ML20127B142

Proposed Tech Specs Re Bldg Atmospheric Control Sys

ML20127B142
Person / Time
Site:	Crane
Issue date:	06/18/1985
From:	GENERAL PUBLIC UTILITIES CORP.
To:
Shared Package
ML20127B123	List: ML20127B119 ML20127B132 ML20127B142
References
NUDOCS 8506210366
Download: ML20127B142 (45)

Text

b LIMITING CONIDITIONS FOR OPERATION 3.7.7 CONTROL ROOM EERGENCY AIR CLEANUP SYSTEM -

3.7.7.1 The Control Room Ventilation and Emergency Air Cleanup System shall be OPERABLE with:

a.

Two Control Room supply Fans.

b.

Deleted, c.

Deleted.

d.

Two isolation dampers in the outside air intake duct.

e.

The Control Room air inlet radiation monitor OPERABLE.

APPLICABILITY: RECOVERY MODE ACTION:

a.

With one Control Room Supply Fan inoperable, restore the inoperable fan to OPERABLE status within 7 days.

b.

Deleted.

c.

Deleted.

d.

With one isolation damper in the outside air intake duct inoperable, restore the inoperable damper to OPERABLE status or close the duct within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by use of at least one isolation damper secured in the closed position.

e.

With the Control Room Air Inlet Radiation Monitor inoperable, restore it to OPERABLE status or place the Control Room Emergency Air Cleanup System in the recirculation mode of operation within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

8506210366 950618 PDR ADOCK 05000320 p

PM THREE MILE ISLAND - UNIT 2 3.7-4 TSCR NO. 49

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LIMITING CONDITIONS FOR OPERATION

-b.

With no Fuel Transfer Canal (deep end) water level instruments OPERABLE, terminate all activities involving any Canister containing core material in or over the Fuel Transfer Canal (deep end) and/or all activities involving the plenum assembly and all operations involving changes in the Fuel Transfer Canal-(deep end) water inventory and restore one inoperable instrument to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

FUEL TRANSFER CANAL (DEEP END) WATER LEVEL 3.9.4 The water level in the Fuel Transfer Canal (deep end) shall be maintained at the level specified per NRC approved procedures.

APPLICABILITY: Whenever any Canister containing core material and/or the plenum assembly is in the Fuel Transfer Canal (deep end).

ACTION:

With the Fuel Transfer Canal (deep end) water level not in accordance with approved procedures, terminate all activities involving any Canister containing core material in or over the Fuel Transfer Canal (deep end) and/or all activities involving the plenum assembly and restore the water level to within specification within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

FLEL HANDLING BUILDING / AUXILIARY BUILDING AIR CLEANUP SYSTEMS 3.9.12.1 The Fuel Handling Building Air Cleanup Exhaust System shall be OPERABLE with one of the four system air cleanup exhaust fans OPERABLE.

APPLICABILITY: RECOVERY MODE ACTION:

With the Fuel Handling Building Air Cleanup Exhaust System inoperable, restore the system to OPERABLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or, suspend all operations involving movement of liquid and gaseous radioactive wastes in the Fuel Handling Building (other than sampling evolutions required by the Technical Specifications or RECOVERY OPERATIONS PLAN) until the system is restored to OPERA 8LE status.

THREE MILE ISLAND - UNIT 2 3.9-2 TSCR NO. 49

I LIMITING CONDITIONS FOR OPERATION 3.9.12.2 The Auxiliary Building Air Cleanup Exhaust System shall be OPERABLE with one of the four system air cleanup exhaust fans OPERABLE.

APPLICABILITY: RECOVERY MODE ACTION:

With the Auxiliary Building Air Cleanup Exhaust System inoperable, restore the system to OPERABLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, or suspend all operations involving movement of liquid and gaseous radioactive wastes in the Auxiliary Building (other than sampling evolutions required by the Technical Specifications or RECOVERY OPERATIONS PLAN) until the system is restored to OPERABLE status.

ACCIDENT GENERATED WATER 3.9.13 Discharge of ACCIDENT GENERATED WATER shall be prohibited until approved by the NRC. ACCIDENT GEERATED WATER shall be discharged in accordance with procedures approved pursuant to Specification 6.8.2.

APPLICABILITY: RECOVERY MODE ACTION:

None except as provided in Specification 3.0.3.

REACTOR BUILDING SUMP WATER 3.9.14 Deleted.

THREE MILE ISLAND - UNIT 2 3.9-3 TSCR NO. 49

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SURVEILLANCE REQUIREENTS 4.7.6.1.3 A Special' Report shall be prepared and submitted to the Commission within 10 days if evidence of degradation is noted during an inspection. This report shall describe the extent and nature of the degradation and the plans and schedule for restoring the dike and erosion protection to a status equivalent to the original design provisions.

4.7.7 CONTROL ROOM EERGENCY AIR CLEANlP SYSTEM 4.7.7.1 The Control Room Emergency Air Cleanup System shall be demonstrated OPERABLE:

a.

At least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by verifying that the control room air temperature is less than or equal to 1000F.

b.

At least once per 18 months by verifying that on a control room air inlet radiation test signal or chlorine detection test signal, the system automatically switches into a recirculation mode of operation.

THREE MILE ISLAND - UNIT 2 4.7-4 R0PCR NO. 31

f.

. SURVEILLANCE REQUIREENTS This page intentionally left blank.

THEE MILE ISLAND - UNIT 2 '

4.7-5 ROPCR NO. 31

SURVEILLANCE REQUIREENTS 4.9 LIQUID RADWASTE STORAGE SPENT FUEL STORAGE POOL "A" WATER LEVEL MONITORING 4.9.1 The Spent Fuel Storage Pool "A" water level monitoring instrumentation shall be demonstrated OPERABLE as required by Table 4.3-7.

4.9.2 Verify that surveillance of Spent Fuel Storage Pool "A" water level is being performed in accordance with NRC approved procedures.

FUEL TRANSFER CANAL WATER LEVEL MONITORING 4.9.3 The Fuel Transfer Canal (deep end) water level monitoring instrumentation shall be demonstrated OPERABLE as required by Table 4.3-7.

4.9.4 Verify that surveillance of the Fuel Trcqsfer Canal (deep end) water level is being performed in accordance with NRC approved procedures.

FUEL HANDLING BUILDING /A'JXILIARY BUILDING AIR CLEANUP SYSTEM 4.9.12.1 The Fuel Handling Building Air Cleanup Exhaust System shall be demonstrated OPERABLE:

A.

