ML20065E521

Application for Amend to License NPF-58,adding Action Statement to Address Inoperable Containment Airlocks Interlock Mechanism in Tech Spec 3.6.1.3

ML20065E521
Person / Time
Site:	Perry
Issue date:	09/19/1990
From:	Lyster M CENTERIOR ENERGY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20065E523	List: ML20065E547 PY-CEI-NRR-1217, Application for Amend to License NPF-58,adding Action Statement to Address Inoperable Containment Airlocks Interlock Mechanism in Tech Spec 3.6.1.3
References
PY-CEI-NRR-1217, NUDOCS 9010020205
Download: ML20065E521 (6)

Text

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GNR PERRY NUCLEAR POWER PLANT Mad Ac$ess:

c 10 CENTER ROAD P.O. BOX 97 Michael D. Lyster PERRY. OHIO 44081 PERRY. OHIO 44D81 Vece President Woear (216)259 3737 September 19, 1990 PV-CEI/NRR-1217 L U.S. Nuclear Regulatory Commission Document Control Desk Vashington, D. C. 20555 Perry Nuclear Power Plant Docket No. 50-440 Technical Specification Amendment Request - Containment Airlocks Gentlemen Enclosed is a request for amendment to the Perry Nuclear Power Plant, Unit 1 Facility Operating License, NPF-58. In accordance with the requirements of 10CFR50.91(b)(1), a copy of this request for amendment has be u sent to the State of Ohio as indicated below.

This amendment requests revision of Technical Specification 3.6.1.3 Actions.

Currently, the Perry Technical Specificetions do not contain a specific Action to address an inoperable containment airlock interlock mechanism. This change request proposes to add a new Action 50 address this occurrence, and to require appropriate compensatory actions to be taken, which vill permit containment entries to be made after the compensatory measures have been accomplished. Additionally, the Action for one inoperable air lock door currently permits continued but limited access for repair of an inoperable inner airlock door, but does not allov limited access for repair of an outer door, or for other required or necessary containment entries. This change request revises the footnote to provide for these other necessary airlock entries.

If you have any questions, please feel free to call.

Sincer ly 9010020205 900919 _

POR ADOCK 05000440: #[ ., O P PNU:"

Michael D. Lys r .

MDL BSFinjc cci NRR Project Manager Sr. Resident Inspector USNRC Region III State of Ohio

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• Operati ng units-Clevelano Elec' ec illumsnating j [/ /

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Attachment 1  !

PY-CEI/NRR-1217 L r Page 1 of 5 l

Summary The primary containment design at Perry provides two personnel airlocks, each '

consisting of two doors interlocked such that only one door may be opened at a time. The personnel access airlocks are briefly described in the Updated Safety Analysis Report (USAR) Section 3.8.2.1.4. As stated in the Technical l Specification Bases Section 3/4.6.1.3 only one closed door in each airlock is  !

required to maintain the integrity of the containment. This design allows entry and exit during normal operation to perform required surveillances, maintenance, inspections, and to perform routine operational activities such ,

as chemistry sampling, reactor water cleanup system operations, and operator rounds. Vithout the ability to perform these activities the plant vould be required to shutdown. Therefore, access to the primary containment is required for continued safe plant operation. q The first of the prop; . e changes deals with adding an Action Statement for an ,

inoperable airlock into ock mechanism. Since the only purpose of the i interlock is to assure '.nat both airlock doors are not open at the same time, a broken interlock doer not directly affect the safety function of the airlock. This proposed change request is requesting a modification to Technical Specification 3/4.6.1.3. The change proposee an additional ACTION statement to describe actions required when an access airlock mechanical interlock becomes inoperable. Presently, due to the lack of an Action for an inoperable interlock, the plant is conservatively enterir.g Action b.,

declaring the airlock inoperable, and requiring the plant to be shutdown if the interlock cannot be fixed within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. This unnecessarily requires plant shutdown, even though the safety function of the airlock can be ,

adequately maintained. ,

This ci:ange proposes the compensatory measures to be taken if an interlock is -6 inoperable to assure at least one OPERABLE airlock door is maintained shut at all times while the interlock remains inoperable. To maintain a. level of assurance equivalent to the mechanical interlock, the proposed change requires that one operable door remains shut and locked at all times, or that an -

individual is dedicated to assuring that both airlock doors are not opened simultaneously.  ;

The second portion of the proposed change deals with modifying the

• footnote.

As presently written this footnote permits entry through an OPERABLE outer airlock door to repair an inoperable inner airlock door. A time restriction of I hour per year was included in this footnote to limit the total time an airlock could have a door opened while its corresponding door is inoperable. i The proposed change vill maintain the one hour time restriction, but modify the footnote to also perait opening an operable inner door if an outer door is incperable, and also to permit this action for cases other than repair activities. As stated above, periodic, but important entries are required to be made through the containment airlocks. Also, Perry has already experienced two occasions when technicians vere inside the containment and were delayed i exiting due to both personnel airlocks being inoperable. In both cases, the current wording of the footnote prevented the technician frot opening the i inner airlock door for his exit due to the outer docr in the airlock being .

l considered " inoperable." These two occasions are documented in LER 88-032, l

e-.

