ML20216G886
| ML20216G886 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 04/15/1998 |
| From: | Pickett D NRC (Affiliation Not Assigned) |
| To: | Myers L CENTERIOR ENERGY |
| References | |
| TAC-M83659, NUDOCS 9804200519 | |
| Download: ML20216G886 (11) | |
Text
.e April 15, 1998 Mr. Lew W. Myers DISTRIBUTION:
Vice President - Nuclear, Perry PUBLIC PDlll-3 R/F Centerior Service Company BBoger EAdensam P.O. Box 97, A200 RSavio ARubin, RES Perry, OH 44081 GGrant, R3
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION P.EGARDING IPEEE SUBMITTAL - PERRY NUCLEAR POWER PLANT, UNIT NO.1 (TAC NO. M83659)
Dear Mr. Myers:
The staff and its contractors have reviewed the Individual Plant Examination of External Events for Severe Accident Vulnerabilities (IPEEE) for the Perry Nuclear Power Plant, Unit No.1.
Based on our review, we have develcf el the enclosed requests for additional information (RAI). The RAls are related to the sei. iic and fire analyses in the IPEEE. There are no RAls for the review of high winds, flood, and other external events (HFO) in the IPEEE. The RAls in the seismic area were developed by our contractor, Brookhaven National Laboratory, and the RAls in the fire area were developed by our contractor, Sandia National Laborasories. All of the RAls were reviewed by the " Senior Review Board"(SRB). The SRB is comprised of RES and NRR staff and RES consultants (Sandia National Laboratories) with probabilistic risk assessment expertise in external events.
In order to best accomodate the review schedules for both the staff and contractors, we request that you provide a response within 60 days of receipt of this letter Sincerely, Original signed by:
Douglas V. Pickett, Senior Project Manager Project Directorate lil-3 Division of Reactor Projects - lil/IV Office of Nuclear Reactor Regulation Docket No. 50-440
Enclosure:
As stated cc: See next page DOCUMENT NAME: G:\\ PERRY \\PER83659.RAI To receive a copy of this document. indicate in the box: "C" = Copy without enclosures "E" = Copy with enclosures "N" = No copy 0FFICE PM:PDIII-3 LA:PDIII-3 6
NAME DPickett EBarnhill f7 (
DATE 04/85/98 04/)4/98 04/ /98 04/ /98 04/ /98 0FFICIAL RECORD COPY
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- k April 15, 1998 e
Mr. Lew W. Myers DISTRIBUTION:
Vice President - Nuclear, Perry PUBLIC PDill-3 R/F Centerior Service Company BBoger EAdensam P.O. Box 97, A200 RSavio ARubin, RES Perry, OH 44081 GGrant, R3
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDING IPEEE SUBMITTAL - PERRY NUCLEAR POWER PLANT, UNIT NO.1 (TAC NO. M83659)
Dear Mr. Myers:
The staff and its contractors have reviewed the Individual Plant Examination of External Events for Severe Accident Vulnerabilities (IPEEE) for the Perry Nuclear Power Plant, Unit No.1.
Based on our review, we have developed the enclosed requests for additional information (RAl). The RAls are related to the seismic and fire analyses in the IPEEE. There are no RAls for the review of hign winds, flood, and other external events (HFO) in the IPEEE. The RAls in the seismic area were developed by our contractor, Brookhaven National Laboratory, and the RAls in the fire area were developed by our contractor, Sandia National Laboratories. All of the RAls were reviewed by the " Senior Review Board"(SRB). The SRB is comprised of RES and NRR staff and RES consultants (Sandia National Laboratories) with probabilistic risk assessment expertise in external events.