At least once per 31 days by verifying that the Air Cleanup Exhaust System in the normal operating mode meets the following conditions:

1.

Deleted.

2.

Filter Pressure Drop: The d/p across the combined HEPA filters and charcoal adsorbers shall not exceed 6 inches water gauge.

3.

Fuel Handling Building Pressure: Demonstrate that the system is capable of achieving a negative pressure within the building equal to or greater (more negative) than 1/8 inch water gauge with respect to atmospheric. It may be necessary to close doors and other building openings to achieve the required value.

THREE MILE ISLAM) - UNIT 2 4.9-1 R0PCR NO. 31

.2.

b' SURVEILLANCE REQUIREMENTS B.

At least once per 18 months by verifying that the ventilation system meets the following conditions:

1.

. Visually inspect each filter train and associated components in accordance with Section 5 of ANSI N510-1980, as required by Regulatory Position C.5.a of Regalatory Guide 1.52, Revision 2, March 1978. The inspection should be performed prior to the flow q

and DOP tests of this section.

'l 2.

Flow Test: Exhaust flow rate shall be wthin 18,000 cfm to s

s, 27,000 cfm operating band for each filter train with one filter

')

train and one exhaust fan operating. Testing shall be in accordance with ANSI N510-1980, Section 8.3.1, Paragraphs 3 and 4.

3.

DOP Test: Each filter train shall be tested in accordance with n

Section 10 of ANSI N510-1980, as required by Regulatory Position C.S.c of Regulatory Guide 1.52, Revision 2, March 1978. Flow i

through the filter train being tested shall be as prescribed for the flow test in Section 4.9.12.1.b.2 above.

f NOTE:

Installed system flow instrumentation is adequate for the test described in 4.9.12.1.b.3 above.

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TtflEE MILE ISLAND - UNIT 2 4.9-la Change No. 27

SURVEILLANCE REQUIREENTS

4..

. Fuel Handling Building Pressure: Demonstrate that the system is

capable of ' achieving a negative pressure wthin the building equal to or greater (more negative) than 1/8 inch water gauge with-respect to atmospheric. It may be necessary to close doors and other building openings to achieve the required value. A test instrument, such as.an inclined manometer or equivalent, shall be used in the performance of this test.

c.

After structural maintenance of the EPA filter or charcoal adsorber housings, or following fire or chemical release in.any ventilation zone connunicating with the system by verifying that the ventilation system meets the following conditions:

1.

Flow Test: Reverify exhaust flow rate for the affected filter

-train (s) per Section 4.9.12.1.b.2.

2.-

Filter Pressure Drop: Reverify the' filter pressure drop surveillance prescribed in Section 4.9.12.1.a.2 for the affected filter train (s).

3.

DOP Test: Each affected filter. train shall be' retested in accordance with Section 4.9.12.1.b.3.

d.

After each complete or partial replacement of a EPA filter bank by verifying that the ventilation system meets the following conditions:

.l..

DOP Test: Each affected filter train shall be retested in accordance with Section 4.9.12.1.b.3.-

NOTE:.

Supply fans may be operated as desired except that the number of operating supply fans shall not exceed the number of operating

-exhaust fans.

4.9.12.2 The Auxiliary Building Air Cleanup Exhaust System shall be demonstrated OPERABLE:

a.

At least once per 31 days by verifying that the air cleanup exhaust s

system in the normal operating mode meets the following conditions:

', 1..

Deleted.'

2..

Filter Pressure Drop:- The d/p across the combined EPA filters and-charcoal'adsorbers shall not' exceed 6 inches water gauge.

T N MILE ISLAND -' UNIT 2-4.9-2.

R0PCR NO. 31

SURVEILLANCE REQUIREENTS 3.

Auxiliary Building Pressure: Demonstrate that the system is capable of achieving negative pressure within the building equal to or greater (more negative) than 1/8 inch water gauge with respect to atmospheric. -It may be necessary to close doors and other building openings to achieve the required value.

b.

At least once per 18 months by verifying that the ventilation system meets the following conditions:

1.

Visually inspect each filter train and associated components in accordance with Section 5 of ANSI N510-1980, as required by Regulatory Position C.S.a of Regulatory Guide 1.52, Revision 2, March 1978. The inspection should be performed prior to um flow and DOP tests of this section.

2.

Flow Test: Exhaust flow rate shall be within 27,000 cfm to 40,000 cfm operating band for each filter train with one filter train and one exhaust fan operating. Testing shall be in accordance with ANSI N510-1980, Section 8.3.1, Paragraphs 3 and 4.

3.

DOP Test: Each filter train shall be tested in accordance with Section 10 of ANSI N510-1980, as required by Regulatory Position 1

C.S.c of Regulatory Guide 1.52, Revision 2, March 1978. Flow through the filter train being tested shall be as prescribed for the flow test in Section 4.9.12.2.b.2 above.

NOTE:

Installed system flow instrtnentation is adequate for the test described in 4.9.12.2.b.3 above.

4.

Auxilia / Building Pressure: Demonstrate that the system is capable of achieving a negative pressure within the building equal to or greater (more negative) than 1/8 inch water gauge with respect to atmospheric. It may be necessary to close doors and other building openings to achieve the required value. A test instrument, such as an inclined manometer or equivalent, shall be

!~

used in the performance of this test.

c.

After structural maintenance of the EPA filter or charcoal adsorber housing, or following fire or chemical release in any ventilation zone communicating with the system by verifying that the ventilation system l

meets the following conditions:

1

1..

Flow Test: Reverify exhaust flow rate for the affected filter l

train (s) per Section 4.9.12.2.b.2.

l 2.

Filter Pressure Drop: Reverify the filter pressure drop l

surveillance prescribed in Section 4.9.12.2.a.2 for the affected l

filter train (s).

