ML19345C284
| ML19345C284 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 10/30/1980 |
| From: | Reed C COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML19345C263 | List: |
| References | |
| 80-206, 801114-02, 801114-2, NUDOCS 8012040333 | |
| Download: ML19345C284 (6) | |
Text
., _
n Commont
.Ith Edison E
Dresden Nuct'e r Power St;ti;n R.R. #1 m.
/
Morris, Illinois 60450 7
Telephone 815/942-2920
[
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October 30, 1980 DJS Ltr. #80-206 Mr. James G. Keppler, Director Directorate of Inspection and Enforcement - Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137
SUBJECT:
Dresden Station Investigation into Water Losses S tified during September, 1980
REFERENCE:
(a)
R. Heishman letter to C. Reed dated October 17, 1980
Dear Mr. Keppler:
During the first week of September, 1980, allegations were made to a Chicago, Illinois newspaper that 300,000-400,000 gallons of water contaminated with low levels of radioisotopes had been released from Dresden Station into the environment during the preceding month.
This letter describes our contin-uing efforts to identify the most likely cause of the discrep-aucy in our water inventory sys tem.
On September 17, 1980, we met with you in your office to describe our initial efforts to identify obvious leaks and to account for the apparent water inventory loss.
All of our efforts concluded that there was no detectable threat to the health and safety of the public from any alleged water losses occurring from the site.
As we described to you, we conducted a walk-down and visual examination of all piping systems and equipment which could have been involved in a moaitored or un-monitored water release, and we found no discrepencier which might result in leakage to the environment. We tested most of the underground piping which contains contaminated water and again concluded that no leaks were occurring. A small portion of four piping runs could not be included in these_ tests, but other evidence indicated that no leakage was occurring from these lines.
l Other tests which we conducted to identify possible leak-age paths included an extensive special sampling program of storm sewers, the sewage treatment plants, and the vaste water treatment facility. This sampling program further confirmed 48 801 8012040 i, 3 3, b
DJS Ltr. #80-206
' October 30, 1980 that contaminated water losses were not occurring through t.hsae paths. We measured, using sophisticated ultrasonic flow testing devices, numerous piping runs where no other indication was possible and we concluded that no unusual flows were occurring from these lines. We also recalibrated many existing level indi-cators to ensure that they were accurate.
Attachment A provides a more detailed summary of our major efforts in the investigation.
At our meeting with you on September 17, 1980, we committed to some additional actions to identify any future leaks should they occur.
Attachment B describes the results of these additional actions as of the end of October, 1980. Many of these actions are continuing and the final results are not expected until January, 1981.
As these results become available, we will review them with our onsite resident NRC inspectors.
Sincerely, D.
. Scott Sta*. ion Superintendent Dresden Nuclear Power Station DJS/ DAA/jrh Attachments cc:
C. Reed F. Palmer D. Farrar R. Ragan T. Tongue D. Adam
I.
ATTACIDIENT A-I mESDEN STATION WATER IWENTORY IWESTIGATION CHRONOLOGICAL LISTING OF EVENTS 8-8 s
1.
Hydro-test of HPCI Test Return Ifne (no leaks).
8-12 1.
Walkdown of plant systems by Rad Waste Engineer. (no abnonnalities).
2.
Walkdown of plant systems by Tech Staff (no abnomalities).
8-15 1.
Walkdown of stonn sewer by Tech staff (no abnonnalities).
8 21 1.
Test of 2/3 B condensate storage tank with HPCI suction line valved in (level drop).
2.
Sampled stonn sewer by 2/3 bunker "C" oil storage tank (191 pci/L)
(290pci/L).
8-22 1.
Sampled sewer North of 2/3 boiler house (Bkgd).
2.
Sampled sewer SW of floor drain surge tank (Bkgd).
3.
, Sampled Ower South of oil separater pit (13 pci/L).
~
8-23 1.
Leak check of 2/3 A condensate storage tank with HPCI suction line valved in (level drop).
8-24 1.
