ML20134D106
| ML20134D106 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 01/27/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20134D093 | List: |
| References | |
| NUDOCS 9702040302 | |
| Download: ML20134D106 (10) | |
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g & UNITED STATES
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j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20066-00(H o
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ON REVISED EMERGENCY ACTION LEVELS FOR CENTERIOR ENERGY'S PERRY NUCLEAR POWER PLANT DOCKET N0. 50-440 l
1.0 INTRODUCTION
By letter dated February 16, 1996, as supplemented by letters dated September 27, 1996, and December 23, 1996, Cleveland Electric Illuminating Company (the licensee) submitted proposed changes to the Perry Nuclear Power Plant emergency action levels (EALs) developed in accordance with NUMARC/NESP-007 guidance. Specifically, the licensee provided a proposed revision to the Perry Nuclear Plant " Emergency Action Level Basis Document," and documentation justifying site-specific EAL thresholds and deviations from the NUMARC/NESP-007 guidance. The Emergency Action Level Basis Document included the site-specific initiating conditions (ICs), EALs, and basis for the ICs and EAls.
The licensee intends to revise its emergency plan and emergency plan implementing procedures to incorporate the ICs and EAls following NRC's approval of these ICs and EALs.
2.0 BACKGROUND
The proposed revision to the Perry EALs was reviewed against the requirements in 10 CFR 50.47(b)(4) and Appendix E to 10 CFR Part 50.
10 CFR 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 not only on onsite and offsite radiation monitoring information but also on readings from a number of sensors that indicate a potential emergency, such 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."
i In Revision 3 to Regulatory Guide 1.101, " Emergency Planning and Preparedness i for Nuclear Power Reactors," the NRC endorsed NUMARC/NESP-007, Revision 2, I " Methodology for Development of Emergency Action Levels," as an acceptable l method for licensees to meet the requirements of 10 CFR 50.47 (b)(4) and i Appendix E to 10 CFR Part 50. The staff relied upon the guidance in l
PERRY NUCLEAR PLANT 1 9702040302 970127 PDR ADOCK 05000440 F PDR
NUMARC/NESP-007 as the basis for its review of the Perry EAL changes.
3.0 EVALUATION Most of the proposed EALs conformed closely to the guidance. However, some of the licensee's proposed EAls deviate from the example EALs in NUMARC/NESP-007.
In addition, the licensee included a number of EAls not specified in NUMARC/NESP-007. The staff's evaluation of these variations is discussed below.
Deviation #1 Modified Basis for Setpoint for Release Monitor EAL The Perry Unusual Event EAL for the release of gaseous radioactive material is set at 140% technical specification values instead of the 200% specified in the NUMARC/NESP-007 guidance. The use of the 140% allows for the use of a multiple of the alarm setpoint for the monitor and therefore is readily i observable. Release of gaseous radioactive material at a level of 140% of the technical specification limit is a valid indication of the loss of control of the release of radioactive material which is the basis for this EAL.
Similarly, the Perry Alert EAL for the release of gaseous radioactive material is set at 140 times technical specification values instead of the 200 times specified in the NUMARC/NESP-007 guidance. These deviations are acceptable.
Deviation #2 Fission Product Barrier -- Loss of Fuel Clad as Indicated by Water Level The NUMARC/NESP-007 EAL for the loss of the fuel clad barrier based on reactor vessel water level indications is:
Level LESS THAN (site-specific) value The corresponding Perry EAL is:
d Entry into PEI-T23, Containment Flooding s
PEI-T23 is entered if any of the criteria below CANNOT be met:
Under non-anticipated transient without scram (non-ATWS) conditions, Reactor Pressure Vessel (RPV) water level cannot be restored and q maintained above top of active fuel with the RPV depressurized.
Under non-ATWS conditions, RPV water level cannot be maintained above minimum steam cooling RPV water level (-42.5 inches) with the RPV pressurized.
RPV water level cannot be determined and RPV flooding conditions cannot be established and maintained.
