ML20032B378
| ML20032B378 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 11/02/1981 |
| From: | Johnson G NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| To: | CALIFORNIA, STATE OF |
| Shared Package | |
| ML20032B379 | List: |
| References | |
| ISSUANCES-OL, NUDOCS 8111050487 | |
| Download: ML20032B378 (26) | |
Text
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UNITED STATES OF AMERIrA yq s
NUCLEAR REGULATORY COMMISSION
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BEFORE THE ATOMIC SAFETY AND LICENSING BOARD NOVO 41984 r In the Matter of
' G2eca PACIFIC GAS AND ELECTRIC COMPANY
)
Docket Nos. 50-275 0.L. o>
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50-323 0.L.
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(Diablo Canyon Nuclear Power Plant, Units 1 and 2)
)
HRC STAFF'S RESPONSE TO GOVERNOR EDMUND G. BROWN JR.'S SECOND SET OF INTERROGATORIES INTERROGATORY I In the Staff Response, it is stated that the purpose of the Staff's December 16, 1980 letter to PG&E was 4 ensure that the Applicant's emergency i
plan had adequately taken into consideration the c%plications from an earth-quake which are discussed in that letter.
A.
Is it the Staff position that Revision 3 of the PG&E Emergency Response Plan adequately takes into consideration the items discussed in the December 16, 1980 letter?
B.
What criteria has the Staff used to determine whether the Applicant's Emergency Response Plan or any other documents or materials of Applicant adequately take into consideration the items discussed in the December 16 letter?
C.
If it is the Staff position that Revision 3 to PG&E's Emergency Response, Plan constitutas an adequate response to the NRC Staff's letter of December 16, 1980, provide the bases for that position, including citations to those portions of the plan which the Staff relies upon as DESIGNATED ORICIIIAL Cortified By T7)b
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. providing adequately for the complicating effects of an earthquake.
Describe all documents which form a basis for or relate in any way to your answer to this Interrogatory 1.
D.
At page 12 of the Staff Response, the Staff states that it "is satisfied that PG&E has adequately addressed the complicating effects that an earthquake may pose in the event the Emergency Plan has to be implemented in response to a radiological emergency."
(1) Wnat is the basis for the foregoing statement?
(2) What analyses has the Staff performed or is the Staff performing to reach the foregoing conclusion?
(3) What criteria is the Staff utilizing to reach its conclusion?
RESP 014SE A.
The Staff position is that Revision 3 of the PG&E Emergency Response Plan, when taken together with the three-volume study and plan, " Earthquake Emergency Planning at Diablo Canyon" dated September 2,1981, by the TERA Corporation, adequately takes into consideration the items in the December 16, 1980 letter.
B.
The criteria are the basic planning standards in the emergency planning regulation (10 CFR s 50.47(b)).
C.
The bases for the Staff position are that the documents referred to in Response 1.A., above, adequately address availability of resources and
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personnel to augment onsite staff, transit to and among emergency response facilities and communications with offsite organizations.
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_ The pertinent portions of the documents are in Appendix E of the Emergency Plan and Volume 1 of Earthquake Emergency Planning at Diablo Canyon.
D (1). See Response 1.C., above.
(2). See Response 1.C., above.-
(3). See Response 1.C., above.
INTERR0GATORY 2 At pages 2 and 3 of the Staff Response, it is indicated that Mr. John Sears spoke with PG&E and TERA Corporation employees on May 19, 1981 and September 11, 1981. For each discussion, what was discussed and who initiated these conversations? Did Mr. Sears nake any notes of or in any way keep any record of these discussions? If so, describe these notes or other documents.
RESPONSE
Mr. Sears initiated the discussion on May 19. The schedule for sub-nittal of the Applicant's analysis of earthquake effects was discussed.
The September 19 discussion wac initiated by Mr. Davis who discussed in general the content of the TERA documents.
No notes on either discussion were kept.
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_4-INT.1RROGATORY 3 Describe all analyses, reviews and other documents of the NRC Staff which relate in any way to tne TERA Corporation analyses subraitted by PG&E l
in early September 1981.