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f TmEE MILE ISLAND - UNIT 2 4.9-3 Change No. 15 l

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f SAFETY EVALUATION REPORT FOR SIMPLIFICATION OF TECHNICAL SPECIFICATIONS FOR BUILDING ATMOSPHERIC CONTROL SYSTEMS l

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l Three Mile Island Unit 2 Revision 0 June 1985 l

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TABLE OF CONTENTS 1.0 PURPOSE, SCOPE AND ORGANIZATION 1.1 Purpose 1.2 ' Scope 1.3 Organization 2.0 PROPOSED TECHNICAL SPECIFICATION REVISIONS 2.1 Present Technical Specification Systems Considered 2.2 Proposed Technical Specification Revisions 3.0 REASONS FOR PROPOSED TECHNICAL SPECIFICATION REVISIONS 3.1 Plant Resource Allocation 3.2 Radiological Considerations 4.0 SAFETY EVALUATIONS 4.1 Technical Approach and Criteria 4.2 Affected Plant Systems and Equipment 4.3 Control Room Habitability 4.4 Off-Site Doses Due to Fuel Handling Building Activities 4.5 Off-Site Doses Due to Auxiliary Building Activities 5.0 EVALUATION OF OTHER FUNCTIONS OF AFFECTED SYSTEMS AND COMPONENTS 5.1 Control Room Ventilation and Emergency Air Cleanup System 5.2 Fuel Handling Building Air Cleanup Exhaust System 5.3 Auxiliary Building Air Cleanup Exhaust System 6.0 RADIOLOGICAL CONSIDERATIONS 7.0 10 CFR 50.92 EVALUATION

8.0 CONCLUSION

S

9.0 REFERENCES

hs

'e 1.0 PURPOSE, SCOPE AND ORGANIZATION 1.1 Purpose The purpose of this Safety Evaluation Report (SER) is to provide technical justification for simplification of cer-tain portions of the Three Mile Island Unit Two (TMI-2)

Technical Specifications to reflect the current status of the plant.

The Technical Specification requirements pro-posed for simplification in this SER relate to plant systems and components associated with the air cleanup systems for the control room, fuel handling building, and auxiliary building.

This SER demonstrates that various specified deletions and simplifications of these requirements can be accomplished without adversely affecting the present safe condition of the plant or causing undue risk to the health and safety of the public.

The basic justification for these proposed Technical Spec-ification changes is the recognition that the fundamental condition of the plant has changed since it was first licensed.

The plant is no longer capable of producing the l

potential mass and energy releases discussed in Chapter 15 of the TMI-2 FSAR and, consequently, is no longer in need of parts of the large atmospheric control systems mentioned in Chapter 9 of the TMI-2 FSAR on a continuing basis.

Specifically, due to the stable shutdown condition of the nuclear fuel, the minimal core decay heat generation rate and low core temperature under present loss-to-ambient cooling conditions, the ambient pressure condition of the reactor coolant system with the reactor vessel head removed, i

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w and the improved building radiological conditions, the requirements for building air cleanup systems can be safely reduced.

The purpose of this SER is to evaluate the present plant conditions and show that the TMI-2 Technical Specifications can be simplified in these areas without causing undue risk to the health and safety of the public.

1.2 Scope The scope of this SER includes evaluations of the Technical Specification requirements that cover the following systems:

Containment purge system Control room ventilation and emergency air cleanup system Fuel handling building air cleanup exhaust system Auxiliary building air cleanup exhaust system.

These evaluations are based on the present and anticipated future plant conditions.

Specifically these conditions are:

The plant is in a cold shutdown condition at ambient pressure with the vessel head removed.

The plant is undergoing recovery operations which will include the defueling of the reactor vessel.

1-2

f 1.3, organization Section 2.0 describes the specific functional areas where

' simplifications of Technical Specification requirements are justified, based on the results of the SER.

This section also lists the resulting changes to Technical Specification requirements that are proposed to implement these simpli-fications.

Section 3.0 summarizes the beneficial effects that these Technical Specification changes would have on the allocation of plant resources and the exposure of plant personnel to radiation areas.

Section 4.0 presents the necessary evaluations to show that current plant safety functions and requirements can be satisfied af ter the proposed Technical Specification changes are made.

Section 5.0 evaluates other safety functions of the plant systems and components affected by the proposed Technical Specification changes.

This evaluation shows that reducing or eliminating requirements for these systems and components does not compromise any other current plant essential func-tion.

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Section 6.0 discusses the effect of these proposed Technical l

Specification changes on plant radiological considerations.

l Section 7.0 provides a 10 CFR 50.92 evaluation of these l

Technical Specification changes.

Section 8.0 gives the con-clusions of this SER and Section 9.0 lists references, and l

Attachment l'contains revised Technical Specification pages.

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pr 2.0 PROPOSED TECHNICAL SPECIFICATION REVISIONS 2.1 Present Technical Specification Systems Considered It is the"~ intent of this SER to show the changes which can be made in the TMI-2 ' Technical Specification requirements for the building atmospheric control systems.

2.1.1 Containment Purge System The evaluations of off-site radiation exposures indicate that the purge system Techrcical Specification requirements could be significantly simp.'.ified, since the system is not needed to meet current dose 1imits for normal operations and accident conditions.

However, it is planned to retain the existing Technical Specification requirements in order to minimize potential off-site exposures during defueling operations.

An analysis of reactor building temperature conditions in Reference 9.1 shows that the heating function of the system could be shut down for at least 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> during the coldest winter conditions without any unacceptable consequences.

Accordingly, there is no adverse affect on the continued safe condition of the plant if the purge system is out of service for at least 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> at any time.

2.1.2 Control Room Ventilation and Emergency Air Cleanup System This section summarizes the safety evaluation of this system in this SER.

This evaluation compares effects inside the control room during accident conditions under two modes of 2-1

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~

operation:

(1) system operation as designed with all equip-ment available, and (2) control room isolated without use of bypass fans, or HEPA or charcoal filters.

The results show that the effects are acceptable for both modes, but control room isolation is preferable.

Accordingly, simplifying changes to Technical Specification requirements are proposed to implement this control room isolation mode.

It is also shown that a loss of AC power to this system for at least 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> is acceptable under any foreseeable building conditions.

2.1.2.1 Limiting Radiation Hazard The limiting radiological accident, a TMI-1 loss-of-coolant accident, was evaluated assuming the standard TMI-2 practice of respirator use during radiological accidents.

An iodine protection factor of 50 was assumed for the purposes of this SER.

A justification for this protection factor is included in Section 4.3.1 of this SER.

The evaluations covered two separate operating modes, i.e., (1) system operation as designed with charcoal and HEPA filters in place, and (2) control room isolation with the system not running.

These evaluations, discussed in Section 4.0 of this SER, show that during the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of an accident, lower dose rates to control room personnel occur with the system isolated.

