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MAR 0 61986
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C; \ [,U 'l MEMORANDUM FOR: Patricia G. Norry, Director Office of Administration FROM: Victor Stelloo, Jr.
Acting Executive Director for Operations
SUBJECT:
DELEGATION OF AUTHORITY Appendix 4130-C, Part VI.C.1.c authorizes the EDO to approve grade and pay retention for individuals who are otherwise eligible and who move voluntarily to lower graded positions during a reorganization or reclassification announced by NRC management in writing.
I hereby delegate the above stated authority to the Director, Office of Administration.
The authority may not be redelegated.
Original signed by, Victor Stelle .
Victor Stello, Jr.
Acting Executive Director for Operations DISTRIBUTION O&P r/f P&PD r/f P&PD s/f VStello JRoe 8607140383 860702 PDR FOIA TRehm GARDE 86-BO PDR JSniezek EDO f/r Re. typed;
- see previous concurrence.
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DATE : : : : : :03/ /86 :03/ 9 /86 0FFICIAL RECORD COPY
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MAR 0 61996 MEMORANDUlf FOR: Chairman Palladino FROM: Victor Stello, Jr.
Acting Executive Director for Operations i
SUBJECT:
MEETING WITH THE BELGIAN REPRESENTATIVES REGARDING THE DESIGN PHILOSOPHY OF DOEL 3 AND 4 Representatives from the Belgian Safety Review and Inspection Organization, Vincotte, and the Belgian Architect Engineer for Doel Units 3 and 4, recently briefed the NRR staff on the safety features and experience of these plants. The NRC regulations provided the foundation for the design requirements imposed on these Belgian units. However, additional design criteria were imposed due to local conditions and policy.
Knowledge of the design and construction of these facilities provides valuable insights for application in our related activities, such as the resolution of USI A-45, Backfitting, and Safety Goal Policy Development.
Therefore, I am forwarding NRR's meeting sumary for your information.
Original signed by Victor Stello Victor Stello, Jr.
Acting Executive Director for Operations
Enclosure:
Meeting Sumary DISTRIBUTION l Central File l cc: Comissioner Roberts NRC PDR Comissioner Asselstine EDO Reading Comissioner Bernthal TAMB Reading Comissioner Zech PPAS )
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Enclosure MEETING WITH BELGIAN REPRESENTATIVES i
REGARDING THE DESIGN PHILOSOPHY OF DOEL 3 & 4
SUMMARY
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l On February 11,1986, NRR met with representatives from Vincotte, the Belgian I
Safety Review and Inspection Organization, and Tractionel, the Architect Engineer, to discuss the design and operating experience of the Doel 3 & 4.
This report, which provides a sununary of that meeting, is provided to you for your infonnation.
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The latest Doel units (Nos. 3 and 4) are of particular interest to the staff l since they are " bunkered" designs that provide a fairly full featured "second
! level" of protection against most external events. The Belgians are backfitting i
4 the earlier Doel 1 & 2 units to provide additional protection. Knowledge
( of the design, construction and operation of these facilities provides j
valuable insights for application in our related activities such as the resolution of USI A-45, Shutdown Decay Heat Removal, Safety Goal Policy development, and backfitting. .
i The Doel site is Belgium is densely populated and highly industrialized. In light of the
- I located approximately 9 miles northwest of Antwerp, Belgium. <
population in the vicinity and due to the proximity of major petrochemical Il - facilities, a shipping channel, and the history of military aircraft crash ;
incidents throughout Europe, the design basis of the plants included protection j against specific external events including gas cloud explosion, large-scale fire, direct hit aircraft crashes, acts of malviolence, and other accidentsDo making the control room inaccessible. The MWe) design while Doel 4 is primarily of Westinghouse (1000 MWe) design.
features incorporated into the design to acconsnodate these events include a 4
crash / explosive resistant secondary containment and a bunker that houses three independent physically separated 50% trains of emergency feedwater j,
(EFW), reactor coolant make-up and boration, and two 100% trains of reactor l coolant pump seal injection. Each of the three redundant trains are The bunker l[ independent and self sufficient from water supply to injection.
r *r protects all of the support systems, including electrical power and cooling systems for these functions and provides protection for portions of otherWith a essential systems such as the main steam system.
3 4
control room, the bunker systems are designed to automatically bring the plant to hot shutdown and maintain that condition for up to three hoursIt should als following activation without any operator action.
j that without the bunker, Doel 3 & 4 have a higher degree of redundancy and separation than their U.S. counterparts. First level systems include three 100% trains of AFWS, RHR, and HPSI.