RESPONSE
The TERA documents have been reviewed by Mr. Sears and there are no written analyses.
INTERR0GATORY 4 In the TERA Report prepared for PG&E, the contractor assumes a maximun acceleration at the plant of slightly under 0.5. This is significantly 9
less than the 0.75g peak free field acceleration assumed for the SSE in the Diablo Canyon seissaic proceeding.
A.
Does the Staff believe that accelerations up to the 0.75g postulated for the M 7.5 SSE should be assumed by PG&E in analyzing the complicating effects of an earthquake? Provide the basis for your response.
B.
Does the Staff agree with the TERA selection of under 0.59 as the maximum acceleration to be postulated for the " severe" earthquake i
mentioned in the Staff's December 16, 1980 letter to PG&E7 Provide the basis 'for your response.
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. RESPONSE A.
The Staff does not believe that accelerations up to 0.759 postulated for the M 7.5 SSE need be assumed by PG&E in analyzing the complicating effects of an earthquake. The bases for this are: (1) the 0.75g peak acceler-ation assumed in tt 2 Diablo Canyon seismic proceeding was the basis for the design of reactor systems and components for seismic qualification, and not for emergency planning; and (2) since it is the availability of resources dnd facilities to deal with a spectrum of possible damage in the event of a severe. earthquake which was to be addressed, the capability of such resources and facilities to function can be evaluated based upon the peak accelerations postulated by TERA.
B.
The Staff agrees that the Applicant's analyses of severe earthquake effects on transportetton and comnunications' facilities adequately responds to the Staff's concern. The basis for this is that the earthquake postu-lated by TERA is severe enough to require assessment of and planning for the key commuri ;ation and transportation networks which may be affected by a severe earthquake in the vicinity of the Diablo Canyon Nuclear Power Plant.
l INTERR0GATORY 5 At page 4 of the Staff Response, the NRC Staff states that PG&E's Evacu-ation Time Assessment for Diablo Canyon Nuclear Power Plant is " satisfactory."
A.'What Staff analyses have been performed by or for the Staff regarding this evacuation time assessment and what is the basis for the Staff's positia,n that this Applicant response is satisfactory?
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. B.
Describe all documents which relate in any way to the PG&E
~ assessment.
RESPONSE
A.
The basis for the Staff statement that the Applicant's response is satisfactory is that the response st.tisfies the criteria of NUREG-0654, FEMA REP-1, Rev.1, Criteria for Preparadon and Evaluation of Radiological Emer-gency Response Plans and Preparedness in Support of Nuclear Power Plants, specifically, Section 11.J. and Appendix 4.
The analysis was performed by a cnntractor - the Texas Transportation Institute of the Texas A&M University System.
B.
The document is an October 28, 1981, letter report from Thomas Urbanik II, of the Texas Transportation Institute, to Mitzi Solberg, of the NRC Staff which rates the PG&E submittal excellent in every respect.
INTertROGATORY 6 At page 4 of the Staff response, the Staff states its position that the i
i system for notifying in Montana de Oro State Park is satisfaatory-A.
What analyses have been performed of this system for notifying persons in that State Park?
l B.
What is the basis for the Staff's position?
If the sole basis for the. Staff's position is Section 7.2-2 of the PG&E Emergency Plan, please so state.
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. RESPONSE A.
The Staff reviewed the description and the drawings in tne Emergency Plan of the warning system and discussed the warning system with the supplNr.
and also discussed notification with the Montana de Oro State Park Ranger and the San Luis Obispo County Sheriff. The system for ratification is also being reviewed by FEMA.
B.
The bases for the Staff position are included in the answer to 6(A).
1 INTERR0GATORY 7 At page 5 of the Staff Response, the Staff states that it believes that the location of PG&E's real time monitors is satisfactory.
A.
What is the basis for this Staff position and what analyses have been performed by or for the Staff? Describe all documents which relate in any way to the location of the reactor time monitors.
B.