Leak check of 2/3 B condensate storage tank with HPCI suction line valved in (no level drop).
1 8-28 1.
Operations walkdown of plant systens, sewers and miscellaneous plant support buildings (no abnomalities).
2.
Samples:
Manhole SE of I.M. calibration facility (11 pei/L).
a.
b.
Manhole in D1 trackway (13 pci/L).
I of 6
L.
)
Dresden Station Vater Inventory Investigation (cont'd) c.
Valve pit under 2/3. B condensate storage tank (41 pci/L).
d.
Discharge into D1 intake canal (30 pci/L).
e.
Manhob West of D1 B condensate storage tank (253 pci/L) (355 pci/L).
8-29 1.
Samples:
a.
Manhole by oil separator pit (211 pci/L).
b.
Drain pipe by 2/3 screenwash (12 pci/L).
c.
Manhole by 2/3 feed pump vent and exhaust (Bkgd).
d.
Manhole by D1 B condensate storage (191 pci/L).
e.
Waste Water Treatment Facility grab sample (23 pci/L).
f.
Sewage treatment plant (44 pci/L).
g.
Manhole by 2/3 oil sep. pit (263 pci/L) 278 pci/L).
h.
Manhole by D1 B condensate storage (288 pci/L) (274 pci/L).
i.
Fire protection at D2 Iso. Cond. (30 pci/L).
J.
Fire protection at D3 Iso. Cond. (24 pci/L).
E.
Drinking fountain in Admin. Building (52 pci/L).
1.
Drinking fountain in Access Control Building (32 pci/L).
9-2 1.
Walkdown of 2/3 Rx. Bldg. contaminated demin water system by Tech Staff (no abnomalities).
2.
Commenced tabulation of tank levels.
9-3 1.
Walkdown of Unit 1 contaminated demin, water system by Tech Staff (no abnomalities).
1 2.
Collected data on Torus and Fuel Pool make-up (excessive make-up to Unit 2 Torus).
l l
2 of 6 l
t i
)
Dresden Station Water Inventory Investigation (cont'd) 9-4 1.
Canmenced formulation of improved water balance program.
2.
Commenced shift by shift water logging and balance.
3.
Commenced UT flow checks:
a.
Unit 3 condensate transfer system to condensate demins (no a bno rmalities).
b.
Unit 3 condensate transfer system to Rx. Bldg. (no abnormalities).
4.
Checked 2B LPCI Hx (
1gpmleakage).
5.
Isolated 28 LPCI Hx. at 220Dhrs.
9-5 1.
Checked 2A, 3A, 3B LPCI Hx for leaks (none found).
5.
Installed level recorders on 2/3 A&B CST's.
3.
Isolated Unit 1 water system from Unit 2/3 water system.
4.
UT flow checks:
a.
Unit 2 CRD flow (no abnonnalities).
b.
Unit 2 condensate transfer system and jockey pumps (no abnormali ties).
5.
Completed tabulation of tank levels (no significant trending observed).
9-6 1.
Leak check of 2/3 A condensate storage and Unit 2 LPCI (no level drop).
2.
Ventilation humidity check (12.42 gpm evaporation).
3.
Began calibration of storage tank level instruments.
4.
Oper. Dept. began search for stean leak identification and tabulation.
5.
Checked all cross-ties between clean and contaninated jemin. water systems (no abnormalities).
3 of 6 f
r 1
t
')
f.
fresden Station Water Inventory Investigation (cont'd)
O 6.
UT flow checks, Unit 2 (no abnonnalities):
a.
Make-up pumps.
b.
Unit 2 Rx Building.
c.
Condensate transfer system to condensate demins.
d.
Nonnal make-up.
7.
. Began comprehensive logging of tank level before and after transfer and any operation requiring water.
9-7 1.
Ventilation humidity check (12.71 gpm evaporation).
2.
Continued logging leaks and storage tank calibration.
3.
LIT flow checks (no abnonnalities):
a.
Unit 3 condensate transfer and jockey punps.
b.
Unit 3 make-up pumps.
c.
