ML20133J179
| ML20133J179 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 10/11/1985 |
| From: | Brons J POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| References | |
| JPN-85-73, NUDOCS 8510180310 | |
| Download: ML20133J179 (9) | |
Text
123 Main street W%te Puns, New 'rc4k 10601 914 681.6240
- > NewYorkPower 0""3 ""'" -1 4# Authority
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Octalrr 11, 1985 JPN-85-73 Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Attention:
Mr. Domenic B. Vassallo, Chief Operating Reactors Branch No. 2 Division of Licensing
Subject:
James A. FitzPatrick Nuclear Power Plant Docket No. 50-333 Implementation of ATWS Rule Modifications
References:
1.
10 CFR 50.62, " Requirements for reduction of risk from anticipated transients without scram (ATWS) events for light-water-cooled nuclear power plants." (49FR26036) 2.
NYPA letter, J.
C.
Brons to D.
B. Vassallo, dated June 14, 1985 (JPN-85-47) regarding Integrated Implementation Schedule of SPDS and ATWS Rule Modifications.
Dear Sir:
In accordance with the requirements of the ATWS Rule (Reference No. 1), the Authority hereby submits the plan and implementation schedule associated with the required ATWS Rule modifications.
The Authority has selected the following conceptual design to meet ATWS requirements:
1.
Enriched boron for the standby liquid control system (SLCS).
2.
Multiple valve design for the alternate rod insertion (ARI) system.
More detailed information regarding this conceptual design is provided in Attachment No.
1.
No modifications are required for recirculation pump trip (RPT) since the existing RPT design was reviewed and approved by the NRC l
staff as part of the original licensing basis for FitzPatrick (See Attachment No. 1).
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The Authority's proposed schedule for the completion of ATWS I
modifications was previously submitted in Reference No.
2.
An updated implementation schedule is provided in Attachment No.
2.
The Authority's proposed completion date for ATWS Rule modifications is thirty days after the end of the third refueling outage after July 26, 1984 (i.e. Reload 8/ Cycle 9) or June 1, 1988, whichever is later.
This represents a one fuel cycle extension of the schedule contained in the ATWS Rule.
In addition to the justification provided in Reference No.
2, this extension is required to complete the engineering, design, and material Procurement for the ARI valves as shown in Attachment No.
2.
If you have any questions or would like to discuss this further, 3
please contact Mr. J. A. Gray, Jr. of my staff.
Very truly yours, hohn C. Brons Senior Vice President Nuclear Generation cc:
Office of the Resident Ins pec to r'#
U.S. Nuclear Regulatory Commission P.O. Box 136 Lycoming, N.Y.
13093 1
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AttachOent No. 1 to JPN-85 73 A.
Standby Liquid Control System (SLCl A.1 ATNS Rule i
Code of Federal Regulations 10 CFR 50 Sub. Section 50.62:
" Requirements for reduction of risk from anticipated transients without scram (ATWS) events for light-water-cooled nuclear power plants", states that each boiling v'ter reactor must have a
a standby liquid control system (SLCS) with a minimum flow capacity and boron content equivalent in control capacity to 86 l
gallons per minute of 13 weight percent sodium pentaborate solution.
The SLCS and its injection location must be designed to perform its function in a reliable manner.
In accordance with NRC Generic Letter 85-03 " Clarification of Equivalent Control Capacity for Standby Liquid Control Systems" issued to all boiling water reactor licenses and applicants on January 28, 1985, the equivalent SLC System flow required for FitzPatrick is 67.3 gpa of 13 weight % sodium pentaborate solution.
A.2 Standby Liquid Control System Current Desian The current FitzPatrick SLC System design consists of two pumps with rated flow of 50 gpa each.
The current SLC System is designed to operate one pump to inject the sodium pentaborate solution into the reactor.
Figure 1 shows a simplified flow diagram for the existing standby liquid control system.
The SLC System is initiated remote-manually from the control room.
