IR 05000070/1978002
| ML20052A753 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos File:GEH Hitachi icon.png |
| Issue date: | 05/11/1978 |
| From: | Canter H, Crews J, Dodds R, Fish R, Kirsch D, Pate R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML20052A734 | List:
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| References | |
| FOIA-81-483 50-070-78-02, 50-70-78-2, NUDOCS 8204290127 | |
| Download: ML20052A753 (11) | |
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U. S. NUCLEAR REGULATORY COFMISSION 0FFICE OF INSPECTION AND ENFORCEMEili
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REGION V
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Report No. 50-70/78-02
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Docket No. 50-70 License No. TR-l Safeguards Group Licensee:
General Electric Comoany Vallecitos Nuclear Center Pleasanton, California 94566 Facility Name: General Electric Test Reactor (GETR)
Inspection at: GETR Inspection Conducted: April 26-27, 1978 I
8!k Inspectors:
TT. Dodds, Reactor Inspector sate' Signed
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H. L. Canter, Reactor Inspector Date Signed 125?&A dvhr
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R. Fis Reactor Inspec, tor
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Y D. Kitsch, Reactor Inspector Date' Signed S/Hf?S'
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R.'Pae,l}ec*orInspector
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Approved By:
J. L./ Cr'ews(, Chief, Reactor Operations and Date' Signed
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p Nuclear Support Branch Summary:
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Special Insoeccion on April 26-27,1978 (Report No. 50-70/78-02)
Areas Inspected:
Special unancounced inspection of allegations of
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unsafe conditions received in an anonymous letter at Region V on April 24, 1978.
This inspection involved 55 regular inspector hours by five NRC inspectors.
Results:
N,o items of noncompliance or deviations were identifie'd by the inspectors.
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DETAILS
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1.
Persons Contacted
- R. W. Darmitzel, Manager, Irradiation Processing Product Section
- D. L. Gilliland, Manager, Reactor Irradiations W. H. King, Manager, Nuclear Safety Technology C. L. Cain, Manager, Radialogical and Environmental Protection
- R. C. Chalberg, Reactor Analyst
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N. Fifer, Project Engineer W. A. Fletcher, Radiation Monitor
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D. Hoggett, Manager, Licensing Renewal l
C. Hooker, Supervisor, Radiological Protection W. Kretuel, Reactor Operator
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H. Mohr, Environmental Specialist
- E. J. Strain, Muclear Safety Technology Engineer
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W. P. Springsteen, Supervisor, Planning and Materials P. Swartz, Manager, Plant Engineering and Maintenance
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The inspectors also talked with and interviewed several other licensee employees., including members of the technical and engineering staffs, technicians, and reactor operators.
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- Denotes those present at the exit interview.
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Allegation Letter Enclosed as Attachment 1 to this report is a copy of the letter l
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which the Region V. office received in the mail on the morning of April 24,1978.
The letter mentions six " reasons for not granting General Electric Nuclear Test Reactor in Pleasanton, California a license for start-up."
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3.
Results
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Allegation
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"The reactor is unsafe because the reactor canal concrete is (
crumbling and powdery.
Even with the canal liner it is leaking l
radioactive water, about 300 gal an hour."
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l Inspection Findings l
l The r'esults of compression tested cylinders.from the original
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l construction of the reactor pool and canal were reviewed.
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General Electric (GE) had made plots of the break strengths at I
7, 28, and 90 days for each type of concrete.
All the plots I
had the characteristic increase in strength with time that exceeded the 3000 psi requirement of the construction specifi-cation.
Five cylinders were cored from the reactor biological
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shield (reactor pool wall) in January 1978.
The break strengths of these cylinders all exceeded 3000 psi and had increased in strength with time (continued hydration) approximately along the original curves.
These results indicate the concrete had increased in strength since placement in 1957, as would be normally expected.
The reactor pool was lined with stainless steel during the original construction.
The fuel storage canal was lined with stainless steel in April 1975 to restrict water seepage through cracks in the canal walls.
Therefore, the cor. crete on the inside of the reactor pool and canal could not be inspected during this inspection.
The appearance of the inside of the canal was discussed with the Project Engineer who was assigned responsibility for the canal liner installation.
The Project Engineer had several pictures of the canal surface before the liner was installed.