Has the Staff considered requiring more real time monitors outside of the plant boundaries, but inside the 6-mile low population zone? Explain the rationale for your response.
RESPONSE
A.
The location of the real time monitors is indicated on Figure 7.3-4 of the Emerger>cy Plan, and the use of the monitors is described in Section 7.3.2.2 and 7.3.1.9 of the Emergency Pian. The Staff's review of this infor-mation formed the bas,is for the Staff's judgment.
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. Offsite real time monitors are not required by the NRC Staff, under regulations and guidelines.
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..c INTERR0GATORY 8 At page 5 of the Staff Response, the Staff states that it believes tne alternate evacuation route to the North through the Field Ranch is satis-factory.
A.
What is the basis for this position?
B.
What analyses have been performed by or for the Staff to reach this position?
C.
What criteria were applied by the Staff in determining whether the alternative eva.uation route is satisfactory?
D.
Does the Staff contend that the northern evacuation route will be available for use in wet or rainy weather?
E.
Describe all documents which relate in any way to the northern evacuation route.
F.
Llentify all Staff personnel who hate traversed the entire northern evacuation route.
EdSPONSE A.
The Staff's reconnaissancr of the raute formed the basis for the Staff's judgdsnt.
B.&C.
The Staff's professioral judgment was the basis for declaria; the route satisfactdfy.
.9-D.
Tne Staff judges that if rainy weather has made the northern route inpassable by vehicle, able-bodied persons would be able to walk.
E.
Une document relating to this route is in Appe.1 dix 7 to the Emer-gency Plan, Revision 2.
F.
John Sears has traversed the entire northern route.
INTERROGATORY 9 At page 5 of the Staff Response, the 5 :aff states its position that "the provisions for commenications and transport are satisfactory."-
A.
What is the basis for this position?
B.
What analyses have been performed by or for the Staff to reach this position?
l RESPONSE-The bases for this position are that if land lines are unavailable i
A.
f for communication, radio is available; and if land routes are not navigable, transport to the plant is possible by helicopter.
l B.
The Staff has reviewed the applicant's submittal.
INTERROGATORY 10 i
At page-7 of the Staff Response, the Staff takes the position that the l
PGhE criteria for guiding PG&E employees regarding when to recommer.d evacu-ation versus sheltering are satisfactory.
I i_
. A.
What is the basis for this Staff position?
B.
What analyses have been performed by or for the Staff regarding this position?
C.
In the event of a M 7.5 earthquake on the Hosgri fault, does the Staff believe that sheltering will continue to be a viable protec-tive action throughout San Luis Obispo County? Explain the basis for your position.
RESPONSE
A.
The Staff has reviewed the Applicant's implementing procedures for recommending shelter or evacuation and judges that these procedures comply with the guidance in NUREG-0654, Appendix 1.
B.
The Staff compared the Applicant's submittal with the guidance in NUREG-06S4.
C.
In the event of 3 7.5 Earthquake on the Hosgri fault, the reactor could be shut down safely.
In the event of release of any radioactivity, the licensee would rely on information from offsite authorities as to whether shelter would be a viable protective action.
l INTERROGATORY 11 At page 7 of the Staff Response, the Staff makes the following statement:
- The HRC Staff position is that the public information l
program is satisfactory, the Staff will revies, with FEMA, a draft of t.ie public information material ana that distri-bution of the material will be made prior to issuance of a full powed license.
. ~
.'o 0 A.
What is the basis for the Staff position that the public infor-mation program is satisfactory?
B.
What Staff review was made of the public information program prior to providing the above quotation in the Staff Response?
C.
What documents were reviewed or available to the Staff prior to making the above quoted statement in the Staff Response?
RESPONSE
A.
The basis for the staff position is Staff review of the description of the program in the Emergency Plan and review of the draft material.
B.
The Staff review of 11.A. was performed prior to providing the quo-tation in tae Interrogatory.
C.
Drafts of all of the documents to be used in the program were reviewed prior to making the above-quoted statement.
