ML20235U957
| ML20235U957 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 02/03/1989 |
| From: | Bird R BOSTON EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20235U946 | List: |
| References | |
| BECO-89-12, NUDOCS 8903090447 | |
| Download: ML20235U957 (6) | |
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sosxwswson Pilgrim Nuclear Pcr.ver station Rocky Hill Road Plymouth, Massachusetts 02360 Ralph G. Bird Seni rVice President-Nuclear f 0bruary 3,1989 BECo Ltr 03-12 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Hashington, D.C.
20555 Docket No. 50-293 License No. DPR-35 Sut' ject:
NRC Inspection Report 50-293/88-35
Dear Sir:
Attached is Boston Edison Company's response to the Notice of Violation contained in the subject inspection report.
i Please do not hesitate to contact me directly if you have any questions.
BNd' BPL/dmc l
Attachment:
Response to Violation 88-35-02 l-cc: Mr. Hilliam Russell Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Rd.
King of Prussia, PA 19406 l
Sr. Resident Inspector - Pilgrim Station 1
8903090447 890302 PLR ADOCK 05000293 Q
4, Attachment Response to Not.ce of Violation (88-35-02)
Boston Edison Company Docket No. 50-293 Pilgrim Nuclear Power Station License No. DPR-35 NRC Notice of Violation As a result of the inspection conducted on November 28 to December 2, 1988, and in accordance with the ' General Statement of Policy and Procedure for NRC Enforcement Actions," 10 CFR Part 2, Appendix C (Enforcement Policy)(1986),
the following violation was identified:
10 CFR 50.59 allows, in part, the licensee to make changes to facilities or procedures described in the Safety Analysis Report provided that no unreviewed safety question is involved. The Pilgrim Station solid radwaste systems are described in PNPS-FSAR section 9.3.
Contrary to the above, on November 16, 1988 operations were conducted in the Process Building trucklock that were not in accordance with the FSAR and without an appropriate safety evaluation.
Boston Edison Comoany Resoonse Event
Description:
On November 16, 1988 at approximately 0945 hours0.0109 days <br />0.263 hours <br />0.00156 weeks <br />3.595725e-4 months <br /> a Nuclear Plant Operator observed water flowing in rivulets from under the Radwaste Trucklock (RWTL) truck access door to the adjacent paved plant yard area.
By approximately 0950 hours0.011 days <br />0.264 hours <br />0.00157 weeks <br />3.61475e-4 months <br />, the Control Room had been notified of the event, and a contractor waste processing technician had entered the RWTL and secured the source of the spill.
The spill resulted from operations in the RHTL involving the transfer of diatomaceous earth (DE) from the collection cask to a cask containing a dewatering filter. The transfer involved adding water to the DE collection cask to make a slurry of DE and water and pumping the slurry to the filtering cask. When the filtering cask is sufficiently filled, a dewatering pump is l
started to extract the filtered water. The slurry-fill-dewatering operation l
is repeated until the DE cask is emptied and the filtering cask has been
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dewatered to less than one percent water by volume.
l On November 16, the transfer of slurry to the filtering cask had been secured l
to allow the cask dewatering to reduce the liquid level of the cask. At approximately 0840 hours0.00972 days <br />0.233 hours <br />0.00139 weeks <br />3.1962e-4 months <br /> the two contractor waste processing technicians exited the RHTL with dewatering in progress to minimize their radiation dose.
Prior to exiting, a technician checked the water supply valve and it appeared The water supply valve was actually open. With the slurry transfer closed.
secured, the water filled the DE cask then overflowed onto the RHTL floor and ultimately to the adjacent plant yard area.
The maximum leakage from the 1 inch demineralized water hose was estimated at 2660 gallons. Approximately 200 gallons of contaminated water is estimated to have flowed from the RWTL to the adjacent plant yard area.
The remainder of the water was retained within the RWTL and the Radwaste Building.
Approximately 3000 square feet of pavement and 600 cubic feet of sand and gravel were contaminated.
The spill was contained within the restricted area boundary.
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e, Attachment (Continued)
Cause:
The spill was caused by the failure to close the water supply 4.alve to the DE cask. The root cause for the failure to close the valve was a lack of procedural controls. Although a procedure existed for cask dewatering in the RHTL, the procedure did not address the transfer of slurried material from one cask to another. The condition of the water supply valves also contributed to the spill.
Due to a valve packing leak, the water supply valve had.been l
opened tight on the backseat. A technician checked the water supply valve prior to exiting the RHTL, but, believed the valve had been previously closed. Therefore, when normal operating force was applied, no valve movement confirmed to the technician that the valve was closed.
The following additional problems were recognized by the investigation of the event.
Although transfer of spent resin to the RWTL in preparation for shipment is described in the Final Safety Analysis Report (FSAR), the FSAR does act describe the cask devatering/DE slurry transfer operation in the RWTL. A safety evaluation per 10CFR 50.59 was not prepared to show that the deviation from the FSAR did not constitute an unreviewed safety question.
Safety Evaluations #1442 and #1469 were prepared in 1982 to allow the temporary transfer of sludge to the RHTL for dewatering; however, the Safety Evaluations expired after one year of operations.
The RHTL floor drains are blocked.
If the floor drains were clear, the spill may have been limited to the RHTL.
