3F1097-08, Rev 1 to License Amend Request 220,supersedes 970626 Application,Removing Portion of License Condition 2.C.(5) Which Requires Installation & Testing of Flow Indicators in ECCS for Boron Dilution.Description of Changes Encl
| ML20198N426 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 10/31/1997 |
| From: | Cowan J FLORIDA POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 3F1097-08, 3F1097-8, TAC-M99128, NUDOCS 9711040225 | |
| Download: ML20198N426 (11) | |
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October 31, 1997 i
3F1097-08 U. S. Nuclear Regulatory Conmission Attn: Document Control Desk Washington, DC 20555-0001
Subject:
License Amendment Request #220, Revision 1 Revision of Operating License Condition 2.C.(5)
References:
- 1. FPC to NRC letter, 3F0697-08, dated June 26, 1997, " License Condition 2.C,(5) Requiring Installation ana Testing of Flow Indicators"
- 3. FPC to NRC letter, 3F1097-32, dated October 31, 1997, " License Amendment Request #223, Revision 0, Post 10CA Boron Precipitation Prevention"
- 5. K3C to. FPC- letter, 3N1185-06, dated November 12, 1985, Post Accident Sampling System"
Dear Sir:
Florida Power Corporation (FPC) nereby submits a revision to the request for an amendment to its Facility Operating License No. DPR-72 for Crystal River linit 3 (CR-3). This License Amendment Request (LAR) supersedes, in its entirety, the i previously submitted request in Reference 1. This LAR (previously not numbered) has been assigned LAR number 220 for FPC tracking purposes. g gtDt 9711040225 971031
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CRYJTAL RIVER ENERoY COMPLEX: _157so W. Power une street e Crynal River, Florida 34428-6700 e (352) 796 6488
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l U. S. Nuclear Regulatory Commission 3F1097-08 Page 2 of 3 This LAR proposes to remove that portion of Operating License Condition 2.C.(5) which requires installation and testing of flow indicators in the Emergency Core Cooling System (ECCS) for boron dilution. These indicators were originally used to support post loss-of-coolant-accident (LOCA) boron precipitation control. The
- need for this instrumentation has been replaced in the current post-LOCA boron precP,,itation mitigation plan by valve position indication in the mitigation paths and reliance on the monitoring of the boron concentration in the Reactor Building (RB) ECCS sump as an indication of boron concentration in the reactor
-vessel. This concentration will be measured by the Post Accident Sampling System (PASS) boron sensor, CA-56-CE.
CR-3 has two active nethods and one passive method that will be available for post-LOCA boron precipitation mitigation. The active methods are Decay Heat (011)
System drop line or hot leg injection through the Auxiliary Pressurizer Spray
-(APS) line. The passive method is Reactor Vessel Vent Valve (RVVV) flow within the reactor vessel.
Attachment A describes the proposed changes along with the 10 CFR 50.92(c) evaluation and conclusion that the proposed changes do not involve a significant hazard.
There are no commitments in this letter.
FPC requests that this license amendment be approved by December 1,1997 with a 30 day implementation period. This schedule will support the restart of CR-3 in mid-December 1997.
If you have any questions regarding this submittal, please contact Mr. David r'nsemiller, Manager, Nuclear Licensing at (352) 563-4566.
Sincerely, M N John Paul Cowan Vice President Nuclear Pr' duction JPC/jwt Attachment cc: Regional Administrator, Region 11 NRR Project Manager Senior Resident inspector
,s . .
U. S. Nuclear Regulatory Commission 3F1097 Page 3 of 3 STATE OF FLORIDA COUNTY OF CITRUS John Paul Cowan states that he is the Vice President Nuclear Production for Florida Power Corporation; that he is authorized on the part of said company to sign and file with the Nuclear Regulatory Commission the information attached--
hereto; and that all such statements made and matters set forth therein are true and correct to the best of his knowledge, information, and belief, k&& J John Paul Cowan Vice President Nuclear Production Sworn to and subscribed before me this d day of Oede he r , 1997, by John Paul Cowan.