INTERROGATORY 12 Attached to the Staff Response was a May 18, 1981 Memorandum from Mr. William J. Dircks to J. C. Mark, Chairman of the Advisory Cor.inittee on Reactor Safeguards. At page 2 of that Memorandum, the following statement is made:
We have concluded that additional requirements, such as the design of additional facilities, structures, and systems to specifically withstand earthquakes are not necessary.
In parti-cular, no special seismic design of public notification systems, environmental monitoring capabilities or communications equip-ment is contemplated.
A seismic event coincident with a signi-ficant accident at the plant is a very low likelihood.
In addition, moderate seismic events would likely create a scenario
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e in which events slowly develop prior to the occurrence of a radioactive release. Sufficient time would be available for existing backup or alternate means of notification and monitoring to be effective.
(emphasis supplied).
A.
Provide all analyses and documents which provide the basis for or support the foregoing statement, including, in particular, those portions which are emphasized.
B.
Identify ali Staff members who worked on, contributed to, or otherwise participated in the foregoing statement.
C.
Provide any analyses or other documents which relate the fore-going statement to the site-specific condions and projected events at Diablo Canyon.
D.
Has the Staff calculated the likelihood, i.e., probability, of a significant accident at Diablo Canyon (or any other plant) coincident with a seismic event?
If so, describe and produce such calculations.
RESPONSE
A.
The documents are tne affidavits of Brian Grimes, NRC in the San l
Onofre Units 2&3 hearing before the Atomic Safety and Licensing Board dated June 22, 1981 and August 4,1981.
i B.
Brian Grimes and John Sears contributed to the foregoing statement.
C.
There are no other analyses or other documents which relate to the foregoing statement to the site-specific conditions and projected events at Diablo Canyon.
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i D.
No. The Staff has not calculated the likelihood, i.e., probability, I
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of a significant accident at Diablo Canyon (or any other plant) coincident with a seismic event.
IliTERROGATORY 13 In the Dircks Memorandum quoted in the preceding Interrogatory, reference is made to a March 16, 1981 ACRS Memorandum.
A.
Provide a copy of the March 16, 1981 ACRS Memorandum.
B.
Provide copies of all other correspondence and other documents by or between the ACRS and the Staff concerning emergency planning at nuclear facilities during and after natural events.
RESPONSE
A.
Attached is a copy of the March 16,1981 ACRS Memorandum.
B.
With regard to providing other correspondence and other documents by or between tne ACRS and the Staff concerning emergency planning at nuclear facilities during and after natural events, attached is a May 18, 1981 Memo from Dircks to Mark.
INTERROGATORY 14 At page 8 of the Staff Response, it is stated that the draft NRC inspec-tion report (presumably that for the August 19, 1981 exercise) was in the process of being finalized.
A.
Dercribe that inspection report and its conclusions.
B.
Produce that document for inspection and copying.
RESPONSE
A.aB. Attached is a copy of the inspection report.
INTERR0GATORY 15 At page 17 of the Staff Response, the Staff states that the UHF and VHF radio systems at Diablo Canyon "would be expected to be operational for the OBE and SSE."
A.
What is the basis for the foregoing Staff statement?
B.
What analyses have been prepared by or for the Staff to support tnis statement?
RESPNSE A.
The basis for the Sta'f statement is that if land lines were lost, radio which does not depend on land lines would be available.
B.
The Staff analysis consisted of a review of the TERA analysis of comunications.
INTERR0GATORY 16 l
At page 24 of the Staff Response, the Staff states tht the TSC, OSC, and interim EOF meet the " intent" of the guidance of NUREG-0696.
A.
By the foregoing response, does this mean that the Staff does i
not take the position that the foregoing facilities meet the reliability requirements of NUREG-06967 B.
What is meant by " intent"?
RESPONSE
A.
The reliability criteria of NUREG-0696 refer to the permanent emer-gency response facilities for which the full implementation date is October 1, 1982.
B.
Tne objectives of the emergency response facilities are described in HUREG-0696 and in the Staff judgment, the interim facilities for Diablo Canyon meet the intent of those objectives in that the functions called for can be performed in the facilities.
