ML16341B530
| ML16341B530 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 02/24/1981 |
| From: | Bradley Jones NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| To: | Atomic Safety and Licensing Board Panel |
| References | |
| ISSUANCES-OL, NUDOCS 8102260124 | |
| Download: ML16341B530 (22) | |
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~Jgg~~fggy UNITED STATES OF AMERICA Vgy NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING.BOA In the Matter of PACIFIC GAS AND ELECTRIC COMPANY
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(Diablo Canyon Nuclear Power
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Plant, Units Nos. I and 2)
Docket Nos
-27
.L.
-323 O.L.
REQUEST FOR ADMISSIONS BY JOINT INTERVENORS The NRC Staff requests Joint Intervenors within 15 days after service of this request to make the following admissions for the purposes of this action only and subject to all pertinent obiections to admissi-bility which may be interposed at trial.
That each of the following numbered statements is true.
A.
Mater Level Indicator 1.
There are indirect indicators of water level, such as core exit thermocouples, which would indicate inadequate core cooli.ng at the Diablo Ca'nyon Nuclear Facility (DCNF).
2.
There are indirect indicators of water level, such as saturation
- meters, which would indicate conditions which could lead to inadequate core cooling at the DCNF.
3.
Monitoring of the indirect indicators mentioned in state-ments A. 1 and A.2 above has been processed for display and incorporated into emergency procedures such that the monitoring can provide equivalent information to that
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which would be obtained from direct water level indicators at the DCNF.
4.
Core exit thermocouples provide an indication of the magnitude of steam superheat when core is uncovered.
5.
Core exit thermocouples provide an indication that the core is covered when no superheat exists.
6.
The normal water level range in the reactor coolant system during operation is within the pressurizer.
7.
The normal water level range in the reactor coolant system during operation is maintained by the pressurizer level control system.
8.
For transient and accident conditions resulting in low coolant inventory, the low pressure safety injection systems are initiated on low pressure signal to reflood the primary system.
9.
For transient and accident conditions resulting in low coolant inventory, the high pressure safety injection systems are initiated on a low pressure signal to reflood the primary system.
10.
Reactor vessel water level is not a necessary input to the safety injection system since the corrective action is initiated by a low pressure signal well in advance of core uncovering.
ll.
Reactor water level instrumentation, if installed, will be used for monitoring and operator actions only.
12.
The instrumentation available at Diablo Canyon that could indicate inadequate core cooling includes:
a)
Core exit thermocouples which indicate coolant superheat associated with excessive fuel cladding temperature.
b)
Reactor coolant pressure sensors which provide inputs to compute the margin to coolant saturation condi-tions.
c)
Cold and Hot leg resistance temperature detectors (RID's) which provide inputs to compute the margin to coolant saturation conditions.
d)
Subcooling meters which display the margin to satura-tion.
e)
Reactor coolant pump current which provides an indication of increasing coolant quality while the pumps are running.
13.
The licensee has proposed emergency procedures for inade-quate. core cooling which rely on the information available from the core exit thermocouples, reactor coolant system
- pressure, reactor vessel outlet temperature and saturation (subcooling) meters to identify the approach and existence of inadequate core cooling.
14.
The licensee has proposed emergency procedures for inade-quate core cooling which specify the operator actions required to prevent or recover from inadequate core cooling.
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15.
Procedures to detect inadequate core cooling can be, devloped for Diablo Canyon without reliance on direct water level measurement.
16.
Inadequate core cooling emergency procedures based on instrumentation, similar to the Inadequate Core Cooling Emergency Procedure's which will be provided prior to fuel load at DCNF, have been found acceptable for other PWR's while a level measurement system to further enhance the operational safety is being developed.
17.
The Westinghouse Differential Pressure Measurement of Reactor Vessel Water level provides a method of water level measurement which will meet all current applicable NRC regulations.
18.
The Combustion Engineering Heated Junction Thermocouple System (HJTC) provides a method of water level measurement which will meet all current applicable NRC regulations.
19.
The EPRI sponsored Noninvasive Water level Measurement Technique (Neutron Detectors) provides a method of water level measurement which will meet all current applicable NRC regulations.
20.
The DAVCO Microwave Liquid Level Gauge provides a method of water level measurement which will meet all current applicable NRC regulations.
21.
The overall reduction in risk to the public from the DCNF should be a factor of 400 to 1500 if the plant is operated
at 5X power for 6 months compared to continuous full power operation.
I 22.