Under ATWS conditions, RPV water level cannot be maintained above minimum zero injection RPV water level (-25 inches)
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Each of these conditions is indicative of the loss of adequate core cooling which would lead to fuel clad damage. The use of the emergency operating procedure (E0P) threshold is beneficial because it accurately defines the condition of concern and is familiar to plant operators. One drawback with the use of this threshold is that it may cause a slight delay in classification because operators will have to progress through the E0Ps to the point where entry into containment flooding is required. However, other EALs are_ available for identifying the potential loss or loss of fuel clad (including an EAL for the potential loss of fuel clad based upon water level at the top of active fuel) in the interim, while the E0Ps are being stepped through. Therefore, this deviation is acceptable.
Deviation #3 Fission Product Barrier -- Loss of reactor coolant system (RCS) barrier as indicated by main steam line break .
I A NUMARC/NESP-007 EAL for the loss of the reactor coolant system barrier based on reactor coolant leak rate is:
(site-specific) Indication of Main Steanline [MSL] Break l l
The corresponding Perry EAL is:
MSL break outside Containment exceeding one or more MSIV [ Main Steanline Isolation Valve] Tech. Spec. isolation setpoints and Containment penetration does M isolate on a valid closure signal and Innediate operator actions in the Control Room are M successful in isolating affected penetration.
The Perry EAL deviates from the NUMARC/NESP-007 EAL by including the additional conditions that: (1) the MSL break is of a magnitude which exceeds the technical specification isolation setpoint, and (2) the MSIV fails to ;
isolate.- This prevents inappropriate classification for small MSL lesh and '
prevents unwarranted classification if the MSIVs are immediately isolated.
Therefore, this deviation is acceptable.
Deviation #4 Fission Product Barrier -- Loss of RCS as indicated by RCS leakage One of the NUMARC/NESP-007 EALs for the. loss of the reactor coolant system barrier based on reactor coolant system leakage indications is:
RCS leakage greater than 50 gpa inside the drywell The licensee stated that they did not include this EAL because control room instrumentation cannot be used to adequately assess a 50 gpm instantaneous threshold. The licensee included an EAL based upon drywell pressure (greater than 1.68 psig) which the licensee has determined would be exceeded for about a 50 gpm RCS leak into the drywell. This deviation is acceptable.
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Deviation #5 Fission Product Barrier -- Loss of RCS as indicated by Drywell Pressure The NUMARC/NESP-007 EAL for the loss of RCS as indicated by drywell pressure is the drywell pressure alarm setpoint. The licensee deviated from this guidance by utilizing the drywell pressure scram setpoint. The licensee states that the alarm setpoint is set low enough to allow operator action to reduce containment pressure with containment cooling systems and is not intended to be the threshold of a loss-of-coolant-accident (LOCA). The scram setpoint is indicative of a LOCA and therefore is used as the threshold for this EAL. This deviation is acceptable.
Deviation #6 Fission Product Barrier -- Loss of Containment based upon Drywell Pressure NUMARC/NESP-007 EALs for the loss of the containment barrier based on d ywell pressure include:
Rapid unexplained decrease following initial increase Drywell pressure response not consistent with LOCA conditions The Perry EAL scheme did not included the first of these EALs as a stand alone EAL but rather included it under the envelope of emergency coordinator judgement. This deviation is acceptable.
The Perry EAL did not include the second of these EALs because, in the opinion of the licensee, the indication is too vague for the Emergency Coordinator to analyze and implies that the LOCA response for Containment will follow a pre-analyzed response time. The licensee states that Emergency Coordinator judgment is still available if technical support center engineers do not believe that Containment is performing as designed. This deviation is acceptable.
Deviation #7 Fission Product Barrier -- Loss of Containment based upon Isolation Failure The NUMARC/NESP-007 EAL for the potential loss of the containment barrier based on containment isolation is:
Failure of both valves in a y c,u line to close AND Downstream pathway to the environment exists The correspondirig Perry EAL is:
Containment penetration does $1 isolate on a valid closure signal AND l Immediate Operator action in the Control Room are NOT successful in l isolating affective penetration AND l Pathway to then environment exists via penetration' PERRY NUCLEAR PLANT 4 l
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2 l Pathway exists through a break or systen penetration which would in l
effect bypass Containment creating a pathway to the environment outside the normal process stream or with normal filtration @T intact i
This EAL deviates from the NUMARC/NESP-007 guidance by defining what
- constitutes a " Pathway to the environment" as the conditions described in i footnote 2. It is inappropriate to define the loss of the containment barrier j in this manner because, even if the normal process stream or normal filtration
- is intact, a release of radioactive material which may affect the environment
- could occur. This EAL would be acceptable if the footnote for this EAL and 1 the corresponding definition in the basis for this EAL are eliminated.