INTERROGATORY 17 At page 24 of the Staff Response, the Staff states that the EOF and UDAC may not remain fully functional during an earthquake. The Staff goes on to note, however, that the assessment and communications functions will be performed at the TSC or the control room.
A.
How would assessment and communications functions by and with the County be accomplished in the event that the EOF and UDAC were not available?
B.
Describe the analyses ai : other documents wnich document that assessment and communicc+ ions functions would still be accomplished in the event that these facilities were not available?
RESPONSE
A.&B.
If the EOF and UDAC were not available, assessment would continue to be done in the control room and TSC since these lucations are the source I
. i of all information transmitted to the EOF and UDAC. Communications by radio to county personnel would be available.
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INTERROGATORY 18 At page 24 of the Staff Response, the Staff takes the position that the interim EUF does not need to raeet the criteria of NUREG-0695 of being "well engineered for the design life of the plant."
A.
What is the basis for this Staff position?
B.
What analyses have been ps formed to ensure that the interim EOF is in fact adequate?
RESPONSE
A.
The criteria for interim Emergency Response Facilities are stated in NUREG-0694 which does not include the criterion of being "well engineered, for the design life of the plant.
B.
The Staff examined the interim EOF in visits before the exercise and during that exercise.
INTERROGATORY 19 At page 25 of the Staff Response, the Staff states that it is its position that the edergency procedures for Diablo Canyon are'a'dequate_to respond to an emergency.
A.
Describe all analyses which have been performed by or for the NRC Staff on the PG&E energency procedures.
t B.
What is the basis for the Staff's position?
RESPONSE
A.
The Emergency Planning Licensing Board has reviewed the procedures submitted by the applicant.
B.
It is the Staff's professional judgment that the procedures provide adequate and clear direction to the person (s) called up to implement them.
' Further audit of the emergency procedures will be performed by NRC Inspection
& Enforcement personnel during the final pre-operational inspection prior to full power operation.
INTERROGATORY 20 At page 5 of the Joint Intervenors' Response, the Staff indicates that th; Staff's final' conclusions on Diablo Canyon emergency preparedness would be set-forth in SER Supp. 15. They were not.
A.
Which SER Supplement will contain the Staff's final conclusions?
B.
When does the Staff intend to publish this Supplement?
RESP 0 HSE A.
Supplement 16 will contain the Staff's final conclusions.
B. 'The Staff intends to publish this Supplement after receipt of the
- FEMA evaluat'jon of State and local plans.
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s ljiTERR0GATORY 21 At page 7 of the Joint Intervenors' Response, the Staff states that it does comply with Section SC.47 of the NRC RegulaHons.
A.
What is the basis for this Staff position?
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B. ' What analyses or other documents provide the basis for this Staff position?
RESPONSE ~
The basis for the Staff statement on page 7 is that the onsite and A.
offsite emergency' response plans must satisfy 10 CFR 9 50.47 prior to full power _oppration.
Es. The documents which will provide the basis for the Staff position are the Applicant's Emergency Plan, reviewed by the 14RC Staff, and state and local plans, reviewed by FEMA.
INTERROGATORY 22
' At pages"12'and 13 of the Joint Intervenors' Response, the Stuff sets forth generally its position on how emergency plans should compensate for the potectially complicating effects of an earthquake. As pointed out by the Staff. cit is.possible that an earthquake might occur which does not caust or occur simultaneously with an accident and radiological release at D;ablo Colyoit, but rather does interfere with elements of emergency planning and preparedness, for example, c~n:nications systems and/or evacuation rogtes.
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A.
In the event an earthquake occurs which disrupts communications and/or evacuation and transportation facilities, does the Staff believe that the plant should be shut down until there is restoration of communi-cation and transportation facilities?
B.
Please explain the basis for your position and describe any documents relating thereto.
RESPONSE
A.&B.
The reactor plant would be shut down in the event of a severe earthquake. The decision to restart would be reviewed by the NRC Staff before restart.