The risk to the public from the DCNF operations during low power testing as compared to full power will be reduced as a result of the reduced fission product inventory.
23.
The fission products inventory produced during low power testing of a PWR at 5X power for 6 months is a least 20 times less than the fission products inventory produced during continuous full power operation.
24.
The risk to the public from DCNF operations during low power testing will be reduced as compared to full power as a result of the substantially greater time to correct malfunctions in case of an accident because the decay heat level is greatly reduced.
25.
The time available to deal with accident sequences during low power testing as compared to during full power opera-tion is increased from several minutes to 10 or more hours::
'I 26.
Turbine Trip initiated accident sequences are irrelevant during low power testing of the DCNF since the turbine will not be on line during low power testing.
27.
A total loss of feedwater event is inconsequential because passive system heat losses are sufficient to remove all heat generated after steam generator boiloff during low power testing.
28.
In addition to the example identified in A.25 and A.26, there are other accident sequences which are irrelevant during low power testing, 29.
Additional level instrumentation would not materially add to risk reduction at low power since large amounts of time would already be available to diagnose and mitigate potential severe accident sequences.
B.
Emergency Planning 1.
The licensee has an emergency plan which will be in effect i'uring low power testing at the DCNF.
2.
San Luis Obispo County has emergency plans which will be in effect during low power testing at the DCNF.
3.
The fission product inventory accumulated during low power testing is a small fraction of the amount of fission product inventory that accumulates during full power operation.
4.
Any accident occurring during low power testing would release a fraction of. the existing fission product inven-tory at the DCNF.
5.
Off-site doses from an accident during low power testing would be a small fraction of the doses from a similar accident during full power at the DCNF.
6.
County plans now in force do contain provisions for taking protective measures offsite at the DCNF.
0
7.
The present county emergency plans would provide for shelter and/or evacuation for large scale releases, if they could occur, during low power testing of the DCNF.
8.
The present county emergency plans provide for lesser actions then shelter and evacuation, such as notification, for lower level releases from the DCNF during low power testing, if such releases occur.
9.
The licensee's present emergency plan requires immediate notification of the county governments surrounding the DCNF of any releases from that facility.
10.
The present county emergency plans contain quantified release levels entitled Emergency Classes which determine what emergency procedures are to be implimented for releases at the DCNF.
ll.
Additional offsite protective actions will not signifi-cantly reduce the effects of any release from accidents at the DCNF which occur during low power testing.
C.
Pressurizer.-Heater Power Supplies 1.
The Pressurizer Heaters are a resistive load.
2.
There is no significant voltage transient experienced by the diesel generators upon loading the heaters as there would be if a similarly rated motor load were to be energized.
3.
If a safety injection actuation signal (SIAS) is present, the heaters cannot be loaded onto the diesel generators until the SIAS has been reset.
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If the heaters are energized by the diesel generators, they will be automatically tripped upon occurrence of an SIAS.
5.
The circuit breakers used to interface the motive and control power to the heaters from the emergency buses are safety grade.
6.
The same safety grade circuit breakers mentioned in C.5 above (52-1G-72 and 52-1H-74) are the devices used to trip the heaters upon SIAS.
7.
Overall diesel generator
- loading, as well as specific heater
- load, are provided as readouts on the main control board.
8.
Actual loading of the pressurizer heaters will not be attempted unless sufficient diese'I generator ~i.e., onsite emergency power supply) capacity exists (207 kw).
9.
Approved written procedures will be used by plant operat-ing personnel for use of the pressurizer heaters.
D.
Block Valve Testing 1.
Primary system PORV block valves (block valves) are not used for normal shutdown of a pressurized water reactor.
2.
Safety valves are to be used at DCNF for overpressure protection.
3.
There are three safety valves in the primary, system at DCNF.
~1 4.
Relief valves (PORV's)'re used as a backup to operator action to prevent overpressurization during power shutdown and power startup.
5.
DCNF has relief valves (PORV's) in its primary system.
6.
Even if the relief valves, (PORV's) safety valves, and block valves were stuck open, the time available to deal with accident sequences during low power testing as compared to full power operation is increased from several minutes to 10 or more hours.
7.
Block valves are not designated as safety grade equipment, however they are designated safety related equipment.
8.
Block valves serve as a means to isolate PORV's.
9.
There is an indicator in the control room which shows whether a
PORV is open or closed.
10.
Safety valves have never failed to perform their function of overpressure protection in a nuclear power plant.
