ML20039C182
| ML20039C182 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon, 05000232 |
| Issue date: | 12/21/1981 |
| From: | Hoch J PACIFIC GAS & ELECTRIC CO. |
| To: | |
| References | |
| NUDOCS 8112290001 | |
| Download: ML20039C182 (4) | |
Text
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD i' ': g e : c e OI EC 28 m;:43
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In the Matter of
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'1.
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Docket Nos. 50-275
'j '. m PACIFIC GAS AND ELECTRIC COMPANY
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50-323 "D
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(Diablo Canyon Nuclear Power
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Plant, Unit Nos.1 and 2)
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(Full Power Proceeding)
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me AFFIDAVIT OF JOHN B. HOCH STATE OF CALIFORNIA
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BECENIO P
DEC28196W '9
) SS CITY AND COUNTY OF SAN FRANCISCO
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S-s e#r3 #
9 M
Cu JOHN B. HOCH, being duly sworn, deposes and says:
N My name is John B. Hoch.
I am Manager of Nuclear Projects for Pacific Gas and Electric Company (PGandE).
I hold a Bachelcr of Science degree in Mechanical Engineering.
I am a registerad Mechanical Engineer and Nuclear Engineer in the State of California.
I have over twenty-one years of power plant related experience of which ten years were nuclear related and eight years of which have been directly relatec to the Diablo Canyon Power Plant.
This afficavit relates to Joint Intervenors Contention 12 as set forth in the ASLB Prehearing Conference Order of February 13, 1981, and also to Clarified Combined Cententions 8 anc 9 of the Joint Intervenors' Statement of Clarified Contentions of June 30, 1981.
I attest that:
1)
The pressurizer of each unit of the Diablo Canyon Plant is equipped with three pressurizer power-operated relief valves (PORVs) and three associated block valves. Each PORV is equipped with one associated block valve.
2)
The PORVs are designed to relieve steam to limit the maximum pressure in the reactor coolant system.
The functinn nf the PORVs is to prevent unnecessary npening of the pressurizer safety valves and to provide a backup means of depressurization and nyer-pressure protection. g 99 8112290001 811221 b' \\
DR ADOCK 03000275 PDR
3)
One"PORV is needed to accomplish the intended function of the PORVs. A second PORV is installed to provide redundancy. The third PORV performs no safety-related function and was installed to provide the capability for full load rejection without tripping the reactor.
4)
One separate block valve (BV) is installed upstream of each of the PORVs. The function of the BV is to permit isolation of a PORV for testing or maintenance, or permit isolation of a leaking or f ailed-open PORV.
5)
All three of the BVs have been classified as components important to safety and meet applicable safety-grade design criteria. The valve bodies for all three PORVs have been classified as components important to safety and meet applicable safety-grade design criteria. The PORVs and BVs have been classified in accordance with the requirements of Design Class I, Lode Class I as described in the FSAR, Tables 3.2-1, 3.2-2, 3.2-3, and 3.2-4.
Similarly, these valves were seismically qualified for the Hosgri event.
I The applicable safety-grade design criteria to which these valves have been designed are listed in statement 7 of this affidavit.
The instruments and controls of two safety-grade PORVs and 6).
of all three block valves have been classified as components important to safety and meet applicable safety-grade design criteria, indicated in statement 7 of this affidavit, as follows:
(A) The devices through which motive and control power components for the PORVs and their associated block valves are connected to emergency buses have been qualified in accordance with applicable safety-grade requirements.
(B)
Normal plant instrument air supply (motive power) to each valve is provided with a dedicated high pressure nitrogen backup system capable of operating the valves 140 times.
This backup system is classified as safety-related and is not dependent on any external power.
(C) Power for control components of the three PORVs is provided from three Class 1E, 125 volt DC distribution panels which are redundant to car.h other. Power for motive and control for the three associated block valves is provided from three Class lE, 480 volt AC motor control centers which are redundant to each other.
