IR 05000250/1979027
| ML17339A271 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 09/21/1979 |
| From: | Gibson A, Zavadoski R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML17339A265 | List: |
| References | |
| 50-250-79-27, 50-251-79-27, NUDOCS 7911150101 | |
| Download: ML17339A271 (11) | |
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UNITEDSTATES NUCLEAR REGULATORYCOMMISSION
REGION II
101 MARIETTAST., N.W., SUITE 3100 ATLANTA,GEORGIA 30303 Report Nos. 50-250/79-27 and 50-251/79-27 Iicensee:
Florida Power and Light Company 9250 West Flagler Street Miami, Florida 33101 Facility Name:
Turkey Point Unit 3 and
Docket Nos.
50-250 and 50-251 Iicense Nos.
DPR-31 and DPR-41 Inspection at:
Turkey Point site ar Homestead, Florida e
Inspector:
U3 R.
W. Zav s
9z/7
. F.
Gobs n, Sects,on Chx.ef, Q
8UMHARY Inspection on August 29-31, 1979 Areas Inspected Approved By:
A FFMS B h
Date Signed This special unannounced inspection involved 18 inspector-hours onsite in the areas of the overflow of the Unit j/4 spent fuel pool and resultant radiological considerations.
Results Of the one area inspected, three apparent items of noncompliance were found.
(Failure to follow procedures, paragraph 4.c; radiation levels in an unrestricted area, paragraph 5.C; and unauthorized burial of radioactive material, paragraph 5.d.)
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DETAILS 1.
Persons Contacted Licensee Employees E. Yaeger, Plant Manager K. Hays, Plant Superintendent, Nuclear W. Hughes, Health Physics Supervisor S.
Wade Jr., Chemistry Supervisor S. Peck, Health Physics Administrative Supervisor Bates, Health Physics Special Assistant Brown, Health Physics Other licensee employees contacted included two construction craftsmen, eight technicians, and three operators.
-Attended exit interview 2.
Exit Interview The inspection scope and findings were summarized on August 31, 1979, with those persons indicated in Paragraph 1 above.
The inspector summarized the scope of the inspection including the items of noncompliance concerning failure to follow written procedures (Paragraph 4.C), radiations levels in an unrestricted areas (paragraph 5.C) and unanuthorized burial of radioactive material(paragragraph 5.d).
The plant manager acknowledged the items of noncompliance.
3.
Description of Spent Fuel Pool Overflow On August 28, 1979 at approximately 3:10 p.m., the Unit
$/4 Spent Fuel Pool (SFP)
overflowed.
Licensee representatives estimate 3,000 gallons of SFP water was released to the restricted area.
Of this 3,000 gallons, they futher estimated that 20 gallons found its way to a storm drain, designated C.B. g5, which flows to a dry well located outside the restricted area.
Samples taken just prior to the liquid entering the storm drain showed concentrations of Co-60 (3.2 x 10
~ Ci/ml), of Co-58 (6.0 x 10 s Ci/ml) and of,Co-57(4.2 x 10 s Ci/ml).
In all, approximately three millicuries was released to storm drain, 2.4 millicuries of which was Co-60.
The overflow was terminated by 3:15 p.m.
and the overflowed liquid was contained by 3:20 p
m ~
4.
Status Prior To Overflow a.
SFP High Level Alarm From discussions with licensee representatives and direct observation, the inspector found that the high level alarm on the Unit j/4 SFP was in an activated state from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> preceeding the overflow to at
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"2-least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the overflow.
The high level alarm is activated when the level in the SFP comes within eight inches of the top of the pool, but cannot be reset until the level is within eleven and one half inches of the top.
The level in the SFP is verifieg visually and recorded on log sheets by operators at 1:00, 5:00, and 9:00 a.m.
and 1:00, 5:00, and 9:00 p.m.
each day.
Prior to the overflow at 1:10 p.m.
on the 28th, the level in the SFP for Unit JI4 had been verified by the operators.
b.
Recirculation of RWT Prior to the overflow, the Refueling Water Storage Tank (RWST) (335,000 gallons capacity)
was being cycled through the Spent Fuel Pool Deminera-lizer (SFPD) to clean up the water in the RWST.
This action requires that valves 802A and 805A be open.
Recirculating the RWST through the Spent Fuel Pool Demineralizer is a normal operating procedure, and if executed properly, willnot add to the volume of the Spent Fuel Pool.
Co Lineup of the SFP with the SFPD At approximately 1:00 p.m. on August 28, 1979, an operator was instructed to align the Spent Fuel Pool with the Spent Fuel Pool Demineralizer.
From discussions with licensee's representatives, the inspector ascer-tained that the operator reviewed flow diagram number E-4515, "Sampling System and Spent Fuel Pit Cooling System",
and aligned the system to commence SFP cleaning.