In order to best accomodate the review schedules for both the staff and contractors, we request that you provide a response within 60 days of receipt of this letter i
i Sincerely, Original signed by:
Douglas V. Pickett, Senior Project Manager Project Directorate 111-3 Division of Reactor Projects - fil/IV Office of Nuclear Reactor Regulation Docket No. 50-440
Enclosure:
As stated cc: See next page DOCUMENT NAME: G:\\ PERRY \\PER83659.RAI To receive a copy of this document, Indicate in the box: *C* = Copy without enclosures *E* = Copy with enclosures "N* = No copy 0FFICE PM:PDIII-3 LA:PDIII-3 6
NAME DPickett EBarnhill f W DATE 04/85/98 04/l4/98 04/
/98 04/ /98 04/ /98 0FFICIAL RECORD COPY
,m
[4 UNITED STATES j
j NUCLEAR REGULATORY COMMISSION o
WASHINGTON, D.C. 20666 0001 4 *****,o 9
April 15, 1998 Mr. Lew W. Myers Vice President - Nuclear, Perry Centerior Service Company P.O. Box 97, A200 Perry, OH 44081
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDING IPEEE SUBMITTAL - PERRY NUCLEAR POWER PLANT, UNIT NO.1 (TAC NO. M83659)
Dear Mr. Myers:
The staff and its contractors have reviewed the Individual Plant Examination of External Events for Severe Accident Vulnerabilities (IPEEE) for the Perry Nuclear Power Plant, Unit No.1.
Based on our review, we have developed the enclosed requests for additional information (RAl). The RAls are related to the seismic and fire analyses in the IPEEE. There are no RAls for the review of high winds, flood, and other external events (HFO) in the iPEEE. The RAls in the seismic area were developed by our contractor, Brookhaven National Laboratory, and the RAls in the fire area were developed by our contractor, Sandia National Laboratories. All of the RAls were reviewed by the " Senior Review Board"(SRB). The SRB is comprised of RES and NRR staff and RES consultants (Sandia National Laboratories) with probabilistic risk assessment expertise in external events.
In order to best accomodate the review schedules for both the staff and contractors, we request that you provide a response within 60 days of receipt of this letter Sincerely,
%.} < -
%' k Douglas V. Pickett, Senior Project Manager Project Directorate 111-3 Division of Reactor Projects - lil/IV Office of Nuclear Reactor Regulation Docket No. 50-440
Enclosure:
As stated cc: See next page
L. Myers Perry Nuclear Power Plant, Units 1 and 2 Centerior Service Company cc:
Jay E. Silberg, Esq.
James R. Williams Shaw, Pittman, Potts & Trowbridge Chief of Staff 2300 N Street, NW.
Ohio Emergency Management Agency Washington, DC 20037 2855 West Dublin Granville Road Columbus, OH 43235-2206 Mary E. O'Reilly Centerior Energy Corporation Mayor, Village of Perry 300 Madison Avenue 4203 Harper Street Toledo, OH 43652 Perry, OH 44081 Resident inspector's Office Roy P. Lessy, Jr.
U.S. Nuclear Regulatory Commission Akin, Gump, Strauss, Hauer P.O. Box 331 and Feld, L.L.P.
Perry, OH 44081-0331 1333 New Hampshire Ave., NW.
Suite 400 Regional Administrator, Region 111 Washington, DC 20036 U.S. Nuclear Regulatory Commission 801 Warrenville Road Radiological Health Program Lisle, IL 60532-4531 Ohio Department of Health P.O. Box 118 Lake County Prosecutor Columbus, OH 43266-0118 Lake County Administration Bldg.
105 Main Street Onio Environmental Protection Painesville, OH 44077 Agency DERR-Compliance Unit Sue Hiatt ATTN: Mr. Zack A Clayton OCRE Interim Representative P.O. Box 1049 8275 Munson Columbus, OH 43266-0149 Mentor, OH 44060 Chairman Terry J. Lodge, Esq.
Perry Township Board of Trustees 618 N. Michigan Street, Suite 105 3750 Center Road, Box 65 Toledo, OH 43624 Perry, OH 44081 Ashtabula County Prosecutor State of Ohio 25 West Jefferson Street Public Utilities Commission Jefferson, OH 44047 East Broad S;reet Columbus, OH 43266-0573 Henry L. Hegrat Regulatory Affairs Manager William R. Kanda, Jr., Plant Manager Cleveland Electric illuminating Co.
Cleveland Electric illuminating Co.
Perry Nuclear Power Plant Perry Nuclear Power Plant P.O. Box 97, A210 P.O. Box 97, SB306 Perry, OH 44081 Perry, OH 44081
C 2
cc: (continued)
Donna Owens, Director Ohio Department of Commerce Division of Industrial Compliance Bureau of Operations & Maintenance 6606 Tussing Road P.O. Box 4009 Reynoldsburg, OH 43068-9009 Mayor, Village of North Perry North Perry Village Hall 4778 Lockwood Road North Perry Village, OH 44081 Attorney General Department of Attorney General 30 East Broad Street Columbus, OH 43216
)
I
Request for Additionalinformation Perry IPEEE A.
