ML20199F336

Safety Evaluation Supporting 951227 Request for NRC Approval of Proposed EALs to McGuire Nuclear Station,Units 1 & 2

ML20199F336
Person / Time
Site:	Mcguire, McGuire
Issue date:	01/28/1998
From:	NRC (Affiliation Not Assigned)
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ML20199F326	List: ML20199F322 ML20199F336
References
NUDOCS 9802030139
Download: ML20199F336 (8)

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s* NUCLEAR REGULATORY COMMISSION '

WAsNINGTON, D.C. SMAHo01

\, . . . .. [O 1 SAFETY EVALUATION BY THE OFFICE OF NUCI FAR REACTOR REGULAT!ON REVISED EMERGENCY ACTION LEVEL,$

DUKE ENERGY CORPORATION i

i MCGulRE NUCI FAR STATION. UNITS 1 AND 2

, DOCKET NOS. 50-369 AND 50-370 '

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1.0 INTRODUCTION

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By letter dated December 27,1995, as supplemented by letters dated April 1 and October 23, 1997, Duke Energy Corporation (the licensee) proposed changes to the emergency action levels (EALs) for the McGuire Nuclear Station, Units 1 and 2, in order to implement the i NUMARC/NESP-007 EAL methodology. The licansee provided the following documents in the 3

. original December 27,1995, submittal: a revision to McGuire procedure RP/0/A/5700/00, "Cisssification of Emergency,"which listed the EALs and included guidelines for using the o

EALs to declare an emergency condition; a revision to Section D of the McGuire Emergency Plan, " Emergency Classification System," which provided a basis for each of the EALs and described how the proposed EALs incorporated the guidance in NUMARC/NESP-007, i

" Methodology for Development of Emergency Action Levels," Revision 2, dated January 1992; and a disposition of NUMARC/NESP-007, Revision 2, initiating conditions and EALs in the -

McGuire EAL submittal, which provided a cross-reference between the NUMARC Eats and

! their equivelents under the McGuire EAL numbering scheme. The NRC han endorsed i

NUMARC/NESP-007 as an acceptable method by which licensees may develop site-specific emergency classification schemes.

l The licensee also provided letters from the State and local govemmental authorities in the i

McGuire emergency planning zone (EPZ), indicating that those authorities had reviewed and i agreed with the EALs contained in the licensee's December 27,1995, letter to the NRC.

In response to the NRC's January 15,1997, request for additional information (RAl), the licensee supplemented the original submittal with .vtitional information by letter dated April 1, 1997. The response did not contain agreements b : the State and local govemmental authorities to the changes. However, in its letter u ? Aber 23,1997, the licensee committed I

to ensure that the EALs, as approved by the NRC, would be discussed and agreed upon with the offsite govemmental authorities in the McGuire EPZ before implementation. The i

October 23,1997, letter from the licensee contained additional information requested by the NRC after its review of the licensee's response dated April 1,1997. Further, the request for this additional information was discussed with the licensee in a June 23,1997, teleconference.

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2.0 BACKGROUND

The staff reviewed the revision to the McGuire Units 1 and 2 EALs against the requirements of

- '10 CFR 50,47(b)(4) and Appendix E to 10 CFR Part 50. - Section 50.47(b)(4) specifies that onsite emergency plans must meet the following standard

"A standard classification and action -

level scheme, the bases of which include facility system and effluent parameters, is in use by l the nuclear facility licensee...." Appendix E (IV)(C) specifies that, " emergency action levels

,. _(based not only on onsite ar.d offsite radiation monitoring information, but also on readings from -

a number of sensors that indicate a potential emergency, such as pressure in containment and i response of the emergency core cooling system) for notification of offeite agencies shall be

described....The emergency classes defined shall include (1) notification of unusual events, (2)  ;

l alert, (3) site area emergency, and (4) general emergency." l l In Revision 3 to Regulatory Guide 1.101, " Emergency Planning and Preparedness for Nuclear

! Power Reactors," NRC endorsed NUMARC/NESP-007, Revision 2, " as an acceptable method

! - for licensees to meet the requirements of 10 CFR 50.47(b)(4) and Appendix E to 10 CFR

' Part 50. The staff relied upon the guidance in NUMARC/NESP-007 as the basis for its review of the changes to McGuire's EAL, h

f 3.0 : EVALUATION i The licensee documented the emergency classification system in Section D of the McGuire i

Emergency Plan and in Enclosures 4.1 through 4.7 of McGuire Procedure RP/0/A/5700/0,

" Classification of EmerDency.".