INTERROGATORY 23 At page 12 of the Joint Intervenors' Response, the Staff states that an Applicant should assume "that the piant will experience earthquake effects of the type normally experienced in the geographical region where the plant is situated."
A.
Does the Staff believe that faults other than the Hosgri fault (for example, the Rinconada fault) should be examined since it is in the same geographical reg 1on where the plant is located?
B.
Provide the basig for the Staff's position.
- d., If the Staff does believe other faults should be analyzed, which are they and what accelerations does the Staff predict fro 3 SJch other faults?,
RESPONSE
A.
No.
B.
See Response 4A & B.
C.
Not applicable.
l INTERROGATORY 24 At page 23 of the Joint Intervenors' Response, the Staff states that a decision to order evacuation or sheltering will be made "before any release of radioactivity occurs...."
A.
What is tne basis for the foregoing statement?
B.
Describe all analyses or other documents which address this matter.
RESPONSE
A.
We are unable to find the referenced statement on page 23 of the Joint Intervenor's Response. The basis for the concept that the Applicant's staff would recommend protective actions before any release of radioactivity -
occurs lies in the applicant's complitnce with Appendix 1 of NUREG-0654 which directs the operation of a nuclear plant to assess and declare the emergency upon the basis of measureable and observable indications in the control room, not en the basis of offsite monitoring of an effluent release.
B.
NURED-0654 and the PGE Emergency Implementing Procedures.
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INTERROGATORY 25_
Does the Staff agree that the Diablo Canyon pressurizer heaters and related structures, instruments, systems and power sources are properly classified as non-safety grade? Provide the basis for your position and describe all documents whiO, relate in any way to the classification question.
RESPONSE
Operation of the pressurizer heaters at Diablo Canyon is not a critical safety function and therefore the heaters are not required to be designed to safety grade criteria. The heaters are located within the pressurizer which is designed to safety grade criteria in accordance with its function as part of the reactor system pressure boundary. The heaters have the capability of being connected to safety grade power sources as discussed in Sec. tion II.E.3.1 of Supplement 14 to the NRC SER for Diablo Canyon.
The critical safety functions which must be provided by safety grade systems are identified in Section III.C of Appendix A to 10 CFR 100. The pressurizer heaters are not required to provide any of these critical safety functions. Operation of the pressurizer heaters is not required to mitigate any of the design basis events described in Chapter 15 of the Diabic Canyon FSAR. Although opt. ration of the pressurizer heaters is required to maintain primary system pressure for power operation and hot standby, operation of the pressuri5er heaters is not required to bring the plant to cold shutdown, which is a safe and stable condition. Tests at the Sequoyah Nuclear Power Plaat have demonstrf ted that the effect of deenergizing the pressurizer
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neaters would be gradual depressurization of the primary system (100 psig/ hour) with no loss of natural circulation. These tests are described in a letter from L. Mills TVA, to A. Schwencer, NRC, transmitting the Sequoyah Nuclear Plant Unit I special startup test report dated July 29, 1981, attached hereto.
Failure of the pressurizer heaters to operate would allow the reactor system to gradually depressurize which, in the absence of any corrective operator action, would eventually cause automatic actuation of the ECCS.
Tne capability to provide emergency power to the pressurizer heaters is available at Diablo Canyon to reduce the number of demands for ECCS to operate in accordance with Item II.E.3.1 of NUREG-0737 and Item 2.1.1 of NUREG-0578.
INTEF R0GATORY 26 Does the Staff believe that the pressurizer heaters and related struc-tures, instruments, systers and power sources should be seismically and environmentally qualified? Provide tne basis for your response and a description of all documents relating to the qualification question.
RESPONSE
The pressurizer heaters are qualified to operate within the normal environment,of the pressurizer.
Neither the pressurizer heaters, related structures, ihstruments, systems and power sources are required to withstand earthquakes or environmental conditions resulting from postulated accidents I
)
. with the exception of the pressurizer vessel which houses the heaters and the backup emergency power saurces as disc,, sed in the response to Interrog-atory 25 for the reasons described therein.
