ML20035F888

Regulatory Review of NUMARC Emergency Action Levels

ML20035F888
Person / Time
Site:	Perry
Issue date:	04/20/1993
From:	Boynston S NRC
To:
Shared Package
ML20035F887	List: ML20035F886 ML20035F888
References
TAC-M85476, NUDOCS 9304230016
Download: ML20035F888 (13)

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Enclosure Perry Nuclear Power Plant Regulatory Review of NUMARC Emergency Action Levels TAC No. : M85476 Lead Reviewer: S. Boynton I. BACKGROUNT) 10 CFR 50.47(b)(4) and Appendix E to Part 50 require licensees to maintain a standard emergency classification scheme that is discussed with and agreed upon by State and local authorities and approved by the NRC. In Revision 3 to Regulatory Guide 1.101,

" Emergency Planning and Preparedness for Nuclear Power Reactors", the NRC endorsed NUMARC/NESP-007, " Methodology for Development of Emergency Action Levels" (EALs), as an alternative method for licensees to meet the requirements of 10 CFR 50.47(b)(4) and Appendix E to Part 50. By [[letter::PY-CEI-NRR-1584, Forwards Temporary Change 7 to Rev 10 to Emergency Plan, Table 4-1, EALs to Incoporate NUMARC-based EALs for Comparison Matrix Between NUMARC/NESP-007 & PNPP EALs Also Included|letter dated January 12, 1993]], the Cleveland Electric Illuminating Company forwarded Revision 10 to the Perry Nuclear Power Plant j

(Perry) Emergency Plan, incorporating the NUMARC methodology. Division of Reactor

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Projects forwarded the changes to the Emergency Preparedness Branch for review under TAC Number M85476.

The proposed EALs have been discussed with the State of Ohio and local counties of Lake, Geauga and Ashtabula. A letter of concurrence from each of the government agencies was included with Cleveland Electric's submittal. These agencies have, however, reserved formal approval until NRC review comments are resolved. Consequent to this, and based upon the staff's involvement in the development of NUMARC/NESP-007, the licensee has requested NRC approval of the proposed EAL changes prior to implementation.

II. LICENSEE PRESENTATION On February 5,1993, the staff hosted representatives from Cleveland Electric to present their revised EALs. The presentation described Perry's philosophy on EAL format and clarified site specific EAL thresholds. The licensee also provided justifications for all deviations from the NUMARC methodology. Dialogue with the licensee was extremely beneficial for the staff and our review of the revised EALs. Comments and concerns raised i

during the meeting are included, as applicable, in this review.

i The following is a list of attendees for the Perry /NRC meeting:

B. Farrell Licensing - Cleveland Electric J. Anderson Site EP Coordinator - Cleveland Electric G. Mitchell Emergency Planning - Cleveland Electric J. Hopkins Senior Project Manager - Perry B. Wetzel NRR/ Project Engineer 9304230016 930420 PDR ADOCK 05000440 F

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A. Nelson NUMARC J. Eaton NUMARC M. Kirk NUMARC M. Lyon Illinois Power - Clinton T. Ploski EP Specialist / Region III H. Simons EP Specialist / Region III J. O'Brien EP Specialist /PEPB/NRR A. Mohseni EP Specialist /PEPB/NRR S. Boynton EP Specialist /PEPB/NRR E. Fox Sr. EP Specialist /PEPB/NRR R. Hasselberg Project Manager /PDST/NRR R. Emch Section Chief /PEPB/NRR F. Kantor Section Chief /PEPB/NRR III. PERRY SITE-SPECIFIC EMERGENCY ACTION LEVELS - REVISION 10 A. General Comments The licensee has formatted their EALs into fifteen (15) recognition categories, A through O, as opposed to the four (4) categories described in NUMARC/NESP-007.

This deviation from the NUMARC format provides more consistency with other site procedures and does not, in itself, exclude any of the NUMARC Initiating Conditions (ICs).