uC '3j'gnatu[e of Notary Public S u[d[s ,en My Comm. Exp. 0ct. 25.1900 Comm. N. CC 505458 Mate of Morda bN 4. kn is & 'h//
(Print, type, or stamp Commissioned-Name of Notary Public)
Personally Produced Known )( -0R- Identification 1
U. S. Nuclear Regulatory Commission Attachment A 3F1097-08 Page 1 of 8 LICENSE AMENDNENT REQUEST (LAR) #220, REVISION 1 Revision of Operating License condition 2.C.(5)
LICENSEE DOCUMENT INVOLVED: Crystal River Unit 3 (CR-3) Operating License DPR-72 PORTIONS: Operating License Condition 2.C.(5)
SUMMARY
OF CHANGES:
A change is being proposed to a portion of Operating License Condition 2.C.(5) to remove the requirement for installation and testing of flow indicators in the Emergency Core Cooling System (ECCS) to provide indication of 40 gallons per minute flow for baron dilution. Consistent with the mitigation plan described in Reference 3, this instrumentation is no longer necessary. For accidents involving breaks in the Reactor Coolant System (RCS), current emergency plant procedures already require operators to immediately begin cooldown of the RCS to avoid a loss of subcooling margin. These emergency operating procedures and coordination of the Technical Support Center (TSC) activities will assess the cppropriate actions to be taken for boron precipitation mitigation and these actions do not rely on either of these flow indicators.
The current licensing basis post-LOCA boron precipitation citigation methods are (1) Reactor Vessel Vent Valves (RVVV), (2) Decay Heat (OH) System drop line (dump-to-sump) flow path, and (3) hot leg injection via the Auxiliary Pressurizer Spray (APS)flowpath. Hetnods 1 through 3 have been accepted by the NP.C as part of the licensing and design bases for CR-3. Flow through the DH System drop line or APS will be initiated by opening the associated valves in the flow path. For the APS method, the associated valves will be fully opened. For the dump-to sump method, the associated valves will be fully opened except for DHV-42 or DHV-43 (rump suction valves) which will be partially opened. Flow through these lines will be demonstrated by the position indicators of the valves in the associated flow paths. These valves and position indicators are safety-related except for one valve in the APS flow path (RCV-53). These valves are also powered via Class IE, Emergency Diesel Generator power sources. RCV-53 is safety-related for pressure boundary, but the operator, limit switch, and position inoicator are not safety-related. The non-safety-related components are Environmentally Qualified (EQ) and subject to the requirements of the Maintenance Rule.
The degree to which each of these methods will lead to successful mitigation of boron precipitation is based upon Reactor Building (RB) ECCS Sump boron concentration at measured by the Post Accident Sampling System (PASS) boron sensor, CA-56-CE. None of these methods rely on either DH-45-FI or DH-46-FI as a basis .for mitigative actions. Therefore, this license amendment should be approved to remove that portion of Operating License Condition 2.0.(5).
j U. S. Nuclear Regulatory Commission Attachment A 3F1097-08 Page 2 of 8 CHANGE TO OPERATING 1.! CENSE CONDITION 2.C.(5)
Description of Changa The proposed change revises Operating License condition 2.C.(5) by removing the strikeout wording shown below:
2.C.(5) Within six months of the date of issuance of this license, Florida Power Corporation shall complete modifications to the level indication of the borated water storage tank, 4nst+Het4en-and-test 4ng cf flow-4edicator; in the mergency ccre eccling- cysten-te-pevide indit-at4en-of 10 gallen: per minute ficw for borca dilut4ent and installation of dual setpoint pilot-cperated relief valve on the pressurizer.
Egason for Recuest Flow indicators DH-45-FI (OH System drop line) and DH-46-FI (APS line) were originally installed in 1977 to satisfy Operating License Condition 2.C.(5) to provide indication of 40 gallons per minute (gpm) flow for boron dilution. These indirators provided operator information necessary to aid in post-LOCA decision making associated with the prevention of boron precipitation. These flow indicators are no longer required by the CR-3 boron precipitation mitigation plan. Furthermore, the instruments do not provide any information which could aid the operator in assessing the effectiveness of any boron mitigation method.
Elimination of the requirement for flow indication from Operating License Condition 2.C.(5) is necessary to abandon or physically remove the indicators from CR-3.
