ML20202D800
| ML20202D800 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 02/06/1998 |
| From: | Curry D External (Affiliation Not Assigned) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUM2-PPNR-1089, NUDOCS 9802180006 | |
| Download: ML20202D800 (6) | |
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PARCONO Daniel L Curry, vo hae wrowcw reven Parsons tmtgy & Chemitais Group inc 2075 Morgantown A%d
- F%ad.ng. Pennsylvania 19607 * (010) 855 P300
- f or (010) 855 2002 February 6,1998 Docket No. 50 336 Parsons NUht2 PPNR 1089.L U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 hiillstone Nuclear Power Station Unit No. 2 Ltdepcadent Corrective Action Veri & cation Progmm. (ICAVP)
Gentlemen:
On July 25, August 4, August 29 and September 29,1997, Parsons Power submitted for NRC review and approval, the Critical Design Characteristics (CDCs) for the Tier 2 Accident hiitigation Systems Review (AhtSR). By letters dated October 15,1997 and January 20,1998, the NRC provided the results of the review of the Parsons CDC Submittals.
nc NRC identified additional system parameters that are important to the safety analyses described in Chapter 14 of the FSAR. The NRC requested Parsons to incorporate the additional system parameters into the ICAVP Tier 2 review. The NRC r ther requested that Parsons provide an update to the NRC that ur identified where cach of the additiord paameters were incorporated.
Based on subsequent discussions between Parsons and the NRC staff, the following action has been initiated. Parsons will incorporate the additional system parameters as noted in Attachment 1. Parameters will be validated as CDCs or as initial Conditions (ICs). CDC's apply to actions taken to mitigate the event (e.g., initiate liigh Pressure Safety injection). ICs apply to conditions that represent the plant configuration for initiation of the evem (c g., reactor power = 100%) or which are used to establish bounding results (e g., pressurizer spray disabled).
%c validation method will be consistent with the accident analysis design inputs. Specific clarifications are included in the " Parsons Action" column of Attachment 1. The Tier 2 Final Report will contain a complete listing of the validated parameters.
Please call me at (610) 855 2366 if you have any questions.
Sincerely, W
clau.
Daniel L. Curry Parsons ICAVP Project Director
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DLC:cyb Attachment ec:
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- 1. Fougere NNECo H I lill lilI H
- 11. Eichenholz USNRC Rep. Terry Concannon - NEAC R. Laudenat - NNECo Project Files
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, ATTACllMENT 1: DISPOSITION OF NRC COMMENTS
= ADDITIONAL SYSTEM PARAMETERS IMPORTANT TO SAFETY ANALYSIS FOR MILLSTONE UNIT 2 (NRC Letter of October 15,1997) 6 NRC Comment Parsons Action
- 1. Sy11cmhtamriert.ApplicabiclaAllAccident Analysgj
- a. Control rod worth as a function of control rod
- a. Will validate that physics test prograrn insertion.
includes appropriate measurement and acceptance criteria for rod worth values used in accident analyses.
- b. Trip setpoints and delay times.
- 1) as used in the accident analyses.
(Reference to Table 14.0.2-1 appears to be a typographical error).
- c. Reactor Coolant Pump (RCP) coastdown flow rate
- c. Validate four pump trip coastdown flow rate as CDC
- d. Componen" capacities and setpoints. (FSAR Table
- d. Validate as CDC/IC 14.0.8 1)
- 2. Sicamly11tRLPipingfAihlIt
- a. Minimum final reactor coolant loop f5w to
- a. Validate as IC calculate Departure from Nucleate Boiling Ratios
, (DNBRs),
- b. Validate as CDC setpoints trip signal delay times and control rod insertion delay times.
- c. liigh Pressure Safety injection (IIPSI) actuation:
- c. Validate as CDC/IC Setpoints, delay time, safety injection (SI) flow with and without a loss of offsite power with a combination of the worst single failure, and Si boron concentrations.
- d. Main Steam System: Isolation valve actuation
- d. Validate as CDC setpolat, delay time, and isolation valve closure time.
- c. Main Feedwater System: Flow rate, temperature,
- c. Validate as CDC/IC termination of feedwater flow, delay time, and isolation valve closure time.
