ML19312D952
| ML19312D952 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 05/27/1980 |
| From: | Jay Collins Office of Nuclear Reactor Regulation |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| CON-NRC-TMI-80-095, CON-NRC-TMI-80-95 NUDOCS 8006020118 | |
| Download: ML19312D952 (6) | |
Text
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UNITED STATES ska % g #o, NUCLEAR REGULATORY COMMisslON
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WASHINGTON, D. C. 20656 E
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f May 27,1980 NRC/TMI-80-095 MEMORANDUM FOR:
H. R. Denton, Director.
Office of Nuclear Reactor Regulation B. J. Snyder, Program Director, TM1 Program Office FROM:
J. T. Collins, Deputy Program Director, TMI Program Office l
SUBJECT:
NRC TMI PROGRAM OFFICE WEEKLY STATUS REPORT Enclosed is the status report for the week of May 17-23, 1980.
b'd&'
av ohn T. Collins Deputy Program Director TMI Program Office
Enclosure:
As stated cc:
EDO OGC Office Directors Commissioner's Technical Assistants NRR Division Directors NRR A/D's Regional Directors IE Division Directors X005 X0MA HEW EPA Public Affairs, RI T. Elsasser TM1 Program Staff 3ooeoso//IP P
NRC TMI PROGRAM OFFICE WEEKLY STATUS REPORT Week of: May 17-23,1980 Plant Status Core Cooling Mode:
Cyclic natural circulation in the "A" reactor coolant system (RCS) loop via the "A" once through steam generator (OTSG), steaming to the main condenser, and RCS loop-A and B cyclic natural circulation to reactor building ambient.
Available Core Cooling Modes: 0TSG "B" to the main condenser; long term cooling "B" (OTSG-B); decay heat removal.
RCS Pressure Control Mode:
Standby Pressure Control (SPC) System.
Backup Pressure Control Mode: Makeup system in conjunction with letdown flow (Emergency use only due to suspected leaks in the seal injection system).
Major Parameters (As of 0600, May 23,1980) (approximate values)
Average Incore Thermocouples: 156 F Maximum Incore Thermocouple:
192 F RCS Loop Temperatures:
A B
Hot Leg 151 F 155*F Cold Leg (1) 77*F 106 F (2) 78"F 122*F RCS Pressure: 84 psig (Heise) 94 psig (DVM - controlling)
Pressurizer Temperature:
109 F Reactor Building:
Temperature: 78 F Pressure:
-0.7 psig (Heise)
Water level: Elevation 290.2 f t. (7.7 ft. from floor) via penetration 401 manometer (see major activities below)
Environmental & Effluent Infonnation 1.
Liquid effluents from TMI-l released to the Susqueharna River, after processing, were within the limits specified in Technical Specifications.
2.
No liquid effluents were discharged from TMI-2.
3.
Results from EPA monitoring of the environment around the TMI site were:
EPA environmental stations registered background levels for air particulate and water samples.
2 Gas / Air (Kr-85) sample results during the period May 9 through May 16, 1980, were: Goldsboro - 23 pCi/m3 Center - 34 pCi/m3, Middletown - 24 pCi/m3, TMI Observation i
, and Bainbridge -
24 pC1/m3 The EPA states that the Kr-85 background concen-tration in the vicinity of TMI to be between 20 and 40 pCi/m3, 1
Instantaneous direct radiation readings showed levels within the range of natural background (0.008 mR/hr to 0.020 mR/hr) at all of the EPA monitoring locations during this reporting period.
I 4.
NRC Environmental Data The West Screen House continuous air sample (HP-216) for the sampling period May 15 through May 21, 1980, has been delivered to the EPA Coordination Center for analysis.
Results of the environmental TLD neat.urements for the period March 18 to April 30, 1980, indica'.e no ganna levels above natural background.
Fifty-eight TLD's registerra doses ranging from 0.09 mR/ day to 0.18 mR/ day. Average dose was O.13 mR/ day. These dose rates are consistent with natural background radiation in the TMI area.
The licensee provided the following monthly inventory of Kr-85 releases for 1980:
January - 80 C1, February - 80 Ci, March - 63 Ci and April - 69. Total through April - 292 Ci Kr-85.
5.
Radioactive material and Radwaste shipments offsite were as follows:
On Monday, May 19, 1980, a Unit 2 reactor coolant sample and smear sample was sent to the Babcock and Wilcox (B&W) facility, Lynchburg, Virginia, for chemical ano radiochemical analysis.
On Wednesday, May 21, 1980, a Unit 1 LSA compacted waste shipment was sent to Barnwell, South Carolina.
Two Unit 2 waste shipments. LSA boxes and LSA 55 gallon drwas, are on hold pending further licensee evaluation of the isotopic content of the compacted and uncompacted waste.
l There was a temporary postponement of radioactive waste ship-l ments to Richland, Washington, due to road conditions in Washington State after the recent eruption of Mt. Saint Helen volcano.
6.
EPICOR II Processing Status:
(auxiliary building approximate l
quantities)
Amount processed this week:
20,000 gallons Amount processed to date:
300,000 gallons Amount to be processed:
144,000 gallons
3 Major Activities (Past and Present) 1.
Reactor Building Entry. At approximately 9:00 p.m., on May 20, 1980, the licensee attempted to enter the TMI-2 reactor building, the first such attempt since the March 28 accident.