The concentration of sodium pentaborate in the storage tank is maintained within about 9.2 wt.% to 17 wt.% depending on solution level in the tank in accordance with Technical Specification requirements.
The boron solution tank and pump suction piping are electrically heated to maintain a temperature between 750 to 850F to prevent precipitation of sodium pentaborate solution.
The existing injection point for the SLC System is a standpipe located in the lower plenum of the reactor pressure vessel.
The existing SLC' System does not meet the requirement of 67.3 gpa of 13 weight % of sodium pentaborate solution as required by the ATWS rule. -
A.3 Compliance with ATWS Rule The FitzPatrick SLC System will meet the 67.3 gpm of 13 weight %
of sodium pentaborate requirement by enriching the isotope B10 in the sodium pentaborate solution.
The enrichment needed to satisfy this requirement is 26.7 wt. percent of B10 isotope in the sodium pentaborate solution.
To achieve the i
required enrichment of boron, enriched boric acid (containing 55% B10) shall be added to natural borax to produce double enriched sodium pentaborate solution of 39.6 wt. percent l
B o.
The required final sodium pentaborate solution with I
26.7% enriched B10 isotope is achieved by mixing part of the existing natural sodium pentaborate (19.8% B o) with a l
proportional amount of double enriched sodium pentaborate solution (39.6% B10),
f i
l
F Approximately 35% by weight of double enriched sodium pentaborate is required to produce 26.7% enriched B10 isotope in the final solution.
The current design of the SLC System will be able to handle the increased enrichment of the sodium pentaborate solution because the enriched boron solution is chemically similar to the current sodium pentaborate solution.
Using an enriched solution will not change any of the key SLC System process parameters (flow rates, discharge pressure, required NPSH etc.).
Enriched boron solution will be used at FitzPatrick to meet the ATWS requirement for the SLC System.
For the FitzPatrick plant, the designated injection point of the SLC system boron solution is a standpipe located in the lower plenum of the RPV.
Based on work performed by GE for the BM2OG EPG Committee, including scale model testing, the NRC has accepted (in the Safety Evaluation Report on the BWR EPGs) the injection of the SLC System solution into the standpipe as an ATWS mitigating procedure.
The existing injection point for the SLC system for FitzPatrick plant will be retained for use as part of the ATWS mitigating system.
A.4 Schedule This modification will be installed during the 1988 refueling outage.
Refer to Attachment No. 2 for the detailed schedule for ATWS Rule modifications.
B.
Recirculation Pump Trip (RPT)
B.1 ATWS Rule 10 CPR 50.62 (c)(5) states that each boiling water reactor must have equipment to trip the reactor coolant recirculating pumps automatically under conditions indicative of an ATWS.
This equipment must be designed to perform its function in a reliable manner.
B.2 RPT Current Desian In the FitzPatrick Plant, each recirculation system M-G is tripped independently of the other.
Each M-G Set trip is initiated by two level sensors (sensing vessel low water level) and two pressure sensors (sensing high vessel pressure).
Each level and pressure sensor is connected to an analog trip module provides a trip signal output when a predetermined low that vessel level or high vessel pressure is achieved, respectively.
Level Sensors Loops 2-3-72A or 2-3-72C or Pressure Sensor Loops 2-3-102A or 2-3-102C will trip Recirculation System M-G Set A l
whereas Level Sensor Loops 2-3-72B or 2-3-72D or Pressure Sensor Loops 2-3-102B or 2-3-102D will trip Recirculation System M-G Set B.
(See Figure 2).
(
The logic associated with these sensors is arranged in a "one-out-of-two" for each of the two process variables to energize the trip circuit for each M-G Set Drive Motor.
The trip signal for each set of logic is applied to the trip coil of the respective feeder breaker.
B.3 Compliance with ATWS Rule The present FitzPatrick Plant RPT design has been reviewed by NYPA for the ATWS requirements, The installed trip logic for the RPT system meets the specific guidance on RPT provided in the Statement of Considerations associated with the ATWS Rule.