Alternatively, the licensee eav provide additional justification for this deviation or submit a revised EAL Sr NRC approval.
i Deviation #8 Fission Product Barrier -- Potential Loss of j Containment based upon RPV level The NUMARC/NESP-007 EAL for the potential loss of the containment barrier
! based on RPV level is:
1 i Reactor vessel water level LESS THAN (site-specific) value and the maximun 1
core uncovery time limit is in the UNSAFE region The corresponding Perry EAL is:
Entry into PEI-T23 Containment Flooding and is used as an indication of the loss of containment (rather than potential loss as in NUMARC/NESP-007).
The licensee stated that it did not include the NUMARC/NESP-007 EAL because ;
the NUMARC/NESP-007 EAL is not an appropriate indication of core damage. The NUMARC/NESP-007 EAL is based upon a curve which is applir.able under conditions where RPV water cannot be determined. Furthermore the iicensee stated that the assumptions used in deriving the curve are not consistent with various plant conditions which may exist when the EAL is being applied.
The licensee chose instead to use the indication of entry into the containment flooding procedure for this EAL. As described previously under Deviation #2, this entry condition is based upon the loss of adequate core cooling and i therefore is indicative of the potential for a large degree of core damage. '
In addition, the entry into this E0P is accompanied by the opening of the Containment vent which would cause the bypass (i.e. loss) of the containment barrier. Therefore this EAL is acceptable. '
Deviation #9 Fission Product Barrier -- Potential loss of Containment on explosive mixture The NUMARC/NESP-007 EAL for the potential loss of the containment barrier based on explosive concentration is:
Explosive afxture exists PERRY NUCLEAR PLANT 5
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3 I The corresponding Perry EAL is:
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Intentfonal venting of Containment required per PEI-M51/M56 .
l and is indicative of the loss, rather than potential loss, of containment.
l The licensee states that intentional venting per PEI-M51/M56 is required at the combustible gas limits and therefore this EAL threshold is equivalent to l the NUMARC/NESP-007 EAL (but is indicative of the loss of containment due to i the intentional venting which occurs). This deviation is acceptable.
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Deviation #10 Toxic or Flammable Gas EAL l The NUMARC/NESP-007 guidance specifies the following EAL under IC HU3:
i Report or detection of toxic or flannable gases that could enter within j the site area boundary in amounts that can affect normal operation of the l plant.
! The corresponding Perry EAL (MUI) deviates from NUMARC/NESP-007 EAL HU3 by i restricting the applicability of the EAL to the protected area boundary '
! instead of the site area boundary. The justification for this deviation is
- that releases that do not affect the protected area would not impact normal
- operation of the plant. This deviation is acceptable.
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- Deviation #11 NUMARC/NESP-007 EAL SUS RCS Leakage l The NUMARC/NESP-007 guidance specifies the following EAL under IC SU5
The following conditions exist: j i
l a. Unidentified or pressure boundary leakage greater than 10 gpa.
1 OR
- b. Identified leakage greater than 25 gpa. ;
The corresponding Perry EAL is:
Greater than 10 gpn unidentified leakage in Drywell or Greater than 30 gpa total leakage in Drywell averaged over the previous 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period or Greater than 30 gpn total leakage in Drywell and greater than 2 gpn increase in unidentified leakage within the previous 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period The Perry EAL deviates from the NUMARC/NESP-007 guidance by specifying different limits for identified leakage and not including an EAL for pressure i boundary leakage. The licensee states that pressure boundary leakage is equivalent to unidentified leakage in accordance with the Perry technical specification. Furthermore, the licensee states that the use of the 30 gpm limit averaged over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in conjunction with a 2 gpm increase is consistent with the Perry technical specifications and is an appropriate PERRY NUCLEAR PLANT 6
threshold for indication of the potential degradation in the level of safety !