There was no containment device (dam or berm) in place to contain a spill. A berm had been placed outside of the RWTL to contain any spills of radioactive liquid or filtering material within the restricted area. The berm had been removed in 1985 during excavations in support of plant construction activities.
Initial Corrective Actions Taken:
By approximately 0950 hours0.011 days <br />0.264 hours <br />0.00157 weeks <br />3.61475e-4 months <br />, the Control Room had been notified of the event and a contractor waste processing technician had entered I
the RHTL and secured the source of the spill.
Samples were collected end anal ped to determine the extent af the spill.
Detectable concentrations of Cs-137, Co-60 and Mn-54 were identified. Samples of standing water in the plant yard showed an activity concentration in the order of SE-3 microcuries per cubic centimeter (uci/CC). Samples from the area adjacent to the inner security fence showed an activity concentration in the order of 5 E-4 uti/CC. Samples from the area outside the protected area boundary showed less than the minimum detectable activities.
Decontamination had begun by approximately 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> on 11/16/88.
The loose surface contamination was removed from the paved yard area using hepa filtered vacuums followed by a steam cleaning vacuum and was completed on 11/17/88. The remaining fixed contamination on the pavement was treated with a tar-based sealant on 11/19/88.
Approximately 600 cubic feet of contaminated sand and gravel was excavated from the area adjacent to the inner security fence, put in containers and replaced with clean compactable material.
The spilled I
water that remained in the RHTL was pumped to the radwaste sump on I
11/16/88. The RHTL was decontaminated to normal operational levels on 11/17/88.
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Attachment (Continued)
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A critique of the event was conducted at 1130 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.29965e-4 months <br /> on 11/16/88. At that time,.all processing operations in the RHTL were ordered stopped until a review of RHTL processes was conducted and appropriate corrective actions taken.
Short Term Corrective Action Taken:
'A 10CFR 50.59 Safety Evaluation (S.E.) No. 2338 for' processes conducted in the~RHTL was completed on.12/14/88.
The Safety Evaluation establishes the conditions-such'that an unreviewed safety question will.'not exist for processing in the RHTL. These conditions assure that a spill would be contained within the RWTL and the Radwaste Building even with the RWTL floor drains plugged and include:
a liquid barrier (berm) in the RHTL.
a RHTL. floor plug removed during processing.
I radwaste: collection casks in the RHTL will be continuously monitored during filling.
Temporary Modification (T.M.) 88-09 to install a liquid barrier (berm) in the RHTL was approved on 12/15/88. The berm will contain potential spillage from process operations within the RWTL to the RHTL and the Radioactive Haste Building. The T.M._is supported by S.E.
No. 88-36. The T.M. was installed under Maintenance Request (M.R.)'No. 88-56-172 and was completed on 12/17/88.
T.M. 88-10, approved on 12/16/88, documents the replacement of a hard-piped equipment drain from the RHTL to the Radwaste Building Floor Sump with a carbon steel pipe manifold and a 2" flexible hose.
The hose is required to have a minimum design operating pressure of 225 psi and to be rated for a temperature of 210' F or greater. The T.M. is supported by S.E. No. 2339. The T.M. was installed under MR No. 88-20-174 and was completed on 12/24/88.
The following Pilgrim procedures have been prepared to control radwaste processes in the RHTL.
Procedure No. 2.5.1.6, " Dewatering the Spent Resin Tank From the Radwaste Truck Lock" was approved on 12/16/88.
Procedure No. 2.5.1.1, " Sluice Diatomaceous Earth from Filter I
Freeliner to ECODEX Liner" was approved on 12/21/88.
Procedure No. 2.5.1.4 " Transferring Spent Resins to Shipping Containers" was approved on 1/6/89.
Procedure No. 2.5.1.5, " Dewatering of Spent Resin H.I.C.
Liners" was approved on 1/12/89.
Procedure No. 2.5.1.2 " Dewatering 14-215 or Smaller Liners containing Powdex Resin, Precoat material or D.E." was approved on 1/26/89.
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4 t Attachment (Continued)
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Corrective Actions Taken or Planned to Prevent Further Violations:
Plant Design Change (PDC) No. 88-49 has been initiated to
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permanentize the RHTL spill curbs (TM88-09) using concrete berms and structured steel angle guides. The PDC has been scheduled to be task
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ready on 2/17/89.
Radwaste processing formerly performed by contractor personnel under the Operations and Radiological Sections are now performed by Boston Edison personnel.
A position of Radioactive Haste Project Manager has been established and filled. The individual assigned to the position has been chartered to develop and implement a Radwaste Betterment Program.
Safety Consequences:
The event resulted in no added risk to the health and safety of the public as the spill was contained within the restricted area. However, had the spill gone unobserved for a duration longer than the event on 11/16/88, an uncontrolled release of liquid radioactive material to the unrestricted area may have resulted.
It is recognized that the consequences of an uncontrolled release are dependent upon the source term and duration.
For the event on 11/16/88 a contractor radwaste processing technician was preparing to reenter the RHTL when the spill was discovered.
Therefore, if the event had not been observed in the plant yard area, the technician would have entered the RHTL, observed and secured the spill at about the same time as the spill was actually secured.
Date of Full Compliance:
Full compliance was achieved on 11/16/88 when all processing operations in the RHTL were ordered stopped until a review of RHTL processes was conducted and appropriate corrective action taken.
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