ML13330A372
| ML13330A372 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/06/1981 |
| From: | Baskin K Southern California Edison Co |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TAC-44128, TASK-1.C.1, TASK-2.D.1, TASK-2.E.4.2, TASK-2.F.1, TASK-2.K.3.02, TASK-2.K.3.03, TASK-2.K.3.09, TASK-2.K.3.30, TASK-TM NUDOCS 8108120144 | |
| Download: ML13330A372 (9) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUTGROVEAVENUE ROSEMEAD. CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER OF NUCLEAR ENGINEERING, August 6, 1981
'o (213) 572-1401 SAFETY, AND LICENSING Director, Office of Nuclear Reactor Regulation Attention: D. M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C.
20555 1h
$ NUOM REGSLAT Gentlemen:
Subject:
Docket No. 50-206 Response to Order Confirming Commitments for TMI Related Requirements San Onofre Nuclear Generating Station Unit 1
Reference:
- 1. Letter, D. M. Crutchfield, NRC, to R. Dietch, SCE, Order Confirming Commitments for TMI Related Requirements, July 7, 1981
- 2. Letter, J. G. Haynes,, SCE, to R. H. Engelken, NRC, July 7, 1981.
- 3. Letter, K. P. Baskin, SCE, to D. M. Crutchfield, NRC,
- Containment Purging and Venting, January 15, 1980
- 4. Letter, Robert W. Jurgensen, Westinghouse Ovners-;Gr'up,. to James R. Miller, NRC, WCAP-9804, March 13,"1981
- 5. Letter, Robert W. Jurgensen, Westinghouse Owners' Grouptb Stephen S. Hanauer, NRC, Westinghouse Owners'-Group-Response to Item I.C.1 of NUREG-0737, December 15, 19801
- 6. Letter, Thomas Anderson, Westinghouse, to D. G. Eisenhut, NRC, Letter Number NS-TMA-2318, September 26, 1980
- 7. Nuclear Regulatory Commission Memorandum, Frank C. Cherny to Robert J. Bosnak, July 14, 1981, Meeting with EPRI and PWR Utilities to Discuss Status of EPRI/PWR Safety and Relief Valve Qualification Program Development Prusuant to Item II.D.1, NUREG-0737, July 22, 1981 Reference 1 forwarded to us an Order to satisfy the specific requirements described in the Attachment to the Order.
The scheduled dates in the Attachment to the Order are the original dates set forth in NUREG-0737.
18120144 81063,0 PDR ADOCK 050002061 P
PDR!
D.
August 6, 181
- However,
'as discussed in Reference 1 and the Order, you determined that our proposed schedule exceptions to those set forth in the Attachment to the Order were acceptable and we should satisfy the specific requirements described in the Attachment to the Order as early as practicable but no later than 30 days after the effective date of the Order.
The purpose of this letter is to advise you that the specific requirements described in the Attachment to the Order were satisfied prior to receipt of the Order except for Item II.F.1(a). of this letter provides a description of the noble gas monitor and iodine/particulate sampling and analysis system required by II.F.1.
Our letters of January 17, 1980 and June 17, 1981 provided a description of our interim measures for meeting the requirements of NUREG-0737-II.F.1.
Since the system described in is not required to be operational until January, 1982, there are no deviations from the staff's requirements at this time.
The system was installed during the last refueling/ maintenance outage, but has not, as yet, been made fully operational.
During startup activities, it was determined that isokinetic flow conditions could not be achieved in the low radiation/high flow sample line.
Test measurements indicated a maximum flow rate of 1.6 SCFM.
The flow rate necessary to establish isokinetic sampling conditions is 2.0 SCFM.
We are currently evaluating potential modifications to determine the final system configuration and capabilities.
In addition to the above information, we are submitting the following information to clarify how we have met certain items of the Order.
- 1.
Item II.D.1(b) - Performance Testing of RV/SRVs.
A program for the qualification of PWR block valves has been developed by EPRI, but has not been implemented or submitted to the NRC staff.
We are currently awaiting final resolution of discussions with the
- NRC, EPRI,- and other utilities as to whether the program is required.
The status of this item is discussed in Reference 7. Final disposition of this item will be made following those discussions.
- 2.
Item II.E.4.2(b) -
Containment Isolation.
Reference 3 provided a statement that the containment purge valves will be maintained closed until the reactor is in a cold shutdown condition.
In addition, the manual isolation valves are closed and locked during power operation.
Prior to return to power from:the last refueling/
maintenance outage, surveillance procedures were modified to verify, at least each 31
- days, the manual isolation valves are sealed (i.e., closed and locked).