The thyroid dose is limiting for this operating mode but is less than 20 rem compared to the 30 rem guideline contained in Reference 9.2.

On the other hand, if the system is-running with filters in place, the thyroid doses are small but skin beta doses are

high, i.e.,

about 83 rem.

This exceeds the guideline of

' Reference 9.2, i.e., 30 rem for skin beta dose or 75 rem if 2-2

F protective clothing is worn.

Accordingly, it is concluded it would be preferable to shut down and isolate the outside air supply system for at least the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in the event high radiation is detected.

Once the 51rst 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the accident have passed, dose rates are small regardless of the system operating mode.

In the subsequent 30 days, skin beta dose is limiting if the system is operating, and is about 8 rems if the filters remain in place.

With the system isolated, skin beta dose is limiting and corresponds to 3.3 rem.

These results show it would be slightly more desirable to keep the system isolated after the first day, but that the supply fans could be run, if needed, to supply outside air to maintain control room cooling after that time.

The evaluations indicate that the control room isolation mode is preferable and that the only Technical Specification requirements necessary to implement this response are existing operability checks of the air inlet radiation monitor, the air intake isolation dampers, and the supply 1

fans.

The evaluations also indicate that loss of off-site power for greater than 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> is acceptable because control room i

isolation is achieved without AC power and cooling is not l

l needed for greater than 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />.

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2.1.2.2 Limiting External Hazardous Atmospheric Release l

Event For the limiting chlorine gas release accident, the system response anticipated by current Technical Specification l

requirements is to isolate the control room from the normal l

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air intake path and to run both tha cmargancy cir clocnup system, including bypass f ans, HEPA filters and charcoal filter, and the ventilation system in a recirculation mode.

Because the cleanup system filter train cannot remove chemical species of this type, this operating mode relies on isolation.of the control room to provide protection of workers.

The only anticipated use of the recirculation flow is for removal of the room heat load in the long-term.

Since total control room isolation is achieved without AC power, it is acceptable for the systems to be shut down for greater than 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> during this worst case condition.

Accordingly, the only Technical Specification requirements necessary to respond to this event are existing operability checks of the chlorine detector and the air intake isolation dampers.

2.1.3 Fuel Handling Suilding Air Cleanup Exhaust System The principal basis for the existing Technical Specification requirements for this system is the need to control off-site radiological doses due to building activities.

The present requirements anticipate that two of the four exhaust fans and both trains of HEPA filters must be operable to achieve this control.

Evaluations presented in Section 4.0 of the SER show that established off-site dose limits are met for all applicable postulated accidents and measured normal releases without the system in full operation.

Specifically, the off-site dose limits are met if the system operates without HEPA filters or if the system is totally shut down and ground level releases occur.

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In addition, there are other present system functions that have some safety considerations, as discussed in Section 5.0 of this SER.

These include monitoring of airborne radioac-tivity releases, building heating and cooling, and building internal contamination control.

However,.all of these functions 'can be met with the entire system out of service for at least the 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> identified in this SER as a conservative limit for reactor building temperature control, and with reduced Technical Specification operability requirements.

The revised Technical Specifications would (WG) require maintenance of a one-eighth inch water gage building negative pressure without specified flow limits and would require one exhaust fan to be operable.

(Plant experience has shown that one fan is sufficient to maintain this building vacuum).

Operability of HEPA filters would continue to be required although they are not necessary to meet the objectives of any present system safety functions.

2.1.4 Auxiliary Building Air Cleanup Exhaust System The design and safety functions of this system are very similar to the fuel handling building air cleanup exhaust The principal basis for the existing Technical system.

Specification requirements for this system is the need to control off-site radiological doses due to building activi-ties.

The present requirements anticipate that two of the four exhaust fans and both trains of HEPA filters must be operable to achieve this control.

Evaluations presented in Section 4.0 of this SER show that established off-site dose limits are met for all applicable postulated accidents and measured normal releases without the system in full operation.

Specifically, the off-site 2-5

dose limits are met if the system operates without HEPA filters or if the system is totally shut down and ground level releases occur.

In addition, there are other present system functions that have some safety considerations, as discussed in Section 5.0 of this SER.

These include monitoring of airborne radioac-tivity releases, building heating and cooling, and building internal contamination control.

However, all of these func-tions can be met with the entire system out of service for at least the 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> identified in this SER for reactor building temperature control, and with reduced Technical Specification operability requirements.

The revised Technical Specifications would require maintenance of a one-eighth inch WG building negative pressure without specified flow limits and would require one exhaust fan to be operable.

(Plant experience has shown that one fan is sufficient to maintain this building vacuum).

Operability of HEPA filters would continue to be required although they are not necessary to meet the objectives of any present system safety functions.

2.2 Proposed Technical Specification Revisions The following changes are proposed for the TMI-2 Technical Specifications.

\\

l 2.2.1 Containment Purge System No changes proposed.

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2.2.2 Control Room Emergency Air Cleanup System Sections 3.7.7 and 4.7.7 Delete all requirements for operability of the HEPA filters, charcoal filters, cooling coils, and bypass fans.

2.2.3 Fuel Handling Building Air Cleanup System Sections 3.9.12.1 and 4.9.12.1 Delete quantitative flow rate requirements that are based on two of the four exhaust fans operating continuously.

Add a requirement for operability of a single exhaust fan (without quantitative flow limits).

Retain the requirement for main-tenance of a minimum one-eighth inch WG building negative pressure.

2.2.4 Auxiliary Building Air Cleanup System Sections 3.9.12.2 and 4.9.12.2 Same as changes to Technical Specification Sections 3.9.12.1 and 4.9.12.1 described above.

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c, 3.0 REASONS FOR PROPOSED TECHNICAL SPECIFICATION REVISIONS 3.1 Plant Resource Allocation This SER shows that because of the present condition of the plant, some of the present Technical Specification atmos-pheric control systems and components are no longer needed to assure that the plant remains in a safe and stable condi-tion, and to assure that all off-site radiological condi-i tions do not exceed established limits.

The effort required to maintain these systems and components to Technical Specification standards is significant.

If the proposed Technical Specification changes are enacted, these resources can be more effectively redirected to recovery programs and other activities which enhance the overall safe condition of the plant.

3.2 Radiological Considerations Some of the systems and components whose Technical Specifi-cation requirements are proposed for deletion or simplifi-cation in this SER are located in radioactive areas of the i

plant.

