ML20199A642
| ML20199A642 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 01/22/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20199A627 | List: |
| References | |
| NUDOCS 9801280042 | |
| Download: ML20199A642 (8) | |
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60 88c p$ t UNITED STATES
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REVISED EMERGENCY ACTION LEVELS DUKE L'ej *RGY CORPORATION CATAWBA NUCLEAR STAllON. UNITS 1 AND 2 i i
DOCKET NOS. 50-413 AND 50-414 l
1.0 INTRODUCTION
By letter dated August 29,1996, as supplemented by letters dated March 29 and !
October 21,1997, Duke Energy Corporation (formerly Duke Power Company, the licensee) proposed changes to the Catawba Nuclear Station emergency action levels (EALs) in order to implement the NUMARC/NESP 007 EAL methodology. Specifically, the licensee provided the following documents in the original August 29,1996, submittal: a revision to Catawba procedure RP/0/A/5000/01, " Classification of Emergency," which listed the EALs and included guidelines l for using the EALs to declare an emergency condition; a revision to Section D of the Catawba 1 Emergency Plan, " Emergency Classification System," which provided a basis for each of the EALs and described how the proposed EALs incorporated the industry guidance in NUMARC/NESP 007," Methodology for Development of Emergency Action Levels,' Revision 2, dated January 1992; and a disposition of NUMARC/NESP-007, Revision 2, initiat.ng conditions and EALs in the Catawba EAL submittal, which provided a cross reference between the NUMARC EALs and their equivalents under the Catawba EAL numbering scheme. The NRC has endorsed NUMARC/NESP-007 as an acceptable method by which licensees may develop site-specific emergency classification schemes.
The licensee also provided letters from the State and local governmental authorities in the Catawba emetgency planning zone (EPZ), indicating that those authorities had reviewed and regreed with the EALs contained in the !icensee's August 29,1996, letter to NRC.
In response to the staffs January 14,1997, request for additional information (RAI) conceming the original submittal, the licensee supplemented the original submittal with additional information. This information was submitted by the licensee to NRC by letter dated March 29, 1997. The submittalincluded a written response to the issues raised in NRC's RAI and revisions to the above mentioned documents to address issues raised in NRC's RAI.
The March 29,1997, response to NRC's RAI did not contain agreements from the State and loca! govemmental authorities to the changes. However, in its letter dated October 21,1997, the licensee committed to ensure that the EALs, as approved by NRC, would be discussed and agreed upon with the offsite govemmental au'horities in the Catawba EPZ before implementation.
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2-The October 21,1997, letter from tl.3 licensee contained additional information requested by the NRC after its review of the licensee's response dated March 29,1997. The request for this additional information was discussed with the licensee in t. June 23,1997, teleconference.
2.0 BACKGROUND
The staff reviewed the revision to the Catawba Units 1 and 2 EAls against the requirements of 10 CFR 50.47(b'(4); and Appendix E to 10 CFR Part 50. The staff did not review the proposed revision to the Catowba emergency plan and classification procedure against the previously !
approved emergency p'an to determine whether the changes to these documents, not )
specifically related to the content of the EAls, ccnstituted a decrease in the effectiveness of the !
plan as described !n 10 CFR 50.54(q). Any review or approval of these documents not related to EAL content it outsi:le the scope of this safety evaluation.
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 the nuclear facility licensee...." )
Appendix E (IV)(C) specifies that " emergency action levels (based nt,t only on onsite and offsite ;
radiation monitoring information but also on readings from a number of sensors that indicate a ;
potential emergency, tuch as pressure in containment and response of the emergency core ,
cooling system) for notification of offsite agencies shall be described....The emergency classes '
defined shall include (1) notification of unusual events, (2) alert, (3) site area emergency, and (4) general emergency."
In Revision 3 to Regulatcry Guide 1.101, " Emergency Planning and Preparedness for Nuclear Power Reactors," the 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 Catawba EAL changes.
3.0 EVALUATION The licensee documented the emergency classification system in Section D of the Catawba Emergency Plan and in Enclosures 4.1 through 4.7 of Catawba Procedure RP/0/A/5000/01,
" Classification of Emergency."
The classification system follows the NUMARC guidance closely. The EAls are divided into seven categories as listed below:
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4.1 Fission Product Bemer Matrix j 4.2 System Malfunction ;
4.3 Abnormal Rad Levels / Radiological Effluent i
.4.4 Loss of Shutdown Function l 4.5 Loss of Powcr i 4'
- 4.6 Fire / Explosion and Security Events- .
