herein.

3. The requested exemption will not endanger the common defense

and security.

The common defense and security are not in any way compromised

by this exemption request.

In addition, the licensee must show that at least one of the

special circumstances, as defined in 10 CFR 50.12(a)(2) is present. One

of the special circumstances that a licensee may show to exist is that

the application of the regulation in the particular circumstance is not

necessary to achieve the underlying purposes of the rule. The purposes

of the rule, as stated in Section I of 10 CFR 50, Appendix J, are to

ensure that: (1) Leakage through the primary reactor containment and

systems and components penetrating containment shall not exceed

allowable values, and (2) periodic surveillance of reactor containment

penetrations and isolation valves is performed so that proper

maintenance and repairs are made. The staff has reviewed the licensee's

proposal and has concluded that the proposed alternative tests will

confirm the integrity of the subject pathways. Therefore, application

of the regulation in this particular circumstance is not necessary to

achieve the underlying purpose of the rule.

IV

Sections III.C and III.D.3 of 10 CFR Part 50, Appendix J, require

that Type C local leak rate periodic tests shall be performed during

reactor shutdown for refueling, or other convenient intervals, but in

no case at intervals greater than 2 years.

The licensee proposes exemptions to these sections which would

provide relief from the requirement to perform the Type C containment

leak rate tests of certain valves in accordance with the requirements

of Sections III.C and III.D of 10 CFR Part 50, Appendix J.

The Commission has determined that, pursuant to 10 CFR 50.12(a)(1),

this exemption is authorized by law, will not present an undue risk to

the public health and safety, and is consistent with the common defense

and security. The Commission further determined that special

circumstances, as provided in 10 CFR 50.12(a)(2)(ii), are present

justifying the exemption; namely, that the application of the

regulation is not necessary to achieve the underlying purpose of the

rule.

Therefore the Commission hereby grants the following exemption:

The requirement of 10 CFR Part 50, Appendix J, to pressurize the

valves in penetrations P-70 and P-99 with air or nitrogen is not

necessary. Instead, the test pressure medium may be water.

Pursuant to 10 CFR 51.32, the Commission has determined that

granting these exemptions will not have a significant impact on the

human environment (60 FR 63549).

Dated at Rockville, Maryland, this 11th day of December 1995.

For the Nuclear Regulatory Commission.

Jack W. Roe,

Director, Division of Reactor Projects--III/IV, Office of Nuclear

Reactor Regulation.

[FR Doc. 95-31254 Filed 12-22-95; 8:45 am]

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