If the proposed Technical Specification changes are approved, a savings in radiation exposure due to deletion of equipment surveillance requirements can be achieved.

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O 4.0 SAFETY EVALUATION This section describes the technical approach and general evaluation criteria used in reassessing the need for certain Technical Specification requirements related to TMI-2 build-ing atmospheric control.

Also included are detailed evalua-tions of the effectiveness of the building atmospheric control systems in controlling radioactivity releases and providing control room habitability after the proposed Technical Specification changes are made.

4.1 Technical Approach and Criteria The TMI-2 Final Safety Analysis Report (FSAR) describes the original design basis of the building atmospheric control systems.

These systems were designed for control of the off-site (and in the case of the control room, on-site) atmos-pheric radiological effects from all plant design basis events.

However, the plant is no longer capable of producing the potential mass or energy releases discussed in Chapter 15 of the TMI-2 FSAR; consequently, these origina'l design bases are no longer applicable.

The condition of the plant has changed significantly since the present Technical Specification requirements were established and many requirements can be simplified or deleted.

The technical approach used in demonstrating that such changes are feasible for the building atmospheric control systems is to (1) identify the present condition of the buildings from a radiological standpoint, including the 4-1

status of all significant plant equipment and the potential for future off-normal conditions; (2) review the TMI-2 design basis events and determine the current applicability of these events, and (3) perform evaluations to assess which simpli-fled system responses could meet the established regulatory requirements for radioactivity releases.

As part of the evaluation of the need for present Technical Specification systems, conservative assumptions are made regarding the possible loss of off-site and on-site AC electrical power, the possible occurrence of various design basis events, and current methods of applying regulatory criteria.

Descrip-tions of the evaluation criteria are presented in the following paragraphs.

4.1.1 Design Basis Events (DBEs)

The following Design Basis Events (DBEs) are considered applicable to the current TMI-2 configuration and were con-sidered in the evaluation of this SER. Most DBEs are taken from the TMI-2 FSAR except for the TMI-l LOCA event presented in the TMI-l FSAR.

TMI-2 Loss of reactor coolant system integrity (LOCA)

{

TMI-2 radiological events TMI-l worst case radiological release - LOCA i

Wind and tornados Flood i

Aircraft and tornado missiles i

External hazardous atmospheres Fire 4-2 L

A seismic event is not considered here; it has been con-sidered in a separate SER.

Reference 9.3 recently evaluated the ability of present plant systems to. mitigate the consequences of the bounding loss of RCS integrity at TMI-2.

Since it was shown that all con-sequences of such an occurrence could be successfully con-trolled without contribution from building atmospheric control systems (i.e., the evaluation assumed that the containment purge exhaust system was inoperable), this DBE need not be considered further.

Wind, tornado, flood, and missile events had no impact on these evaluations since all building atmospheric control systems are located in buildings designed to protect against these phenomena.

External hazardous atmosphere and the TMI-l LOCA were considered in the evaluation of the control room ventilation and emergency air cleanup system.

Appropriate TMI-2 radiological events were identified and considered in the evaluations of all the building atmospheric control systems.

Existing fire protection is retained for all systems considered.

4.1.2 Loss of AC Power A complete loss of off-site and on-site AC power is assumed to occur coincident with or after any of the events evaluated.

For the purposes of this SER, it has been shown that a power loss of up to 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> duration is acceptable for the limit-ing case.

An off-site power reliability study (Refer-ence 9.4) shows that a power loss longer than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is very unlikely. Thi's study demonstrates that (1) there are multiple sources of off-site power available to the TMI site and (2) 4-3

p.

in the event powar in 1 cot, it ccn ba rootored within 8 houro with a very high probability.

This reliability analysis considered historical reliability data for those systems that

. feed THI-2.(note power has never been lost to the site) and the reliability of the current grid including redundancy of the variou,s transmission paths from the site switchyard to vital TMI-2 buses.

4.1.3 Regulatory Criteria for Radiological Release Limits All current regulatory criteria for radiological release limits were considered in these evaluations.

These criteria are discussed in detail in the sections that follow.

4.2 Affected Plant Systems and Equipment The following building atmospheric control systems are evalu-ated in Sections 4.3 through 4.5, below.

Control room ventilation and emergency air cleanup system Fuel handling building air cleanup exhaust system Auxiliary building air cleanup exhaust system The evaluations generally considered the performance of these systems under the following simplified conditions of equip-ment operability.

Current active air flow paths with full filtration Current active air flow paths without operable I

j filters l

Complete shutdown of system with total isolation of building or passive air leakage paths only.

i i

4-4

Appropriate conclusions were drawn about the acceptability of proposed system simplifications based on the resulting radio-logical releases (off-site or, in the case of the control room, into the building).

4.3 Control Room Habitability The following evaluations were performed to determine the consequences of simplified Technical Specification require-ments for operability of the control room ventilation and emergency air cleanup system.

A detailed report of this work is given in Reference 9.5.

4.3.1 Radiation Hazards Evaluation Several postulated accidents were considered in this evalua-tion including a TMI-1 waste gas decay tank failure, a TMI-1 fuel handling accident, a TMI-1 main steam line break, and a loss-of-coolant-accident at TMI-1.

It was concluded that the most significant radiological event that could release a plume of radionuclides which could be drawn into the TMI-2 air intake tunnel is the TMI-l LOCA.

The TMI-l LOCA is characterized using information from the TMI-l FSAR, including reactor parameters and the containment leak rate.

The distance from the TMI-1 release point to the TMI-2 air intake tunnel entrance was used to compute the cloud concentrations, and meteorological factors are consis-tent with the appropriate regulatory requirements.

Two conditions of the control room ventilation system are considered in the evaluation.

The first condition assumes 4-5

that the ventilation system operates in the filtered recir-

~

culation mode with 1500 cfm minimum continuous air intake.

This is the mode of operation anticipated by the present Technical specification requirements.

The second condition assumes that the ventilation system is shut down with the control room isolated.

For the second condition, an infil-tration model is developed from the conservative recom-mandations of the USNRC Regulatory Guide 1.78, Reference 9.6, and results in a control room infiltration rate of about 1350 cfa.

For each condition, it is assumed that control room personnel are wearing respirators in accordance with standard TMI-2 practice in the event of a radiological accident.

Full-face respirators with iodine canisters currently have no assigned protection factor against gases and vapors; however, during the THI-2 incident, a protection factor of 50 was granted against radioiodines.