Unit 2 condensate reject piping.
d.
Unit 2 CRD suction.
- e.
Unit 2/3 isolation condenser (condensate transfer, fire main, clean demin.)
f.
Unit 2 nonnal make-up.
9-8 1.
Ventilation humidity check at 1400 hr. (12.42 gpm evaporation).
2.
Conmenced evaluation of tank levels.
3.
Completed calibration of level instruments (significant number of instru. out of cal.).
4.
Marked up P&ID's of all systens checked (refer to attached).
9-9 1.
Secured taking humidity checks on ventilation.
4 of 6
y t
)
Dresden Station Water Inventory Investigation (cont'd) 2.
Checked flow measuring instruments for Units 2 & 3 CRD and con-densate reject.
3.
Perfonn UT flow checks of Units 2 & 3 CRD and Condensate Reject piping.
i The following itens still in progress:
1.
Development of improved water inventory program.
2.
f! arch for steam leaks.
3.
Check drains for water and sample.
4.
UT flow check of misc. piping.
5.
Logging tank levels before and after transfers.
6.
Logging any operation that involves water transfer.
7.
Sample plant effluent system as per surveillance schedule.
8.
Walkdown of plant systems.
9.
Up date P&ID's when systems are checked.
NOTE:
Not all walkdowns are logged.
Only those of long duration or specific systens were logged.
List of P&ID's Marked Up M,-35-1 (M-366) Well Water Piping M-27 (M-358) Core Spray Piping M-28 (M-359) Isolation Condenser Piping M-29-1 (M-360) LPCI Coolant Injection Piping M-51 (374) HP Coolant Injection Piping M-269 (529) Reactor Building Ventilation M-270 (530) Turbine Building Ventilation M-375 Screen Wash and Fire Protection Piping 5 of 6
7--
7-t kesden Station..ater Iny:ntory Innstigation (writ'd)
Effluent Samples of Non-Radioactive Systens Sample Frequency
~
DI Energency Condenser Monthly D2 Isolation Condenser Monthly D3 Isolation Condenser Monthly Well Water Monthly Sanitary Waste Monthly 2/3 Cribhouse Sunp Monthly Maste Water Treatment Monthly Domestic Water Monthly Di Circ Water Discharge Daily 2/3 Circ Discharge Daily Sphere Service Water Discharge Daily Heating Boiler and Deaerator 3 times / week 01 Storage 3 times /wek Closed Cooling Water Systems 3 times /..eek CCSI When requested for operation.
9 e
6 6 of 6 p.
I ATTACHMENT B FURTHER ACTIONS IN THE WATER LEAKAGE INVESTIGATION AT DRESDEN STATION (FALL, 1980)
Water Inventory Systems The existing water inventory program has been continued. This method includes calculation of water inventory in twenty-five radwaste and condensate storage tanks and plots of the results to identify trends.
Additionally, known additions to this inventory, such as clean demineralized water additions to the contaminated condensate storage water tanks, are more closely monitored to note if excessive water is being used and the volume of these additions are noted on the data plot.
Even after taking into account these additions, this inventory continues to indicate an apparent average water loss of about 8600 gallons per day. As you know, this inventory does not take into account water lost through the plant ventilation system, nor inputs to the system from seepage, heating system condensate leakage, and other non-contaminated inputs such as laundry water.
The station has initiated, for trial use, a more comprehensive inventory of water stored on site.
This weekly inventory has shown similar results as our existing inventory system.
It also does not take into account evapora-tive losses nor most non-contaminated inputs to the system. The station will continue to investigate and upgrade our water inventory programs. By January 1, 1981, when the full magnitude of evaporative losses are known, a new inventory system will be developed and implemented.
Evaporative Water Losses The station has contracted Science Application Inc. (SAI) to measure water vapor releases in ventilation system exhaust air from Units 2 and 3.
The technique used is to measure tritium release rates in exhaust air from each turbine building and each reactor building. Water vapor release rates are determined by dividing tritium release rates by the tritium concentra-tion in reactor coolant.