INTERROGATORY 27 The power operated relief valves and block valves at Diablo Canyor, are not classified as safety grade. Does the Staff agree that these items (as well as related structures, controls, instruments and power sources) need not be classified as safety grade? What analyses, it any, have been con-ducted to support such classification as non-safety grade? Describe all such analyses and all other documents relating to the question of the classification of block and relief valves.
RESPONSE
Proper operation of the PORVs and the associated block valves is not a criticial safety function and therefore the PORVs and block valves are not required to be designed to safety grade criteria. The pressurizer, PORVs and block valves are designed to safety grade criteria with respect to their function as part of the reactor system pressure boundary.
Power to two of the three PORVs and block valves is supplied from safety grade power sources as discussed in Section II.G.1 of Supplement 10 to the NRC SER for Diablo Canyon.
The critical safety functions which must be provided by safety grade systems are identified in Section III.C of Appendix A to 10 CFR 100. The I
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PORVs and block valves at Diablo Canyon are not required to provide any of these critical safety functions. The function of the PORV is to prevent unnecessary opening of the pressurizer safety valves and to provide a backup neans of depressurization and overpressure protection. The function of the block valves is to permit isolation of a leaking or failed open PORV.
Proper operation of the PORVs and block valves is not required to mitigate the consequences of any design basis accident. Analyses of design basis accidents are contained in Chapter 15 of the FSAR.
Failure of a PORV and block valve to function can cause the equivalent of a small-break LOCA, but if the failure occurred in conjunction with a LOCA, the consequences would not be signifi-cantly altered. An unisolated stuck-open PORV would not result in core damage as deraonstrated by analyses contained in Chapter 15 of the FSAR and in WCAP-9600.
Analyses of open PORVs in conjunction with a loss of coolant accident are also contained in WCAP-9600. These analyses demonstrate that opening the PORVs improved core cooling.
Emergency power has been provided to two of the three PORVs and to the three block valves to reduce the number of challenges to safety valves and ECCS during operation in accordance with Item II.G.1 of NUREG-0737 and Item 2.1.1 of NUREG-0578.
Respectfully submitted.
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L" George. Johnson Counsel for NRC Staff Dated at Bethesda, iaryland this 2nd day of November,1981
UNITED STA.ES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ' ATOMIC SAFETY AND LICENSING BOARD In the Matter of
)
)
PACIFIC GAS AND ELECTRIC COMPANY
)
Docket Nos. 50-275 0.L.
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50-323 0.L.
(Diablo Canyon Nuclear Power Plant
)
Unit Nos.1 and 2)
)
AFFIDAVIT OF JOHN R. SEARS I, John R. Sears, being duly sworn, state as follows:
1.
I am employed by the U.S. Nuclear Regulatory Commission as a Senior Reactor Safety Engineer, Emergency Preparedness, Office of Inspection and Enforcement.
2.
I am duly authorized to participate in answering Interrogatories 1 through 24 and I hereby certify that the answers given are true to the best of my knowlege.
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Jop; R. Sears Subscribed and sworn to before me this Q'd day of October,1981.
.hL,1~) dd-37) SO7 Notary Public d
My Counission expires: O lou /, / Q,SQ J
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UNITED STATES 0. AMERICA NUCLEAR REGULATORY COMMISSION l
BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of
)
)
PACIFIC GAS AND ELECTRIC COMPANY
)
Docket Nos. 50-275 0.L.
I
)
50-323 0.L.
(Diablo Canyon Nuclear Power Plant,
)
Unit Nos. I and 2)
)
AFFIDAVIT OF WALTON L. JENSEN I, Walton L. Jensen, being duly sworn, state as follows:
1.
I am employed by the U.S. Nuclear Regulatory Commission as a Senior Nuclear Engineer, Reactor Systems Branch, Division of Systems Integration, Office of Nuclear Reactor Regulation.
2.
I am duly authorized to participate in answering Interrogatories 25-27 and I hereby certify that the answers given are true to the best of my knowledge.
f Walton L. Jensen f
Subscribed and sworn to before me thu,? 7 *'ty of October,1981.