The procedure was terminated af ter repeated attempts failed to open the inner door of the containment personnel airlock.
It was thought that the possible causes for the failure to open the door were:
seal surface adhesion or door hinge binding due to corrosion; and/or suction effect due to vacuum condit.ans between inner door seals.
However, a licensee representative conducted a debriefing with the NRC TMI Program Office staff concerning the events that occurred on May 20, 1980.
Review of this information indicated new developments that must be explored prior to further attempts to actually open the airlock inner door as noted below.
After the decision to terminate the procedure, the airlock restoration to normal phase was initiated and this included making the inner /
outer door interlock operable which prevents both doors from being open simultaneously.
(This interlock is presently operable.)
During this evolution it was noted by the licensee that the inner door handwheel was beyond the closed stop position by approximately 1 turn. This meant that the 1-2 turns of full travel experienced by the operators did not include that section of trafel to actually operate the door roller mechanism which permits openf ng the inner door. The 1-2 turns did include that section of travel to open the air pressure equalizing valve between the reactor building and airlock.
The licensee suspects that the inner door handwheel did not go beyond the equalization position due to a differential pressure
( AP) safety interlock malfunction.
Normally this interlock pre-vents the inner or outer door from opening if differential pressure across the door is greater than 1 psig.
The interlock does permit equalization as was experienced during the events of May 20.
On Friday, May 25, 1980, the airlock was entered again, with the inner door closed maintaining containment integrity, to trouble-shoot the electrical / mechanical aspects of the AP safety interlock for both doors using the outer door as a model.
Electrical checks (continuity, solenoid deenergization) proved satisfactory. However.
it wa; noted that the slight distortion of the operating mechanism on the outer door did cause the aP safety interlock solenoid pin to stick in an energized position enforcing the interlock function to prevent door opening.
This distortion was simulated by maintaining a grip on the door handwheel. When the handwheel was released the solenoid returned to the deenergized position.
i l
4 Based on this infonnation the Ap safety interlock malfunction is The solenoid / pin assenbly is located inside the not ruled out.
reactor building for the inner door. The next step in the licensee's plan for detemining why the inner door did not open is to equalize air pressure between the airlock and the reactor building (outer
.J door closed) and attempt to go beyond the air equalization position on the inner door handwheel. The inner door will be maintained closed by temporary mechanical means ("come-along").
No containment entry is planned.
2.
Reactor Building Sump Water Level Measurements _.
On Thursday, the Heise gage used in the detemination of reactor May 22, 1980, building water level via the decay heat system was isolated.
Measurements of water level was shif ted to manometer system through penetration 401. This shif t in measurements systems was necessitated over concern about excessive cycling of DH-V68, Containment Sunp Isolation to the Decay Heat System.
Failure of this valve was possible and could result in an unisolable reactor building leak.
The gage had to be isolated because of known leakage through DH-V5B, Borated Water Storage Tank (BWST) Isolation to the Decay Heat System. The resultant pressure head from the BWST would be greater than the range of the gage causing gage damage.
Mini Decay Heat Removal (MDHR) Syctem. While flow testing both of 3.
the MOHR pumps, af ter the system had been hydro tested, the licensee The leak was approximately detected a seal leak on the "A" pump.
1 gpm. The flow test was immediately teminated and the pumps shut-off. The pump manufacturer has been contacted to aid in detemining the cause of the leak.
The pump seals, because they are of a high grade quality, are not an 07f-the-shelf item.
The pump manufacturer is trying to obtain replacement seals from their customers' inventory.
If they can not be obtained from this source, it is estimated that there could be a 5 week delay because the seals would have to be special ordered.
4.
Ground Water Monitoring Samples Results.
Sample results are not yet available from the licensee for those samples taken on May 16, 1980.
Submerged Demineralizer System.
The cask support platform for the 5.
submerged demineralizer system (SDS) that will clean up containment building sump water was recently installed.
The platform spans the Unit 2 "B" spent fuel pool.
The 24-by-ll-by-2-foot device will support the ion exchange polishing unit and filter manifold which are a part of the 50S.
Workers have begun installing a filter support rack which will house the disposable filters used to remove undissolved solids from the water being processed.
The spent fuel pool was drained and decc.ataminated earlier in preparation for the installation of the SDS.
Equipment installation is scheduled to continue for the next 6-10 weeks.
5 Meetings Held with Public Officials and Interested Groups 1.
On May 20,1980, J. Collins. T. Elsasser, K. Abraham 6nd G. Sanborn responded to media inquiries concerning the unsuccessful attempt to enter the Unit 2 containment. They also attendad the Met-Ed press
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conference following the event.
2.
On May 21,1980, J. Collins, T. Elsasser, K. Abraham and G. Sanborn attended the press conference held by Met-Ed to discuss additional aspects of the unsuccessful containment entry attempt.
3.
On May.25, 1980, J. Collins addressed a group of concerned citizens of Lower Manchester Township at a meeting held at the Mount Wolf Lutheran Church.
Future Meetings 1.
On June 9,1980, J. Collins will meet with the Pennsylvania Arson 1
Association in Lancaster to discuss clean-up operations at TMI-2.
l 2.
J. Collins will present an invited paper entitled, "NRC Involvement During the TMI Accident" at the 1980 Annual Meeting of the American Nuclear Society, June 8-13, 1980, in Las Vegas, Nevada.
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