D.
August 6, 1981
- 3.
Item II.K.3.3 - SRV/SV Failures and Challenges.
The requirements of the Order appear to be inconsistent with II.K.3.3 as stated in your May 7, 1980 letter, which does not request historical data.
We have committed to provide data on all future SRV/SV failures and challenges.
- However, as part of the requirements of NUREG-0737 II.K.3.2 - Report on Overall Safety Effect of Power-Operated Relief Valve Isolation System, historical data on SRV/SV failures and challanges was provided to you by the Westinghouse Owner's Group (Reference 4).
San Onofre Unit 1 is identified as plant #18 in that report.
- 4. Item II.K.3.9 -
PID Controller Modification.
The two PORVs at San Onofre Unit 1 have two different types of controllers; one has derivative control, the other does not.
The required modification was made to the controller with derivative control prior to the unit being returned to power from the last refueling/maintenance outage.
However, upon return to power, the controller was placed in "manual" following spurious actuation of the PORV.
These events were reported in Reference
- 2.
The PID controller will remain in the manual mode of operation until it is replaced with a controller similar to the other PORV controller.
- 5.
With regard to Items I.C.1 - Accident Procedures, II.K.3.2 -
PORV/SV Failures and II.K.3.30 -
SB LOCA Methods; these items have been addressed by the Westinghouse Owner's Group, of which Southern California Edison is a member.
Since the Owner's Group has addressed these items on our behalf (References 4, 5 and 6),
we believe no additional information is required by your Order.
If you have any questions, please let me know.
Very truly yours,
ENCLOSURE 1 DESCRIPTION OF MODIFICATIONS
- 1. Extended range radiation monitoring equipment will be added to measure post accident effluent gas radiation levels.
This equipment will be designed to function during accident conditions as well as during normal operating conditions.
The equipment to be installed will comply with Regulatory Guide 1.97 Rev. 2.
- 2. Extended range equipment to be added will include the following:
o Noble Gas Vent Stack Effluent Radiation Monitors o
Atmospheric Steam Dump and Safety Valve Header Radiation Monitor
- a.
Noble Gas Effluent Monitor A single noble gas effluent monitoring system will be added to the SONGS 1 vent stack.
The vent stack is presently a final release point for the following plant areas:
o Reactor Auxiliary Building o
CVI Waste Gas Treatment Building o
Spent Fuel Storage Area o
Air Ejector o
Containment Building Noble gas effluent monitors with a range of 10-7 to 105 Ci/cc (Xe-133) will be provided.
Multiple monitors will be required to f cover this range.
Continuous indication and recording will be provided in the Main Control Room (MCR),
which provides for supplying a signal to the Health Physics Computer to be installed in the SONGS 2 Technical Support Center (TSC).
Main system components to be installed include the following (see sketch A):
- 1), Isokinetic Sample Nozzles
- 2) Sampling Rack
- 3) Sample Conditioner
- 4)
Detector Assembly
- 5) Microprocessor
- 6) Readout Units
-2 The isokinetic sample nozzle assembly, mounted on the vent stack, will provide a stack effluent sample to the sample conditioner and sampling rack skids, located in a plant area near the vent stack.
It may be necessary to provide heat tracing for the sample lines for the isokinetic nozzles to the sampling racks/sample conditioner.
Detector assembly skids, located in the plant area, willk receive conditioned samples and provide measurement signal information to the microprocessor control unit and readout devices located in the HVAC equipment room and MCR, respectively.
Skid mounted assemblies will be mounted inside environmentally controlled enclosures.
Readout devices will include continuous indication and recording of noble gas concentration per unit volume for each dtector as well as total rate of release from the vent stack.
- b. Steam Dump and Safety Valve Monitors Radiation monitoring systems will be installed to measure effluent radiation at the atmospheric steam dump and safety valves.
This will be done indirectly by measuring radiation at each of two steam dump and safety valve headers (see P&ID 568773).
The monitors to be installed will directly measure the radiation passing through the header pipe.
They will be calibrated for the resulting radiation the monitor will see based on the maximum gas effluent radiation at this release point.
System components will include the following (see sketch B):
- 1) Radiation Sensor Assembly
- 2) Readout Electronics Each monitor will be located outside the containment.
High and low range radiation sensors will be mounted so that they will directly sense the radiation emanating from the header pipe.
Measurement signal information will be transmitted directly to readout devices, located in the MCR with provisions for transmitting signal to the health physics computer at SONGS 2,
TSC.
Readout devices will consist of continuous indication and recording of activity in rads/hr for high and low range channels.