The existing RPT design was reviewed and approved by the NRC
,ataff as part of the original licensing basis for FitzPatrick.
Therefore, NYPA does not intend to modify this system.
B.4 Schedule No modifications are required since the existing RPT logic meets the ATWS requirements.
C.
Alternate Rod Iniection (ARI) System C.1 ATWS Rule 10 CFR 50.62 (c)(3) states that each boiling water reactor must have an alternate rod injection (ARI) system that is diverse (from the reactor trip system) from sensor output to the final actuation device.
The ARI system must have redundant scram air header exhaust valves.
The ARI must be designed to perform its function in a reliable manner and be independent (from the existing reactor trip system) from sensor output to the final actuation device.
C.2 ARI System Current Design None C.3 Compliance with ATWS Rule NYPA intends to install a multiple valve Alternate Rod Injection system that will have diverse electrical logic to the RPS scram.
The specific number of values and exact valve configuration has not yet been determined.
The logic for activating the ARI valves will be installed in a cabinet separate from the RPS cabinets in the relay room.
The logic system will be diverse from the existing RPS.
It will be initiated from the existing sensors used to provide a trip signal for the Recirculation Pumps.
Relay output contacts located in the ECCS cabinets will be used for this function.
The logic will be arranged in a "two-out-of-two" logic to prevent an inadvertent trip of the single process sensor loop.
The ARI scram valves will be actuated by energizing them, where-as the scram. valves are actuated by de-energization.
The ARI valves will be sealed in for a specific time period following a process trip to ensure the depressurization of the scram pilot air headers.
The logic (up to the solenoid coil on the ARI valve) will be testable during plant operation.
C.4 Schedule The ARI valves are long lead items which have a delivery time of 50 weeks.
Taking into consideration the time for engineering, design and material procurement, this modification will be installed during the 1988 refueling outage. ' Refer to Attachment No. 2 for the detailed schedule for ATWS-Rule modifications.
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Figure 1
Existing Standby Liquid Control (SLC) System
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e LOW LEVE L Hi PRESS LOW LEVEL HiPRESS 2472A 24102A 2 #728 2-3-1028 I
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I LOW LEVE L HI PR ESS LOW LEVE L HI PRESS 2472C 2-3102C 23-720 2-3-102D REClRC LOGIC 1/2 RECIRC M-G M-G SET A.
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i Figure 2 FitzPatrick Current RPT Design
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Attachment No. 2 to JPN-85 73 Schedule for ATWS Rule Modifications - James A.
FitzPatrick Nuclear Power Plant Activity (Start Date)
Completion Date 1.
Prepare and Issue Capital Expenditure 5/15/85 Authorization Request (CEAR)
(April 15, 1985) 2.
Prepare and Issue Request for 5/17/85 Proposal (RFP) for Plant Unique Analysis to Identify Design Alternatives (April 15, 1985) 3.
Completion of Plant Unique Analysis (June 2, 1985) 9/27/85 4.
Evaluation of Alternatives and Prepare and 12/1/85 Issue Conceptual Design Package of Selected Design (June 15, 1985) 5.
Prepare and Issue RFP for Detailed 2/1/86 Engineering and Design (December 1, 1985) 6.
Evaluate Bids for Detailed Engineering 5/15/86 and Design, Award Contract (March 15, 1986) 7.
Detailed Engineering including 8/15/87 Preparation of Installation Package and Preparation of pre-operational Test Procedures (May 15, 1986) 8.
Procurement and Delivery of Long-Lead 10/15/87 Time Items Alternate Rod Insertion Valves)
(October 1, 1986) 9.
Installation of Non-outage Related Prior to Outage Work as Operation Allows (December 31, 1987)
- 10. Installation of Work which 30 Days After End Requires Plant Outage of Reload 8/ Cycle 9 Refueling Outage or 6/1/88, whichever is later.
Note:
With the exception of the final completion date, the details of the above schedule may change.
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