Where specific EALs require lists, tables, graphs, etc. to determine whether or not an IC threshold has been met, the licensee has indicated that these will be incorporated into the EAL scheme. The applicable information will be provided on the tab of each recognition category. This will preclude operators from having to reference additional documents and/or procedures.

To improve the human-factors aspect of the EALs, the licensee has indica d that they will conduct verification and validation on the emergency classification procedure.

The procedure will then be revised, as necessary, to incorporate feedback from emergency response organization personnel and operators.

It is noted that many of the Perry EALs mirror those in NUMARC/NESP-007. Only the EALs that deviate from the NUMARC methodology or those with site-specific variations will be discussed further.

B. Recoenition Cateeory A - Fission Product Barrier Deeradation

1. AU2 - Reactor Coolant System Leakare The Perry EAL states:

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i Unidennfed leakage greater than 10 gpm indicated on recorder 1E31-R618, Drywell Floor Drain Sump Fill Rate and Sump Level, on panel 1H13-P642.

NUMARC IC SU5 states:

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Thefollowing conditions exist:

i Unidennfied orpressure boundary leakage greater than 10 gpm.

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a.

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b. Idennped leakage greater than 25 gpm.

j Comment: The licensee has deviated from the NUMARC guidance by excluding identified leakage as an EAL for the initiating condition. The licensee contends

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that identified leakage comes from known, monitored locations such as valve packing and pump seals which do not represent a " leak before break" concern.

i They also state that the NUMARC limit of 25 gpm is equivalent to their technical specification limit for identified leakage and is well within the vessel make-up capacity. Note: Perry's technical specification limit for unidentified l

leakage is 5 gpm.

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Excessive leakage, identified or unidentified, poses a degradation in the level of safety of the plant and warrants the declaration of an Unusual Event.

During the development of NUMARC/NESP-007, the staff agreed with NUMARC's plan to separate non-emergency reportable events from its EAL j

methodology. This included the elimination of technical specification required shutdowns as Unusual Events. The philosophy is that entering a technical specification action statement in and ofitself, does not represent an emergency condition. The threshold for an Unusual Event should, therefore, be set somewhat higher than the technical specification limit.

1 The licensee should revise its proposed EALs to include identified leakage. In light of the above discussion the licensee may propose an EAL for identified leakage that has a higher threshold for declaring an Unusual Event.

2. AA1 - Main Steam Line Break Outside Containment With Isolation Comment: The technical basis for this IC incorrectly states that the initiating condition is only satisfied if the Main Steam Line fails to isolate when called upon to mitigate an accident. This statement should be corrected to indicate isolation has occurred.

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3. Table A Ession Product Barrier Matrix

a. General Comment i

1 The licensee has imposed a condition on the matrix such that it is used "during accident conditions only." This condition injects an unacceptable level of subjectivity into the fission product barrier matrix by requiring the Shift Supervisor to make a determination on whether or not accident conditions exist. Also, a majority of the Unusual Event and Alen ICs do not necessarily indicate that accident conditions exist, i

but in fact, are precursors to accidents. If clarifications are needed, the licensee should consider adding caveats to individual sections of the l

matrix. The broad statement "for use during accident conditions only" is inappropriate and should be deleted.

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b. RPV I.evel - Primary Containment Challence The site-specific EAL states:

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Any of the below limits are i

exceeded for 20 minutes AND 1

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I2 vel CANNOT be restored I

and maintained greater than i

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-30 inches indicated on Fuel i

Zone indicator OR level CANNOT be restored and maintahed greater than the top of active fuel read as wide range recorder

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OR During RPV level instrumentation restoration, reactor water level is unknown for greater than the

' Maximum Core Uncovery Time Limit

• OR Rset6r iset~E..nnk.n.o..w.n.