There appeared to be only minor local surface deterioration of the concrete in the area of the cobalt capsules due to high irradiation and some deterioration in a construction joint that was approximately four inches wide, six inches deep and ten inches long.
The damage at the construction joint was reported to have been cleaned back to sound material and repaired with epoxy grout.
The damage to the concrete surface near the cobalt capsules was less than one inch deep and did not require repair, Also, GE personnel reported. that in June,1974 a three-inch diameter hole was cut in the pool liner as part of a decon-tamination effort.
The concrete was inspected under the removed portion of liner.
The concrete surface was reported to have had the appearance of exposed aggregate.
The surface mortar down to the first layer of aggregate (less than one inch deep)
had been removed.
The concrete was drilled to place an anchor for repairing the hole in the liner and was
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reported to be sound.
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The NRC inspectors observed the outside surface of the reactor
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pool and canal walls from inside the equipment room.
All the
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walls appeared sound except one area (approximately ten square feet) in the northeast part of the equipment room approximately 18 feet above the equipment room floor inside the containment
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building.
The surface of this area appeared to be soft and
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i was relatively easy to scratch to approximately 1/2 inch depth with a screwdriver.
The extent of the deterioration below the
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surface could not be determined by the inspectors.
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In summary, the concrete walls for the GETR reactor pool and canal appear to be structurally sound.
The surface deterioration found was structurally insignificant considering the walls are l
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3-4 feet thick and the floor is 7 feet thick.
However, GE personnel comitted to further evaluation to provide con-firmation that the surface condition found on the outside surface of the canal wall in the NE corner of the equipment room does not extend beyond the surface.
With respect to 'the radiological aspects of this allegation, according to the licensee, water leaking from the canal remain's within the containment building.
The average leakage rate since January, 1978 to date has been 333 gallons per hour.
The inspector independently measured the current leakage rate to be 250 gallons per hour.
The leakage path is through the canal liner to the basement sump.
The water is then pumped to underground contaminated water tank 103 (25,000 gallon capacity) and then through a demineralizer to tanks 101 or 102 (clean drain tanks with 25,000 gallon capacities).
From tanks 101 or 102, the water
is sent through another demineralizer to demineralized water tank 104 (50,000 gallon capacity) and back to the pool or canal.
The water processing system has a flow rate capacity of about 50 gallons per minute.
In 1974, prior to installation of the pool liner in Apri1 1975, the canal leaked at a rate of 1700 gallons per hour, mostly from a crack in the canal wall near the canal to pool transition joint.
This leakage was reduced by placing epoxy in the crack which lowered the leakage rate to about 500 gallons per hour prior to installation of the liner.
The licensee's environmental monitoring program includes collecting well water samples to detect whether radioactive
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materials from site sources, including GETR, have escaped to the aquifer.
Four wells have been included in the sample
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program and are located in approximately a 180 degree (east to
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south to west) direction from GETR. According to the facility records, quarterly samples were obtained from three well locations during 1977.
The fourth location, a well on private property across the highway from the site, was not sampled because it was locked and unaccessible. All four wells were
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sampled in March 1978.
The well water samples have been analyzed for gross alpha, beta-gamma, and tritium activities. The mimimum detection
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limits for these analyses are 10, 30, and 2000 picocuries per liter, respectively.
The records showed that less than detectable quantities of gross alpha, beta-gamma, and tritium activities were found in the well water samples collected
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during 1977 and March 1978.
These results were the same as
those for well water samples co'llected during the previous four years.
According to the licensee, they would investigate any result that was above the minimum detection limit.
No items of noncompliance or deviations were identified.
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Allegation
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"The primary heat exchanger has a crack in the wall and is leaking water."
Inspection Findings The primary heat exchanger does have a crack in the top of the aluminum shell wall (see Licensee Event Report dated June 18, 1976).
The secondary water leakage through the crack has been stopped by use of a " mechanical seal" consisting of a neoprene gasket, held in place with a pressure plate and steel bands.
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The area is inspected at the end of-each operating cycle to insure that there is no leakage.
The licensee plans to install
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a nozzle over the cracked area as a permanent repair.
The inspectors examined the repaired area with the system operating at full secondary pressure of 20 psig.
No water seepage could be' detected. A spare heat exchanger has been purchased and is available for installation should it be required.