Justification for Reouest In B&W Topical Report 10103, "ECCS Analysis of B&W's 177FA Lowered Loop NSS," CR-3 relied on a natural circulation condition to exist within the reactor vessel through the Reactor Vessel Vent Valves (RVVV). This natural circulation overflow through the RVVV continues in excess of 40 days. This natural circulation flow diminishes to a point where it can no longer e. ectively prevent boron concentration. Before that point is reached, CR-3 operators would establish either recirculation via the DH System drop line to the Reactor Building (RB)
ECCS Sump or begin hot leg injection via the Auxiliary Pressurizer Spray (APS) line. The hot leg nozzle gaps were evaluated, but credit for them was never taken. The degree to which these success paths were effective was judged to be the ability to verify that a flow rate of 40 gpm was occurring in the DH System drop line and APS flow path. Therefore, this established License Condition 2.C.(5) for flow indication.
In Reference 3, FPC discusses the licensing basis methodologies used at CR-3 to mitigate baron precipitation that could occur under certain post-accident conditions. These methodologies rely on either (1) Reactor Vessel Vent Valves,
'(2) Decay Heat System drop line, or (3) hot leg injection via the Auxiliary
1 U. S. Nuclear Regulatory Commission Attachment A 3F1097-08 Page 3 of 8 Pressurizer Spray (APS) path. These methods rely upon valve position indication to establish the boron mitigation flow path rather than the flow instrumentation.
The effectiveness of any of these methods is assessed with the Post Accident Sampling System (PASS) boron concentration monitoring of the RB ECCS Sump. These options do not utilize DH-45-Fi or DH-46-FI and therefore, these indicators are no longer required. Since these indicators are no longer required to support post-LOCA boron precipitation control, removing their reference in License Condition 2.C.(5) is appropriate.
The post-LOCA boron precipitation plan submitted by Reference 3 consists of the -
following methods:
Post-LOCA Boron Precipitation Boron Dilution Methods Description Reactor Vessel Vent Valves Allows boron dilution within the reactor (passive) vessel.
Decay ffdat (DH) System drop Allows gravity feed of reactor coolant from line to the RB ECCS Sump the ho6 leg through the DH System drop line (active) to the RB ECCS sump.
Hot Leg injection with Provides dilute injection flow from the APS Auxiliary Pressurizer Spray into the reactor vessel via the hot 'eg.
(APS) (active) Several days after the accident, the flow rr.e would exceed the boil off rate and the excess flow would provide boron dilution.
The DH System drop line to the RB ECCS sump method consists of opening three valves (DHV-3, -4, -41) in the DH System drop line to establish a gravity feed path from the hot leg to the RB ECCS sump. After the DH System drop line valves are open, the operator is procedurally instructed to open either DHV-42 or DHV-43
. (RB ECCS sump isolation valves located outside the RB) to allow blowdown to the RB ECCS sump. When the operator manually opens these valves, he uses the main control board valve indicating lights to indicate when the valve begins to open.
Reference 2 verified that these valm, main control room panels where the indicators are located, switches, and '. .ght sockets are safety-related. FPC has demonstrated by analysis that the minimum flow rate through the line would be in excess o' che required flow. Approximately 10 gpm through the DH System drop line is required to provide adequate boron dilution flow. Therefore, if the DH System drop line is opened per the plant procedures, the minimum required flow rate is assured. The valves in this flow path all have safety-related valve position. indicators and Class lE power available. Additionally, the adequacy of the . boron dilution method will be monitored by evaluating RB ECCS sump boron concentration.
The hot leg injection with the APS method consists of supplying dilute injection flow to the hot leg through the pressurizer. This method would only be effective several uays following the accident when the APS flow rate would exceed the boil off rate. At that time, the excess flow via APS would provide boron dilution.
l t . .
U. S. Nuclear Regulatory Commission Attachment A 3fl097-08 Page 4 of 8 Like the DH System drop line method, flow is ensured by opening the valves in the flow path and monitoring the RB ECCS sump boror, concentration for effectiveness. .
In both active methods, the available flow rate will be achieved by the opening of the affected line. Flow through these lines will be monitored by the position indications of the valves in the associated flow paths. Decision making for post-LC-CA baron precipitation control will not be based on flow rates through the '
lines, -but on establishing the flow path (opening valves) and measuring the effectiveness of the method by RB ECCS sump boron concentration. Heither method requires the use of the flow indicators sinc.u actions will continue to be taken, regardless of flow indication, as long as the RB ECCS sump concentration is unacceptable.