AND Rhet6FPieb iCANNOT be restored and maintained i

.1 greater than Minimuta "i Ahernate Floodine Presmre Comment: The licensee has defined several thresholds which indicate that Peak Clad Temperature (PCT) may have reached 1500 *F. This is equivalent to the core being uncovered for the Maximum Core i

. _._ _ __.._ _ _ ____ _ _.__.._._._,._ _ _.._.. _. - ~ _,... - -

i Uncovery Time Limit (MCUTL) which is defined as the time required for the PCT to reach 1500 *F. The AND statement at the beginning of the EAL allows operators an additional 20 minutes to recover level before declaring the Gcneral Emergency. The licensee states that using indications of a PCT of 1500 *F, plus a finite time of 20 minutes, is more indicative of the onset of severe core damage.

The conditions that exist in NUMARC's potential loss of containment EAL represent imminent melt sequences which, if not corrected, could lead to vessel failure and increased potential for containment failure.

Severe accident analyses have concluded that function restoration procedures can arrest core degradation in a significant fraction of the core damage sequences, and the likelihood of containment failure is very small in these wents. Given this, NUMARC has applied the MCUTL as a reasmble period to allow the Emergency Operating Procedures (EOPs) to arrest the core melt sequence. If the EOPs have been ineffective in restoring level within the MCUTL, " success" paths have been exhausted. Therefore, postponing declaration of a General Emergency and the issuance of Protective Action Recommendations (PARS) beyond this point would not embrace the anticipatory intent of EAL thresholds and is not in the interest of public health and safety.

The licensee should eliminate the 20 minute requirement or provide a stronger technical justification for its inclusion.

c. Drvwell/ Containment Dressure - Containment Loss The licensee has eliminated the following EAL:

Containment pressure response not consistent with LOCA conditions.

The licensee argues that this EAL is too vague for accurate analysis by the Emergency Coordinator and, therefore, requires a judgement by the Coordinator as to whether or not pressure response is " normal". The licensee contends that this condition is captured under the umbrella of

" Emergency Director Judgement." The staff finds this deviation acceptable.

d. Drywell/ Containment Pressure - Reactor Coolant System Loss The qualifier "with indications of a leak inside Drywell" was added to the Drywell Pressure Isolation Setpoint of 1.68 psig. This precludes Alert declarations for non-emergency events such as loss of Drywell cooling. As this clarifier does not change the underlying intent of the NUMARC EAL, its addition is acceptable.

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e. RCS Leak Rate - Reactor Coolant System Imss i

The NUMARC EAL, " Indication of Main Steamline Break", has been removed from the fission product barrier matrix and developed as a separate EAL under Alert AA1. Escalation to a Site Area Emergency l

when the break is unisolable is provided through EALs under "RCS I.eak Rate" and " Containment Isolation Valves." The underlying intent of the NUMARC EAL has not been changed, therefore, this deviation is acceptable.

f. RCS Leak Rate - Reactor Coolant System Challence j

The licensee has eliminated the NUMARC EAL for potential loss of the RCS:

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RCS leakage GREATER THAN 50 GPM inside the drywell.

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The licensee explains that engineering calculations indicate that the i

containment will isolate due to high drywell pressure for leakage less than 50 gpm. This will isolate the area sump pumpout rate measurement and preclude the operator's ability to evaluate this EAL.

In lieu of the NUMARC required leak rate, Perry proposes to use the containment isolation setpoint of I.68 psig. In accordance with the l

1 licensee's calculations, this is a more conservative EAL. Approval of this deviation will be based on the staff's review of the licensee's engineering calculations. The licensee should provide these to the staff.

C. Eeronnition Categorv B - Loss of Shutdown /Cooldown Functions BS1 - Complete Loss of Functions Needed to Achieve Cold Shutdown i

Comment: The licensee's EAL requires loss of functions needed for cold shutdown while NUMARC's guidance calls for loss of functions needed for hot shutdown. The deviation is based upon differences in mode definitions between PWRs and BWRs. For a BWR, entering Hot Shutdown merely requires the reactor mode switch to be placed in " shutdown". Therefore, to meet the intent of the NUMARC IC, the Perry EAL addresses loss of decay heat removal function and ultimate heat sink. The loss of reactivity control is covered under Recognition Category C, Anticipated Transient Without Scram. The staff considers this to be an acceptable deviation.

