ML061000449
| ML061000449 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 11/10/2005 |
| From: | Inside Entergy - Indian Point News |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| FOIA/PA-2006-0081 | |
| Download: ML061000449 (2) | |
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- ;nd1ian, Point News November 10, 2005 Spent Fuel Pool Bulletin Liner Inspection and New Wells Aid SFP Investigation No leak found duringvacuum box test A diver from Underwater Construction, a company in Essex Connecticut that specializes in nuclear dive services, performed an underwater inspection of the southwest corner of the IP2 svent fuel pool on Tuesday evening. He installed a vacuum box around two of three potential flaws found in a video inspection of the pool liner. Vacuum box tests are used for rapid leak detection of weld seams. The diver can use an observation window in the box to look for water coming through the flaws and monitor the drop in vacuum that could indicate a small leak in the weld. From the preliminary results of the vacuum box test on Tuesday, there did IP2 spentfuel pool. The empty areain the not appear to be any through wall leaks.
upper left handcornerof the fuel racks is the cask loading Iay areawhere the vacuum box The video inspection of the spent fuel pool liner, which is about test was performed. 40% completed, showed three small areas along the southwest corner of the pool that had what appeared to be weld anomalies.
Pictures showed a discolored trailing from the flaw.
The spent fuel pool dive was conducted as an Infrequently Performed Test or Evolution with a number of safeguards in place to prevent overexposure of the diver. During the ALARA brief,
.~ Bob Deschamps who served as senior manager on the job, emphasized the need for a safe working environment for the diver.
"Even slight movements away from the work envelope can result in significant dose to the individual," he noted. Industry Operating Experience has shown that radiation fields can change dramatically when diving within several feet of spent fuel elements. As part of the work plan, an underwater radiatio l survey was performed on the lowest of the three flaws in anticipation of a test in the area nearest the spent fuel assemblies.
The survey results show is it safe to dive in that area.
The diver's movement was limited by the dive basket or cage. He was also tethered by an "umbilical" cord which limited the depth he could go in the pool. The dive supervisor, Richard Anthes and the lead health physics technician, Lloyd Frank, had the diver under constant view with remote cameras to ensure the diver remained within the survey area. The diver also wore whole body l11 01 Ad.dosimetry on his back, arms and legs that was monitored remotely to ensure dose limits would not be exceeded. The diver received Diver cautiou.ly descends ladder into cask an estimated 10-15 millirem of exposure about the same as a loading areaefIP2 spentfuelpool. typical bone X-ray. The entire team received just 25 millir-.
A single fuel element can create dose fields in excess of 10,000 Rem/hr.
All equipment including the dive suits, air supply, dive basket, air compressor and remote monitoring telemetry were checked just prior to the dive. As a precaution, the crane and hoist controls were locked in place to prevent movement outside the safe zone.
"I want to commend the team that performed this evolution," said Site Vice President Fred Dacimo. "It was well planned, well executed with a serious focus on safety as job one."
- Water Sampling Programs Gets Nevw Ray Fucheck, radiationprotection Wells supervisor, waS in constant communication Well drilling rigs are on site this week to install new monitoring with dive teamr and remote monitors. Lou wells as part of the continuing investigation into the small leak in kenoscal, who helped coordinatethe overall IP2 spent fuel pool. The first well is being drilled in the loading evolution, is behindRay. bay area of the fuel storage building. Eight additional wells at five sample locations will be installed in this phase of the investigation. Technicians continue to sample the existing wells.
Sample results are consistent with environmental conditions and previous samples obtained and reported in mid October. Testing results for Strontium-90, a fission product found in spent fuel pool water, from MW-I I I was negative. Monitoring W\ell-l 11 is located in the IP2 transformer yard about 150 yards from the spent id fuel building. It is the only well on site found to have levels of tritium above drinking water standards in the last round of test results.
Testing was conducted on the two nearest public drinking water supplies and a sample well in Verplanck. All three tested negative for radioactivity above background levels. This is no hazard to Diver in spent fuel pool. The vacuum box is workers or the public from the leak at IP2.
directly in front of him in the southwest
'cornerof the pool. The suction cups on The site is continuing to work with hydrology experts to be tter
,eitherside ofihe wall are to prevent I i define groundwater movement on the site. The next series of wells movement of tie basket anddiver outside the survey area.
will help refine the ground water model.
The Nuclear Regulator Commission is also continuing its special inspection and overseeing the tests that Entergy conducts.