4 Attachment 1 PY-CEI/NRR-1217 L Page 2 of 5 and LER 90-007. To address situations such as these, the footnote has been .

changed to permit opening of either airlock door when the associated airlock  !

door is inoperable and to identify those types of activities for which the  !

limited access through an airlock with an inoperable airlock door is

• permitted. The one hour per year time limit vill remain.

Finally, the Bases are being revised to discuss use of the airlocks when an airlock door or an interlock mechanism is inoperable. ,

Safety Analysis  ;

There are two personnel airlocks providing access into the primary containment at Perty. Each of the airlocks employs a dual door design, which permits personnel access through the airlock, while always maintaining containment

- integrity by having one of the two doors closed. As stated above, only one of  :

the two doors is required to be closed to maintain containment integrity. t During normal airlock operation a mechanical interlock operates to physically i prevent both doors from being opened at the same time. As long as compensatory actions are taken to assure that both doors are not opened '

simultaneously, the interlock could be inoperable without any decrease in safety. The proposed Action statements provide this assurance. Proposed i Action b.1 assures that at least one OPERABLE airlock door is maintained closed. This gives the operators assurance that the airlock is OPERABLE and i ' least one of the airlock doors is closed.

Actions b.1 and b.2 provide added assurance that at least one OPERABLE door will remain closed by either locking closed one of the OPERABLE airlock doors, or, as provided by the footnote ** by stationing an individual dedicated to  ;

assuring that only one airlock door is open at any time. This option of stationing an individual is necessary to the design of the Perry Nuclear Power Plant. Frequent entries into Primary Containment are necessary during normal t plant operation. As briefly discussed in the summary, there are numerous activities such as surveillances, maintenance, inspections, operator rounds, sampling, and operational system manipulations that are required to be  ;

performed inside the primary containment. Without these activities being ,

performed, the facility would be required to be shutdown, resulting in unnecessary cycling of plant systems. Although personnel access could be performed while maintaining one of the airlock doors locked at all times, the safety of the personnel involved would at times be compromised by the locked doors, such that they may not be able to exit Primary containment during an accident, or other personnel may not be able to enter Primary Containment to aid injured workers, depending on which side of the door the lock vas placed <

on. For this reason the option of stationing a dedicated individual at the airlock to assure that one airlock door is closed at all times (without the need to place a lock on a door at the same time that the individual is stationed) is required. ,

As stated in the Techr.ical Specification Bases Section 3/4.6.1.3 only one door is required to be closed in each airlock to maintain primary containment integrity. The proposed compensatory actions for an inoperable interlock mechanism gives assurance that the containment integrity vill be maintained,

Attachment 1 PY-CEI/NRR-1217 L ,

Page 3 of 5 and thus there is no decrease in safety due to this proposal. By establishing a separate Action for an inoperable interlock mechanism the facility vill no longer be required to declare the entire airlock inoperable due to e ,

inoperable interlock mechanism. Presently, the plant conservatively declares  ;

the airlock inoperable any time an interlock mechanism is inoperable. By the present Action b. a plant shutdown is required if the interlock niechanism cannot be made OPERABLE vithin 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. It is felt that this action is a l detriment to plant safety, since it puts the plant and its systems through a shutdown cycle even though the safety function of the airlock can be ,

adequately assured. The Bases have been revised to add a brief discussion of l the use of the airlock during the period when an interlock mechanism is inoperable.

The second portion of this change involves modification of the current * ,

footnote. The revision to the

• footnote vill increase plant safety. The footnote as written permits entry through an OPERABLE outer airlock door to repair an inoperable inner airlock door. The footnote establishes a cumulative time limit of I hour per year for this condition to exist. As '

written, this footnote is overly restrictive and hampers personnel and plant safety, and also may prevent repairs to an inoperable outer door. 5 First, personnel safety may be hampered by the existing footnote. As discussed in the summary above, twice plant personnel have been inside containment performing required evolutions when the out6r airlock door became inoperable, preventing their exit from containment without violating the Technical Specifications (in both cases the other airlock was also inoperable,  ;

' leaving no exit pathway from the containment due to the vording of the footnote). This delayed the personnel exits, and under emergency situations could result in personnel injury, or delaying emergency response personnel in aiding an injured person inside containment.

Secondly, the footnote as written could also prevent personnel from responding

• to an alarm or-condition inside containment which has the potential to affect plant safety. For example, the control-rod drive scram accumulators are located inside containment and are monitored by a control room annunciator for ,

pressure, and for water leakage on the nitrogen side of the accumulator. If this control room alarm is received an operator is sent into containment to ,

recharge or drain the alarming accumulator as appropriate. Without access to ,

the containment this operation could not be completed and the accumulator in question may degrade to the point where it may have an adverse effect on the control rods scram time. Therefore, entry into containment under this condition is considered the appropriate action.