- f. Auxillt ry Feedwater System (AFWS): Actuation
- f. Validate as CDC/IC. Note: AFWS signal and time of AFWS, flow rate, temperature, isolation is manual.
isolation actuation setpoints, delay time, and isolation valve closure time.
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- a. Flow area for two PORVs.
- b. Thermal Margin / Low Pressure (TM/LP) trip: Trip
- b. Trip delay time is treated as a pressure delay time.
bias and does not lend itself to validation. Validate trip breaker, CEA i
holding coil and rod insertion times.
- 4. SitanLGentialot Tube Rupture (SGTR)
- a. Emergency Operating Procedure (EOP) for the
- a. Validate as CDC operators to terminate the radiological releases from the affected steam generator (SG) at the end of 60 minutes following the SGTR event.
- b. Setpoints for bypass and atmospheric valves to open
- b. Validate setpoints as CDC/IC. RCPs and close, criteria and EOP for the operator to trip are assumed to nm throughout the the reactor coolant pumps (RCPs). (FSAR Table transient.
14.6.3 4)
- c. Maximum tube les' age in the unaffected SG
- c. Validate as 1C allowed by technical specifications (TS).
5 Lo1EofCQDlanLAccidents1LOCAs)
- a. Tables 14.6.5.1.4 and 14.6.5.212 14.6.5.1.4 and 14.6 5.2.12) present LOCA results. Results presented in the FSAR Tables will be compared with results presented in the supporting analysis documents,
- b. Develop system specific critical characteristics for
- b. Submitted to NRC on September 29, the flydrogen Control System and the Enclosure 1997. NRC comments issued January Building Filtration System that are critical systems 20,1998. Parsons disposition included for LOCA mitigation.
in this attachment.
- 6. Rodlank Withdrawal at. Low Power
- a. Variable high power trip setpoints,
- a. Validate as CDC
- b. Flow rate through the letdown valve.
- b. Validate as IC
- c. Actuation setpoint for the pressurizer spray.
- c. Validate as IC
- 7. Rod _ Ranks.ithdrawal at Power
- a. Closure time for the turbine valve.
- a. Validate as CDC
- b. Actuation setpoint for the steam line safety valve.
- b. Validate as CDC
- 8. Chemical and Volume Control System (CVCS) Induced Deboratio.D -
- a. Charging pump flow rates for modes 1 through 6.
- a. Validate as CDC/!C
- b. Initial shutdown margin boron concentrations.
- b. Validate as IC
- 9. Rod Election Accident
- a. Letdown flow rate.
- a. Validate as IC
- b. Flow rate for the makeup pump.
- b. Validate as IC
- c. Actuation setpoints for the pressurizer and steam
- c. Validate as CDC line safety valves.
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ADDITIONAL SYSTEM PARAMETERS IMPORTANT TO SAFETY ANALYSIS FOR MILLSTONE UNIT 2 (NRC Letter of January 20,1998)
NRC Comment Parsons Action A. SECTION 2.2, " FUEL IIANDLING ACCIDENT IN Tile SPENT FUEL POOL'
- l. Additional Mitigation Systems
- a. Reactor Building Closed Cooling Water
mitigation function for this event.
SFPCI RO, but not included in Section 2.2.3, System Interface).
- b. Main Exhaust system for initial ventilation
- b. Validate as IC for 366 days and $.ysar
' (shown on M2 T28BD MEl, but not included in cases.
Section 2.2.3, System interface).
- 2. Additional comments on Section 2.2.5.2 of the Critical Design Characteristics (CDC)
- a. The Functional / System CDC: " radiation
- a. CDC Deleted monitoring system alarm setpoint include Fuel llandling Accident as a basis"is redundant with the other radiation monitoring CDCs in this section and r,hould be deleted.
b._ The CDC: " Fuel pool designed without
- b. CDC Deleted protruding structures that could damage fuel if dropped," should be deleted. The licensee determined by analysis (FSAR Section 14.7.4.2) that if the Spent Fuel Pool (SFP) had a protrusion ofindeterminate shape (assumed to be a line load), and a Ibel assembly were accidentally dropped and struck the protmslon causing the maximum amount of damage to the fuel assembly, that the resulting radiological consequences would not exceed the limitations of 10 CFR Part 100.
c, The reference for the Auxiliary Exhaust System
- d. The Functional / System CDC: 'SFP area air is
- d. Revise CDC wording aligned to exhaust through the EBFS [ Enclosure Building Filn tton System) prior to release a
through the Unit I stack," should read; SFP area air is aligned to exhaust from the AES through the EBFS prior to release through the Unit I stack."
