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Jersey Central Power & Light Company %(J MADISON AVENUE AT PUNCH BOWL ROAD e M.ORRISTOWN, N.J.07960
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w October 30, 1975 g
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t Mr. George Lear, Chief NOV3 19757 m Operating Reactors Branch #3
.u m Division of Reactor Licensing y
United States Nuclear Regulatory Commission rM Washington, D. C.
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SUBJECT:
Oyster Creek Nuclear Generating Station Docket No. 50-219 Suppression Pool Dynamic Phenomena 1
Dear Mr. Lear:
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'Ihc following is in response to your 1ctters of February 15, 1975 and April 17,1975. These letters requested that information relative to our containment be submitted to you. We have previously responded to your requests with our May 6,1975 letter which provided a preliminary schedule for addressing the concerns expressed in the above two 1ctters.
Our May 6 letter was supplemented by our July 3,1975 letter which stated that our schedule would be delayed for reasons discussed in a letter from Mr. I. F. Stuart of General' Electric to Mr. R. L. Tedesco of the NRC, dated June 13, 1975. As a result of a meeting with your staff on July 17, 1975, General Electric submitted a Status Report on the Mark I Containment in a Ictter from Mr. I. F. Stuart to Mr. A. Giambusso.
We submitted a Ictter to you regarding thi.s status report on August 1, 1975.
General Electric has submitted the Mark I Containment Evaluation Short Term Program - Final Report, NEDC 20989, Volumes I, II, III, IV, and V by a letter from Mr. I. F. Stuart to Mr. R. S. Boyd, NRC, dated October 6,1975.
The objective of this Short Term Program was to confirm that during a loss of coolant accident there would not be a loss of containment function on the Oyster Creek plant. Considering the satisfactory results of our in-vestigation to this time, as reported in NEDC 20989, we believe that reason-abic assurance exists that the public health and safety will not be endangered during the nyster Creek p.lant's continued operation while the long-term in-depth evaluation work continues. The scope of this. Long Term Program is out-lined in an attachment to this letter.
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6 12596 9604180301 960213
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h Mr. George Lear, Chief Page 2
- We suggest a meeting with the NRC Staff at which time a more detailed dis-cussion of the proposed I.ong Term Program could be held. This would_also be an appropriate time to evaluate the results of the Short Term Program.
The proposed meeting would be conducted with all other members of the Mark I Containment Owners Group and will be arranged by a representative of that group.
Enclosed are three signed originals e d thirty-seven copies of this letter.
Very truly yours,
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Ivan R. Finfrock, Jr.
Vice President pdd At tachment STATE OF NEN JERSEY )
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C0tNTY OF MORRIS
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Sworn to and subscribed before me this th d ay of Cc.h /<o 19 75 d
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MARK I CONTAINMENT EVALUATION - LONG TERM PROGRAM The Long Term Program has been developed to address pool dynamic loads associated with LOCA and relief valve blowdown events.
It consists of a combination of tests, analyses, and the development of acceptance criteria by which the design basis can be assessed. A parallel effort of development of potential modifications will be included so that they
'will be ready if required. The objective of the Long Term Program is to verify 1 that the containment is capable of meeting agreed-upon criteria and that it will function as intended for a forty-year-life.
This pro-gram is being undertaken as a joint effort by the ad hoc BWR Mark I Containment Owners Group.
It will be conducted on a generic basis to the greatest extent possible to minimize the time to achieve an accept-able overall uniform solution.
The activities of the Long Term Program include the evaluation of LOCA dynamic test data already obtained by GE and their licensee, together with a series of in-plant and out-of-plant tests supported by analytical programs to identify the phenomenological and structural characteristics of. the Mark I containment. Specific activities are listed below with a brief summary of their objectives, expected completion schedule, and description of their content.
RELIEF VALVE DISCHARGE RELATED ACTIVITIES 1.
In-Plant Test of S/R Valve Discharge for Torus Pressure and Strain Measurements, Discharge. Pipe Pressure and Water Level Measurements, and Consecutive Valve Actuation Measurements.
Schedule:
4th Quarter 1975 Objective; To establish a generic basis for and to refine the phenomenological model used to predict relief valve blowdown loads.
Description :
Conduct a series of single, multiple, and varying con-secutive actuation tests in one plant equipped with extensive torus strain and pressure instrumentation; S/R valve discharge line water level and pressure instrumentation.
2.
Select Plants for Torus Stress Test during Safety / Relief Valve ischarge.
Schedule:
4th Quarter 1975 Objective:
Define the plants appropriate for relief valve strain gage testing.
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Description:==
Establish plant selection criteria.
Evaluate preliminary test results and ensure that an adequate number of plants are being tested.to include applicability to.all plants.
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Mark.I Containment Evaluation -
Long Term Program Page 2 3.
Strain Gauge Testing in Representative Plants'.
Schedule:
Start 4th Quarter 1975 - Complete 3rd Quarter 1976 Objective:
Obtain direct torus shell strain measurements associated with relief valve actuations to demonstrate structural adequacy.
Descrip tion: Perform tests at several representative plants to adequately cover all Mark I designs.
Install strain gauge measurement instrumentation on the torus exterior surface. Perform single and multiple valve tests and establish fatigue life adequacy for testing plants and plants of common type utilizing these data.
4.
Relief Valve Mitigating Fix (Load Reduction) Testing.