Recent studies at Los Alamos (Reference 9.7) have demonstrated that Triethylene Diamine impregnated charcoal canisters can effectively attenuate radioiodines in the form of elemental iodine, methyl iodide, and hypoiodous acid.

The effectiveness of activated charcoal in adsorbing lodines is also examined in Reference 9.8.

Currently, emergency kits containing two hundred-twenty (220) of this type canisters are stored on-site.

Fifty of these canisters are maintained in the control room.

An additional 1000 spare canisters are maintained in stores.

All are within the current shelf-life and are factory-sealed.

GPU Nuclear currently requires quantitative fit tests with an acceptance criteria of a protection factor greater than 100.

6 4-6

Current industry reports, coupled with on-site experience, available whole-body counters, the TMI standard practice of air sampling, TMI required fit tests for respirator usage, proper storage of canisters, and the availability of adequate respirator supplies, give confidence that a protection factor of 50 against iodine'for canister-equipped respirators is a realistic assumption for use in this safety Evaluation Report.

delf-contained breathing apparatus (SCBA) is also available for control room personnel.

Although not required, this apparatus would also limit personnel radiation exposure.

The allowable doses to control room personnel are 5 rem for whole body gamma, 30 ren for skin beta dose (or 75 rem if protective clothing is worn), and 30 rem for thyroid in accordance with the guidelines of USNRC Standard Review Plan Section 6.4, Reference 9.2.

The results of the evaluations indicate that during the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of an accident the lowest exposures to control room personnel result when the control room is isolated.

The thyroid dose is limiting for this operating condition, but is less than 20 rem compared to the 30 rem allowable dose.

The skin beta dose is about 15 rem for this condition.

If, on the other hand, the system is running with filters in place, the thyroid dose is small but the skin beta dose is limiting, i.e., about 83 rem total integrated dose during the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

There are two basic reasons why running the control room ventilation system increases the skin beta dose; this dose is 4-7

r due primarily to the noble gas xenon and krypton isotopes.

First, the concentration of the noble gases is not affected by the system filters.

Running the system instead of leaving the control room isolated results in a greater flow rate of outside air and noble gas into the control room.

Secondly, meteorological factors are more unfavorable with the system running, so the concentration of the noble gas in the incoming air is increased.

The reason for this is that, with the system running, it is necessary to assume that the intake tunnel is located at the point of highest concentration downwind of TMI-1.

With the system isolated, however, inleakage is spread over the control building and downwind concentrations may be averaged.

Once the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the accident have passed, dose rates are small regardless of the system operating mode.

In the time period from one to 30 days, skin beta dose is limiting if the system is operating and the total dose is about 8 rem.

With the system isolated, skin beta dose is limiting and corresponds to a total dose of 3.3 rem between one and 30 days after the accident.

The results of the above evaluations indicate that the following system operating mode will minimize exposures to control room personnel:

Isolate the system for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following an acciden.

Continue to operate with the system isolated, if possible.

However, the system could be run without a significant dose increase.

4-8

4.3.2 Hazardous Chemical Release Evaluation For the limiting chlorine gas release accident, the system response anticipated by current Technical Specification requirements is to isolate the control room from the normal air intake path and to run both the emergency air cleanup system, including bypass fans, HEPA filters and charcoal filter, and the ventilation system in a recirculation mode.

Because the cleanup system filter train cannot remove chemical species of this type, this operating mode relies on isolation of the control room to provide protection to con-trol room personnel.

Since total control room isolation is achieved without AC power, it is acceptable for the system to be shut down for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or longer during this worst case condition.

4.4 off-Site Doses Due to Fuel Handling Building Activities The following evaluations are performed to determine the radiological consequences of simplified Technical Specifica-tion requirements for operability of the fuel handling build-ing air cleanup exhaust system.

A detailed report of this work is given in Reference 9.9.

4.4.1 Off-Site Doses Due to Normal Activities The evaluation of off-site doses during normal activities is performed in accordance with USNRC Regulatory Guide 1.109, Reference 9.10.

The doses are determined for several path-ways, i.e.

(1) dose due to external radiation from activity deposited on the ground, (2) dose due to inhalation of air which contains activity, and (3) dose due to activity 4-9

n ingested by eating food which contains activity.

The doses avaluated for four different age groups, i.e.,

infant, r

child, teenager, and adult.

For each pathway and age group, the maximum dose received by any organ is determined, i.e.,

bone, liver, total body, thyroid, kidney, lung or gastro-intestinal tract.

Meteorological conditions during normal activities are taken from Reference 9.11.

For the cases where the cleanup system is operating, these conditions are based on elevated release from the plant vent stack.

For cases where the cleanup system is shut down, these conditions are based on ground 1evel release.

The acceptance criterion for off-site dose due to particulate releases during normal activities is 15 mrem in accordance with 10 CFR 50, Appendix I.

Off-site doses due to normal activities are based on past measurements of curie loadirgs on the filters.

In addition, measurements of activity in the SDS off-gas effluents are also used.

The doses are evaluated for three possible configurations of the cleanup nystems (1) total shutdown of the system with ground release, (2) operation of the exhaust fans without HEPA filters, and (3) full operation of the cleanup system with HEPA filters.

I i

The results of the evaluation show that releases for all three system configurations are acceptable.

The limiting releases occur with the system shut down and are 0.059 mrem

{

per year to the infant's liver via the goat milk pathway.

On I

this basis, the cleanup system is not needed to control off-I site releases during normal operation.

4-10 i

i

4.4.2 Off-Site Doses Due To Postulated Accidents A large number of postulated accidents applicable to current and future TMI-2 plant conditions were analyzed in Refer-ence 9.12.

This analysis assumed that all releases were unfiltered and thus Reference 9.12 can be considered bounding for the purpose of this evaluation.

The resulting off-site doses from the accidents analyzed in Reference 9.12 are well within the guidelines of 10 CFR Part 100.

On this basis, the cleanup system is not needed to control off-site releases during potential accidents.

4.5 Off-Site Doses Due to Auxiliary Building Activities The following evaluations are performed to determine the radiological consequences of simplified Technical Specifica-tion requirements for operability of the Auxiliary Building Air Cleanup Exhaust System.

A detailed report of t?is work is given in Reference 9.9.

These evaluations use methods identical to those discussed in section 4.4 of this SER for the fuel handling building air cleanup exhaust system.

Allowable off-site dose limits are also the same.