The NRC Staff requests the Joint Intervenors, if they do not admit that each of the abave statements are true, to identify which statements above or portions thereof, they do not admit as 'true.
Respectfully submitted, Bradley W. Jon Counsel for NRC Staff Dated at Bethesda, Maryland this 24th day of February, 1981
f
UNITED STATES OF AMERICA NUCLEAR REGULATORY COl HAMI SSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of
)
)
PACIFIC GAS AND ELECTRIC COMPANY
)
)
(Diablo Canyon Nuclear Power Plant,
)
Units Nos.
1 and 2)
)
Docket Nos.
50-275 O.L.
50-323 O.L.
CERTIFICATE OF SERVICE I hereby certify that copies of REQUEST FOR ADMISSIONS BY JOINT INTER-VENORS in the above-captioned proceeding have been served on the following by deposit in the United States mail, first class or, as indicated by an
- asterisk, through deposit in the Nuclear Regulatory Commission's internal mail system, this 24th day of February, 1981.
- Elizabeth S. Bowers, Esq.,
Chairman Atomic Safety and Licensing Board Panel U.S. Nuclear Regulatory Commission li'ashington, D.C.
20555
- Mr. Glenn 0. Bright Atomic Safety and.Licensing Board Panel U.S. Nuclear Regulatory Commission 1'ashington, D.C.
20555
- Dr. Jerry Kline Atomic Safety and Licensing Board U.
S. Nuclear Regulatory Commission Nashington, D.
C.
20555 Philip A. Crane, Jr.,
Esq.
Pacific Gas and Electric Company P.O.
Box 7442 San Francisco, California 94106 Mrs. Elizabeth Apfelberg 1415 Cozadero San Luis Obispo, California 93401 Mrs.
Raye Fleming 1920 flattie Road Shell Beach, California 93449 Mr. Frederick Eissler Scenic Shoreline Preservation Conference, Inc.
4623 More Mesa Drive Santa Barbara, California 93105 Mrs. Sandra A. Silver 1760 Alisal Street San Luis Obi spo, Cal iforni a 93401 Mr. Gordon Silver 1760 Alisal Street San Luis Obispo, California 93401 Richard B. Hubbard MHB Technical Associates 1723 Hamilton Avenue - Suite K
San Jose, California 95125 Andrew Baldwin, Esq.
124 Spear Street San Francisco, California 94105
Paul C. Valentine, Esq.
321 Lytton Avenue Palo Alto, California 94302 Harry H. Willis Seymour 5 Willis 601 California, Street, Suite 2100 San Francisco, California 94108 John R. Phillips, Esq..
Simon Klevansky, Esq.
margaret
- Blodgett, Esq.
t~arion P. Johnston, Esq.
Joel
- Reynolds, Esq.
Center for Law in the Public Interest 10203 Santa flonica Boulevard Los Angeles, California 90067 Arthur C. Gehr, Esq.
Snell 5 Wilmer 3100 Valley Center Phoenix, Arizona 85073 Janice E. Kerr, Esq.
Lawrence q. Garcia,,Esq.
350 HcAllister Street San Francisco, California 94102 Nr. James
- 0. Schuyler-Nuclear Projects Engineer Pacific Gas 5 Electric Company 77 Beale Street San Francisco, California 94106 John Harrs Yanaging Editor San Luis Obispo County Telegram-Tribune 1321 Johnson Avenue P. 0.
Box 112 San Luis Obispo, California 93406 Bruce Norton, Esq.
3216 North 3rd Street Suite 300
- Phoenix, Arizona 85012 Davis S. Fleischaker, Esq.
Suite 709 1735 Eye Street, N.W.
hashington, D.C.
20006 Byron S. Georgiou Legal Affairs Secretary Governor's Office State Capitol Sacramento, California 95814 Herbert H. Brown HILL, CHRISTOPHER 5 PHILLIPS, P.
C.
1900 N Street, N.W.
Washington, D.C.
20036 Richard E. Blankenburg, Co-publisher hayne A. Soroyan, News Reporter South County Publishing Company P. 0.
Box 460 Arroyo Grande, California 93420
+Atomic Safety and Licensing Board Panel
~,
U.S. Nuclear Regulatory Commission Washington, D.C.
20555
- Atomic Safety and Licensing Appeal Panel U.S. Nuclear Regulatory Commission Washington, D.C.
20555
- Secretary U.S. Nuclear Regulatory Commission ATTN:
Chief, Docketing 8 Service Br.
Washington, D.C.
20555 B~ adle W. Jones Counsel for NRC Sta ff
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