Schedule:
1st Quarter 1976 Objective:
Provide quantitative evaluation of different RV discharge devices in small scale for scaling potential devices that may be backfittable to Mark I.
This is a backup mitigating fix being investigated in parallel with in-plant tests so that a device would be available if it should be needed later.
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Description:==
Design various load mitigation devices on a sub-scale basis.
Fabricate and install at the Moss Landing Test Facility and perform appropriate tests to obtain relative performance.
5.
Relief Valve Consecutive Actuation Transient Analysi,s.
Schedule:
3rd Quarter 1976 Objective:
Refine analytical methods for predicting discharge pipe pressure and stress amplification features associated with consecutive relief valve actuations.
Description :
Develop predictive model and verify with results from test data obtained in Item Number 1 above.
Establish methods for applying to all Mark I containments.
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Mark.I Containment
- Evaluation -
Long' Term Program Page 3 6.
Relief Valve Steam Discharge Thermal Mixing.
Schedule:
3rd Quarter 1976 Objeptive:
Develop techniques for predicting thermal mixing in the suppression pool during relief ~ valve discharge.
Description : Consolidate all plant and' test facility data available-on thermal mixing.
LOCA RELATED ACTIVITIES 1.
Mark' I Submergence Pool Swell Test in 4T Facility Schedule:
1st Quarter 1976 Objective:
Obtain pool swell data (i.e., surface velocity, break-through elevation, etc.) with a closed full scale single vent containment configuration and vent submergence typical of Mark I, downcomer lateral loads, and establish pool swell and jet impingement characteristics.
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Description:==
Modify'4T Facility to simulate Mark I downcomer submergence.
Instrument appropriately cnd perform tests.
2.
Determine Vent lateral Loads Schedule:
3rd Quarter 1976 - final Objective:
Refine main vent lateral load values to be expected during a LOCA event.
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Description:==
Utilizing data obtained in Item 1 above and data available from GE licensee test programs, to establish load values for all subsequent analyses.
3.
Establish LOCA Load Definition Basis Schedule:
2nd Quarter 1976 l
Objective:
Establish the basis for LOCA loads on a'll containment s tructures.
Descrip tions : Compare all appropriate available LOCA related test facility data.
Establish and verify analytical and experimental basis used to define loads on all other containment structures.
Document for future use.
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' Mark.I Containment. Evaluation -
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Long Term Program Page 4
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Define Final LOCA Design Loads
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Schedule:
3rd Quarter 1976 Objective:
Establish final design loads using basis developed in Item 3 above for the analyses to be performed on reference ' plants,
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Description:==
Before the final structural analysis is performed, define all loads ensuring that adequate attention has been given to 'all new and applicable' test and analytical data. This
.will include moropriate seismic loads.
5..
Perform Stress Analysis of Torus, Torus Internals, and Supports and Develop Structural Modifications if needed.
Schedule:
4th Quarter 1976 and 1st Quarter 1977 Objective:
Complete the analysis required to demonstrate torus 1
structure integrity during LOCA.
Develop generic con --
ceptual design fixes as necessary to make the design conform to the agreed-upon acceptance criteria.
These fixes would be tailored to specific plant application during implementation.
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Description:==
Utilizing the LOCA dynamic loads from the tests and analytical programs, perfonn detailed structural analysis of the representative plants. Evaluate results.in accordance with established acceptance criteria and develop generic design modifications as appropriate.
COMMON (LOCA AND RELIEF VALVE) ACTIVITIES 1.
Establish Criteria for Determining Adequacy of Structural Design Schedule:
2nd Quarter 1976 j
Objective:
Develop acceptance criteria to be utilized as the design basis for evaluating the' adequacy of the Mark I containments.
Description : Work with ASME Code Comittees and NRC representatives to
. arrive at a mutually agreeable basis for evaluating structural capability for all Mark I containments.
Document for future use.
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- 2. - Conduct Hardware Tests for Potential Structural Fixes it Required.
Schedule:
4th Quarter 1975 - 1st Quarter 1977 Objective:
Determine the load capability of existing critical structures or potential fixes for critical structural elements as identified in the test and analytical programs.
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Description:==
As critical structural elements are identified by the various programs, establish a parallel effort to develop acceptable modification.
It may be necessary to mockup and test existing structures or the proposed fixes to determine ultimate capability. Mockups would be tested to destruction.
3.
Compare to Plant Licensing Basis Schedule:
2nd Quarter 1977 Objective:
Establish and justify to the NRC the design adequacies of the torus including fixes,-if required, considering j
all of the applied loads.
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Description:==
Utilizing all load and strain information produced by the above programs, complete a detailed analysis of the repre-sentative plants-to evaluate the adequacy of all Mark I containments utilizing the agreed-upon acceptance criteria.
The completion of the Long Term Program is scheduled for mid-1977. We believe that this program is responsive to NRC requests.
Detailed planning and pro-curement of lead equipment has already started in order to meet the expected reporting date.
It is recognized that the program duration is longer than originally discussed with you. This is a direct result of the increased definition of the Long Term Program now available and the extended scope of the Short Term Program as documented in our submittals on that subject.
No other program duration extensions are known or anticipated. The ad hoc BWR Mark 1 Containment Owners will. continue to evaluate its progress in order to take advantage of any schedule improvements which can be made.
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