- 3.
The system will be powered from independent 120 VAC vital bus systems and 120 V emergency power sources.
- 4.
The power source for the system will be supplied from the 120 VAC buses.
Effluent system sample/conditioner/detectors will be supplied from emergency 120 VAC sources.
The microprocessor and readout device will be supplied for 120 VAC vital buses.
Interconnecting conduit and cable for instrumentation and controls will be provided for the following:
-3 a)
Noble Gas Effluent Monitors
- 1) The sampling rack to the Microprocessor Control Unit (MCU) in the HVAC equipment room.
- 2) The sample conditioner to the MCU.
- 3) The gas detector to the MCU.
- 4)
The MCU to the sampling control, readout and recorder units in the MCR.
- 5)
The readout units to the TSC.(
- 6) Heat tracing of sample lines to isokinetic nozzles.
b) Steam Dump and Safety Valve Monitors
- 1)
The radiation sensor units to the readout units in the MCR.
- 2)
The readout units to the recorder in the MCR.
SIGNIFICANT ASSUMPTIONS AND CRITERIA
- 1.
The extended range radiation monitoring equipment to be added shall comply with requirements of Regulatory Guide 1.97, Rev.
2 and ANSI N320-1979.
- 2.
The range capacity of individual system monitors shall overlap by a factor of ten.
- 3. The existing effluent monitoring system covering normal operating ranges will be retained.
- 4. It is assumed for the effluent monitoring systems, that extended range radiation measurements at individual sources that contribute to the common release point are not necessary.
- 5.
Since iodine gaseous and particulate effluent monitoring systems for the accident conditions are not considered to be practical at this time, this capability will be provided with sampling conducted as part of the noble gas effluent monitoring system by absorption on a filter media, followed by onsite laboratory analysis.
- 6.
All electrical work will be designed as safety related.
- 7. Redundancy and separation of power sources shall be maintained for train aligned systems.
- 8. Qualified equipment shall be provided for all safety related systems.
-4
- 9.
Routing raceway and cable for "G" train circuits through the 4 kV switchgear room should be avoided.
- 10. Physical and electrical independence shall be maintained for redundant circuits.
- 11.
No missile protection is required for the raceway installation.
- 12. Additional loads added to the 120 VAC vital buses will not cause any equipment overloads.
SKETCH A HI-GH-RANGE NOBLE GAS EFFLUENT RADIATION MONITORING SYSTEM (I REQUIRED)
EFFLUENT FLOW RETURN LINE ISOKINETIC NOZZLES* 2 FT/t 120VAC VITAL BUS 120 VAC VITAL BUS(toAMPS)
I-' IP SAMPLIt46 (AMP)
WIDE-RANGE 7 -
1 RACK GAS DETECTOR s I t
-* 0.06 ag FT /MAIN PURGE SK.
SAMPLING CONTROLS PURGE PURGE AIR OUT SAMPLE CONDITIONER VEN 5TCKSKID
- READ OUT U1Pt VENT STACK.
LOCATE PER ANSIN13.1 120VAC VITAL BUSR
- by SCt(IfrERcow.ICt MICROPROCESS.
Tsc IPItIO WIRING)
('
AMPS)
INTERFACE 120VAC VITAL BUS (2NAGPS) 120 VAC VITAL Bus (I AMP)
(TYC. GENERAL ARTOMIC SYSTM)
GR8 G-3-IO
SKETCH B ATMOSPHERIC STEAM 'DUMP/ sAFETY VALVE HIGH-RANGE EFFLUE~iT RADIATIOtI MONITORIN'G SYSTEM (I SYSTEM REQUIRED 7
,PEP, H-EADER)
'% ATMOSPIAERIC STEAM DUMP/SAFETY VALVE HEAD)ER LOW AND HIGH RANGE.
(RD IA( RD2A)DETECTOR ASSEMBLIES q") 0MOUNTrED IWSIDE RE AC70R CONTAINAET 0
)HNCLUDSMAll4GCO NECTORS, 0~~~~~
NIEAT SHIRINIKABLE SLEEVES BY GA LWADHG AG COWDUrr (BY SCE)
READOUTS (RP -1 +
4 2
MOUNTED IN NIM BI" 11A REACTOR CONTROL ROOMA (POWER SUPPLY MOUNTED (TYP GENERAL ATOMIC SYSTEM SHOWN)
ON REAR OF BIN) 0 RECORDER RG-g5U.-PLIED BY SCE U0 UAB SELDEN NO. 9244 OR EQUAL MULTIPIN RECORDER)
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