The operator was unaware that Operating Procedure 3500.1 entitled "Spent Fuel Pit Cooling System Normal Operation" covered the operation that was being performed.
Section 8.2 of Operating Procedure 3500.1, addresses the required alignment for SFP purification and speci-fically requires that valves 802A (RWST to SFP) and 805A (SFP to RWST/CVCS)
be closed.
Had the procedure been followed, the simultaneous operation of the RWST through the SFPD, and operation of the SFP through the SFPD, and subsequent overflow of the SFP would have been avoided.
The inspector informed licensee representatives that failure to follow Operating Procedure 3500.1 was an item of noncompliance (79-27-01).
The inspector also noted that two hours transpired between the alignment of the SFP to the SFPD and the actual overflow.
The inspector had no further questions or observations in this area.
5.
Determinations. After The Overflow a ~
ActivityReleased From the SFP The activity released to the storm drain was ascertained by obtaining a sample of the liquid in the vicinity of the storm drain, as previously discussed in paragraph 1.
To determine the activity released from the SFP to the restricted area samples from the SFP are necessary.
Unfortunately, a sample was not taken at the time of the overflow.
The inspector reviewed the results of the latest available sample (obtained on August 23, 1979) and requested that licensee representatives obtain updated samples of the SFP and RWST.
The results of these samples are tabulated belo "3" CONCENTRATION (pCi/ml)
~Ieoto e
Co-60 Co-58 Co-57 Unit /f4 SFP (8/23)
8.04K10 1.64X10 1.21X10 Unit JI4 SFP (8/30)
8.76X10 1.60X10 1.09X10 Unit $/4 RWST (8/30)
2.4X10 1.2X10 Cs-137 1.4X10-Based on the above number, the loss of 3,000 gallons of SFP water represents a loss of 1.1 to 1.2 curies total activity from the spent fuel pool.
This calculation conservatively overestimates the loss because at the time of the overflow the addition of RWST water, which is much lower in concentration, was being made to the top of the SFP.
The concentration of liquid released from the SFP, based on the average of the August 23 and 30 samples, represent approximately 1850 times the unrestricted area water Maximum Permissible Concentration (MPC)
for an unsoluable chemical form and 2900 times MPC for a soluable chemical form as specified in 10 CFR 20 Appendix B.
b.
Direct Radiation Surveys Inside the RCA c ~
Accompanied by licensee representatives, the inspector toured the area inside the radiation controlled area (RCA) affected by the overflow.
The inspector found that the outside west wall of the SFP Building had surface radiation readings of 30 to 50 millirem/hr.
The concrete walkway and gravel adjacent to the west wall also were reading 30 to 50 millirem/hour.
The passage way between the SFP Building,and the Radwaste Building had surface radiation readings on the south side of the SFP Building of 20 to 30 millirem/hour.
The concrete walkway and gravel adjacent to the SFP Building-were about the same.
The total ground area of concrete and gravel affected by the overflow was esti-mated by the inspector to be approximately 1500 square feet.
The inspector had no further questions or observations in this area.
Dry Well Twenty gallons of the SFP overflow eventually reached a storm drain, designated C.B./j5.
This storm drain, located in the RCA or restricted area, flows to a dry well (a subterranean gravel filled drainage field approximately ten feet long by ten feet wide by ten feet deep) located outside the restricted area, but within the protected area.
The inspector requested that the exact location of the dry well be pointed out.
Accompanied by licensee representatives the inspector surveyed the surface of the dry well and found the general area around the dry well to be 0.1 millirem/hour.
One area surveyed, approximately
foot square had geppral area radiatjpp levels of 0.2 gp 0,3 g)iffirem/
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hour.
Samples from the surface soil near a 0.8 millirem/hour hot spot showed that Cobalt-60, Cobalt-58 and Cesium-137 were present.
A quantitative assessment was not possible because the licensee's isotopic identification system (GeLi Detector)
was not calibrated to measure soil samples.
The inspector noted that cesium was not detected in the SFP samples of August 23 and 30.
Additional surveys by licensee representatives on August 30, 1979, in the vicinity of the dry well identified one area approximately two feet in diameter and one foot deep at the base of the, dike where radiation levels of 5 millirem/hour were obtained.
This radiation field had been present for a period greater than an hour.
Excavating the hole an additional one to two feet deeper yielded radiation levels of 30 millirem/hour.
At the bottom of the hole the inspector observed a small stream of water mixed with an oily substance.
A 500 milliliter sample of the mixture identified Cobalt-60 and Cobalt-58 present in concentrations of 1.4X10 pCi/ml and 2.8X10 pCi/ml, respectively.
Additional soil samples taken by licensee representatives from the dry well area identified two more isotopes, Manganese-54 and Cesium-134.