- The classification system closely follows the NUMARC guidance. The EALs are divided into i -seven categories as listed below.

4.1 Fission Product Barrier Matrix 4.2 System Malfunction 4.3 Abnormal Red Levels / Radiological Effluent 4.4 - Loss of Shutdown Function 4.5 Loss of Power 4.6 - Fire / Explosion and Security Events 3

4.7 Natural Disasters, Hazards and Other Conditions Affecting Plant Safety 4

Each category lists the four classes of emergency: notification of an unusual event (UE) , alert, site area emergency (SAE), and general emergency (GE). Under each class of emergency are

. initiating conditions (ICs) that satisfy that class. These ICs are identical to the NUMARC guidance in nearly all cases. Deviations are discussed later in this safety evaluation.

Additionally, procedure RP/0/A/5700/0 lists the operating mode (s) or plant condition for which p

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i each IC is applicable. Procedure RP/C/A/5700/0 also lists EALs under each IC for use by the l_ classifying official, in order to rtompare the EAL to the plant parameters observed, for esse of

[ cleasification.

, Techbg bases for each of tne EALs are contained in Section D of the McGuire Emergency l Plan. ,r,ese bases are separated by category. Eachfige of the technical basis document l contains an IC, its applicable operating mode (s), the EALs that satisfy the IC, the bases for =

ecch EAL under the perticular IC, and a NUMARC reference IC from which the McGuire IC is -

! ' derived, i-

' ;The licensee reviewed the revised EALs with the offsite authorities in the McGuire plume .

exposura pathway EPZ nd provided concurrence letters from these agencies, which indicated  !

' the initial _ offsite agencies approval of the proposed EALs. However, the staff requires that the

[ licensee receive an approval from the offsite govemmental authorities before their implementation of the revised EALs.

l Most of the proposed EALs conform closely to the NUMARC guidance; however, several of the licensee's proposed EALs and ICs depart from the list in NUMARC/NESP-007. Review of the licensee's justification for these variations, as discussed below, found the variations to be

- acceptable.

)- o -. NUMARC ICs AU1 and AA1 contain EALs that require the performance of offsite i assessments of releases of radioactive materials. The licensee did not include provision j for performing these assessments in its original submittal, because the licensee did not

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have an on shift dose assessment capability at the time of the original submittal.-- In its t

. response to the RAl, the licensee stated that it had committed to implement an on-shift dose assessment capability no later than August 1,1997. _The licensee further stated that it did not intend to implement the submitted EAL methodology until that capability l had been restored. On August 4,1997, the licensee submitted Revision 97-3 to the

McGuire Nuclear Site Emergency Plan,' effective August 1,1997, which augmented the -

l capability for on-shift dose assessment. Since the licensee now has on-shift dose L

, assessment capability for the accurate determination of the declaration thresholds for McGuire EALs 4.3.U.1-1,4.3.U.1-2,4.3.U.1-3,4.3.A.1-1, and 4.3.A.1-2, these EALs are

, acceptable, i e NUMARC ICs AU1 and AA1, and their associated EALs, describe emergency conditions arising from uncontrolled releases of radioactive material. The thresholds listed in these EALs are referenced to multiples of release rate limits in the plant's Radiological Technical Specifications. McGuire ICs 4.3.U.1 and 4.3.A.1, and their associated EALs, -

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reference release rate thremholds as multiples of selected licensee commitments L (SLCs). The use of these SLCs is an acceptable attemative to the Radiological 4- Technical Specifications as pomtitted in NRC Generic Letter No. 89-0*, and McGuire -

l License Amendment Nos.11g (Unit 1) and 101. (Unit 2), dated May 22,1991.

e NUMARC EAL AU1.3, AA1.3, AS1.2, and AG1.2 provide for declaration of emergency j conditions based on telemetered site perimeter radiation monitors. The W3uire EAL scheme does not include these EALs since the site does not have this uM af monitor. ~

Since the NUMARC guidance does not require these EALs for plants tha't do not have.

telemetered site perimeter monitors, this omission is acceptable.

e NUMARC EALs AU1.4 and AA1.4 provide for UE and alert declarations, respectively, j

based on uncontrolled releases of gaseous or liquid effbent that exceed threshold

values as read on the automatic real-time dose assessment capability. The McGuire i EAL scheme does not contain equivalent EALs to these NUMARC examples, because i McGuire does not contain any such automatic real-time dose assessment capability.