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i D. Recoenition Cateeorv C - Anticipated Transient Without Scram l

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1. CU1 - Failure of the Reactor Protection System (RPS) Instrumentation to Initiate or Complete an Automatic Reactor Scram Once an RPS Setooint Has l

Been Exceeded AND Manual Scram Achieved " Shutdown Under All Conditions j

Without Boron."

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I Comment: The licensee has submitted a major deviation to the NUMARC guidance by reducing an ATWS scenario with successful manual scram to the level of Unusual Event. Escalation of the event to an Alert would be via CA1 I

which assens that the manual scram was only successful in reducing power to less than 4%.

t As stated in NUMARC/NESP-007, the failure of the RPS to automatically scram the reactor is more than a potential degradation of a safety system in that a front i

line automatic protection system did not function in response to a plant transient.

Thus plant safety has been compromised and design limits of the fuel may have been exceeded. An Alert is appropriate because conditions exist that lead to a j

potential loss of the fuel clad or RCS. The licensee shi,ld delete this IC to j

conform with the established guidance.

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2. CA1 - Failure of the Reactor Protection System (RPS) Instrumentation to Initiate or Complete an Automatic Reactor Scram Once an RPS Setooint Has Been Exceeded AND Manual Scram was Successful in ONLY Reducine Power Below 4%.

Comment: The licensee has included the condition that the manual scram was successful in ONLY reducing power below 4% whereas the NUMARC guidance

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specifies that the manual scram was successful. The basis in NUMARC /NESP-007 for the Alert classification of this event describes a successful scram as a rapid insertion of control rods which bring the reactor suberitical.

The continued production of power in the core following a limiting transient (ie.

MSIV closure) can lead to exceeding thermal limits of the fuel and j

overpressurization of the RCS. This not only represents the failure of a front i

line automatic protection system and a potentialloss of the fuel clad and RCS, but a major failure of a plant function needed for the protection of the public.

Therefore, if the manual scram is unsuccessful in bringing the reactor suberitical, l

a Site Area Emergency should be declared.

The licensee raised a concern that there may be events where control rods may not indicate full in after the attempted scram, e.g. several rods

• bounce out of the fullin position." In these cases an unwarranted Site Area Emergency would be declared if the licensee's EOP definition of a successful scram was utilized in the EAL. The staff does not believe that a Site Area Emergency is warranted in an event where all rods do not indicate full in as along as the reactor is

i suberitical following the rapid insenion of the control rods. All available indications should be specified in the EAL to ensure the reactor is suberitical, e.g. APRMs downscale, IRMs and SRMs indicating decreasing count rates once fully insened.

Tne licensee should revise this IC to state that the manual scram was successful and add to the EAL the indications that would be used to make that determination.

3. CSI - Failure of the Reactor Protection System (RPS) Instrumentation to Initiate or Complete an Automatic Reactor Scram Once an RPS Setooint Has Been Exceeded AND Manual Scram Was NOT Successful.

Comment: In light of the discussion in CA1 above, the licensee should revise the associated EAL to more accurately reflect the failure of the manual scram.

The staff believes that a Site Area Emergency declaration is appropriate in the event of a failure of both automatic and manual scrams to brine the reactor suberitical. Regardless of whether or not power is reduced below some threshold, if the core remains critical due to insufficient rod insertion there is a potential for high power levels in localized regions of the core (depending upon the resulting rod pattern), and the potential for power surges from cold water injection or reactor pressure changes. This type of event has the potential to degrade core and plant conditions rapidly. Therefore, APRM power level alone will not necessarily provide an accurate measure of the threat to plant safety and level of risk to the public, and does not embrace the anticipatory nature of EALs.