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l The decision has also been made to backfit Doel 1 & 2 with an additional single train of equipment, including EFW and other functions, that would be manually controlled and not meet single failure criteria.
Some of the key points to note are the following:
o The Doel 3 & 4 design evolved solely from a government mandated licensing basis that included protection against certain external events. The method to meet the design basis, was left primarily to the utility and the Architect Engineer.
i o The Belgians did use a " Safety Objective" for plant design. However the i safety analysis is based on deteministic principles. The general safety objective was that the risk to the public from all reactor accidents would be much less than other risks of life. Since construction began in 1975, other more detailed criteria were based on WASH-1270.
They view the usefulness of PRA as we do - as a tool to provide insights into the plant safety, o The decision to add the bunker rather than redesign or re-site the plant appears to have resulted from the limitations of the time,The e.g., site bnkered availability, schedule for installation / construction etc.
system of these units was designed primarily to protect against certain events and not to improve the overall mitigation of accidents.- However, during the last few years, the margin afforded by this extra safety l
equipment has facilitated their resolution of several safety issues such
] as Station Blackout, i.e., an extra dedicated diesel for each of the i
three trains is bunkered for each unit.
l o Decisions, early on, concerning the plant design basis resulted in cost effectiveconstruction(thebunkerwasestimatedtocostabout8%ofthe total plant cost), resolved initial licensing concerns, and were again highly cost effective when utilized to resolve new safety concerns that emerged throughout the years of construction and operation.
o The Doel bunkers are not intended to provide additional protection
! against internal events such as steam generator tube ruptures or loss of coolant accidents. This bunker concept relies on the retention of l
i primary coolant system serviceability.
o The Doel 3 & 4 plant availability has not been degraded by adding the additional bunker equipment. The reliability of the bunkered systems is good and there have been no significant spurious actuation problems.
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o The government authorization to operate all Belgian plants includes a requirement for a 10-year periodic reevaluation of the plant to the most recent rules and practices in the U.S. and the European community. This reevaluation provided the engineering basis for backfit of Doel 1 & 2.
Important improvements, such as TMI improvements were implemented immediately and were not delayed to the 10 year interval, however the 10 year review provides for a coordinated and more comprehensive evaluation.
o The backfit of Doel 1 & 2 was based on engineering judgement to remedy problems that were identified from (a) a comparison of the facilities I with the current licensing (requirements, and (b) operating experien reviews of Doel 1 & 2 and >
othercountries(includingTMI). The addition of dedicated systems seems to be the preferred approach to improve older European plants to remedy problems on separation, physical protection, and shared support systems, o The potential exists for another Belgian unit to be ordered, in the late l 1980s, and constructed at the Doel site. Our impression from the l meeting is that the design of such a new unit would not be identical to Doel 3 & 4. Therefore, the latest existing bunkered design is not contemplated as a standard design in Belgium.
The staff has been following the various design alternatives of other countries to accommodate different protection objectives. Lessons have been learned from our brief review of Sizewell and current review of Paluel. Regarding the general utilization of bunkered systems, it appears that these designs accommodate local criteria but are not developed to the point where a standard international design is emerging. This vlew is useful regarding our thoughts for standard plants. The economic and social feasibility of the nuclear plant produced the non-standard design of Doel 3 & 4, and it is obvious that the plant site can impact final plant design.
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. The Honorable John J. Duncan In sumary, the NRC is concerned about the problems affecting TVA, and how they affect the people which the utility serves. We are doing evirything possible within the statutory regulations to ensure that TVA resolves issues raised on their facilities in an expeditious manner without endangering the health and safety of the public.
I trust this will assist you in responding to your constituent about his Concerns.
Sincerely.
Original signed h Victor Stello a.
Victor Stello, Jr.
Acting Executive Director for Operations SEE PREVIOUS CONCURRENCES m ,
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UNITED STATES E -
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( ;$ WASHINGTON, D. C. 20555 9 F 4, * . . . + ,J FEB 2 01986 The Honorable John J. Duncan -
U. S. House of Representatives Washington, D. C. 20515
Dear Congressman Duncan:
This letter is in response to your January 20, 1986, letter regarding concerns of a constituent from the law offices of Swafford and Mitchell who expressed the concern that the NRC was dilatory in advising TVA what needs to be done to correct TVA's problems with their nuclear program. The letter further stated that "the NRC should tell TVA what to do, and then see that it is done, other-wise, the NRC should not be in charge of nuclear plants."