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B: SECTION 2.3, " FUEL liANDLINO ACCIDENT IN TIIB CONTAINMENT"
- 1. Additional comments on Section 2.3.5.2 of the Critical Design Characteristics
- a. In Section 2.3.5.2, " Containment Integrity and
- a. Revise CDC wording Radiation Control CSF [ Critical Safety Functions," the last CDC should be consistent with Section 2.2. Modify the last CDC to read:
"The radiation monitoring system monitors ventilation exhaust from the containment and
)
auxiliary buildings and alarms upon mdication of a fuel handling accident."
C: SECTION 2.4,' SPENT FUEL CASK DROP i
ACCIDENTS"
- 1. Additional Critical Design Characteristics
- a. Section 2.4.5.1, Functional / System CDC: "The
- a. Referenced system alignmer.t is only SFP area air is aligned to exhaust from the AES required when decay time is less than through the EBFS prior to release through the 60 days. Tech Specs require a Unit I stack."
minimum decay time of 12 months.
See 2a below,
- b. Section 2.4,5.1, Functional / System CDC: "The
- b. Validate as CDC radiation monitoring system alarms on a loss of shielding due to low water level in the fuel pool."
- c. Section 2.4.5.1 Functional / System CDC: "The
- c. Validate as CDC l
radiation monitoring system monitors the ventilation exhaust air from containment and auxili"/ buildings and alarms on indication of a breach of fuel."
- 2. Additional comments on Section 2.3.5.2 of the Critical Design Characteristics
- a. The CDC,
- Containment Integrity and Radiation
- a. Revise CDC wording Control CSF," should read. "Fuct fission product decay time at least one year " FSAR Section 14.7.5 is currently inconsistent with the requirements of Millstone Unit 2 Technical Specification (TS) 3.9.16.1. This TS wts changed to require a minimum one year of decay time.,
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D: Section 2.5, *llydrogen Accumulation in Containment"
- 1. AdditionalMitigation Systems
- a. Combustible Gas Cortrol System does not
- a. Ilydrogen Monitoring System CDCs, appear to be included as an interfacing system to include monitoring, readout &
required to mitigate the consequences <.f the alarm, will be derived from the accident accident. Section 6.2.5 of the NRC's Standard analyses for this event and validated.
Review Plan (SRP) states that combustible gas control systems should include instrumentation needed to monhor system or component performance under normal and accident conditions. The instrumentation should be capable of determining that a system is pet forming its intended function, or that a system train or component is malfunctioning and should be isolated. The instrumentation should have readout and alarm in the control room. The containment hydrogen monitor shall meet the requirements ofitem II.F.1 of NUREG 0737 and NUREG 0718, and the Appendix of Regulatory Guide 1.97.
- 2. Additional Comments on Section 2.5 of the CDCs
- a. Vahdate that a tracking program exists decomposition of organic materials exposed to which appropriately accounts for containment spray solutions are provided.
inventories exposed to containment Parsons should verify the inventories and spray.
assumptions given in Section 2.5.5.1.
E: Section 2.6, " Radiological Consequences of the Design Basis Accident"
- 1. Additional Comments on Section 2.6 of the CDCs,
- a. The primary containment leakage rate for the
- a. 0.5%/ day is the value used in the LOCA dose analysis should be based on the analyses and is consistent with the Tech containment leakage testing described la Spec value.
Chapter 6 of the FSAR. Therefore, the containment leakage testing section of Chapter 6 of the FSAR should be referenced. It should be noted that NUP.EG/CR-5640 lists the containment leak rate as 3.0% vol/ day for Millstone 2 instead of the reactor building rate of < 0.5%! day given as the CDC. The containment leak rate should be confirmed with the one given in Chapter 6 of the FSAR.
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