Other indications must also be used to aid in the Shift Supervisor's assessment of the success of the scram. See discussion from CA1 above.

E. Recognition Categorv F - Fire /Exolosion FAI - Fire OR Explosion Affecting the Operability of Plant Safety Systems Recuired to Establish or Maintain Safe Shutdown The site-specific EAL states:

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Confirmed fire OR explosion in a safe shutdown building.

AND Aff6ctedg()Mdowspiiamets(iddist[degn ded performanc*s QR Report by'plintTpeis6hdel"bf Wible'dainsis'id~i^sifs shut'do.wn building or equipment sontainedyithin the ssfe; thatdown buildingj AND Both divisions of safe shutdown equipment were affected by the event.

Comment: The licensee has raised the threshold of this IC above that intended by NUMARC/hT.SP-007. The basis for the NUMARC IC delineates that only one of the redundant trains of safety systems needs to be affected to declare the Alert. The statement made in Perry's EAL that "both divisions of safe shutdown equipment were affected..." implies that the function, not system, must be degraded or lost prior to dcclaration. Thus, the licensee is proposing relief from the NUMARC guidance to preclude the declaration of an Alert when a fire or explosion degrades only one train of safe shutdown equipment. This was discussed during the February 5th meeting.

It is imponant to note that this EAL addresses a fire and not necessarily the degradation in performance of affected systems. System degradation is addressed in the System Malfunction EALs. The reference to damage of systems is used to identify the magnitude of the fire and to help discriminate against minor fires.

The reference to safety systems is included to discriminate against fires in areas where there is a low probability of affecting safe operation of the plant. The significance here is not that a safety system was degraded but the fact that the fire was large enough to cause damage to these systems. Thus, the designation of a single train was intentional and is appropriate.

The licensee should revise this EAL to indicate that only a single train need be affected to declare the Alert.

F. Recognition Category G - Increased Plant Radiation Release GA2 - Release of Radioactive Material or increases in Radiation Levels Within Safe Shutdown Buildings That Impedes Operation of Systems Reauired to Maintain Safe Operations or to Establish or Maintain Cold Shutdown.

The licensee has included in their EAL the following statement:

Access is requiredfor safe plant Operation, but is impeded, due to dose rates.

Comment: The addition of the latter part of this argument into the EAL appears to be redundant. The initiating condition dictates that radiation levels should be high enough as to impede safe operations. The licensee has defined that thre:. hold as 5000 mrem /hr. Once these area rad levels are reached, and access l

to the area is required, the Emergency Director should not be obligated to make a qualified judgement on whether or not access is impeded. It is implicit.

Therefore, the licensee should delete the words "...but is impeded, due to radiation dose rates."

G. Recoenition Catenorv H -Increased Radiation Release to the Environment Comment: The licensee has incorporated the revised guidance in EPA 400,

" Manual of Protective Action Guides and Protective Actions for Nuclear i

Incidents", into their EALs based on offsite doses. The EALs incorporate the concepts of Total Effective Dose Equivalent (TEDE) and Adult Thyroid Committed Dose Equivalent. This is an approved deviation based upon the January 1,1994 implementation of EPA 400 and the revised 10 CFR Part 20.

When dose calculations cannot confir n exposures less than the established I

thresholds, the licensee will use vent monitor readings to trigger the emergency classification. The vent monitor thresholds were not available prior to the licensee's submittal and, therefore, not included in the EALs. These must be provided to the staff prior to approval of the site-specific EALs.

H. Recognition Category I-Control Room Evacuation l

IS1 - Control Room Evacuation Has Been Initiated. but Plant Control CANNOT Be Established.

M Perry EAL states:

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Control room evacuation has been initiated per < ONI-C61 >,

" Evacuation of the Control Room."