4.5.1 off-Site Doses Due to Normal Activities The evaluations of off-site doses during normal activities are performed in the same manner as the evaluations of Sec-tion 4.4.1 of this SER.

Assessment of source terms is derived from plant measurements of the curie loadings on the AB air cleanup exhaust system HEPA filters.

The allowable off-site dose due to particulate releases during normal activities is 15 mrem as discussed in Section 4.4.1 of this SER.

4-11

The results of tho cycluationo indicato that off-cita releases are acceptable for all three cases of system oper-ability (1) system shut down, (2) fan flow without HEPA filters, and (3) fan flow with HEPA filters.

The limiting release occurs with.the system shut down'and is.018 mrem to the inf ant's liver via the goat milk pathway.

On this basis, the cleanup system is not needed to control off-site releases during normal activities.

4.5.2 off-Site Doses Due to Postulated Accidents A large number of postulated accidents applicable to current and future TMI-2 plant conditions were analyzed in Refer-ence 9.12.

This analysis assumed that all releases were unfiltered and thus Reference 9.12 can be considered bounding for the purpose of this evaluation.

The resulting off-site doses from the accidents analyzed in Reference 9.12 are well within the guidelines of 10 CFR Part 100.

On this basis, the cleanup system is not needed to control off-site releases during potential accidents.

l 4-12

s 1,.

t 5.0 EVALUATION OF OTHER FUNCTIONS OF AFFECTED SYSTEMS AND COMPONENTS 5.1 Control Room Ventilation and Emergency Air Cleanup System This system has the additional safety requirement of main-taining the control room temperature below the 104*F design limit established for some electrical equipment.

An evalu-ation was performed, as reported in Reference 9.5, of the effect of a loss of AC power on the control room tempera-ture.

This evaluation indicates that, if the control room is initially at its normal temperature of 75'F, the room temperature would increase to about 104*F within 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br />, and to about 110*F within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Typically, temperaturer well in excess of 130*F would be required to produce any adverse temperature effects due to short term exposure.

7 i

Accordingly, it is concluded that keeping the system iso-lated for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> without cooling is acceptable.

5.2 Fuel Handling Building Air Cleanup Exhaust System Additional functions of the FHB air cleanup exhaust system are listed in the TMI-2 FSAR.

Each of these functions is evaluated below.

It is shown here that all safety consider-ations can be met with the entire system out of service for at least as long as the 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> identified in this SER as a conservative limit for reactor building temperature control, and with reduced Technical Specification operability re-quirements.

Simplified Technical Specification requirements for the cleanup system that meet the conclusions of the evaluations o'f this section and Section 4.0 are presented in Section 2.0 of this SER.

l 5-1 r

l l

l l

o 5.2.1 Building Cooling As indicated in Reference 9.9, fuel handling building tem-perature could reach a maximum of 109'F if no cooling were provided in the hottest summer period.

This temperature j

would not, produce any adverse temperature effects due to short-term exposure.

Typically, a temperature in excess of 130'F would be required.

In the long-term, a temperature of 104*F or less is desir-able to minimize aging of the equipment.

Accordingly, it is desirable to provide cooling.

However, this is not consid-ered a safety function.

Reference 9.9 also indicates that a single fan is sufficient to maintain required cooling.

In particular, building temperature can be maintained within 3*F of ambient by oper-ating a single fan.

Accordingly, the current Technical Specification requirements for operating twc fans of one train are not necessary for the cooling function.

5.2.2 Building Heating i

Heating is required in winter to ensure that any tanks or other components containing liquid do not freeze, as well as for personnel comfort.

Clearly, a long period of time would be available to restore heating if it were lost, before freezing temperatures were reached.

Accordingly, this is not considered to be a safety issue.

5.2.3 control of Contamination Within the Building i

This is a useful function which minimizes the spread of con-tamination within the building and minimizes worker expo-sures.

It will continue to be performed by maintaining one operable exhaust fan, and will not jeopardize the health and safety of the public.

Accordingly, it is not a basis for any Technical Specification requirement.

5-2

~

5.2.4 Fire Detection Some fire detectors are located in exhaust system ducting, and operate by sensing smoke in the exhaust air flow.

The

' purpose of these detectors is to shut off the fans and iso-late the building ventilation system if a fire is detected inside the building.

Since the ventilation system dampers automatically isolate' the building upon loss of AC power, this fire protection function of the system is maintained under loss-of-power conditions.

5.2.5 Monitoring Release of Airborne Activity The monitoring function must be performed to satisfy the requirements of 10CFR50, Appendix I.

It requires that the building vacuum be maintained at one-eighth inch W.G.

to ensure that there is no path for continuous out-leakage except via exhaust system ducting.

Plant data indicate that, with both fans of one AB or FHB exhaust train operating, the building vacuum is typically in excess of 0.8 inch W.G.; with only one fan running, the building vacuum would be greater than 0.2 inch W.G.

Accord-ingly, the monitoring function can be satisfied with a single fan running.

5.3 Auxiliary Building Air Cleanup Exhaust System Additional functions of the AB air cleanup exhaust system are described in the TMI-2 FSAR.

Each of these functions is evaluated below.

It is shown here that all safety consider-l ations can be met with the entire system out of service for at least as long as the 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> identified in this SER as a conservative limit for reactor building temperature control.

Simplified Technical Specification requirements for the 5-3 l

l

O I

f cleanup system that meet the conclusions of the evaluations l

of this section and Section 4.0 are presented in Section 2.0 of this SER.

l I

5.3.1 Building Cooling Plant equipment power is supplied from the switchgear and motor controllers located within the Auxiliary Building.

As

]

indicated in Reference 9.9, the Auxiliary Building tempera-l ture could reach a maximum of 126*F if no cooling were pro-i vided in the hottest summer period.

This temperature would not produce any adverse temperature effects due to short-l term exposure.

Typically, a temperature in excess of 130*F would be required.

In the long-term, a temperature of 104*F or less is desir-able to minimize aging of the equipment.

Accordingly, it is desirable to provide cooling.

However, this is not consid-ered a safety issue.

Reference 9.9 also indicates that a single fan is sufficient to maintain required cooling.

In particular, building temperature can be maintained within 3*F of ambient by oper-ating a single fan.

Accordingly, the current Technical l

Specification requirements for operating two fans of one train are not necessary for the cooling function.

5.3.2 Building Heating Heating is required in winter to ensure that any tanks or other components containing liquid do not freeze, as well as for personnel comfort.