- The newspaper article attached to the January 6,1986, letter contained a good explanation of the staff's position in this and all NRC interactions with 'the utilities who build and operate nuclear power plants.
The NRC is responsible under the Atomic Energy Act of 1954, as amended, to assure that licensed nuclear power plants provide adequate protection of the public health and safety. I can assure you that the Commission is cenducting its investigations of TVA actions to correct their corporate as well as plant-specific problems in an expedited manner and in accordance with applicable laws, NRC regulations, and the Commission's policy statement.
The constituent's letter suggests the NRC should actively participate with TVA in developing and implementing the solution to their problems. The staff, cannot dictate solutions to TVA. The responsibility rests with TVA to deter-mine those. solutions. However, we do indicate, to the best of our ability, any of our concerns with TVA responses to resolve issues in as much detail as possible. As part of the NRC review of TVA's actions to resolve their problems, the NRC will inspect and review selected aspects of the TVA facil-ities' design, construction, and oparation. Results of these inspections and reviews will be documented in safety evaluation reports and inspection reports that are available at the Chattanooga Hamilton County Library, Chattanooga, Tennessee.
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O MAR 111996 MEMORANDUM FOR: Chairman Palladino FROM: Victor Stello, Jr.
Acting Executive Director for Operations
SUBJECT:
DESIGN ADEQUACY OF THE AUXILIARY PRESSURIZER SPRAY SYSTEM AT PALO VERDE NUCLEAR GENERATING STATION In a letter to you dated January 13, 1986, Messrs. Jesse C. Ebersole and Glenn A. Reed noted that the ACRS had decided during its November 1985 meeting not to provide additional comments regarding the design adequacy of the auxiliary pressurizer spray system at the Palo Verde Nuclear Generating Station. Messrs. Ebersole and Reed expressed disagreement with that decision and provided their comments in their letter to you.
In view of the pending Commission consideration of the full power license for Palo Verde Unit 2, I am forwarding for your information the enclosed staff discussion of the concerns expressed by Messrs. Ebersole and Reed.
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Original signed by Victor Ste11of Victor Stella, Jr.
Acting Executive Director for Operations
Enclosure:
As stated cc: Commissioner Roberts DISTRIBUTION GREEN TICKET 001338 Comissioner Asselstine Central File Commissioner Bernthal NRC PDR w/ incoming JRoe Comissioner Zech L PDR w/ incoming TRehm OPE EDO #001338 JSniezek OGC EDO Rdg File CHeltemes SECY HDenton/DEisenhut GCunningham DCrutchfield TSpeis OELD GKnighton CONTACT: VStello R. Wright, NRR PPAS (EDO #001138 w/ incoming) x28900 FMiraglia/ Mary Schaaf
- PREVIOUS CONCURRENCE SEE DATE
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i ENCLOSURE STAFF DISCUSSIONS OF CONCERNS EXPRESSED BY J. EBERSOLE AND G. REED
- 1. Staff Review of the Auxiliary Pressurizer Spray System (APSS)
As reported in SECY 85-384, the Arizona Nuclear Power Project (ANPP) has responded to the staff concerns regarding design adequacy of the APSS in letters dated October 15, 1985, October 22, 1985, and November 4,1985. The staff also
- addressed this issue in the ACRS Subcommittee meeting of November 5, 1985, and ACRS Full Comittee meeting of November 7,1985. l In NUREG-0857, Supplement No. 9, Safety Evaluation Report related to the operation of Palo Verde Nuclear Generating Station, dated December 1985, the
. staff reported the details of our evaluation on this subject. The staff's conclusion is that the current design of APSS and the pressurizer gas vent system's with the planned modifications and surveillances provide adequate means of reactor coolant system (RCS) depre5surization at an appropriate rate of
, depressurization to satisfy the requir,ed safety function at Palo Verde.
, - The bases of the staff conclusion are as follows:
- 1. Within the design basis, the appropriate rate of depressurization is
., based on two scenarios: a) steam generator tube rupture (SGTR) accident plant mitigation, cold shutdownand b) perreactor coolant the staff system position depressurization in the Standard Review during(BTP Plan RSB 5-1).