Since the NUMARC guidance does not require these EALs for sites not having such capability, this deviation is acceptable.

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• NUMARC EAL AU2.3 provides for the declaration of a UE for an unexpected increase in ra, ..on levels surrounding irradiated spent fuel in dry storage. Since the McGuire

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station has no dry fuel storage facilities, it does not in::lude this EAL in its scheme. This is an acceptable deviation from the NUMARC guidance.

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e NUMARC EAL AU2.4 provides for a TIE declaration for valid direct area radiation

! readings in the plant that reflect an increase (by a factor of 1000) over normal levels.

McGuire EAL 4.3 U.2-3 modified the NUMARC guidance by requiring the increase in l radiation levels to be " unplanned" for the EAL to be met. This deviation is acceptable L since the NUMARC guidance, in its basis for this EAL, addresses the fact that these

[ r>6 Mon level increases are assumed to be unplanned in nature.

1 e- NUrk AC EAL AA2.2 recognizes alert conditions for instances in which irradiated fuel is observed to be uncovered. McGuire EAL 4.3.A.2-2 is listed as equivalent to NUMARC EAL AA2.2, but McGuire EAL 4.3.A.2-2 deviates from ths NUMARC example by recognizing conditions that will result in imminant fuel uncov6 ring rather than the actual uncovering of irradiated fuel. The basis for the McGuire EAL states that personnel j

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i observing such conditions should not remain until the fuel is actually uncovered.

' Although the wording of the McGuire EAL increases the subjectivity of this declaration, since it is not tied to an easily observable condition, it ensures a more conservative approach to the declaration of this EAL and greater personnel safety, Therefore, this deviation is acceptable.

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• NUMARC ICs AS1 and AG1 and their associated EALs describe emergency conditions for release of radioactive material that yields site boundary doses tnat approach or exceed Environmental Protection Agency (EPA) protective action guides.- The L NUMARC doses are based on doses to the whole body of child thyroid and expressed in units of milliroentgen. The McGuire EALs equivalent to these NUMARC examples have revised these doses to incorporate the dose equivalents that are listed in the revised EPA and 10 CFR Part 20 methodologies for dose calculations. - These new

- metho6logies consider both the extemal and intomal contributions to radiological dose.

The McGuire EALs list total effective dose equivalent (TEDE) for the whole body and

, committed dose equivalent for the add thyroid. The dose units referenced in the i

McGuire EALs are in mrom TEDE. Because the new EPA methodology is based on protective action guides for the general population, the McGuire EAL use of adult thyroid i i

is acceptable. - Because the revised methodology recognizing effective dose equivalents  !

I is considered an improvement over previous methodologies, the McGuire EAL use of l TEDE is also acceptable.- '

r e - The McGuire EAL submittal has a fission product barrier matrinhat closely follows the NUMARC example. One dev!ation noted is the use of a point system for equating the ,

i status of the barriers with an emergency classification level. The McGuire ma*rix l assigns various point values to EALs that describe conditions challenging the three  ;

i fission product barriers (fuel cladding, reactor coolant system, and primary containment). The point values very according to the specific barrier affected and whether the condition constitutes a loss or potentialloss of that bamer, The points corresponding to the most serious challenge to each barrier are added together and the i point total determines the classification level.- The point total methodology yields results

, consistent with the NUMARC guidance. Its use is acceptable.

-* The NUMARC fission product barrier matrix recognizes several conditions that  ;

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constitute a loss of the fuel cladding barrier. One of these is based on core exit thermocouple readings and another is based on status of the core cooling critical safety i

function status tree (CSFST), which in tum is based on, among other parameters, core i exit thermocouple readings. The inclusion of both of these EALs is redundant in plants using CSFSTs in their emergency operating procedures. McGuire is one such plant.