4.7 ~ Natural Disasters, Hotsrds, and Other Conditions Affecting Plant Safety Each category lists the four classes of emergency, notification of unusual event (UE), siert, site 1 i
area emergency (SAE), and general emergency (GE). Under each class of emergency are l 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/5000/01 lists the operating mode (s) or plant condition for which each IC is applicable. Procedure RP/0/AiS000/01 also lists EALs under each IC for use by the :
classifying official, in order to compare the EAL to the plant parameters observed for ease of 1-classification. l t
- 1echnical bases for each of the EALs are contained in Section D of the Catawba Emergency i I
Plan. These bases are separated by category. Each page of the technical basis document contains an 1C, its applicable operating mode (s), the EALs that satisfy the IC, bases for.each EAL under the particular IC, and a NUMARC reference IC from which the Catawba IC is ' ;
derived.
l The licensee reviewed the revised EALs with the offsite authorities in the Catawba plume
. exposure EPZ and provided concu rence letters from these agencies, which indicated the ,
offsite agencies' approval of the proposed EALs.
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 i scooptable, e NUMARC ICs AU1 and AA1 contain EALs that require the performance of offsite .. ->
assessments of releases of radioactive materials. The licensee did not include provision for performing these assessments in its original submittal, because the licensee did not haive an on-shift dose assessment capability at the time of the' original submittal in its ;
response to the RAI, 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 m
that it did not intend to implement the submitted EAL methodology until that capability had beert restored.'.On August 4,1997, the licensee submitted Revision 97 3 to the Catawba
- Nucisar Site Emergency Plan effective August 1,1997, which augmented the capability ,
' for on shift dose asser,sment. Since the licensee now has on-shift dose assessment .
capabiMy for the. accurate determination of the declaration thrssholds for Catawba EALs
- 4.3 U.1 1,4.3.U.1 2,4.3.A.1 1, and 4.3A12, these EALs are acceptable, t
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- e NUMARC ICs AU1 and AA1, and their associated EALs, describe emergency conditions t i 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. Catawba ICs 4.3.U.1 and 4.3.A.1 and their associated EALs !
refersMe release rate thresholds as multiples of selected licensee commnments (SLCs).
The use of these SLCs is an acceptable attemative to the Rodological Technical Specifications as permitted in NRC Generic Letter No. 89-01 and Catawba license ,
l Amendment Nos.103 (Unit 1) and 97 (Unit 2), dated December 9,1992. j i
- - NUMARC EAL AU1.3, AA1.3, AS1.2, and AG1.2 provide for declaration of emergency conditions based on telemetered site perimeter radiation monitors. The Catawba EAL i scheme does not include these EALs since the site does not have this type of monitor. !
Since the MUMARC guidance does not require these EALs for plants that do not have !
, telemetered site perimeter monitors, this omission is acceptable. -i l
e NUMARC EALs AU1.4 and AA1.4 provide for UE and alert declarations, respectively, i based on uncontrolled releases of gaseous or liquid effluent that exceed threshold values i L as read on the automatic real time dose assessment capability. The Catawba EAL scheme does not contain equivalent EALs to these NUMARC examples, because !
Catawba does not contain any such automatic real-time dose assessment capability. l Since the NUMARO guidance does not require these EALs for sites not having such .
i capability, this deviation is acceptable. l t
o NUMARC EAL AU2.3 provides for the declaration of a UE for an unexpected increase in radiation levels surrounding irradiated spent fuel in dry storage. Since the Catawba
, station has no dry spent fuel storage facility, it does not include this EAL in its scheme.
This is an acceptable deviation from the NUMARC guidance.
i e . NUMARC EAL AU2.4 provides for a UE declaration for valid direct area radiation l readings in the plant that reflect an incrosse (by a factor of 1000) ov6r normal levels. ;
3 Catawba EAL 4.3.U.2-3 modified the NUMARC guidance by roouiring the increase in l radiation levels to be unplanned" for the EAL to be met. This deviation is acceptable !
since the NUMARC guidance, in its basis for this EAL, addresses the fact that these
- radiation level increases are assumed to be unplanned in nature. >
' observed to be uncovered.- Catawba EAL 4.3.A.2 2 is listed as equivalent to NUMARC ;
- EAL AA2.2, but Catawba EAL 4.3.A.2 2 deviates from the NUMARC example by- i recognizing conditions that will result in imminent fuel uncovering rather than the AGhial :
uncovering of irradiated fuel. - The basis for the Catawba EAL states that personnel :
observing such conditions should not remain in Wort conditions until the fuel is actually C - uncovered. Although the wording of the Catawba EAL increases the subjectivity of this :
' declaration, since it is not tied to an easily observable condition, it ensures a more conserve,tive approach to the declaration of this EAL and greater personnel safety,- ~
Therefore, this deviation is acceptable.