Two sets of weekly measurements have been collected and analyzed, using previous determinations of tritium concentration in reactor coolant, to provide a preliminary estimate of evaporative losses:
Sample Collection Dates 9-30 to 10-7 10-7 to 10-15 Unit 2 Reactor Building (gpm) 2.1 2.3 Unit 3 Reactor Building (gpm) 1.2 1.5 Unit 2 Turbine Building (gpm) 14.5 6.8 Unit 3 Turbine Building (gpm) 10.6 11.0 20.4 21.6
~-
~
F,.
i These initial results indicate that water loss through the plant ventila-
~
tion system can account for the apparent loss noted in our water inventory program.
Further measurements will be taken to accurately identify evaporative losses. Also, SAI will analyze tritium concentrations in fuel storage pools, reactor coolant, and condensate and verify actual ventilation system exhaust flows. This work should be completed by January 1, 1981.
System Configuration Verification The station has completed a walkdown of systems to identify potential leak paths, points at which water could be released by a sabateur,configura-tions which differ from existing documentation, and other conditions which might be significant.
This effort has not located any indications of sabotage nor leakage of contaminated water to clean systems.
All service water, con-tainment cooling service water, emergency diesel cooling water, clean deminerali-zed water and domestic water systems for Units 1, 2, and 3 have been investigated.
A review and investigation of the domestic water and clean demineralized water piping has shown that it would be extremely difficult for any individual to introduce contaminated water into these systems.
There is no open pathway into which contaminated water could travel unless an additional drain were lef t open.
This water would drain and be reclaimed in the liquid radwaste system or be discharged via the sewage or waste water treatment systems.
The sewage treatment and waste water treatment systems effluent are routinely analyzed for radioactive contaminants.
Thus, releases via these pathways would be identified. No further action on domestic water and clean demineralized water systems is warranted, except for training of personnel which will be addressed later in this report.
Investigation and review of the service water, containment cooling service water, and emergency diesel cooling water systems has shown that there are approximately 200 vents and drains on related piping and equipment throughout the station. To determine the points for release of contaminated water through these systems by inadvertant action or sabotage, we have set a criteria of no more than 50 feet (one length of hose), between the contamir.ated water source and the non-contaminated system vent or drain. No review was made to confirm that the necessary pressure differential existed between the two systems to make such a transfer possible.
Had that review been made, we feel that the list of possible release points would have teen smaller. Using our criteria, we have identified 52 locations on Units 2 and 3 and 15 on Unit 1.
In order to monitor these potential release locations, a copper wire valve seal has been attached to the I
valve on each of these vents and drains in such a manner that they cannot be opened without breaking the seal. A monthly valve seal surveillance has been incorporated into the operating routines to check the integrity of seals.
Identification tags have also been placed on each valve to inform personnel that i
4
7 j
4
-they must contact the Shift Engineer and receive permission prior te breaking the. valve. seal. The Shift Engineer is responsible for seal replacement.
Broken seals found during the monthly surveillance will be reported to the Operating Engineer forcinvestigation.
Training of operating personnel on the surveillance program and in their responsibilities in. identifying potential sabotage or inadvertant release will be completed by January 1, 1981.
.Well Sampling Program In light of the preliminary data on evaporation losses, the station at this tima does not believe that drilling an additional well on site is warranted.
But, the station has initiated routine sampling by by our en-
.vironmental contractor of the well located at the Dresden Lock and Dam and at three local residential sites.
Heat Exchanger Leakage The station has initiated a new Tech Staff procedure (DTS 1500-2)
. to leak test LPCI Heat Exchanger tubes for potential leakage on a monthly baeis.
This item has also been ado.ed to the Tech Staff surveillance pro-gram to assure monthly test performance. Thus far, no tube leaks have been detected.
Construction Activities
. The station through the Station Construction Department closely monitors the activities of construction crews on site. Edison Station Construction Forenen are assigned to oversee constructor personnel and assure that their activities are in compliance with station procedures.
.