The degree to which the boron dilution methods are leading to successful mitigation of boron precipitation will be based upon Reactor Building (RB) ECCS Sump boron concentration as measured by the Post Accident Sampling System (PASS) boron sensor, CA-56-CE. PASS was developed as a result of the TH1-2 accident to provide for prompt sampling and analysis of reactor coolant its function as described in NUREG-0578, "TM1-2 Lessons Learned Task Force Status Report and Short-Term Recommendations," (page A-34) and NUREG-0737, " Clarification of TMI Action Plan Requirements," Item II.D.3, is to provide informction important to the efforts to assess and control the course of an accident. The CR-3 PASS was designed and built to meet the requirements specified in NUREG-0737. The NRC reviewed and approved the CR-3 PASS in References 4 and 5, therefore it is considered to be available for the mitigation strategies.
The valves and associated valve characteristics for the flow path of each post-LOCA boron dilution method R provided in Tcble 1. The power supplies for these valves are Class lE and can ce powered from the Emergency Diesel Generators.
The.te valves, with the exception of RCV-53, are safety-related with controls and valve position indication located in the main control room. RCV-53 in the APS flow path is safety-related for pressure boundary and main control board indication. Its motor-operator and limit switch are non-safety-related, but they are environmentally qualified and included under the Maintenance Rule Program.
A recently identified failure of Motor Control Center (MCC)-3AB could prevent the use of either the dump-to-sump flow path or the APS flow path. However, this failure does not affect the single failure criteria for the boron 5.recipitation methods since the dump-to-sump flow path and the APS flow path are not the sole credited methods for any break size / location discussed in Reference 3.
An additional consideration for the use of the hot leg injection with APS method concerns run-out conditions for the Low Pressure Injection (LPI) pumps. The LPI System flow rate is monitored by flow indicators on the LPI discharge to the High Pressure Injection System pumps and on the LPI discharge to the Core Flood Tank
- .ozzles. These two flow indicators are used to ensure pump run-out conditions are not reached. However, the APS line branches off the LPI discharge line prior to these two flow indicators. Since the need for this method does not occur until several days after the accident began, the Technical Support Center procedures directing establishment of this method will address the need for controlling LPI flow in thir situation.
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U. S. Nuclear Regulatory Commission Attachment A 3F1097-08 Page 5 of 8 The flow indicators required by Operating License Condition 2.C.(5) were originally installed to provide indication of boron dilution flow in the DH System drop line and APS line. DH-45-Fi and DH-46-Fi provided the osrator with information necessary for making decisions regarding the prevention of boron precipitation following design basis LOCAs. However, with the incorporation of different boron dilution mitigation strategies described in Reference 3, there is no need to quantify the amount of flow and therefore, the need for this instrumentation his been eliminated.
NO SIGNIFICANT HAZARDS CONSIDERATION:
An evaluation of the proposed license mendment has been performed in accordance with 10 CFR 50.91(a)(1) regarding significant hazards considerations, using the standards in 10 CFR 50,92(c).
- 1. Does not involve a significant increase in the probability or consequences of an accident previously evaluated.
This License Amendment Request removes the Operating License Condition that requires flow indication in the ECCS system for boron dilution. Under cartain post-accident scenarios, boron dilution acticns could be required following design basis LOCAs to ensure that boron precipitation does not occur within the reactor core. Sine.e these methods involve post-accident conditions, they are not the initiators for any design basis accident.
Removal of this requirement from the license condition does not involve a change in the improved Technical Specifications. Since these instruments are no longer used for boron precipitation mitigation during a LOCA, abandonment or removal of flow indicators DH-45-Fi and DH 46-FI does not increase the probability of an accident because no previously evaluated accidents at CR-3 are initiated by DH-45-FI or DH-46-Fl. Since DH-45-Fi and DH-46-Fi are attached to the outside of the Gri System drop line and the Auxiliary Pressurizer Spray line, respectively, their removal will not change the -
design, material, or construction standards applicable to the DH System piping. Therefore, the removal of the requirement for this instrumentation does not increase the probability of an accident previously evaluated.
Removal of the requirement for the flow indicators does not change the effectiveness of the post-LOCA boron dilution capabilities at CR-3. Removal of DH 45-FI and DH-46-FI will not alter any assumptions made in evaluating the radiological consequences of any accident described in the FSAR nor will it affect any fission product barrier since the ECCS and containment systems will still perform to meet design requirements. Based on these conclusions, previously calculated 10 CFR Part 100 consequences have not changed as a result of this action.