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e AA3,3/4.3.A.3-3 How To Determine if EAL is Exceeded i e NUMARC ICs AS1 and AG1 and their associated EALs describe emergency conditions l for release of radioactive material that yields exclusive area boundary doses that ,
approach or exceed Environmental Protection Agency (EPA) protective action guides. !
The NUMARC dose criteria are based on doses to the whole body or child thyroid and ;
expressed in units of milliR6entgen. The Catawbs EALs equivalent to these NUMARC l examples have revised these doses to incorporate the dose equivalents that are listed in :
s the revised EPA and 10 CFr Part 20 methodologies for dose calculations. These new methodologies consider bott, the extemal and intomal contributions to radiological dose. ,
The Catt vba EALs list total effective dose equivalent (TEDE) for the whole body and ;
committed dose equivalent for the adgli thyroid. The dose units referenced in the l Cata%s EALs are in mrom TEDE. Because the new EPA methodology is based on protective action guides for ti.c general population, the Catawba EAL use of adult thyroid is acceptable. Because the revised methodologies recognizing effective dose equivalents ,
is considered an improvement over previous methodologies, the Catawba EAL use of i TEDE is also approved, e AS1.1, AG1.1/4.3.8.11,4.3.G.M Source Term Assumptions )
e The Catawba EAL submittal has a fission product barrier matrix that closely follows the NUMARC example. One deviation noted is the use of a point system for equating the status of the barriers with an emergency classification level. The Catawba matrix assigns various point values to EALs that describe conditions challenging the three fission product barriers (fuel cladding, reactor coolant system, and primary containment). The point
' values vary according to the specific barrier affected and whether the condition constitutes a loss or potential loss of that barrier, The points corresponding to the most :
serious challenge to each barrier are added together and the point total determines the i classification level. The point total methodology yields results consistent with the
- NUMARC guidance. Its use is acceptable.
=e The NUMARC fission product barrier matrix recognizes several conditions that constitute
. a loss of the fuel cladding barrier. One of these is based on core exit thermocouple .
readings and another is based en status of the core cooling critical safety function status
.. tree (CSFST), which in tum, is based on, among other parameters, core exit -
thermocouple readings. The inclusion of both of ti,ese EALs it redundant in plants using CSFSTs in their emergency operating procedures. Catawba is one such plant.. .
Consequently, it has eliminated the EAL dealing with core exit thermocouple readings ,
alone. This deviation is acceptable.
.e The NUMARC fission product barrier matrix also has multiple EALs that address a i potential loss of the fuel cladding barrier. .One such EAL is based solely on reactor..
t-vessel water level, and another EAL is based on the core cooling CSFST, which is, in
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6-turn, based on reactor vessel water level. Thase EALs are redundant for Catawba, which )
uses CSFSTs in this emergency operating procedures. Becaese of this redundancy, Catawba has eliminated the EAL solely on the basis of reactor vessel water level. This deletion is acceptable. I
- NUMARC EAL PC6, whico recogrites a potentialloss of the primary containment barrier, l Is expressed in terms of core exit thermocouple readings and reactor vessellevel. These l Indications are that which satisfy the 'rea path
- condition 1 y the core cooling CSFST.
The Catawba fisr'on product barrier matrix recognizes a red path condition in core cooling as utisfying 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.
o NUMARC EAL RC3, in the fission product barrier matrix, recognizes a potentialloss of the reactor coolant system (RCS) barrier for primary to-secondary leakage that exceeds the capac;ty of one charging pump in the normal charging mode. Catawba EAL 4.1.N.3, which correspands to this NUMARC 3xample, includes the additional requirement that letdown is isolated for the EAL to be met. This is an acceptable deviation to the NUMARC guidance, since it is normal orocedure for operators to isolate the letdown flow from the RCS as part of diagnois or "esponse to any RCS leak. The Catawba basis i provides for considering the EAL satsfied if letdown cannot be isolated, but all other conditions are met. This deviation is acceptable, o NUMARC EAL RC4, in the fission product t,arrier matrix, recognizes a loss of the RCS barrier in cases in which the contt 'nment radiation monitor channels exceed a site.
specific threshold. The Catawba thslon product barrier matrix does not contain a corresponding EAL, because the Catawba containment monitors that would be available to detect this condition are designed so that they wouk. Le insensit!ve to a loss of the RCS barrier with normal RCS activity.1 he NUMARC guidance for this particular EA!.
recognizes this possible condition and recommends omitting this EAL from the site-specific matrix in these cases This deviation is acceptWe.
e NL MARC EAL HU1.3 recognizes control room personnel assessment of a natural or de;tructive event .(fecting the protected area of the plant as an unussual event (UE).
The Catawba EAL scheme recognizes this NUMARC EAL as redundant to NUMARC EAL HUS.1, which allows declaration of a UE based on the emergency director judgment.
