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NOV 2 91978 MEMORANDUM FOR:
E. J. Brunner, Chief, RO&NSB, RI F. J. Long, Chief, RO&NSB, RII G. Fiorelli, Chief, RO&NSB, RIII G. L. Madsen, Chief, RO&NSB, RIV J. L. Crews, Chief, RO&NSB, RV FROM:
E. L. Jordan, Assistant Director for Technical Programs IE
SUBJECT:
COMMISSION RESPONSE REGARDING GAO REPORT ON OFFGAS EXPLOSIONS Enclosed for your information is a copy of the Commission response to Congressman Brooks describing NRC action on offgas explosions.
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. Jordan, Assistant Director fo Technical Programs Division of Reactor Operations Inspection
Enclosure:
Memo J. M. Hendrie to Jack Brooks dtd 10/26/78 CONTACT:
C. J. DeBevec, TP 49-28180 f
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w OPPICE OF THE CHAIRMAN The Honorable Jack Brooks, Chairman Committee on Government Operations-United States House of Representatives Washington, D. C.
20515
Dear Mr. Chairman:
In an August 4,1978 letter, the Comptroller General provided a description of the offgas explosions that have occurred at operating boiling water nuclear power plants and an 1ssessment of the actions of the Nuclear Regulatory Commission in connection with these explosions.
In addition to describing actions taken by the Commission to minimize offgas explosions the Comptroller General -recommended that the Chair-man, Nuclear Regulatory Commission:
" Accelerate the process for requiring and implementing the actions aimed at minimizing gas explosions at nuclear power plants. These actions should include ventilation of closed areas where explosive gas may accumulate, assuring seal in-tegrity, and protection of piping from ignition sources."
Before responding to the GA0 reconmendations, a brief overview and history of this matter is appropriate. First and most important, boiling water reactor (BWR) offgas systems are not reactor-safety rclated systems and their malfunctions have not constituted a health hazard to the public.
Technical ' analysis, supported by operating experience, has shown that a release of radioactivity, significant to the public health, due to an of fgas explosion is unlikely.
In fact, of the offgas explosions that occurred, none have resulted in radioactivity release to the environment above a small fraction of that allowed by Federal regulations for nomal plant operation. Even though the safety significance of offgas explosions does not constitute a hazard to the health and safety of the public, the Commission has taken actions in this regard, because we recognize that injuries to plant workers and property damage can occur from these mal func tions.
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The Honorable Jack Brooks ' Since 1974, reactors in design and construction stages have been re-quired to improve the integrity of the offgas system drain seals, which represent potential sources of combustible offgas leakage, as part of our licensing reviews.. For op'erating reactors experiencing offgas problems, the Commission has required preventative measures on a case-by-case basis.
In February 1978, the Commission issued an Inspection and Enforcement Bulletin to all BWR Ifcensees requesting their review of the adequacy of designs and operating practice that would minimize offgas explosions. This Bulletin requested licensee responses in several areas including the GA0 recommendations concern-ing ventilation of closed areas, assuring seal integrity and protection of piping from ignition sources.
In March 1978, a generic technical report on offgas system experience was completed (NUREG-0442). A copy of that report-is enclosed.
As indicated earlier, the Comptroller General's report recommends that the Commission accelerate the process for requiring and implementing actions aimed at minimizing gas explosions at nuclear power plants.
The Commission does not consider it justified to accelerate the pres-ent program in this area because it would detract from the Commission's efforts devoted to other issues which are of safety significance.
Although we recognize that the present program could have been started earlier, a sound program has been implemented.
In response to the In-spection and Enforcement Bulletin, licensees hue stated that they have taken precautions to limit offgas explosions. The features of the spe-cific plant offgas system at each operating BWR will be independently examined by an NRC inspector before the end of November. The purpose of these inspections is to review the licensee's system in light of their response to the laE Bulletin (see Attachment I of NUREG-0442). Upon com-pletion of these inspections, review and assessment reports will be pre-pared for each reactor and will be used to detemine if any additional licensing or other regulatory actions are necessary.
These reports are scheduled to be completed this December. The full staff review of the offgas systems is estimated for conpletion by June 1979.
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The lionorable Jact Brook 5 3-In conclusion, the Caission believes that resources cunnitten to this issue are pror.ortional to its safety significance. The present schedule of review antf inple:2entation is timely and consistent with the t,est utilization of the Com:1ssion's resources.
Si ncerely, 2
Joseoh . l'endrie Chairman Enclosurc:
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Technical Revert on Operatina Experience with Soiling '*ater Reactor Of fcas Syste,s. Ul@EL 9442, April 197t, DISTRIBUTION cc: 9epresentative Frant-norton g7 EEB Reading EDO Reading L. Ggssick N. tioseley S. Chilk R. DeYoung J. Kelley V. Stello C. Kamerer B. Grimes K. Pedersen J. Collins J. Fouchard G. Knighton H. Shapar L. Barrett J. Davis R. Lo C. Smith OCA R. Minogue OIA S. Levine PDR H. Denton LPDR E. Case SECY (73-529)
M. Groff (NRR-04335)
RETYPED PER fl. BRIDGERS - SEE ATTACHED YELLOW FOR PREVIOUS CONCURRENCES.*
IDENTICAL LETTER SENT TO ADDRESSEES LISTED ON PAGE 4.
APPROVED BY COMMISSION AS SECY 78-S29.
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l The lionorable Jack Brooks 4-101/iTICAL LETTER SENT TO THE FOLLOWIiG-The Honorabic Abraham Ribicoff. Chairman Corr.ittee on Coverneental Affairs United States Senate Washington, D. C.
20510 Sen. Charles A. Percy cc:
The lionorable Gary Hart, Chairman Subccmriittee on Nuclear Regislation Committee on Environment and Public Works United States Serate Washington. D. C.
20510 Sen. Jaines A. McClure cc:
The !!onorabic tbrris K. Udall Chairnus Subconnittee on Enercy and the Envirunrent Cocraf ttee on Interior and Insular Affairs United States llouse of Representatives Washington, D. C.
20515 cc: Rep. Robert Baurun The lionorable John D. Dingell, Chairnar.
Subcomittee on Energy and Power Comittee on Interstate and Foreign Cor:rerte United States }louse of Representatives Washington, D. C.
20515 cc: Rep. Clarence J. Drovn i
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