AND All required Remote Shutdown Panel Transfer Switches CANNOT be placed in EMERG at either the Division 1 or Division 2 Remote i

Shutdown panels in accordance with instruction <IOI-11 >, " Shutdown from Outside Control Room", within 15 minutes of the SRO in charge of the Control Room physically leaving the Control Room.

Comment: During the February 5th meeting, the licensee argued that transfer of plant control per 101-11, " Shutdown from Outside the Control Room", takes longer than the 15 minute timeframe provided in the NUMARC guidance. As a result, they have attempted to pinpoint a step in the procedure that they can equate with transfer of " plant control" and which can be reached within that 15 minutes. The staff disagrees with this approach in that it is not necessarily indicative of the operators ability to control critical safety functions.

When conditions warrant the evacuation of the Control Room, operators must be able to both monitor the plant transient, and reestablish control of those safety functions required for placing and maintaining the plant in cold shutdown. This IC assumes that monitoring of critical parameters is available and that no coincident events / faults have occurred (ie. LOCA, Loss of Power, etc.). It is designed to capture the specific circumstance where control of the safety functions cannot be reestablished within a reasonably short period of time. The Shift Supervisor / Emergency Director, upon arriving at the Remote Shutdown Panel, should quickly evaluate the viability of the safety functions (ie. ability to cool the core and provide inventory make-up). If this determination cannot be made within a site-specific time, the event should be upgraded to a Site Area Emergency. An EAL with an extension to the 15 minute time limit for making this determination may be appropriate based upon the time required to complete site-specific control transfer procedures. However, any deviation beyond 15 minutes should be accompanied with a technicaljustification and it should be understood that other EALs, such as JSI, " Inability to Monitor a Significant Transient in Progress" and the Fission Product Barrier Matrix, will escalate the event regardless of the time limit imposed in this EAL.

In summary, the licensee should revise the second argument in this EAL to more accurately reflect that plant control is reestablished. In consideration of the above discussion, the licensee may also provide justification for an extension of the 15 minute limit, if warranted.

i I. Recoenition Catecorv L - Natural / Destructive Phenomena LUI, LA1 - Natural and Destructive Phenomena Affecting.

Comment: For the Unusual Event and Alert ICs the licensee has included an EAL based upon low lake level as confirmed by the U.S. Coast Guard.

However, there is no letter of agreement with the Coast Guard to provide this information. Also, due to Perry's underwater intake structure, these levels do not directly correspond to a reduction in the level of plant safety. The licensee i

should delete these EALs based upon the inability to implement them as written.

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SU5 NARY AND CONCLUSION Based upon our review of Perry's emergency action levels against the guidance set forth in NUMARC/NESP-007, we have concluded that the revised EALs meet the intent of the guidance and do not decrease the effectiveness of the emergency plan with the exceptions noted within. The following is a summary of our comments requiring action by the licensee:

A.

AU2 - The licensee should revise this proposed EAL to include identified leakage.

B.

AA1 - The technical basis should be corrected to indicate that main steam line isolation has occurred.

C.

Table A-1

1. The statement "for use during accident conditions only" should be deleted.

2. For challenge to primary containment based upon RPV level, the licensee should delete the 20 minute time requirement or provide a stronger te;hnical justification for its inclusion.

3. For challenge to the RCS based upon RCS leakage, engineering calculations i

supporting the deviation should be provided.

D.

CU1 - This IC should be deleted.

E.

CA1, CSI - The licensee should requalify the success of the manual scram based upon sustained suberiticality to discriminate between the Alert and Site Area Emergency classes.

F.

FAI - The EAL should be revised to indicate that only one train need be affected by the fire.

A G.

GA2 - The words "...but is impeded, due to radiation dose rates" should be deleted.

H.

ISI - The second argument of this EAL should be revised to more accurately reflect when plant control is reestablished.

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LUI, LA1 - These EALs should be deleted based upon the inability to implement them.

Our approval of the revised EAL scheme will be based upon satisfactory resolution of these concerns.

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