Consequently, it has eliminated the EAL dealing with core exit thermocouple readings alone. This deviation is acceptable. l l

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. e The NUMARC fission product barrier matrix also has multiple EALs that address a 0

- potentialloss of the fuel cladding barrier. One such EAL is based solely on reactor

vessel water level, and another EAL is based on the core cooling CSFST, which is, in ,

i- tum, based on reactor vessel water level. These EALs are redundant wr McGuire, which uses CSFSTs in its emergency operating procedures. Because of this redundancy, McGuire has eliminated the EAL based solely on reactor vessel water

. level. This deletion is acceptable, a

i o - NUMARC EAL PC6, which recognizes a potential loss of the primary containment barrier, is expressed in terms of core exit thermocouple readings and reactor vessel

level. These indications are those that satisfy the ' red path" condition for the core

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cooling CSFST. The McGuire fission product barrier matrix recognizes a red path j condition in core cooling as satisfying this EAL. Since the recognition of a red path condition is more easily recognized than the conditions listed in the NUMARC guidance, this deviation is acceptable.

t e NUMARC EAL RC3, in the fission product barrier matrix, recognizes a potential loss of l the reactor coolant system (RCS) barrier for primary to secondary leakage that exceeds the capacity _ of one charging pump in the normal charging mode. McGuire EAL 4.1.N.3, which corresponds to this NUMARC example, includes the additional requirement that letdown is isolated for the EAL to be met. This is an acceptable deviation to the -

L NUMARC guidance, since it is normal procedure for operators to isolate the letdown i flow from the RCS as part of diagnosis or response to any RCS leak. The McGuire l' basis provides for considering the EAL satisfied if letdown cannot be isolated, but all other conditions are met. This deviation is acceptable, o NUMARC EAL RC4, in the fission product barrier matrix, recognizes a loss of the RCS _-

j barrier in cases in which the containment radiation monitor channels exceed a site-

specific threshold. The McGuire fission product barrier matrix cioes not contain a

corresponding EAL, because the McGuire containment monitors that would be available L to detect this condition are designed so that they would be insensitive to a loss of the RCS barrier with normal RCS activity. The NUMARC guidance for this particular EAL recognizes this possible condition and recommends omitting this EAL from the site-specific matrix in these cases. This deviation is acceptable, e NUMARC EAL HU1.3 recognizes control room personnel assessment of a natural or destructive event affecting the protected area of the plant as an unusual event (UE).

The McGuire EAL scheme recognizes this NUMARC EAL as redundant to NUMARC EAL HUS.1, which allows declaration of a UE based on the emergency director's judgment. Since tha amergency director would be aware of control room assessments of such events, these two EALs are redundant, and the deletion of EAL HU1.3 from the

McGuire submittalis acceptable, i

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i: . e- NUMARC EAL HU4.2 allows for security events, not already covered by the NUMARC guidance, to be included in site-specific EAL submittals for declaration of a UE. The p . McGuire submittal includes two additional EALs,4.6.U.2 2, which recognize a hostage -

or extortion situation, and 4.6.U.2-3, which recognizes a violent civil disturbance within the owner-controlled area, as additional site-specific examples of security events that .

warrant a UE declaration. These events are consistent with the NUMARC guidance for

! - UE declaration, and their inclusion into the McGuire EAL scheme is acceptable, e- NUMARC IC HA2 specifies the declaration of an alert condition for a fire or explosion ,

affecting the operability of plant safety systems required to establish or maintain safe l shutdown for all operating modes (including the defueled condition). McGuire has divided this IC into two separate ICs 4.6.A.1, applicable in modes 1-6, and 4.6.A.2,  ;

applicable in the defueled condition. This deviation is acceptable because the F ' equipment needed to maintain a safe-shutdown condition while defueled is much less than the needed to maintain a safe-shutdown condition in the other modes.

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• NUMARC EALs SU1,1, SA1.1, SAS.1, SSI.1, and SG1.1 recognize various levels of ,

degraded electrical power supply to essential buses. These EALs list loss of power to l

- certain site-specific transformers as one condition leading to declaration of the l emergency conditions associated with them. The corresponding McGuire EALs do not i list any site-specific transformers, but rather list the essential buses that are affected.  !