Seismic 1.
The IPEEE submittal states that since flat-bottom metal fluid storage tanks were not included in the success paths, their seismic capacities were not evaluated by the Seismic i
Review Team. These tanks were only reviewed for possible rupture during an earthquake.
To cope with seismic-induced flooding issues, the plant relies on dikes that surround these tanks to contain the fluids if the tanks do rupture. Since these dikes serve as the last barriers to contain fluids from flooding the plant safety equipment if a rupture occurs, it is important to quantify the seismic capacities of these dikes to resist a Review Leve!
Earthquake (RLE).
s.
Please describe the functions for which these dikes were originally designed. Was their originalpurpose to contain fluid from the tanks, or was their primary function to act as protective barriers for the tanks?
b.
Please also describe how the quantification of the selsmic capacities of these dikes to resist an RLE was carried out, and provide the capacities.
2.
Nonseismic failures are not discussed in the IPEEE submittal. According to EPRI NP-6041, non-seismic-caused component or system unavailability should be evaluated for single-train systems with recognized poor availability. An example provided in EPRI NP-6041 is the use of both Reactor Core isolation Cooling (RCIC) and High Pressure Coolant injection (HPCI) i for high pressure injection in a success path. However, in the Perry IPEEE, only High Pressure Core Spray (HPCS) is included in Success Path A for high pressure injection. This may not be consistent with the EPRI NP-6041 recommendations. According to the data presented in NUREG/CR-4550, the probabilities of nonseismic failures are very similar for a turbine-driven pump (used in RCIC and HPCI) and a diesel generator (used to provide electric power for HPCS).
The reliability of the HPCS system at Perry is further affected by the performance of the low-ruggedness relays used in the HPCS diesel generator control circuitry. According to the IPEEE submittal, chatter of some of these relays in a review level earthquake (RLE) may result in a lock out of HPCS diesel generator operation or a trip of the HPCS 4.16 kV bus diesel generator breaker, and manual reset is subsequently required for HPCS recovery.
a.
Please describe how the nonselsmic failure issue was treated in the Perry analysis, in keeping with the request in NUREG 1407, Section 3.2.6.8, which states that " success paths are chosen based on a screening criterion applied to nonselsmic failures and needed human actions. It is important that the failure modes and human actions are clearly identified and have low enough probabilities to not affect the seismic margins evaluation."
b.
Please describe in more detail the effect of nonseismic failure of the NPCS system on the selsmic margins evaluation.
i c.
Please discuss the combined effect of nonseismic failure and relay chatter on the availability of the HPCS system in an RLE. Please include in the discussion a more detailed description of the procedures (e.g.,
whether procedures are in place and what they are), operator actions (in and out of control room operadons), and operator availability for HPCS recovery sNor relay chatter. The dme available for recovery actions and the eWect of seismic conditions on operetor sedons need to be addressedin the discussion.
3.
Although many elements in the success paths require human actions, human actions are not discussed in the submittal. For example, containment venting is used in both success paths of the Perry IPEEE and is the sole source of containment overpressure protection for Success Path A. However, the human actions involved in containment venting and their failure probabilities are not discussed. Section 3.2.5.8 of NUREG-1407 requests that
" human actions be clearly identified and have low enough probabilities to not affect the seismic margins evaluation."
a.
Please address human acdon issues related to the success paths in accord with the statements in NUREG 1407 cNed above.
b.
Please describe the human actions involvedin containment venting.
Please include in the discussion the procedures used and detailed operator actions involved in the venting. The time available for operator actions and the eWect of selsmic conditions on operator acdons need to be addressedin the discussion.
B.
Fira 1.
In Table 4 3 of the submittal,18 fire areas are identified as not being screened out by the FIVE methodology Phase I and Phase 11 Step 2 screenings. However, fire area 1 ABE which contains RHR Train A elements is missing from Table 4-10 which lists the fire areas which did not initially screen along with their screening and final fire induced CDFs.
Please provide the results of the detailed analysis of fire area 1ABE and discuss its eWect on CDF, including, in particular, whether the analysis showed that the area screened out or remained above the 10* screening value.
2.