Third, the outer door may malfunction in such a way that the only way to repair the outer door is to gain accere through the inner door to the inside of the airlock. For instance the outer door linkage may be jammed on the inside such that it vill not open. Repair parsonnel vould then be required to gain access to containment through the other airlock, then gain access to the airlock with the jammed outer door by using the OPERABLE inner door. As currently written, the footnot- vould not permit this operation.

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k Attachment 1 i PY-CEI/NRR-1217 L '

Page 4 of 5 t

The revised footnote vill permit access to and from the containment and to an  ;

inoperable outer airlock door without changing the time restrictions of the present footnote. The present footnote permits use of an VPERABLE door on an '

airlock with the corresponding door inoperable for a cumulative period of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> per year. The proposed footnote maintains this restriction. The only '

change is to permit the OPERABLE door to be either the inner or outer door. '

As noted within the proposed footnote and the Bases, access through an operable airlock door is limited to certain types of activities repair of the i inoperable door; personnel safety and required operational / maintenance /sur-veillance activities necessary to ensure safe plant operations.

Significant Hazards Analysis The standards used to arrive at a determination that a request for amendment requires no significant hazards consideration are included in the Commission's .

Regulations, 10 CFR 50.92, which state that the operation of the facility in I accordance with the proposed amendment would not (1) involve a significant increase in the probability or consequences of an accident previousif evaluated, (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. CEI has reviewed the proposed change with respect to these three factors.

This change doe = act involve a significant increase in the probability or consequences or an accident previously evaluated.

The probability of occurrence of a previously evaluated accident is not increased because the containment airlocks do not affect the initiation of any accident. Therefore this change to add action requirements for an inoperable airlock interlock mechanism and to revise the wording of the footnote addressing use of the operable airlock door can not increase the probability of an accident previously evaluated.  ;

The consequences of an accident remain bounded by conditions which exist prior to this change, s uce operation under the provisions of the proposed changes to the airlock Actions does not produce potential containment leakage paths beyond the currently approved Technical Specifications. For the inoperable airlock interlock mechanism, at least one OPERABLE airlock door vill be maintained closed at all times thus meeting the requirements for the airlock doors. In the case of having one airlock door inoperable, the OPERABLE door on that airlock cannot be used for more than I hour per year which is the same restriction in place under the existing Technical Specification. In approving the current restriction, the NRC previously evaluated the potential for an event  :

requiring primary containment integrity occurring during the limited time when an airlock door is inoperable and its associated operable door is open, and determined that it is suf ficiently remote to justify limited av:ess when required. This change maintains the same cumulative time limit for these entries but revises the restrictions on the circumstances required to exist to allow entry. Therefore, the changes addressing the interlock mechanism and the current footnote cannot increase the consequences of any accident previously evaluated by the NRC.

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i; Attachment 1 PY-CEI/NRR-1217 L l Page 5 of 5  ;

This proposed change does not create the possibility of a new or different  !

kind of accident from any previously evaluated.

Containment airlocks are designed and assumed to be used for entry and ,

exit. Their operation does not interface with the reactor coolant pressure boundary or any other machanical or electrical controls which '

could impact the operations of the reactor or its direct support systems.

Therefore a new or different accident cannot be created. As discussed above the integrity of the containment is maintained as long as at least one OPERABLE airlock door is closed. The proposed change to the airlock '

door interlock mechanism does not change the requirement to have at least one OPERABLE door closed at all times. Instead it assures that this is in fact still occurring by locking one door closed, or by stationing an individual dedicated to assuring that one OPERABLE door is always closed.

As such this proposed change does not create the possibility of a new or  !

different type of accident. Likevise, the proposed change to the

• 1 footnote does not create the possibility of a new or different kind of accident, since the conditions of the containment and its airlock.

remains unchanged and the actual operating mode and procedures for the airlock are unsfiected by these Technical Specification changes.  ;

The proposed change does not involve a significant reduction in the margin of safety.

The applicable margin of safety consists of maintaining the primary containment leak rates within the assumptions of the design' basis accident analysis. Vith regard to the containment airlocks, these leak rates are maintained provided at least one operable airlock door remains closed during the event. The period of time that an airlock could have no operable door closed was previously limited to "a cumulative time not i to exceed I hour per year." This time remains unchanged, therefore the margin of safety is not reduced.

Vith an inoperable interlock, the proposed action vill still maintain at least one operable airlock door closed at all times. Therefore, the assumed margin of safety is not reduced.

Environmental Consideration The Cleveland Electric Illuminating Company has reviewed the proposed Technical Specification change against the criteria of 10 CFR 51.22 for environmental considerations. As shown above, the proposed change does not involve a significant hazards consideration, nor increase the types and amounts of effluents that may be released offsite, nor significantly increase individual or cumulative occupational radiation exposures. Based on the foregoing, CEI concludes that the proposed Technical Specification change meets the criteria given in 10 CFR 51.22(c)(9) for a categorical exclusion l from the requirement for an Environmental Impact Statement.

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