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Allegation
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"The primary pipe system has Cobalt-60 pellets circulating thru it, it is highly radioactive and some pellets are caught in a few of the weld backing rings.
It is a safety hazard."
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Inspection Findings The inspection included a discussion and examination of records relating to radiation levels associated with the primary coolant system. An inspection in June 1975 by Region V'
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(IE Inspection Report No. 50-70/ 75-05) included an examination of the extended shutdown during which 70 to 90 percent of the cobalt pellets were removed from the primary system.
According to the licensee, there has been no elevated radiation levels l
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due to discrete pellets for some time; however, following the early 1975 extended shutdown, some radiation increases could be identified with pellets.
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Survey records were examined to evaluate the possible continuing
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effect resulting from the cobalt pellet problem.
In the equipment room, radiation levels in 1972 were similar or slightly higher than those found in July 1977 (maximum readings of 6 R/hr in 1972 vs. 3 R/hr in 1977).
In the sub-pile crea (gallery) radiation levels have been increasing over the past 1-2 years.
An October 6,1977 survey record showed the following readings:
General areas 2.2 to 3 R/hr; entrance 1 R/hr; maximum level at control rod approximately 1000 R/hr; area approaching control rods 5 to 25 R/hr.
The record of a September 13, 1976 survey of the primary cooling system showed radiation levels of 1 to 800 mR/hr whereas a February 7,1978 survey showed levels of 50 mR/hr to 15 R/hr.
The licensee noted that the radiation levels are very location dependent and a slight change in the detector location can result in a significant change in the reading.
Thus some of these differences in survey results can be attributed to the location of the detector rather than an increase in the radiation level.
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No items of noncompliance or deviations were identified.
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Allegation.
"How can pipe restrainers work when the primary pipe welds have never been inspected."
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Inspection Findings
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The construction specification for the original construction of GETR requir,ed visual and hydrostatic inspection of the primary system welds. Also, a percentage of the welds were required to be radiographed.
No records of these inspections were readily available at the facility.
GE personnel stated they believe these records exist, but they were not able to
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locate them during the current inspection.
There were no requirements for the licensee to keep these records.
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The welds in th6 primary system were visually inspected in 1962.
The inspector assigned to GETR at that time stated in his report of inspection dated November 11,1962 that a portion of the system (a wye section) had been radiographed and that the
entire system was visually inspected during a hydrostatic pressure test. A random sample of the primary system welds (approximately 35 welds) were visually inspected by the NRC inspectors during the current inspection.
No defects were
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identified in the welds examined.
It is concluded that the primary system welds were inspected.
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However, GE has committed to continue to search for the l
inspection records fr'em 1957-58 to provide more conclusive evidence that construction inspections were performed.
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Allegation
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"The first floor subpile room should be inspected by the NRC for safety violations."
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Inspection Findings The initial access control has been established at the entrance to the containment building.
The reactor operator in the control room has audio and visual (TV) contact with the entrance to the personnel airlock.
Persons entering the containment building must inform the reactor operator of their identity and why (or for what purpose) they are entering.
Associated with this control are the administrative procedures covering the authorization to perform activities inside the containment building and radiation work permits.
The Shift Supervisor and Radiation Monitor must approve the latter and a copy of the approved permit is posted in the change area.
According to the licensee, either the Radiation Monitor or a Reactor Operator will be present during those periods when work is performed in the equipment or sub-pile rooms.
The entrance to the equipment room has been provided with a high radiation area control device.
The device provides an audible and visual alarm at the room entrance and in the control room.
The equipment room door is normally locked with a padlock and administrative procedures require a visual check to confirm that persons have not been locked in the recm following work activities.
At the time of this inspection work was being performed in the equipment room and the control device was observed to be functioning.
Also, a Radiation
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The entrance to the equipment room was posted in accordance with 10 CFR 20.203(c)(1).
The entrance to the sub-pile area is in the equipment room.
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There is a locked metal gate at the entrance to the sub-pile
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area.
A control device that provides an alarm at the sub-pile entrance and in the control room is actuated when the gate at
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,the entrance to the sub-pile area is, opened.
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The primary purpose for working in the sub-pile area is to disconnect flange bolts and switches in connection with work
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on the control rods and their drives.
This work usually involves three persons (a manipulator, an electrician and an observer).