In general, credit was not taken for one-hour-rated raceway barriers, i.e., the ability of Thermo-Lag material to reduce temperatures or impede fire damage. However, in two fire compartments, DGid and CC2/4, circuits from each of the Appendix R Safe Shutdown divisions pass through these areas. Credit was taken for a one-hour-rated raceway barrier for one of the divisions in one of the compartments.
Please determine the conditional core damage probability (CCDP) If N is assumed that no Thermo-Lag is present In the subject compartments. Also, Identify any other areas where Thermo-Lag was credited and the eWect on CCDP of no creditis taken.
3.
NUREG-1407, Section 4.2 and Appendix C, and GL 88-20, Supplement 4, request that documentation be submitted with the IPEEE submittal with regard to the Fire Risk Scoping Study (FRSS) issues, including the basis and assumptions used to address these issues, and a discussion of the findings and conclusions. NUREG-1407 also requests that evaluation results and potentialimprovements be specifically highlighted. Control system interactions 2
involving a combination of fire-induced failures and high probability random equipment failures were identified in the FRSS as potential contributors to fire risk.
The issue of control systems interactions is associated primarily with the potential that a fire in the plant (e.g., the main control room [MCR]) might lead to potential control systems vulnerabilities. Given a fire in the plant, the likely sources of control systems interactions could happen between the control room, the remote shutdown panel, and shutdown systems.
Specific areas that have been identified as requiring attention in the resolution of this issue include:
(a)
Electricalindependence of the remote shutdown control systems: The primary concem of control systems interactions occurs at plants that do not provide independent remote shutdown control systems. The electricalindependence of the remote shutdown panel and the evaluation of the level of indication and control of remote shutdown control and monitoring circuits need to be assessed.
l (b)
Loss of control equipment or power before transfer: The potential for loss of control power for certain control circuits as a result of hot shorts and/or blown fuses before transferring control from the MCR to remote shutdown locations needs to be assessed.
(c)
Spurious actuation of components leading to component damage, loss-of-coolant accident (LOCA), or interfacing systems LOCA: The spurious actuation of one or more safety-related to safe-shutdown-related components as a result of fire-induced cable faults, hot shorts, or component failures leading to component damage, LOCA, or interfacing systems LOCA, prior to taking control from the remote shutdown panel, needs to be assessed. This assessment also needs to include the spurious starting and running of pumps as well as the spurious repositioning of valves.
(d)
Totalloss of system function: The potential for totalloss of system function as a result of fire-induced redundant component failures or electrical distribution system (power source) failure needs to be addressed.
Please describe how your pmcedures pmvide for transfer of control to the remote station (s). Proside en evaluation of whetherloss of controlpower due to hot shorts and/or blown fuses could occurprior to transferring control to the remote shutdown location andidentify the risk contribution of these types of failures (if these failures are screened, please pmvide the basis for the screening). Finally, pmvide en evaluation of whether spurious actuation of components as a result of fire induced cable faults, hot shorts, or component failures could lead to component damage, a LOCA, or an Interfacing systems LOCA prior to taking control from the remote shutdown panel (considering both spurious starting and running of pumps as well as the spurious repositioning of valves).
4.
Fire severity factors were used for analyses involving pump motor and compressor fires apparently based on NSAC-178L. The severity factors were apparently used in scenarios involving compartments which contain such components. Some of the compartments which were analyzed in detail have automatic fire suppression systems. As a result, the severity factors could have been used where automatic fire suppression was also credited. Since the 1
3
potential for a large fire is dependent upon fire suppression, such cases would result in double counting suppression efforts.
Please describe the fire scenarios in which automatic fire suppression was credited in cort l unction with the fire severity factors used in the Perry fire assessment. For each case explain why such credit does not constitute double counting forsuppression.
5.
The Perry Plant has an exemption for station transformers which are located less than 50 feet from the Turbine Building wall which has less than a three-hour fire rating. In addition, the area has no automatic fire suppression. This exemption was not discussed in the submittal nor analyzed in terms of a potential fire scenario. According to the submittal, the Turbine d
Building has a CCDP of 7.4x10. Since FIVE specifies a fire ignition frequency for the transformer of 1.5x102, it appears that the risk may be significant.
Please assess the risk (CCDP) of a transformer fire that spreads after breaching the barrier separating the transformer and the Turbine Building.
6.