- 2. By a letter dated October 15, 1985 (ANPP-33713), ANPP provided the
- results of a reanalysis of the SGTR at..ident. In this reanalysis, the APSS was assumed inoperable and the safety-grade gas vent system from the pressurizer was used for accident mitigation. The reanalysis showed that the radiological consequences are within the limits of 10 CFR 100 guidelines. An independent staff evaluation verified the results of the ANPP reanalysis. The staff also reviewed the design of the gas vent system from the pressurizer and concluded that it meets safety-grade standards.
- 3. To satisfy BTP RSB 5-1, the APSS is needed to depressurize the RCS during plant cold shutdown. However, as indicated in BTP RSB 5-1, a plant which receives its operating license after January 1979 is classified as a Class 2 plant with respect to implementation requirements. Palo Verde Units 1, 2 and 3 are Class 2 plants and their design does not have to meet all the provisions specified in BTP RSB 5-1. Specifically, for a Class 2 plant, manual operator actions outside the control room are permitted to correct a single failure of a safety-related component if those actions can be justified.
During the staff review of the subject, ANPP comitted to implement a number of modifications to the Palo Verde design to improve the operator's ability to operate the charging / auxiliary spray system from
t the control room. ANPP also committed to Technical Specification :
. changes which would ensure the likelihood of APSS flow paths. In order i to reduce the probability of damage to the charging pumps with respect
- to possible gas binding, ANPP comitted to do the following
- a) perfom i an external surface examination on the Unit 2 charging pumps utilizing the appropriate NDE technique, b) perfom weekly visual examinations of each charging pump with appropriate aids suitable for the detection of cracking, c) declare the charging pump inoperable within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of i discovery of an apparent thru-wall crack, d) perfom a demonstration i of the hydrogen gas venting process at the charging pumps prior to
! initial criticality at Palo Verde Unit 2, and e) provide a detailed j evaluation of the charging pump operability when subjected to the
- various phenomena associated with hydrogen gas binding prior to the end of the first refueling outage of Palo Verde Unit 1. - .
Based on the enhancement of the APSS proposed by ANPP and other ANPP commitments discussed in NUREG-0857, Supplement 9, the staff concludes thaf reasonabTe assuranci exists that the APSS would perform its safety-related function for plant cold shutdown and that the design of ;
APSS meets the provisions in BTP RSB 5-1 applicable for Class 2 plants. l l
II. Test Data for the APSS and Pressurizer Vents I
On January 24, 1986, Palo Verde Unit 1 perfomed its boron mixing and natural circulation test to demonstrate its compliance to BTP RSB 5-1. The APSS was used for RCS depressurization after the RCS hot leg temperature reached 350*F !
and the RCS pressure was approximately 1500 psig. Several members of the NRR staff observed this test. The preliminary results show that with one charging pump in operation, the RCP seal injection system open, and the loop isolation valves (CH-239 and CH-240) slightly open, the rate of RCS depressurization is l approximately 13 psi per minute. Thus, the APSS has demonstrated that RCS depressurization is achieved during plant cold shutdown per the requirements ;
i of BTP RSB 5-1. l ANPP has stated that the flow paths of the gas vent system from the pressurizer !
, were tested as a part of Unit 1 pre-core hot functional tests in 1984. However, l the rate of RCS depressurization using pressurizer vents has not yet been determined by test. The need for testing the depressurization capability of the pressurizer gas vent estem is currently being discussed between the licensee and the staff to determine whether further action is warranted.
III. Concerns Expressed by J. Ebersole and G. Reed Messrs. Ebersole and Reed have expressed concerns regarding the lack of a rapid depressurization capability in the Palo Verde design. The lack of PORVs in current plants designed by Combustion Engineering was highlighted to the Comission at the Commission meeting held on July 28, 1982, to consider a full power license for San Onofre 2. At that meeting, the staff recommended that '
i i the Commission require these plants to install PORVs. However, the Commission
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l voted not to require PORVs and to await the completion of the staff generic study on this subject. The staff study was completed and sent to the Commission as SECY 84-134 on March 23, 1984. It was subsequently published as NUREG-1044,
" Evaluation of the Need for a Rapid Depressurization Capability for CE Plants." '
The conclusion of this study was that the cost-benefit analysis showed that ,
the need for PORVs was a "close call" (that is, the detriments to safety, or j
increased risk, tended to balance the improvements to safety, or decreased risk).
