There is one reactor core at Shearon Harris, but there are four pools for the used nuclear fuel-rod assemblies because, originally, there were going to be four reactors there. The pools are an obvious target for terrorists, and raise the prospect of a catastrophic disaster if destroyed (See "Hot Rods" Nov. 29, 2000). But CP&L has maintained the pools cannot be destroyed. Does Sept. 11 change that?
Moreover, CP&L is the only utility company in the country shipping nuclear wastes from one site to another. Because the waste storage pools are full at its nuclear plants in Southport and Hartsville, S.C., excess wastes are loaded into concrete casks and sent to Shearon Harris by rail car. Are the rail cars another potential terrorist target?
Doubtless CP&L, like all of us, is reconsidering its risk assessments and security needs in the light of Sept. 11. Problems that might have been dismissed as abstract or speculative before may be thought of now as all too real. They were real before Sept. 11 to the North Carolina Waste Awareness and Reduction Network, the environmental group that is the company's leading critic. N.C. WARN is currently holding meetings all over the region to pressure CP&L to shift away from pool-waste storage to dry-cask storage, which the group argues is safer, and to stop shipping Southport's and Hartsville's wastes to Shearon Harris.
The region's emergency management officials are also organizing a meeting after the New Year for the purpose of reviewing with CP&L officials questions raised by having a nuclear plant in our midst, including evacuation planning.
In anticipation of that session, we're sending some questions to CP&L that we'll ask the company to respond to in writing:
1. The four waste-storage pools at Shearon Harris are located in one building adjacent to the reactor core. The building is not fortified the same way as the core, which is surrounded by a thick "containment" dome. To what extent can it withstand an attack from the air or by bomb?
2. The nuclear fuel-rod assemblies stored in the pools are cooled by water, preventing any release of radiation. If the building were destroyed, what is the chance the pools would also be damaged so that they could no longer hold water?
3. If the pools do lose water as a result of an attack, what is CP&L's plan for retrieval and safe storage of the nuclear fuel-rod assemblies they hold?
4. How much radiation would be released if, as the result of water loss, the fuel-rod assemblies are exposed to air?
It's been the contention of Dr. Gordon Thompson, of the Institute for Resource and Security Studies in Cambridge, Mass., that if a waste pool loses water and the fuel-rod assemblies are exposed to air, the fact that utilities like CP&L have packed so many assemblies into them makes it likely that they would react with one another and a chain reaction would start--an exothermic nuclear reaction that would release radiation on the scale of the Chernobyl disaster.
Waste pools, Thompson argues, were designed only for temporary storage while used fuel rods were still at their hottest. The assumption, decades ago, was that nuclear wastes would be reprocessed and used again. Thus, a relatively small number of assemblies would be in a single pool at a time, with lots of space in between. Instead, the biggest of the Shearon Harris pools today holds almost 3,000 assemblies, and the four pools, when full, would contain more than 8,000--versus the 157 in a functioning reactor core.
David Lochbaum, a nuclear engineer with the Union of Concerned Scientists, argues that while there is no fool-proof method of nuclear waste storage, using dry casks is safer than pools. The reinforced-concrete casks--think of a mummy's tomb--hold a relatively small number of fuel assemblies (generally, 50 or less), few enough so they don't require water to stop a radiation release. Also, the casks themselves can be spread out across a larger area, so that if one cask is hit it needn't affect the others.
Before Sept. 11, CP&L rejected all talk about casks on grounds that buying them would be a useless expense, since the pool-storage method could not possibly fail. N.C. WARN's Jim Warren thinks CP&L should empty its pools, or else repack them so there's much more space in between the assemblies, and stop taking wastes from Southport and Hartsville.
On with our questions:
5. Does CP&L accept Thompson's hypothesis that an exothermic chain reaction could result if the pools lose water? Has the company calculated the chance of that happening and the prospective damage if it does?
6. Is the chance of exothermic reaction reduced by packing the fuel assemblies less tightly together in the pools?
7. What is the cost, including security, of shipping nuclear wastes to Shearon Harris?
8. How do you assess the risk of terrorist attack against the trains used to carry that waste?
9. How much would dry casks cost if used at Shearon Harris and CP&L's other plants? How long would the casks last?
10. Is there an additional cost to defending casks from attack over a large land area?
11. Have you shared your risk assessments and security needs with the Easley administration?
12. Should the state consider paying some portion of the added costs of security at its nuclear plants in light of Sept. 11?
N.C. WARN's series of local meetings is continuing. For information, call (919) 490-0747.