ML20050B925
| ML20050B925 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 03/15/1982 |
| From: | Hodges M Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20050B894 | List: |
| References | |
| NUDOCS 8204070562 | |
| Download: ML20050B925 (6) | |
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03/15/82 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE AT0f1IC SAFETY AND LICENSING BOARD In the Matter of
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ARIZONA PUBLIC SERVICE
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Docket Nos. STN 50 528 COMPANY, et al.
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STN 50-529
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STN 50-530 (PaloVerdeNuclearGenerating
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Station, Units 1, 2 and 3)
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NRC STAFF TESTIl10NY OF M. W. H0DGES i
ON CONTENTION N0. 68: ATWS Q. Please state your name and position with the NRC.
A. My name is M.W. Hodges and I am employed by the Nuclear Regulatory Commisison as a Section Leader in the Reactor Systems Branch, Office of the Nuclear Reactor Regulation. One of my responsibilities is the evaluation of the implementation of ATWS requirements for all light water commercial power reactors.
Q. What is the purpose of your testimony.
A. The purpose of this testimony is to respond to Ms. Hourihan's contention 6B which asserts that:
The Applicants have not incorporated measures designed to mitigate a postulated ATWS evert.
Q. What is ATWS?
A. ATWS is an acronym for " anticipated transients without scram".
Anticipated transients are deviations from normal operating conditions which are expected to occur one or more times during the operation of a nuclear power plant. A scram is the termination of the nuclear reaction 8204070562 820315 PDR ADOCK 05000528 PDR
, by rr.pid insertion of control rods. An ATWS occurs if there is the failure to rapidly terminate the nuclear reaction when such rapid termination is required, as a result of an anticipated transient, to prevent violation of transient design limits.
Q. What is the status of the,ATWS issue?
A. ATWS has been the subject of numerous Staf' reports.
In March 1980, Volume 4 of NUREG-0460, " Anticipated Transient Without Scram for Light Water Reactors", was issued describing the proposed type of plant modifications the staff believes necessary to reduce the risk from ATWS events to an acceptable level.
In September 1980, Staff presented these recommendations to the Commission and also recommended a rulemaking proceeding to establish ATWS criteria. The Comission has recently published a proposed rule which would finalize the permanent requirements for safeguarding against an ATWS event. 46 Fed. Reg. 57521 (November 24, 1981).
Q. What is being done to provide protection against ATWS events in the interim?
A. It is our expectation that for operating plants the necessary plant modifications will be implemented in one to four years following a Comission decision on ATWS. As a prudent course, in order to further significantly reduce the risk from ATWS events during the interim period before completing the plant modifications determined by the Commission to be necessary, we require implementation of emergency operation of procedures and operator training. These interim requirements are discussed in Section 15.3.9 of NUREG-0857 " Safety Evaluation Report related to the operation of Palo Verde Nuclear Generating Station, Units 1, 2 and 3" r
o (SER) which specifies that Applicant will:
(1) Develop emergency procedures to train operators to recognize anticipated transient without scran event, including consideration of scram indicators, rod position indicators, flux monitors, pressurizer level and pressure indicator, and any other alarms annunciated in the control room with emphasis on alarms not processed through the electrical portion of the reactor scram system.
(2) Train operators to take actions in the event of an anticipated transients without scram, including consideration of manually scramming the reactor by using the manual scram button, prompt actuation of the auxiliary feedwater system to assure delivery to the full capacity of this system, and initiation of turbine trip. The operator should also be trained to initiate boration by actuation of the high pressure safety injection system to bring the facility to a safe shutdown condition.
This discussica of ATWS in the SER was prepared by the Reactor Systems Branch.
I have reviewed this discussion and can affirm that (1) the requirement of procedures and training as discussed in Section 15.3.9 is consistent with the interim requirements used for other pressurized water reactors and (2) while the Commission has published in the Federal Register a proposed rule to require design and operational improvements in nuclear power reactors to reduce the liklihood of occurrence and consequences of ATWS events, these interim requirements provide adequate ATWS mitigation until a formal rule is issued and implemented.
Q. Has the Applicant committed to develop the emergency procedures and to train operators for ATWS pending final commission determination.
A. Yes. Section 15.3.9 of the SER, as well as the affidavit of F. W. Hartley attached to the " Joint Applicant's Motion for Summary Disposition of Intervenor's Contention 6B," (Motion) reflects a committment by the Applicant to develop and submit the procedures I
mandated by the Staff requirements at least 60 days prior to fuel load.
. Q. What are your conclusions concerning Ms. Hourihan's Contention 5.
A. Contrary to the Intervenor's claim that the Joint Applicants have not incorporated measures designed to mitigate a postulated ATWS event, the Staff has developed interim requirements for operating procedures and operator training to accomplish this purpose pending final resolution of the ATWS issue by the Commission. The Applicants have committed to adopt these interim requirements.
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Marvin W. (Wayne) Hodges i
Professional Qualifications Reactor Systems Branch Division of Systems Integration U. S. Nuclear Regulatory Commission I am employed as a Section Leader in Section B of the Reactor Systems
~~ Branch, Division of Systems Integration.
I graduated from Auburn University with a BS degree in Mechanical Engineering in 1965.
I received a Master of Science degree in Mechanical Engineering from Auburn University in 1967.
In my present work assignment at the NRC, I supervise a team'of en'ineers g
involved in the review of boiling water reactors.
Prior to July 26, 1981, I served as principal reviewer in the area of boiling' wat'cr reactor systems.
I also participated in the review of analytical mode'Is used in the licens'ag evaluations of boiling water reactors and I had the technical review responsibility for many of the modifications and analyses being implemented on boiling water reactors after'the Three Mile Island, Unit 2 accident.
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-In addition, I participated in the review of the core protection calculatbrforANO-2andsubsequentCombdstionEngineeringplantsand
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consequently I am familiar with systems behavior for CE plants.
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As a member of the Bulletin and Ord'r's' Task ~ force which was formed aftpr '
theTHI-2 accident,Iwasresponsiblefnjltherev'iewofthecapabilityof
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loss-of-coolant accidents.
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served as a consultant to the RES representative to the program ss 3
management group for the BWR Blowdown / Emergency Core Coolfog Program.
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Prior to joining the NRC staff in March,15V4, I.wss empicked by E. I. DuPont at the Savannah River Laboratory as a, research engin' der.. At
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,q-of the reactors at the Savannah Rivec Plant.. I Wso*perfonned safety Qy limit calculations and participated ins th '.L evelop.nent of" analytical t,d.g" d
models for use in transient analyses at Savannah kiver. My tenure at SRL N,
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, s From September 1965 to June 1967, while in graduate school,,I t.tught i
N courses in thermodynamics, statics, n'echanical engineering e
measurements, computer programming and assisted in a cour3*.in th,e ':.\\
history of engineering.
Durino the suurse\\r of 1966, I worked at the 3
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