of the plant. This deviation is acceptable. 1 Deviation #12 ATWS EAL The NUMARC/NESP-007 guidance specifies the following EAL under IC SS2:
(Site-specific) indications exist that automatic and manual scram were not successful The corresponding Perry EAL is:
Following automatic actuations of either of the following " shutdown under all conditions without baron" has ap1 been obtained:
- RRCS and
- 1. Manual operator actions taken at 1H13-P680 to insert control rods were NOT successful in lowering Reactor power to less than 4% or
- 2. Reactor Power CANNOT be determined or ,
- 3. Suppression Pool temperature is greater than 110 *F 1
The licensee states that the last three conditions of this EAL provide readily apparent indication of a situation where the reactor is producing more heat than the maximum decay heat load for which the safety systems are designed.
This is consistent with the basis for the corresponding NUMARC/NESP-007 EAL and, therefore this EAL is acceptable.
Deviation #13 EAL for Loss of Function to Achieve Hot Shutdown The NUMARC/NE.c?-007 guidance specifies the following IC and EAL under IC SS2:
Complete loss of function needed to achieve HOT SHUTDOWN
- 1. Complete loss of any (site-specific) function required for hot shutdown The corresponding Perry IC and EAL are:
Complete loss of function needed to achieve COLD SHUTDOWN RHR Loops A and B are NOT capable of lowering RPV temperature and Suppression Pool temperature is above the HCL The Perry IC deviates by referencing the inability to achieve sqld shutdown rather than the inatility of achieving hot shutdown. The licensee justified this deviation by noting that for a BWR, entering Hot Shutdown merely requires placing the reactor mode switch in shutdown. The PERRY NUCLEAR PLANT 7
NUMARC/NESP-007 guidance addresses complete loss of functions, including heat removal and reactivity control. The licensee's EAL is indicative of the complete loss of the decay heat removal function. The licensee has a separate EAL which covers the loss of reactivity control. This EAL meets the intent of the NUMARC/NESP-007 guidance and therefore is acceptable.
Deviation #14 NUMARC/NESP-007 EAL SS5 Loss of Water Level The NUMARC/NESP-007 guidance includes the following EAL under IC SS5 (applicable in Cold Shutdown, and Refueling modes):
Loss of RPV water level ndicated by:
loss of all decay heat removal cooling as indicated by (site-specific) procedure and (site-specific) indication that the core is or will be uncovered The corresponding Perry EAL (which is applicable in Power Operations, Start Up, Hot Shutdown, Cold Shutdown, and Refueling modes) is:
RPV water level CANNOT be maintained greater than 0" AND Reactor is " shutdown under all conditions without boron" The licensee deviates from the NUMARC/NESP-007 guidance by: (1) not including the condition of " loss of all decay heat removal cooling as indicated by (site-specific) procedure," (2) including the condition " shutdown under all conditions without boron," and (3) being applicable in three additional modes of ooeration. The licensee did not include the condition " loss of all decay heat removal cooling as indicated by (site-specific) procedure" because the inability to keep the core covered is, in itself, a loss of decay heat removal cooling capability. The licensee expanded the mode applicability to ensure consistency with the Fission Product Barrier matrix for declaration of a Site Area Emergency based upon RPV level. The licensee included the condition
" shutdown under all conditions without boron" because RPV level is intentionally lowered during an ATWS to reduce power level in accordance with plant procedures and the licensee's EAL scheme includes an EAL which specifically addresses ATWS conditions. These deviations are acceptable.
Site-soecific Addition #1 Radioactive effluent monitor EAL The Perry EAL scheme included the following EAL under the IC "Any Unplanned Release of Gaseous Radioactivity to the Environment that Exceeds 200 Times ODCM Control Limit for 15 Minutes or Longer:"
Portable survey instruments indicated radiation levels of greater than 10 mrem /hr at the Site Boundary for greater than or equal to 15 minutes This EAL was not specified in the NUMARC/NESP-007 guidance but is an PERRY NUCLEAR PLANT 8
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i appropriate indication of the initiating condition. Therefore, this EAL is
. acceptable, o
Site-soecific Addition #2 Fission Product Barrier -- Potential Loss of Fuel Clad based on Water Level The Perry EAL scheme includes the EAL "RPV level cannot be determined" as a site-specific EAL for the potential loss of the fuel clad barrier. This was
- not included in the NUMARC/NESP-007 scheme. The licensee states that when the
. RPV water level cannot be determined, the plant operators are directed to
, attempt to establish RPV flooding conditions with the assumption that RPV 5
water level is below the top of active fuel, and therefore, this condition is l consistent with the fuel clad challenge criteria. This site-specific EAL is i j acceptable. !