The probability of manual non-suppression for a Control Room fire which would result in critical component damage was based on the estimated time available for suppression and a 4
model contained in Appendix J of the Fire PRA Implementation Guide. The unavailability value provided by the model could not be verified. Also, it was unclear how the value for the fire see: vo which would require evacuation of the Control Room due to smoke was determine ~ This scenario was also based on an estimated available suppression time. This approach is not consistent with the FIVE methodology.
Please describe the process and models used to obtain the non-suppression probabilities required for the analysis of Control Room fires. Compare the results to those which would have been obtained using the FIVE methodology.
7.
The heat loss factor is defined as the fraction of energy released by a fire that is transferred to the enclosure boundaries. This is a key parameter in the prediction of component damage, as it determines the amount of heat available to the hot gas layer. In Fire-induced Vulnerability Evaluation (FIVE), the heat loss factor is modeled as being inversely related to the amount of heat required to cause a given temperature rise. Thus, for example, a larger heat loss factor means that a larger amount of heat (due to a more severe fire, a longer buming time, or both)is needed to cause a given temperature rise. It can be seen that if the value assumed for the heat loss factor is unrealistically high, fire scenarios can be improperly screened ut. Figure R.1 provides a representative example of how hot gas layer temperature predictions can change assuming different heat loss factors. Note that: 1) the curves are computed for a 1000 kW fire in a 10m x Sm x 4m compartment with a forced ventilation rate of 1130 cfm; 2) the FIVE-recommended damage temperature for qualified cable is 700*F for qualified cable and 450'F for unqualified cable; and,3) the SFPE curve in the figure is generated from a correlation provided in the Society for Fire Protection Engineers Handbook [R1).
Based on evidence provided by a 1982 paper by Cooper et al. [R2), the EPRl Fire FRA implementation Guide recommends a heat loss factor of 0.94 for fires with durations greater than five minu es and 0.85 for " exposure fires away from a wall and quickly developing hot gas layers." However, as a general statement, this appears to be a misinterpretation of the i
a 4
results. ReferenceIR2], which documents the results of multi-compartment fire experiments, states that the higher heat loss factors are associated with the movement of the hot gas layer Time-Temperature Curves 900 800 SFE
-e-H.F = 0.70
-e-H.F = 0 85
$ 600-
--+- U = 0.94
~*
500 -
~~~
L
- ~ ~ ~ " ~ " '
300 - /
200 -
100 e W:ssex x x.x.x.x x:x,x.x x x *X* N R ? % '8 8 R j N *EgR?y?S 8
D
- Tim e (s)
Figure R.1 Sensitivity of the hot gas layer temperature predictions to the assumed heat loss factor from the buming compartment to adjacent, cooler compartments. Earlier in the experiments, where the hot gas layer is limited to the buming compartment, Reference (R2]
reports much lower heat loss factors (on the order of 0.51 to 0.74). These lower heat loss factors are more appropriate when analyzing a single compartment fire.
In summary, (a) hot gas layer predictions are very sensitive to the assumed value of the heat loss factor; and (b) large heat loss factors cannot be justified for single-room scenarios based on the information referenced in the EPRI Fire PRA Implementation Guide.
The Perry IPEEE fire study discusses heat loss factors only in conjunction with the detailed analysis of electrical cabinets in one fire compartment (1CC3a). No hot gas layer (HGL) temperature is estimated and HGL effects are apparently not considered important based on test data and referenced information that could not be verified. HGL effects were apparently also cMsidered in other detailed compartment analyses.
5
For each scenario where the hot gas layer temperature was calculated, i
please specify the heat loss factor value usedin the analysis, in light of the preceding discussion, please either: a) Justify the value used and discuss its effect on the identification of fire vulnerabilities, or L) repeat the analysis using a moreJustifiable value andpmvide the resulting change in scenario contribution to core damage frequency.
References for Fire RAls R1.
P.J. DiNenno, et al, eds., "SFPE Handbook of Fire Protection Engineering," 2nd Edition, National Fire Protection Association, p. 3-140,1995.
R2.
L. Y. Cooper, M. Harkleroad, J. Quintiere, W. Rinkinen, "An Experimental Study of Upper Hot Layer Stratification in Full-Scale Multiroom Fire Scenarios," ASME Journal of Heat Transfer,1Q4,741-749, November 1982.
i C. High winds, flood, and other external events There are no RAls in this area.
I 6
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