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U. S. Nuclear Regulatcry Commission Attachment A 3F1097-08 Page 6 of 8
- 2. Does not create the possibility of 'a new or different kind of accident from any accident previously evaluated.
The flow indicators are external to the DH System piping. They do not penetrate any piping so their removal cannot create the possibility of a new or different kind of accident. The function of the valve position indicator on each valve in the active mitigation paths provide the operators with indication of valve open/close status. The indicators do not actuate any systems, structures, or components that are credited with accident mitigation. They can not initiate a new or different kind of accident. The boron precipitation mitigation methods are all implemented after the accident has occurred. None of the mitigative methods are required before an accident. The DH System drop line and the Auxiliary Pressurizer Spray are used during the course of CR-3's normal operation. Those methods of operation have been evaluated in the development of previously approved licensing basis and found acceptable. Using these previously approved methods in these post-accident conditions, eliminaticn of the subject license .
condition language, and the utilization of the boron dilution mitigation methods does not create the possibility of a new or different kind of design basis accident.
3.'Does not involve a significant reduction in the margin of safety.
Mitigation of potential boron precipitation will be accomplished by a combination of active and passive methods already included in the CR-3 licensing basis. The margin of safety for being able to abate boron precipitation is improved through the utilization of mcitiple available options. Therefore, there is no reduction in the margin of safety as a result of not utilizing DH-45-FI and DH-46-Fl.
ENVIRONMENTAL IMFACT EVALUATION:
10 CFR 51.22(c)(9) provides criteria for and identification of licensing and regulatory actions eligible for categorical exclusion from performing an environmental assessment. A proposed amendment to an operating license for a facility requires no environmental assessment if operation of the facility in accordance with the proposed amendment would not (1) involve a significant hazards consideration, (2) result in a significant change in the types or significant increase in the amounts of any effluents that may be released off site, or (3) result in a significant increase in individual or cumulative occupational radiation exposure. FPC has reviewed this license amendment and believes it meets the eligibility criteria for categorical exclusion set forth in 10 CFR_51.22(c)(9). Pursuant to 10 CFR 51.22(c), no environmental impact statement or environmental assessment needs to be prepared in connection with the issuance of the proposed license amendment.
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i U. S. Nuclear Regulatory Commission Attachment'A 3F1097-08 Page 7 of 8
Conclusions:
- 1. The proposed license amendment does not involve a significant hazard as described previously in the evaluation. .
- 2. The proposed changes to the Operating . License Condition does not introduce any new equipment, does not require any exitting equipment or systems to perform a different type of function than they are presently designed to perform, nor does it require any new operator actions. _The change tc the Operating License condition will not result in new additions to the plant equipment nor a change in the operation of the plant prior to the postulated design basis LOCA. The proposed license amendment does not result in a significant change in the types or a significant increase in the amounts of any effluents that may be released off site and does not involve irreversible environmental consequences beyond those already associated with the Final Environmental Statement.
- 3. The proposed license amendment does not change the operation of the plant nor the consequences of a design oasis accident. Deletion of the flow insttument license condition will reduce maintenance on the instruments and, therefore, does not result in a significant increase to the
_ individual or cumulative occupational radiation exposure.
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Attachment A-U. S. Nuclear Regulatory Comission Page 8 of 8
_3F1097-08 Table 1. Post-LOCA Boron Dilution Flow Paths I Safety Classification -l
}
Valve is - safety: N - Nonsafety; Control / EQ &mmtah
' Post-LOCA Boron Class IE Valve ID Indication in Power Supply U"*"
Dilution Method the Main Control Rom Valve Operator DHV-3 Yes Yes S S/EQ DHV-4 Yes Yes S S/EQ DHV-39 Yes Yes S S/EQ Drop Line to RB ECCS DHV-40 Yes Yes S S/EQ Sump DHV-41 Yes Yes S S/EQ DHV-42 Yes Yes S S/EQ DHV-43 Yes Yes S S/EQ Yes Yes S S/EQ Hot Leg Injection DHV-91 with Auxiliary RCV-53 Yes Yes S N/EQ Pressurizer Spray d
-~-
1 - _ - _