Since the emergency 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 Catawba submittalis acceptable.
- NUMARC EAL HU4.2 allows for security events, not already covered by the NUMARC guidance, to be included in site-specific EAL submittals for declarat!on of a UE. The Catawba submittal includes two additional EAls, 4.6.U.2-2, which recognize a hostage
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. 7 l or extortion situation, and 4.6.U.2 3, which recognize a violent civil disturbance within the i 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 :
i declaration, and their inclusion into the Catawba EAL scheme is acceptable.
j 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 1
shutdown for all operating modes (including the defueled condition). Catawba has t
! divided this 10 into two separate ICs: 4.6.A.1, applicable in modes 16, and 4.6.A.2, l applicable in the defueled condition. This deviation is acceptable because the j
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oomplement of equipment needed to maintain a safe-shutdown condition while defieled is much less than that needed to maintain a safe shutdown condition in the other modes. .
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, - degraded electrical power supply to essential buses. These EALs list loss of power to certain site specific transformers as une condition leading to declaration of the emergency conditions associated with them. The corresponding Catawba EALs do not list any site specific transformers, but rather list the essential bugs that are affected. l l Since listing the specific buses is a more direct method of determining the status of '
L electrical power to them, this deviation la acceptable.
i e NUMARC IC SU1, which is listad as applicable in all operating modes, recognizes an UE f condition for a loss of all offsite power to the esserWal buses. The single EAL for this IC
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~ requires both the loss of the offsite power supplies and the startup and loading of the diesel generators to supply those buses. The Catawba submittal divides this NUMARC
! example IC into two EALs with different applicable modes of operation for each: 4.5.U.1 1 i for operating modes 1-4 and 4.5.U.12 for modes 5,6, and the defueled condition. EAL-l 4.5.U.1 1 requires both diesel generators to start and supply the essential buses; 5AL 4.5.U.12 only requires one diesel generator to supply its respective emergency bus.
1 l This deviation is acceptable since the operatsility of only one essential bus is consistent i with the Techn8 cal Specification requirements for the operating modes for which EAL 4.5.U.12 is applicable.
e- NUMARC EAL SU1.1 recognizes site-specific radiation monitor readings as indicators of <
fuel cladding degradation greater than technical specification limits. There is no
, comparable EAL in the Cataea submittal, since the plant has no such failed fuel monitor. This deletion from the Catawba EAL submitta' is acceptable, i-e NUMARC EAL SU4.2 recognizes site specific levels of reactor _ coolant activity as measured by sample as indicators of fuel cladding degradation greater than technical specification limits.. Catawba EAL 4.2.U.3-1 is listed as equivalent to this NUMARC EAL.
Although the NUMARC EAL IC SU4 is listed as applicable in "All" operating modes, 7 Catawba IC 4.2.U.3 is only listed as applicable in modes 15. The refueling condition
- (Mode 6) and the defueled condition are not included in the Catawba IC. This is because r L there is no technical specification limit for coolant activity in either ef these conditions.
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. Catawba scheme contains ICs and EALs for all credible events in these operating conditions which, in time would trigger either equivalent or higher classifications than l
< 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 Catawba !C to en acceptable deviation the NUMARC guidance. !
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e NUMARC lC SS4 recognizes an SAE condition for the complete loss of any function required for achieving or maintaining a not shutdown condition. The NUMARC guidance ;
allows for site-specific identification c4 these necessary functions, although the NUMARC -
basis lists such functions as reactMty control and the ultimate heat sink as those that ;
I sites should consider. Catawba !C 4.4.S.2, identified as equivalent to NUMARC IC SS4, i
lists the CSFSTs of suberiticalny and heat sink as the functions whose loss satisfies the
! 10. The use of these CSFSTs, although not as explicit as the examples stated in the
!! NUMARC basis, represent conditions that meet the intent of the NUMARC guidelines and i is easily recognized by control room operators and managers. Therfore, the use of these ;
CSFSTs for this IC is acceptable.
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!. warranting a GE declaration. Catawba EAL 4.5.G.1 1 has modified this EAL by adding l 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 !
i safety functions associated with fssion product barrier integrity. Therefore, this additio,1
. to the EAL is acceptable divistion from the NUMARC guidance.
4.0 CONCLUSION
i The proposed EAL changes for the Catawba Nuclear Station Units 1 and 2 are conostent with the guidance in NUMARC/NESP-007, with variations as identN and accepted in this review, and, therefore, meet the requirements of 10 CFR 50.47(b)(4) i .d Appendix E to 10 CFR Part 50.
The acceptance of the proposed EALs is contingent on the licensee discussing and obtaining ;
en agreement from the offsite authorities before implementation.
Principal Contributors: William A. Maier Lawrence K. Cohen Dated: January 22,1998 1
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