Personnel monitoring devices include pocket ion chambers, film badges and finger ring badges when applicable.
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The last such work was performed on September 20, 1977.
The facility exposure records showed pocket ion chamber readings of 250-1000 mR, film badge readings of 840-900 mrem and finger ring readings of 1050 to 3700 mrem.
These exposures were higher than those for three other periods of work in 1977 and one on April 9,1976, but still within Part 20 requirecents.
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No items of noncompliance or deviations were identified.
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Allegation
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"The reactor is hooked up to a seismograph, but it does not work."
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Inspection Findings
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There are two independent seismically related " systems" at the GETR.
The " seismograph" apparently referred to in the allega-tion letter, is a Strong-Motion Recorder or Seismometer Model AR-240 made by the Earth Science Division of Teledyne Systems Company.
The unit was installed in April,1968 for the purpose of recording seismic activity.
The unit is battery operated and has a built-in battery charger.
It has never been " hooked up" to the reactor; it has no facility to " hook up" to the reactor; and, it has never been required to be " hooked up" to
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the reactor.
The unit has been used only for monitoring seismic activity. When the recorder is activated at a Modified Mercalli (1931) III level, a Panalarm annunciator actuates in the control room which warns of seismic activity. Also, a Remote Action Indicator (Model AR-210) is actuated in the control room.
This instrument records on a digital counter how much film tape was run through the Strong-Motion Indicator during the seismic event. The film is subsequently developed
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showing a record ' f the seismic amplitude, duration, and I
o ground acceleration in three. dimensions.
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The Strong Motion Recorder and Indicator are on a semiannual preventive maintenance and calibration schedule.
Records for all calibrations since May,1976 were examined with no dis-i
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crepancies observed. Also, the film for the June 20, 1977 earthquake centered east of Livermore, California was examined.
t There was no evidence, observed by the inspectors, that this
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instrument has been inoperative in the past two years.
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The second seismically related " system" at the GETR is a set
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The switches were built by the California Academy of Sciences. They are oil damped with a one second period pendulum and platinum coated cone and
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l ring contacts located near the center of oscillation.
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l horizontal earthquake acceleration-period combination that causes a differential motion of pendulum center of oscillation to base levels equal to contact spacing will close the switch.
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The gap setting is such that an earthquake equivalent to a
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Modified Mercalli Scale III will close the switch and cause a i
reactor scram.
During the June 20, 1977 earthquake mentioned earlier, this system operated to trip the reactor.
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The two seismic switches operate independently to trip the reactor.
The switches are en the regular alibration and
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maintenance schedule and are checked every three cycles of reactor operation.
This check includes inputing a signal at the pendulum and following system response.hrough to its alarm and trip function in the control room.
No discrepancies were noted in the examination of maintenance and calibration records for these switches.
No items of noncompliance or deviations were identified.
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Unresolved Item Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable items, items of noncompliance, or deviations.
An unresolved item disclosed during the inspection is discussed in Paragraph 3.a.
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Exit Interview The inspectors met with licensee representatives (denoted in Paragraph 1) at the conclusion of the inspection on April 27, 1978.
The inspectors summarized the purpose and scope of the inspection and the findings. With regard to the unresolved item mentioned in Paragraphs 3.a and 4, the licensee representatives stated that they will confirm the extent of the surface concrete condition found in the northeast corner of the equipment ro'om.
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ATTACHMENT 1
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ATTACHMENT 1
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Anonymous Letter Received by Region V on April 24, 19'78
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s Here are so=e. reasons ror not granting General. Electric anclear less acactor in Pleasanton,. Caluornis' a license for start up.
The reactor is unsafe because the reactor canal concrete is crumbling ar.d pewdery.
2:ven vita ec car.al liner it is leaxing radioactive water,about 300 gal an hour.
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no prirary neat exchanger has a crack in the vall and is.leac _g water.
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no. pricary pipe systen nas Cotnit-cu pellets. circulating thru it.. it is.bigaly radioactive ana sous pellets are. caught in a few. of the veld cacking. rings.
- LL is.a sarety nazard..
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How can pipe. rostrainers,voric v en one prima $/ pipe velds have never been inspec6ea Tho nrst floor subpile room shculd bo in'spectcc ey Ice sh for safety violattom..
Tno reactor is,noor_ea up to a seismograph. but it dcesinot voric.
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