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liy Commis.sion expires: b l, f M [ M
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UNITED STATES
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y NUCLEAR REGULATORY COMMISSION 3,q
.r ADVISORY COMMITTEE ON REACTOR SAFEGUARDS l
- e JH W ASH mGT ON, D. C. 20555 March 16,1981 MC40RANDUM FOR:
W. J. Dircks Executi e
'ector for Operations FROM:
J. C.. ark, Clba
SUBJECT:
EMERGENCY PLANNING AT NUCLEAR FACILITIES DURING AND FOLLOWING NATURAL EVENTS In its review of nuciaar power plants, particularly those in highly seismic areas, the ACRS has raised several questions regarding erer-gency planning and preparations, and the degree to which they take into account natural events such as carthquakes. For example, will systems and features used to alert the. public to an accident in the plant, the equipment to monitor enviror. mental conditions, the com-munications network, and emergency evacuation routes be available during or following a major earthquake.
The Coumittee recomends that the.NRC Staff give further. considera-tion to the development of emergency plans and the operability of equipment needed to deal with nuclear emergencies which result from natural disturbances.
In this connection, the Comittee suggests that in the planning of exercises for the NRC Emergency Operations Center, consideration should be given to postulated scenarios including natural catastro-phies such as earthquakes and related plant failures, particularly the failure of equipment or systems that ari not Seismic Class I and the impact of such failures on systems important to safety.
It would seem advisable also that the FEMA be requested to review the capabilities of local emergency and disaster organizations to cope with multiple emergencias such as might result from a major earthquake followed closely by an accident at a nuclear power plant.
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Comissioners
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S. Chilk, SECY H. Denton, NRR J
V. Stello, I&E j
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' TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 37401 400 Chestnut Street Tower 11 July 29, 1980 Director of Nuclear Reactor Regulation Attention:
Mr. A. Schwencer, Chief Light Water Reactors Branch No. 2 Division of Licensing U.S. Nuclear Regulatory Con. mission Washington, DC 20555
Dear Mr. Schwencer:
In the Matter of the Application of
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Docket No. 50-327 Tennessee Valley Authority
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Enclosed for your review are five (5) copies of the Sequoyah Nuclear Plant Unit 1 Special Startup Test Report dated July 28, 1980.
If you have any questions, please get in touch with D. L. Lambert at FTS 857-2581.
Very truly yours, TENNESSEE VALLEY AUTHORITY
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4/JJ L. M. Mills, Man'ager
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Nuclear Regulation and Safety Enclosure (5) mB* **
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3.0 (Continued) 3.3 Test #3, Natural Circulation with Loss of Pressurizer Heaters 3.3.1 Ctjectives l
(a) To verify the ability to maintain natural circu-lation and saturation margin with the loss of the pressurizer heaters while under natural circulation conditions.
I (b) To determine the RCS depressurization rate after natural circulation is established and the pressurizer heaters are tripped.
(c) To verify the margin to saturation can be con-trolled 'through the use of primary charging flow and secondary steam flow.
(d) To provide operator training in the natural circulation mode with the further degraded condition of the 1 css of all pressurizer heaters.
3.3.2 Results With the reactor at approximately 3% power the reactor coolant pumps and all pressurizer heaters were tripped ano the reactor coolant system allowed to come to equilibrium conditions.
The reactor coolant system charging and letdown flow rates were adjusted to main-tain a constant pressurizer level and the p essurizer was allowed to slowly cool.
Over the testing period the cooldown rate averaged between 6 and 7*F/hr. -(ap-proximately 100 psig/hr.).
1 I
Once the depressurization rate ha5 been determined, primary system charging was increased to verify the margin to saturation could be controlled by increasing pressurizer level (and therefore system pressure).
The resporse to a 40 gpm increase in charging flow was immediately noticeable In system pressure and satura-tion margin. The pressure increase averaged around 12 to 14 psig per percent increase in pressurizer level.
A slight increase in steam flow slowed the pressure increase due to cooling of the primary system but the saturation margin continued to increase.
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