1 Furthermore, it was concluded that because the benefits of the PORV as a rapid depressurization feature were directly applicable to improving decay heat removal capability, it was appropriate to defer a decision on the neer' or PORVs to the 1 USI A-45 Program (Decay Heat Removal Requirements). The sta0 ~; currently following this approach.
In general, the staff agrees with Messrs. Ebersole and Reed that a rapid
. depressurization capability has substantial merit. Although it cannot be justified at this tjme for backfit in operating reactors or in reactors for which" construction is substantially complete, the staff believes such a system
- should be seriously considered on future plants.
On Monday, February 24, 1986, the staff met with Mr. Glen Reed of the ACRS and
) - Westinghouse representatives to discuss the merits of a rapid depressurization system. Mr. Reed expressed his views on the subject, and Westinghouse provided information on how such a system was being incorporated in their advanced design and, in Yact, existed in their operating plants.
The following are staff responses to the concerns of J. Ebersole and G. Reed J expressed to Chairman Palladino in their letter of January 13, 1986:
Concern ,
"We believe that these current systems at Palo Verde, even with the planned modifications and surveillances, may not be adequate to provide for the rapid i depressurization need."
_ Response As discussed above, for cold shutdown under nomal operating conditions the design of APSS meets the staff position in BTP RSB 5-1 for Class 2 plants for which manual operator actions are permitted if justified. For depressurization under the accident conditions considered, see the concerns / responses immediately following. In summary, subject to a final
. determination regarding the possible need to further verify (e.g., by testing) the effectiveness of the gas vent system as assumed in the analyses that have been done, the staff believes that the current design of APSS and the pressurizer gas vent systems with the planned modifications and surveillances provide adequate means of reactor coolant system (RCS) depressurization at an appropriate rate of depressurization to satisfy the j required safety function at Palo Verde.
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Concern "The ' rapid' depressurization function has been elevated (NUREG-1044) to a safety function but a dedicated safety grade system in this new plant has not been provided to perform it. (Of course, it has not yet been required of older plants which use nonsafety-grade PORVs)."
Response
When the APSS is not operable, the safety-related function of mitigating an SGTR accident is performed by the use of a safety-grade gas vent system from the pressurizer.
l Concern "The utility has now taken credit (after problems with the APSS during the testing program) for an alternate system (the gas vent system) for depressuriza-tion. , This would permit very, slow depressurization through a preferred 3/4-inch line or alternatively through a 7/32-inch orifice."
Response
When the APSS is not operable, the use of the gas vent system from the pressurizer has been assumed in an ANPP reanalysis of an SGTR accident. The results of this reanalysis show that the radiological consequences of the accident are within the limit of 10 CFR 100 guidelines when this alternate means of depressurization is used and that depressurization of the RCS is achievable.
Concern "The systems (APSS and vent) have numerous single failure vulnerabilities."
Response
The APSS is designed such that following a single failure in the system, manual operator actions outside the control room are required for system operation.
The staff has reviewed the design and concluded that the APSS design meets the staff position in BTP RSB 5-1 for a Class 2 plant. The design of the gas vent system from the pressurizer meets safety-grade standards including the single ,
failure criterion. ;
Concten !
l "The reliability of both of these systems depends on many valves that must open from a normally closed position and on the operability of several air-operated valves."
Response
The valve arrangement has been evaluated against the single failure criterion.
The air-operated valves are designed to fail to their safe position upon loss of non-safety grade air supply. The air-operated valve located in the RWT comon water supply line has been administrative 1y locked into its open position to assure a flow path.
The systems are designed such that the APSS would have a flow path available
, with a postulated single failure of a safety-grade component or power supply to the valves. In some cases, manual operator actions are required to establish a flow path for the APSS. This is pennitted for a Class 2 plant with respect to implementation of BTP RSB 5-1. In addition, the gas vent system from the
. pressurizer meets safety grade standards, including the single failure criterion.
IV. Conclusion In suma y, the staff conclud s that: 1) the safety-grade gas vent system from the pressurizer provides sufficient RCS depressurization for SGTR mitigation, and 2) the enhancements, technical specifications and schedules described in Palo Verde SSER 9 provide reasonable assurance that the APSS will perform plant cold shutdown per BTP RSB 5-1. Thus, the staff finds the Palo Verde design regarding the capability of RCS depressurization meets current regulatory requirements as stated in NUREG-1044. The decision regarding PORVs for CE plants without PORVs should be deferred and incorporated into the technical resolution of USI A-45.
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