l I i i Site-soecific Addition #3 Fission Product Barrier -- site specific !
i addition for loss of RCS j
! The Perry EAL scheme included the following site-specific EALs for the loss of j the RCS barrier:
A. SRV stuck open or an SRV is being cycled to control RPV pressure AND
, Sample activity is equal to or greater than 300 pCi/gm dose equivalent Iodine-131 4
B. Emergency Depressurization is required
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i The first of these EALs is indicative of the bypassing (unintentionally in the case where the SRV is stuck open or intentionally if the SRV is being cycling)
{ of the RCS with fuel damage. This condition is in indicative of the loss of i two fission product barriers. This EAL is used as indication of the loss of the RCS barrier and an EAL based upon 300 pCi/gm dose equivalent iodine-131 is used as an indication of the loss of the fuel clad barrier EAL. Therefore, 4
this site-specific EAL is acceptable.
The second of these EALs " emergency depressurization is required" is l
. indicative of the loss of the RCS because the E0P for performing the i intentional depressurization specifies that the SRVs should remain open until ,
- the emergency no longer exists. Therefore, this site-specific EAL is acceptable.
. Site-soecific Addition #4 Fission Product Barrier -- Site-specific addition for potential loss of Containment i The licensee added the following EAL as a site-specific indication of the 3
potential loss of the containment barrier.
f In the UNSAFE region on the HCL figure Entry into the UNSAFE region indicates that the suppression pool temperature is above the heat capacity temperature limit or below the heat capacity level j PERRY NUCLEAR PLANT 9
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limit. Either of these conditions are indicative of an increased potential '
for the loss of containment during an event. Therefore the addition of this i
EAL as an indication of the potential loss of containment is accaptable.
Site-soecific Addition #5 High Winds Unusual Event EAL -
The Perry EAL scheme included the following site-specific Unusual Event EAL under the IC of Natural and Destructive Phenomena Affecting the Protected Area:
High sustained winds greater than 70 mph for equal to or greater than 15 minutes .i The licensee states that high sustained winds in excess of 70 mph is a potentially destructive phenomenon that may accompany certain events such as a tornado, hurricane, or unstable weather conditions and represents a potential degradation in the level of safety of the plant. Therefore, declaration of an Unusual Event for this type of event is appropriate. This site-specific EAL ;
is acceptable.
l Site-soecific Addition #6 Internal Flooding EAL The Perry EAL scheme included the following site-specific Alert EAL under the IC " Natural and Destructive Phenomena Affecting the Protected Area:"
l Greater than PEI-N11 Maximun Safe Operating Value for Area Water Level (internal flooding)
The licensee states that the Maximum Safe Operating Value for Area Water )
Level, as defined in PEI-N11, is used to quantify the magnitude and i significance of plant internal flooding and is based on equipment qualification. Internal flooding which may effect equipment operability represents a potential substantial degradation of the level of safety of the plant. Therefore this site-specific EAL is acceptable.
4.0 CONCLUSION
With one exception the proposed EAL changes for the Perry Nuclear Power Plant 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 exception is the EAL for the loss of the containment barrier as indicated by failure of a containment penetration to isolate with existence of a pathway to the environment. This EAL includes a footnote (number 2) which indicates that the containment is not considered lost if the pathway is to the environment is I through the normal process stream or with normal filtration intact. The staff l considers this footnote to be an inappropriate deviation from the NUMARC/NESP-007 guidance. Removal of this footnote will make the EAL acceptable.
Alternatively, the licensee may provide additional justification for this deviation or submit a revised EAL for NRC approval.
Principal Contributor: J. O'Brien, PERB/NRR Date: January 27, 1997 PERRY NUCLEAR PLANT 10