The predominate isotope for all samples taken was Cobalt-60.
The inspector informed licensee representatives that the presence of an unknown and unsurveyed 5 millirem/hour radiation field outside the radiation control area was an item of noncompliance (79-27-02)
and was contrary to the provisions of 10 CFR 20.105(b)(1).
Estimate of Activityin Dry Well The inspector asked licensee representatives for an estimate of the total activity contained in the dry well.
Licensee representatives stated that they had not made an estimate of the total activity in the dry well.
The inspector made two crude estimates of the activity
'ontained in the dry well.
The first estimate assumes that the affected volume. was 25 foot long by 20 feet wide by 8 feet deep (volume of 4,000 cubic feet),
a density of 2 grams/cubic centimeter for crushed gravel and a Cobalt-60 concentration ranging from 10 4 pCi/gram to 10
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pCi/gram.
This estimate, leads to the conclusion that there is from 20 millicuries to 2 curies of Cobalt-60 contained near and at the dry well.
The concentrations used for Cobalt-60 are based on the isotopic analysis of gravel done by licensee representatives.
Since the licensee's equipment was not calibrated for gravel samples and gravel is denser than water, the estimates are probably low.
A second estimate was made by the inspector based on observed radiation levels and shielding calculations assuming a uniform disk source of twenty foot diameter located one half to one foot below the sand surface and a surface reading of 0.3 millirem/hr, the activity in the hypothetical disk is calculated to be approximately 150 millicuries to 4 curies of Cobalt-60 for a half foot and one foot burial, respectively.
This calculation assumes the surface is not contaminated, which is not the case.
In spite of the inadequacies of the above estimates, the
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total Cobalt-60 activity contained in the dry well probably lies within the bounds of 20 millicuries to 4 curies.
In addition, as described in paragraph 1, approximately 2.4 millicuries of Cobalt-60 were released by the present overflow to the storm drain system which empties into the dry well.
Based on the evidence at hand, there is more than one millicurie of Cobalt -60 buried in the dry well.
The inspector informed licensee representatives that the resultant burial of more than one millicurie of Cobalt-60 in the soil by the overflow of the spent fuel pool was contrary to the provisions of
CFR 20.304(a)
and was an item of noncompliance (79-27-03).
6.
Storm Drain System The storm drain system at Turkey Point has three main branches.
One branch empties into the dry well already described in Paragraph 3.c.
Of the other two branches, one discharges into the intake canal and the other into the discharge canal.
The inspector requested that, as a precaution, samples be taken in the storm drains in the branches not sampled.
Each storm drain sampled (9 in all) contained near or above levels of unrestricted area MPC's for Cobalt-60.
This is an open item pending resolution of the source and quantity of the release (79-27-04).
Immediate Action Ietters a ~
During the inspection, an immediate action letter was issued by Region II concerning the operational, procedural and instrumentation actions the licensee will take to avoid a future spent fuel pool overflow or other inadvertant discharge.
The actions the licensee representatives agreed to were discussed via telephone on August 30, 1979 and sent via letter on August 31, 1979.
b.
Following this inspection, an additional immediate action letter was sent on September 5,
'1979, and confirmed additional steps that would be taken by licensee representative to account for unmonitored radio-active liquid discharges, remove or evaluate the contaminated dry well and identify the source of activity in the storm drain syste e
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ATTACHh)ENT Re:
RII:RVL 50-250/79-26 50-251/79-26 FINDING B:
As required by Section 6.9.2.b.3 of the Technical Specifications, observed inadequacies in the implementation of administrative or procedural controls which threaten to cause reduction of degree of redundancy provided in reactor protection systems or engineered safety feature systems shall be reported to the NRC.
Contrary to the above, the lack of proper control and documentation of the bracket fabrication and installation process on the emergency diesel generator as discussed in the June 8, 1979, Plant Nuclear Safety Committee minutes was not reported to the NRC.
RESPONSE B:
Review of the circumstances associated with the fabrication and installation of a mounting bracket for a replacement excitation transformer on the
"A" emergency diesel generator had revealed deficiencies in the control and documentation of the work.
As indicated i n the finding, these deficiencies were documented and reviewed by the Plant Nuclear Safety Committee.
At that time the judgment of the responsible individuals did not determine the item to be reportable because the strength or functional adequacy of the bracket was not in question.
Subsequent difficulties in resolving these documentation problems ultimately resulted in alteration of the transformer mounting fasteners to obviate the need for the bracket even though there was no concern regarding capability of the bracket to perform its intended function.
At this point the item was under active review by the NRC inspector and reportability was, in-advertently, not reconsidered at that time.
Hanagement actions to ensure strict compliance with procedures coupled with revision of administrative controls to require prior g.
C. review of safety related maintenance work plans are referenced as treatment of the root cause of this problem.