Since listing the specific buses is a more direct method of determining the status of i electrical power to them, this deviation is acceptable. '

l l e _ NUMARC IC SU1, which is listed as applicable in all operating modes, recognizes a UE j i

condition for a loss of all offsite power to the essential buses. The single EAL for this IC requires both the loss of the offsite power supplies and the startup and loading of the

[ diesel generators to supply those buses. The McGuire submittal divides this NUMARC

! example IC into two EALs with different applicable modes of operation for each: 4.5.U.1- -

j 1 for operating modes 1-4 and 4.5.U.1-2 for modes 5,6, and the defueled condition.

l EAL 4.5.U.1-1 requires both diesel generators to start and supply the essential buses, EAL 4.5.U.1-2 only requires one diesel generator to supply its respective emergency bus.- This deviation is acceptable since the operability of only one essential bus is l consistent with the Technical Specifications requirements for the operating modes for l which EAL 4.5.U.1-2 is ap#icable. +

e NUMARC EAL SU4.1_ recognizes site-specific radiation monitor readings as indicators of

fuel cladding degradation greater than technical specification limits. There is no i

comparable EAL in the McGuire submittal, since the plant has no such failed fuel monitor. This deletion from the McGuire EAL submittal is acceptable.

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8-e NUMARC EAL SU4.2 rrejnizes site-specrfic levels of reactor coolant activity as measured by sample as inc8icators of fuel cladding degradation greater than technical specification limits. McGuire EAL 4.2.U.3-1 is listed as equivalent to this NUMARC EAL.

Although the NUMARC EAL 10 3U4 is listed as applicable in operating modes, McGuire

~ IC 4.2.U.3 is only listed as applicable in Modes 1-5. The refueling condition (Mode 6) and the defueled condition are not included in the McGuire IC. This is because there is no technical specification limit for coolant activity in either of these cor :litions. Because it would be impossible to natisfy the IC in these conditions, and because the McGuire scheme contains ICs and EALs for all credible events in these operating conditions, which, in turn, would trigger either equivalent or higher classifications than would NUMARC IC SU4 (e.g., damage to irradiated fuel, loss of reactor vessel, spent fuel pit, or reactor cavity level), the deletion of refueling and defueled conditions from the equivalent McGuire IC is an acmptable deviation from the NUMARC guidance.

'e NUMARC IC SS4 recognizes an SAE condition for the complete loss of any function required for achieving or maintaining a hot shutdown condition, The NUMARC guidance allows for site-specific identification of these necessary functions, although the NUMARC basis lists such functions as reactivity control and the ultimate heat sink as those that sites should consider. McGuire IC 4.4.S.2, identified as equivalent to NUMARC lC SS4, lists the CSFSTs of subcriticality and heat sink as the functions whose loss satisfies the IC. The use of these CSFSTs, although not as explicit as the examples stated in the NUMARC basis, represents conditions that meet the intent of the NUMARC guidelines and is easily recognized by control room operators and managers.

The use of these CSFSTs for this IC is acceptable, e NUMARC EAL SG1.1 recognizes conditions resulting from a loss of all power as warranting a GE declaration. McGuire EAL 4.5.G.1-1 has modifieKi this EAL by adding an additional requirement that the standby shutdown facility cannot supply reactor ._

coolant pump seal injection or maintain control air to steam generator relief valves. The successful performance of these functions would preclude the degradation of the critical safety functions associated with fission product barrier integrity. Therefore, this addition

' to the EAL is an acceptable deviation from the NUMARC guidance.

4.0 CONCLUSION

The proposed EAL changes for the William B. McGuire Station, Units 1 and 2, are consistent with the guidance in NUMARC/NESP-007, with variations as identified and accepted in this

- review, and, therefore, meet the requirements of 10 CFR 50.47(b)(4) and Appendix E to 10 CFR Part 50.

The acceptance of the proposed EALs is contingent on the licensee discussing and obtaining an agreement from the offsite authorities before implementation .

I Principal Contributors: W. Maier L.K. Cohen Date: January 28, 1998

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