Clearly, a long period of time would be available to restore heating if it were lost, before j

freezing temperatures were reached.

Accordingly, this is not considered to be a safety issue.

5-4 l

l

i 5.3.3 control of Contamination within the Building This is a useful function which minimizes the spread of_ con-tamination within the building and minimizes worker expo-sures.

It will continue to be performed by maintaining one operable exhaust fan, and will not jeopardize the health and safety of the public.

Accordingly, it is not a basis for any Technical Specification requirement.

5.3.4 Fire Detection Some fire detectors are located in exhaust system ducting, and operate by sensing smoke in the exhaust air flow.

The purpose of these detectors is to shut off the fans and isolate the building ventilation system if a fire is detected inside the building.

Since the ventilation system dampers automatically isolate the building upon loss of AC power, this fire protection function of the system is maintained under loss-of-power conditions.

5.3.5 Monitoring Release of Airborne Activity The monitoring function must be performed to satisfy the requirements of 10CFR50, Appendix I.

It requires that the building vacuum be maintained at one-eighth inch W.G.

to ensure that there is no path for continuous out-leakage except via exhaust system ducting.

Plant data indicate that with both fans of one AB or FHB exhaust train operating, the building vacuum is typically in excess of 0.8 inch W.G.; with only one fan running, the building vacuum would be greater than 0.2 inch W.G.

Accord-ingly, the monitoring function can be satisfied with a single fan running.

5-5 2

6

6.0 RADIOLOGICAL CONSIDERATIONS

' Some of the systems and components whose Technical Specifica-tion requirements are proposed for deletion or simplification in this SER are located in radioactive areas of the plant.

If the proposed Technical Specification changes are approved, a savings in radiation exposure due to reductions in equip-ment surveillance activities can be achieved.

In addition, the results of this SER show that it is possible to maintain off-site and on-site radiological conditions well within established limits if the proposed changes to the Technical Specification requirements for the building atmospheric l

control systems are enacted.

I 6-1

(...

d 7.0 10 CFR 50.92 EVALUATION Section 50.91 of 10 CFR 50, entitled " Notice for Public Comment; State Consultation", requires the licensee to sub-mit an analysis concerning the issue of "no significant hazards consideration" applying the standards in Section 4

f 50.92 of 10 CFR 50.

10 CFR 50.92 states than an issue involves "no significant hazard consideration" if it would not:

a)

Involve a significant increase in the probability or consequences of an accident previously evaluated.

j l

b)

Create the possibility of a new or different kind of accident from any accident previously evaluated, or c)

Involve a significant reduction in a margin of safety.

1 The conclusions of this Safety Evaluation Report (SER) sup-port selected changes to the TMI-2 Technical Specifications; in addition, this Section demonstrates the proposed Tech-nical Specification changes involve "no significant hazard consideration".

The changes proposed by this SER do not increase the prob-ability or the consequences of an accident previously eval-uated in the safety analysis report.

Under present plant conditions, the requirements for containment, cleanup, and controlled exhaust of building atmospheres are much less than those. required for the conditions evaluated in the Final Safety Analysis Report (FSAR).

7-1

The possibility of a new or different type of accident is not created by the proposed Technical Specification changes.

This conclusion is based on having demonstrated that the envelope of essential plant atmospheric control systems and components is n,ow smaller and simpler than f

considered in the FSAR.

In addition, the margin of safety would not be reduced by the proposed Technical Specification changes.

It has been shown in this SER that the performance of building atmospheric control systems under. the proposed simplified Technical Specification requirements would meet the various licensing-basis safety design criteria such as control of radioactive effluents and loss-of-power requirements.

Therefore, it is concluded that the Technical Specification changes proposed in this SER involve "no significant hazards consideration" as defined in 10 CFR 50.92.

l 7-2 l

8.0 CONCLUSION

S 1

It has been shown in this SER that the TMI-2 Technical Spe-cification revisions listed in Section 2.0 of this SER can be accomplished without causing undue risk to the health and safety of the public.

Furthermore, the proposed revisions would reduce radiological exposures to plant personnel, would continue to assure acceptable off-site and on-site radiological conditions, and would permit more concentrated use of plant resources on recovery program activities.

8-1

s.

9.0 REFERENCES

" 9.1 GPU Nuclear Memorandum DEOE-0679 Attachment 2, Jus-tification for Technical Specification Limit for RCS q

Temperature, January 8, 1985.

9.2 USNRC NUREG-0800 Standard Review Plan Section 6.4, Control Room Habitability System, Revision 2, 1981.

9.3 GPU Nuclear Report, Safety Evaluation Report for Sim-plification of Technical Specifications for Water r

Injection, Core Cooling and Reactor Pressure Control Systems, Three Mile Island Unit 2, Revision 0.

9.4 GPU Nuclear Report, Probability of Loss of Offsite Power at TMI-2, Risk Assessment Section, Licensing and Nuclear Safety Department, Revision 1.

9.5 Burns & Roe Report, Study for Evaluation of the Control Room Ventilation and Cleanup System for the Technical Specification Reduction Program (Task BI-04), Revi-sion 2, December 1984.

9.6 USNRC Regulatory Guide 1.78, Assumptions for Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated Hazardous Chemical Release, June

)

1974.

9.7 USNRC NUREG/CR 3403, Criteria and Test Methods for Certifying Air-Purifying Respirator Cartridges and Canisters Against Radioiodine, August 1983.

9.8 R.R. Bellamy, Elemental Iodine and Methyl Iodine i

Adsorption on Activated Charcoal at Low Concentrations, Nuclear Safety, November-December 1974.

9.9 MPR Report, TMI-2 Technical Specification Reduction Program Task BI-03, Auxiliary Building and Fuel Handling Building Air Cleanup Systems, Revision 1, December 1984.

9.10 USNRC Regulatory Guide 1.109, Calculation of Annual Dose to Man From Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR Part 50, Appendix I, Revision 1, October 1977.

9-1 i-

e..,.

4 9.11 GPU Nuclear Memorandum DEOE-0639 Attachment 2, Task BI-01 Reactor Building Boundary, and Attachment 3, Task BI-02 Need for Containment Purge, November 30, 1984.

'9 12' GPU Nuclear Letter 4410-85-L-0077, GPU Nuclear

. Corporation Seismic Design Criteria, April 16. 1985.

s 9-2

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