A 7)
The safety-grade design criteria that are met by the three PORVs, three associated block valves, and the instruments and controls for.two of the three PORVs include the following General Design Criteria (GDC): GDCs 1, 2, 4, 12, 13, 19, 20, 21, 22, 23, 24, and 29. The applicability of and compliance with these criteria has been determined in accordance with the requirements identified in the Standard Review Plan,.Section 7, Table 7-1 (Rev. 2, July 1981).
8)
Proper operation of PORVs and BVs is not required to miticate the consequences of any design basis accident considered in the FSAR. Analyses of design basis accidents are contained in Chapter 15 of the FSAR.
9)
Under normal conditions, the PORVs remain closed.
In the FSAR accident analyses, credit has not been taken for the automatic opening of the PORVs.
10)
If the third PORV, which meets scfety-grade design criteria except for its instruments and controls, f ails closed in its normal position, its pressure-relief function may still be performed by either of the other two PORVs, whose instruments and controls do meet applicable safety-grade design criteria.
If this third PORV f ails open af ter actuation, it may be isolated by its associated block valve, which does meet applicable safety-grade design criteria. No credible failure mode associated with the non-safety grade components of the third PORV's control system would adversely affect the function of any safety grade components.
- 11) An unisolated stuck-open PORV during a design basis accident considered in the FSAR would not result in core damages as demonstrated by analyses contained in Chapter 15 of the FSAR and in WCAP-9601. Therefore, the consequences of f ailure of the third PORV in either the closed or the open position during design basis accidents considered in the FSAR have been cemonstratec by analyses to be insignificant.
- 12) The Electric Power Research Institute (EPRI) has established a performance testing program to obtain full scale data on the operational performance of valves, including relief valves, to operate under normal and accident conditions.
- 13) A Masoneilan series 20,000 mcdel relief valve representative of Diablo Canyon was tested by EPRI.
Relevant detailed information on EPRI steam tests of this relief valve wes provided as testimony during the Diablo Canyon Low Power Proceedings. Other EPRI tests on this Masoneilan valve have been completed following the Diablo -
r Canyon Low Power Hearings. This valve passed applicable
- testing criteria and fully operated on demand under the EPRI test conditions which included full pressure steam, water, transition and loop seal simulation conditions. The conditions of these tests are representative of potential plant conditions, described in the FSAR, which may be encountered by Diablo Canyon valves.
14 ) A Velan model B10-30548-13MS block valve representative of Diablo Canyon was tested by EPRI. Relevant detailed information on block valve testing performed by EPRI has been provided as testimony during the Diablo Canyon Low Power Proceedings. This Velan block valve fully opened and closed on demand in the EPRI 'asts, which included specific test conditions representative s' potential Diablo Canyon plant conditions.
- 15) The NRC requires that utilities submit plant-specific reports by July 1982 to document the applicability of the EPRI valve performance testing program to each specific plant.
The NRC also requires that a report for block valve qualification be submitted by July 1982.
(September 29, 1981 NRC letter to Licensees from Mr. D. G. Eisenhut and NUREG-0737.)
- 16) Results of testing performed by EPRI on relief and block valves is scheduled to be documented formally by EPRI by July 1982.
PGancE will prepare plant-specific reports, to be submitted to the NRC as required, inclucing qualification data on block valves and analyses of results of the EPRI valve performance testing program, for applicability to Diablo Canyon.
- 17) Based on the information presented above and that presented in separate affidavits by Edward M. Burns and Raymond J.
Skwarek of Westinghouse, the PORVs and associated block valves, which are part of the reactor coolant pressure boundary, as well as their instruments and controls, comply with applicable regulatory requirements, including General Design Criteria 1, 14, 15, and 30.
8!-
JOHN B. H Subscribed and sworn to before me this 21st day of December, 1981
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R Thechora Cocke, Notary Public in and for the City and County of San Francisco, State of California My Connission expires January 28, 1985
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